184 lines
18 KiB
HTML
184 lines
18 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
|
<html xmlns="http://www.w3.org/1999/xhtml">
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
|
|
<meta http-equiv="X-UA-Compatible" content="IE=9"/>
|
|
<meta name="generator" content="Doxygen 1.8.17"/>
|
|
<meta name="viewport" content="width=device-width, initial-scale=1"/>
|
|
<title>Shaka Packager SDK: packager/media/codecs/h26x_bit_reader.h Source File</title>
|
|
<link href="../../tabs.css" rel="stylesheet" type="text/css"/>
|
|
<script type="text/javascript" src="../../jquery.js"></script>
|
|
<script type="text/javascript" src="../../dynsections.js"></script>
|
|
<link href="../../search/search.css" rel="stylesheet" type="text/css"/>
|
|
<script type="text/javascript" src="../../search/searchdata.js"></script>
|
|
<script type="text/javascript" src="../../search/search.js"></script>
|
|
<link href="../../doxygen.css" rel="stylesheet" type="text/css" />
|
|
</head>
|
|
<body>
|
|
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
|
|
<div id="titlearea">
|
|
<table cellspacing="0" cellpadding="0">
|
|
<tbody>
|
|
<tr style="height: 56px;">
|
|
<td id="projectalign" style="padding-left: 0.5em;">
|
|
<div id="projectname">Shaka Packager SDK
|
|
</div>
|
|
</td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
</div>
|
|
<!-- end header part -->
|
|
<!-- Generated by Doxygen 1.8.17 -->
|
|
<script type="text/javascript">
|
|
/* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&dn=gpl-2.0.txt GPL-v2 */
|
|
var searchBox = new SearchBox("searchBox", "../../search",false,'Search');
|
|
/* @license-end */
|
|
</script>
|
|
<script type="text/javascript" src="../../menudata.js"></script>
|
|
<script type="text/javascript" src="../../menu.js"></script>
|
|
<script type="text/javascript">
|
|
/* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&dn=gpl-2.0.txt GPL-v2 */
|
|
$(function() {
|
|
initMenu('../../',true,false,'search.php','Search');
|
|
$(document).ready(function() { init_search(); });
|
|
});
|
|
/* @license-end */</script>
|
|
<div id="main-nav"></div>
|
|
<!-- window showing the filter options -->
|
|
<div id="MSearchSelectWindow"
|
|
onmouseover="return searchBox.OnSearchSelectShow()"
|
|
onmouseout="return searchBox.OnSearchSelectHide()"
|
|
onkeydown="return searchBox.OnSearchSelectKey(event)">
|
|
</div>
|
|
|
|
<!-- iframe showing the search results (closed by default) -->
|
|
<div id="MSearchResultsWindow">
|
|
<iframe src="javascript:void(0)" frameborder="0"
|
|
name="MSearchResults" id="MSearchResults">
|
|
</iframe>
|
|
</div>
|
|
|
|
<div id="nav-path" class="navpath">
|
|
<ul>
|
|
<li class="navelem"><a class="el" href="../../dir_3f8eec2fc361645de4b1ec14c19fffc7.html">packager</a></li><li class="navelem"><a class="el" href="../../dir_f99dae54fe7170f791f339b952d5067a.html">media</a></li><li class="navelem"><a class="el" href="../../dir_64597db6ac7a9160e951a4226a03f10e.html">codecs</a></li> </ul>
|
|
</div>
|
|
</div><!-- top -->
|
|
<div class="header">
|
|
<div class="headertitle">
|
|
<div class="title">h26x_bit_reader.h</div> </div>
|
|
</div><!--header-->
|
|
<div class="contents">
|
|
<div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno"> 1</span> <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> <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> <span class="comment">// found in the LICENSE file.</span></div>
|
|
<div class="line"><a name="l00004"></a><span class="lineno"> 4</span> <span class="comment">//</span></div>
|
|
<div class="line"><a name="l00005"></a><span class="lineno"> 5</span> <span class="comment">// This file contains an implementation of an H264 Annex-B video stream parser.</span></div>
|
|
<div class="line"><a name="l00006"></a><span class="lineno"> 6</span>  </div>
|
|
<div class="line"><a name="l00007"></a><span class="lineno"> 7</span> <span class="preprocessor">#ifndef PACKAGER_MEDIA_CODECS_H264_BIT_READER_H_</span></div>
|
|
<div class="line"><a name="l00008"></a><span class="lineno"> 8</span> <span class="preprocessor">#define PACKAGER_MEDIA_CODECS_H264_BIT_READER_H_</span></div>
|
|
<div class="line"><a name="l00009"></a><span class="lineno"> 9</span>  </div>
|
|
<div class="line"><a name="l00010"></a><span class="lineno"> 10</span> <span class="preprocessor">#include <stdint.h></span></div>
|
|
<div class="line"><a name="l00011"></a><span class="lineno"> 11</span> <span class="preprocessor">#include <sys/types.h></span></div>
|
|
<div class="line"><a name="l00012"></a><span class="lineno"> 12</span>  </div>
|
|
<div class="line"><a name="l00013"></a><span class="lineno"> 13</span> <span class="preprocessor">#include "packager/base/macros.h"</span></div>
|
|
<div class="line"><a name="l00014"></a><span class="lineno"> 14</span>  </div>
|
|
<div class="line"><a name="l00015"></a><span class="lineno"> 15</span> <span class="keyword">namespace </span><a class="code" href="../../d8/daf/namespaceshaka.html">shaka</a> {</div>
|
|
<div class="line"><a name="l00016"></a><span class="lineno"> 16</span> <span class="keyword">namespace </span>media {</div>
|
|
<div class="line"><a name="l00017"></a><span class="lineno"> 17</span>  </div>
|
|
<div class="line"><a name="l00018"></a><span class="lineno"> 18</span> <span class="comment">// A class to provide bit-granularity reading of H.264/H.265 streams.</span></div>
|
|
<div class="line"><a name="l00019"></a><span class="lineno"> 19</span> <span class="comment">// This is not a generic bit reader class, as it takes into account</span></div>
|
|
<div class="line"><a name="l00020"></a><span class="lineno"> 20</span> <span class="comment">// H.264 stream-specific constraints, such as skipping emulation-prevention</span></div>
|
|
<div class="line"><a name="l00021"></a><span class="lineno"> 21</span> <span class="comment">// bytes and stop bits. See spec for more details.</span></div>
|
|
<div class="line"><a name="l00022"></a><span class="lineno"><a class="line" href="../../de/db4/classshaka_1_1media_1_1H26xBitReader.html"> 22</a></span> <span class="keyword">class </span><a class="code" href="../../de/db4/classshaka_1_1media_1_1H26xBitReader.html">H26xBitReader</a> {</div>
|
|
<div class="line"><a name="l00023"></a><span class="lineno"> 23</span>  <span class="keyword">public</span>:</div>
|
|
<div class="line"><a name="l00024"></a><span class="lineno"> 24</span>  <a class="code" href="../../de/db4/classshaka_1_1media_1_1H26xBitReader.html">H26xBitReader</a>();</div>
|
|
<div class="line"><a name="l00025"></a><span class="lineno"> 25</span>  ~<a class="code" href="../../de/db4/classshaka_1_1media_1_1H26xBitReader.html">H26xBitReader</a>();</div>
|
|
<div class="line"><a name="l00026"></a><span class="lineno"> 26</span>  </div>
|
|
<div class="line"><a name="l00027"></a><span class="lineno"> 27</span>  <span class="comment">// Initialize the reader to start reading at |data|, |size| being size</span></div>
|
|
<div class="line"><a name="l00028"></a><span class="lineno"> 28</span>  <span class="comment">// of |data| in bytes.</span></div>
|
|
<div class="line"><a name="l00029"></a><span class="lineno"> 29</span>  <span class="comment">// Return false on insufficient size of stream..</span></div>
|
|
<div class="line"><a name="l00030"></a><span class="lineno"> 30</span>  <span class="keywordtype">bool</span> Initialize(<span class="keyword">const</span> uint8_t* data, off_t size);</div>
|
|
<div class="line"><a name="l00031"></a><span class="lineno"> 31</span>  </div>
|
|
<div class="line"><a name="l00032"></a><span class="lineno"> 32</span>  <span class="comment">// Read |num_bits| next bits from stream and return in |*out|, first bit</span></div>
|
|
<div class="line"><a name="l00033"></a><span class="lineno"> 33</span>  <span class="comment">// from the stream starting at |num_bits| position in |*out|.</span></div>
|
|
<div class="line"><a name="l00034"></a><span class="lineno"> 34</span>  <span class="comment">// |num_bits| may be 1-32, inclusive.</span></div>
|
|
<div class="line"><a name="l00035"></a><span class="lineno"> 35</span>  <span class="comment">// Return false if the given number of bits cannot be read (not enough</span></div>
|
|
<div class="line"><a name="l00036"></a><span class="lineno"> 36</span>  <span class="comment">// bits in the stream), true otherwise.</span></div>
|
|
<div class="line"><a name="l00037"></a><span class="lineno"> 37</span>  <span class="keywordtype">bool</span> ReadBits(<span class="keywordtype">int</span> num_bits, <span class="keywordtype">int</span>* out);</div>
|
|
<div class="line"><a name="l00038"></a><span class="lineno"> 38</span>  </div>
|
|
<div class="line"><a name="l00039"></a><span class="lineno"> 39</span>  <span class="comment">// Read a single bit and return in |*out|.</span></div>
|
|
<div class="line"><a name="l00040"></a><span class="lineno"> 40</span>  <span class="comment">// Return false if the bit cannot be read (not enough bits in the stream),</span></div>
|
|
<div class="line"><a name="l00041"></a><span class="lineno"> 41</span>  <span class="comment">// true otherwise.</span></div>
|
|
<div class="line"><a name="l00042"></a><span class="lineno"> 42</span>  <span class="keywordtype">bool</span> ReadBool(<span class="keywordtype">bool</span>* out) {</div>
|
|
<div class="line"><a name="l00043"></a><span class="lineno"> 43</span>  <span class="keywordtype">int</span> value;</div>
|
|
<div class="line"><a name="l00044"></a><span class="lineno"> 44</span>  <span class="keywordflow">if</span> (!ReadBits(1, &value))</div>
|
|
<div class="line"><a name="l00045"></a><span class="lineno"> 45</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l00046"></a><span class="lineno"> 46</span>  *out = (value != 0);</div>
|
|
<div class="line"><a name="l00047"></a><span class="lineno"> 47</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00048"></a><span class="lineno"> 48</span>  }</div>
|
|
<div class="line"><a name="l00049"></a><span class="lineno"> 49</span>  </div>
|
|
<div class="line"><a name="l00050"></a><span class="lineno"> 50</span>  <span class="comment">// Skips the given number of bits (does not have to be less than 32 bits).</span></div>
|
|
<div class="line"><a name="l00051"></a><span class="lineno"> 51</span>  <span class="comment">// Return false if there aren't enough bits in the stream, true otherwise.</span></div>
|
|
<div class="line"><a name="l00052"></a><span class="lineno"> 52</span>  <span class="keywordtype">bool</span> SkipBits(<span class="keywordtype">int</span> num_bits);</div>
|
|
<div class="line"><a name="l00053"></a><span class="lineno"> 53</span>  </div>
|
|
<div class="line"><a name="l00054"></a><span class="lineno"> 54</span>  <span class="comment">// Exp-Golomb code parsing as specified in chapter 9.1 of the spec.</span></div>
|
|
<div class="line"><a name="l00055"></a><span class="lineno"> 55</span>  <span class="comment">// Read one unsigned exp-Golomb code from the stream and return in |*val|.</span></div>
|
|
<div class="line"><a name="l00056"></a><span class="lineno"> 56</span>  <span class="keywordtype">bool</span> ReadUE(<span class="keywordtype">int</span>* val);</div>
|
|
<div class="line"><a name="l00057"></a><span class="lineno"> 57</span>  </div>
|
|
<div class="line"><a name="l00058"></a><span class="lineno"> 58</span>  <span class="comment">// Read one signed exp-Golomb code from the stream and return in |*val|.</span></div>
|
|
<div class="line"><a name="l00059"></a><span class="lineno"> 59</span>  <span class="keywordtype">bool</span> ReadSE(<span class="keywordtype">int</span>* val);</div>
|
|
<div class="line"><a name="l00060"></a><span class="lineno"> 60</span>  </div>
|
|
<div class="line"><a name="l00061"></a><span class="lineno"> 61</span>  <span class="comment">// Return the number of bits left in the stream.</span></div>
|
|
<div class="line"><a name="l00062"></a><span class="lineno"> 62</span>  off_t NumBitsLeft();</div>
|
|
<div class="line"><a name="l00063"></a><span class="lineno"> 63</span>  </div>
|
|
<div class="line"><a name="l00064"></a><span class="lineno"> 64</span>  <span class="comment">// See the definition of more_rbsp_data() in spec.</span></div>
|
|
<div class="line"><a name="l00065"></a><span class="lineno"> 65</span>  <span class="keywordtype">bool</span> HasMoreRBSPData();</div>
|
|
<div class="line"><a name="l00066"></a><span class="lineno"> 66</span>  </div>
|
|
<div class="line"><a name="l00067"></a><span class="lineno"> 67</span>  <span class="comment">// Return the number of emulation prevention bytes already read.</span></div>
|
|
<div class="line"><a name="l00068"></a><span class="lineno"> 68</span>  <span class="keywordtype">size_t</span> NumEmulationPreventionBytesRead();</div>
|
|
<div class="line"><a name="l00069"></a><span class="lineno"> 69</span>  </div>
|
|
<div class="line"><a name="l00070"></a><span class="lineno"> 70</span>  <span class="keyword">private</span>:</div>
|
|
<div class="line"><a name="l00071"></a><span class="lineno"> 71</span>  <span class="comment">// Advance to the next byte, loading it into curr_byte_.</span></div>
|
|
<div class="line"><a name="l00072"></a><span class="lineno"> 72</span>  <span class="comment">// Return false on end of stream.</span></div>
|
|
<div class="line"><a name="l00073"></a><span class="lineno"> 73</span>  <span class="keywordtype">bool</span> UpdateCurrByte();</div>
|
|
<div class="line"><a name="l00074"></a><span class="lineno"> 74</span>  </div>
|
|
<div class="line"><a name="l00075"></a><span class="lineno"> 75</span>  <span class="comment">// Pointer to the next unread (not in curr_byte_) byte in the stream.</span></div>
|
|
<div class="line"><a name="l00076"></a><span class="lineno"> 76</span>  <span class="keyword">const</span> uint8_t* data_;</div>
|
|
<div class="line"><a name="l00077"></a><span class="lineno"> 77</span>  </div>
|
|
<div class="line"><a name="l00078"></a><span class="lineno"> 78</span>  <span class="comment">// Bytes left in the stream (without the curr_byte_).</span></div>
|
|
<div class="line"><a name="l00079"></a><span class="lineno"> 79</span>  off_t bytes_left_;</div>
|
|
<div class="line"><a name="l00080"></a><span class="lineno"> 80</span>  </div>
|
|
<div class="line"><a name="l00081"></a><span class="lineno"> 81</span>  <span class="comment">// Contents of the current byte; first unread bit starting at position</span></div>
|
|
<div class="line"><a name="l00082"></a><span class="lineno"> 82</span>  <span class="comment">// 8 - num_remaining_bits_in_curr_byte_ from MSB.</span></div>
|
|
<div class="line"><a name="l00083"></a><span class="lineno"> 83</span>  <span class="keywordtype">int</span> curr_byte_;</div>
|
|
<div class="line"><a name="l00084"></a><span class="lineno"> 84</span>  </div>
|
|
<div class="line"><a name="l00085"></a><span class="lineno"> 85</span>  <span class="comment">// Number of bits remaining in curr_byte_</span></div>
|
|
<div class="line"><a name="l00086"></a><span class="lineno"> 86</span>  <span class="keywordtype">int</span> num_remaining_bits_in_curr_byte_;</div>
|
|
<div class="line"><a name="l00087"></a><span class="lineno"> 87</span>  </div>
|
|
<div class="line"><a name="l00088"></a><span class="lineno"> 88</span>  <span class="comment">// Used in emulation prevention three byte detection (see spec).</span></div>
|
|
<div class="line"><a name="l00089"></a><span class="lineno"> 89</span>  <span class="comment">// Initially set to 0xffff to accept all initial two-byte sequences.</span></div>
|
|
<div class="line"><a name="l00090"></a><span class="lineno"> 90</span>  <span class="keywordtype">int</span> prev_two_bytes_;</div>
|
|
<div class="line"><a name="l00091"></a><span class="lineno"> 91</span>  </div>
|
|
<div class="line"><a name="l00092"></a><span class="lineno"> 92</span>  <span class="comment">// Number of emulation preventation bytes (0x000003) we met.</span></div>
|
|
<div class="line"><a name="l00093"></a><span class="lineno"> 93</span>  <span class="keywordtype">size_t</span> emulation_prevention_bytes_;</div>
|
|
<div class="line"><a name="l00094"></a><span class="lineno"> 94</span>  </div>
|
|
<div class="line"><a name="l00095"></a><span class="lineno"> 95</span>  DISALLOW_COPY_AND_ASSIGN(<a class="code" href="../../de/db4/classshaka_1_1media_1_1H26xBitReader.html">H26xBitReader</a>);</div>
|
|
<div class="line"><a name="l00096"></a><span class="lineno"> 96</span> };</div>
|
|
<div class="line"><a name="l00097"></a><span class="lineno"> 97</span>  </div>
|
|
<div class="line"><a name="l00098"></a><span class="lineno"> 98</span> } <span class="comment">// namespace media</span></div>
|
|
<div class="line"><a name="l00099"></a><span class="lineno"> 99</span> } <span class="comment">// namespace shaka</span></div>
|
|
<div class="line"><a name="l00100"></a><span class="lineno"> 100</span>  </div>
|
|
<div class="line"><a name="l00101"></a><span class="lineno"> 101</span> <span class="preprocessor">#endif // PACKAGER_MEDIA_CODECS_H264_BIT_READER_H_</span></div>
|
|
</div><!-- fragment --></div><!-- contents -->
|
|
<div class="ttc" id="anamespaceshaka_html"><div class="ttname"><a href="../../d8/daf/namespaceshaka.html">shaka</a></div><div class="ttdoc">All the methods that are virtual are virtual for mocking.</div><div class="ttdef"><b>Definition:</b> <a href="../../d4/d15/gflags__hex__bytes_8cc_source.html#l00011">gflags_hex_bytes.cc:11</a></div></div>
|
|
<div class="ttc" id="aclassshaka_1_1media_1_1H26xBitReader_html"><div class="ttname"><a href="../../de/db4/classshaka_1_1media_1_1H26xBitReader.html">shaka::media::H26xBitReader</a></div><div class="ttdef"><b>Definition:</b> <a href="../../d1/dc2/h26x__bit__reader_8h_source.html#l00022">h26x_bit_reader.h:22</a></div></div>
|
|
<!-- start footer part -->
|
|
<hr class="footer"/><address class="footer"><small>
|
|
Generated on Tue Jun 22 2021 00:16:04 for Shaka Packager SDK by  <a href="http://www.doxygen.org/index.html">
|
|
<img class="footer" src="../../doxygen.png" alt="doxygen"/>
|
|
</a> 1.8.17
|
|
</small></address>
|
|
</body>
|
|
</html>
|