1 | <?php |
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2 | ///////////////////////////////////////////////////////////////// |
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3 | /// getID3() by James Heinrich <info@getid3.org> // |
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4 | // available at http://getid3.sourceforge.net // |
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5 | // or http://www.getid3.org // |
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6 | ///////////////////////////////////////////////////////////////// |
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7 | // See readme.txt for more details // |
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8 | ///////////////////////////////////////////////////////////////// |
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9 | // // |
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10 | // module.audio-video.mpeg.php // |
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11 | // module for analyzing MPEG files // |
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12 | // dependencies: module.audio.mp3.php // |
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13 | // /// |
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14 | ///////////////////////////////////////////////////////////////// |
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15 | |
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16 | getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio.mp3.php', __FILE__, true); |
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17 | |
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18 | define('GETID3_MPEG_VIDEO_PICTURE_START', "\x00\x00\x01\x00"); |
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19 | define('GETID3_MPEG_VIDEO_USER_DATA_START', "\x00\x00\x01\xB2"); |
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20 | define('GETID3_MPEG_VIDEO_SEQUENCE_HEADER', "\x00\x00\x01\xB3"); |
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21 | define('GETID3_MPEG_VIDEO_SEQUENCE_ERROR', "\x00\x00\x01\xB4"); |
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22 | define('GETID3_MPEG_VIDEO_EXTENSION_START', "\x00\x00\x01\xB5"); |
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23 | define('GETID3_MPEG_VIDEO_SEQUENCE_END', "\x00\x00\x01\xB7"); |
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24 | define('GETID3_MPEG_VIDEO_GROUP_START', "\x00\x00\x01\xB8"); |
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25 | define('GETID3_MPEG_AUDIO_START', "\x00\x00\x01\xC0"); |
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26 | |
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27 | |
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28 | class getid3_mpeg |
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29 | { |
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30 | |
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31 | function getid3_mpeg(&$fd, &$ThisFileInfo) { |
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32 | if ($ThisFileInfo['avdataend'] <= $ThisFileInfo['avdataoffset']) { |
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33 | $ThisFileInfo['error'][] = '"avdataend" ('.$ThisFileInfo['avdataend'].') is unexpectedly less-than-or-equal-to "avdataoffset" ('.$ThisFileInfo['avdataoffset'].')'; |
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34 | return false; |
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35 | } |
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36 | $ThisFileInfo['fileformat'] = 'mpeg'; |
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37 | fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET); |
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38 | $MPEGstreamData = fread($fd, min(100000, $ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset'])); |
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39 | $MPEGstreamDataLength = strlen($MPEGstreamData); |
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40 | |
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41 | $foundVideo = true; |
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42 | $VideoChunkOffset = 0; |
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43 | while (substr($MPEGstreamData, $VideoChunkOffset++, 4) !== GETID3_MPEG_VIDEO_SEQUENCE_HEADER) { |
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44 | if ($VideoChunkOffset >= $MPEGstreamDataLength) { |
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45 | $foundVideo = false; |
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46 | break; |
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47 | } |
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48 | } |
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49 | if ($foundVideo) { |
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50 | |
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51 | // Start code 32 bits |
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52 | // horizontal frame size 12 bits |
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53 | // vertical frame size 12 bits |
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54 | // pixel aspect ratio 4 bits |
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55 | // frame rate 4 bits |
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56 | // bitrate 18 bits |
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57 | // marker bit 1 bit |
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58 | // VBV buffer size 10 bits |
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59 | // constrained parameter flag 1 bit |
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60 | // intra quant. matrix flag 1 bit |
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61 | // intra quant. matrix values 512 bits (present if matrix flag == 1) |
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62 | // non-intra quant. matrix flag 1 bit |
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63 | // non-intra quant. matrix values 512 bits (present if matrix flag == 1) |
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64 | |
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65 | $ThisFileInfo['video']['dataformat'] = 'mpeg'; |
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66 | |
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67 | $VideoChunkOffset += (strlen(GETID3_MPEG_VIDEO_SEQUENCE_HEADER) - 1); |
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68 | |
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69 | $FrameSizeDWORD = getid3_lib::BigEndian2Int(substr($MPEGstreamData, $VideoChunkOffset, 3)); |
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70 | $VideoChunkOffset += 3; |
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71 | |
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72 | $AspectRatioFrameRateDWORD = getid3_lib::BigEndian2Int(substr($MPEGstreamData, $VideoChunkOffset, 1)); |
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73 | $VideoChunkOffset += 1; |
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74 | |
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75 | $assortedinformation = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $VideoChunkOffset, 4)); |
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76 | $VideoChunkOffset += 4; |
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77 | |
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78 | $ThisFileInfo['mpeg']['video']['raw']['framesize_horizontal'] = ($FrameSizeDWORD & 0xFFF000) >> 12; // 12 bits for horizontal frame size |
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79 | $ThisFileInfo['mpeg']['video']['raw']['framesize_vertical'] = ($FrameSizeDWORD & 0x000FFF); // 12 bits for vertical frame size |
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80 | $ThisFileInfo['mpeg']['video']['raw']['pixel_aspect_ratio'] = ($AspectRatioFrameRateDWORD & 0xF0) >> 4; |
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81 | $ThisFileInfo['mpeg']['video']['raw']['frame_rate'] = ($AspectRatioFrameRateDWORD & 0x0F); |
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82 | |
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83 | $ThisFileInfo['mpeg']['video']['framesize_horizontal'] = $ThisFileInfo['mpeg']['video']['raw']['framesize_horizontal']; |
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84 | $ThisFileInfo['mpeg']['video']['framesize_vertical'] = $ThisFileInfo['mpeg']['video']['raw']['framesize_vertical']; |
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85 | |
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86 | $ThisFileInfo['mpeg']['video']['pixel_aspect_ratio'] = $this->MPEGvideoAspectRatioLookup($ThisFileInfo['mpeg']['video']['raw']['pixel_aspect_ratio']); |
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87 | $ThisFileInfo['mpeg']['video']['pixel_aspect_ratio_text'] = $this->MPEGvideoAspectRatioTextLookup($ThisFileInfo['mpeg']['video']['raw']['pixel_aspect_ratio']); |
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88 | $ThisFileInfo['mpeg']['video']['frame_rate'] = $this->MPEGvideoFramerateLookup($ThisFileInfo['mpeg']['video']['raw']['frame_rate']); |
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89 | |
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90 | $ThisFileInfo['mpeg']['video']['raw']['bitrate'] = getid3_lib::Bin2Dec(substr($assortedinformation, 0, 18)); |
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91 | $ThisFileInfo['mpeg']['video']['raw']['marker_bit'] = (bool) getid3_lib::Bin2Dec(substr($assortedinformation, 18, 1)); |
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92 | $ThisFileInfo['mpeg']['video']['raw']['vbv_buffer_size'] = getid3_lib::Bin2Dec(substr($assortedinformation, 19, 10)); |
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93 | $ThisFileInfo['mpeg']['video']['raw']['constrained_param_flag'] = (bool) getid3_lib::Bin2Dec(substr($assortedinformation, 29, 1)); |
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94 | $ThisFileInfo['mpeg']['video']['raw']['intra_quant_flag'] = (bool) getid3_lib::Bin2Dec(substr($assortedinformation, 30, 1)); |
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95 | if ($ThisFileInfo['mpeg']['video']['raw']['intra_quant_flag']) { |
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96 | |
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97 | // read 512 bits |
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98 | $ThisFileInfo['mpeg']['video']['raw']['intra_quant'] = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $VideoChunkOffset, 64)); |
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99 | $VideoChunkOffset += 64; |
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100 | |
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101 | $ThisFileInfo['mpeg']['video']['raw']['non_intra_quant_flag'] = (bool) getid3_lib::Bin2Dec(substr($ThisFileInfo['mpeg']['video']['raw']['intra_quant'], 511, 1)); |
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102 | $ThisFileInfo['mpeg']['video']['raw']['intra_quant'] = getid3_lib::Bin2Dec(substr($assortedinformation, 31, 1)).substr(getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $VideoChunkOffset, 64)), 0, 511); |
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103 | |
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104 | if ($ThisFileInfo['mpeg']['video']['raw']['non_intra_quant_flag']) { |
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105 | $ThisFileInfo['mpeg']['video']['raw']['non_intra_quant'] = substr($MPEGstreamData, $VideoChunkOffset, 64); |
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106 | $VideoChunkOffset += 64; |
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107 | } |
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108 | |
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109 | } else { |
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110 | |
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111 | $ThisFileInfo['mpeg']['video']['raw']['non_intra_quant_flag'] = (bool) getid3_lib::Bin2Dec(substr($assortedinformation, 31, 1)); |
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112 | if ($ThisFileInfo['mpeg']['video']['raw']['non_intra_quant_flag']) { |
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113 | $ThisFileInfo['mpeg']['video']['raw']['non_intra_quant'] = substr($MPEGstreamData, $VideoChunkOffset, 64); |
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114 | $VideoChunkOffset += 64; |
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115 | } |
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116 | |
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117 | } |
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118 | |
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119 | if ($ThisFileInfo['mpeg']['video']['raw']['bitrate'] == 0x3FFFF) { // 18 set bits |
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120 | |
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121 | $ThisFileInfo['warning'][] = 'This version of getID3() ['.GETID3_VERSION.'] cannot determine average bitrate of VBR MPEG video files'; |
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122 | $ThisFileInfo['mpeg']['video']['bitrate_mode'] = 'vbr'; |
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123 | |
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124 | } else { |
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125 | |
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126 | $ThisFileInfo['mpeg']['video']['bitrate'] = $ThisFileInfo['mpeg']['video']['raw']['bitrate'] * 400; |
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127 | $ThisFileInfo['mpeg']['video']['bitrate_mode'] = 'cbr'; |
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128 | $ThisFileInfo['video']['bitrate'] = $ThisFileInfo['mpeg']['video']['bitrate']; |
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129 | |
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130 | } |
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131 | |
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132 | $ThisFileInfo['video']['resolution_x'] = $ThisFileInfo['mpeg']['video']['framesize_horizontal']; |
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133 | $ThisFileInfo['video']['resolution_y'] = $ThisFileInfo['mpeg']['video']['framesize_vertical']; |
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134 | $ThisFileInfo['video']['frame_rate'] = $ThisFileInfo['mpeg']['video']['frame_rate']; |
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135 | $ThisFileInfo['video']['bitrate_mode'] = $ThisFileInfo['mpeg']['video']['bitrate_mode']; |
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136 | $ThisFileInfo['video']['pixel_aspect_ratio'] = $ThisFileInfo['mpeg']['video']['pixel_aspect_ratio']; |
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137 | $ThisFileInfo['video']['lossless'] = false; |
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138 | $ThisFileInfo['video']['bits_per_sample'] = 24; |
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139 | |
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140 | } else { |
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141 | |
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142 | $ThisFileInfo['error'][] = 'Could not find start of video block in the first 100,000 bytes (or before end of file) - this might not be an MPEG-video file?'; |
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143 | |
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144 | } |
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145 | |
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146 | //0x000001B3 begins the sequence_header of every MPEG video stream. |
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147 | //But in MPEG-2, this header must immediately be followed by an |
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148 | //extension_start_code (0x000001B5) with a sequence_extension ID (1). |
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149 | //(This extension contains all the additional MPEG-2 stuff.) |
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150 | //MPEG-1 doesn't have this extension, so that's a sure way to tell the |
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151 | //difference between MPEG-1 and MPEG-2 video streams. |
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152 | |
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153 | if (substr($MPEGstreamData, $VideoChunkOffset, 4) == GETID3_MPEG_VIDEO_EXTENSION_START) { |
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154 | $ThisFileInfo['video']['codec'] = 'MPEG-2'; |
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155 | } else { |
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156 | $ThisFileInfo['video']['codec'] = 'MPEG-1'; |
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157 | } |
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158 | |
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159 | |
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160 | $AudioChunkOffset = 0; |
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161 | while (true) { |
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162 | while (substr($MPEGstreamData, $AudioChunkOffset++, 4) !== GETID3_MPEG_AUDIO_START) { |
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163 | if ($AudioChunkOffset >= $MPEGstreamDataLength) { |
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164 | break 2; |
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165 | } |
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166 | } |
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167 | |
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168 | for ($i = 0; $i <= 7; $i++) { |
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169 | // some files have the MPEG-audio header 8 bytes after the end of the $00 $00 $01 $C0 signature, some have it up to 13 bytes (or more?) after |
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170 | // I have no idea why or what the difference is, so this is a stupid hack. |
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171 | // If anybody has any better idea of what's going on, please let me know - info@getid3.org |
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172 | |
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173 | $dummy = $ThisFileInfo; |
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174 | if (getid3_mp3::decodeMPEGaudioHeader($fd, ($AudioChunkOffset + 3) + 8 + $i, $dummy, false)) { |
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175 | $ThisFileInfo = $dummy; |
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176 | $ThisFileInfo['audio']['bitrate_mode'] = 'cbr'; |
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177 | $ThisFileInfo['audio']['lossless'] = false; |
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178 | break 2; |
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179 | |
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180 | } |
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181 | } |
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182 | } |
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183 | |
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184 | // Temporary hack to account for interleaving overhead: |
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185 | if (!empty($ThisFileInfo['video']['bitrate']) && !empty($ThisFileInfo['audio']['bitrate'])) { |
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186 | $ThisFileInfo['playtime_seconds'] = (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8) / ($ThisFileInfo['video']['bitrate'] + $ThisFileInfo['audio']['bitrate']); |
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187 | |
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188 | // Interleaved MPEG audio/video files have a certain amount of overhead that varies |
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189 | // by both video and audio bitrates, and not in any sensible, linear/logarithmic patter |
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190 | // Use interpolated lookup tables to approximately guess how much is overhead, because |
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191 | // playtime is calculated as filesize / total-bitrate |
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192 | $ThisFileInfo['playtime_seconds'] *= $this->MPEGsystemNonOverheadPercentage($ThisFileInfo['video']['bitrate'], $ThisFileInfo['audio']['bitrate']); |
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193 | |
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194 | //switch ($ThisFileInfo['video']['bitrate']) { |
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195 | // case('5000000'): |
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196 | // $multiplier = 0.93292642112380355828048824319889; |
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197 | // break; |
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198 | // case('5500000'): |
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199 | // $multiplier = 0.93582895375200989965359777343219; |
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200 | // break; |
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201 | // case('6000000'): |
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202 | // $multiplier = 0.93796247714820932532911373859139; |
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203 | // break; |
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204 | // case('7000000'): |
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205 | // $multiplier = 0.9413264083635103463010117778776; |
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206 | // break; |
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207 | // default: |
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208 | // $multiplier = 1; |
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209 | // break; |
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210 | //} |
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211 | //$ThisFileInfo['playtime_seconds'] *= $multiplier; |
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212 | //$ThisFileInfo['warning'][] = 'Interleaved MPEG audio/video playtime may be inaccurate. With current hack should be within a few seconds of accurate. Report to info@getid3.org if off by more than 10 seconds.'; |
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213 | if ($ThisFileInfo['video']['bitrate'] < 50000) { |
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214 | $ThisFileInfo['warning'][] = 'Interleaved MPEG audio/video playtime may be slightly inaccurate for video bitrates below 100kbps. Except in extreme low-bitrate situations, error should be less than 1%. Report to info@getid3.org if greater than this.'; |
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215 | } |
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216 | } |
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217 | |
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218 | return true; |
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219 | } |
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220 | |
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221 | |
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222 | function MPEGsystemNonOverheadPercentage($VideoBitrate, $AudioBitrate) { |
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223 | $OverheadPercentage = 0; |
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224 | |
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225 | $AudioBitrate = max(min($AudioBitrate / 1000, 384), 32); // limit to range of 32kbps - 384kbps (should be only legal bitrates, but maybe VBR?) |
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226 | $VideoBitrate = max(min($VideoBitrate / 1000, 10000), 10); // limit to range of 10kbps - 10Mbps (beyond that curves flatten anyways, no big loss) |
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227 | |
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228 | |
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229 | //OMBB[audiobitrate] = array(video-10kbps, video-100kbps, video-1000kbps, video-10000kbps) |
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230 | $OverheadMultiplierByBitrate[32] = array(0, 0.9676287944368530, 0.9802276264360310, 0.9844916183244460, 0.9852821845179940); |
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231 | $OverheadMultiplierByBitrate[48] = array(0, 0.9779100089209830, 0.9787770035359320, 0.9846738664076130, 0.9852683013799960); |
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232 | $OverheadMultiplierByBitrate[56] = array(0, 0.9731249855367600, 0.9776624308938040, 0.9832606361852130, 0.9843922606633340); |
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233 | $OverheadMultiplierByBitrate[64] = array(0, 0.9755642683275760, 0.9795256705493390, 0.9836573009193170, 0.9851122539404470); |
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234 | $OverheadMultiplierByBitrate[96] = array(0, 0.9788025247497290, 0.9798553314148700, 0.9822956869792560, 0.9834815119124690); |
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235 | $OverheadMultiplierByBitrate[128] = array(0, 0.9816940050925480, 0.9821675936072120, 0.9829756927470870, 0.9839763420152050); |
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236 | $OverheadMultiplierByBitrate[160] = array(0, 0.9825894094561180, 0.9820913399073960, 0.9823907143253970, 0.9832821783651570); |
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237 | $OverheadMultiplierByBitrate[192] = array(0, 0.9832038474336260, 0.9825731694317960, 0.9821028622712400, 0.9828262076447620); |
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238 | $OverheadMultiplierByBitrate[224] = array(0, 0.9836516298538770, 0.9824718601823890, 0.9818302180625380, 0.9823735101626480); |
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239 | $OverheadMultiplierByBitrate[256] = array(0, 0.9845863022094920, 0.9837229411967540, 0.9824521662210830, 0.9828645172100790); |
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240 | $OverheadMultiplierByBitrate[320] = array(0, 0.9849565280263180, 0.9837683142805110, 0.9822885275960400, 0.9824424382727190); |
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241 | $OverheadMultiplierByBitrate[384] = array(0, 0.9856094774357600, 0.9844573394432720, 0.9825970399837330, 0.9824673808303890); |
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242 | |
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243 | $BitrateToUseMin = 32; |
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244 | $BitrateToUseMax = 32; |
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245 | $previousBitrate = 32; |
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246 | foreach ($OverheadMultiplierByBitrate as $key => $value) { |
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247 | if ($AudioBitrate >= $previousBitrate) { |
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248 | $BitrateToUseMin = $previousBitrate; |
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249 | } |
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250 | if ($AudioBitrate < $key) { |
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251 | $BitrateToUseMax = $key; |
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252 | break; |
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253 | } |
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254 | $previousBitrate = $key; |
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255 | } |
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256 | $FactorA = ($BitrateToUseMax - $AudioBitrate) / ($BitrateToUseMax - $BitrateToUseMin); |
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257 | |
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258 | $VideoBitrateLog10 = log10($VideoBitrate); |
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259 | $VideoFactorMin1 = $OverheadMultiplierByBitrate[$BitrateToUseMin][floor($VideoBitrateLog10)]; |
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260 | $VideoFactorMin2 = $OverheadMultiplierByBitrate[$BitrateToUseMax][floor($VideoBitrateLog10)]; |
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261 | $VideoFactorMax1 = $OverheadMultiplierByBitrate[$BitrateToUseMin][ceil($VideoBitrateLog10)]; |
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262 | $VideoFactorMax2 = $OverheadMultiplierByBitrate[$BitrateToUseMax][ceil($VideoBitrateLog10)]; |
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263 | $FactorV = $VideoBitrateLog10 - floor($VideoBitrateLog10); |
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264 | |
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265 | $OverheadPercentage = $VideoFactorMin1 * $FactorA * $FactorV; |
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266 | $OverheadPercentage += $VideoFactorMin2 * (1 - $FactorA) * $FactorV; |
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267 | $OverheadPercentage += $VideoFactorMax1 * $FactorA * (1 - $FactorV); |
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268 | $OverheadPercentage += $VideoFactorMax2 * (1 - $FactorA) * (1 - $FactorV); |
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269 | |
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270 | return $OverheadPercentage; |
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271 | } |
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272 | |
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273 | |
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274 | function MPEGvideoFramerateLookup($rawframerate) { |
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275 | $MPEGvideoFramerateLookup = array(0, 23.976, 24, 25, 29.97, 30, 50, 59.94, 60); |
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276 | return (isset($MPEGvideoFramerateLookup[$rawframerate]) ? (float) $MPEGvideoFramerateLookup[$rawframerate] : (float) 0); |
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277 | } |
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278 | |
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279 | function MPEGvideoAspectRatioLookup($rawaspectratio) { |
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280 | $MPEGvideoAspectRatioLookup = array(0, 1, 0.6735, 0.7031, 0.7615, 0.8055, 0.8437, 0.8935, 0.9157, 0.9815, 1.0255, 1.0695, 1.0950, 1.1575, 1.2015, 0); |
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281 | return (isset($MPEGvideoAspectRatioLookup[$rawaspectratio]) ? (float) $MPEGvideoAspectRatioLookup[$rawaspectratio] : (float) 0); |
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282 | } |
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283 | |
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284 | function MPEGvideoAspectRatioTextLookup($rawaspectratio) { |
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285 | $MPEGvideoAspectRatioTextLookup = array('forbidden', 'square pixels', '0.6735', '16:9, 625 line, PAL', '0.7615', '0.8055', '16:9, 525 line, NTSC', '0.8935', '4:3, 625 line, PAL, CCIR601', '0.9815', '1.0255', '1.0695', '4:3, 525 line, NTSC, CCIR601', '1.1575', '1.2015', 'reserved'); |
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286 | return (isset($MPEGvideoAspectRatioTextLookup[$rawaspectratio]) ? $MPEGvideoAspectRatioTextLookup[$rawaspectratio] : ''); |
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287 | } |
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288 | |
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289 | } |
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290 | |
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291 | |
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292 | ?> |
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