shaka-packager/docs/d4/dd3/bit__reader_8h_source.html

167 lines
16 KiB
HTML

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://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 1.8.6"/>
<title>DASH Media Packaging SDK: media/base/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/search.js"></script>
<script type="text/javascript">
$(document).ready(function() { searchBox.OnSelectItem(0); });
</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 style="padding-left: 0.5em;">
<div id="projectname">DASH Media Packaging SDK
</div>
</td>
</tr>
</tbody>
</table>
</div>
<!-- end header part -->
<!-- Generated by Doxygen 1.8.6 -->
<script type="text/javascript">
var searchBox = new SearchBox("searchBox", "../../search",false,'Search');
</script>
<div id="navrow1" class="tabs">
<ul class="tablist">
<li><a href="../../index.html"><span>Main&#160;Page</span></a></li>
<li><a href="../../namespaces.html"><span>Namespaces</span></a></li>
<li><a href="../../annotated.html"><span>Classes</span></a></li>
<li class="current"><a href="../../files.html"><span>Files</span></a></li>
<li>
<div id="MSearchBox" class="MSearchBoxInactive">
<span class="left">
<img id="MSearchSelect" src="../../search/mag_sel.png"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
alt=""/>
<input type="text" id="MSearchField" value="Search" accesskey="S"
onfocus="searchBox.OnSearchFieldFocus(true)"
onblur="searchBox.OnSearchFieldFocus(false)"
onkeyup="searchBox.OnSearchFieldChange(event)"/>
</span><span class="right">
<a id="MSearchClose" href="javascript:searchBox.CloseResultsWindow()"><img id="MSearchCloseImg" border="0" src="../../search/close.png" alt=""/></a>
</span>
</div>
</li>
</ul>
</div>
<div id="navrow2" class="tabs2">
<ul class="tablist">
<li><a href="../../files.html"><span>File&#160;List</span></a></li>
</ul>
</div>
<!-- window showing the filter options -->
<div id="MSearchSelectWindow"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
onkeydown="return searchBox.OnSearchSelectKey(event)">
<a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(0)"><span class="SelectionMark">&#160;</span>All</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(1)"><span class="SelectionMark">&#160;</span>Classes</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(2)"><span class="SelectionMark">&#160;</span>Namespaces</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(3)"><span class="SelectionMark">&#160;</span>Functions</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(4)"><span class="SelectionMark">&#160;</span>Variables</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(5)"><span class="SelectionMark">&#160;</span>Typedefs</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(6)"><span class="SelectionMark">&#160;</span>Enumerator</a></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_39dc0668bd5a501998f94e8b4e546c71.html">media</a></li><li class="navelem"><a class="el" href="../../dir_c6ada2450b25ab5438a4dba6c9b890af.html">base</a></li> </ul>
</div>
</div><!-- top -->
<div class="header">
<div class="headertitle">
<div class="title">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>&#160;<span class="comment">// Copyright (c) 2012 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">#ifndef MEDIA_BASE_BIT_READER_H_</span></div>
<div class="line"><a name="l00006"></a><span class="lineno"> 6</span>&#160;<span class="preprocessor"></span><span class="preprocessor">#define MEDIA_BASE_BIT_READER_H_</span></div>
<div class="line"><a name="l00007"></a><span class="lineno"> 7</span>&#160;<span class="preprocessor"></span></div>
<div class="line"><a name="l00008"></a><span class="lineno"> 8</span>&#160;<span class="preprocessor">#include &lt;stdint.h&gt;</span></div>
<div class="line"><a name="l00009"></a><span class="lineno"> 9</span>&#160;<span class="preprocessor">#include &lt;sys/types.h&gt;</span></div>
<div class="line"><a name="l00010"></a><span class="lineno"> 10</span>&#160;</div>
<div class="line"><a name="l00011"></a><span class="lineno"> 11</span>&#160;<span class="preprocessor">#include &quot;packager/base/logging.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>edash_packager {</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;</div>
<div class="line"><a name="l00017"></a><span class="lineno"><a class="line" href="../../df/db4/classedash__packager_1_1media_1_1BitReader.html"> 17</a></span>&#160;<span class="keyword">class </span><a class="code" href="../../df/db4/classedash__packager_1_1media_1_1BitReader.html">BitReader</a> {</div>
<div class="line"><a name="l00018"></a><span class="lineno"> 18</span>&#160; <span class="keyword">public</span>:</div>
<div class="line"><a name="l00022"></a><span class="lineno"> 22</span>&#160; <a class="code" href="../../df/db4/classedash__packager_1_1media_1_1BitReader.html#a7cfecfaf6169a0c9286d62b24e7b934e">BitReader</a>(<span class="keyword">const</span> uint8_t* data, off_t size);</div>
<div class="line"><a name="l00023"></a><span class="lineno"> 23</span>&#160; ~<a class="code" href="../../df/db4/classedash__packager_1_1media_1_1BitReader.html">BitReader</a>();</div>
<div class="line"><a name="l00024"></a><span class="lineno"> 24</span>&#160;</div>
<div class="line"><a name="l00034"></a><span class="lineno"> 34</span>&#160; <span class="keyword">template</span> &lt;<span class="keyword">typename</span> T&gt;</div>
<div class="line"><a name="l00035"></a><span class="lineno"><a class="line" href="../../df/db4/classedash__packager_1_1media_1_1BitReader.html#a9a66cdd1013eb535e7e1eec60a91bf8c"> 35</a></span>&#160; <span class="keywordtype">bool</span> <a class="code" href="../../df/db4/classedash__packager_1_1media_1_1BitReader.html#a9a66cdd1013eb535e7e1eec60a91bf8c">ReadBits</a>(<span class="keywordtype">int</span> num_bits, T* out) {</div>
<div class="line"><a name="l00036"></a><span class="lineno"> 36</span>&#160; DCHECK_LE(num_bits, static_cast&lt;int&gt;(<span class="keyword">sizeof</span>(T) * 8));</div>
<div class="line"><a name="l00037"></a><span class="lineno"> 37</span>&#160; uint64_t temp;</div>
<div class="line"><a name="l00038"></a><span class="lineno"> 38</span>&#160; <span class="keywordtype">bool</span> ret = ReadBitsInternal(num_bits, &amp;temp);</div>
<div class="line"><a name="l00039"></a><span class="lineno"> 39</span>&#160; *out = <span class="keyword">static_cast&lt;</span>T<span class="keyword">&gt;</span>(temp);</div>
<div class="line"><a name="l00040"></a><span class="lineno"> 40</span>&#160; <span class="keywordflow">return</span> ret;</div>
<div class="line"><a name="l00041"></a><span class="lineno"> 41</span>&#160; }</div>
<div class="line"><a name="l00042"></a><span class="lineno"> 42</span>&#160;</div>
<div class="line"><a name="l00049"></a><span class="lineno"> 49</span>&#160; <span class="keywordtype">bool</span> <a class="code" href="../../df/db4/classedash__packager_1_1media_1_1BitReader.html#acacb97d71aaae01796b90d27e7cdca0a">SkipBits</a>(<span class="keywordtype">int</span> num_bits);</div>
<div class="line"><a name="l00050"></a><span class="lineno"> 50</span>&#160;</div>
<div class="line"><a name="l00052"></a><span class="lineno"> 52</span>&#160; <span class="keywordtype">int</span> <a class="code" href="../../df/db4/classedash__packager_1_1media_1_1BitReader.html#a1409a0968749ca5a55ba823cd718065b">bits_available</a>() <span class="keyword">const</span>;</div>
<div class="line"><a name="l00053"></a><span class="lineno"> 53</span>&#160;</div>
<div class="line"><a name="l00054"></a><span class="lineno"> 54</span>&#160; <span class="keyword">private</span>:</div>
<div class="line"><a name="l00055"></a><span class="lineno"> 55</span>&#160; <span class="comment">// Help function used by ReadBits to avoid inlining the bit reading logic.</span></div>
<div class="line"><a name="l00056"></a><span class="lineno"> 56</span>&#160; <span class="keywordtype">bool</span> ReadBitsInternal(<span class="keywordtype">int</span> num_bits, uint64_t* out);</div>
<div class="line"><a name="l00057"></a><span class="lineno"> 57</span>&#160;</div>
<div class="line"><a name="l00058"></a><span class="lineno"> 58</span>&#160; <span class="comment">// Advance to the next byte, loading it into curr_byte_.</span></div>
<div class="line"><a name="l00059"></a><span class="lineno"> 59</span>&#160; <span class="comment">// If the num_remaining_bits_in_curr_byte_ is 0 after this function returns,</span></div>
<div class="line"><a name="l00060"></a><span class="lineno"> 60</span>&#160; <span class="comment">// the stream has reached the end.</span></div>
<div class="line"><a name="l00061"></a><span class="lineno"> 61</span>&#160; <span class="keywordtype">void</span> UpdateCurrByte();</div>
<div class="line"><a name="l00062"></a><span class="lineno"> 62</span>&#160;</div>
<div class="line"><a name="l00063"></a><span class="lineno"> 63</span>&#160; <span class="comment">// Pointer to the next unread (not in curr_byte_) byte in the stream.</span></div>
<div class="line"><a name="l00064"></a><span class="lineno"> 64</span>&#160; <span class="keyword">const</span> uint8_t* data_;</div>
<div class="line"><a name="l00065"></a><span class="lineno"> 65</span>&#160;</div>
<div class="line"><a name="l00066"></a><span class="lineno"> 66</span>&#160; <span class="comment">// Bytes left in the stream (without the curr_byte_).</span></div>
<div class="line"><a name="l00067"></a><span class="lineno"> 67</span>&#160; off_t bytes_left_;</div>
<div class="line"><a name="l00068"></a><span class="lineno"> 68</span>&#160;</div>
<div class="line"><a name="l00069"></a><span class="lineno"> 69</span>&#160; <span class="comment">// Contents of the current byte; first unread bit starting at position</span></div>
<div class="line"><a name="l00070"></a><span class="lineno"> 70</span>&#160; <span class="comment">// 8 - num_remaining_bits_in_curr_byte_ from MSB.</span></div>
<div class="line"><a name="l00071"></a><span class="lineno"> 71</span>&#160; uint8_t curr_byte_;</div>
<div class="line"><a name="l00072"></a><span class="lineno"> 72</span>&#160;</div>
<div class="line"><a name="l00073"></a><span class="lineno"> 73</span>&#160; <span class="comment">// Number of bits remaining in curr_byte_</span></div>
<div class="line"><a name="l00074"></a><span class="lineno"> 74</span>&#160; <span class="keywordtype">int</span> num_remaining_bits_in_curr_byte_;</div>
<div class="line"><a name="l00075"></a><span class="lineno"> 75</span>&#160;</div>
<div class="line"><a name="l00076"></a><span class="lineno"> 76</span>&#160; <span class="keyword">private</span>:</div>
<div class="line"><a name="l00077"></a><span class="lineno"> 77</span>&#160; DISALLOW_COPY_AND_ASSIGN(<a class="code" href="../../df/db4/classedash__packager_1_1media_1_1BitReader.html">BitReader</a>);</div>
<div class="line"><a name="l00078"></a><span class="lineno"> 78</span>&#160;};</div>
<div class="line"><a name="l00079"></a><span class="lineno"> 79</span>&#160;</div>
<div class="line"><a name="l00080"></a><span class="lineno"> 80</span>&#160;} <span class="comment">// namespace media</span></div>
<div class="line"><a name="l00081"></a><span class="lineno"> 81</span>&#160;} <span class="comment">// namespace edash_packager</span></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="preprocessor">#endif // MEDIA_BASE_BIT_READER_H_</span></div>
<div class="ttc" id="classedash__packager_1_1media_1_1BitReader_html_a7cfecfaf6169a0c9286d62b24e7b934e"><div class="ttname"><a href="../../df/db4/classedash__packager_1_1media_1_1BitReader.html#a7cfecfaf6169a0c9286d62b24e7b934e">edash_packager::media::BitReader::BitReader</a></div><div class="ttdeci">BitReader(const uint8_t *data, off_t size)</div><div class="ttdef"><b>Definition:</b> <a href="../../d5/de0/bit__reader_8cc_source.html#l00012">bit_reader.cc:12</a></div></div>
<div class="ttc" id="classedash__packager_1_1media_1_1BitReader_html_a9a66cdd1013eb535e7e1eec60a91bf8c"><div class="ttname"><a href="../../df/db4/classedash__packager_1_1media_1_1BitReader.html#a9a66cdd1013eb535e7e1eec60a91bf8c">edash_packager::media::BitReader::ReadBits</a></div><div class="ttdeci">bool ReadBits(int num_bits, T *out)</div><div class="ttdef"><b>Definition:</b> <a href="../../d4/dd3/bit__reader_8h_source.html#l00035">bit_reader.h:35</a></div></div>
<div class="ttc" id="classedash__packager_1_1media_1_1BitReader_html_a1409a0968749ca5a55ba823cd718065b"><div class="ttname"><a href="../../df/db4/classedash__packager_1_1media_1_1BitReader.html#a1409a0968749ca5a55ba823cd718065b">edash_packager::media::BitReader::bits_available</a></div><div class="ttdeci">int bits_available() const </div><div class="ttdef"><b>Definition:</b> <a href="../../d5/de0/bit__reader_8cc_source.html#l00053">bit_reader.cc:53</a></div></div>
<div class="ttc" id="classedash__packager_1_1media_1_1BitReader_html"><div class="ttname"><a href="../../df/db4/classedash__packager_1_1media_1_1BitReader.html">edash_packager::media::BitReader</a></div><div class="ttdoc">A class to read bit streams. </div><div class="ttdef"><b>Definition:</b> <a href="../../d4/dd3/bit__reader_8h_source.html#l00017">bit_reader.h:17</a></div></div>
<div class="ttc" id="classedash__packager_1_1media_1_1BitReader_html_acacb97d71aaae01796b90d27e7cdca0a"><div class="ttname"><a href="../../df/db4/classedash__packager_1_1media_1_1BitReader.html#acacb97d71aaae01796b90d27e7cdca0a">edash_packager::media::BitReader::SkipBits</a></div><div class="ttdeci">bool SkipBits(int num_bits)</div><div class="ttdef"><b>Definition:</b> <a href="../../d5/de0/bit__reader_8cc_source.html#l00021">bit_reader.cc:21</a></div></div>
</div><!-- fragment --></div><!-- contents -->
<!-- start footer part -->
<hr class="footer"/><address class="footer"><small>
Generated on Fri Nov 13 2015 19:02:30 for DASH Media Packaging SDK by &#160;<a href="http://www.doxygen.org/index.html">
<img class="footer" src="../../doxygen.png" alt="doxygen"/>
</a> 1.8.6
</small></address>
</body>
</html>