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<div class="title">ts_section_pat.cc</div> </div>
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<div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno"> 1</span>&#160;<span class="comment">// Copyright 2014 The Chromium Authors. All rights reserved.</span></div>
<div class="line"><a name="l00002"></a><span class="lineno"> 2</span>&#160;<span class="comment">// Use of this source code is governed by a BSD-style license that can be</span></div>
<div class="line"><a name="l00003"></a><span class="lineno"> 3</span>&#160;<span class="comment">// found in the LICENSE file.</span></div>
<div class="line"><a name="l00004"></a><span class="lineno"> 4</span>&#160;</div>
<div class="line"><a name="l00005"></a><span class="lineno"> 5</span>&#160;<span class="preprocessor">#include &quot;packager/media/formats/mp2t/ts_section_pat.h&quot;</span></div>
<div class="line"><a name="l00006"></a><span class="lineno"> 6</span>&#160;</div>
<div class="line"><a name="l00007"></a><span class="lineno"> 7</span>&#160;<span class="preprocessor">#include &lt;vector&gt;</span></div>
<div class="line"><a name="l00008"></a><span class="lineno"> 8</span>&#160;</div>
<div class="line"><a name="l00009"></a><span class="lineno"> 9</span>&#160;<span class="preprocessor">#include &quot;packager/base/logging.h&quot;</span></div>
<div class="line"><a name="l00010"></a><span class="lineno"> 10</span>&#160;<span class="preprocessor">#include &quot;packager/media/base/bit_reader.h&quot;</span></div>
<div class="line"><a name="l00011"></a><span class="lineno"> 11</span>&#160;<span class="preprocessor">#include &quot;packager/media/formats/mp2t/mp2t_common.h&quot;</span></div>
<div class="line"><a name="l00012"></a><span class="lineno"> 12</span>&#160;</div>
<div class="line"><a name="l00013"></a><span class="lineno"> 13</span>&#160;<span class="keyword">namespace </span>shaka {</div>
<div class="line"><a name="l00014"></a><span class="lineno"> 14</span>&#160;<span class="keyword">namespace </span>media {</div>
<div class="line"><a name="l00015"></a><span class="lineno"> 15</span>&#160;<span class="keyword">namespace </span>mp2t {</div>
<div class="line"><a name="l00016"></a><span class="lineno"> 16</span>&#160;</div>
<div class="line"><a name="l00017"></a><span class="lineno"> 17</span>&#160;TsSectionPat::TsSectionPat(<span class="keyword">const</span> RegisterPmtCb&amp; register_pmt_cb)</div>
<div class="line"><a name="l00018"></a><span class="lineno"> 18</span>&#160; : register_pmt_cb_(register_pmt_cb),</div>
<div class="line"><a name="l00019"></a><span class="lineno"> 19</span>&#160; version_number_(-1) {</div>
<div class="line"><a name="l00020"></a><span class="lineno"> 20</span>&#160;}</div>
<div class="line"><a name="l00021"></a><span class="lineno"> 21</span>&#160;</div>
<div class="line"><a name="l00022"></a><span class="lineno"> 22</span>&#160;TsSectionPat::~TsSectionPat() {</div>
<div class="line"><a name="l00023"></a><span class="lineno"> 23</span>&#160;}</div>
<div class="line"><a name="l00024"></a><span class="lineno"> 24</span>&#160;</div>
<div class="line"><a name="l00025"></a><span class="lineno"> 25</span>&#160;<span class="keywordtype">bool</span> TsSectionPat::ParsePsiSection(BitReader* bit_reader) {</div>
<div class="line"><a name="l00026"></a><span class="lineno"> 26</span>&#160; <span class="comment">// Read the fixed section length.</span></div>
<div class="line"><a name="l00027"></a><span class="lineno"> 27</span>&#160; <span class="keywordtype">int</span> table_id;</div>
<div class="line"><a name="l00028"></a><span class="lineno"> 28</span>&#160; <span class="keywordtype">int</span> section_syntax_indicator;</div>
<div class="line"><a name="l00029"></a><span class="lineno"> 29</span>&#160; <span class="keywordtype">int</span> dummy_zero;</div>
<div class="line"><a name="l00030"></a><span class="lineno"> 30</span>&#160; <span class="keywordtype">int</span> reserved;</div>
<div class="line"><a name="l00031"></a><span class="lineno"> 31</span>&#160; <span class="keywordtype">int</span> section_length;</div>
<div class="line"><a name="l00032"></a><span class="lineno"> 32</span>&#160; <span class="keywordtype">int</span> transport_stream_id;</div>
<div class="line"><a name="l00033"></a><span class="lineno"> 33</span>&#160; <span class="keywordtype">int</span> version_number;</div>
<div class="line"><a name="l00034"></a><span class="lineno"> 34</span>&#160; <span class="keywordtype">int</span> current_next_indicator;</div>
<div class="line"><a name="l00035"></a><span class="lineno"> 35</span>&#160; <span class="keywordtype">int</span> section_number;</div>
<div class="line"><a name="l00036"></a><span class="lineno"> 36</span>&#160; <span class="keywordtype">int</span> last_section_number;</div>
<div class="line"><a name="l00037"></a><span class="lineno"> 37</span>&#160; RCHECK(bit_reader-&gt;ReadBits(8, &amp;table_id));</div>
<div class="line"><a name="l00038"></a><span class="lineno"> 38</span>&#160; RCHECK(bit_reader-&gt;ReadBits(1, &amp;section_syntax_indicator));</div>
<div class="line"><a name="l00039"></a><span class="lineno"> 39</span>&#160; RCHECK(bit_reader-&gt;ReadBits(1, &amp;dummy_zero));</div>
<div class="line"><a name="l00040"></a><span class="lineno"> 40</span>&#160; RCHECK(bit_reader-&gt;ReadBits(2, &amp;reserved));</div>
<div class="line"><a name="l00041"></a><span class="lineno"> 41</span>&#160; RCHECK(bit_reader-&gt;ReadBits(12, &amp;section_length));</div>
<div class="line"><a name="l00042"></a><span class="lineno"> 42</span>&#160; RCHECK(section_length &gt;= 5);</div>
<div class="line"><a name="l00043"></a><span class="lineno"> 43</span>&#160; RCHECK(section_length &lt;= 1021);</div>
<div class="line"><a name="l00044"></a><span class="lineno"> 44</span>&#160; RCHECK(bit_reader-&gt;ReadBits(16, &amp;transport_stream_id));</div>
<div class="line"><a name="l00045"></a><span class="lineno"> 45</span>&#160; RCHECK(bit_reader-&gt;ReadBits(2, &amp;reserved));</div>
<div class="line"><a name="l00046"></a><span class="lineno"> 46</span>&#160; RCHECK(bit_reader-&gt;ReadBits(5, &amp;version_number));</div>
<div class="line"><a name="l00047"></a><span class="lineno"> 47</span>&#160; RCHECK(bit_reader-&gt;ReadBits(1, &amp;current_next_indicator));</div>
<div class="line"><a name="l00048"></a><span class="lineno"> 48</span>&#160; RCHECK(bit_reader-&gt;ReadBits(8, &amp;section_number));</div>
<div class="line"><a name="l00049"></a><span class="lineno"> 49</span>&#160; RCHECK(bit_reader-&gt;ReadBits(8, &amp;last_section_number));</div>
<div class="line"><a name="l00050"></a><span class="lineno"> 50</span>&#160; section_length -= 5;</div>
<div class="line"><a name="l00051"></a><span class="lineno"> 51</span>&#160;</div>
<div class="line"><a name="l00052"></a><span class="lineno"> 52</span>&#160; <span class="comment">// Perform a few verifications:</span></div>
<div class="line"><a name="l00053"></a><span class="lineno"> 53</span>&#160; <span class="comment">// - Table ID should be 0 for a PAT.</span></div>
<div class="line"><a name="l00054"></a><span class="lineno"> 54</span>&#160; <span class="comment">// - section_syntax_indicator should be one.</span></div>
<div class="line"><a name="l00055"></a><span class="lineno"> 55</span>&#160; <span class="comment">// - section length should not exceed 1021</span></div>
<div class="line"><a name="l00056"></a><span class="lineno"> 56</span>&#160; RCHECK(table_id == 0x0);</div>
<div class="line"><a name="l00057"></a><span class="lineno"> 57</span>&#160; RCHECK(section_syntax_indicator);</div>
<div class="line"><a name="l00058"></a><span class="lineno"> 58</span>&#160; RCHECK(!dummy_zero);</div>
<div class="line"><a name="l00059"></a><span class="lineno"> 59</span>&#160;</div>
<div class="line"><a name="l00060"></a><span class="lineno"> 60</span>&#160; <span class="comment">// Both the program table and the CRC have a size multiple of 4.</span></div>
<div class="line"><a name="l00061"></a><span class="lineno"> 61</span>&#160; <span class="comment">// Note for pmt_pid_count: minus 4 to account for the CRC.</span></div>
<div class="line"><a name="l00062"></a><span class="lineno"> 62</span>&#160; RCHECK((section_length % 4) == 0);</div>
<div class="line"><a name="l00063"></a><span class="lineno"> 63</span>&#160; <span class="keywordtype">int</span> pmt_pid_count = (section_length - 4) / 4;</div>
<div class="line"><a name="l00064"></a><span class="lineno"> 64</span>&#160;</div>
<div class="line"><a name="l00065"></a><span class="lineno"> 65</span>&#160; <span class="comment">// Read the variable length section: program table &amp; crc.</span></div>
<div class="line"><a name="l00066"></a><span class="lineno"> 66</span>&#160; std::vector&lt;int&gt; program_number_array(pmt_pid_count);</div>
<div class="line"><a name="l00067"></a><span class="lineno"> 67</span>&#160; std::vector&lt;int&gt; pmt_pid_array(pmt_pid_count);</div>
<div class="line"><a name="l00068"></a><span class="lineno"> 68</span>&#160; <span class="keywordflow">for</span> (<span class="keywordtype">int</span> k = 0; k &lt; pmt_pid_count; k++) {</div>
<div class="line"><a name="l00069"></a><span class="lineno"> 69</span>&#160; <span class="keywordtype">int</span> reserved;</div>
<div class="line"><a name="l00070"></a><span class="lineno"> 70</span>&#160; RCHECK(bit_reader-&gt;ReadBits(16, &amp;program_number_array[k]));</div>
<div class="line"><a name="l00071"></a><span class="lineno"> 71</span>&#160; RCHECK(bit_reader-&gt;ReadBits(3, &amp;reserved));</div>
<div class="line"><a name="l00072"></a><span class="lineno"> 72</span>&#160; RCHECK(bit_reader-&gt;ReadBits(13, &amp;pmt_pid_array[k]));</div>
<div class="line"><a name="l00073"></a><span class="lineno"> 73</span>&#160; }</div>
<div class="line"><a name="l00074"></a><span class="lineno"> 74</span>&#160; <span class="keywordtype">int</span> crc32;</div>
<div class="line"><a name="l00075"></a><span class="lineno"> 75</span>&#160; RCHECK(bit_reader-&gt;ReadBits(32, &amp;crc32));</div>
<div class="line"><a name="l00076"></a><span class="lineno"> 76</span>&#160;</div>
<div class="line"><a name="l00077"></a><span class="lineno"> 77</span>&#160; <span class="comment">// Just ignore the PAT if not applicable yet.</span></div>
<div class="line"><a name="l00078"></a><span class="lineno"> 78</span>&#160; <span class="keywordflow">if</span> (!current_next_indicator) {</div>
<div class="line"><a name="l00079"></a><span class="lineno"> 79</span>&#160; DVLOG(1) &lt;&lt; <span class="stringliteral">&quot;Not supported: received a PAT not applicable yet&quot;</span>;</div>
<div class="line"><a name="l00080"></a><span class="lineno"> 80</span>&#160; <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
<div class="line"><a name="l00081"></a><span class="lineno"> 81</span>&#160; }</div>
<div class="line"><a name="l00082"></a><span class="lineno"> 82</span>&#160;</div>
<div class="line"><a name="l00083"></a><span class="lineno"> 83</span>&#160; <span class="comment">// Ignore the program table if it hasn&#39;t changed.</span></div>
<div class="line"><a name="l00084"></a><span class="lineno"> 84</span>&#160; <span class="keywordflow">if</span> (version_number == version_number_)</div>
<div class="line"><a name="l00085"></a><span class="lineno"> 85</span>&#160; <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
<div class="line"><a name="l00086"></a><span class="lineno"> 86</span>&#160;</div>
<div class="line"><a name="l00087"></a><span class="lineno"> 87</span>&#160; <span class="comment">// Both the MSE and the HLS spec specifies that TS streams should convey</span></div>
<div class="line"><a name="l00088"></a><span class="lineno"> 88</span>&#160; <span class="comment">// exactly one program.</span></div>
<div class="line"><a name="l00089"></a><span class="lineno"> 89</span>&#160; <span class="keywordflow">if</span> (pmt_pid_count &gt; 1) {</div>
<div class="line"><a name="l00090"></a><span class="lineno"> 90</span>&#160; DVLOG(1) &lt;&lt; <span class="stringliteral">&quot;Multiple programs detected in the Mpeg2 TS stream&quot;</span>;</div>
<div class="line"><a name="l00091"></a><span class="lineno"> 91</span>&#160; <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
<div class="line"><a name="l00092"></a><span class="lineno"> 92</span>&#160; }</div>
<div class="line"><a name="l00093"></a><span class="lineno"> 93</span>&#160;</div>
<div class="line"><a name="l00094"></a><span class="lineno"> 94</span>&#160; <span class="comment">// Can now register the PMT.</span></div>
<div class="line"><a name="l00095"></a><span class="lineno"> 95</span>&#160;<span class="preprocessor">#if !defined(NDEBUG)</span></div>
<div class="line"><a name="l00096"></a><span class="lineno"> 96</span>&#160;<span class="preprocessor"></span> <span class="keywordtype">int</span> expected_version_number = version_number;</div>
<div class="line"><a name="l00097"></a><span class="lineno"> 97</span>&#160; <span class="keywordflow">if</span> (version_number_ &gt;= 0)</div>
<div class="line"><a name="l00098"></a><span class="lineno"> 98</span>&#160; expected_version_number = (version_number_ + 1) % 32;</div>
<div class="line"><a name="l00099"></a><span class="lineno"> 99</span>&#160; DVLOG_IF(1, version_number != expected_version_number)</div>
<div class="line"><a name="l00100"></a><span class="lineno"> 100</span>&#160; &lt;&lt; <span class="stringliteral">&quot;Unexpected version number: &quot;</span></div>
<div class="line"><a name="l00101"></a><span class="lineno"> 101</span>&#160; &lt;&lt; version_number &lt;&lt; <span class="stringliteral">&quot; vs &quot;</span> &lt;&lt; version_number_;</div>
<div class="line"><a name="l00102"></a><span class="lineno"> 102</span>&#160;<span class="preprocessor">#endif</span></div>
<div class="line"><a name="l00103"></a><span class="lineno"> 103</span>&#160;<span class="preprocessor"></span> <span class="keywordflow">for</span> (<span class="keywordtype">int</span> k = 0; k &lt; pmt_pid_count; k++) {</div>
<div class="line"><a name="l00104"></a><span class="lineno"> 104</span>&#160; <span class="keywordflow">if</span> (program_number_array[k] != 0) {</div>
<div class="line"><a name="l00105"></a><span class="lineno"> 105</span>&#160; <span class="comment">// Program numbers different from 0 correspond to PMT.</span></div>
<div class="line"><a name="l00106"></a><span class="lineno"> 106</span>&#160; register_pmt_cb_.Run(program_number_array[k], pmt_pid_array[k]);</div>
<div class="line"><a name="l00107"></a><span class="lineno"> 107</span>&#160; <span class="comment">// Even if there are multiple programs, only one can be supported now.</span></div>
<div class="line"><a name="l00108"></a><span class="lineno"> 108</span>&#160; <span class="comment">// HLS: &quot;Transport Stream segments MUST contain a single MPEG-2 Program.&quot;</span></div>
<div class="line"><a name="l00109"></a><span class="lineno"> 109</span>&#160; <span class="keywordflow">break</span>;</div>
<div class="line"><a name="l00110"></a><span class="lineno"> 110</span>&#160; }</div>
<div class="line"><a name="l00111"></a><span class="lineno"> 111</span>&#160; }</div>
<div class="line"><a name="l00112"></a><span class="lineno"> 112</span>&#160; version_number_ = version_number;</div>
<div class="line"><a name="l00113"></a><span class="lineno"> 113</span>&#160;</div>
<div class="line"><a name="l00114"></a><span class="lineno"> 114</span>&#160; <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
<div class="line"><a name="l00115"></a><span class="lineno"> 115</span>&#160;}</div>
<div class="line"><a name="l00116"></a><span class="lineno"> 116</span>&#160;</div>
<div class="line"><a name="l00117"></a><span class="lineno"> 117</span>&#160;<span class="keywordtype">void</span> TsSectionPat::ResetPsiSection() {</div>
<div class="line"><a name="l00118"></a><span class="lineno"> 118</span>&#160; version_number_ = -1;</div>
<div class="line"><a name="l00119"></a><span class="lineno"> 119</span>&#160;}</div>
<div class="line"><a name="l00120"></a><span class="lineno"> 120</span>&#160;</div>
<div class="line"><a name="l00121"></a><span class="lineno"> 121</span>&#160;} <span class="comment">// namespace mp2t</span></div>
<div class="line"><a name="l00122"></a><span class="lineno"> 122</span>&#160;} <span class="comment">// namespace media</span></div>
<div class="line"><a name="l00123"></a><span class="lineno"> 123</span>&#160;} <span class="comment">// namespace shaka</span></div>
<div class="line"><a name="l00124"></a><span class="lineno"> 124</span>&#160;</div>
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