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<div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno"> 1</span>&#160;<span class="comment">// Copyright 2016 Google Inc. All rights reserved.</span></div>
<div class="line"><a name="l00002"></a><span class="lineno"> 2</span>&#160;<span class="comment">//</span></div>
<div class="line"><a name="l00003"></a><span class="lineno"> 3</span>&#160;<span class="comment">// Use of this source code is governed by a BSD-style</span></div>
<div class="line"><a name="l00004"></a><span class="lineno"> 4</span>&#160;<span class="comment">// license that can be found in the LICENSE file or at</span></div>
<div class="line"><a name="l00005"></a><span class="lineno"> 5</span>&#160;<span class="comment">// https://developers.google.com/open-source/licenses/bsd</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 &quot;packager/media/base/bit_reader.h&quot;</span></div>
<div class="line"><a name="l00008"></a><span class="lineno"> 8</span>&#160;<span class="preprocessor">#include &quot;packager/media/base/rcheck.h&quot;</span></div>
<div class="line"><a name="l00009"></a><span class="lineno"> 9</span>&#160;<span class="preprocessor">#include &quot;packager/media/codecs/ec3_audio_util.h&quot;</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="keyword">namespace </span>shaka {</div>
<div class="line"><a name="l00012"></a><span class="lineno"> 12</span>&#160;<span class="keyword">namespace </span>media {</div>
<div class="line"><a name="l00013"></a><span class="lineno"> 13</span>&#160;</div>
<div class="line"><a name="l00014"></a><span class="lineno"> 14</span>&#160;<span class="keyword">namespace </span>{</div>
<div class="line"><a name="l00015"></a><span class="lineno"> 15</span>&#160;</div>
<div class="line"><a name="l00016"></a><span class="lineno"> 16</span>&#160;<span class="comment">// Channels bit map. 16 bits.</span></div>
<div class="line"><a name="l00017"></a><span class="lineno"> 17</span>&#160;<span class="comment">// Bit, Location</span></div>
<div class="line"><a name="l00018"></a><span class="lineno"> 18</span>&#160;<span class="comment">// 0(MSB), Left</span></div>
<div class="line"><a name="l00019"></a><span class="lineno"> 19</span>&#160;<span class="comment">// 1, Center</span></div>
<div class="line"><a name="l00020"></a><span class="lineno"> 20</span>&#160;<span class="comment">// 2, Right</span></div>
<div class="line"><a name="l00021"></a><span class="lineno"> 21</span>&#160;<span class="comment">// 3, Left Surround</span></div>
<div class="line"><a name="l00022"></a><span class="lineno"> 22</span>&#160;<span class="comment">// 4, Right Surround</span></div>
<div class="line"><a name="l00023"></a><span class="lineno"> 23</span>&#160;<span class="comment">// 5, Left center/Right center pair</span></div>
<div class="line"><a name="l00024"></a><span class="lineno"> 24</span>&#160;<span class="comment">// 6, Left rear surround/Right rear surround pair</span></div>
<div class="line"><a name="l00025"></a><span class="lineno"> 25</span>&#160;<span class="comment">// 7, Center surround</span></div>
<div class="line"><a name="l00026"></a><span class="lineno"> 26</span>&#160;<span class="comment">// 8, Top center surround</span></div>
<div class="line"><a name="l00027"></a><span class="lineno"> 27</span>&#160;<span class="comment">// 9, Left surround direct/Right surround direct pair</span></div>
<div class="line"><a name="l00028"></a><span class="lineno"> 28</span>&#160;<span class="comment">// 10, Left wide/Right wide pair</span></div>
<div class="line"><a name="l00029"></a><span class="lineno"> 29</span>&#160;<span class="comment">// 11, Lvertical height/Right vertical height pair</span></div>
<div class="line"><a name="l00030"></a><span class="lineno"> 30</span>&#160;<span class="comment">// 12, Center vertical height</span></div>
<div class="line"><a name="l00031"></a><span class="lineno"> 31</span>&#160;<span class="comment">// 13, Lts/Rts pair</span></div>
<div class="line"><a name="l00032"></a><span class="lineno"> 32</span>&#160;<span class="comment">// 14, LFE2</span></div>
<div class="line"><a name="l00033"></a><span class="lineno"> 33</span>&#160;<span class="comment">// 15, LFE</span></div>
<div class="line"><a name="l00034"></a><span class="lineno"> 34</span>&#160;<span class="keyword">enum</span> kEC3AudioChannelMap {</div>
<div class="line"><a name="l00035"></a><span class="lineno"> 35</span>&#160; kLeft = 0x8000,</div>
<div class="line"><a name="l00036"></a><span class="lineno"> 36</span>&#160; kCenter = 0x4000,</div>
<div class="line"><a name="l00037"></a><span class="lineno"> 37</span>&#160; kRight = 0x2000,</div>
<div class="line"><a name="l00038"></a><span class="lineno"> 38</span>&#160; kLeftSurround = 0x1000,</div>
<div class="line"><a name="l00039"></a><span class="lineno"> 39</span>&#160; kRightSurround = 0x800,</div>
<div class="line"><a name="l00040"></a><span class="lineno"> 40</span>&#160; kLcRcPair = 0x400,</div>
<div class="line"><a name="l00041"></a><span class="lineno"> 41</span>&#160; kLrsRrsPair = 0x200,</div>
<div class="line"><a name="l00042"></a><span class="lineno"> 42</span>&#160; kCenterSurround = 0x100,</div>
<div class="line"><a name="l00043"></a><span class="lineno"> 43</span>&#160; kTopCenterSurround = 0x80,</div>
<div class="line"><a name="l00044"></a><span class="lineno"> 44</span>&#160; kLsdRsdPair = 0x40,</div>
<div class="line"><a name="l00045"></a><span class="lineno"> 45</span>&#160; kLwRwPair = 0x20,</div>
<div class="line"><a name="l00046"></a><span class="lineno"> 46</span>&#160; kLvhRvhPair = 0x10,</div>
<div class="line"><a name="l00047"></a><span class="lineno"> 47</span>&#160; kCenterVerticalHeight = 0x8,</div>
<div class="line"><a name="l00048"></a><span class="lineno"> 48</span>&#160; kLtsRtsPair = 0x4,</div>
<div class="line"><a name="l00049"></a><span class="lineno"> 49</span>&#160; kLFE2 = 0x2,</div>
<div class="line"><a name="l00050"></a><span class="lineno"> 50</span>&#160; kLFEScreen = 0x1</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;</div>
<div class="line"><a name="l00053"></a><span class="lineno"> 53</span>&#160;<span class="comment">// EC3 Audio coding mode map (acmod) to determine EC3 audio channel layout. The</span></div>
<div class="line"><a name="l00054"></a><span class="lineno"> 54</span>&#160;<span class="comment">// value stands for the existence of Left, Center, Right, Left surround, and</span></div>
<div class="line"><a name="l00055"></a><span class="lineno"> 55</span>&#160;<span class="comment">// Right surround.</span></div>
<div class="line"><a name="l00056"></a><span class="lineno"> 56</span>&#160;<span class="keyword">const</span> uint16_t kEC3AudioCodingModeMap[] = {</div>
<div class="line"><a name="l00057"></a><span class="lineno"> 57</span>&#160; kLeft | kRight,</div>
<div class="line"><a name="l00058"></a><span class="lineno"> 58</span>&#160; kCenter,</div>
<div class="line"><a name="l00059"></a><span class="lineno"> 59</span>&#160; kLeft | kRight,</div>
<div class="line"><a name="l00060"></a><span class="lineno"> 60</span>&#160; kLeft | kCenter | kRight,</div>
<div class="line"><a name="l00061"></a><span class="lineno"> 61</span>&#160; kLeft | kRight | kLeftSurround | kRightSurround,</div>
<div class="line"><a name="l00062"></a><span class="lineno"> 62</span>&#160; kLeft | kCenter | kRight | kLeftSurround | kRightSurround,</div>
<div class="line"><a name="l00063"></a><span class="lineno"> 63</span>&#160; kLeft | kRight | kLeftSurround | kRightSurround,</div>
<div class="line"><a name="l00064"></a><span class="lineno"> 64</span>&#160; kLeft | kCenter | kRight | kLeftSurround | kRightSurround,</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;</div>
<div class="line"><a name="l00067"></a><span class="lineno"> 67</span>&#160;<span class="comment">// Reverse bit order.</span></div>
<div class="line"><a name="l00068"></a><span class="lineno"> 68</span>&#160;uint8_t ReverseBits8(uint8_t n) {</div>
<div class="line"><a name="l00069"></a><span class="lineno"> 69</span>&#160; n = ((n &gt;&gt; 1) &amp; 0x55) | ((n &amp; 0x55) &lt;&lt; 1);</div>
<div class="line"><a name="l00070"></a><span class="lineno"> 70</span>&#160; n = ((n &gt;&gt; 2) &amp; 0x33) | ((n &amp; 0x33) &lt;&lt; 2);</div>
<div class="line"><a name="l00071"></a><span class="lineno"> 71</span>&#160; <span class="keywordflow">return</span> ((n &gt;&gt; 4) &amp; 0x0f) | ((n &amp; 0x0f) &lt;&lt; 4);</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;</div>
<div class="line"><a name="l00074"></a><span class="lineno"> 74</span>&#160;<span class="keywordtype">bool</span> ExtractEc3Data(<span class="keyword">const</span> std::vector&lt;uint8_t&gt;&amp; ec3_data,</div>
<div class="line"><a name="l00075"></a><span class="lineno"> 75</span>&#160; uint8_t* audio_coding_mode,</div>
<div class="line"><a name="l00076"></a><span class="lineno"> 76</span>&#160; <span class="keywordtype">bool</span>* lfe_channel_on,</div>
<div class="line"><a name="l00077"></a><span class="lineno"> 77</span>&#160; uint16_t* dependent_substreams_layout) {</div>
<div class="line"><a name="l00078"></a><span class="lineno"> 78</span>&#160; BitReader bit_reader(ec3_data.data(), ec3_data.size());</div>
<div class="line"><a name="l00079"></a><span class="lineno"> 79</span>&#160; <span class="comment">// Read number of independent substreams and parse the independent substreams.</span></div>
<div class="line"><a name="l00080"></a><span class="lineno"> 80</span>&#160; uint8_t number_independent_substreams;</div>
<div class="line"><a name="l00081"></a><span class="lineno"> 81</span>&#160; RCHECK(bit_reader.SkipBits(13) &amp;&amp;</div>
<div class="line"><a name="l00082"></a><span class="lineno"> 82</span>&#160; bit_reader.ReadBits(3, &amp;number_independent_substreams));</div>
<div class="line"><a name="l00083"></a><span class="lineno"> 83</span>&#160; <span class="comment">// The value of this field is one less than the number of independent</span></div>
<div class="line"><a name="l00084"></a><span class="lineno"> 84</span>&#160; <span class="comment">// substreams present.</span></div>
<div class="line"><a name="l00085"></a><span class="lineno"> 85</span>&#160; ++number_independent_substreams;</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">// Parse audio_coding_mode, dependent_substreams_layout and lfe_channel_on</span></div>
<div class="line"><a name="l00088"></a><span class="lineno"> 88</span>&#160; <span class="comment">// from the first independent substream.</span></div>
<div class="line"><a name="l00089"></a><span class="lineno"> 89</span>&#160; <span class="comment">// Independent substream in EC3Specific box:</span></div>
<div class="line"><a name="l00090"></a><span class="lineno"> 90</span>&#160; <span class="comment">// fscod: 2 bits</span></div>
<div class="line"><a name="l00091"></a><span class="lineno"> 91</span>&#160; <span class="comment">// bsid: 5 bits</span></div>
<div class="line"><a name="l00092"></a><span class="lineno"> 92</span>&#160; <span class="comment">// reserved_1: 1 bit</span></div>
<div class="line"><a name="l00093"></a><span class="lineno"> 93</span>&#160; <span class="comment">// asvc: 1 bit</span></div>
<div class="line"><a name="l00094"></a><span class="lineno"> 94</span>&#160; <span class="comment">// bsmod: 3 bits</span></div>
<div class="line"><a name="l00095"></a><span class="lineno"> 95</span>&#160; <span class="comment">// acmod: 3 bits</span></div>
<div class="line"><a name="l00096"></a><span class="lineno"> 96</span>&#160; <span class="comment">// lfeon: 1 bit</span></div>
<div class="line"><a name="l00097"></a><span class="lineno"> 97</span>&#160; <span class="comment">// reserved_2: 3 bits</span></div>
<div class="line"><a name="l00098"></a><span class="lineno"> 98</span>&#160; <span class="comment">// num_dep_sub: 4 bits</span></div>
<div class="line"><a name="l00099"></a><span class="lineno"> 99</span>&#160; <span class="comment">// If num_dep_sub &gt; 0, chan_loc is present and the size is 9 bits.</span></div>
<div class="line"><a name="l00100"></a><span class="lineno"> 100</span>&#160; <span class="comment">// Otherwise, reserved_3 is present and the size is 1 bit.</span></div>
<div class="line"><a name="l00101"></a><span class="lineno"> 101</span>&#160; <span class="comment">// chan_loc: 9 bits</span></div>
<div class="line"><a name="l00102"></a><span class="lineno"> 102</span>&#160; <span class="comment">// reserved_3: 1 bit</span></div>
<div class="line"><a name="l00103"></a><span class="lineno"> 103</span>&#160; RCHECK(bit_reader.SkipBits(12));</div>
<div class="line"><a name="l00104"></a><span class="lineno"> 104</span>&#160; RCHECK(bit_reader.ReadBits(3, audio_coding_mode));</div>
<div class="line"><a name="l00105"></a><span class="lineno"> 105</span>&#160; RCHECK(bit_reader.ReadBits(1, lfe_channel_on));</div>
<div class="line"><a name="l00106"></a><span class="lineno"> 106</span>&#160;</div>
<div class="line"><a name="l00107"></a><span class="lineno"> 107</span>&#160; uint8_t number_dependent_substreams = 0;</div>
<div class="line"><a name="l00108"></a><span class="lineno"> 108</span>&#160; RCHECK(bit_reader.SkipBits(3));</div>
<div class="line"><a name="l00109"></a><span class="lineno"> 109</span>&#160; RCHECK(bit_reader.ReadBits(4, &amp;number_dependent_substreams));</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; *dependent_substreams_layout = 0;</div>
<div class="line"><a name="l00112"></a><span class="lineno"> 112</span>&#160; <span class="keywordflow">if</span> (number_dependent_substreams &gt; 0) {</div>
<div class="line"><a name="l00113"></a><span class="lineno"> 113</span>&#160; RCHECK(bit_reader.ReadBits(9, dependent_substreams_layout));</div>
<div class="line"><a name="l00114"></a><span class="lineno"> 114</span>&#160; }</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; <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
<div class="line"><a name="l00117"></a><span class="lineno"> 117</span>&#160;}</div>
<div class="line"><a name="l00118"></a><span class="lineno"> 118</span>&#160;</div>
<div class="line"><a name="l00119"></a><span class="lineno"> 119</span>&#160;} <span class="comment">// namespace</span></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="keywordtype">bool</span> CalculateEC3ChannelMap(<span class="keyword">const</span> std::vector&lt;uint8_t&gt;&amp; ec3_data, uint32_t* channel_map) {</div>
<div class="line"><a name="l00122"></a><span class="lineno"> 122</span>&#160; uint8_t audio_coding_mode;</div>
<div class="line"><a name="l00123"></a><span class="lineno"> 123</span>&#160; <span class="keywordtype">bool</span> lfe_channel_on;</div>
<div class="line"><a name="l00124"></a><span class="lineno"> 124</span>&#160; uint16_t dependent_substreams_layout;</div>
<div class="line"><a name="l00125"></a><span class="lineno"> 125</span>&#160; <span class="keywordflow">if</span> (!ExtractEc3Data(ec3_data, &amp;audio_coding_mode, &amp;lfe_channel_on,</div>
<div class="line"><a name="l00126"></a><span class="lineno"> 126</span>&#160; &amp;dependent_substreams_layout))</div>
<div class="line"><a name="l00127"></a><span class="lineno"> 127</span>&#160; <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
<div class="line"><a name="l00128"></a><span class="lineno"> 128</span>&#160;</div>
<div class="line"><a name="l00129"></a><span class="lineno"> 129</span>&#160; <span class="comment">// Dependent substreams layout bit map:</span></div>
<div class="line"><a name="l00130"></a><span class="lineno"> 130</span>&#160; <span class="comment">// Bit, Location</span></div>
<div class="line"><a name="l00131"></a><span class="lineno"> 131</span>&#160; <span class="comment">// 0, Lc/Rc pair</span></div>
<div class="line"><a name="l00132"></a><span class="lineno"> 132</span>&#160; <span class="comment">// 1, Lrs/Rrs pair</span></div>
<div class="line"><a name="l00133"></a><span class="lineno"> 133</span>&#160; <span class="comment">// 2, Cs</span></div>
<div class="line"><a name="l00134"></a><span class="lineno"> 134</span>&#160; <span class="comment">// 3, Ts</span></div>
<div class="line"><a name="l00135"></a><span class="lineno"> 135</span>&#160; <span class="comment">// 4, Lsd/Rsd pair</span></div>
<div class="line"><a name="l00136"></a><span class="lineno"> 136</span>&#160; <span class="comment">// 5, Lw/Rw pair</span></div>
<div class="line"><a name="l00137"></a><span class="lineno"> 137</span>&#160; <span class="comment">// 6, Lvh/Rvh pair</span></div>
<div class="line"><a name="l00138"></a><span class="lineno"> 138</span>&#160; <span class="comment">// 7, Cvh</span></div>
<div class="line"><a name="l00139"></a><span class="lineno"> 139</span>&#160; <span class="comment">// 8(MSB), LFE2</span></div>
<div class="line"><a name="l00140"></a><span class="lineno"> 140</span>&#160; <span class="comment">// Reverse bit order of dependent substreams channel layout (LFE2 not</span></div>
<div class="line"><a name="l00141"></a><span class="lineno"> 141</span>&#160; <span class="comment">// included) to apply on channel_map bit 5 - 12.</span></div>
<div class="line"><a name="l00142"></a><span class="lineno"> 142</span>&#160; <span class="keyword">const</span> uint8_t reversed_dependent_substreams_layout =</div>
<div class="line"><a name="l00143"></a><span class="lineno"> 143</span>&#160; ReverseBits8(dependent_substreams_layout &amp; 0xFF);</div>
<div class="line"><a name="l00144"></a><span class="lineno"> 144</span>&#160;</div>
<div class="line"><a name="l00145"></a><span class="lineno"> 145</span>&#160; *channel_map = kEC3AudioCodingModeMap[audio_coding_mode] |</div>
<div class="line"><a name="l00146"></a><span class="lineno"> 146</span>&#160; (reversed_dependent_substreams_layout &lt;&lt; 3);</div>
<div class="line"><a name="l00147"></a><span class="lineno"> 147</span>&#160; <span class="keywordflow">if</span> (dependent_substreams_layout &amp; 0x100)</div>
<div class="line"><a name="l00148"></a><span class="lineno"> 148</span>&#160; *channel_map |= kLFE2;</div>
<div class="line"><a name="l00149"></a><span class="lineno"> 149</span>&#160; <span class="keywordflow">if</span> (lfe_channel_on)</div>
<div class="line"><a name="l00150"></a><span class="lineno"> 150</span>&#160; *channel_map |= kLFEScreen;</div>
<div class="line"><a name="l00151"></a><span class="lineno"> 151</span>&#160; <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
<div class="line"><a name="l00152"></a><span class="lineno"> 152</span>&#160;}</div>
<div class="line"><a name="l00153"></a><span class="lineno"> 153</span>&#160;</div>
<div class="line"><a name="l00154"></a><span class="lineno"> 154</span>&#160;} <span class="comment">// namespace media</span></div>
<div class="line"><a name="l00155"></a><span class="lineno"> 155</span>&#160;} <span class="comment">// namespace shaka</span></div>
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