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<div class="title">container_names.cc</div> </div>
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<div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno"> 1</span> <span class="comment">// Copyright (c) 2013 The Chromium Authors. All rights reserved.</span></div>
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<div class="line"><a name="l00002"></a><span class="lineno"> 2</span> <span class="comment">// Use of this source code is governed by a BSD-style license that can be</span></div>
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<div class="line"><a name="l00003"></a><span class="lineno"> 3</span> <span class="comment">// found in the LICENSE file.</span></div>
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<div class="line"><a name="l00004"></a><span class="lineno"> 4</span> </div>
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<div class="line"><a name="l00005"></a><span class="lineno"> 5</span> <span class="preprocessor">#include "packager/media/base/container_names.h"</span></div>
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<div class="line"><a name="l00006"></a><span class="lineno"> 6</span> </div>
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<div class="line"><a name="l00007"></a><span class="lineno"> 7</span> <span class="preprocessor">#include <libxml/parser.h></span></div>
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<div class="line"><a name="l00008"></a><span class="lineno"> 8</span> <span class="preprocessor">#include <libxml/tree.h></span></div>
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<div class="line"><a name="l00009"></a><span class="lineno"> 9</span> <span class="preprocessor">#include <stdint.h></span></div>
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<div class="line"><a name="l00010"></a><span class="lineno"> 10</span> </div>
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<div class="line"><a name="l00011"></a><span class="lineno"> 11</span> <span class="preprocessor">#include <cctype></span></div>
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<div class="line"><a name="l00012"></a><span class="lineno"> 12</span> <span class="preprocessor">#include <limits></span></div>
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<div class="line"><a name="l00013"></a><span class="lineno"> 13</span> </div>
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<div class="line"><a name="l00014"></a><span class="lineno"> 14</span> <span class="preprocessor">#include "packager/base/logging.h"</span></div>
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<div class="line"><a name="l00015"></a><span class="lineno"> 15</span> <span class="preprocessor">#include "packager/base/strings/string_util.h"</span></div>
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<div class="line"><a name="l00016"></a><span class="lineno"> 16</span> <span class="preprocessor">#include "packager/media/base/bit_reader.h"</span></div>
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<div class="line"><a name="l00017"></a><span class="lineno"> 17</span> <span class="preprocessor">#include "packager/mpd/base/xml/scoped_xml_ptr.h"</span></div>
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<div class="line"><a name="l00018"></a><span class="lineno"> 18</span> </div>
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<div class="line"><a name="l00019"></a><span class="lineno"> 19</span> <span class="keyword">namespace </span>shaka {</div>
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<div class="line"><a name="l00020"></a><span class="lineno"> 20</span> <span class="keyword">namespace </span>media {</div>
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<div class="line"><a name="l00021"></a><span class="lineno"> 21</span> </div>
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<div class="line"><a name="l00022"></a><span class="lineno"> 22</span> <span class="preprocessor">#define TAG(a, b, c, d) \</span></div>
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<div class="line"><a name="l00023"></a><span class="lineno"> 23</span> <span class="preprocessor"> ((static_cast<uint32_t>(static_cast<uint8_t>(a)) << 24) | \</span></div>
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<div class="line"><a name="l00024"></a><span class="lineno"> 24</span> <span class="preprocessor"> (static_cast<uint8_t>(b) << 16) | (static_cast<uint8_t>(c) << 8) | \</span></div>
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<div class="line"><a name="l00025"></a><span class="lineno"> 25</span> <span class="preprocessor"> (static_cast<uint8_t>(d)))</span></div>
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<div class="line"><a name="l00026"></a><span class="lineno"> 26</span> <span class="preprocessor"></span></div>
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<div class="line"><a name="l00027"></a><span class="lineno"> 27</span> <span class="preprocessor">#define RCHECK(x) \</span></div>
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<div class="line"><a name="l00028"></a><span class="lineno"> 28</span> <span class="preprocessor"> do { \</span></div>
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<div class="line"><a name="l00029"></a><span class="lineno"> 29</span> <span class="preprocessor"> if (!(x)) \</span></div>
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<div class="line"><a name="l00030"></a><span class="lineno"> 30</span> <span class="preprocessor"> return false; \</span></div>
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<div class="line"><a name="l00031"></a><span class="lineno"> 31</span> <span class="preprocessor"> } while (0)</span></div>
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<div class="line"><a name="l00032"></a><span class="lineno"> 32</span> <span class="preprocessor"></span></div>
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<div class="line"><a name="l00033"></a><span class="lineno"> 33</span> <span class="preprocessor">#define UTF8_BYTE_ORDER_MARK "\xef\xbb\xbf"</span></div>
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<div class="line"><a name="l00034"></a><span class="lineno"> 34</span> <span class="preprocessor"></span></div>
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<div class="line"><a name="l00035"></a><span class="lineno"> 35</span> <span class="comment">// Helper function to read 2 bytes (16 bits, big endian) from a buffer.</span></div>
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<div class="line"><a name="l00036"></a><span class="lineno"> 36</span> <span class="keyword">static</span> <span class="keywordtype">int</span> Read16(<span class="keyword">const</span> uint8_t* p) {</div>
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<div class="line"><a name="l00037"></a><span class="lineno"> 37</span>  <span class="keywordflow">return</span> p[0] << 8 | p[1];</div>
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<div class="line"><a name="l00038"></a><span class="lineno"> 38</span> }</div>
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<div class="line"><a name="l00039"></a><span class="lineno"> 39</span> </div>
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<div class="line"><a name="l00040"></a><span class="lineno"> 40</span> <span class="comment">// Helper function to read 3 bytes (24 bits, big endian) from a buffer.</span></div>
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<div class="line"><a name="l00041"></a><span class="lineno"> 41</span> <span class="keyword">static</span> uint32_t Read24(<span class="keyword">const</span> uint8_t* p) {</div>
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<div class="line"><a name="l00042"></a><span class="lineno"> 42</span>  <span class="keywordflow">return</span> p[0] << 16 | p[1] << 8 | p[2];</div>
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<div class="line"><a name="l00043"></a><span class="lineno"> 43</span> }</div>
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<div class="line"><a name="l00044"></a><span class="lineno"> 44</span> </div>
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<div class="line"><a name="l00045"></a><span class="lineno"> 45</span> <span class="comment">// Helper function to read 4 bytes (32 bits, big endian) from a buffer.</span></div>
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<div class="line"><a name="l00046"></a><span class="lineno"> 46</span> <span class="keyword">static</span> uint32_t Read32(<span class="keyword">const</span> uint8_t* p) {</div>
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<div class="line"><a name="l00047"></a><span class="lineno"> 47</span>  <span class="keywordflow">return</span> p[0] << 24 | p[1] << 16 | p[2] << 8 | p[3];</div>
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<div class="line"><a name="l00048"></a><span class="lineno"> 48</span> }</div>
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<div class="line"><a name="l00049"></a><span class="lineno"> 49</span> </div>
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<div class="line"><a name="l00050"></a><span class="lineno"> 50</span> <span class="comment">// Helper function to read 4 bytes (32 bits, little endian) from a buffer.</span></div>
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<div class="line"><a name="l00051"></a><span class="lineno"> 51</span> <span class="keyword">static</span> uint32_t Read32LE(<span class="keyword">const</span> uint8_t* p) {</div>
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<div class="line"><a name="l00052"></a><span class="lineno"> 52</span>  <span class="keywordflow">return</span> p[3] << 24 | p[2] << 16 | p[1] << 8 | p[0];</div>
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<div class="line"><a name="l00053"></a><span class="lineno"> 53</span> }</div>
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<div class="line"><a name="l00054"></a><span class="lineno"> 54</span> </div>
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<div class="line"><a name="l00055"></a><span class="lineno"> 55</span> <span class="comment">// Helper function to do buffer comparisons with a string without going off the</span></div>
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<div class="line"><a name="l00056"></a><span class="lineno"> 56</span> <span class="comment">// end of the buffer.</span></div>
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<div class="line"><a name="l00057"></a><span class="lineno"> 57</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> StartsWith(<span class="keyword">const</span> uint8_t* buffer,</div>
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<div class="line"><a name="l00058"></a><span class="lineno"> 58</span>  <span class="keywordtype">size_t</span> buffer_size,</div>
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<div class="line"><a name="l00059"></a><span class="lineno"> 59</span>  <span class="keyword">const</span> <span class="keywordtype">char</span>* prefix) {</div>
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<div class="line"><a name="l00060"></a><span class="lineno"> 60</span>  <span class="keywordtype">size_t</span> prefix_size = strlen(prefix);</div>
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<div class="line"><a name="l00061"></a><span class="lineno"> 61</span>  <span class="keywordflow">return</span> (prefix_size <= buffer_size &&</div>
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<div class="line"><a name="l00062"></a><span class="lineno"> 62</span>  memcmp(buffer, prefix, prefix_size) == 0);</div>
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<div class="line"><a name="l00063"></a><span class="lineno"> 63</span> }</div>
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<div class="line"><a name="l00064"></a><span class="lineno"> 64</span> </div>
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<div class="line"><a name="l00065"></a><span class="lineno"> 65</span> <span class="comment">// Helper function to do buffer comparisons with another buffer (to allow for</span></div>
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|
<div class="line"><a name="l00066"></a><span class="lineno"> 66</span> <span class="comment">// embedded \0 in the comparison) without going off the end of the buffer.</span></div>
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<div class="line"><a name="l00067"></a><span class="lineno"> 67</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> StartsWith(<span class="keyword">const</span> uint8_t* buffer,</div>
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<div class="line"><a name="l00068"></a><span class="lineno"> 68</span>  <span class="keywordtype">size_t</span> buffer_size,</div>
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<div class="line"><a name="l00069"></a><span class="lineno"> 69</span>  <span class="keyword">const</span> uint8_t* prefix,</div>
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<div class="line"><a name="l00070"></a><span class="lineno"> 70</span>  <span class="keywordtype">size_t</span> prefix_size) {</div>
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<div class="line"><a name="l00071"></a><span class="lineno"> 71</span>  <span class="keywordflow">return</span> (prefix_size <= buffer_size &&</div>
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<div class="line"><a name="l00072"></a><span class="lineno"> 72</span>  memcmp(buffer, prefix, prefix_size) == 0);</div>
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<div class="line"><a name="l00073"></a><span class="lineno"> 73</span> }</div>
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<div class="line"><a name="l00074"></a><span class="lineno"> 74</span> </div>
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<div class="line"><a name="l00075"></a><span class="lineno"> 75</span> <span class="comment">// Helper function to read up to 64 bits from a bit stream.</span></div>
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<div class="line"><a name="l00076"></a><span class="lineno"> 76</span> <span class="keyword">static</span> uint64_t ReadBits(BitReader* reader, <span class="keywordtype">int</span> num_bits) {</div>
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<div class="line"><a name="l00077"></a><span class="lineno"> 77</span>  DCHECK_GE(static_cast<int>(reader->bits_available()), num_bits);</div>
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<div class="line"><a name="l00078"></a><span class="lineno"> 78</span>  DCHECK((num_bits > 0) && (num_bits <= 64));</div>
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<div class="line"><a name="l00079"></a><span class="lineno"> 79</span>  uint64_t value;</div>
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<div class="line"><a name="l00080"></a><span class="lineno"> 80</span>  reader->ReadBits(num_bits, &value);</div>
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<div class="line"><a name="l00081"></a><span class="lineno"> 81</span>  <span class="keywordflow">return</span> value;</div>
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<div class="line"><a name="l00082"></a><span class="lineno"> 82</span> }</div>
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<div class="line"><a name="l00083"></a><span class="lineno"> 83</span> </div>
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<div class="line"><a name="l00084"></a><span class="lineno"> 84</span> <span class="keyword">const</span> <span class="keywordtype">int</span> kAc3FrameSizeTable[38][3] = {</div>
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<div class="line"><a name="l00085"></a><span class="lineno"> 85</span>  { 128, 138, 192 }, { 128, 140, 192 }, { 160, 174, 240 }, { 160, 176, 240 },</div>
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<div class="line"><a name="l00086"></a><span class="lineno"> 86</span>  { 192, 208, 288 }, { 192, 210, 288 }, { 224, 242, 336 }, { 224, 244, 336 },</div>
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<div class="line"><a name="l00087"></a><span class="lineno"> 87</span>  { 256, 278, 384 }, { 256, 280, 384 }, { 320, 348, 480 }, { 320, 350, 480 },</div>
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<div class="line"><a name="l00088"></a><span class="lineno"> 88</span>  { 384, 416, 576 }, { 384, 418, 576 }, { 448, 486, 672 }, { 448, 488, 672 },</div>
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<div class="line"><a name="l00089"></a><span class="lineno"> 89</span>  { 512, 556, 768 }, { 512, 558, 768 }, { 640, 696, 960 }, { 640, 698, 960 },</div>
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|
<div class="line"><a name="l00090"></a><span class="lineno"> 90</span>  { 768, 834, 1152 }, { 768, 836, 1152 }, { 896, 974, 1344 },</div>
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<div class="line"><a name="l00091"></a><span class="lineno"> 91</span>  { 896, 976, 1344 }, { 1024, 1114, 1536 }, { 1024, 1116, 1536 },</div>
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|
<div class="line"><a name="l00092"></a><span class="lineno"> 92</span>  { 1280, 1392, 1920 }, { 1280, 1394, 1920 }, { 1536, 1670, 2304 },</div>
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|
<div class="line"><a name="l00093"></a><span class="lineno"> 93</span>  { 1536, 1672, 2304 }, { 1792, 1950, 2688 }, { 1792, 1952, 2688 },</div>
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|
<div class="line"><a name="l00094"></a><span class="lineno"> 94</span>  { 2048, 2228, 3072 }, { 2048, 2230, 3072 }, { 2304, 2506, 3456 },</div>
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|
<div class="line"><a name="l00095"></a><span class="lineno"> 95</span>  { 2304, 2508, 3456 }, { 2560, 2768, 3840 }, { 2560, 2770, 3840 }</div>
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<div class="line"><a name="l00096"></a><span class="lineno"> 96</span> };</div>
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<div class="line"><a name="l00097"></a><span class="lineno"> 97</span> </div>
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<div class="line"><a name="l00098"></a><span class="lineno"> 98</span> <span class="comment">// Checks for an ADTS AAC container.</span></div>
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|
<div class="line"><a name="l00099"></a><span class="lineno"> 99</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckAac(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
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|
<div class="line"><a name="l00100"></a><span class="lineno"> 100</span>  <span class="comment">// Audio Data Transport Stream (ADTS) header is 7 or 9 bytes</span></div>
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|
<div class="line"><a name="l00101"></a><span class="lineno"> 101</span>  <span class="comment">// (from http://wiki.multimedia.cx/index.php?title=ADTS)</span></div>
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<div class="line"><a name="l00102"></a><span class="lineno"> 102</span>  RCHECK(buffer_size > 6);</div>
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<div class="line"><a name="l00103"></a><span class="lineno"> 103</span> </div>
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<div class="line"><a name="l00104"></a><span class="lineno"> 104</span>  <span class="keywordtype">int</span> offset = 0;</div>
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|
<div class="line"><a name="l00105"></a><span class="lineno"> 105</span>  <span class="keywordflow">while</span> (offset + 6 < buffer_size) {</div>
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|
<div class="line"><a name="l00106"></a><span class="lineno"> 106</span>  BitReader reader(buffer + offset, 6);</div>
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|
<div class="line"><a name="l00107"></a><span class="lineno"> 107</span> </div>
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|
<div class="line"><a name="l00108"></a><span class="lineno"> 108</span>  <span class="comment">// Syncword must be 0xfff.</span></div>
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|
<div class="line"><a name="l00109"></a><span class="lineno"> 109</span>  RCHECK(ReadBits(&reader, 12) == 0xfff);</div>
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<div class="line"><a name="l00110"></a><span class="lineno"> 110</span> </div>
|
|
<div class="line"><a name="l00111"></a><span class="lineno"> 111</span>  <span class="comment">// Skip MPEG version.</span></div>
|
|
<div class="line"><a name="l00112"></a><span class="lineno"> 112</span>  reader.SkipBits(1);</div>
|
|
<div class="line"><a name="l00113"></a><span class="lineno"> 113</span> </div>
|
|
<div class="line"><a name="l00114"></a><span class="lineno"> 114</span>  <span class="comment">// Layer is always 0.</span></div>
|
|
<div class="line"><a name="l00115"></a><span class="lineno"> 115</span>  RCHECK(ReadBits(&reader, 2) == 0);</div>
|
|
<div class="line"><a name="l00116"></a><span class="lineno"> 116</span> </div>
|
|
<div class="line"><a name="l00117"></a><span class="lineno"> 117</span>  <span class="comment">// Skip protection + profile.</span></div>
|
|
<div class="line"><a name="l00118"></a><span class="lineno"> 118</span>  reader.SkipBits(1 + 2);</div>
|
|
<div class="line"><a name="l00119"></a><span class="lineno"> 119</span> </div>
|
|
<div class="line"><a name="l00120"></a><span class="lineno"> 120</span>  <span class="comment">// Check sampling frequency index.</span></div>
|
|
<div class="line"><a name="l00121"></a><span class="lineno"> 121</span>  RCHECK(ReadBits(&reader, 4) != 15); <span class="comment">// Forbidden.</span></div>
|
|
<div class="line"><a name="l00122"></a><span class="lineno"> 122</span> </div>
|
|
<div class="line"><a name="l00123"></a><span class="lineno"> 123</span>  <span class="comment">// Skip private stream, channel configuration, originality, home,</span></div>
|
|
<div class="line"><a name="l00124"></a><span class="lineno"> 124</span>  <span class="comment">// copyrighted stream, and copyright_start.</span></div>
|
|
<div class="line"><a name="l00125"></a><span class="lineno"> 125</span>  reader.SkipBits(1 + 3 + 1 + 1 + 1 + 1);</div>
|
|
<div class="line"><a name="l00126"></a><span class="lineno"> 126</span> </div>
|
|
<div class="line"><a name="l00127"></a><span class="lineno"> 127</span>  <span class="comment">// Get frame length (includes header).</span></div>
|
|
<div class="line"><a name="l00128"></a><span class="lineno"> 128</span>  <span class="keywordtype">int</span> size = ReadBits(&reader, 13);</div>
|
|
<div class="line"><a name="l00129"></a><span class="lineno"> 129</span>  RCHECK(size > 0);</div>
|
|
<div class="line"><a name="l00130"></a><span class="lineno"> 130</span>  offset += size;</div>
|
|
<div class="line"><a name="l00131"></a><span class="lineno"> 131</span>  }</div>
|
|
<div class="line"><a name="l00132"></a><span class="lineno"> 132</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00133"></a><span class="lineno"> 133</span> }</div>
|
|
<div class="line"><a name="l00134"></a><span class="lineno"> 134</span> </div>
|
|
<div class="line"><a name="l00135"></a><span class="lineno"> 135</span> <span class="keyword">const</span> uint16_t kAc3SyncWord = 0x0b77;</div>
|
|
<div class="line"><a name="l00136"></a><span class="lineno"> 136</span> </div>
|
|
<div class="line"><a name="l00137"></a><span class="lineno"> 137</span> <span class="comment">// Checks for an AC3 container.</span></div>
|
|
<div class="line"><a name="l00138"></a><span class="lineno"> 138</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckAc3(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00139"></a><span class="lineno"> 139</span>  <span class="comment">// Reference: ATSC Standard: Digital Audio Compression (AC-3, E-AC-3)</span></div>
|
|
<div class="line"><a name="l00140"></a><span class="lineno"> 140</span>  <span class="comment">// Doc. A/52:2012</span></div>
|
|
<div class="line"><a name="l00141"></a><span class="lineno"> 141</span>  <span class="comment">// (http://www.atsc.org/cms/standards/A52-2012(12-17).pdf)</span></div>
|
|
<div class="line"><a name="l00142"></a><span class="lineno"> 142</span> </div>
|
|
<div class="line"><a name="l00143"></a><span class="lineno"> 143</span>  <span class="comment">// AC3 container looks like syncinfo | bsi | audblk * 6 | aux | check.</span></div>
|
|
<div class="line"><a name="l00144"></a><span class="lineno"> 144</span>  RCHECK(buffer_size > 6);</div>
|
|
<div class="line"><a name="l00145"></a><span class="lineno"> 145</span> </div>
|
|
<div class="line"><a name="l00146"></a><span class="lineno"> 146</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l00147"></a><span class="lineno"> 147</span>  <span class="keywordflow">while</span> (offset + 6 < buffer_size) {</div>
|
|
<div class="line"><a name="l00148"></a><span class="lineno"> 148</span>  BitReader reader(buffer + offset, 6);</div>
|
|
<div class="line"><a name="l00149"></a><span class="lineno"> 149</span> </div>
|
|
<div class="line"><a name="l00150"></a><span class="lineno"> 150</span>  <span class="comment">// Check syncinfo.</span></div>
|
|
<div class="line"><a name="l00151"></a><span class="lineno"> 151</span>  RCHECK(ReadBits(&reader, 16) == kAc3SyncWord);</div>
|
|
<div class="line"><a name="l00152"></a><span class="lineno"> 152</span> </div>
|
|
<div class="line"><a name="l00153"></a><span class="lineno"> 153</span>  <span class="comment">// Skip crc1.</span></div>
|
|
<div class="line"><a name="l00154"></a><span class="lineno"> 154</span>  reader.SkipBits(16);</div>
|
|
<div class="line"><a name="l00155"></a><span class="lineno"> 155</span> </div>
|
|
<div class="line"><a name="l00156"></a><span class="lineno"> 156</span>  <span class="comment">// Verify fscod.</span></div>
|
|
<div class="line"><a name="l00157"></a><span class="lineno"> 157</span>  <span class="keywordtype">int</span> sample_rate_code = ReadBits(&reader, 2);</div>
|
|
<div class="line"><a name="l00158"></a><span class="lineno"> 158</span>  RCHECK(sample_rate_code != 3); <span class="comment">// Reserved.</span></div>
|
|
<div class="line"><a name="l00159"></a><span class="lineno"> 159</span> </div>
|
|
<div class="line"><a name="l00160"></a><span class="lineno"> 160</span>  <span class="comment">// Verify frmsizecod.</span></div>
|
|
<div class="line"><a name="l00161"></a><span class="lineno"> 161</span>  <span class="keywordtype">int</span> frame_size_code = ReadBits(&reader, 6);</div>
|
|
<div class="line"><a name="l00162"></a><span class="lineno"> 162</span>  RCHECK(frame_size_code < 38); <span class="comment">// Undefined.</span></div>
|
|
<div class="line"><a name="l00163"></a><span class="lineno"> 163</span> </div>
|
|
<div class="line"><a name="l00164"></a><span class="lineno"> 164</span>  <span class="comment">// Verify bsid.</span></div>
|
|
<div class="line"><a name="l00165"></a><span class="lineno"> 165</span>  RCHECK(ReadBits(&reader, 5) < 10); <span class="comment">// Normally 8 or 6, 16 used by EAC3.</span></div>
|
|
<div class="line"><a name="l00166"></a><span class="lineno"> 166</span> </div>
|
|
<div class="line"><a name="l00167"></a><span class="lineno"> 167</span>  offset += kAc3FrameSizeTable[frame_size_code][sample_rate_code];</div>
|
|
<div class="line"><a name="l00168"></a><span class="lineno"> 168</span>  }</div>
|
|
<div class="line"><a name="l00169"></a><span class="lineno"> 169</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00170"></a><span class="lineno"> 170</span> }</div>
|
|
<div class="line"><a name="l00171"></a><span class="lineno"> 171</span> </div>
|
|
<div class="line"><a name="l00172"></a><span class="lineno"> 172</span> <span class="comment">// Checks for an EAC3 container (very similar to AC3)</span></div>
|
|
<div class="line"><a name="l00173"></a><span class="lineno"> 173</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckEac3(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00174"></a><span class="lineno"> 174</span>  <span class="comment">// Reference: ATSC Standard: Digital Audio Compression (AC-3, E-AC-3)</span></div>
|
|
<div class="line"><a name="l00175"></a><span class="lineno"> 175</span>  <span class="comment">// Doc. A/52:2012</span></div>
|
|
<div class="line"><a name="l00176"></a><span class="lineno"> 176</span>  <span class="comment">// (http://www.atsc.org/cms/standards/A52-2012(12-17).pdf)</span></div>
|
|
<div class="line"><a name="l00177"></a><span class="lineno"> 177</span> </div>
|
|
<div class="line"><a name="l00178"></a><span class="lineno"> 178</span>  <span class="comment">// EAC3 container looks like syncinfo | bsi | audfrm | audblk* | aux | check.</span></div>
|
|
<div class="line"><a name="l00179"></a><span class="lineno"> 179</span>  RCHECK(buffer_size > 6);</div>
|
|
<div class="line"><a name="l00180"></a><span class="lineno"> 180</span> </div>
|
|
<div class="line"><a name="l00181"></a><span class="lineno"> 181</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l00182"></a><span class="lineno"> 182</span>  <span class="keywordflow">while</span> (offset + 6 < buffer_size) {</div>
|
|
<div class="line"><a name="l00183"></a><span class="lineno"> 183</span>  BitReader reader(buffer + offset, 6);</div>
|
|
<div class="line"><a name="l00184"></a><span class="lineno"> 184</span> </div>
|
|
<div class="line"><a name="l00185"></a><span class="lineno"> 185</span>  <span class="comment">// Check syncinfo.</span></div>
|
|
<div class="line"><a name="l00186"></a><span class="lineno"> 186</span>  RCHECK(ReadBits(&reader, 16) == kAc3SyncWord);</div>
|
|
<div class="line"><a name="l00187"></a><span class="lineno"> 187</span> </div>
|
|
<div class="line"><a name="l00188"></a><span class="lineno"> 188</span>  <span class="comment">// Verify strmtyp.</span></div>
|
|
<div class="line"><a name="l00189"></a><span class="lineno"> 189</span>  RCHECK(ReadBits(&reader, 2) != 3);</div>
|
|
<div class="line"><a name="l00190"></a><span class="lineno"> 190</span> </div>
|
|
<div class="line"><a name="l00191"></a><span class="lineno"> 191</span>  <span class="comment">// Skip substreamid.</span></div>
|
|
<div class="line"><a name="l00192"></a><span class="lineno"> 192</span>  reader.SkipBits(3);</div>
|
|
<div class="line"><a name="l00193"></a><span class="lineno"> 193</span> </div>
|
|
<div class="line"><a name="l00194"></a><span class="lineno"> 194</span>  <span class="comment">// Get frmsize. Include syncinfo size and convert to bytes.</span></div>
|
|
<div class="line"><a name="l00195"></a><span class="lineno"> 195</span>  <span class="keywordtype">int</span> frame_size = (ReadBits(&reader, 11) + 1) * 2;</div>
|
|
<div class="line"><a name="l00196"></a><span class="lineno"> 196</span>  RCHECK(frame_size >= 7);</div>
|
|
<div class="line"><a name="l00197"></a><span class="lineno"> 197</span> </div>
|
|
<div class="line"><a name="l00198"></a><span class="lineno"> 198</span>  <span class="comment">// Skip fscod, fscod2, acmod, and lfeon.</span></div>
|
|
<div class="line"><a name="l00199"></a><span class="lineno"> 199</span>  reader.SkipBits(2 + 2 + 3 + 1);</div>
|
|
<div class="line"><a name="l00200"></a><span class="lineno"> 200</span> </div>
|
|
<div class="line"><a name="l00201"></a><span class="lineno"> 201</span>  <span class="comment">// Verify bsid.</span></div>
|
|
<div class="line"><a name="l00202"></a><span class="lineno"> 202</span>  <span class="keywordtype">int</span> bit_stream_id = ReadBits(&reader, 5);</div>
|
|
<div class="line"><a name="l00203"></a><span class="lineno"> 203</span>  RCHECK(bit_stream_id >= 11 && bit_stream_id <= 16);</div>
|
|
<div class="line"><a name="l00204"></a><span class="lineno"> 204</span> </div>
|
|
<div class="line"><a name="l00205"></a><span class="lineno"> 205</span>  offset += frame_size;</div>
|
|
<div class="line"><a name="l00206"></a><span class="lineno"> 206</span>  }</div>
|
|
<div class="line"><a name="l00207"></a><span class="lineno"> 207</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00208"></a><span class="lineno"> 208</span> }</div>
|
|
<div class="line"><a name="l00209"></a><span class="lineno"> 209</span> </div>
|
|
<div class="line"><a name="l00210"></a><span class="lineno"> 210</span> <span class="comment">// Additional checks for a BINK container.</span></div>
|
|
<div class="line"><a name="l00211"></a><span class="lineno"> 211</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckBink(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00212"></a><span class="lineno"> 212</span>  <span class="comment">// Reference: http://wiki.multimedia.cx/index.php?title=Bink_Container</span></div>
|
|
<div class="line"><a name="l00213"></a><span class="lineno"> 213</span>  RCHECK(buffer_size >= 44);</div>
|
|
<div class="line"><a name="l00214"></a><span class="lineno"> 214</span> </div>
|
|
<div class="line"><a name="l00215"></a><span class="lineno"> 215</span>  <span class="comment">// Verify number of frames specified.</span></div>
|
|
<div class="line"><a name="l00216"></a><span class="lineno"> 216</span>  RCHECK(Read32LE(buffer + 8) > 0);</div>
|
|
<div class="line"><a name="l00217"></a><span class="lineno"> 217</span> </div>
|
|
<div class="line"><a name="l00218"></a><span class="lineno"> 218</span>  <span class="comment">// Verify width in range.</span></div>
|
|
<div class="line"><a name="l00219"></a><span class="lineno"> 219</span>  <span class="keywordtype">int</span> width = Read32LE(buffer + 20);</div>
|
|
<div class="line"><a name="l00220"></a><span class="lineno"> 220</span>  RCHECK(width > 0 && width <= 32767);</div>
|
|
<div class="line"><a name="l00221"></a><span class="lineno"> 221</span> </div>
|
|
<div class="line"><a name="l00222"></a><span class="lineno"> 222</span>  <span class="comment">// Verify height in range.</span></div>
|
|
<div class="line"><a name="l00223"></a><span class="lineno"> 223</span>  <span class="keywordtype">int</span> height = Read32LE(buffer + 24);</div>
|
|
<div class="line"><a name="l00224"></a><span class="lineno"> 224</span>  RCHECK(height > 0 && height <= 32767);</div>
|
|
<div class="line"><a name="l00225"></a><span class="lineno"> 225</span> </div>
|
|
<div class="line"><a name="l00226"></a><span class="lineno"> 226</span>  <span class="comment">// Verify frames per second specified.</span></div>
|
|
<div class="line"><a name="l00227"></a><span class="lineno"> 227</span>  RCHECK(Read32LE(buffer + 28) > 0);</div>
|
|
<div class="line"><a name="l00228"></a><span class="lineno"> 228</span> </div>
|
|
<div class="line"><a name="l00229"></a><span class="lineno"> 229</span>  <span class="comment">// Verify video frames per second specified.</span></div>
|
|
<div class="line"><a name="l00230"></a><span class="lineno"> 230</span>  RCHECK(Read32LE(buffer + 32) > 0);</div>
|
|
<div class="line"><a name="l00231"></a><span class="lineno"> 231</span> </div>
|
|
<div class="line"><a name="l00232"></a><span class="lineno"> 232</span>  <span class="comment">// Number of audio tracks must be 256 or less.</span></div>
|
|
<div class="line"><a name="l00233"></a><span class="lineno"> 233</span>  <span class="keywordflow">return</span> (Read32LE(buffer + 40) <= 256);</div>
|
|
<div class="line"><a name="l00234"></a><span class="lineno"> 234</span> }</div>
|
|
<div class="line"><a name="l00235"></a><span class="lineno"> 235</span> </div>
|
|
<div class="line"><a name="l00236"></a><span class="lineno"> 236</span> <span class="comment">// Additional checks for a CAF container.</span></div>
|
|
<div class="line"><a name="l00237"></a><span class="lineno"> 237</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckCaf(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00238"></a><span class="lineno"> 238</span>  <span class="comment">// Reference: Apple Core Audio Format Specification 1.0</span></div>
|
|
<div class="line"><a name="l00239"></a><span class="lineno"> 239</span>  <span class="comment">// (https://developer.apple.com/library/mac/#documentation/MusicAudio/Reference/CAFSpec/CAF_spec/CAF_spec.html)</span></div>
|
|
<div class="line"><a name="l00240"></a><span class="lineno"> 240</span>  RCHECK(buffer_size >= 52);</div>
|
|
<div class="line"><a name="l00241"></a><span class="lineno"> 241</span>  BitReader reader(buffer, buffer_size);</div>
|
|
<div class="line"><a name="l00242"></a><span class="lineno"> 242</span> </div>
|
|
<div class="line"><a name="l00243"></a><span class="lineno"> 243</span>  <span class="comment">// mFileType should be "caff".</span></div>
|
|
<div class="line"><a name="l00244"></a><span class="lineno"> 244</span>  RCHECK(ReadBits(&reader, 32) == TAG(<span class="charliteral">'c'</span>, <span class="charliteral">'a'</span>, <span class="charliteral">'f'</span>, <span class="charliteral">'f'</span>));</div>
|
|
<div class="line"><a name="l00245"></a><span class="lineno"> 245</span> </div>
|
|
<div class="line"><a name="l00246"></a><span class="lineno"> 246</span>  <span class="comment">// mFileVersion should be 1.</span></div>
|
|
<div class="line"><a name="l00247"></a><span class="lineno"> 247</span>  RCHECK(ReadBits(&reader, 16) == 1);</div>
|
|
<div class="line"><a name="l00248"></a><span class="lineno"> 248</span> </div>
|
|
<div class="line"><a name="l00249"></a><span class="lineno"> 249</span>  <span class="comment">// Skip mFileFlags.</span></div>
|
|
<div class="line"><a name="l00250"></a><span class="lineno"> 250</span>  reader.SkipBits(16);</div>
|
|
<div class="line"><a name="l00251"></a><span class="lineno"> 251</span> </div>
|
|
<div class="line"><a name="l00252"></a><span class="lineno"> 252</span>  <span class="comment">// First chunk should be Audio Description chunk, size 32l.</span></div>
|
|
<div class="line"><a name="l00253"></a><span class="lineno"> 253</span>  RCHECK(ReadBits(&reader, 32) == TAG(<span class="charliteral">'d'</span>, <span class="charliteral">'e'</span>, <span class="charliteral">'s'</span>, <span class="charliteral">'c'</span>));</div>
|
|
<div class="line"><a name="l00254"></a><span class="lineno"> 254</span>  RCHECK(ReadBits(&reader, 64) == 32);</div>
|
|
<div class="line"><a name="l00255"></a><span class="lineno"> 255</span> </div>
|
|
<div class="line"><a name="l00256"></a><span class="lineno"> 256</span>  <span class="comment">// CAFAudioFormat.mSampleRate(float64) not 0</span></div>
|
|
<div class="line"><a name="l00257"></a><span class="lineno"> 257</span>  RCHECK(ReadBits(&reader, 64) != 0);</div>
|
|
<div class="line"><a name="l00258"></a><span class="lineno"> 258</span> </div>
|
|
<div class="line"><a name="l00259"></a><span class="lineno"> 259</span>  <span class="comment">// CAFAudioFormat.mFormatID not 0</span></div>
|
|
<div class="line"><a name="l00260"></a><span class="lineno"> 260</span>  RCHECK(ReadBits(&reader, 32) != 0);</div>
|
|
<div class="line"><a name="l00261"></a><span class="lineno"> 261</span> </div>
|
|
<div class="line"><a name="l00262"></a><span class="lineno"> 262</span>  <span class="comment">// Skip CAFAudioFormat.mBytesPerPacket and mFramesPerPacket.</span></div>
|
|
<div class="line"><a name="l00263"></a><span class="lineno"> 263</span>  reader.SkipBits(32 + 32);</div>
|
|
<div class="line"><a name="l00264"></a><span class="lineno"> 264</span> </div>
|
|
<div class="line"><a name="l00265"></a><span class="lineno"> 265</span>  <span class="comment">// CAFAudioFormat.mChannelsPerFrame not 0</span></div>
|
|
<div class="line"><a name="l00266"></a><span class="lineno"> 266</span>  RCHECK(ReadBits(&reader, 32) != 0);</div>
|
|
<div class="line"><a name="l00267"></a><span class="lineno"> 267</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00268"></a><span class="lineno"> 268</span> }</div>
|
|
<div class="line"><a name="l00269"></a><span class="lineno"> 269</span> </div>
|
|
<div class="line"><a name="l00270"></a><span class="lineno"> 270</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> kSamplingFrequencyValid[16] = { <span class="keyword">false</span>, <span class="keyword">true</span>, <span class="keyword">true</span>, <span class="keyword">true</span>, <span class="keyword">false</span>,</div>
|
|
<div class="line"><a name="l00271"></a><span class="lineno"> 271</span>  <span class="keyword">false</span>, <span class="keyword">true</span>, <span class="keyword">true</span>, <span class="keyword">true</span>, <span class="keyword">false</span>,</div>
|
|
<div class="line"><a name="l00272"></a><span class="lineno"> 272</span>  <span class="keyword">false</span>, <span class="keyword">true</span>, <span class="keyword">true</span>, <span class="keyword">true</span>, <span class="keyword">false</span>,</div>
|
|
<div class="line"><a name="l00273"></a><span class="lineno"> 273</span>  <span class="keyword">false</span> };</div>
|
|
<div class="line"><a name="l00274"></a><span class="lineno"> 274</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> kExtAudioIdValid[8] = { <span class="keyword">true</span>, <span class="keyword">false</span>, <span class="keyword">true</span>, <span class="keyword">false</span>, <span class="keyword">false</span>, <span class="keyword">false</span>,</div>
|
|
<div class="line"><a name="l00275"></a><span class="lineno"> 275</span>  <span class="keyword">true</span>, <span class="keyword">false</span> };</div>
|
|
<div class="line"><a name="l00276"></a><span class="lineno"> 276</span> </div>
|
|
<div class="line"><a name="l00277"></a><span class="lineno"> 277</span> <span class="comment">// Additional checks for a DTS container.</span></div>
|
|
<div class="line"><a name="l00278"></a><span class="lineno"> 278</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckDts(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00279"></a><span class="lineno"> 279</span>  <span class="comment">// Reference: ETSI TS 102 114 V1.3.1 (2011-08)</span></div>
|
|
<div class="line"><a name="l00280"></a><span class="lineno"> 280</span>  <span class="comment">// (http://www.etsi.org/deliver/etsi_ts/102100_102199/102114/01.03.01_60/ts_102114v010301p.pdf)</span></div>
|
|
<div class="line"><a name="l00281"></a><span class="lineno"> 281</span>  RCHECK(buffer_size > 11);</div>
|
|
<div class="line"><a name="l00282"></a><span class="lineno"> 282</span> </div>
|
|
<div class="line"><a name="l00283"></a><span class="lineno"> 283</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l00284"></a><span class="lineno"> 284</span>  <span class="keywordflow">while</span> (offset + 11 < buffer_size) {</div>
|
|
<div class="line"><a name="l00285"></a><span class="lineno"> 285</span>  BitReader reader(buffer + offset, 11);</div>
|
|
<div class="line"><a name="l00286"></a><span class="lineno"> 286</span> </div>
|
|
<div class="line"><a name="l00287"></a><span class="lineno"> 287</span>  <span class="comment">// Verify sync word.</span></div>
|
|
<div class="line"><a name="l00288"></a><span class="lineno"> 288</span>  RCHECK(ReadBits(&reader, 32) == 0x7ffe8001);</div>
|
|
<div class="line"><a name="l00289"></a><span class="lineno"> 289</span> </div>
|
|
<div class="line"><a name="l00290"></a><span class="lineno"> 290</span>  <span class="comment">// Skip frame type and deficit sample count.</span></div>
|
|
<div class="line"><a name="l00291"></a><span class="lineno"> 291</span>  reader.SkipBits(1 + 5);</div>
|
|
<div class="line"><a name="l00292"></a><span class="lineno"> 292</span> </div>
|
|
<div class="line"><a name="l00293"></a><span class="lineno"> 293</span>  <span class="comment">// Verify CRC present flag.</span></div>
|
|
<div class="line"><a name="l00294"></a><span class="lineno"> 294</span>  RCHECK(ReadBits(&reader, 1) == 0); <span class="comment">// CPF must be 0.</span></div>
|
|
<div class="line"><a name="l00295"></a><span class="lineno"> 295</span> </div>
|
|
<div class="line"><a name="l00296"></a><span class="lineno"> 296</span>  <span class="comment">// Verify number of PCM sample blocks.</span></div>
|
|
<div class="line"><a name="l00297"></a><span class="lineno"> 297</span>  RCHECK(ReadBits(&reader, 7) >= 5);</div>
|
|
<div class="line"><a name="l00298"></a><span class="lineno"> 298</span> </div>
|
|
<div class="line"><a name="l00299"></a><span class="lineno"> 299</span>  <span class="comment">// Verify primary frame byte size.</span></div>
|
|
<div class="line"><a name="l00300"></a><span class="lineno"> 300</span>  <span class="keywordtype">int</span> frame_size = ReadBits(&reader, 14);</div>
|
|
<div class="line"><a name="l00301"></a><span class="lineno"> 301</span>  RCHECK(frame_size >= 95);</div>
|
|
<div class="line"><a name="l00302"></a><span class="lineno"> 302</span> </div>
|
|
<div class="line"><a name="l00303"></a><span class="lineno"> 303</span>  <span class="comment">// Skip audio channel arrangement.</span></div>
|
|
<div class="line"><a name="l00304"></a><span class="lineno"> 304</span>  reader.SkipBits(6);</div>
|
|
<div class="line"><a name="l00305"></a><span class="lineno"> 305</span> </div>
|
|
<div class="line"><a name="l00306"></a><span class="lineno"> 306</span>  <span class="comment">// Verify core audio sampling frequency is an allowed value.</span></div>
|
|
<div class="line"><a name="l00307"></a><span class="lineno"> 307</span>  RCHECK(kSamplingFrequencyValid[ReadBits(&reader, 4)]);</div>
|
|
<div class="line"><a name="l00308"></a><span class="lineno"> 308</span> </div>
|
|
<div class="line"><a name="l00309"></a><span class="lineno"> 309</span>  <span class="comment">// Verify transmission bit rate is valid.</span></div>
|
|
<div class="line"><a name="l00310"></a><span class="lineno"> 310</span>  RCHECK(ReadBits(&reader, 5) <= 25);</div>
|
|
<div class="line"><a name="l00311"></a><span class="lineno"> 311</span> </div>
|
|
<div class="line"><a name="l00312"></a><span class="lineno"> 312</span>  <span class="comment">// Verify reserved field is 0.</span></div>
|
|
<div class="line"><a name="l00313"></a><span class="lineno"> 313</span>  RCHECK(ReadBits(&reader, 1) == 0);</div>
|
|
<div class="line"><a name="l00314"></a><span class="lineno"> 314</span> </div>
|
|
<div class="line"><a name="l00315"></a><span class="lineno"> 315</span>  <span class="comment">// Skip dynamic range flag, time stamp flag, auxiliary data flag, and HDCD.</span></div>
|
|
<div class="line"><a name="l00316"></a><span class="lineno"> 316</span>  reader.SkipBits(1 + 1 + 1 + 1);</div>
|
|
<div class="line"><a name="l00317"></a><span class="lineno"> 317</span> </div>
|
|
<div class="line"><a name="l00318"></a><span class="lineno"> 318</span>  <span class="comment">// Verify extension audio descriptor flag is an allowed value.</span></div>
|
|
<div class="line"><a name="l00319"></a><span class="lineno"> 319</span>  RCHECK(kExtAudioIdValid[ReadBits(&reader, 3)]);</div>
|
|
<div class="line"><a name="l00320"></a><span class="lineno"> 320</span> </div>
|
|
<div class="line"><a name="l00321"></a><span class="lineno"> 321</span>  <span class="comment">// Skip extended coding flag and audio sync word insertion flag.</span></div>
|
|
<div class="line"><a name="l00322"></a><span class="lineno"> 322</span>  reader.SkipBits(1 + 1);</div>
|
|
<div class="line"><a name="l00323"></a><span class="lineno"> 323</span> </div>
|
|
<div class="line"><a name="l00324"></a><span class="lineno"> 324</span>  <span class="comment">// Verify low frequency effects flag is an allowed value.</span></div>
|
|
<div class="line"><a name="l00325"></a><span class="lineno"> 325</span>  RCHECK(ReadBits(&reader, 2) != 3);</div>
|
|
<div class="line"><a name="l00326"></a><span class="lineno"> 326</span> </div>
|
|
<div class="line"><a name="l00327"></a><span class="lineno"> 327</span>  offset += frame_size + 1;</div>
|
|
<div class="line"><a name="l00328"></a><span class="lineno"> 328</span>  }</div>
|
|
<div class="line"><a name="l00329"></a><span class="lineno"> 329</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00330"></a><span class="lineno"> 330</span> }</div>
|
|
<div class="line"><a name="l00331"></a><span class="lineno"> 331</span> </div>
|
|
<div class="line"><a name="l00332"></a><span class="lineno"> 332</span> <span class="comment">// Checks for a DV container.</span></div>
|
|
<div class="line"><a name="l00333"></a><span class="lineno"> 333</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckDV(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00334"></a><span class="lineno"> 334</span>  <span class="comment">// Reference: SMPTE 314M (Annex A has differences with IEC 61834).</span></div>
|
|
<div class="line"><a name="l00335"></a><span class="lineno"> 335</span>  <span class="comment">// (http://standards.smpte.org/content/978-1-61482-454-1/st-314-2005/SEC1.body.pdf)</span></div>
|
|
<div class="line"><a name="l00336"></a><span class="lineno"> 336</span>  RCHECK(buffer_size > 11);</div>
|
|
<div class="line"><a name="l00337"></a><span class="lineno"> 337</span> </div>
|
|
<div class="line"><a name="l00338"></a><span class="lineno"> 338</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l00339"></a><span class="lineno"> 339</span>  <span class="keywordtype">int</span> current_sequence_number = -1;</div>
|
|
<div class="line"><a name="l00340"></a><span class="lineno"> 340</span>  <span class="keywordtype">int</span> last_block_number[6];</div>
|
|
<div class="line"><a name="l00341"></a><span class="lineno"> 341</span>  <span class="keywordflow">while</span> (offset + 11 < buffer_size) {</div>
|
|
<div class="line"><a name="l00342"></a><span class="lineno"> 342</span>  BitReader reader(buffer + offset, 11);</div>
|
|
<div class="line"><a name="l00343"></a><span class="lineno"> 343</span> </div>
|
|
<div class="line"><a name="l00344"></a><span class="lineno"> 344</span>  <span class="comment">// Decode ID data. Sections 5, 6, and 7 are reserved.</span></div>
|
|
<div class="line"><a name="l00345"></a><span class="lineno"> 345</span>  <span class="keywordtype">int</span> section = ReadBits(&reader, 3);</div>
|
|
<div class="line"><a name="l00346"></a><span class="lineno"> 346</span>  RCHECK(section < 5);</div>
|
|
<div class="line"><a name="l00347"></a><span class="lineno"> 347</span> </div>
|
|
<div class="line"><a name="l00348"></a><span class="lineno"> 348</span>  <span class="comment">// Next bit must be 1.</span></div>
|
|
<div class="line"><a name="l00349"></a><span class="lineno"> 349</span>  RCHECK(ReadBits(&reader, 1) == 1);</div>
|
|
<div class="line"><a name="l00350"></a><span class="lineno"> 350</span> </div>
|
|
<div class="line"><a name="l00351"></a><span class="lineno"> 351</span>  <span class="comment">// Skip arbitrary bits.</span></div>
|
|
<div class="line"><a name="l00352"></a><span class="lineno"> 352</span>  reader.SkipBits(4);</div>
|
|
<div class="line"><a name="l00353"></a><span class="lineno"> 353</span> </div>
|
|
<div class="line"><a name="l00354"></a><span class="lineno"> 354</span>  <span class="keywordtype">int</span> sequence_number = ReadBits(&reader, 4);</div>
|
|
<div class="line"><a name="l00355"></a><span class="lineno"> 355</span> </div>
|
|
<div class="line"><a name="l00356"></a><span class="lineno"> 356</span>  <span class="comment">// Skip FSC.</span></div>
|
|
<div class="line"><a name="l00357"></a><span class="lineno"> 357</span>  reader.SkipBits(1);</div>
|
|
<div class="line"><a name="l00358"></a><span class="lineno"> 358</span> </div>
|
|
<div class="line"><a name="l00359"></a><span class="lineno"> 359</span>  <span class="comment">// Next 3 bits must be 1.</span></div>
|
|
<div class="line"><a name="l00360"></a><span class="lineno"> 360</span>  RCHECK(ReadBits(&reader, 3) == 7);</div>
|
|
<div class="line"><a name="l00361"></a><span class="lineno"> 361</span> </div>
|
|
<div class="line"><a name="l00362"></a><span class="lineno"> 362</span>  <span class="keywordtype">int</span> block_number = ReadBits(&reader, 8);</div>
|
|
<div class="line"><a name="l00363"></a><span class="lineno"> 363</span> </div>
|
|
<div class="line"><a name="l00364"></a><span class="lineno"> 364</span>  <span class="keywordflow">if</span> (section == 0) { <span class="comment">// Header.</span></div>
|
|
<div class="line"><a name="l00365"></a><span class="lineno"> 365</span>  <span class="comment">// Validate the reserved bits in the next 8 bytes.</span></div>
|
|
<div class="line"><a name="l00366"></a><span class="lineno"> 366</span>  reader.SkipBits(1);</div>
|
|
<div class="line"><a name="l00367"></a><span class="lineno"> 367</span>  RCHECK(ReadBits(&reader, 1) == 0);</div>
|
|
<div class="line"><a name="l00368"></a><span class="lineno"> 368</span>  RCHECK(ReadBits(&reader, 11) == 0x7ff);</div>
|
|
<div class="line"><a name="l00369"></a><span class="lineno"> 369</span>  reader.SkipBits(4);</div>
|
|
<div class="line"><a name="l00370"></a><span class="lineno"> 370</span>  RCHECK(ReadBits(&reader, 4) == 0xf);</div>
|
|
<div class="line"><a name="l00371"></a><span class="lineno"> 371</span>  reader.SkipBits(4);</div>
|
|
<div class="line"><a name="l00372"></a><span class="lineno"> 372</span>  RCHECK(ReadBits(&reader, 4) == 0xf);</div>
|
|
<div class="line"><a name="l00373"></a><span class="lineno"> 373</span>  reader.SkipBits(4);</div>
|
|
<div class="line"><a name="l00374"></a><span class="lineno"> 374</span>  RCHECK(ReadBits(&reader, 4) == 0xf);</div>
|
|
<div class="line"><a name="l00375"></a><span class="lineno"> 375</span>  reader.SkipBits(3);</div>
|
|
<div class="line"><a name="l00376"></a><span class="lineno"> 376</span>  RCHECK(ReadBits(&reader, 24) == 0xffffff);</div>
|
|
<div class="line"><a name="l00377"></a><span class="lineno"> 377</span>  current_sequence_number = sequence_number;</div>
|
|
<div class="line"><a name="l00378"></a><span class="lineno"> 378</span>  <span class="keywordflow">for</span> (<span class="keywordtype">size_t</span> i = 0; i < arraysize(last_block_number); ++i)</div>
|
|
<div class="line"><a name="l00379"></a><span class="lineno"> 379</span>  last_block_number[i] = -1;</div>
|
|
<div class="line"><a name="l00380"></a><span class="lineno"> 380</span>  } <span class="keywordflow">else</span> {</div>
|
|
<div class="line"><a name="l00381"></a><span class="lineno"> 381</span>  <span class="comment">// Sequence number must match (this will also fail if no header seen).</span></div>
|
|
<div class="line"><a name="l00382"></a><span class="lineno"> 382</span>  RCHECK(sequence_number == current_sequence_number);</div>
|
|
<div class="line"><a name="l00383"></a><span class="lineno"> 383</span>  <span class="comment">// Block number should be increasing.</span></div>
|
|
<div class="line"><a name="l00384"></a><span class="lineno"> 384</span>  RCHECK(block_number > last_block_number[section]);</div>
|
|
<div class="line"><a name="l00385"></a><span class="lineno"> 385</span>  last_block_number[section] = block_number;</div>
|
|
<div class="line"><a name="l00386"></a><span class="lineno"> 386</span>  }</div>
|
|
<div class="line"><a name="l00387"></a><span class="lineno"> 387</span> </div>
|
|
<div class="line"><a name="l00388"></a><span class="lineno"> 388</span>  <span class="comment">// Move to next block.</span></div>
|
|
<div class="line"><a name="l00389"></a><span class="lineno"> 389</span>  offset += 80;</div>
|
|
<div class="line"><a name="l00390"></a><span class="lineno"> 390</span>  }</div>
|
|
<div class="line"><a name="l00391"></a><span class="lineno"> 391</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00392"></a><span class="lineno"> 392</span> }</div>
|
|
<div class="line"><a name="l00393"></a><span class="lineno"> 393</span> </div>
|
|
<div class="line"><a name="l00394"></a><span class="lineno"> 394</span> </div>
|
|
<div class="line"><a name="l00395"></a><span class="lineno"> 395</span> <span class="comment">// Checks for a GSM container.</span></div>
|
|
<div class="line"><a name="l00396"></a><span class="lineno"> 396</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckGsm(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00397"></a><span class="lineno"> 397</span>  <span class="comment">// Reference: ETSI EN 300 961 V8.1.1</span></div>
|
|
<div class="line"><a name="l00398"></a><span class="lineno"> 398</span>  <span class="comment">// (http://www.etsi.org/deliver/etsi_en/300900_300999/300961/08.01.01_60/en_300961v080101p.pdf)</span></div>
|
|
<div class="line"><a name="l00399"></a><span class="lineno"> 399</span>  <span class="comment">// also http://tools.ietf.org/html/rfc3551#page-24</span></div>
|
|
<div class="line"><a name="l00400"></a><span class="lineno"> 400</span>  <span class="comment">// GSM files have a 33 byte block, only first 4 bits are fixed.</span></div>
|
|
<div class="line"><a name="l00401"></a><span class="lineno"> 401</span>  RCHECK(buffer_size >= 1024); <span class="comment">// Need enough data to do a decent check.</span></div>
|
|
<div class="line"><a name="l00402"></a><span class="lineno"> 402</span> </div>
|
|
<div class="line"><a name="l00403"></a><span class="lineno"> 403</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l00404"></a><span class="lineno"> 404</span>  <span class="keywordflow">while</span> (offset < buffer_size) {</div>
|
|
<div class="line"><a name="l00405"></a><span class="lineno"> 405</span>  <span class="comment">// First 4 bits of each block are xD.</span></div>
|
|
<div class="line"><a name="l00406"></a><span class="lineno"> 406</span>  RCHECK((buffer[offset] & 0xf0) == 0xd0);</div>
|
|
<div class="line"><a name="l00407"></a><span class="lineno"> 407</span>  offset += 33;</div>
|
|
<div class="line"><a name="l00408"></a><span class="lineno"> 408</span>  }</div>
|
|
<div class="line"><a name="l00409"></a><span class="lineno"> 409</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00410"></a><span class="lineno"> 410</span> }</div>
|
|
<div class="line"><a name="l00411"></a><span class="lineno"> 411</span> </div>
|
|
<div class="line"><a name="l00412"></a><span class="lineno"> 412</span> <span class="comment">// Advance to the first set of |num_bits| bits that match |start_code|. |offset|</span></div>
|
|
<div class="line"><a name="l00413"></a><span class="lineno"> 413</span> <span class="comment">// is the current location in the buffer, and is updated. |bytes_needed| is the</span></div>
|
|
<div class="line"><a name="l00414"></a><span class="lineno"> 414</span> <span class="comment">// number of bytes that must remain in the buffer when |start_code| is found.</span></div>
|
|
<div class="line"><a name="l00415"></a><span class="lineno"> 415</span> <span class="comment">// Returns true if start_code found (and enough space in the buffer after it),</span></div>
|
|
<div class="line"><a name="l00416"></a><span class="lineno"> 416</span> <span class="comment">// false otherwise.</span></div>
|
|
<div class="line"><a name="l00417"></a><span class="lineno"> 417</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> AdvanceToStartCode(<span class="keyword">const</span> uint8_t* buffer,</div>
|
|
<div class="line"><a name="l00418"></a><span class="lineno"> 418</span>  <span class="keywordtype">int</span> buffer_size,</div>
|
|
<div class="line"><a name="l00419"></a><span class="lineno"> 419</span>  <span class="keywordtype">int</span>* offset,</div>
|
|
<div class="line"><a name="l00420"></a><span class="lineno"> 420</span>  <span class="keywordtype">int</span> bytes_needed,</div>
|
|
<div class="line"><a name="l00421"></a><span class="lineno"> 421</span>  <span class="keywordtype">int</span> num_bits,</div>
|
|
<div class="line"><a name="l00422"></a><span class="lineno"> 422</span>  uint32_t start_code) {</div>
|
|
<div class="line"><a name="l00423"></a><span class="lineno"> 423</span>  DCHECK_GE(bytes_needed, 3);</div>
|
|
<div class="line"><a name="l00424"></a><span class="lineno"> 424</span>  DCHECK_LE(num_bits, 24); <span class="comment">// Only supports up to 24 bits.</span></div>
|
|
<div class="line"><a name="l00425"></a><span class="lineno"> 425</span> </div>
|
|
<div class="line"><a name="l00426"></a><span class="lineno"> 426</span>  <span class="comment">// Create a mask to isolate |num_bits| bits, once shifted over.</span></div>
|
|
<div class="line"><a name="l00427"></a><span class="lineno"> 427</span>  uint32_t bits_to_shift = 24 - num_bits;</div>
|
|
<div class="line"><a name="l00428"></a><span class="lineno"> 428</span>  uint32_t mask = (1 << num_bits) - 1;</div>
|
|
<div class="line"><a name="l00429"></a><span class="lineno"> 429</span>  <span class="keywordflow">while</span> (*offset + bytes_needed < buffer_size) {</div>
|
|
<div class="line"><a name="l00430"></a><span class="lineno"> 430</span>  uint32_t next = Read24(buffer + *offset);</div>
|
|
<div class="line"><a name="l00431"></a><span class="lineno"> 431</span>  <span class="keywordflow">if</span> (((next >> bits_to_shift) & mask) == start_code)</div>
|
|
<div class="line"><a name="l00432"></a><span class="lineno"> 432</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00433"></a><span class="lineno"> 433</span>  ++(*offset);</div>
|
|
<div class="line"><a name="l00434"></a><span class="lineno"> 434</span>  }</div>
|
|
<div class="line"><a name="l00435"></a><span class="lineno"> 435</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l00436"></a><span class="lineno"> 436</span> }</div>
|
|
<div class="line"><a name="l00437"></a><span class="lineno"> 437</span> </div>
|
|
<div class="line"><a name="l00438"></a><span class="lineno"> 438</span> <span class="comment">// Checks for an H.261 container.</span></div>
|
|
<div class="line"><a name="l00439"></a><span class="lineno"> 439</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckH261(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00440"></a><span class="lineno"> 440</span>  <span class="comment">// Reference: ITU-T Recommendation H.261 (03/1993)</span></div>
|
|
<div class="line"><a name="l00441"></a><span class="lineno"> 441</span>  <span class="comment">// (http://www.itu.int/rec/T-REC-H.261-199303-I/en)</span></div>
|
|
<div class="line"><a name="l00442"></a><span class="lineno"> 442</span>  RCHECK(buffer_size > 16);</div>
|
|
<div class="line"><a name="l00443"></a><span class="lineno"> 443</span> </div>
|
|
<div class="line"><a name="l00444"></a><span class="lineno"> 444</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l00445"></a><span class="lineno"> 445</span>  <span class="keywordtype">bool</span> seen_start_code = <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l00446"></a><span class="lineno"> 446</span>  <span class="keywordflow">while</span> (<span class="keyword">true</span>) {</div>
|
|
<div class="line"><a name="l00447"></a><span class="lineno"> 447</span>  <span class="comment">// Advance to picture_start_code, if there is one.</span></div>
|
|
<div class="line"><a name="l00448"></a><span class="lineno"> 448</span>  <span class="keywordflow">if</span> (!AdvanceToStartCode(buffer, buffer_size, &offset, 4, 20, 0x10)) {</div>
|
|
<div class="line"><a name="l00449"></a><span class="lineno"> 449</span>  <span class="comment">// No start code found (or off end of buffer), so success if</span></div>
|
|
<div class="line"><a name="l00450"></a><span class="lineno"> 450</span>  <span class="comment">// there was at least one valid header.</span></div>
|
|
<div class="line"><a name="l00451"></a><span class="lineno"> 451</span>  <span class="keywordflow">return</span> seen_start_code;</div>
|
|
<div class="line"><a name="l00452"></a><span class="lineno"> 452</span>  }</div>
|
|
<div class="line"><a name="l00453"></a><span class="lineno"> 453</span> </div>
|
|
<div class="line"><a name="l00454"></a><span class="lineno"> 454</span>  <span class="comment">// Now verify the block. AdvanceToStartCode() made sure that there are</span></div>
|
|
<div class="line"><a name="l00455"></a><span class="lineno"> 455</span>  <span class="comment">// at least 4 bytes remaining in the buffer.</span></div>
|
|
<div class="line"><a name="l00456"></a><span class="lineno"> 456</span>  BitReader reader(buffer + offset, buffer_size - offset);</div>
|
|
<div class="line"><a name="l00457"></a><span class="lineno"> 457</span>  RCHECK(ReadBits(&reader, 20) == 0x10);</div>
|
|
<div class="line"><a name="l00458"></a><span class="lineno"> 458</span> </div>
|
|
<div class="line"><a name="l00459"></a><span class="lineno"> 459</span>  <span class="comment">// Skip the temporal reference and PTYPE.</span></div>
|
|
<div class="line"><a name="l00460"></a><span class="lineno"> 460</span>  reader.SkipBits(5 + 6);</div>
|
|
<div class="line"><a name="l00461"></a><span class="lineno"> 461</span> </div>
|
|
<div class="line"><a name="l00462"></a><span class="lineno"> 462</span>  <span class="comment">// Skip any extra insertion information. Since this is open-ended, if we run</span></div>
|
|
<div class="line"><a name="l00463"></a><span class="lineno"> 463</span>  <span class="comment">// out of bits assume that the buffer is correctly formatted.</span></div>
|
|
<div class="line"><a name="l00464"></a><span class="lineno"> 464</span>  <span class="keywordtype">int</span> extra = ReadBits(&reader, 1);</div>
|
|
<div class="line"><a name="l00465"></a><span class="lineno"> 465</span>  <span class="keywordflow">while</span> (extra == 1) {</div>
|
|
<div class="line"><a name="l00466"></a><span class="lineno"> 466</span>  <span class="keywordflow">if</span> (!reader.SkipBits(8))</div>
|
|
<div class="line"><a name="l00467"></a><span class="lineno"> 467</span>  <span class="keywordflow">return</span> seen_start_code;</div>
|
|
<div class="line"><a name="l00468"></a><span class="lineno"> 468</span>  <span class="keywordflow">if</span> (!reader.ReadBits(1, &extra))</div>
|
|
<div class="line"><a name="l00469"></a><span class="lineno"> 469</span>  <span class="keywordflow">return</span> seen_start_code;</div>
|
|
<div class="line"><a name="l00470"></a><span class="lineno"> 470</span>  }</div>
|
|
<div class="line"><a name="l00471"></a><span class="lineno"> 471</span> </div>
|
|
<div class="line"><a name="l00472"></a><span class="lineno"> 472</span>  <span class="comment">// Next should be a Group of Blocks start code. Again, if we run out of</span></div>
|
|
<div class="line"><a name="l00473"></a><span class="lineno"> 473</span>  <span class="comment">// bits, then assume that the buffer up to here is correct, and the buffer</span></div>
|
|
<div class="line"><a name="l00474"></a><span class="lineno"> 474</span>  <span class="comment">// just happened to end in the middle of a header.</span></div>
|
|
<div class="line"><a name="l00475"></a><span class="lineno"> 475</span>  <span class="keywordtype">int</span> next;</div>
|
|
<div class="line"><a name="l00476"></a><span class="lineno"> 476</span>  <span class="keywordflow">if</span> (!reader.ReadBits(16, &next))</div>
|
|
<div class="line"><a name="l00477"></a><span class="lineno"> 477</span>  <span class="keywordflow">return</span> seen_start_code;</div>
|
|
<div class="line"><a name="l00478"></a><span class="lineno"> 478</span>  RCHECK(next == 1);</div>
|
|
<div class="line"><a name="l00479"></a><span class="lineno"> 479</span> </div>
|
|
<div class="line"><a name="l00480"></a><span class="lineno"> 480</span>  <span class="comment">// Move to the next block.</span></div>
|
|
<div class="line"><a name="l00481"></a><span class="lineno"> 481</span>  seen_start_code = <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00482"></a><span class="lineno"> 482</span>  offset += 4;</div>
|
|
<div class="line"><a name="l00483"></a><span class="lineno"> 483</span>  }</div>
|
|
<div class="line"><a name="l00484"></a><span class="lineno"> 484</span> }</div>
|
|
<div class="line"><a name="l00485"></a><span class="lineno"> 485</span> </div>
|
|
<div class="line"><a name="l00486"></a><span class="lineno"> 486</span> <span class="comment">// Checks for an H.263 container.</span></div>
|
|
<div class="line"><a name="l00487"></a><span class="lineno"> 487</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckH263(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00488"></a><span class="lineno"> 488</span>  <span class="comment">// Reference: ITU-T Recommendation H.263 (01/2005)</span></div>
|
|
<div class="line"><a name="l00489"></a><span class="lineno"> 489</span>  <span class="comment">// (http://www.itu.int/rec/T-REC-H.263-200501-I/en)</span></div>
|
|
<div class="line"><a name="l00490"></a><span class="lineno"> 490</span>  <span class="comment">// header is PSC(22b) + TR(8b) + PTYPE(8+b).</span></div>
|
|
<div class="line"><a name="l00491"></a><span class="lineno"> 491</span>  RCHECK(buffer_size > 16);</div>
|
|
<div class="line"><a name="l00492"></a><span class="lineno"> 492</span> </div>
|
|
<div class="line"><a name="l00493"></a><span class="lineno"> 493</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l00494"></a><span class="lineno"> 494</span>  <span class="keywordtype">bool</span> seen_start_code = <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l00495"></a><span class="lineno"> 495</span>  <span class="keywordflow">while</span> (<span class="keyword">true</span>) {</div>
|
|
<div class="line"><a name="l00496"></a><span class="lineno"> 496</span>  <span class="comment">// Advance to picture_start_code, if there is one.</span></div>
|
|
<div class="line"><a name="l00497"></a><span class="lineno"> 497</span>  <span class="keywordflow">if</span> (!AdvanceToStartCode(buffer, buffer_size, &offset, 9, 22, 0x20)) {</div>
|
|
<div class="line"><a name="l00498"></a><span class="lineno"> 498</span>  <span class="comment">// No start code found (or off end of buffer), so success if</span></div>
|
|
<div class="line"><a name="l00499"></a><span class="lineno"> 499</span>  <span class="comment">// there was at least one valid header.</span></div>
|
|
<div class="line"><a name="l00500"></a><span class="lineno"> 500</span>  <span class="keywordflow">return</span> seen_start_code;</div>
|
|
<div class="line"><a name="l00501"></a><span class="lineno"> 501</span>  }</div>
|
|
<div class="line"><a name="l00502"></a><span class="lineno"> 502</span> </div>
|
|
<div class="line"><a name="l00503"></a><span class="lineno"> 503</span>  <span class="comment">// Now verify the block. AdvanceToStartCode() made sure that there are</span></div>
|
|
<div class="line"><a name="l00504"></a><span class="lineno"> 504</span>  <span class="comment">// at least 9 bytes remaining in the buffer.</span></div>
|
|
<div class="line"><a name="l00505"></a><span class="lineno"> 505</span>  BitReader reader(buffer + offset, 9);</div>
|
|
<div class="line"><a name="l00506"></a><span class="lineno"> 506</span>  RCHECK(ReadBits(&reader, 22) == 0x20);</div>
|
|
<div class="line"><a name="l00507"></a><span class="lineno"> 507</span> </div>
|
|
<div class="line"><a name="l00508"></a><span class="lineno"> 508</span>  <span class="comment">// Skip the temporal reference.</span></div>
|
|
<div class="line"><a name="l00509"></a><span class="lineno"> 509</span>  reader.SkipBits(8);</div>
|
|
<div class="line"><a name="l00510"></a><span class="lineno"> 510</span> </div>
|
|
<div class="line"><a name="l00511"></a><span class="lineno"> 511</span>  <span class="comment">// Verify that the first 2 bits of PTYPE are 10b.</span></div>
|
|
<div class="line"><a name="l00512"></a><span class="lineno"> 512</span>  RCHECK(ReadBits(&reader, 2) == 2);</div>
|
|
<div class="line"><a name="l00513"></a><span class="lineno"> 513</span> </div>
|
|
<div class="line"><a name="l00514"></a><span class="lineno"> 514</span>  <span class="comment">// Skip the split screen indicator, document camera indicator, and full</span></div>
|
|
<div class="line"><a name="l00515"></a><span class="lineno"> 515</span>  <span class="comment">// picture freeze release.</span></div>
|
|
<div class="line"><a name="l00516"></a><span class="lineno"> 516</span>  reader.SkipBits(1 + 1 + 1);</div>
|
|
<div class="line"><a name="l00517"></a><span class="lineno"> 517</span> </div>
|
|
<div class="line"><a name="l00518"></a><span class="lineno"> 518</span>  <span class="comment">// Verify Source Format.</span></div>
|
|
<div class="line"><a name="l00519"></a><span class="lineno"> 519</span>  <span class="keywordtype">int</span> format = ReadBits(&reader, 3);</div>
|
|
<div class="line"><a name="l00520"></a><span class="lineno"> 520</span>  RCHECK(format != 0 && format != 6); <span class="comment">// Forbidden or reserved.</span></div>
|
|
<div class="line"><a name="l00521"></a><span class="lineno"> 521</span> </div>
|
|
<div class="line"><a name="l00522"></a><span class="lineno"> 522</span>  <span class="keywordflow">if</span> (format == 7) {</div>
|
|
<div class="line"><a name="l00523"></a><span class="lineno"> 523</span>  <span class="comment">// Verify full extended PTYPE.</span></div>
|
|
<div class="line"><a name="l00524"></a><span class="lineno"> 524</span>  <span class="keywordtype">int</span> ufep = ReadBits(&reader, 3);</div>
|
|
<div class="line"><a name="l00525"></a><span class="lineno"> 525</span>  <span class="keywordflow">if</span> (ufep == 1) {</div>
|
|
<div class="line"><a name="l00526"></a><span class="lineno"> 526</span>  <span class="comment">// Verify the optional part of PLUSPTYPE.</span></div>
|
|
<div class="line"><a name="l00527"></a><span class="lineno"> 527</span>  format = ReadBits(&reader, 3);</div>
|
|
<div class="line"><a name="l00528"></a><span class="lineno"> 528</span>  RCHECK(format != 0 && format != 7); <span class="comment">// Reserved.</span></div>
|
|
<div class="line"><a name="l00529"></a><span class="lineno"> 529</span>  reader.SkipBits(11);</div>
|
|
<div class="line"><a name="l00530"></a><span class="lineno"> 530</span>  <span class="comment">// Next 4 bits should be b1000.</span></div>
|
|
<div class="line"><a name="l00531"></a><span class="lineno"> 531</span>  RCHECK(ReadBits(&reader, 4) == 8); <span class="comment">// Not allowed.</span></div>
|
|
<div class="line"><a name="l00532"></a><span class="lineno"> 532</span>  } <span class="keywordflow">else</span> {</div>
|
|
<div class="line"><a name="l00533"></a><span class="lineno"> 533</span>  RCHECK(ufep == 0); <span class="comment">// Only 0 and 1 allowed.</span></div>
|
|
<div class="line"><a name="l00534"></a><span class="lineno"> 534</span>  }</div>
|
|
<div class="line"><a name="l00535"></a><span class="lineno"> 535</span> </div>
|
|
<div class="line"><a name="l00536"></a><span class="lineno"> 536</span>  <span class="comment">// Verify picture type code is not a reserved value.</span></div>
|
|
<div class="line"><a name="l00537"></a><span class="lineno"> 537</span>  <span class="keywordtype">int</span> picture_type_code = ReadBits(&reader, 3);</div>
|
|
<div class="line"><a name="l00538"></a><span class="lineno"> 538</span>  RCHECK(picture_type_code != 6 && picture_type_code != 7); <span class="comment">// Reserved.</span></div>
|
|
<div class="line"><a name="l00539"></a><span class="lineno"> 539</span> </div>
|
|
<div class="line"><a name="l00540"></a><span class="lineno"> 540</span>  <span class="comment">// Skip picture resampling mode, reduced resolution mode,</span></div>
|
|
<div class="line"><a name="l00541"></a><span class="lineno"> 541</span>  <span class="comment">// and rounding type.</span></div>
|
|
<div class="line"><a name="l00542"></a><span class="lineno"> 542</span>  reader.SkipBits(1 + 1 + 1);</div>
|
|
<div class="line"><a name="l00543"></a><span class="lineno"> 543</span> </div>
|
|
<div class="line"><a name="l00544"></a><span class="lineno"> 544</span>  <span class="comment">// Next 3 bits should be b001.</span></div>
|
|
<div class="line"><a name="l00545"></a><span class="lineno"> 545</span>  RCHECK(ReadBits(&reader, 3) == 1); <span class="comment">// Not allowed.</span></div>
|
|
<div class="line"><a name="l00546"></a><span class="lineno"> 546</span>  }</div>
|
|
<div class="line"><a name="l00547"></a><span class="lineno"> 547</span> </div>
|
|
<div class="line"><a name="l00548"></a><span class="lineno"> 548</span>  <span class="comment">// Move to the next block.</span></div>
|
|
<div class="line"><a name="l00549"></a><span class="lineno"> 549</span>  seen_start_code = <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00550"></a><span class="lineno"> 550</span>  offset += 9;</div>
|
|
<div class="line"><a name="l00551"></a><span class="lineno"> 551</span>  }</div>
|
|
<div class="line"><a name="l00552"></a><span class="lineno"> 552</span> }</div>
|
|
<div class="line"><a name="l00553"></a><span class="lineno"> 553</span> </div>
|
|
<div class="line"><a name="l00554"></a><span class="lineno"> 554</span> <span class="comment">// Checks for an H.264 container.</span></div>
|
|
<div class="line"><a name="l00555"></a><span class="lineno"> 555</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckH264(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00556"></a><span class="lineno"> 556</span>  <span class="comment">// Reference: ITU-T Recommendation H.264 (01/2012)</span></div>
|
|
<div class="line"><a name="l00557"></a><span class="lineno"> 557</span>  <span class="comment">// (http://www.itu.int/rec/T-REC-H.264)</span></div>
|
|
<div class="line"><a name="l00558"></a><span class="lineno"> 558</span>  <span class="comment">// Section B.1: Byte stream NAL unit syntax and semantics.</span></div>
|
|
<div class="line"><a name="l00559"></a><span class="lineno"> 559</span>  RCHECK(buffer_size > 4);</div>
|
|
<div class="line"><a name="l00560"></a><span class="lineno"> 560</span> </div>
|
|
<div class="line"><a name="l00561"></a><span class="lineno"> 561</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l00562"></a><span class="lineno"> 562</span>  <span class="keywordtype">int</span> parameter_count = 0;</div>
|
|
<div class="line"><a name="l00563"></a><span class="lineno"> 563</span>  <span class="keywordflow">while</span> (<span class="keyword">true</span>) {</div>
|
|
<div class="line"><a name="l00564"></a><span class="lineno"> 564</span>  <span class="comment">// Advance to picture_start_code, if there is one.</span></div>
|
|
<div class="line"><a name="l00565"></a><span class="lineno"> 565</span>  <span class="keywordflow">if</span> (!AdvanceToStartCode(buffer, buffer_size, &offset, 4, 24, 1)) {</div>
|
|
<div class="line"><a name="l00566"></a><span class="lineno"> 566</span>  <span class="comment">// No start code found (or off end of buffer), so success if</span></div>
|
|
<div class="line"><a name="l00567"></a><span class="lineno"> 567</span>  <span class="comment">// there was at least one valid header.</span></div>
|
|
<div class="line"><a name="l00568"></a><span class="lineno"> 568</span>  <span class="keywordflow">return</span> parameter_count > 0;</div>
|
|
<div class="line"><a name="l00569"></a><span class="lineno"> 569</span>  }</div>
|
|
<div class="line"><a name="l00570"></a><span class="lineno"> 570</span> </div>
|
|
<div class="line"><a name="l00571"></a><span class="lineno"> 571</span>  <span class="comment">// Now verify the block. AdvanceToStartCode() made sure that there are</span></div>
|
|
<div class="line"><a name="l00572"></a><span class="lineno"> 572</span>  <span class="comment">// at least 4 bytes remaining in the buffer.</span></div>
|
|
<div class="line"><a name="l00573"></a><span class="lineno"> 573</span>  BitReader reader(buffer + offset, 4);</div>
|
|
<div class="line"><a name="l00574"></a><span class="lineno"> 574</span>  RCHECK(ReadBits(&reader, 24) == 1);</div>
|
|
<div class="line"><a name="l00575"></a><span class="lineno"> 575</span> </div>
|
|
<div class="line"><a name="l00576"></a><span class="lineno"> 576</span>  <span class="comment">// Verify forbidden_zero_bit.</span></div>
|
|
<div class="line"><a name="l00577"></a><span class="lineno"> 577</span>  RCHECK(ReadBits(&reader, 1) == 0);</div>
|
|
<div class="line"><a name="l00578"></a><span class="lineno"> 578</span> </div>
|
|
<div class="line"><a name="l00579"></a><span class="lineno"> 579</span>  <span class="comment">// Extract nal_ref_idc and nal_unit_type.</span></div>
|
|
<div class="line"><a name="l00580"></a><span class="lineno"> 580</span>  <span class="keywordtype">int</span> nal_ref_idc = ReadBits(&reader, 2);</div>
|
|
<div class="line"><a name="l00581"></a><span class="lineno"> 581</span>  <span class="keywordtype">int</span> nal_unit_type = ReadBits(&reader, 5);</div>
|
|
<div class="line"><a name="l00582"></a><span class="lineno"> 582</span> </div>
|
|
<div class="line"><a name="l00583"></a><span class="lineno"> 583</span>  <span class="keywordflow">switch</span> (nal_unit_type) {</div>
|
|
<div class="line"><a name="l00584"></a><span class="lineno"> 584</span>  <span class="keywordflow">case</span> 5: <span class="comment">// Coded slice of an IDR picture.</span></div>
|
|
<div class="line"><a name="l00585"></a><span class="lineno"> 585</span>  RCHECK(nal_ref_idc != 0);</div>
|
|
<div class="line"><a name="l00586"></a><span class="lineno"> 586</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l00587"></a><span class="lineno"> 587</span>  <span class="keywordflow">case</span> 6: <span class="comment">// Supplemental enhancement information (SEI).</span></div>
|
|
<div class="line"><a name="l00588"></a><span class="lineno"> 588</span>  <span class="keywordflow">case</span> 9: <span class="comment">// Access unit delimiter.</span></div>
|
|
<div class="line"><a name="l00589"></a><span class="lineno"> 589</span>  <span class="keywordflow">case</span> 10: <span class="comment">// End of sequence.</span></div>
|
|
<div class="line"><a name="l00590"></a><span class="lineno"> 590</span>  <span class="keywordflow">case</span> 11: <span class="comment">// End of stream.</span></div>
|
|
<div class="line"><a name="l00591"></a><span class="lineno"> 591</span>  <span class="keywordflow">case</span> 12: <span class="comment">// Filler data.</span></div>
|
|
<div class="line"><a name="l00592"></a><span class="lineno"> 592</span>  RCHECK(nal_ref_idc == 0);</div>
|
|
<div class="line"><a name="l00593"></a><span class="lineno"> 593</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l00594"></a><span class="lineno"> 594</span>  <span class="keywordflow">case</span> 7: <span class="comment">// Sequence parameter set.</span></div>
|
|
<div class="line"><a name="l00595"></a><span class="lineno"> 595</span>  <span class="keywordflow">case</span> 8: <span class="comment">// Picture parameter set.</span></div>
|
|
<div class="line"><a name="l00596"></a><span class="lineno"> 596</span>  ++parameter_count;</div>
|
|
<div class="line"><a name="l00597"></a><span class="lineno"> 597</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l00598"></a><span class="lineno"> 598</span>  }</div>
|
|
<div class="line"><a name="l00599"></a><span class="lineno"> 599</span> </div>
|
|
<div class="line"><a name="l00600"></a><span class="lineno"> 600</span>  <span class="comment">// Skip the current start_code_prefix and move to the next.</span></div>
|
|
<div class="line"><a name="l00601"></a><span class="lineno"> 601</span>  offset += 4;</div>
|
|
<div class="line"><a name="l00602"></a><span class="lineno"> 602</span>  }</div>
|
|
<div class="line"><a name="l00603"></a><span class="lineno"> 603</span> }</div>
|
|
<div class="line"><a name="l00604"></a><span class="lineno"> 604</span> </div>
|
|
<div class="line"><a name="l00605"></a><span class="lineno"> 605</span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">char</span> kHlsSignature[] = <span class="stringliteral">"#EXTM3U"</span>;</div>
|
|
<div class="line"><a name="l00606"></a><span class="lineno"> 606</span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">char</span> kHls1[] = <span class="stringliteral">"#EXT-X-STREAM-INF:"</span>;</div>
|
|
<div class="line"><a name="l00607"></a><span class="lineno"> 607</span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">char</span> kHls2[] = <span class="stringliteral">"#EXT-X-TARGETDURATION:"</span>;</div>
|
|
<div class="line"><a name="l00608"></a><span class="lineno"> 608</span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">char</span> kHls3[] = <span class="stringliteral">"#EXT-X-MEDIA-SEQUENCE:"</span>;</div>
|
|
<div class="line"><a name="l00609"></a><span class="lineno"> 609</span> </div>
|
|
<div class="line"><a name="l00610"></a><span class="lineno"> 610</span> <span class="comment">// Additional checks for a HLS container.</span></div>
|
|
<div class="line"><a name="l00611"></a><span class="lineno"> 611</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckHls(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00612"></a><span class="lineno"> 612</span>  <span class="comment">// HLS is simply a play list used for Apple HTTP Live Streaming.</span></div>
|
|
<div class="line"><a name="l00613"></a><span class="lineno"> 613</span>  <span class="comment">// Reference: Apple HTTP Live Streaming Overview</span></div>
|
|
<div class="line"><a name="l00614"></a><span class="lineno"> 614</span>  <span class="comment">// (http://goo.gl/MIwxj)</span></div>
|
|
<div class="line"><a name="l00615"></a><span class="lineno"> 615</span> </div>
|
|
<div class="line"><a name="l00616"></a><span class="lineno"> 616</span>  <span class="keywordflow">if</span> (StartsWith(buffer, buffer_size, kHlsSignature)) {</div>
|
|
<div class="line"><a name="l00617"></a><span class="lineno"> 617</span>  <span class="comment">// Need to find "#EXT-X-STREAM-INF:", "#EXT-X-TARGETDURATION:", or</span></div>
|
|
<div class="line"><a name="l00618"></a><span class="lineno"> 618</span>  <span class="comment">// "#EXT-X-MEDIA-SEQUENCE:" somewhere in the buffer. Other playlists (like</span></div>
|
|
<div class="line"><a name="l00619"></a><span class="lineno"> 619</span>  <span class="comment">// WinAmp) only have additional lines with #EXTINF</span></div>
|
|
<div class="line"><a name="l00620"></a><span class="lineno"> 620</span>  <span class="comment">// (http://en.wikipedia.org/wiki/M3U).</span></div>
|
|
<div class="line"><a name="l00621"></a><span class="lineno"> 621</span>  <span class="keywordtype">int</span> offset = strlen(kHlsSignature);</div>
|
|
<div class="line"><a name="l00622"></a><span class="lineno"> 622</span>  <span class="keywordflow">while</span> (offset < buffer_size) {</div>
|
|
<div class="line"><a name="l00623"></a><span class="lineno"> 623</span>  <span class="keywordflow">if</span> (buffer[offset] == <span class="charliteral">'#'</span>) {</div>
|
|
<div class="line"><a name="l00624"></a><span class="lineno"> 624</span>  <span class="keywordflow">if</span> (StartsWith(buffer + offset, buffer_size - offset, kHls1) ||</div>
|
|
<div class="line"><a name="l00625"></a><span class="lineno"> 625</span>  StartsWith(buffer + offset, buffer_size - offset, kHls2) ||</div>
|
|
<div class="line"><a name="l00626"></a><span class="lineno"> 626</span>  StartsWith(buffer + offset, buffer_size - offset, kHls3)) {</div>
|
|
<div class="line"><a name="l00627"></a><span class="lineno"> 627</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00628"></a><span class="lineno"> 628</span>  }</div>
|
|
<div class="line"><a name="l00629"></a><span class="lineno"> 629</span>  }</div>
|
|
<div class="line"><a name="l00630"></a><span class="lineno"> 630</span>  ++offset;</div>
|
|
<div class="line"><a name="l00631"></a><span class="lineno"> 631</span>  }</div>
|
|
<div class="line"><a name="l00632"></a><span class="lineno"> 632</span>  }</div>
|
|
<div class="line"><a name="l00633"></a><span class="lineno"> 633</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l00634"></a><span class="lineno"> 634</span> }</div>
|
|
<div class="line"><a name="l00635"></a><span class="lineno"> 635</span> </div>
|
|
<div class="line"><a name="l00636"></a><span class="lineno"> 636</span> <span class="comment">// Checks for a MJPEG stream.</span></div>
|
|
<div class="line"><a name="l00637"></a><span class="lineno"> 637</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckMJpeg(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00638"></a><span class="lineno"> 638</span>  <span class="comment">// Reference: ISO/IEC 10918-1 : 1993(E), Annex B</span></div>
|
|
<div class="line"><a name="l00639"></a><span class="lineno"> 639</span>  <span class="comment">// (http://www.w3.org/Graphics/JPEG/itu-t81.pdf)</span></div>
|
|
<div class="line"><a name="l00640"></a><span class="lineno"> 640</span>  RCHECK(buffer_size >= 16);</div>
|
|
<div class="line"><a name="l00641"></a><span class="lineno"> 641</span> </div>
|
|
<div class="line"><a name="l00642"></a><span class="lineno"> 642</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l00643"></a><span class="lineno"> 643</span>  <span class="keywordtype">int</span> last_restart = -1;</div>
|
|
<div class="line"><a name="l00644"></a><span class="lineno"> 644</span>  <span class="keywordtype">int</span> num_codes = 0;</div>
|
|
<div class="line"><a name="l00645"></a><span class="lineno"> 645</span>  <span class="keywordflow">while</span> (offset + 5 < buffer_size) {</div>
|
|
<div class="line"><a name="l00646"></a><span class="lineno"> 646</span>  <span class="comment">// Marker codes are always a two byte code with the first byte xFF.</span></div>
|
|
<div class="line"><a name="l00647"></a><span class="lineno"> 647</span>  RCHECK(buffer[offset] == 0xff);</div>
|
|
<div class="line"><a name="l00648"></a><span class="lineno"> 648</span>  uint8_t code = buffer[offset + 1];</div>
|
|
<div class="line"><a name="l00649"></a><span class="lineno"> 649</span>  RCHECK(code >= 0xc0 || code == 1);</div>
|
|
<div class="line"><a name="l00650"></a><span class="lineno"> 650</span> </div>
|
|
<div class="line"><a name="l00651"></a><span class="lineno"> 651</span>  <span class="comment">// Skip sequences of xFF.</span></div>
|
|
<div class="line"><a name="l00652"></a><span class="lineno"> 652</span>  <span class="keywordflow">if</span> (code == 0xff) {</div>
|
|
<div class="line"><a name="l00653"></a><span class="lineno"> 653</span>  ++offset;</div>
|
|
<div class="line"><a name="l00654"></a><span class="lineno"> 654</span>  <span class="keywordflow">continue</span>;</div>
|
|
<div class="line"><a name="l00655"></a><span class="lineno"> 655</span>  }</div>
|
|
<div class="line"><a name="l00656"></a><span class="lineno"> 656</span> </div>
|
|
<div class="line"><a name="l00657"></a><span class="lineno"> 657</span>  <span class="comment">// Success if the next marker code is EOI (end of image)</span></div>
|
|
<div class="line"><a name="l00658"></a><span class="lineno"> 658</span>  <span class="keywordflow">if</span> (code == 0xd9)</div>
|
|
<div class="line"><a name="l00659"></a><span class="lineno"> 659</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00660"></a><span class="lineno"> 660</span> </div>
|
|
<div class="line"><a name="l00661"></a><span class="lineno"> 661</span>  <span class="comment">// Check remaining codes.</span></div>
|
|
<div class="line"><a name="l00662"></a><span class="lineno"> 662</span>  <span class="keywordflow">if</span> (code == 0xd8 || code == 1) {</div>
|
|
<div class="line"><a name="l00663"></a><span class="lineno"> 663</span>  <span class="comment">// SOI (start of image) / TEM (private use). No other data with header.</span></div>
|
|
<div class="line"><a name="l00664"></a><span class="lineno"> 664</span>  offset += 2;</div>
|
|
<div class="line"><a name="l00665"></a><span class="lineno"> 665</span>  } <span class="keywordflow">else</span> <span class="keywordflow">if</span> (code >= 0xd0 && code <= 0xd7) {</div>
|
|
<div class="line"><a name="l00666"></a><span class="lineno"> 666</span>  <span class="comment">// RST (restart) codes must be in sequence. No other data with header.</span></div>
|
|
<div class="line"><a name="l00667"></a><span class="lineno"> 667</span>  <span class="keywordtype">int</span> restart = code & 0x07;</div>
|
|
<div class="line"><a name="l00668"></a><span class="lineno"> 668</span>  <span class="keywordflow">if</span> (last_restart >= 0)</div>
|
|
<div class="line"><a name="l00669"></a><span class="lineno"> 669</span>  RCHECK(restart == (last_restart + 1) % 8);</div>
|
|
<div class="line"><a name="l00670"></a><span class="lineno"> 670</span>  last_restart = restart;</div>
|
|
<div class="line"><a name="l00671"></a><span class="lineno"> 671</span>  offset += 2;</div>
|
|
<div class="line"><a name="l00672"></a><span class="lineno"> 672</span>  } <span class="keywordflow">else</span> {</div>
|
|
<div class="line"><a name="l00673"></a><span class="lineno"> 673</span>  <span class="comment">// All remaining marker codes are followed by a length of the header.</span></div>
|
|
<div class="line"><a name="l00674"></a><span class="lineno"> 674</span>  <span class="keywordtype">int</span> length = Read16(buffer + offset + 2) + 2;</div>
|
|
<div class="line"><a name="l00675"></a><span class="lineno"> 675</span> </div>
|
|
<div class="line"><a name="l00676"></a><span class="lineno"> 676</span>  <span class="comment">// Special handling of SOS (start of scan) marker since the entropy</span></div>
|
|
<div class="line"><a name="l00677"></a><span class="lineno"> 677</span>  <span class="comment">// coded data follows the SOS. Any xFF byte in the data block must be</span></div>
|
|
<div class="line"><a name="l00678"></a><span class="lineno"> 678</span>  <span class="comment">// followed by x00 in the data.</span></div>
|
|
<div class="line"><a name="l00679"></a><span class="lineno"> 679</span>  <span class="keywordflow">if</span> (code == 0xda) {</div>
|
|
<div class="line"><a name="l00680"></a><span class="lineno"> 680</span>  <span class="keywordtype">int</span> number_components = buffer[offset + 4];</div>
|
|
<div class="line"><a name="l00681"></a><span class="lineno"> 681</span>  RCHECK(length == 8 + 2 * number_components);</div>
|
|
<div class="line"><a name="l00682"></a><span class="lineno"> 682</span> </div>
|
|
<div class="line"><a name="l00683"></a><span class="lineno"> 683</span>  <span class="comment">// Advance to the next marker.</span></div>
|
|
<div class="line"><a name="l00684"></a><span class="lineno"> 684</span>  offset += length;</div>
|
|
<div class="line"><a name="l00685"></a><span class="lineno"> 685</span>  <span class="keywordflow">while</span> (offset + 2 < buffer_size) {</div>
|
|
<div class="line"><a name="l00686"></a><span class="lineno"> 686</span>  <span class="keywordflow">if</span> (buffer[offset] == 0xff && buffer[offset + 1] != 0)</div>
|
|
<div class="line"><a name="l00687"></a><span class="lineno"> 687</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l00688"></a><span class="lineno"> 688</span>  ++offset;</div>
|
|
<div class="line"><a name="l00689"></a><span class="lineno"> 689</span>  }</div>
|
|
<div class="line"><a name="l00690"></a><span class="lineno"> 690</span>  } <span class="keywordflow">else</span> {</div>
|
|
<div class="line"><a name="l00691"></a><span class="lineno"> 691</span>  <span class="comment">// Skip over the marker data for the other marker codes.</span></div>
|
|
<div class="line"><a name="l00692"></a><span class="lineno"> 692</span>  offset += length;</div>
|
|
<div class="line"><a name="l00693"></a><span class="lineno"> 693</span>  }</div>
|
|
<div class="line"><a name="l00694"></a><span class="lineno"> 694</span>  }</div>
|
|
<div class="line"><a name="l00695"></a><span class="lineno"> 695</span>  ++num_codes;</div>
|
|
<div class="line"><a name="l00696"></a><span class="lineno"> 696</span>  }</div>
|
|
<div class="line"><a name="l00697"></a><span class="lineno"> 697</span>  <span class="keywordflow">return</span> (num_codes > 1);</div>
|
|
<div class="line"><a name="l00698"></a><span class="lineno"> 698</span> }</div>
|
|
<div class="line"><a name="l00699"></a><span class="lineno"> 699</span> </div>
|
|
<div class="line"><a name="l00700"></a><span class="lineno"> 700</span> <span class="keyword">enum</span> Mpeg2StartCodes {</div>
|
|
<div class="line"><a name="l00701"></a><span class="lineno"> 701</span>  PROGRAM_END_CODE = 0xb9,</div>
|
|
<div class="line"><a name="l00702"></a><span class="lineno"> 702</span>  PACK_START_CODE = 0xba</div>
|
|
<div class="line"><a name="l00703"></a><span class="lineno"> 703</span> };</div>
|
|
<div class="line"><a name="l00704"></a><span class="lineno"> 704</span> </div>
|
|
<div class="line"><a name="l00705"></a><span class="lineno"> 705</span> <span class="comment">// Checks for a MPEG2 Program Stream.</span></div>
|
|
<div class="line"><a name="l00706"></a><span class="lineno"> 706</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckMpeg2ProgramStream(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00707"></a><span class="lineno"> 707</span>  <span class="comment">// Reference: ISO/IEC 13818-1 : 2000 (E) / ITU-T Rec. H.222.0 (2000 E).</span></div>
|
|
<div class="line"><a name="l00708"></a><span class="lineno"> 708</span>  RCHECK(buffer_size > 14);</div>
|
|
<div class="line"><a name="l00709"></a><span class="lineno"> 709</span> </div>
|
|
<div class="line"><a name="l00710"></a><span class="lineno"> 710</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l00711"></a><span class="lineno"> 711</span>  <span class="keywordflow">while</span> (offset + 14 < buffer_size) {</div>
|
|
<div class="line"><a name="l00712"></a><span class="lineno"> 712</span>  BitReader reader(buffer + offset, 14);</div>
|
|
<div class="line"><a name="l00713"></a><span class="lineno"> 713</span> </div>
|
|
<div class="line"><a name="l00714"></a><span class="lineno"> 714</span>  <span class="comment">// Must start with pack_start_code.</span></div>
|
|
<div class="line"><a name="l00715"></a><span class="lineno"> 715</span>  RCHECK(ReadBits(&reader, 24) == 1);</div>
|
|
<div class="line"><a name="l00716"></a><span class="lineno"> 716</span>  RCHECK(ReadBits(&reader, 8) == PACK_START_CODE);</div>
|
|
<div class="line"><a name="l00717"></a><span class="lineno"> 717</span> </div>
|
|
<div class="line"><a name="l00718"></a><span class="lineno"> 718</span>  <span class="comment">// Determine MPEG version (MPEG1 has b0010, while MPEG2 has b01).</span></div>
|
|
<div class="line"><a name="l00719"></a><span class="lineno"> 719</span>  <span class="keywordtype">int</span> mpeg_version = ReadBits(&reader, 2);</div>
|
|
<div class="line"><a name="l00720"></a><span class="lineno"> 720</span>  <span class="keywordflow">if</span> (mpeg_version == 0) {</div>
|
|
<div class="line"><a name="l00721"></a><span class="lineno"> 721</span>  <span class="comment">// MPEG1, 10 byte header</span></div>
|
|
<div class="line"><a name="l00722"></a><span class="lineno"> 722</span>  <span class="comment">// Validate rest of version code</span></div>
|
|
<div class="line"><a name="l00723"></a><span class="lineno"> 723</span>  RCHECK(ReadBits(&reader, 2) == 2);</div>
|
|
<div class="line"><a name="l00724"></a><span class="lineno"> 724</span>  } <span class="keywordflow">else</span> {</div>
|
|
<div class="line"><a name="l00725"></a><span class="lineno"> 725</span>  RCHECK(mpeg_version == 1);</div>
|
|
<div class="line"><a name="l00726"></a><span class="lineno"> 726</span>  }</div>
|
|
<div class="line"><a name="l00727"></a><span class="lineno"> 727</span> </div>
|
|
<div class="line"><a name="l00728"></a><span class="lineno"> 728</span>  <span class="comment">// Skip system_clock_reference_base [32..30].</span></div>
|
|
<div class="line"><a name="l00729"></a><span class="lineno"> 729</span>  reader.SkipBits(3);</div>
|
|
<div class="line"><a name="l00730"></a><span class="lineno"> 730</span> </div>
|
|
<div class="line"><a name="l00731"></a><span class="lineno"> 731</span>  <span class="comment">// Verify marker bit.</span></div>
|
|
<div class="line"><a name="l00732"></a><span class="lineno"> 732</span>  RCHECK(ReadBits(&reader, 1) == 1);</div>
|
|
<div class="line"><a name="l00733"></a><span class="lineno"> 733</span> </div>
|
|
<div class="line"><a name="l00734"></a><span class="lineno"> 734</span>  <span class="comment">// Skip system_clock_reference_base [29..15].</span></div>
|
|
<div class="line"><a name="l00735"></a><span class="lineno"> 735</span>  reader.SkipBits(15);</div>
|
|
<div class="line"><a name="l00736"></a><span class="lineno"> 736</span> </div>
|
|
<div class="line"><a name="l00737"></a><span class="lineno"> 737</span>  <span class="comment">// Verify next marker bit.</span></div>
|
|
<div class="line"><a name="l00738"></a><span class="lineno"> 738</span>  RCHECK(ReadBits(&reader, 1) == 1);</div>
|
|
<div class="line"><a name="l00739"></a><span class="lineno"> 739</span> </div>
|
|
<div class="line"><a name="l00740"></a><span class="lineno"> 740</span>  <span class="comment">// Skip system_clock_reference_base [14..0].</span></div>
|
|
<div class="line"><a name="l00741"></a><span class="lineno"> 741</span>  reader.SkipBits(15);</div>
|
|
<div class="line"><a name="l00742"></a><span class="lineno"> 742</span> </div>
|
|
<div class="line"><a name="l00743"></a><span class="lineno"> 743</span>  <span class="comment">// Verify next marker bit.</span></div>
|
|
<div class="line"><a name="l00744"></a><span class="lineno"> 744</span>  RCHECK(ReadBits(&reader, 1) == 1);</div>
|
|
<div class="line"><a name="l00745"></a><span class="lineno"> 745</span> </div>
|
|
<div class="line"><a name="l00746"></a><span class="lineno"> 746</span>  <span class="keywordflow">if</span> (mpeg_version == 0) {</div>
|
|
<div class="line"><a name="l00747"></a><span class="lineno"> 747</span>  <span class="comment">// Verify second marker bit.</span></div>
|
|
<div class="line"><a name="l00748"></a><span class="lineno"> 748</span>  RCHECK(ReadBits(&reader, 1) == 1);</div>
|
|
<div class="line"><a name="l00749"></a><span class="lineno"> 749</span> </div>
|
|
<div class="line"><a name="l00750"></a><span class="lineno"> 750</span>  <span class="comment">// Skip mux_rate.</span></div>
|
|
<div class="line"><a name="l00751"></a><span class="lineno"> 751</span>  reader.SkipBits(22);</div>
|
|
<div class="line"><a name="l00752"></a><span class="lineno"> 752</span> </div>
|
|
<div class="line"><a name="l00753"></a><span class="lineno"> 753</span>  <span class="comment">// Verify next marker bit.</span></div>
|
|
<div class="line"><a name="l00754"></a><span class="lineno"> 754</span>  RCHECK(ReadBits(&reader, 1) == 1);</div>
|
|
<div class="line"><a name="l00755"></a><span class="lineno"> 755</span> </div>
|
|
<div class="line"><a name="l00756"></a><span class="lineno"> 756</span>  <span class="comment">// Update offset to be after this header.</span></div>
|
|
<div class="line"><a name="l00757"></a><span class="lineno"> 757</span>  offset += 12;</div>
|
|
<div class="line"><a name="l00758"></a><span class="lineno"> 758</span>  } <span class="keywordflow">else</span> {</div>
|
|
<div class="line"><a name="l00759"></a><span class="lineno"> 759</span>  <span class="comment">// Must be MPEG2.</span></div>
|
|
<div class="line"><a name="l00760"></a><span class="lineno"> 760</span>  <span class="comment">// Skip program_mux_rate.</span></div>
|
|
<div class="line"><a name="l00761"></a><span class="lineno"> 761</span>  reader.SkipBits(22);</div>
|
|
<div class="line"><a name="l00762"></a><span class="lineno"> 762</span> </div>
|
|
<div class="line"><a name="l00763"></a><span class="lineno"> 763</span>  <span class="comment">// Verify pair of marker bits.</span></div>
|
|
<div class="line"><a name="l00764"></a><span class="lineno"> 764</span>  RCHECK(ReadBits(&reader, 2) == 3);</div>
|
|
<div class="line"><a name="l00765"></a><span class="lineno"> 765</span> </div>
|
|
<div class="line"><a name="l00766"></a><span class="lineno"> 766</span>  <span class="comment">// Skip reserved.</span></div>
|
|
<div class="line"><a name="l00767"></a><span class="lineno"> 767</span>  reader.SkipBits(5);</div>
|
|
<div class="line"><a name="l00768"></a><span class="lineno"> 768</span> </div>
|
|
<div class="line"><a name="l00769"></a><span class="lineno"> 769</span>  <span class="comment">// Update offset to be after this header.</span></div>
|
|
<div class="line"><a name="l00770"></a><span class="lineno"> 770</span>  <span class="keywordtype">int</span> pack_stuffing_length = ReadBits(&reader, 3);</div>
|
|
<div class="line"><a name="l00771"></a><span class="lineno"> 771</span>  offset += 14 + pack_stuffing_length;</div>
|
|
<div class="line"><a name="l00772"></a><span class="lineno"> 772</span>  }</div>
|
|
<div class="line"><a name="l00773"></a><span class="lineno"> 773</span> </div>
|
|
<div class="line"><a name="l00774"></a><span class="lineno"> 774</span>  <span class="comment">// Check for system headers and PES_packets.</span></div>
|
|
<div class="line"><a name="l00775"></a><span class="lineno"> 775</span>  <span class="keywordflow">while</span> (offset + 6 < buffer_size && Read24(buffer + offset) == 1) {</div>
|
|
<div class="line"><a name="l00776"></a><span class="lineno"> 776</span>  <span class="comment">// Next 8 bits determine stream type.</span></div>
|
|
<div class="line"><a name="l00777"></a><span class="lineno"> 777</span>  <span class="keywordtype">int</span> stream_id = buffer[offset + 3];</div>
|
|
<div class="line"><a name="l00778"></a><span class="lineno"> 778</span> </div>
|
|
<div class="line"><a name="l00779"></a><span class="lineno"> 779</span>  <span class="comment">// Some stream types are reserved and shouldn't occur.</span></div>
|
|
<div class="line"><a name="l00780"></a><span class="lineno"> 780</span>  <span class="keywordflow">if</span> (mpeg_version == 0)</div>
|
|
<div class="line"><a name="l00781"></a><span class="lineno"> 781</span>  RCHECK(stream_id != 0xbc && stream_id < 0xf0);</div>
|
|
<div class="line"><a name="l00782"></a><span class="lineno"> 782</span>  <span class="keywordflow">else</span></div>
|
|
<div class="line"><a name="l00783"></a><span class="lineno"> 783</span>  RCHECK(stream_id != 0xfc && stream_id != 0xfd && stream_id != 0xfe);</div>
|
|
<div class="line"><a name="l00784"></a><span class="lineno"> 784</span> </div>
|
|
<div class="line"><a name="l00785"></a><span class="lineno"> 785</span>  <span class="comment">// Some stream types are used for pack headers.</span></div>
|
|
<div class="line"><a name="l00786"></a><span class="lineno"> 786</span>  <span class="keywordflow">if</span> (stream_id == PACK_START_CODE) <span class="comment">// back to outer loop.</span></div>
|
|
<div class="line"><a name="l00787"></a><span class="lineno"> 787</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l00788"></a><span class="lineno"> 788</span>  <span class="keywordflow">if</span> (stream_id == PROGRAM_END_CODE) <span class="comment">// end of stream.</span></div>
|
|
<div class="line"><a name="l00789"></a><span class="lineno"> 789</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00790"></a><span class="lineno"> 790</span> </div>
|
|
<div class="line"><a name="l00791"></a><span class="lineno"> 791</span>  <span class="keywordtype">int</span> pes_length = Read16(buffer + offset + 4);</div>
|
|
<div class="line"><a name="l00792"></a><span class="lineno"> 792</span>  RCHECK(pes_length > 0);</div>
|
|
<div class="line"><a name="l00793"></a><span class="lineno"> 793</span>  offset = offset + 6 + pes_length;</div>
|
|
<div class="line"><a name="l00794"></a><span class="lineno"> 794</span>  }</div>
|
|
<div class="line"><a name="l00795"></a><span class="lineno"> 795</span>  }</div>
|
|
<div class="line"><a name="l00796"></a><span class="lineno"> 796</span>  <span class="comment">// Success as we are off the end of the buffer and liked everything</span></div>
|
|
<div class="line"><a name="l00797"></a><span class="lineno"> 797</span>  <span class="comment">// in the buffer.</span></div>
|
|
<div class="line"><a name="l00798"></a><span class="lineno"> 798</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00799"></a><span class="lineno"> 799</span> }</div>
|
|
<div class="line"><a name="l00800"></a><span class="lineno"> 800</span> </div>
|
|
<div class="line"><a name="l00801"></a><span class="lineno"> 801</span> <span class="keyword">const</span> uint8_t kMpeg2SyncWord = 0x47;</div>
|
|
<div class="line"><a name="l00802"></a><span class="lineno"> 802</span> </div>
|
|
<div class="line"><a name="l00803"></a><span class="lineno"> 803</span> <span class="comment">// Checks for a MPEG2 Transport Stream.</span></div>
|
|
<div class="line"><a name="l00804"></a><span class="lineno"> 804</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckMpeg2TransportStream(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00805"></a><span class="lineno"> 805</span>  <span class="comment">// Spec: ISO/IEC 13818-1 : 2000 (E) / ITU-T Rec. H.222.0 (2000 E).</span></div>
|
|
<div class="line"><a name="l00806"></a><span class="lineno"> 806</span>  <span class="comment">// Normal packet size is 188 bytes. However, some systems add various error</span></div>
|
|
<div class="line"><a name="l00807"></a><span class="lineno"> 807</span>  <span class="comment">// correction data at the end, resulting in packet of length 192/204/208</span></div>
|
|
<div class="line"><a name="l00808"></a><span class="lineno"> 808</span>  <span class="comment">// (https://en.wikipedia.org/wiki/MPEG_transport_stream). Determine the</span></div>
|
|
<div class="line"><a name="l00809"></a><span class="lineno"> 809</span>  <span class="comment">// length with the first packet.</span></div>
|
|
<div class="line"><a name="l00810"></a><span class="lineno"> 810</span>  RCHECK(buffer_size >= 250); <span class="comment">// Want more than 1 packet to check.</span></div>
|
|
<div class="line"><a name="l00811"></a><span class="lineno"> 811</span> </div>
|
|
<div class="line"><a name="l00812"></a><span class="lineno"> 812</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l00813"></a><span class="lineno"> 813</span>  <span class="keywordtype">int</span> packet_length = -1;</div>
|
|
<div class="line"><a name="l00814"></a><span class="lineno"> 814</span>  <span class="keywordflow">while</span> (buffer[offset] != kMpeg2SyncWord && offset < 20) {</div>
|
|
<div class="line"><a name="l00815"></a><span class="lineno"> 815</span>  <span class="comment">// Skip over any header in the first 20 bytes.</span></div>
|
|
<div class="line"><a name="l00816"></a><span class="lineno"> 816</span>  ++offset;</div>
|
|
<div class="line"><a name="l00817"></a><span class="lineno"> 817</span>  }</div>
|
|
<div class="line"><a name="l00818"></a><span class="lineno"> 818</span> </div>
|
|
<div class="line"><a name="l00819"></a><span class="lineno"> 819</span>  <span class="keywordflow">while</span> (offset + 6 < buffer_size) {</div>
|
|
<div class="line"><a name="l00820"></a><span class="lineno"> 820</span>  BitReader reader(buffer + offset, 6);</div>
|
|
<div class="line"><a name="l00821"></a><span class="lineno"> 821</span> </div>
|
|
<div class="line"><a name="l00822"></a><span class="lineno"> 822</span>  <span class="comment">// Must start with sync byte.</span></div>
|
|
<div class="line"><a name="l00823"></a><span class="lineno"> 823</span>  RCHECK(ReadBits(&reader, 8) == kMpeg2SyncWord);</div>
|
|
<div class="line"><a name="l00824"></a><span class="lineno"> 824</span> </div>
|
|
<div class="line"><a name="l00825"></a><span class="lineno"> 825</span>  <span class="comment">// Skip transport_error_indicator, payload_unit_start_indicator, and</span></div>
|
|
<div class="line"><a name="l00826"></a><span class="lineno"> 826</span>  <span class="comment">// transport_priority.</span></div>
|
|
<div class="line"><a name="l00827"></a><span class="lineno"> 827</span>  reader.SkipBits(1 + 1 + 1);</div>
|
|
<div class="line"><a name="l00828"></a><span class="lineno"> 828</span> </div>
|
|
<div class="line"><a name="l00829"></a><span class="lineno"> 829</span>  <span class="comment">// Verify the pid is not a reserved value.</span></div>
|
|
<div class="line"><a name="l00830"></a><span class="lineno"> 830</span>  <span class="keywordtype">int</span> pid = ReadBits(&reader, 13);</div>
|
|
<div class="line"><a name="l00831"></a><span class="lineno"> 831</span>  RCHECK(pid < 3 || pid > 15);</div>
|
|
<div class="line"><a name="l00832"></a><span class="lineno"> 832</span> </div>
|
|
<div class="line"><a name="l00833"></a><span class="lineno"> 833</span>  <span class="comment">// Skip transport_scrambling_control.</span></div>
|
|
<div class="line"><a name="l00834"></a><span class="lineno"> 834</span>  reader.SkipBits(2);</div>
|
|
<div class="line"><a name="l00835"></a><span class="lineno"> 835</span> </div>
|
|
<div class="line"><a name="l00836"></a><span class="lineno"> 836</span>  <span class="comment">// Adaptation_field_control can not be 0.</span></div>
|
|
<div class="line"><a name="l00837"></a><span class="lineno"> 837</span>  <span class="keywordtype">int</span> adaptation_field_control = ReadBits(&reader, 2);</div>
|
|
<div class="line"><a name="l00838"></a><span class="lineno"> 838</span>  RCHECK(adaptation_field_control != 0);</div>
|
|
<div class="line"><a name="l00839"></a><span class="lineno"> 839</span> </div>
|
|
<div class="line"><a name="l00840"></a><span class="lineno"> 840</span>  <span class="comment">// If there is an adaptation_field, verify it.</span></div>
|
|
<div class="line"><a name="l00841"></a><span class="lineno"> 841</span>  <span class="keywordflow">if</span> (adaptation_field_control >= 2) {</div>
|
|
<div class="line"><a name="l00842"></a><span class="lineno"> 842</span>  <span class="comment">// Skip continuity_counter.</span></div>
|
|
<div class="line"><a name="l00843"></a><span class="lineno"> 843</span>  reader.SkipBits(4);</div>
|
|
<div class="line"><a name="l00844"></a><span class="lineno"> 844</span> </div>
|
|
<div class="line"><a name="l00845"></a><span class="lineno"> 845</span>  <span class="comment">// Get adaptation_field_length and verify it.</span></div>
|
|
<div class="line"><a name="l00846"></a><span class="lineno"> 846</span>  <span class="keywordtype">int</span> adaptation_field_length = ReadBits(&reader, 8);</div>
|
|
<div class="line"><a name="l00847"></a><span class="lineno"> 847</span>  <span class="keywordflow">if</span> (adaptation_field_control == 2)</div>
|
|
<div class="line"><a name="l00848"></a><span class="lineno"> 848</span>  RCHECK(adaptation_field_length == 183);</div>
|
|
<div class="line"><a name="l00849"></a><span class="lineno"> 849</span>  <span class="keywordflow">else</span></div>
|
|
<div class="line"><a name="l00850"></a><span class="lineno"> 850</span>  RCHECK(adaptation_field_length <= 182);</div>
|
|
<div class="line"><a name="l00851"></a><span class="lineno"> 851</span>  }</div>
|
|
<div class="line"><a name="l00852"></a><span class="lineno"> 852</span> </div>
|
|
<div class="line"><a name="l00853"></a><span class="lineno"> 853</span>  <span class="comment">// Attempt to determine the packet length on the first packet.</span></div>
|
|
<div class="line"><a name="l00854"></a><span class="lineno"> 854</span>  <span class="keywordflow">if</span> (packet_length < 0) {</div>
|
|
<div class="line"><a name="l00855"></a><span class="lineno"> 855</span>  <span class="keywordflow">if</span> (buffer[offset + 188] == kMpeg2SyncWord)</div>
|
|
<div class="line"><a name="l00856"></a><span class="lineno"> 856</span>  packet_length = 188;</div>
|
|
<div class="line"><a name="l00857"></a><span class="lineno"> 857</span>  <span class="keywordflow">else</span> <span class="keywordflow">if</span> (buffer[offset + 192] == kMpeg2SyncWord)</div>
|
|
<div class="line"><a name="l00858"></a><span class="lineno"> 858</span>  packet_length = 192;</div>
|
|
<div class="line"><a name="l00859"></a><span class="lineno"> 859</span>  <span class="keywordflow">else</span> <span class="keywordflow">if</span> (buffer[offset + 204] == kMpeg2SyncWord)</div>
|
|
<div class="line"><a name="l00860"></a><span class="lineno"> 860</span>  packet_length = 204;</div>
|
|
<div class="line"><a name="l00861"></a><span class="lineno"> 861</span>  <span class="keywordflow">else</span></div>
|
|
<div class="line"><a name="l00862"></a><span class="lineno"> 862</span>  packet_length = 208;</div>
|
|
<div class="line"><a name="l00863"></a><span class="lineno"> 863</span>  }</div>
|
|
<div class="line"><a name="l00864"></a><span class="lineno"> 864</span>  offset += packet_length;</div>
|
|
<div class="line"><a name="l00865"></a><span class="lineno"> 865</span>  }</div>
|
|
<div class="line"><a name="l00866"></a><span class="lineno"> 866</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00867"></a><span class="lineno"> 867</span> }</div>
|
|
<div class="line"><a name="l00868"></a><span class="lineno"> 868</span> </div>
|
|
<div class="line"><a name="l00869"></a><span class="lineno"> 869</span> <span class="keyword">enum</span> Mpeg4StartCodes {</div>
|
|
<div class="line"><a name="l00870"></a><span class="lineno"> 870</span>  VISUAL_OBJECT_SEQUENCE_START_CODE = 0xb0,</div>
|
|
<div class="line"><a name="l00871"></a><span class="lineno"> 871</span>  VISUAL_OBJECT_SEQUENCE_END_CODE = 0xb1,</div>
|
|
<div class="line"><a name="l00872"></a><span class="lineno"> 872</span>  VISUAL_OBJECT_START_CODE = 0xb5,</div>
|
|
<div class="line"><a name="l00873"></a><span class="lineno"> 873</span>  VOP_START_CODE = 0xb6</div>
|
|
<div class="line"><a name="l00874"></a><span class="lineno"> 874</span> };</div>
|
|
<div class="line"><a name="l00875"></a><span class="lineno"> 875</span> </div>
|
|
<div class="line"><a name="l00876"></a><span class="lineno"> 876</span> <span class="comment">// Checks for a raw MPEG4 bitstream container.</span></div>
|
|
<div class="line"><a name="l00877"></a><span class="lineno"> 877</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckMpeg4BitStream(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00878"></a><span class="lineno"> 878</span>  <span class="comment">// Defined in ISO/IEC 14496-2:2001.</span></div>
|
|
<div class="line"><a name="l00879"></a><span class="lineno"> 879</span>  <span class="comment">// However, no length ... simply scan for start code values.</span></div>
|
|
<div class="line"><a name="l00880"></a><span class="lineno"> 880</span>  <span class="comment">// Note tags are very similar to H.264.</span></div>
|
|
<div class="line"><a name="l00881"></a><span class="lineno"> 881</span>  RCHECK(buffer_size > 4);</div>
|
|
<div class="line"><a name="l00882"></a><span class="lineno"> 882</span> </div>
|
|
<div class="line"><a name="l00883"></a><span class="lineno"> 883</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l00884"></a><span class="lineno"> 884</span>  <span class="keywordtype">int</span> sequence_start_count = 0;</div>
|
|
<div class="line"><a name="l00885"></a><span class="lineno"> 885</span>  <span class="keywordtype">int</span> sequence_end_count = 0;</div>
|
|
<div class="line"><a name="l00886"></a><span class="lineno"> 886</span>  <span class="keywordtype">int</span> visual_object_count = 0;</div>
|
|
<div class="line"><a name="l00887"></a><span class="lineno"> 887</span>  <span class="keywordtype">int</span> vop_count = 0;</div>
|
|
<div class="line"><a name="l00888"></a><span class="lineno"> 888</span>  <span class="keywordflow">while</span> (<span class="keyword">true</span>) {</div>
|
|
<div class="line"><a name="l00889"></a><span class="lineno"> 889</span>  <span class="comment">// Advance to start_code, if there is one.</span></div>
|
|
<div class="line"><a name="l00890"></a><span class="lineno"> 890</span>  <span class="keywordflow">if</span> (!AdvanceToStartCode(buffer, buffer_size, &offset, 6, 24, 1)) {</div>
|
|
<div class="line"><a name="l00891"></a><span class="lineno"> 891</span>  <span class="comment">// Not a complete sequence in memory, so return true if we've seen a</span></div>
|
|
<div class="line"><a name="l00892"></a><span class="lineno"> 892</span>  <span class="comment">// visual_object_sequence_start_code and a visual_object_start_code.</span></div>
|
|
<div class="line"><a name="l00893"></a><span class="lineno"> 893</span>  <span class="keywordflow">return</span> (sequence_start_count > 0 && visual_object_count > 0);</div>
|
|
<div class="line"><a name="l00894"></a><span class="lineno"> 894</span>  }</div>
|
|
<div class="line"><a name="l00895"></a><span class="lineno"> 895</span> </div>
|
|
<div class="line"><a name="l00896"></a><span class="lineno"> 896</span>  <span class="comment">// Now verify the block. AdvanceToStartCode() made sure that there are</span></div>
|
|
<div class="line"><a name="l00897"></a><span class="lineno"> 897</span>  <span class="comment">// at least 6 bytes remaining in the buffer.</span></div>
|
|
<div class="line"><a name="l00898"></a><span class="lineno"> 898</span>  BitReader reader(buffer + offset, 6);</div>
|
|
<div class="line"><a name="l00899"></a><span class="lineno"> 899</span>  RCHECK(ReadBits(&reader, 24) == 1);</div>
|
|
<div class="line"><a name="l00900"></a><span class="lineno"> 900</span> </div>
|
|
<div class="line"><a name="l00901"></a><span class="lineno"> 901</span>  <span class="keywordtype">int</span> start_code = ReadBits(&reader, 8);</div>
|
|
<div class="line"><a name="l00902"></a><span class="lineno"> 902</span>  RCHECK(start_code < 0x30 || start_code > 0xaf); <span class="comment">// 30..AF and</span></div>
|
|
<div class="line"><a name="l00903"></a><span class="lineno"> 903</span>  RCHECK(start_code < 0xb7 || start_code > 0xb9); <span class="comment">// B7..B9 reserved</span></div>
|
|
<div class="line"><a name="l00904"></a><span class="lineno"> 904</span> </div>
|
|
<div class="line"><a name="l00905"></a><span class="lineno"> 905</span>  <span class="keywordflow">switch</span> (start_code) {</div>
|
|
<div class="line"><a name="l00906"></a><span class="lineno"> 906</span>  <span class="keywordflow">case</span> VISUAL_OBJECT_SEQUENCE_START_CODE: {</div>
|
|
<div class="line"><a name="l00907"></a><span class="lineno"> 907</span>  ++sequence_start_count;</div>
|
|
<div class="line"><a name="l00908"></a><span class="lineno"> 908</span>  <span class="comment">// Verify profile in not one of many reserved values.</span></div>
|
|
<div class="line"><a name="l00909"></a><span class="lineno"> 909</span>  <span class="keywordtype">int</span> profile = ReadBits(&reader, 8);</div>
|
|
<div class="line"><a name="l00910"></a><span class="lineno"> 910</span>  RCHECK(profile > 0);</div>
|
|
<div class="line"><a name="l00911"></a><span class="lineno"> 911</span>  RCHECK(profile < 0x04 || profile > 0x10);</div>
|
|
<div class="line"><a name="l00912"></a><span class="lineno"> 912</span>  RCHECK(profile < 0x13 || profile > 0x20);</div>
|
|
<div class="line"><a name="l00913"></a><span class="lineno"> 913</span>  RCHECK(profile < 0x23 || profile > 0x31);</div>
|
|
<div class="line"><a name="l00914"></a><span class="lineno"> 914</span>  RCHECK(profile < 0x35 || profile > 0x41);</div>
|
|
<div class="line"><a name="l00915"></a><span class="lineno"> 915</span>  RCHECK(profile < 0x43 || profile > 0x60);</div>
|
|
<div class="line"><a name="l00916"></a><span class="lineno"> 916</span>  RCHECK(profile < 0x65 || profile > 0x70);</div>
|
|
<div class="line"><a name="l00917"></a><span class="lineno"> 917</span>  RCHECK(profile < 0x73 || profile > 0x80);</div>
|
|
<div class="line"><a name="l00918"></a><span class="lineno"> 918</span>  RCHECK(profile < 0x83 || profile > 0x90);</div>
|
|
<div class="line"><a name="l00919"></a><span class="lineno"> 919</span>  RCHECK(profile < 0x95 || profile > 0xa0);</div>
|
|
<div class="line"><a name="l00920"></a><span class="lineno"> 920</span>  RCHECK(profile < 0xa4 || profile > 0xb0);</div>
|
|
<div class="line"><a name="l00921"></a><span class="lineno"> 921</span>  RCHECK(profile < 0xb5 || profile > 0xc0);</div>
|
|
<div class="line"><a name="l00922"></a><span class="lineno"> 922</span>  RCHECK(profile < 0xc3 || profile > 0xd0);</div>
|
|
<div class="line"><a name="l00923"></a><span class="lineno"> 923</span>  RCHECK(profile < 0xe4);</div>
|
|
<div class="line"><a name="l00924"></a><span class="lineno"> 924</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l00925"></a><span class="lineno"> 925</span>  }</div>
|
|
<div class="line"><a name="l00926"></a><span class="lineno"> 926</span> </div>
|
|
<div class="line"><a name="l00927"></a><span class="lineno"> 927</span>  <span class="keywordflow">case</span> VISUAL_OBJECT_SEQUENCE_END_CODE:</div>
|
|
<div class="line"><a name="l00928"></a><span class="lineno"> 928</span>  RCHECK(++sequence_end_count == sequence_start_count);</div>
|
|
<div class="line"><a name="l00929"></a><span class="lineno"> 929</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l00930"></a><span class="lineno"> 930</span> </div>
|
|
<div class="line"><a name="l00931"></a><span class="lineno"> 931</span>  <span class="keywordflow">case</span> VISUAL_OBJECT_START_CODE: {</div>
|
|
<div class="line"><a name="l00932"></a><span class="lineno"> 932</span>  ++visual_object_count;</div>
|
|
<div class="line"><a name="l00933"></a><span class="lineno"> 933</span>  <span class="keywordflow">if</span> (ReadBits(&reader, 1) == 1) {</div>
|
|
<div class="line"><a name="l00934"></a><span class="lineno"> 934</span>  <span class="keywordtype">int</span> visual_object_verid = ReadBits(&reader, 4);</div>
|
|
<div class="line"><a name="l00935"></a><span class="lineno"> 935</span>  RCHECK(visual_object_verid > 0 && visual_object_verid < 3);</div>
|
|
<div class="line"><a name="l00936"></a><span class="lineno"> 936</span>  RCHECK(ReadBits(&reader, 3) != 0);</div>
|
|
<div class="line"><a name="l00937"></a><span class="lineno"> 937</span>  }</div>
|
|
<div class="line"><a name="l00938"></a><span class="lineno"> 938</span>  <span class="keywordtype">int</span> visual_object_type = ReadBits(&reader, 4);</div>
|
|
<div class="line"><a name="l00939"></a><span class="lineno"> 939</span>  RCHECK(visual_object_type > 0 && visual_object_type < 6);</div>
|
|
<div class="line"><a name="l00940"></a><span class="lineno"> 940</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l00941"></a><span class="lineno"> 941</span>  }</div>
|
|
<div class="line"><a name="l00942"></a><span class="lineno"> 942</span> </div>
|
|
<div class="line"><a name="l00943"></a><span class="lineno"> 943</span>  <span class="keywordflow">case</span> VOP_START_CODE:</div>
|
|
<div class="line"><a name="l00944"></a><span class="lineno"> 944</span>  RCHECK(++vop_count <= visual_object_count);</div>
|
|
<div class="line"><a name="l00945"></a><span class="lineno"> 945</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l00946"></a><span class="lineno"> 946</span>  }</div>
|
|
<div class="line"><a name="l00947"></a><span class="lineno"> 947</span>  <span class="comment">// Skip this block.</span></div>
|
|
<div class="line"><a name="l00948"></a><span class="lineno"> 948</span>  offset += 6;</div>
|
|
<div class="line"><a name="l00949"></a><span class="lineno"> 949</span>  }</div>
|
|
<div class="line"><a name="l00950"></a><span class="lineno"> 950</span> }</div>
|
|
<div class="line"><a name="l00951"></a><span class="lineno"> 951</span> </div>
|
|
<div class="line"><a name="l00952"></a><span class="lineno"> 952</span> <span class="comment">// Additional checks for a MOV/QuickTime/MPEG4 container.</span></div>
|
|
<div class="line"><a name="l00953"></a><span class="lineno"> 953</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckMov(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l00954"></a><span class="lineno"> 954</span>  <span class="comment">// Reference: ISO/IEC 14496-12:2005(E).</span></div>
|
|
<div class="line"><a name="l00955"></a><span class="lineno"> 955</span>  <span class="comment">// (http://standards.iso.org/ittf/PubliclyAvailableStandards/c061988_ISO_IEC_14496-12_2012.zip)</span></div>
|
|
<div class="line"><a name="l00956"></a><span class="lineno"> 956</span>  RCHECK(buffer_size > 8);</div>
|
|
<div class="line"><a name="l00957"></a><span class="lineno"> 957</span> </div>
|
|
<div class="line"><a name="l00958"></a><span class="lineno"> 958</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l00959"></a><span class="lineno"> 959</span>  <span class="keywordtype">int</span> boxes_seen = 0;</div>
|
|
<div class="line"><a name="l00960"></a><span class="lineno"> 960</span>  <span class="keywordflow">while</span> (offset + 8 < buffer_size) {</div>
|
|
<div class="line"><a name="l00961"></a><span class="lineno"> 961</span>  <span class="keywordtype">int</span> atomsize = Read32(buffer + offset);</div>
|
|
<div class="line"><a name="l00962"></a><span class="lineno"> 962</span>  uint32_t atomtype = Read32(buffer + offset + 4);</div>
|
|
<div class="line"><a name="l00963"></a><span class="lineno"> 963</span>  <span class="comment">// Only need to check for ones that are valid at the top level.</span></div>
|
|
<div class="line"><a name="l00964"></a><span class="lineno"> 964</span>  <span class="keywordflow">switch</span> (atomtype) {</div>
|
|
<div class="line"><a name="l00965"></a><span class="lineno"> 965</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'f'</span>,<span class="charliteral">'t'</span>,<span class="charliteral">'y'</span>,<span class="charliteral">'p'</span>):</div>
|
|
<div class="line"><a name="l00966"></a><span class="lineno"> 966</span>  case TAG(<span class="stringliteral">'p'</span>,<span class="stringliteral">'d'</span>,<span class="stringliteral">'i'</span>,<span class="stringliteral">'n'</span>):</div>
|
|
<div class="line"><a name="l00967"></a><span class="lineno"> 967</span>  case TAG(<span class="stringliteral">'b'</span>,<span class="stringliteral">'l'</span>,<span class="stringliteral">'o'</span>,<span class="stringliteral">'c'</span>):</div>
|
|
<div class="line"><a name="l00968"></a><span class="lineno"> 968</span>  case TAG(<span class="stringliteral">'m'</span>,<span class="stringliteral">'o'</span>,<span class="stringliteral">'o'</span>,<span class="stringliteral">'v'</span>):</div>
|
|
<div class="line"><a name="l00969"></a><span class="lineno"> 969</span>  case TAG(<span class="stringliteral">'m'</span>,<span class="stringliteral">'o'</span>,<span class="stringliteral">'o'</span>,<span class="stringliteral">'f'</span>):</div>
|
|
<div class="line"><a name="l00970"></a><span class="lineno"> 970</span>  case TAG(<span class="stringliteral">'m'</span>,<span class="stringliteral">'f'</span>,<span class="stringliteral">'r'</span>,<span class="stringliteral">'a'</span>):</div>
|
|
<div class="line"><a name="l00971"></a><span class="lineno"> 971</span>  case TAG(<span class="stringliteral">'m'</span>,<span class="stringliteral">'d'</span>,<span class="stringliteral">'a'</span>,<span class="stringliteral">'t'</span>):</div>
|
|
<div class="line"><a name="l00972"></a><span class="lineno"> 972</span>  case TAG(<span class="stringliteral">'f'</span>,<span class="stringliteral">'r'</span>,<span class="stringliteral">'e'</span>,<span class="stringliteral">'e'</span>):</div>
|
|
<div class="line"><a name="l00973"></a><span class="lineno"> 973</span>  case TAG(<span class="stringliteral">'s'</span>,<span class="stringliteral">'k'</span>,<span class="stringliteral">'i'</span>,<span class="stringliteral">'p'</span>):</div>
|
|
<div class="line"><a name="l00974"></a><span class="lineno"> 974</span>  case TAG(<span class="stringliteral">'m'</span>,<span class="stringliteral">'e'</span>,<span class="stringliteral">'t'</span>,<span class="stringliteral">'a'</span>):</div>
|
|
<div class="line"><a name="l00975"></a><span class="lineno"> 975</span>  case TAG(<span class="stringliteral">'m'</span>,<span class="stringliteral">'e'</span>,<span class="stringliteral">'c'</span>,<span class="stringliteral">'o'</span>):</div>
|
|
<div class="line"><a name="l00976"></a><span class="lineno"> 976</span>  case TAG(<span class="stringliteral">'s'</span>,<span class="stringliteral">'t'</span>,<span class="stringliteral">'y'</span>,<span class="stringliteral">'p'</span>):</div>
|
|
<div class="line"><a name="l00977"></a><span class="lineno"> 977</span>  case TAG(<span class="stringliteral">'s'</span>,<span class="stringliteral">'i'</span>,<span class="stringliteral">'d'</span>,<span class="stringliteral">'x'</span>):</div>
|
|
<div class="line"><a name="l00978"></a><span class="lineno"> 978</span>  case TAG(<span class="stringliteral">'s'</span>,<span class="stringliteral">'s'</span>,<span class="stringliteral">'i'</span>,<span class="stringliteral">'x'</span>):</div>
|
|
<div class="line"><a name="l00979"></a><span class="lineno"> 979</span>  case TAG(<span class="stringliteral">'p'</span>,<span class="stringliteral">'r'</span>,<span class="stringliteral">'f'</span>,<span class="stringliteral">'t'</span>):</div>
|
|
<div class="line"><a name="l00980"></a><span class="lineno"> 980</span>  case TAG(<span class="stringliteral">'u'</span>,<span class="stringliteral">'u'</span>,<span class="stringliteral">'i'</span>,<span class="stringliteral">'d'</span>):</div>
|
|
<div class="line"><a name="l00981"></a><span class="lineno"> 981</span>  <span class="comment">// Assumes that it is an iso-bmff file after seeing two known boxes.</span></div>
|
|
<div class="line"><a name="l00982"></a><span class="lineno"> 982</span>  <span class="comment">// Note that it is correct only for our use cases as we support only</span></div>
|
|
<div class="line"><a name="l00983"></a><span class="lineno"> 983</span>  <span class="comment">// a limited number of containers, and there is no other container</span></div>
|
|
<div class="line"><a name="l00984"></a><span class="lineno"> 984</span>  <span class="comment">// has this behavior.</span></div>
|
|
<div class="line"><a name="l00985"></a><span class="lineno"> 985</span>  if (++boxes_seen >= 2)</div>
|
|
<div class="line"><a name="l00986"></a><span class="lineno"> 986</span>  return true;</div>
|
|
<div class="line"><a name="l00987"></a><span class="lineno"> 987</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l00988"></a><span class="lineno"> 988</span>  <span class="keywordflow">default</span>:</div>
|
|
<div class="line"><a name="l00989"></a><span class="lineno"> 989</span>  <span class="comment">// Ignore unrecognized box.</span></div>
|
|
<div class="line"><a name="l00990"></a><span class="lineno"> 990</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l00991"></a><span class="lineno"> 991</span>  }</div>
|
|
<div class="line"><a name="l00992"></a><span class="lineno"> 992</span>  <span class="keywordflow">if</span> (atomsize == 1) {</div>
|
|
<div class="line"><a name="l00993"></a><span class="lineno"> 993</span>  <span class="comment">// Indicates that the length is the next 64bits.</span></div>
|
|
<div class="line"><a name="l00994"></a><span class="lineno"> 994</span>  <span class="keywordflow">if</span> (offset + 16 > buffer_size)</div>
|
|
<div class="line"><a name="l00995"></a><span class="lineno"> 995</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l00996"></a><span class="lineno"> 996</span>  <span class="keywordflow">if</span> (Read32(buffer + offset + 8) != 0)</div>
|
|
<div class="line"><a name="l00997"></a><span class="lineno"> 997</span>  <span class="keywordflow">break</span>; <span class="comment">// Offset is way past buffer size.</span></div>
|
|
<div class="line"><a name="l00998"></a><span class="lineno"> 998</span>  atomsize = Read32(buffer + offset + 12);</div>
|
|
<div class="line"><a name="l00999"></a><span class="lineno"> 999</span>  }</div>
|
|
<div class="line"><a name="l01000"></a><span class="lineno"> 1000</span>  <span class="keywordflow">if</span> (atomsize <= 0)</div>
|
|
<div class="line"><a name="l01001"></a><span class="lineno"> 1001</span>  <span class="keywordflow">break</span>; <span class="comment">// Indicates the last atom or length too big.</span></div>
|
|
<div class="line"><a name="l01002"></a><span class="lineno"> 1002</span>  offset += atomsize;</div>
|
|
<div class="line"><a name="l01003"></a><span class="lineno"> 1003</span>  }</div>
|
|
<div class="line"><a name="l01004"></a><span class="lineno"> 1004</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l01005"></a><span class="lineno"> 1005</span> }</div>
|
|
<div class="line"><a name="l01006"></a><span class="lineno"> 1006</span> </div>
|
|
<div class="line"><a name="l01007"></a><span class="lineno"> 1007</span> <span class="keyword">enum</span> MPEGVersion {</div>
|
|
<div class="line"><a name="l01008"></a><span class="lineno"> 1008</span>  VERSION_25 = 0,</div>
|
|
<div class="line"><a name="l01009"></a><span class="lineno"> 1009</span>  VERSION_RESERVED,</div>
|
|
<div class="line"><a name="l01010"></a><span class="lineno"> 1010</span>  VERSION_2,</div>
|
|
<div class="line"><a name="l01011"></a><span class="lineno"> 1011</span>  VERSION_1</div>
|
|
<div class="line"><a name="l01012"></a><span class="lineno"> 1012</span> };</div>
|
|
<div class="line"><a name="l01013"></a><span class="lineno"> 1013</span> <span class="keyword">enum</span> MPEGLayer {</div>
|
|
<div class="line"><a name="l01014"></a><span class="lineno"> 1014</span>  L_RESERVED = 0,</div>
|
|
<div class="line"><a name="l01015"></a><span class="lineno"> 1015</span>  LAYER_3,</div>
|
|
<div class="line"><a name="l01016"></a><span class="lineno"> 1016</span>  LAYER_2,</div>
|
|
<div class="line"><a name="l01017"></a><span class="lineno"> 1017</span>  LAYER_1</div>
|
|
<div class="line"><a name="l01018"></a><span class="lineno"> 1018</span> };</div>
|
|
<div class="line"><a name="l01019"></a><span class="lineno"> 1019</span> </div>
|
|
<div class="line"><a name="l01020"></a><span class="lineno"> 1020</span> <span class="keyword">static</span> <span class="keywordtype">int</span> kSampleRateTable[4][4] = { { 11025, 12000, 8000, 0 }, <span class="comment">// v2.5</span></div>
|
|
<div class="line"><a name="l01021"></a><span class="lineno"> 1021</span>  { 0, 0, 0, 0 }, <span class="comment">// not used</span></div>
|
|
<div class="line"><a name="l01022"></a><span class="lineno"> 1022</span>  { 22050, 24000, 16000, 0 }, <span class="comment">// v2</span></div>
|
|
<div class="line"><a name="l01023"></a><span class="lineno"> 1023</span>  { 44100, 48000, 32000, 0 } <span class="comment">// v1</span></div>
|
|
<div class="line"><a name="l01024"></a><span class="lineno"> 1024</span> };</div>
|
|
<div class="line"><a name="l01025"></a><span class="lineno"> 1025</span> </div>
|
|
<div class="line"><a name="l01026"></a><span class="lineno"> 1026</span> <span class="keyword">static</span> <span class="keywordtype">int</span> kBitRateTableV1L1[16] = { 0, 32, 64, 96, 128, 160, 192, 224, 256,</div>
|
|
<div class="line"><a name="l01027"></a><span class="lineno"> 1027</span>  288, 320, 352, 384, 416, 448, 0 };</div>
|
|
<div class="line"><a name="l01028"></a><span class="lineno"> 1028</span> <span class="keyword">static</span> <span class="keywordtype">int</span> kBitRateTableV1L2[16] = { 0, 32, 48, 56, 64, 80, 96, 112, 128, 160,</div>
|
|
<div class="line"><a name="l01029"></a><span class="lineno"> 1029</span>  192, 224, 256, 320, 384, 0 };</div>
|
|
<div class="line"><a name="l01030"></a><span class="lineno"> 1030</span> <span class="keyword">static</span> <span class="keywordtype">int</span> kBitRateTableV1L3[16] = { 0, 32, 40, 48, 56, 64, 80, 96, 112, 128,</div>
|
|
<div class="line"><a name="l01031"></a><span class="lineno"> 1031</span>  160, 192, 224, 256, 320, 0 };</div>
|
|
<div class="line"><a name="l01032"></a><span class="lineno"> 1032</span> <span class="keyword">static</span> <span class="keywordtype">int</span> kBitRateTableV2L1[16] = { 0, 32, 48, 56, 64, 80, 96, 112, 128, 144,</div>
|
|
<div class="line"><a name="l01033"></a><span class="lineno"> 1033</span>  160, 176, 192, 224, 256, 0 };</div>
|
|
<div class="line"><a name="l01034"></a><span class="lineno"> 1034</span> <span class="keyword">static</span> <span class="keywordtype">int</span> kBitRateTableV2L23[16] = { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96,</div>
|
|
<div class="line"><a name="l01035"></a><span class="lineno"> 1035</span>  112, 128, 144, 160, 0 };</div>
|
|
<div class="line"><a name="l01036"></a><span class="lineno"> 1036</span> </div>
|
|
<div class="line"><a name="l01037"></a><span class="lineno"> 1037</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> ValidMpegAudioFrameHeader(<span class="keyword">const</span> uint8_t* header,</div>
|
|
<div class="line"><a name="l01038"></a><span class="lineno"> 1038</span>  <span class="keywordtype">int</span> header_size,</div>
|
|
<div class="line"><a name="l01039"></a><span class="lineno"> 1039</span>  <span class="keywordtype">int</span>* framesize) {</div>
|
|
<div class="line"><a name="l01040"></a><span class="lineno"> 1040</span>  <span class="comment">// Reference: http://mpgedit.org/mpgedit/mpeg_format/mpeghdr.htm.</span></div>
|
|
<div class="line"><a name="l01041"></a><span class="lineno"> 1041</span>  DCHECK_GE(header_size, 4);</div>
|
|
<div class="line"><a name="l01042"></a><span class="lineno"> 1042</span>  *framesize = 0;</div>
|
|
<div class="line"><a name="l01043"></a><span class="lineno"> 1043</span>  BitReader reader(header, 4); <span class="comment">// Header can only be 4 bytes long.</span></div>
|
|
<div class="line"><a name="l01044"></a><span class="lineno"> 1044</span> </div>
|
|
<div class="line"><a name="l01045"></a><span class="lineno"> 1045</span>  <span class="comment">// Verify frame sync (11 bits) are all set.</span></div>
|
|
<div class="line"><a name="l01046"></a><span class="lineno"> 1046</span>  RCHECK(ReadBits(&reader, 11) == 0x7ff);</div>
|
|
<div class="line"><a name="l01047"></a><span class="lineno"> 1047</span> </div>
|
|
<div class="line"><a name="l01048"></a><span class="lineno"> 1048</span>  <span class="comment">// Verify MPEG audio version id.</span></div>
|
|
<div class="line"><a name="l01049"></a><span class="lineno"> 1049</span>  <span class="keywordtype">int</span> version = ReadBits(&reader, 2);</div>
|
|
<div class="line"><a name="l01050"></a><span class="lineno"> 1050</span>  RCHECK(version != 1); <span class="comment">// Reserved.</span></div>
|
|
<div class="line"><a name="l01051"></a><span class="lineno"> 1051</span> </div>
|
|
<div class="line"><a name="l01052"></a><span class="lineno"> 1052</span>  <span class="comment">// Verify layer.</span></div>
|
|
<div class="line"><a name="l01053"></a><span class="lineno"> 1053</span>  <span class="keywordtype">int</span> layer = ReadBits(&reader, 2);</div>
|
|
<div class="line"><a name="l01054"></a><span class="lineno"> 1054</span>  RCHECK(layer != 0);</div>
|
|
<div class="line"><a name="l01055"></a><span class="lineno"> 1055</span> </div>
|
|
<div class="line"><a name="l01056"></a><span class="lineno"> 1056</span>  <span class="comment">// Skip protection bit.</span></div>
|
|
<div class="line"><a name="l01057"></a><span class="lineno"> 1057</span>  reader.SkipBits(1);</div>
|
|
<div class="line"><a name="l01058"></a><span class="lineno"> 1058</span> </div>
|
|
<div class="line"><a name="l01059"></a><span class="lineno"> 1059</span>  <span class="comment">// Verify bitrate index.</span></div>
|
|
<div class="line"><a name="l01060"></a><span class="lineno"> 1060</span>  <span class="keywordtype">int</span> bitrate_index = ReadBits(&reader, 4);</div>
|
|
<div class="line"><a name="l01061"></a><span class="lineno"> 1061</span>  RCHECK(bitrate_index != 0xf);</div>
|
|
<div class="line"><a name="l01062"></a><span class="lineno"> 1062</span> </div>
|
|
<div class="line"><a name="l01063"></a><span class="lineno"> 1063</span>  <span class="comment">// Verify sampling rate frequency index.</span></div>
|
|
<div class="line"><a name="l01064"></a><span class="lineno"> 1064</span>  <span class="keywordtype">int</span> sampling_index = ReadBits(&reader, 2);</div>
|
|
<div class="line"><a name="l01065"></a><span class="lineno"> 1065</span>  RCHECK(sampling_index != 3);</div>
|
|
<div class="line"><a name="l01066"></a><span class="lineno"> 1066</span> </div>
|
|
<div class="line"><a name="l01067"></a><span class="lineno"> 1067</span>  <span class="comment">// Get padding bit.</span></div>
|
|
<div class="line"><a name="l01068"></a><span class="lineno"> 1068</span>  <span class="keywordtype">int</span> padding = ReadBits(&reader, 1);</div>
|
|
<div class="line"><a name="l01069"></a><span class="lineno"> 1069</span> </div>
|
|
<div class="line"><a name="l01070"></a><span class="lineno"> 1070</span>  <span class="comment">// Frame size:</span></div>
|
|
<div class="line"><a name="l01071"></a><span class="lineno"> 1071</span>  <span class="comment">// For Layer I files = (12 * BitRate / SampleRate + Padding) * 4</span></div>
|
|
<div class="line"><a name="l01072"></a><span class="lineno"> 1072</span>  <span class="comment">// For others = 144 * BitRate / SampleRate + Padding</span></div>
|
|
<div class="line"><a name="l01073"></a><span class="lineno"> 1073</span>  <span class="comment">// Unfortunately, BitRate and SampleRate are coded.</span></div>
|
|
<div class="line"><a name="l01074"></a><span class="lineno"> 1074</span>  <span class="keywordtype">int</span> sampling_rate = kSampleRateTable[version][sampling_index];</div>
|
|
<div class="line"><a name="l01075"></a><span class="lineno"> 1075</span>  <span class="keywordtype">int</span> bitrate;</div>
|
|
<div class="line"><a name="l01076"></a><span class="lineno"> 1076</span>  <span class="keywordflow">if</span> (version == VERSION_1) {</div>
|
|
<div class="line"><a name="l01077"></a><span class="lineno"> 1077</span>  <span class="keywordflow">if</span> (layer == LAYER_1)</div>
|
|
<div class="line"><a name="l01078"></a><span class="lineno"> 1078</span>  bitrate = kBitRateTableV1L1[bitrate_index];</div>
|
|
<div class="line"><a name="l01079"></a><span class="lineno"> 1079</span>  <span class="keywordflow">else</span> <span class="keywordflow">if</span> (layer == LAYER_2)</div>
|
|
<div class="line"><a name="l01080"></a><span class="lineno"> 1080</span>  bitrate = kBitRateTableV1L2[bitrate_index];</div>
|
|
<div class="line"><a name="l01081"></a><span class="lineno"> 1081</span>  <span class="keywordflow">else</span></div>
|
|
<div class="line"><a name="l01082"></a><span class="lineno"> 1082</span>  bitrate = kBitRateTableV1L3[bitrate_index];</div>
|
|
<div class="line"><a name="l01083"></a><span class="lineno"> 1083</span>  } <span class="keywordflow">else</span> {</div>
|
|
<div class="line"><a name="l01084"></a><span class="lineno"> 1084</span>  <span class="keywordflow">if</span> (layer == LAYER_1)</div>
|
|
<div class="line"><a name="l01085"></a><span class="lineno"> 1085</span>  bitrate = kBitRateTableV2L1[bitrate_index];</div>
|
|
<div class="line"><a name="l01086"></a><span class="lineno"> 1086</span>  <span class="keywordflow">else</span></div>
|
|
<div class="line"><a name="l01087"></a><span class="lineno"> 1087</span>  bitrate = kBitRateTableV2L23[bitrate_index];</div>
|
|
<div class="line"><a name="l01088"></a><span class="lineno"> 1088</span>  }</div>
|
|
<div class="line"><a name="l01089"></a><span class="lineno"> 1089</span>  <span class="keywordflow">if</span> (layer == LAYER_1)</div>
|
|
<div class="line"><a name="l01090"></a><span class="lineno"> 1090</span>  *framesize = ((12000 * bitrate) / sampling_rate + padding) * 4;</div>
|
|
<div class="line"><a name="l01091"></a><span class="lineno"> 1091</span>  <span class="keywordflow">else</span></div>
|
|
<div class="line"><a name="l01092"></a><span class="lineno"> 1092</span>  *framesize = (144000 * bitrate) / sampling_rate + padding;</div>
|
|
<div class="line"><a name="l01093"></a><span class="lineno"> 1093</span>  <span class="keywordflow">return</span> (bitrate > 0 && sampling_rate > 0);</div>
|
|
<div class="line"><a name="l01094"></a><span class="lineno"> 1094</span> }</div>
|
|
<div class="line"><a name="l01095"></a><span class="lineno"> 1095</span> </div>
|
|
<div class="line"><a name="l01096"></a><span class="lineno"> 1096</span> <span class="comment">// Extract a size encoded the MP3 way.</span></div>
|
|
<div class="line"><a name="l01097"></a><span class="lineno"> 1097</span> <span class="keyword">static</span> <span class="keywordtype">int</span> GetMp3HeaderSize(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l01098"></a><span class="lineno"> 1098</span>  DCHECK_GE(buffer_size, 9);</div>
|
|
<div class="line"><a name="l01099"></a><span class="lineno"> 1099</span>  <span class="keywordtype">int</span> size = ((buffer[6] & 0x7f) << 21) + ((buffer[7] & 0x7f) << 14) +</div>
|
|
<div class="line"><a name="l01100"></a><span class="lineno"> 1100</span>  ((buffer[8] & 0x7f) << 7) + (buffer[9] & 0x7f) + 10;</div>
|
|
<div class="line"><a name="l01101"></a><span class="lineno"> 1101</span>  <span class="keywordflow">if</span> (buffer[5] & 0x10) <span class="comment">// Footer added?</span></div>
|
|
<div class="line"><a name="l01102"></a><span class="lineno"> 1102</span>  size += 10;</div>
|
|
<div class="line"><a name="l01103"></a><span class="lineno"> 1103</span>  <span class="keywordflow">return</span> size;</div>
|
|
<div class="line"><a name="l01104"></a><span class="lineno"> 1104</span> }</div>
|
|
<div class="line"><a name="l01105"></a><span class="lineno"> 1105</span> </div>
|
|
<div class="line"><a name="l01106"></a><span class="lineno"> 1106</span> <span class="comment">// Additional checks for a MP3 container.</span></div>
|
|
<div class="line"><a name="l01107"></a><span class="lineno"> 1107</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckMp3(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size, <span class="keywordtype">bool</span> seenHeader) {</div>
|
|
<div class="line"><a name="l01108"></a><span class="lineno"> 1108</span>  RCHECK(buffer_size >= 10); <span class="comment">// Must be enough to read the initial header.</span></div>
|
|
<div class="line"><a name="l01109"></a><span class="lineno"> 1109</span> </div>
|
|
<div class="line"><a name="l01110"></a><span class="lineno"> 1110</span>  <span class="keywordtype">int</span> framesize;</div>
|
|
<div class="line"><a name="l01111"></a><span class="lineno"> 1111</span>  <span class="keywordtype">int</span> numSeen = 0;</div>
|
|
<div class="line"><a name="l01112"></a><span class="lineno"> 1112</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l01113"></a><span class="lineno"> 1113</span>  <span class="keywordflow">if</span> (seenHeader) {</div>
|
|
<div class="line"><a name="l01114"></a><span class="lineno"> 1114</span>  offset = GetMp3HeaderSize(buffer, buffer_size);</div>
|
|
<div class="line"><a name="l01115"></a><span class="lineno"> 1115</span>  } <span class="keywordflow">else</span> {</div>
|
|
<div class="line"><a name="l01116"></a><span class="lineno"> 1116</span>  <span class="comment">// Skip over leading 0's.</span></div>
|
|
<div class="line"><a name="l01117"></a><span class="lineno"> 1117</span>  <span class="keywordflow">while</span> (offset < buffer_size && buffer[offset] == 0)</div>
|
|
<div class="line"><a name="l01118"></a><span class="lineno"> 1118</span>  ++offset;</div>
|
|
<div class="line"><a name="l01119"></a><span class="lineno"> 1119</span>  }</div>
|
|
<div class="line"><a name="l01120"></a><span class="lineno"> 1120</span> </div>
|
|
<div class="line"><a name="l01121"></a><span class="lineno"> 1121</span>  <span class="keywordflow">while</span> (offset + 3 < buffer_size) {</div>
|
|
<div class="line"><a name="l01122"></a><span class="lineno"> 1122</span>  RCHECK(ValidMpegAudioFrameHeader(</div>
|
|
<div class="line"><a name="l01123"></a><span class="lineno"> 1123</span>  buffer + offset, buffer_size - offset, &framesize));</div>
|
|
<div class="line"><a name="l01124"></a><span class="lineno"> 1124</span> </div>
|
|
<div class="line"><a name="l01125"></a><span class="lineno"> 1125</span>  <span class="comment">// Have we seen enough valid headers?</span></div>
|
|
<div class="line"><a name="l01126"></a><span class="lineno"> 1126</span>  <span class="keywordflow">if</span> (++numSeen > 10)</div>
|
|
<div class="line"><a name="l01127"></a><span class="lineno"> 1127</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l01128"></a><span class="lineno"> 1128</span>  offset += framesize;</div>
|
|
<div class="line"><a name="l01129"></a><span class="lineno"> 1129</span>  }</div>
|
|
<div class="line"><a name="l01130"></a><span class="lineno"> 1130</span>  <span class="comment">// Off the end of the buffer, return success if a few valid headers seen.</span></div>
|
|
<div class="line"><a name="l01131"></a><span class="lineno"> 1131</span>  <span class="keywordflow">return</span> numSeen > 2;</div>
|
|
<div class="line"><a name="l01132"></a><span class="lineno"> 1132</span> }</div>
|
|
<div class="line"><a name="l01133"></a><span class="lineno"> 1133</span> </div>
|
|
<div class="line"><a name="l01134"></a><span class="lineno"> 1134</span> <span class="comment">// Check that the next characters in |buffer| represent a number. The format</span></div>
|
|
<div class="line"><a name="l01135"></a><span class="lineno"> 1135</span> <span class="comment">// accepted is optional whitespace followed by 1 or more digits. |max_digits|</span></div>
|
|
<div class="line"><a name="l01136"></a><span class="lineno"> 1136</span> <span class="comment">// specifies the maximum number of digits to process. Returns true if a valid</span></div>
|
|
<div class="line"><a name="l01137"></a><span class="lineno"> 1137</span> <span class="comment">// number is found, false otherwise.</span></div>
|
|
<div class="line"><a name="l01138"></a><span class="lineno"> 1138</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> VerifyNumber(<span class="keyword">const</span> uint8_t* buffer,</div>
|
|
<div class="line"><a name="l01139"></a><span class="lineno"> 1139</span>  <span class="keywordtype">int</span> buffer_size,</div>
|
|
<div class="line"><a name="l01140"></a><span class="lineno"> 1140</span>  <span class="keywordtype">int</span>* offset,</div>
|
|
<div class="line"><a name="l01141"></a><span class="lineno"> 1141</span>  <span class="keywordtype">int</span> max_digits) {</div>
|
|
<div class="line"><a name="l01142"></a><span class="lineno"> 1142</span>  RCHECK(*offset < buffer_size);</div>
|
|
<div class="line"><a name="l01143"></a><span class="lineno"> 1143</span> </div>
|
|
<div class="line"><a name="l01144"></a><span class="lineno"> 1144</span>  <span class="comment">// Skip over any leading space.</span></div>
|
|
<div class="line"><a name="l01145"></a><span class="lineno"> 1145</span>  <span class="keywordflow">while</span> (isspace(buffer[*offset])) {</div>
|
|
<div class="line"><a name="l01146"></a><span class="lineno"> 1146</span>  ++(*offset);</div>
|
|
<div class="line"><a name="l01147"></a><span class="lineno"> 1147</span>  RCHECK(*offset < buffer_size);</div>
|
|
<div class="line"><a name="l01148"></a><span class="lineno"> 1148</span>  }</div>
|
|
<div class="line"><a name="l01149"></a><span class="lineno"> 1149</span> </div>
|
|
<div class="line"><a name="l01150"></a><span class="lineno"> 1150</span>  <span class="comment">// Need to process up to max_digits digits.</span></div>
|
|
<div class="line"><a name="l01151"></a><span class="lineno"> 1151</span>  <span class="keywordtype">int</span> numSeen = 0;</div>
|
|
<div class="line"><a name="l01152"></a><span class="lineno"> 1152</span>  <span class="keywordflow">while</span> (--max_digits >= 0 && isdigit(buffer[*offset])) {</div>
|
|
<div class="line"><a name="l01153"></a><span class="lineno"> 1153</span>  ++numSeen;</div>
|
|
<div class="line"><a name="l01154"></a><span class="lineno"> 1154</span>  ++(*offset);</div>
|
|
<div class="line"><a name="l01155"></a><span class="lineno"> 1155</span>  <span class="keywordflow">if</span> (*offset >= buffer_size)</div>
|
|
<div class="line"><a name="l01156"></a><span class="lineno"> 1156</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>; <span class="comment">// Out of space but seen a digit.</span></div>
|
|
<div class="line"><a name="l01157"></a><span class="lineno"> 1157</span>  }</div>
|
|
<div class="line"><a name="l01158"></a><span class="lineno"> 1158</span> </div>
|
|
<div class="line"><a name="l01159"></a><span class="lineno"> 1159</span>  <span class="comment">// Success if at least one digit seen.</span></div>
|
|
<div class="line"><a name="l01160"></a><span class="lineno"> 1160</span>  <span class="keywordflow">return</span> (numSeen > 0);</div>
|
|
<div class="line"><a name="l01161"></a><span class="lineno"> 1161</span> }</div>
|
|
<div class="line"><a name="l01162"></a><span class="lineno"> 1162</span> </div>
|
|
<div class="line"><a name="l01163"></a><span class="lineno"> 1163</span> <span class="comment">// Check that the next character in |buffer| is one of |c1| or |c2|. |c2| is</span></div>
|
|
<div class="line"><a name="l01164"></a><span class="lineno"> 1164</span> <span class="comment">// optional. Returns true if there is a match, false if no match or out of</span></div>
|
|
<div class="line"><a name="l01165"></a><span class="lineno"> 1165</span> <span class="comment">// space.</span></div>
|
|
<div class="line"><a name="l01166"></a><span class="lineno"> 1166</span> <span class="keyword">static</span> <span class="keyword">inline</span> <span class="keywordtype">bool</span> VerifyCharacters(<span class="keyword">const</span> uint8_t* buffer,</div>
|
|
<div class="line"><a name="l01167"></a><span class="lineno"> 1167</span>  <span class="keywordtype">int</span> buffer_size,</div>
|
|
<div class="line"><a name="l01168"></a><span class="lineno"> 1168</span>  <span class="keywordtype">int</span>* offset,</div>
|
|
<div class="line"><a name="l01169"></a><span class="lineno"> 1169</span>  <span class="keywordtype">char</span> c1,</div>
|
|
<div class="line"><a name="l01170"></a><span class="lineno"> 1170</span>  <span class="keywordtype">char</span> c2) {</div>
|
|
<div class="line"><a name="l01171"></a><span class="lineno"> 1171</span>  RCHECK(*offset < buffer_size);</div>
|
|
<div class="line"><a name="l01172"></a><span class="lineno"> 1172</span>  <span class="keywordtype">char</span> c = <span class="keyword">static_cast<</span><span class="keywordtype">char</span><span class="keyword">></span>(buffer[(*offset)++]);</div>
|
|
<div class="line"><a name="l01173"></a><span class="lineno"> 1173</span>  <span class="keywordflow">return</span> (c == c1 || (c == c2 && c2 != 0));</div>
|
|
<div class="line"><a name="l01174"></a><span class="lineno"> 1174</span> }</div>
|
|
<div class="line"><a name="l01175"></a><span class="lineno"> 1175</span> </div>
|
|
<div class="line"><a name="l01176"></a><span class="lineno"> 1176</span> <span class="comment">// Checks for a SRT container.</span></div>
|
|
<div class="line"><a name="l01177"></a><span class="lineno"> 1177</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckSrt(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l01178"></a><span class="lineno"> 1178</span>  <span class="comment">// Reference: http://en.wikipedia.org/wiki/SubRip</span></div>
|
|
<div class="line"><a name="l01179"></a><span class="lineno"> 1179</span>  RCHECK(buffer_size > 20);</div>
|
|
<div class="line"><a name="l01180"></a><span class="lineno"> 1180</span> </div>
|
|
<div class="line"><a name="l01181"></a><span class="lineno"> 1181</span>  <span class="comment">// First line should just be the subtitle sequence number.</span></div>
|
|
<div class="line"><a name="l01182"></a><span class="lineno"> 1182</span>  <span class="keywordtype">int</span> offset = StartsWith(buffer, buffer_size, UTF8_BYTE_ORDER_MARK) ? 3 : 0;</div>
|
|
<div class="line"><a name="l01183"></a><span class="lineno"> 1183</span>  RCHECK(VerifyNumber(buffer, buffer_size, &offset, 100));</div>
|
|
<div class="line"><a name="l01184"></a><span class="lineno"> 1184</span>  RCHECK(VerifyCharacters(buffer, buffer_size, &offset, <span class="charliteral">'\n'</span>, <span class="charliteral">'\r'</span>));</div>
|
|
<div class="line"><a name="l01185"></a><span class="lineno"> 1185</span> </div>
|
|
<div class="line"><a name="l01186"></a><span class="lineno"> 1186</span>  <span class="comment">// Skip any additional \n\r.</span></div>
|
|
<div class="line"><a name="l01187"></a><span class="lineno"> 1187</span>  <span class="keywordflow">while</span> (VerifyCharacters(buffer, buffer_size, &offset, <span class="charliteral">'\n'</span>, <span class="charliteral">'\r'</span>)) {}</div>
|
|
<div class="line"><a name="l01188"></a><span class="lineno"> 1188</span>  --offset; <span class="comment">// Since VerifyCharacters() gobbled up the next non-CR/LF.</span></div>
|
|
<div class="line"><a name="l01189"></a><span class="lineno"> 1189</span> </div>
|
|
<div class="line"><a name="l01190"></a><span class="lineno"> 1190</span>  <span class="comment">// Second line should look like the following:</span></div>
|
|
<div class="line"><a name="l01191"></a><span class="lineno"> 1191</span>  <span class="comment">// 00:00:10,500 --> 00:00:13,000</span></div>
|
|
<div class="line"><a name="l01192"></a><span class="lineno"> 1192</span>  <span class="comment">// Units separator can be , or .</span></div>
|
|
<div class="line"><a name="l01193"></a><span class="lineno"> 1193</span>  RCHECK(VerifyNumber(buffer, buffer_size, &offset, 100));</div>
|
|
<div class="line"><a name="l01194"></a><span class="lineno"> 1194</span>  RCHECK(VerifyCharacters(buffer, buffer_size, &offset, <span class="charliteral">':'</span>, 0));</div>
|
|
<div class="line"><a name="l01195"></a><span class="lineno"> 1195</span>  RCHECK(VerifyNumber(buffer, buffer_size, &offset, 2));</div>
|
|
<div class="line"><a name="l01196"></a><span class="lineno"> 1196</span>  RCHECK(VerifyCharacters(buffer, buffer_size, &offset, <span class="charliteral">':'</span>, 0));</div>
|
|
<div class="line"><a name="l01197"></a><span class="lineno"> 1197</span>  RCHECK(VerifyNumber(buffer, buffer_size, &offset, 2));</div>
|
|
<div class="line"><a name="l01198"></a><span class="lineno"> 1198</span>  RCHECK(VerifyCharacters(buffer, buffer_size, &offset, <span class="charliteral">','</span>, <span class="charliteral">'.'</span>));</div>
|
|
<div class="line"><a name="l01199"></a><span class="lineno"> 1199</span>  RCHECK(VerifyNumber(buffer, buffer_size, &offset, 3));</div>
|
|
<div class="line"><a name="l01200"></a><span class="lineno"> 1200</span>  RCHECK(VerifyCharacters(buffer, buffer_size, &offset, <span class="charliteral">' '</span>, 0));</div>
|
|
<div class="line"><a name="l01201"></a><span class="lineno"> 1201</span>  RCHECK(VerifyCharacters(buffer, buffer_size, &offset, <span class="charliteral">'-'</span>, 0));</div>
|
|
<div class="line"><a name="l01202"></a><span class="lineno"> 1202</span>  RCHECK(VerifyCharacters(buffer, buffer_size, &offset, <span class="charliteral">'-'</span>, 0));</div>
|
|
<div class="line"><a name="l01203"></a><span class="lineno"> 1203</span>  RCHECK(VerifyCharacters(buffer, buffer_size, &offset, <span class="charliteral">'>'</span>, 0));</div>
|
|
<div class="line"><a name="l01204"></a><span class="lineno"> 1204</span>  RCHECK(VerifyCharacters(buffer, buffer_size, &offset, <span class="charliteral">' '</span>, 0));</div>
|
|
<div class="line"><a name="l01205"></a><span class="lineno"> 1205</span>  RCHECK(VerifyNumber(buffer, buffer_size, &offset, 100));</div>
|
|
<div class="line"><a name="l01206"></a><span class="lineno"> 1206</span>  RCHECK(VerifyCharacters(buffer, buffer_size, &offset, <span class="charliteral">':'</span>, 0));</div>
|
|
<div class="line"><a name="l01207"></a><span class="lineno"> 1207</span>  RCHECK(VerifyNumber(buffer, buffer_size, &offset, 2));</div>
|
|
<div class="line"><a name="l01208"></a><span class="lineno"> 1208</span>  RCHECK(VerifyCharacters(buffer, buffer_size, &offset, <span class="charliteral">':'</span>, 0));</div>
|
|
<div class="line"><a name="l01209"></a><span class="lineno"> 1209</span>  RCHECK(VerifyNumber(buffer, buffer_size, &offset, 2));</div>
|
|
<div class="line"><a name="l01210"></a><span class="lineno"> 1210</span>  RCHECK(VerifyCharacters(buffer, buffer_size, &offset, <span class="charliteral">','</span>, <span class="charliteral">'.'</span>));</div>
|
|
<div class="line"><a name="l01211"></a><span class="lineno"> 1211</span>  RCHECK(VerifyNumber(buffer, buffer_size, &offset, 3));</div>
|
|
<div class="line"><a name="l01212"></a><span class="lineno"> 1212</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l01213"></a><span class="lineno"> 1213</span> }</div>
|
|
<div class="line"><a name="l01214"></a><span class="lineno"> 1214</span> </div>
|
|
<div class="line"><a name="l01215"></a><span class="lineno"> 1215</span> <span class="comment">// Read a Matroska Element Id.</span></div>
|
|
<div class="line"><a name="l01216"></a><span class="lineno"> 1216</span> <span class="keyword">static</span> <span class="keywordtype">int</span> GetElementId(BitReader* reader) {</div>
|
|
<div class="line"><a name="l01217"></a><span class="lineno"> 1217</span>  <span class="comment">// Element ID is coded with the leading zero bits (max 3) determining size.</span></div>
|
|
<div class="line"><a name="l01218"></a><span class="lineno"> 1218</span>  <span class="comment">// If it is an invalid encoding or the end of the buffer is reached,</span></div>
|
|
<div class="line"><a name="l01219"></a><span class="lineno"> 1219</span>  <span class="comment">// return -1 as a tag that won't be expected.</span></div>
|
|
<div class="line"><a name="l01220"></a><span class="lineno"> 1220</span>  <span class="keywordflow">if</span> (reader->bits_available() >= 8) {</div>
|
|
<div class="line"><a name="l01221"></a><span class="lineno"> 1221</span>  <span class="keywordtype">int</span> num_bits_to_read = 0;</div>
|
|
<div class="line"><a name="l01222"></a><span class="lineno"> 1222</span>  <span class="keyword">static</span> <span class="keywordtype">int</span> prefix[] = { 0x80, 0x4000, 0x200000, 0x10000000 };</div>
|
|
<div class="line"><a name="l01223"></a><span class="lineno"> 1223</span>  <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i < 4; ++i) {</div>
|
|
<div class="line"><a name="l01224"></a><span class="lineno"> 1224</span>  num_bits_to_read += 7;</div>
|
|
<div class="line"><a name="l01225"></a><span class="lineno"> 1225</span>  <span class="keywordflow">if</span> (ReadBits(reader, 1) == 1) {</div>
|
|
<div class="line"><a name="l01226"></a><span class="lineno"> 1226</span>  <span class="keywordflow">if</span> (static_cast<int>(reader->bits_available()) < num_bits_to_read)</div>
|
|
<div class="line"><a name="l01227"></a><span class="lineno"> 1227</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01228"></a><span class="lineno"> 1228</span>  <span class="comment">// prefix[] adds back the bits read individually.</span></div>
|
|
<div class="line"><a name="l01229"></a><span class="lineno"> 1229</span>  <span class="keywordflow">return</span> ReadBits(reader, num_bits_to_read) | prefix[i];</div>
|
|
<div class="line"><a name="l01230"></a><span class="lineno"> 1230</span>  }</div>
|
|
<div class="line"><a name="l01231"></a><span class="lineno"> 1231</span>  }</div>
|
|
<div class="line"><a name="l01232"></a><span class="lineno"> 1232</span>  }</div>
|
|
<div class="line"><a name="l01233"></a><span class="lineno"> 1233</span>  <span class="comment">// Invalid encoding, return something not expected.</span></div>
|
|
<div class="line"><a name="l01234"></a><span class="lineno"> 1234</span>  <span class="keywordflow">return</span> -1;</div>
|
|
<div class="line"><a name="l01235"></a><span class="lineno"> 1235</span> }</div>
|
|
<div class="line"><a name="l01236"></a><span class="lineno"> 1236</span> </div>
|
|
<div class="line"><a name="l01237"></a><span class="lineno"> 1237</span> <span class="comment">// Read a Matroska Unsigned Integer (VINT).</span></div>
|
|
<div class="line"><a name="l01238"></a><span class="lineno"> 1238</span> <span class="keyword">static</span> uint64_t GetVint(BitReader* reader) {</div>
|
|
<div class="line"><a name="l01239"></a><span class="lineno"> 1239</span>  <span class="comment">// Values are coded with the leading zero bits (max 7) determining size.</span></div>
|
|
<div class="line"><a name="l01240"></a><span class="lineno"> 1240</span>  <span class="comment">// If it is an invalid coding or the end of the buffer is reached,</span></div>
|
|
<div class="line"><a name="l01241"></a><span class="lineno"> 1241</span>  <span class="comment">// return something that will go off the end of the buffer.</span></div>
|
|
<div class="line"><a name="l01242"></a><span class="lineno"> 1242</span>  <span class="keywordflow">if</span> (reader->bits_available() >= 8) {</div>
|
|
<div class="line"><a name="l01243"></a><span class="lineno"> 1243</span>  <span class="keywordtype">int</span> num_bits_to_read = 0;</div>
|
|
<div class="line"><a name="l01244"></a><span class="lineno"> 1244</span>  <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i < 8; ++i) {</div>
|
|
<div class="line"><a name="l01245"></a><span class="lineno"> 1245</span>  num_bits_to_read += 7;</div>
|
|
<div class="line"><a name="l01246"></a><span class="lineno"> 1246</span>  <span class="keywordflow">if</span> (ReadBits(reader, 1) == 1) {</div>
|
|
<div class="line"><a name="l01247"></a><span class="lineno"> 1247</span>  <span class="keywordflow">if</span> (static_cast<int>(reader->bits_available()) < num_bits_to_read)</div>
|
|
<div class="line"><a name="l01248"></a><span class="lineno"> 1248</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01249"></a><span class="lineno"> 1249</span>  <span class="keywordflow">return</span> ReadBits(reader, num_bits_to_read);</div>
|
|
<div class="line"><a name="l01250"></a><span class="lineno"> 1250</span>  }</div>
|
|
<div class="line"><a name="l01251"></a><span class="lineno"> 1251</span>  }</div>
|
|
<div class="line"><a name="l01252"></a><span class="lineno"> 1252</span>  }</div>
|
|
<div class="line"><a name="l01253"></a><span class="lineno"> 1253</span>  <span class="comment">// Incorrect format (more than 7 leading 0's) or off the end of the buffer.</span></div>
|
|
<div class="line"><a name="l01254"></a><span class="lineno"> 1254</span>  <span class="comment">// Since the return value is used as a byte size, return a value that will</span></div>
|
|
<div class="line"><a name="l01255"></a><span class="lineno"> 1255</span>  <span class="comment">// cause a failure when used.</span></div>
|
|
<div class="line"><a name="l01256"></a><span class="lineno"> 1256</span>  <span class="keywordflow">return</span> (reader->bits_available() / 8) + 2;</div>
|
|
<div class="line"><a name="l01257"></a><span class="lineno"> 1257</span> }</div>
|
|
<div class="line"><a name="l01258"></a><span class="lineno"> 1258</span> </div>
|
|
<div class="line"><a name="l01259"></a><span class="lineno"> 1259</span> <span class="comment">// Additional checks for a WEBM container.</span></div>
|
|
<div class="line"><a name="l01260"></a><span class="lineno"> 1260</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckWebm(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l01261"></a><span class="lineno"> 1261</span>  <span class="comment">// Reference: http://www.matroska.org/technical/specs/index.html</span></div>
|
|
<div class="line"><a name="l01262"></a><span class="lineno"> 1262</span>  RCHECK(buffer_size > 12);</div>
|
|
<div class="line"><a name="l01263"></a><span class="lineno"> 1263</span> </div>
|
|
<div class="line"><a name="l01264"></a><span class="lineno"> 1264</span>  BitReader reader(buffer, buffer_size);</div>
|
|
<div class="line"><a name="l01265"></a><span class="lineno"> 1265</span> </div>
|
|
<div class="line"><a name="l01266"></a><span class="lineno"> 1266</span>  <span class="comment">// Verify starting Element Id.</span></div>
|
|
<div class="line"><a name="l01267"></a><span class="lineno"> 1267</span>  RCHECK(GetElementId(&reader) == 0x1a45dfa3);</div>
|
|
<div class="line"><a name="l01268"></a><span class="lineno"> 1268</span> </div>
|
|
<div class="line"><a name="l01269"></a><span class="lineno"> 1269</span>  <span class="comment">// Get the header size, and ensure there are enough bits to check.</span></div>
|
|
<div class="line"><a name="l01270"></a><span class="lineno"> 1270</span>  <span class="keywordtype">int</span> header_size = GetVint(&reader);</div>
|
|
<div class="line"><a name="l01271"></a><span class="lineno"> 1271</span>  RCHECK(static_cast<int>(reader.bits_available()) / 8 >= header_size);</div>
|
|
<div class="line"><a name="l01272"></a><span class="lineno"> 1272</span> </div>
|
|
<div class="line"><a name="l01273"></a><span class="lineno"> 1273</span>  <span class="comment">// Loop through the header.</span></div>
|
|
<div class="line"><a name="l01274"></a><span class="lineno"> 1274</span>  <span class="keywordflow">while</span> (reader.bits_available() > 0) {</div>
|
|
<div class="line"><a name="l01275"></a><span class="lineno"> 1275</span>  <span class="keywordtype">int</span> tag = GetElementId(&reader);</div>
|
|
<div class="line"><a name="l01276"></a><span class="lineno"> 1276</span>  <span class="keywordtype">int</span> tagsize = GetVint(&reader);</div>
|
|
<div class="line"><a name="l01277"></a><span class="lineno"> 1277</span>  <span class="keywordflow">switch</span> (tag) {</div>
|
|
<div class="line"><a name="l01278"></a><span class="lineno"> 1278</span>  <span class="keywordflow">case</span> 0x4286: <span class="comment">// EBMLVersion</span></div>
|
|
<div class="line"><a name="l01279"></a><span class="lineno"> 1279</span>  <span class="keywordflow">case</span> 0x42f7: <span class="comment">// EBMLReadVersion</span></div>
|
|
<div class="line"><a name="l01280"></a><span class="lineno"> 1280</span>  <span class="keywordflow">case</span> 0x42f2: <span class="comment">// EBMLMaxIdLength</span></div>
|
|
<div class="line"><a name="l01281"></a><span class="lineno"> 1281</span>  <span class="keywordflow">case</span> 0x42f3: <span class="comment">// EBMLMaxSizeLength</span></div>
|
|
<div class="line"><a name="l01282"></a><span class="lineno"> 1282</span>  <span class="keywordflow">case</span> 0x4287: <span class="comment">// DocTypeVersion</span></div>
|
|
<div class="line"><a name="l01283"></a><span class="lineno"> 1283</span>  <span class="keywordflow">case</span> 0x4285: <span class="comment">// DocTypeReadVersion</span></div>
|
|
<div class="line"><a name="l01284"></a><span class="lineno"> 1284</span>  <span class="keywordflow">case</span> 0xec: <span class="comment">// void</span></div>
|
|
<div class="line"><a name="l01285"></a><span class="lineno"> 1285</span>  <span class="keywordflow">case</span> 0xbf: <span class="comment">// CRC32</span></div>
|
|
<div class="line"><a name="l01286"></a><span class="lineno"> 1286</span>  RCHECK(reader.SkipBits(tagsize * 8));</div>
|
|
<div class="line"><a name="l01287"></a><span class="lineno"> 1287</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01288"></a><span class="lineno"> 1288</span> </div>
|
|
<div class="line"><a name="l01289"></a><span class="lineno"> 1289</span>  <span class="keywordflow">case</span> 0x4282: <span class="comment">// EBMLDocType</span></div>
|
|
<div class="line"><a name="l01290"></a><span class="lineno"> 1290</span>  <span class="comment">// Need to see "webm" or "matroska" next.</span></div>
|
|
<div class="line"><a name="l01291"></a><span class="lineno"> 1291</span>  <span class="keywordflow">switch</span> (ReadBits(&reader, 32)) {</div>
|
|
<div class="line"><a name="l01292"></a><span class="lineno"> 1292</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'w'</span>, <span class="charliteral">'e'</span>, <span class="charliteral">'b'</span>, <span class="charliteral">'m'</span>) :</div>
|
|
<div class="line"><a name="l01293"></a><span class="lineno"> 1293</span>  return true;</div>
|
|
<div class="line"><a name="l01294"></a><span class="lineno"> 1294</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'m'</span>, <span class="charliteral">'a'</span>, <span class="charliteral">'t'</span>, <span class="charliteral">'r'</span>) :</div>
|
|
<div class="line"><a name="l01295"></a><span class="lineno"> 1295</span>  return (ReadBits(&reader, 32) == TAG(<span class="stringliteral">'o'</span>, <span class="stringliteral">'s'</span>, <span class="stringliteral">'k'</span>, <span class="stringliteral">'a'</span>));</div>
|
|
<div class="line"><a name="l01296"></a><span class="lineno"> 1296</span>  }</div>
|
|
<div class="line"><a name="l01297"></a><span class="lineno"> 1297</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l01298"></a><span class="lineno"> 1298</span> </div>
|
|
<div class="line"><a name="l01299"></a><span class="lineno"> 1299</span>  <span class="keywordflow">default</span>: <span class="comment">// Unrecognized tag</span></div>
|
|
<div class="line"><a name="l01300"></a><span class="lineno"> 1300</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l01301"></a><span class="lineno"> 1301</span>  }</div>
|
|
<div class="line"><a name="l01302"></a><span class="lineno"> 1302</span>  }</div>
|
|
<div class="line"><a name="l01303"></a><span class="lineno"> 1303</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l01304"></a><span class="lineno"> 1304</span> }</div>
|
|
<div class="line"><a name="l01305"></a><span class="lineno"> 1305</span> </div>
|
|
<div class="line"><a name="l01306"></a><span class="lineno"> 1306</span> <span class="keyword">enum</span> VC1StartCodes {</div>
|
|
<div class="line"><a name="l01307"></a><span class="lineno"> 1307</span>  VC1_FRAME_START_CODE = 0x0d,</div>
|
|
<div class="line"><a name="l01308"></a><span class="lineno"> 1308</span>  VC1_ENTRY_POINT_START_CODE = 0x0e,</div>
|
|
<div class="line"><a name="l01309"></a><span class="lineno"> 1309</span>  VC1_SEQUENCE_START_CODE = 0x0f</div>
|
|
<div class="line"><a name="l01310"></a><span class="lineno"> 1310</span> };</div>
|
|
<div class="line"><a name="l01311"></a><span class="lineno"> 1311</span> </div>
|
|
<div class="line"><a name="l01312"></a><span class="lineno"> 1312</span> <span class="comment">// Checks for a VC1 bitstream container.</span></div>
|
|
<div class="line"><a name="l01313"></a><span class="lineno"> 1313</span> <span class="keyword">static</span> <span class="keywordtype">bool</span> CheckVC1(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l01314"></a><span class="lineno"> 1314</span>  <span class="comment">// Reference: SMPTE 421M</span></div>
|
|
<div class="line"><a name="l01315"></a><span class="lineno"> 1315</span>  <span class="comment">// (http://standards.smpte.org/content/978-1-61482-555-5/st-421-2006/SEC1.body.pdf)</span></div>
|
|
<div class="line"><a name="l01316"></a><span class="lineno"> 1316</span>  <span class="comment">// However, no length ... simply scan for start code values.</span></div>
|
|
<div class="line"><a name="l01317"></a><span class="lineno"> 1317</span>  <span class="comment">// Expect to see SEQ | [ [ ENTRY ] PIC* ]*</span></div>
|
|
<div class="line"><a name="l01318"></a><span class="lineno"> 1318</span>  <span class="comment">// Note tags are very similar to H.264.</span></div>
|
|
<div class="line"><a name="l01319"></a><span class="lineno"> 1319</span> </div>
|
|
<div class="line"><a name="l01320"></a><span class="lineno"> 1320</span>  RCHECK(buffer_size >= 24);</div>
|
|
<div class="line"><a name="l01321"></a><span class="lineno"> 1321</span> </div>
|
|
<div class="line"><a name="l01322"></a><span class="lineno"> 1322</span>  <span class="comment">// First check for Bitstream Metadata Serialization (Annex L)</span></div>
|
|
<div class="line"><a name="l01323"></a><span class="lineno"> 1323</span>  <span class="keywordflow">if</span> (buffer[0] == 0xc5 &&</div>
|
|
<div class="line"><a name="l01324"></a><span class="lineno"> 1324</span>  Read32(buffer + 4) == 0x04 &&</div>
|
|
<div class="line"><a name="l01325"></a><span class="lineno"> 1325</span>  Read32(buffer + 20) == 0x0c) {</div>
|
|
<div class="line"><a name="l01326"></a><span class="lineno"> 1326</span>  <span class="comment">// Verify settings in STRUCT_C and STRUCT_A</span></div>
|
|
<div class="line"><a name="l01327"></a><span class="lineno"> 1327</span>  BitReader reader(buffer + 8, 12);</div>
|
|
<div class="line"><a name="l01328"></a><span class="lineno"> 1328</span> </div>
|
|
<div class="line"><a name="l01329"></a><span class="lineno"> 1329</span>  <span class="keywordtype">int</span> profile = ReadBits(&reader, 4);</div>
|
|
<div class="line"><a name="l01330"></a><span class="lineno"> 1330</span>  <span class="keywordflow">if</span> (profile == 0 || profile == 4) { <span class="comment">// simple or main</span></div>
|
|
<div class="line"><a name="l01331"></a><span class="lineno"> 1331</span>  <span class="comment">// Skip FRMRTQ_POSTPROC, BITRTQ_POSTPROC, and LOOPFILTER.</span></div>
|
|
<div class="line"><a name="l01332"></a><span class="lineno"> 1332</span>  reader.SkipBits(3 + 5 + 1);</div>
|
|
<div class="line"><a name="l01333"></a><span class="lineno"> 1333</span> </div>
|
|
<div class="line"><a name="l01334"></a><span class="lineno"> 1334</span>  <span class="comment">// Next bit must be 0.</span></div>
|
|
<div class="line"><a name="l01335"></a><span class="lineno"> 1335</span>  RCHECK(ReadBits(&reader, 1) == 0);</div>
|
|
<div class="line"><a name="l01336"></a><span class="lineno"> 1336</span> </div>
|
|
<div class="line"><a name="l01337"></a><span class="lineno"> 1337</span>  <span class="comment">// Skip MULTIRES.</span></div>
|
|
<div class="line"><a name="l01338"></a><span class="lineno"> 1338</span>  reader.SkipBits(1);</div>
|
|
<div class="line"><a name="l01339"></a><span class="lineno"> 1339</span> </div>
|
|
<div class="line"><a name="l01340"></a><span class="lineno"> 1340</span>  <span class="comment">// Next bit must be 1.</span></div>
|
|
<div class="line"><a name="l01341"></a><span class="lineno"> 1341</span>  RCHECK(ReadBits(&reader, 1) == 1);</div>
|
|
<div class="line"><a name="l01342"></a><span class="lineno"> 1342</span> </div>
|
|
<div class="line"><a name="l01343"></a><span class="lineno"> 1343</span>  <span class="comment">// Skip FASTUVMC, EXTENDED_MV, DQUANT, and VSTRANSFORM.</span></div>
|
|
<div class="line"><a name="l01344"></a><span class="lineno"> 1344</span>  reader.SkipBits(1 + 1 + 2 + 1);</div>
|
|
<div class="line"><a name="l01345"></a><span class="lineno"> 1345</span> </div>
|
|
<div class="line"><a name="l01346"></a><span class="lineno"> 1346</span>  <span class="comment">// Next bit must be 0.</span></div>
|
|
<div class="line"><a name="l01347"></a><span class="lineno"> 1347</span>  RCHECK(ReadBits(&reader, 1) == 0);</div>
|
|
<div class="line"><a name="l01348"></a><span class="lineno"> 1348</span> </div>
|
|
<div class="line"><a name="l01349"></a><span class="lineno"> 1349</span>  <span class="comment">// Skip OVERLAP, SYNCMARKER, RANGERED, MAXBFRAMES, QUANTIZER, and</span></div>
|
|
<div class="line"><a name="l01350"></a><span class="lineno"> 1350</span>  <span class="comment">// FINTERPFLAG.</span></div>
|
|
<div class="line"><a name="l01351"></a><span class="lineno"> 1351</span>  reader.SkipBits(1 + 1 + 1 + 3 + 2 + 1);</div>
|
|
<div class="line"><a name="l01352"></a><span class="lineno"> 1352</span> </div>
|
|
<div class="line"><a name="l01353"></a><span class="lineno"> 1353</span>  <span class="comment">// Next bit must be 1.</span></div>
|
|
<div class="line"><a name="l01354"></a><span class="lineno"> 1354</span>  RCHECK(ReadBits(&reader, 1) == 1);</div>
|
|
<div class="line"><a name="l01355"></a><span class="lineno"> 1355</span> </div>
|
|
<div class="line"><a name="l01356"></a><span class="lineno"> 1356</span>  } <span class="keywordflow">else</span> {</div>
|
|
<div class="line"><a name="l01357"></a><span class="lineno"> 1357</span>  RCHECK(profile == 12); <span class="comment">// Other profile values not allowed.</span></div>
|
|
<div class="line"><a name="l01358"></a><span class="lineno"> 1358</span>  RCHECK(ReadBits(&reader, 28) == 0);</div>
|
|
<div class="line"><a name="l01359"></a><span class="lineno"> 1359</span>  }</div>
|
|
<div class="line"><a name="l01360"></a><span class="lineno"> 1360</span> </div>
|
|
<div class="line"><a name="l01361"></a><span class="lineno"> 1361</span>  <span class="comment">// Now check HORIZ_SIZE and VERT_SIZE, which must be 8192 or less.</span></div>
|
|
<div class="line"><a name="l01362"></a><span class="lineno"> 1362</span>  RCHECK(ReadBits(&reader, 32) <= 8192);</div>
|
|
<div class="line"><a name="l01363"></a><span class="lineno"> 1363</span>  RCHECK(ReadBits(&reader, 32) <= 8192);</div>
|
|
<div class="line"><a name="l01364"></a><span class="lineno"> 1364</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l01365"></a><span class="lineno"> 1365</span>  }</div>
|
|
<div class="line"><a name="l01366"></a><span class="lineno"> 1366</span> </div>
|
|
<div class="line"><a name="l01367"></a><span class="lineno"> 1367</span>  <span class="comment">// Buffer isn't Bitstream Metadata, so scan for start codes.</span></div>
|
|
<div class="line"><a name="l01368"></a><span class="lineno"> 1368</span>  <span class="keywordtype">int</span> offset = 0;</div>
|
|
<div class="line"><a name="l01369"></a><span class="lineno"> 1369</span>  <span class="keywordtype">int</span> sequence_start_code = 0;</div>
|
|
<div class="line"><a name="l01370"></a><span class="lineno"> 1370</span>  <span class="keywordtype">int</span> frame_start_code = 0;</div>
|
|
<div class="line"><a name="l01371"></a><span class="lineno"> 1371</span>  <span class="keywordflow">while</span> (<span class="keyword">true</span>) {</div>
|
|
<div class="line"><a name="l01372"></a><span class="lineno"> 1372</span>  <span class="comment">// Advance to start_code, if there is one.</span></div>
|
|
<div class="line"><a name="l01373"></a><span class="lineno"> 1373</span>  <span class="keywordflow">if</span> (!AdvanceToStartCode(buffer, buffer_size, &offset, 5, 24, 1)) {</div>
|
|
<div class="line"><a name="l01374"></a><span class="lineno"> 1374</span>  <span class="comment">// Not a complete sequence in memory, so return true if we've seen a</span></div>
|
|
<div class="line"><a name="l01375"></a><span class="lineno"> 1375</span>  <span class="comment">// sequence start and a frame start (not checking entry points since</span></div>
|
|
<div class="line"><a name="l01376"></a><span class="lineno"> 1376</span>  <span class="comment">// they only occur in advanced profiles).</span></div>
|
|
<div class="line"><a name="l01377"></a><span class="lineno"> 1377</span>  <span class="keywordflow">return</span> (sequence_start_code > 0 && frame_start_code > 0);</div>
|
|
<div class="line"><a name="l01378"></a><span class="lineno"> 1378</span>  }</div>
|
|
<div class="line"><a name="l01379"></a><span class="lineno"> 1379</span> </div>
|
|
<div class="line"><a name="l01380"></a><span class="lineno"> 1380</span>  <span class="comment">// Now verify the block. AdvanceToStartCode() made sure that there are</span></div>
|
|
<div class="line"><a name="l01381"></a><span class="lineno"> 1381</span>  <span class="comment">// at least 5 bytes remaining in the buffer.</span></div>
|
|
<div class="line"><a name="l01382"></a><span class="lineno"> 1382</span>  BitReader reader(buffer + offset, 5);</div>
|
|
<div class="line"><a name="l01383"></a><span class="lineno"> 1383</span>  RCHECK(ReadBits(&reader, 24) == 1);</div>
|
|
<div class="line"><a name="l01384"></a><span class="lineno"> 1384</span> </div>
|
|
<div class="line"><a name="l01385"></a><span class="lineno"> 1385</span>  <span class="comment">// Keep track of the number of certain types received.</span></div>
|
|
<div class="line"><a name="l01386"></a><span class="lineno"> 1386</span>  <span class="keywordflow">switch</span> (ReadBits(&reader, 8)) {</div>
|
|
<div class="line"><a name="l01387"></a><span class="lineno"> 1387</span>  <span class="keywordflow">case</span> VC1_SEQUENCE_START_CODE: {</div>
|
|
<div class="line"><a name="l01388"></a><span class="lineno"> 1388</span>  ++sequence_start_code;</div>
|
|
<div class="line"><a name="l01389"></a><span class="lineno"> 1389</span>  <span class="keywordflow">switch</span> (ReadBits(&reader, 2)) {</div>
|
|
<div class="line"><a name="l01390"></a><span class="lineno"> 1390</span>  <span class="keywordflow">case</span> 0: <span class="comment">// simple</span></div>
|
|
<div class="line"><a name="l01391"></a><span class="lineno"> 1391</span>  <span class="keywordflow">case</span> 1: <span class="comment">// main</span></div>
|
|
<div class="line"><a name="l01392"></a><span class="lineno"> 1392</span>  RCHECK(ReadBits(&reader, 2) == 0);</div>
|
|
<div class="line"><a name="l01393"></a><span class="lineno"> 1393</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01394"></a><span class="lineno"> 1394</span>  <span class="keywordflow">case</span> 2: <span class="comment">// complex</span></div>
|
|
<div class="line"><a name="l01395"></a><span class="lineno"> 1395</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l01396"></a><span class="lineno"> 1396</span>  <span class="keywordflow">case</span> 3: <span class="comment">// advanced</span></div>
|
|
<div class="line"><a name="l01397"></a><span class="lineno"> 1397</span>  RCHECK(ReadBits(&reader, 3) <= 4); <span class="comment">// Verify level = 0..4</span></div>
|
|
<div class="line"><a name="l01398"></a><span class="lineno"> 1398</span>  RCHECK(ReadBits(&reader, 2) == 1); <span class="comment">// Verify colordiff_format = 1</span></div>
|
|
<div class="line"><a name="l01399"></a><span class="lineno"> 1399</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01400"></a><span class="lineno"> 1400</span>  }</div>
|
|
<div class="line"><a name="l01401"></a><span class="lineno"> 1401</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01402"></a><span class="lineno"> 1402</span>  }</div>
|
|
<div class="line"><a name="l01403"></a><span class="lineno"> 1403</span> </div>
|
|
<div class="line"><a name="l01404"></a><span class="lineno"> 1404</span>  <span class="keywordflow">case</span> VC1_ENTRY_POINT_START_CODE:</div>
|
|
<div class="line"><a name="l01405"></a><span class="lineno"> 1405</span>  <span class="comment">// No fields in entry data to check. However, it must occur after</span></div>
|
|
<div class="line"><a name="l01406"></a><span class="lineno"> 1406</span>  <span class="comment">// sequence header.</span></div>
|
|
<div class="line"><a name="l01407"></a><span class="lineno"> 1407</span>  RCHECK(sequence_start_code > 0);</div>
|
|
<div class="line"><a name="l01408"></a><span class="lineno"> 1408</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01409"></a><span class="lineno"> 1409</span> </div>
|
|
<div class="line"><a name="l01410"></a><span class="lineno"> 1410</span>  <span class="keywordflow">case</span> VC1_FRAME_START_CODE:</div>
|
|
<div class="line"><a name="l01411"></a><span class="lineno"> 1411</span>  ++frame_start_code;</div>
|
|
<div class="line"><a name="l01412"></a><span class="lineno"> 1412</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01413"></a><span class="lineno"> 1413</span>  }</div>
|
|
<div class="line"><a name="l01414"></a><span class="lineno"> 1414</span>  offset += 5;</div>
|
|
<div class="line"><a name="l01415"></a><span class="lineno"> 1415</span>  }</div>
|
|
<div class="line"><a name="l01416"></a><span class="lineno"> 1416</span> }</div>
|
|
<div class="line"><a name="l01417"></a><span class="lineno"> 1417</span> </div>
|
|
<div class="line"><a name="l01418"></a><span class="lineno"> 1418</span> <span class="comment">// For some formats the signature is a bunch of characters. They are defined</span></div>
|
|
<div class="line"><a name="l01419"></a><span class="lineno"> 1419</span> <span class="comment">// below. Note that the first 4 characters of the string may be used as a TAG</span></div>
|
|
<div class="line"><a name="l01420"></a><span class="lineno"> 1420</span> <span class="comment">// in LookupContainerByFirst4. For signatures that contain embedded \0, use</span></div>
|
|
<div class="line"><a name="l01421"></a><span class="lineno"> 1421</span> <span class="comment">// uint8_t[].</span></div>
|
|
<div class="line"><a name="l01422"></a><span class="lineno"> 1422</span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">char</span> kAmrSignature[] = <span class="stringliteral">"#!AMR"</span>;</div>
|
|
<div class="line"><a name="l01423"></a><span class="lineno"> 1423</span> <span class="keyword">static</span> <span class="keyword">const</span> uint8_t kAsfSignature[] = {0x30, 0x26, 0xb2, 0x75, 0x8e, 0x66,</div>
|
|
<div class="line"><a name="l01424"></a><span class="lineno"> 1424</span>  0xcf, 0x11, 0xa6, 0xd9, 0x00, 0xaa,</div>
|
|
<div class="line"><a name="l01425"></a><span class="lineno"> 1425</span>  0x00, 0x62, 0xce, 0x6c};</div>
|
|
<div class="line"><a name="l01426"></a><span class="lineno"> 1426</span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">char</span> kAssSignature[] = <span class="stringliteral">"[Script Info]"</span>;</div>
|
|
<div class="line"><a name="l01427"></a><span class="lineno"> 1427</span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">char</span> kAssBomSignature[] = UTF8_BYTE_ORDER_MARK <span class="stringliteral">"[Script Info]"</span>;</div>
|
|
<div class="line"><a name="l01428"></a><span class="lineno"> 1428</span> <span class="keyword">static</span> <span class="keyword">const</span> uint8_t kWtvSignature[] = {0xb7, 0xd8, 0x00, 0x20, 0x37, 0x49,</div>
|
|
<div class="line"><a name="l01429"></a><span class="lineno"> 1429</span>  0xda, 0x11, 0xa6, 0x4e, 0x00, 0x07,</div>
|
|
<div class="line"><a name="l01430"></a><span class="lineno"> 1430</span>  0xe9, 0x5e, 0xad, 0x8d};</div>
|
|
<div class="line"><a name="l01431"></a><span class="lineno"> 1431</span> </div>
|
|
<div class="line"><a name="l01432"></a><span class="lineno"> 1432</span> <span class="comment">// Attempt to determine the container type from the buffer provided. This is</span></div>
|
|
<div class="line"><a name="l01433"></a><span class="lineno"> 1433</span> <span class="comment">// a simple pass, that uses the first 4 bytes of the buffer as an index to get</span></div>
|
|
<div class="line"><a name="l01434"></a><span class="lineno"> 1434</span> <span class="comment">// a rough idea of the container format.</span></div>
|
|
<div class="line"><a name="l01435"></a><span class="lineno"> 1435</span> <span class="keyword">static</span> MediaContainerName LookupContainerByFirst4(<span class="keyword">const</span> uint8_t* buffer,</div>
|
|
<div class="line"><a name="l01436"></a><span class="lineno"> 1436</span>  <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l01437"></a><span class="lineno"> 1437</span>  <span class="comment">// Minimum size that the code expects to exist without checking size.</span></div>
|
|
<div class="line"><a name="l01438"></a><span class="lineno"> 1438</span>  <span class="keywordflow">if</span> (buffer_size < 12)</div>
|
|
<div class="line"><a name="l01439"></a><span class="lineno"> 1439</span>  <span class="keywordflow">return</span> CONTAINER_UNKNOWN;</div>
|
|
<div class="line"><a name="l01440"></a><span class="lineno"> 1440</span> </div>
|
|
<div class="line"><a name="l01441"></a><span class="lineno"> 1441</span>  uint32_t first4 = Read32(buffer);</div>
|
|
<div class="line"><a name="l01442"></a><span class="lineno"> 1442</span>  <span class="keywordflow">switch</span> (first4) {</div>
|
|
<div class="line"><a name="l01443"></a><span class="lineno"> 1443</span>  <span class="keywordflow">case</span> 0x1a45dfa3:</div>
|
|
<div class="line"><a name="l01444"></a><span class="lineno"> 1444</span>  <span class="keywordflow">if</span> (CheckWebm(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01445"></a><span class="lineno"> 1445</span>  <span class="keywordflow">return</span> CONTAINER_WEBM;</div>
|
|
<div class="line"><a name="l01446"></a><span class="lineno"> 1446</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01447"></a><span class="lineno"> 1447</span> </div>
|
|
<div class="line"><a name="l01448"></a><span class="lineno"> 1448</span>  <span class="keywordflow">case</span> 0x3026b275:</div>
|
|
<div class="line"><a name="l01449"></a><span class="lineno"> 1449</span>  <span class="keywordflow">if</span> (StartsWith(buffer,</div>
|
|
<div class="line"><a name="l01450"></a><span class="lineno"> 1450</span>  buffer_size,</div>
|
|
<div class="line"><a name="l01451"></a><span class="lineno"> 1451</span>  kAsfSignature,</div>
|
|
<div class="line"><a name="l01452"></a><span class="lineno"> 1452</span>  <span class="keyword">sizeof</span>(kAsfSignature))) {</div>
|
|
<div class="line"><a name="l01453"></a><span class="lineno"> 1453</span>  <span class="keywordflow">return</span> CONTAINER_ASF;</div>
|
|
<div class="line"><a name="l01454"></a><span class="lineno"> 1454</span>  }</div>
|
|
<div class="line"><a name="l01455"></a><span class="lineno"> 1455</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01456"></a><span class="lineno"> 1456</span> </div>
|
|
<div class="line"><a name="l01457"></a><span class="lineno"> 1457</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'#'</span>,<span class="charliteral">'!'</span>,<span class="charliteral">'A'</span>,<span class="charliteral">'M'</span>):</div>
|
|
<div class="line"><a name="l01458"></a><span class="lineno"> 1458</span>  if (StartsWith(buffer, buffer_size, kAmrSignature))</div>
|
|
<div class="line"><a name="l01459"></a><span class="lineno"> 1459</span>  return CONTAINER_AMR;</div>
|
|
<div class="line"><a name="l01460"></a><span class="lineno"> 1460</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01461"></a><span class="lineno"> 1461</span> </div>
|
|
<div class="line"><a name="l01462"></a><span class="lineno"> 1462</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'#'</span>,<span class="charliteral">'E'</span>,<span class="charliteral">'X'</span>,<span class="charliteral">'T'</span>):</div>
|
|
<div class="line"><a name="l01463"></a><span class="lineno"> 1463</span>  if (CheckHls(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01464"></a><span class="lineno"> 1464</span>  return CONTAINER_HLS;</div>
|
|
<div class="line"><a name="l01465"></a><span class="lineno"> 1465</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01466"></a><span class="lineno"> 1466</span> </div>
|
|
<div class="line"><a name="l01467"></a><span class="lineno"> 1467</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'.'</span>,<span class="charliteral">'R'</span>,<span class="charliteral">'M'</span>,<span class="charliteral">'F'</span>):</div>
|
|
<div class="line"><a name="l01468"></a><span class="lineno"> 1468</span>  if (buffer[4] == 0 && buffer[5] == 0)</div>
|
|
<div class="line"><a name="l01469"></a><span class="lineno"> 1469</span>  return CONTAINER_RM;</div>
|
|
<div class="line"><a name="l01470"></a><span class="lineno"> 1470</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01471"></a><span class="lineno"> 1471</span> </div>
|
|
<div class="line"><a name="l01472"></a><span class="lineno"> 1472</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'.'</span>,<span class="charliteral">'r'</span>,<span class="charliteral">'a'</span>,<span class="stringliteral">'\xfd'</span>):</div>
|
|
<div class="line"><a name="l01473"></a><span class="lineno"> 1473</span>  return CONTAINER_RM;</div>
|
|
<div class="line"><a name="l01474"></a><span class="lineno"> 1474</span> </div>
|
|
<div class="line"><a name="l01475"></a><span class="lineno"> 1475</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'B'</span>,<span class="charliteral">'I'</span>,<span class="charliteral">'K'</span>,<span class="charliteral">'b'</span>):</div>
|
|
<div class="line"><a name="l01476"></a><span class="lineno"> 1476</span>  case TAG(<span class="stringliteral">'B'</span>,<span class="stringliteral">'I'</span>,<span class="stringliteral">'K'</span>,<span class="stringliteral">'d'</span>):</div>
|
|
<div class="line"><a name="l01477"></a><span class="lineno"> 1477</span>  case TAG(<span class="stringliteral">'B'</span>,<span class="stringliteral">'I'</span>,<span class="stringliteral">'K'</span>,<span class="stringliteral">'f'</span>):</div>
|
|
<div class="line"><a name="l01478"></a><span class="lineno"> 1478</span>  case TAG(<span class="stringliteral">'B'</span>,<span class="stringliteral">'I'</span>,<span class="stringliteral">'K'</span>,<span class="stringliteral">'g'</span>):</div>
|
|
<div class="line"><a name="l01479"></a><span class="lineno"> 1479</span>  case TAG(<span class="stringliteral">'B'</span>,<span class="stringliteral">'I'</span>,<span class="stringliteral">'K'</span>,<span class="stringliteral">'h'</span>):</div>
|
|
<div class="line"><a name="l01480"></a><span class="lineno"> 1480</span>  case TAG(<span class="stringliteral">'B'</span>,<span class="stringliteral">'I'</span>,<span class="stringliteral">'K'</span>,<span class="stringliteral">'i'</span>):</div>
|
|
<div class="line"><a name="l01481"></a><span class="lineno"> 1481</span>  if (CheckBink(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01482"></a><span class="lineno"> 1482</span>  return CONTAINER_BINK;</div>
|
|
<div class="line"><a name="l01483"></a><span class="lineno"> 1483</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01484"></a><span class="lineno"> 1484</span> </div>
|
|
<div class="line"><a name="l01485"></a><span class="lineno"> 1485</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'c'</span>,<span class="charliteral">'a'</span>,<span class="charliteral">'f'</span>,<span class="charliteral">'f'</span>):</div>
|
|
<div class="line"><a name="l01486"></a><span class="lineno"> 1486</span>  if (CheckCaf(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01487"></a><span class="lineno"> 1487</span>  return CONTAINER_CAF;</div>
|
|
<div class="line"><a name="l01488"></a><span class="lineno"> 1488</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01489"></a><span class="lineno"> 1489</span> </div>
|
|
<div class="line"><a name="l01490"></a><span class="lineno"> 1490</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'D'</span>,<span class="charliteral">'E'</span>,<span class="charliteral">'X'</span>,<span class="charliteral">'A'</span>):</div>
|
|
<div class="line"><a name="l01491"></a><span class="lineno"> 1491</span>  if (buffer_size > 15 &&</div>
|
|
<div class="line"><a name="l01492"></a><span class="lineno"> 1492</span>  Read16(buffer + 11) <= 2048 &&</div>
|
|
<div class="line"><a name="l01493"></a><span class="lineno"> 1493</span>  Read16(buffer + 13) <= 2048) {</div>
|
|
<div class="line"><a name="l01494"></a><span class="lineno"> 1494</span>  <span class="keywordflow">return</span> CONTAINER_DXA;</div>
|
|
<div class="line"><a name="l01495"></a><span class="lineno"> 1495</span>  }</div>
|
|
<div class="line"><a name="l01496"></a><span class="lineno"> 1496</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01497"></a><span class="lineno"> 1497</span> </div>
|
|
<div class="line"><a name="l01498"></a><span class="lineno"> 1498</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'D'</span>,<span class="charliteral">'T'</span>,<span class="charliteral">'S'</span>,<span class="charliteral">'H'</span>):</div>
|
|
<div class="line"><a name="l01499"></a><span class="lineno"> 1499</span>  if (Read32(buffer + 4) == TAG(<span class="stringliteral">'D'</span>,<span class="stringliteral">'H'</span>,<span class="stringliteral">'D'</span>,<span class="stringliteral">'R'</span>))</div>
|
|
<div class="line"><a name="l01500"></a><span class="lineno"> 1500</span>  return CONTAINER_DTSHD;</div>
|
|
<div class="line"><a name="l01501"></a><span class="lineno"> 1501</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01502"></a><span class="lineno"> 1502</span> </div>
|
|
<div class="line"><a name="l01503"></a><span class="lineno"> 1503</span>  <span class="keywordflow">case</span> 0x64a30100:</div>
|
|
<div class="line"><a name="l01504"></a><span class="lineno"> 1504</span>  <span class="keywordflow">case</span> 0x64a30200:</div>
|
|
<div class="line"><a name="l01505"></a><span class="lineno"> 1505</span>  <span class="keywordflow">case</span> 0x64a30300:</div>
|
|
<div class="line"><a name="l01506"></a><span class="lineno"> 1506</span>  <span class="keywordflow">case</span> 0x64a30400:</div>
|
|
<div class="line"><a name="l01507"></a><span class="lineno"> 1507</span>  <span class="keywordflow">case</span> 0x0001a364:</div>
|
|
<div class="line"><a name="l01508"></a><span class="lineno"> 1508</span>  <span class="keywordflow">case</span> 0x0002a364:</div>
|
|
<div class="line"><a name="l01509"></a><span class="lineno"> 1509</span>  <span class="keywordflow">case</span> 0x0003a364:</div>
|
|
<div class="line"><a name="l01510"></a><span class="lineno"> 1510</span>  <span class="keywordflow">if</span> (Read32(buffer + 4) != 0 && Read32(buffer + 8) != 0)</div>
|
|
<div class="line"><a name="l01511"></a><span class="lineno"> 1511</span>  <span class="keywordflow">return</span> CONTAINER_IRCAM;</div>
|
|
<div class="line"><a name="l01512"></a><span class="lineno"> 1512</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01513"></a><span class="lineno"> 1513</span> </div>
|
|
<div class="line"><a name="l01514"></a><span class="lineno"> 1514</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'f'</span>,<span class="charliteral">'L'</span>,<span class="charliteral">'a'</span>,<span class="charliteral">'C'</span>):</div>
|
|
<div class="line"><a name="l01515"></a><span class="lineno"> 1515</span>  return CONTAINER_FLAC;</div>
|
|
<div class="line"><a name="l01516"></a><span class="lineno"> 1516</span> </div>
|
|
<div class="line"><a name="l01517"></a><span class="lineno"> 1517</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'F'</span>,<span class="charliteral">'L'</span>,<span class="charliteral">'V'</span>,0):</div>
|
|
<div class="line"><a name="l01518"></a><span class="lineno"> 1518</span>  case TAG(<span class="stringliteral">'F'</span>,<span class="stringliteral">'L'</span>,<span class="stringliteral">'V'</span>,1):</div>
|
|
<div class="line"><a name="l01519"></a><span class="lineno"> 1519</span>  case TAG(<span class="stringliteral">'F'</span>,<span class="stringliteral">'L'</span>,<span class="stringliteral">'V'</span>,2):</div>
|
|
<div class="line"><a name="l01520"></a><span class="lineno"> 1520</span>  case TAG(<span class="stringliteral">'F'</span>,<span class="stringliteral">'L'</span>,<span class="stringliteral">'V'</span>,3):</div>
|
|
<div class="line"><a name="l01521"></a><span class="lineno"> 1521</span>  case TAG(<span class="stringliteral">'F'</span>,<span class="stringliteral">'L'</span>,<span class="stringliteral">'V'</span>,4):</div>
|
|
<div class="line"><a name="l01522"></a><span class="lineno"> 1522</span>  if (buffer[5] == 0 && Read32(buffer + 5) > 8)</div>
|
|
<div class="line"><a name="l01523"></a><span class="lineno"> 1523</span>  return CONTAINER_FLV;</div>
|
|
<div class="line"><a name="l01524"></a><span class="lineno"> 1524</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01525"></a><span class="lineno"> 1525</span> </div>
|
|
<div class="line"><a name="l01526"></a><span class="lineno"> 1526</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'F'</span>,<span class="charliteral">'O'</span>,<span class="charliteral">'R'</span>,<span class="charliteral">'M'</span>):</div>
|
|
<div class="line"><a name="l01527"></a><span class="lineno"> 1527</span>  switch (Read32(buffer + 8)) {</div>
|
|
<div class="line"><a name="l01528"></a><span class="lineno"> 1528</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'A'</span>,<span class="charliteral">'I'</span>,<span class="charliteral">'F'</span>,<span class="charliteral">'F'</span>):</div>
|
|
<div class="line"><a name="l01529"></a><span class="lineno"> 1529</span>  case TAG(<span class="stringliteral">'A'</span>,<span class="stringliteral">'I'</span>,<span class="stringliteral">'F'</span>,<span class="stringliteral">'C'</span>):</div>
|
|
<div class="line"><a name="l01530"></a><span class="lineno"> 1530</span>  return CONTAINER_AIFF;</div>
|
|
<div class="line"><a name="l01531"></a><span class="lineno"> 1531</span>  }</div>
|
|
<div class="line"><a name="l01532"></a><span class="lineno"> 1532</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01533"></a><span class="lineno"> 1533</span> </div>
|
|
<div class="line"><a name="l01534"></a><span class="lineno"> 1534</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'M'</span>,<span class="charliteral">'A'</span>,<span class="charliteral">'C'</span>,<span class="charliteral">' '</span>):</div>
|
|
<div class="line"><a name="l01535"></a><span class="lineno"> 1535</span>  return CONTAINER_APE;</div>
|
|
<div class="line"><a name="l01536"></a><span class="lineno"> 1536</span> </div>
|
|
<div class="line"><a name="l01537"></a><span class="lineno"> 1537</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'O'</span>,<span class="charliteral">'N'</span>,<span class="charliteral">'2'</span>,<span class="charliteral">' '</span>):</div>
|
|
<div class="line"><a name="l01538"></a><span class="lineno"> 1538</span>  if (Read32(buffer + 8) == TAG(<span class="stringliteral">'O'</span>,<span class="stringliteral">'N'</span>,<span class="stringliteral">'2'</span>,<span class="stringliteral">'f'</span>))</div>
|
|
<div class="line"><a name="l01539"></a><span class="lineno"> 1539</span>  return CONTAINER_AVI;</div>
|
|
<div class="line"><a name="l01540"></a><span class="lineno"> 1540</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01541"></a><span class="lineno"> 1541</span> </div>
|
|
<div class="line"><a name="l01542"></a><span class="lineno"> 1542</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'O'</span>,<span class="charliteral">'g'</span>,<span class="charliteral">'g'</span>,<span class="charliteral">'S'</span>):</div>
|
|
<div class="line"><a name="l01543"></a><span class="lineno"> 1543</span>  if (buffer[5] <= 7)</div>
|
|
<div class="line"><a name="l01544"></a><span class="lineno"> 1544</span>  return CONTAINER_OGG;</div>
|
|
<div class="line"><a name="l01545"></a><span class="lineno"> 1545</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01546"></a><span class="lineno"> 1546</span> </div>
|
|
<div class="line"><a name="l01547"></a><span class="lineno"> 1547</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'R'</span>,<span class="charliteral">'F'</span>,<span class="charliteral">'6'</span>,<span class="charliteral">'4'</span>):</div>
|
|
<div class="line"><a name="l01548"></a><span class="lineno"> 1548</span>  if (buffer_size > 16 && Read32(buffer + 12) == TAG(<span class="stringliteral">'d'</span>,<span class="stringliteral">'s'</span>,<span class="stringliteral">'6'</span>,<span class="stringliteral">'4'</span>))</div>
|
|
<div class="line"><a name="l01549"></a><span class="lineno"> 1549</span>  return CONTAINER_WAV;</div>
|
|
<div class="line"><a name="l01550"></a><span class="lineno"> 1550</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01551"></a><span class="lineno"> 1551</span> </div>
|
|
<div class="line"><a name="l01552"></a><span class="lineno"> 1552</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'R'</span>,<span class="charliteral">'I'</span>,<span class="charliteral">'F'</span>,<span class="charliteral">'F'</span>):</div>
|
|
<div class="line"><a name="l01553"></a><span class="lineno"> 1553</span>  switch (Read32(buffer + 8)) {</div>
|
|
<div class="line"><a name="l01554"></a><span class="lineno"> 1554</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'A'</span>,<span class="charliteral">'V'</span>,<span class="charliteral">'I'</span>,<span class="charliteral">' '</span>):</div>
|
|
<div class="line"><a name="l01555"></a><span class="lineno"> 1555</span>  case TAG(<span class="stringliteral">'A'</span>,<span class="stringliteral">'V'</span>,<span class="stringliteral">'I'</span>,<span class="stringliteral">'X'</span>):</div>
|
|
<div class="line"><a name="l01556"></a><span class="lineno"> 1556</span>  case TAG(<span class="stringliteral">'A'</span>,<span class="stringliteral">'V'</span>,<span class="stringliteral">'I'</span>,<span class="stringliteral">'\x19'</span>):</div>
|
|
<div class="line"><a name="l01557"></a><span class="lineno"> 1557</span>  case TAG(<span class="stringliteral">'A'</span>,<span class="stringliteral">'M'</span>,<span class="stringliteral">'V'</span>,<span class="stringliteral">' '</span>):</div>
|
|
<div class="line"><a name="l01558"></a><span class="lineno"> 1558</span>  return CONTAINER_AVI;</div>
|
|
<div class="line"><a name="l01559"></a><span class="lineno"> 1559</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'W'</span>,<span class="charliteral">'A'</span>,<span class="charliteral">'V'</span>,<span class="charliteral">'E'</span>):</div>
|
|
<div class="line"><a name="l01560"></a><span class="lineno"> 1560</span>  return CONTAINER_WAV;</div>
|
|
<div class="line"><a name="l01561"></a><span class="lineno"> 1561</span>  }</div>
|
|
<div class="line"><a name="l01562"></a><span class="lineno"> 1562</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01563"></a><span class="lineno"> 1563</span> </div>
|
|
<div class="line"><a name="l01564"></a><span class="lineno"> 1564</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'['</span>,<span class="charliteral">'S'</span>,<span class="charliteral">'c'</span>,<span class="charliteral">'r'</span>):</div>
|
|
<div class="line"><a name="l01565"></a><span class="lineno"> 1565</span>  if (StartsWith(buffer, buffer_size, kAssSignature))</div>
|
|
<div class="line"><a name="l01566"></a><span class="lineno"> 1566</span>  return CONTAINER_ASS;</div>
|
|
<div class="line"><a name="l01567"></a><span class="lineno"> 1567</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01568"></a><span class="lineno"> 1568</span> </div>
|
|
<div class="line"><a name="l01569"></a><span class="lineno"> 1569</span>  <span class="keywordflow">case</span> TAG(<span class="stringliteral">'\xef'</span>,<span class="stringliteral">'\xbb'</span>,<span class="stringliteral">'\xbf'</span>,<span class="charliteral">'['</span>):</div>
|
|
<div class="line"><a name="l01570"></a><span class="lineno"> 1570</span>  if (StartsWith(buffer, buffer_size, kAssBomSignature))</div>
|
|
<div class="line"><a name="l01571"></a><span class="lineno"> 1571</span>  return CONTAINER_ASS;</div>
|
|
<div class="line"><a name="l01572"></a><span class="lineno"> 1572</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01573"></a><span class="lineno"> 1573</span> </div>
|
|
<div class="line"><a name="l01574"></a><span class="lineno"> 1574</span>  <span class="keywordflow">case</span> 0x7ffe8001:</div>
|
|
<div class="line"><a name="l01575"></a><span class="lineno"> 1575</span>  <span class="keywordflow">case</span> 0xfe7f0180:</div>
|
|
<div class="line"><a name="l01576"></a><span class="lineno"> 1576</span>  <span class="keywordflow">case</span> 0x1fffe800:</div>
|
|
<div class="line"><a name="l01577"></a><span class="lineno"> 1577</span>  <span class="keywordflow">case</span> 0xff1f00e8:</div>
|
|
<div class="line"><a name="l01578"></a><span class="lineno"> 1578</span>  <span class="keywordflow">if</span> (CheckDts(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01579"></a><span class="lineno"> 1579</span>  <span class="keywordflow">return</span> CONTAINER_DTS;</div>
|
|
<div class="line"><a name="l01580"></a><span class="lineno"> 1580</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01581"></a><span class="lineno"> 1581</span> </div>
|
|
<div class="line"><a name="l01582"></a><span class="lineno"> 1582</span>  <span class="keywordflow">case</span> 0xb7d80020:</div>
|
|
<div class="line"><a name="l01583"></a><span class="lineno"> 1583</span>  <span class="keywordflow">if</span> (StartsWith(buffer,</div>
|
|
<div class="line"><a name="l01584"></a><span class="lineno"> 1584</span>  buffer_size,</div>
|
|
<div class="line"><a name="l01585"></a><span class="lineno"> 1585</span>  kWtvSignature,</div>
|
|
<div class="line"><a name="l01586"></a><span class="lineno"> 1586</span>  <span class="keyword">sizeof</span>(kWtvSignature))) {</div>
|
|
<div class="line"><a name="l01587"></a><span class="lineno"> 1587</span>  <span class="keywordflow">return</span> CONTAINER_WTV;</div>
|
|
<div class="line"><a name="l01588"></a><span class="lineno"> 1588</span>  }</div>
|
|
<div class="line"><a name="l01589"></a><span class="lineno"> 1589</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01590"></a><span class="lineno"> 1590</span>  <span class="keywordflow">case</span> 0x000001ba:</div>
|
|
<div class="line"><a name="l01591"></a><span class="lineno"> 1591</span>  <span class="keywordflow">return</span> CONTAINER_MPEG2PS;</div>
|
|
<div class="line"><a name="l01592"></a><span class="lineno"> 1592</span>  }</div>
|
|
<div class="line"><a name="l01593"></a><span class="lineno"> 1593</span> </div>
|
|
<div class="line"><a name="l01594"></a><span class="lineno"> 1594</span>  <span class="comment">// Now try a few different ones that look at something other</span></div>
|
|
<div class="line"><a name="l01595"></a><span class="lineno"> 1595</span>  <span class="comment">// than the first 4 bytes.</span></div>
|
|
<div class="line"><a name="l01596"></a><span class="lineno"> 1596</span>  uint32_t first3 = first4 & 0xffffff00;</div>
|
|
<div class="line"><a name="l01597"></a><span class="lineno"> 1597</span>  <span class="keywordflow">switch</span> (first3) {</div>
|
|
<div class="line"><a name="l01598"></a><span class="lineno"> 1598</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'C'</span>,<span class="charliteral">'W'</span>,<span class="charliteral">'S'</span>,0):</div>
|
|
<div class="line"><a name="l01599"></a><span class="lineno"> 1599</span>  case TAG(<span class="stringliteral">'F'</span>,<span class="stringliteral">'W'</span>,<span class="stringliteral">'S'</span>,0):</div>
|
|
<div class="line"><a name="l01600"></a><span class="lineno"> 1600</span>  return CONTAINER_SWF;</div>
|
|
<div class="line"><a name="l01601"></a><span class="lineno"> 1601</span> </div>
|
|
<div class="line"><a name="l01602"></a><span class="lineno"> 1602</span>  <span class="keywordflow">case</span> TAG(<span class="charliteral">'I'</span>,<span class="charliteral">'D'</span>,<span class="charliteral">'3'</span>,0):</div>
|
|
<div class="line"><a name="l01603"></a><span class="lineno"> 1603</span>  if (CheckMp3(buffer, buffer_size, true))</div>
|
|
<div class="line"><a name="l01604"></a><span class="lineno"> 1604</span>  return CONTAINER_MP3;</div>
|
|
<div class="line"><a name="l01605"></a><span class="lineno"> 1605</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01606"></a><span class="lineno"> 1606</span>  }</div>
|
|
<div class="line"><a name="l01607"></a><span class="lineno"> 1607</span> </div>
|
|
<div class="line"><a name="l01608"></a><span class="lineno"> 1608</span>  <span class="comment">// Maybe the first 2 characters are something we can use.</span></div>
|
|
<div class="line"><a name="l01609"></a><span class="lineno"> 1609</span>  uint32_t first2 = Read16(buffer);</div>
|
|
<div class="line"><a name="l01610"></a><span class="lineno"> 1610</span>  <span class="keywordflow">switch</span> (first2) {</div>
|
|
<div class="line"><a name="l01611"></a><span class="lineno"> 1611</span>  <span class="keywordflow">case</span> kAc3SyncWord:</div>
|
|
<div class="line"><a name="l01612"></a><span class="lineno"> 1612</span>  <span class="keywordflow">if</span> (CheckAc3(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01613"></a><span class="lineno"> 1613</span>  <span class="keywordflow">return</span> CONTAINER_AC3;</div>
|
|
<div class="line"><a name="l01614"></a><span class="lineno"> 1614</span>  <span class="keywordflow">if</span> (CheckEac3(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01615"></a><span class="lineno"> 1615</span>  <span class="keywordflow">return</span> CONTAINER_EAC3;</div>
|
|
<div class="line"><a name="l01616"></a><span class="lineno"> 1616</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01617"></a><span class="lineno"> 1617</span> </div>
|
|
<div class="line"><a name="l01618"></a><span class="lineno"> 1618</span>  <span class="keywordflow">case</span> 0xfff0:</div>
|
|
<div class="line"><a name="l01619"></a><span class="lineno"> 1619</span>  <span class="keywordflow">case</span> 0xfff1:</div>
|
|
<div class="line"><a name="l01620"></a><span class="lineno"> 1620</span>  <span class="keywordflow">case</span> 0xfff8:</div>
|
|
<div class="line"><a name="l01621"></a><span class="lineno"> 1621</span>  <span class="keywordflow">case</span> 0xfff9:</div>
|
|
<div class="line"><a name="l01622"></a><span class="lineno"> 1622</span>  <span class="keywordflow">if</span> (CheckAac(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01623"></a><span class="lineno"> 1623</span>  <span class="keywordflow">return</span> CONTAINER_AAC;</div>
|
|
<div class="line"><a name="l01624"></a><span class="lineno"> 1624</span>  <span class="keywordflow">break</span>;</div>
|
|
<div class="line"><a name="l01625"></a><span class="lineno"> 1625</span>  }</div>
|
|
<div class="line"><a name="l01626"></a><span class="lineno"> 1626</span> </div>
|
|
<div class="line"><a name="l01627"></a><span class="lineno"> 1627</span>  <span class="comment">// Check if the file is in MP3 format without the header.</span></div>
|
|
<div class="line"><a name="l01628"></a><span class="lineno"> 1628</span>  <span class="keywordflow">if</span> (CheckMp3(buffer, buffer_size, <span class="keyword">false</span>))</div>
|
|
<div class="line"><a name="l01629"></a><span class="lineno"> 1629</span>  <span class="keywordflow">return</span> CONTAINER_MP3;</div>
|
|
<div class="line"><a name="l01630"></a><span class="lineno"> 1630</span> </div>
|
|
<div class="line"><a name="l01631"></a><span class="lineno"> 1631</span>  <span class="keywordflow">return</span> CONTAINER_UNKNOWN;</div>
|
|
<div class="line"><a name="l01632"></a><span class="lineno"> 1632</span> }</div>
|
|
<div class="line"><a name="l01633"></a><span class="lineno"> 1633</span> </div>
|
|
<div class="line"><a name="l01634"></a><span class="lineno"> 1634</span> <span class="keyword">namespace </span>{</div>
|
|
<div class="line"><a name="l01635"></a><span class="lineno"> 1635</span> <span class="keyword">const</span> <span class="keywordtype">char</span> kWebVtt[] = <span class="stringliteral">"WEBVTT"</span>;</div>
|
|
<div class="line"><a name="l01636"></a><span class="lineno"> 1636</span> </div>
|
|
<div class="line"><a name="l01637"></a><span class="lineno"> 1637</span> <span class="keywordtype">bool</span> CheckWebVtt(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l01638"></a><span class="lineno"> 1638</span>  <span class="keyword">const</span> <span class="keywordtype">int</span> offset =</div>
|
|
<div class="line"><a name="l01639"></a><span class="lineno"> 1639</span>  StartsWith(buffer, buffer_size, UTF8_BYTE_ORDER_MARK) ? 3 : 0;</div>
|
|
<div class="line"><a name="l01640"></a><span class="lineno"> 1640</span> </div>
|
|
<div class="line"><a name="l01641"></a><span class="lineno"> 1641</span>  <span class="keywordflow">return</span> StartsWith(buffer + offset, buffer_size - offset,</div>
|
|
<div class="line"><a name="l01642"></a><span class="lineno"> 1642</span>  reinterpret_cast<const uint8_t*>(kWebVtt),</div>
|
|
<div class="line"><a name="l01643"></a><span class="lineno"> 1643</span>  arraysize(kWebVtt) - 1);</div>
|
|
<div class="line"><a name="l01644"></a><span class="lineno"> 1644</span> }</div>
|
|
<div class="line"><a name="l01645"></a><span class="lineno"> 1645</span> </div>
|
|
<div class="line"><a name="l01646"></a><span class="lineno"> 1646</span> <span class="keywordtype">bool</span> CheckTtml(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l01647"></a><span class="lineno"> 1647</span>  <span class="comment">// Sanity check first before reading the entire thing.</span></div>
|
|
<div class="line"><a name="l01648"></a><span class="lineno"> 1648</span>  <span class="keywordflow">if</span> (!StartsWith(buffer, buffer_size, <span class="stringliteral">"<?xml"</span>))</div>
|
|
<div class="line"><a name="l01649"></a><span class="lineno"> 1649</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l01650"></a><span class="lineno"> 1650</span> </div>
|
|
<div class="line"><a name="l01651"></a><span class="lineno"> 1651</span>  <span class="comment">// Make sure that it can be parsed so that it doesn't error later in the</span></div>
|
|
<div class="line"><a name="l01652"></a><span class="lineno"> 1652</span>  <span class="comment">// process. Not doing a schema check to allow TTMLs that makes some sense but</span></div>
|
|
<div class="line"><a name="l01653"></a><span class="lineno"> 1653</span>  <span class="comment">// not necessarily compliant to the schema.</span></div>
|
|
<div class="line"><a name="l01654"></a><span class="lineno"> 1654</span>  xml::scoped_xml_ptr<xmlDoc> doc(</div>
|
|
<div class="line"><a name="l01655"></a><span class="lineno"> 1655</span>  xmlParseMemory(reinterpret_cast<const char*>(buffer), buffer_size));</div>
|
|
<div class="line"><a name="l01656"></a><span class="lineno"> 1656</span>  <span class="keywordflow">if</span> (!doc)</div>
|
|
<div class="line"><a name="l01657"></a><span class="lineno"> 1657</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l01658"></a><span class="lineno"> 1658</span> </div>
|
|
<div class="line"><a name="l01659"></a><span class="lineno"> 1659</span>  xmlNodePtr root_node = xmlDocGetRootElement(doc.get());</div>
|
|
<div class="line"><a name="l01660"></a><span class="lineno"> 1660</span>  std::string root_node_name(reinterpret_cast<const char*>(root_node->name));</div>
|
|
<div class="line"><a name="l01661"></a><span class="lineno"> 1661</span>  <span class="comment">// "tt" is supposed to be the top level element for ttml.</span></div>
|
|
<div class="line"><a name="l01662"></a><span class="lineno"> 1662</span>  <span class="keywordflow">return</span> root_node_name == <span class="stringliteral">"tt"</span>;</div>
|
|
<div class="line"><a name="l01663"></a><span class="lineno"> 1663</span> }</div>
|
|
<div class="line"><a name="l01664"></a><span class="lineno"> 1664</span> </div>
|
|
<div class="line"><a name="l01665"></a><span class="lineno"> 1665</span> } <span class="comment">// namespace</span></div>
|
|
<div class="line"><a name="l01666"></a><span class="lineno"> 1666</span> </div>
|
|
<div class="line"><a name="l01667"></a><span class="lineno"> 1667</span> <span class="comment">// Attempt to determine the container name from the buffer provided.</span></div>
|
|
<div class="line"><a name="l01668"></a><span class="lineno"> 1668</span> MediaContainerName DetermineContainer(<span class="keyword">const</span> uint8_t* buffer, <span class="keywordtype">int</span> buffer_size) {</div>
|
|
<div class="line"><a name="l01669"></a><span class="lineno"> 1669</span>  DCHECK(buffer);</div>
|
|
<div class="line"><a name="l01670"></a><span class="lineno"> 1670</span> </div>
|
|
<div class="line"><a name="l01671"></a><span class="lineno"> 1671</span>  <span class="comment">// Since MOV/QuickTime/MPEG4 streams are common, check for them first.</span></div>
|
|
<div class="line"><a name="l01672"></a><span class="lineno"> 1672</span>  <span class="keywordflow">if</span> (CheckMov(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01673"></a><span class="lineno"> 1673</span>  <span class="keywordflow">return</span> CONTAINER_MOV;</div>
|
|
<div class="line"><a name="l01674"></a><span class="lineno"> 1674</span> </div>
|
|
<div class="line"><a name="l01675"></a><span class="lineno"> 1675</span>  <span class="comment">// Next attempt the simple checks, that typically look at just the</span></div>
|
|
<div class="line"><a name="l01676"></a><span class="lineno"> 1676</span>  <span class="comment">// first few bytes of the file.</span></div>
|
|
<div class="line"><a name="l01677"></a><span class="lineno"> 1677</span>  MediaContainerName result = LookupContainerByFirst4(buffer, buffer_size);</div>
|
|
<div class="line"><a name="l01678"></a><span class="lineno"> 1678</span>  <span class="keywordflow">if</span> (result != CONTAINER_UNKNOWN)</div>
|
|
<div class="line"><a name="l01679"></a><span class="lineno"> 1679</span>  <span class="keywordflow">return</span> result;</div>
|
|
<div class="line"><a name="l01680"></a><span class="lineno"> 1680</span> </div>
|
|
<div class="line"><a name="l01681"></a><span class="lineno"> 1681</span>  <span class="comment">// WebVTT check only checks for the first few bytes.</span></div>
|
|
<div class="line"><a name="l01682"></a><span class="lineno"> 1682</span>  <span class="keywordflow">if</span> (CheckWebVtt(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01683"></a><span class="lineno"> 1683</span>  <span class="keywordflow">return</span> CONTAINER_WEBVTT;</div>
|
|
<div class="line"><a name="l01684"></a><span class="lineno"> 1684</span> </div>
|
|
<div class="line"><a name="l01685"></a><span class="lineno"> 1685</span>  <span class="comment">// Additional checks that may scan a portion of the buffer.</span></div>
|
|
<div class="line"><a name="l01686"></a><span class="lineno"> 1686</span>  <span class="keywordflow">if</span> (CheckMpeg2ProgramStream(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01687"></a><span class="lineno"> 1687</span>  <span class="keywordflow">return</span> CONTAINER_MPEG2PS;</div>
|
|
<div class="line"><a name="l01688"></a><span class="lineno"> 1688</span>  <span class="keywordflow">if</span> (CheckMpeg2TransportStream(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01689"></a><span class="lineno"> 1689</span>  <span class="keywordflow">return</span> CONTAINER_MPEG2TS;</div>
|
|
<div class="line"><a name="l01690"></a><span class="lineno"> 1690</span>  <span class="keywordflow">if</span> (CheckMJpeg(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01691"></a><span class="lineno"> 1691</span>  <span class="keywordflow">return</span> CONTAINER_MJPEG;</div>
|
|
<div class="line"><a name="l01692"></a><span class="lineno"> 1692</span>  <span class="keywordflow">if</span> (CheckDV(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01693"></a><span class="lineno"> 1693</span>  <span class="keywordflow">return</span> CONTAINER_DV;</div>
|
|
<div class="line"><a name="l01694"></a><span class="lineno"> 1694</span>  <span class="keywordflow">if</span> (CheckH261(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01695"></a><span class="lineno"> 1695</span>  <span class="keywordflow">return</span> CONTAINER_H261;</div>
|
|
<div class="line"><a name="l01696"></a><span class="lineno"> 1696</span>  <span class="keywordflow">if</span> (CheckH263(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01697"></a><span class="lineno"> 1697</span>  <span class="keywordflow">return</span> CONTAINER_H263;</div>
|
|
<div class="line"><a name="l01698"></a><span class="lineno"> 1698</span>  <span class="keywordflow">if</span> (CheckH264(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01699"></a><span class="lineno"> 1699</span>  <span class="keywordflow">return</span> CONTAINER_H264;</div>
|
|
<div class="line"><a name="l01700"></a><span class="lineno"> 1700</span>  <span class="keywordflow">if</span> (CheckMpeg4BitStream(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01701"></a><span class="lineno"> 1701</span>  <span class="keywordflow">return</span> CONTAINER_MPEG4BS;</div>
|
|
<div class="line"><a name="l01702"></a><span class="lineno"> 1702</span>  <span class="keywordflow">if</span> (CheckVC1(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01703"></a><span class="lineno"> 1703</span>  <span class="keywordflow">return</span> CONTAINER_VC1;</div>
|
|
<div class="line"><a name="l01704"></a><span class="lineno"> 1704</span>  <span class="keywordflow">if</span> (CheckSrt(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01705"></a><span class="lineno"> 1705</span>  <span class="keywordflow">return</span> CONTAINER_SRT;</div>
|
|
<div class="line"><a name="l01706"></a><span class="lineno"> 1706</span>  <span class="keywordflow">if</span> (CheckGsm(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01707"></a><span class="lineno"> 1707</span>  <span class="keywordflow">return</span> CONTAINER_GSM;</div>
|
|
<div class="line"><a name="l01708"></a><span class="lineno"> 1708</span> </div>
|
|
<div class="line"><a name="l01709"></a><span class="lineno"> 1709</span>  <span class="comment">// AC3/EAC3 might not start at the beginning of the stream,</span></div>
|
|
<div class="line"><a name="l01710"></a><span class="lineno"> 1710</span>  <span class="comment">// so scan for a start code.</span></div>
|
|
<div class="line"><a name="l01711"></a><span class="lineno"> 1711</span>  <span class="keywordtype">int</span> offset = 1; <span class="comment">// No need to start at byte 0 due to First4 check.</span></div>
|
|
<div class="line"><a name="l01712"></a><span class="lineno"> 1712</span>  <span class="keywordflow">if</span> (AdvanceToStartCode(buffer, buffer_size, &offset, 4, 16, kAc3SyncWord)) {</div>
|
|
<div class="line"><a name="l01713"></a><span class="lineno"> 1713</span>  <span class="keywordflow">if</span> (CheckAc3(buffer + offset, buffer_size - offset))</div>
|
|
<div class="line"><a name="l01714"></a><span class="lineno"> 1714</span>  <span class="keywordflow">return</span> CONTAINER_AC3;</div>
|
|
<div class="line"><a name="l01715"></a><span class="lineno"> 1715</span>  <span class="keywordflow">if</span> (CheckEac3(buffer + offset, buffer_size - offset))</div>
|
|
<div class="line"><a name="l01716"></a><span class="lineno"> 1716</span>  <span class="keywordflow">return</span> CONTAINER_EAC3;</div>
|
|
<div class="line"><a name="l01717"></a><span class="lineno"> 1717</span>  }</div>
|
|
<div class="line"><a name="l01718"></a><span class="lineno"> 1718</span> </div>
|
|
<div class="line"><a name="l01719"></a><span class="lineno"> 1719</span>  <span class="comment">// To do a TTML check, it parses the XML which requires scanning</span></div>
|
|
<div class="line"><a name="l01720"></a><span class="lineno"> 1720</span>  <span class="comment">// the whole content.</span></div>
|
|
<div class="line"><a name="l01721"></a><span class="lineno"> 1721</span>  <span class="keywordflow">if</span> (CheckTtml(buffer, buffer_size))</div>
|
|
<div class="line"><a name="l01722"></a><span class="lineno"> 1722</span>  <span class="keywordflow">return</span> CONTAINER_TTML;</div>
|
|
<div class="line"><a name="l01723"></a><span class="lineno"> 1723</span> </div>
|
|
<div class="line"><a name="l01724"></a><span class="lineno"> 1724</span>  <span class="keywordflow">return</span> CONTAINER_UNKNOWN;</div>
|
|
<div class="line"><a name="l01725"></a><span class="lineno"> 1725</span> }</div>
|
|
<div class="line"><a name="l01726"></a><span class="lineno"> 1726</span> </div>
|
|
<div class="line"><a name="l01727"></a><span class="lineno"> 1727</span> MediaContainerName DetermineContainerFromFormatName(</div>
|
|
<div class="line"><a name="l01728"></a><span class="lineno"> 1728</span>  <span class="keyword">const</span> std::string& format_name) {</div>
|
|
<div class="line"><a name="l01729"></a><span class="lineno"> 1729</span>  <span class="keywordflow">if</span> (base::EqualsCaseInsensitiveASCII(format_name, <span class="stringliteral">"webm"</span>)) {</div>
|
|
<div class="line"><a name="l01730"></a><span class="lineno"> 1730</span>  <span class="keywordflow">return</span> CONTAINER_WEBM;</div>
|
|
<div class="line"><a name="l01731"></a><span class="lineno"> 1731</span>  } <span class="keywordflow">else</span> <span class="keywordflow">if</span> (base::EqualsCaseInsensitiveASCII(format_name, <span class="stringliteral">"m4a"</span>) ||</div>
|
|
<div class="line"><a name="l01732"></a><span class="lineno"> 1732</span>  base::EqualsCaseInsensitiveASCII(format_name, <span class="stringliteral">"m4v"</span>) ||</div>
|
|
<div class="line"><a name="l01733"></a><span class="lineno"> 1733</span>  base::EqualsCaseInsensitiveASCII(format_name, <span class="stringliteral">"mp4"</span>) ||</div>
|
|
<div class="line"><a name="l01734"></a><span class="lineno"> 1734</span>  base::EqualsCaseInsensitiveASCII(format_name, <span class="stringliteral">"mov"</span>)) {</div>
|
|
<div class="line"><a name="l01735"></a><span class="lineno"> 1735</span>  <span class="keywordflow">return</span> CONTAINER_MOV;</div>
|
|
<div class="line"><a name="l01736"></a><span class="lineno"> 1736</span>  } <span class="keywordflow">else</span> <span class="keywordflow">if</span> (base::EqualsCaseInsensitiveASCII(format_name, <span class="stringliteral">"ts"</span>) ||</div>
|
|
<div class="line"><a name="l01737"></a><span class="lineno"> 1737</span>  base::EqualsCaseInsensitiveASCII(format_name, <span class="stringliteral">"mpeg2ts"</span>)) {</div>
|
|
<div class="line"><a name="l01738"></a><span class="lineno"> 1738</span>  <span class="keywordflow">return</span> CONTAINER_MPEG2TS;</div>
|
|
<div class="line"><a name="l01739"></a><span class="lineno"> 1739</span>  }</div>
|
|
<div class="line"><a name="l01740"></a><span class="lineno"> 1740</span>  <span class="keywordflow">return</span> CONTAINER_UNKNOWN;</div>
|
|
<div class="line"><a name="l01741"></a><span class="lineno"> 1741</span> }</div>
|
|
<div class="line"><a name="l01742"></a><span class="lineno"> 1742</span> </div>
|
|
<div class="line"><a name="l01743"></a><span class="lineno"> 1743</span> MediaContainerName DetermineContainerFromFileName(</div>
|
|
<div class="line"><a name="l01744"></a><span class="lineno"> 1744</span>  <span class="keyword">const</span> std::string& file_name) {</div>
|
|
<div class="line"><a name="l01745"></a><span class="lineno"> 1745</span>  <span class="keywordflow">if</span> (base::EndsWith(file_name, <span class="stringliteral">".webm"</span>,</div>
|
|
<div class="line"><a name="l01746"></a><span class="lineno"> 1746</span>  base::CompareCase::INSENSITIVE_ASCII)) {</div>
|
|
<div class="line"><a name="l01747"></a><span class="lineno"> 1747</span>  <span class="keywordflow">return</span> CONTAINER_WEBM;</div>
|
|
<div class="line"><a name="l01748"></a><span class="lineno"> 1748</span>  } <span class="keywordflow">else</span> <span class="keywordflow">if</span> (base::EndsWith(file_name, <span class="stringliteral">".mp4"</span>,</div>
|
|
<div class="line"><a name="l01749"></a><span class="lineno"> 1749</span>  base::CompareCase::INSENSITIVE_ASCII) ||</div>
|
|
<div class="line"><a name="l01750"></a><span class="lineno"> 1750</span>  base::EndsWith(file_name, <span class="stringliteral">".m4a"</span>,</div>
|
|
<div class="line"><a name="l01751"></a><span class="lineno"> 1751</span>  base::CompareCase::INSENSITIVE_ASCII) ||</div>
|
|
<div class="line"><a name="l01752"></a><span class="lineno"> 1752</span>  base::EndsWith(file_name, <span class="stringliteral">".m4v"</span>,</div>
|
|
<div class="line"><a name="l01753"></a><span class="lineno"> 1753</span>  base::CompareCase::INSENSITIVE_ASCII)) {</div>
|
|
<div class="line"><a name="l01754"></a><span class="lineno"> 1754</span>  <span class="keywordflow">return</span> CONTAINER_MOV;</div>
|
|
<div class="line"><a name="l01755"></a><span class="lineno"> 1755</span>  } <span class="keywordflow">else</span> <span class="keywordflow">if</span> (base::EndsWith(file_name, <span class="stringliteral">".ts"</span>,</div>
|
|
<div class="line"><a name="l01756"></a><span class="lineno"> 1756</span>  base::CompareCase::INSENSITIVE_ASCII)) {</div>
|
|
<div class="line"><a name="l01757"></a><span class="lineno"> 1757</span>  <span class="keywordflow">return</span> CONTAINER_MPEG2TS;</div>
|
|
<div class="line"><a name="l01758"></a><span class="lineno"> 1758</span>  } <span class="keywordflow">else</span> <span class="keywordflow">if</span> (base::EndsWith(file_name, <span class="stringliteral">".vtt"</span>,</div>
|
|
<div class="line"><a name="l01759"></a><span class="lineno"> 1759</span>  base::CompareCase::INSENSITIVE_ASCII)) {</div>
|
|
<div class="line"><a name="l01760"></a><span class="lineno"> 1760</span>  <span class="keywordflow">return</span> CONTAINER_WEBVTT;</div>
|
|
<div class="line"><a name="l01761"></a><span class="lineno"> 1761</span>  } <span class="keywordflow">else</span> <span class="keywordflow">if</span> (base::EndsWith(file_name, <span class="stringliteral">".webvtt"</span>,</div>
|
|
<div class="line"><a name="l01762"></a><span class="lineno"> 1762</span>  base::CompareCase::INSENSITIVE_ASCII)) {</div>
|
|
<div class="line"><a name="l01763"></a><span class="lineno"> 1763</span>  <span class="keywordflow">return</span> CONTAINER_WEBVTT;</div>
|
|
<div class="line"><a name="l01764"></a><span class="lineno"> 1764</span>  } <span class="keywordflow">else</span> <span class="keywordflow">if</span> (base::EndsWith(file_name, <span class="stringliteral">".ttml"</span>,</div>
|
|
<div class="line"><a name="l01765"></a><span class="lineno"> 1765</span>  base::CompareCase::INSENSITIVE_ASCII)) {</div>
|
|
<div class="line"><a name="l01766"></a><span class="lineno"> 1766</span>  <span class="keywordflow">return</span> CONTAINER_TTML;</div>
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<div class="line"><a name="l01767"></a><span class="lineno"> 1767</span>  } <span class="keywordflow">else</span> <span class="keywordflow">if</span> (base::EndsWith(file_name, <span class="stringliteral">".xml"</span>,</div>
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<div class="line"><a name="l01768"></a><span class="lineno"> 1768</span>  base::CompareCase::INSENSITIVE_ASCII)) {</div>
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<div class="line"><a name="l01769"></a><span class="lineno"> 1769</span>  <span class="comment">// In our supported containers, only ttml is in xml format.</span></div>
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<div class="line"><a name="l01770"></a><span class="lineno"> 1770</span>  <span class="keywordflow">return</span> CONTAINER_TTML;</div>
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<div class="line"><a name="l01771"></a><span class="lineno"> 1771</span>  }</div>
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<div class="line"><a name="l01772"></a><span class="lineno"> 1772</span>  <span class="keywordflow">return</span> CONTAINER_UNKNOWN;</div>
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<div class="line"><a name="l01773"></a><span class="lineno"> 1773</span> }</div>
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<div class="line"><a name="l01774"></a><span class="lineno"> 1774</span> </div>
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<div class="line"><a name="l01775"></a><span class="lineno"> 1775</span> } <span class="comment">// namespace media</span></div>
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<div class="line"><a name="l01776"></a><span class="lineno"> 1776</span> } <span class="comment">// namespace shaka</span></div>
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</a> 1.8.6
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