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Code source de LifeType 1.2.4 |
1 <?php 2 ///////////////////////////////////////////////////////////////// 3 /// getID3() by James Heinrich <info@getid3.org> // 4 // available at http://getid3.sourceforge.net // 5 // or http://www.getid3.org // 6 ///////////////////////////////////////////////////////////////// 7 // See readme.txt for more details // 8 ///////////////////////////////////////////////////////////////// 9 // // 10 // module.audio-video.mpeg.php // 11 // module for analyzing MPEG files // 12 // dependencies: module.audio.mp3.php // 13 // /// 14 ///////////////////////////////////////////////////////////////// 15 16 getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio.mp3.php', __FILE__, true); 17 18 define('GETID3_MPEG_VIDEO_PICTURE_START', "\x00\x00\x01\x00"); 19 define('GETID3_MPEG_VIDEO_USER_DATA_START', "\x00\x00\x01\xB2"); 20 define('GETID3_MPEG_VIDEO_SEQUENCE_HEADER', "\x00\x00\x01\xB3"); 21 define('GETID3_MPEG_VIDEO_SEQUENCE_ERROR', "\x00\x00\x01\xB4"); 22 define('GETID3_MPEG_VIDEO_EXTENSION_START', "\x00\x00\x01\xB5"); 23 define('GETID3_MPEG_VIDEO_SEQUENCE_END', "\x00\x00\x01\xB7"); 24 define('GETID3_MPEG_VIDEO_GROUP_START', "\x00\x00\x01\xB8"); 25 define('GETID3_MPEG_AUDIO_START', "\x00\x00\x01\xC0"); 26 27 28 class getid3_mpeg 29 { 30 31 function getid3_mpeg(&$fd, &$ThisFileInfo) { 32 if ($ThisFileInfo['avdataend'] <= $ThisFileInfo['avdataoffset']) { 33 $ThisFileInfo['error'][] = '"avdataend" ('.$ThisFileInfo['avdataend'].') is unexpectedly less-than-or-equal-to "avdataoffset" ('.$ThisFileInfo['avdataoffset'].')'; 34 return false; 35 } 36 $ThisFileInfo['fileformat'] = 'mpeg'; 37 fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET); 38 $MPEGstreamData = fread($fd, min(100000, $ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset'])); 39 $MPEGstreamDataLength = strlen($MPEGstreamData); 40 41 $foundVideo = true; 42 $VideoChunkOffset = 0; 43 while (substr($MPEGstreamData, $VideoChunkOffset++, 4) !== GETID3_MPEG_VIDEO_SEQUENCE_HEADER) { 44 if ($VideoChunkOffset >= $MPEGstreamDataLength) { 45 $foundVideo = false; 46 break; 47 } 48 } 49 if ($foundVideo) { 50 51 // Start code 32 bits 52 // horizontal frame size 12 bits 53 // vertical frame size 12 bits 54 // pixel aspect ratio 4 bits 55 // frame rate 4 bits 56 // bitrate 18 bits 57 // marker bit 1 bit 58 // VBV buffer size 10 bits 59 // constrained parameter flag 1 bit 60 // intra quant. matrix flag 1 bit 61 // intra quant. matrix values 512 bits (present if matrix flag == 1) 62 // non-intra quant. matrix flag 1 bit 63 // non-intra quant. matrix values 512 bits (present if matrix flag == 1) 64 65 $ThisFileInfo['video']['dataformat'] = 'mpeg'; 66 67 $VideoChunkOffset += (strlen(GETID3_MPEG_VIDEO_SEQUENCE_HEADER) - 1); 68 69 $FrameSizeDWORD = getid3_lib::BigEndian2Int(substr($MPEGstreamData, $VideoChunkOffset, 3)); 70 $VideoChunkOffset += 3; 71 72 $AspectRatioFrameRateDWORD = getid3_lib::BigEndian2Int(substr($MPEGstreamData, $VideoChunkOffset, 1)); 73 $VideoChunkOffset += 1; 74 75 $assortedinformation = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $VideoChunkOffset, 4)); 76 $VideoChunkOffset += 4; 77 78 $ThisFileInfo['mpeg']['video']['raw']['framesize_horizontal'] = ($FrameSizeDWORD & 0xFFF000) >> 12; // 12 bits for horizontal frame size 79 $ThisFileInfo['mpeg']['video']['raw']['framesize_vertical'] = ($FrameSizeDWORD & 0x000FFF); // 12 bits for vertical frame size 80 $ThisFileInfo['mpeg']['video']['raw']['pixel_aspect_ratio'] = ($AspectRatioFrameRateDWORD & 0xF0) >> 4; 81 $ThisFileInfo['mpeg']['video']['raw']['frame_rate'] = ($AspectRatioFrameRateDWORD & 0x0F); 82 83 $ThisFileInfo['mpeg']['video']['framesize_horizontal'] = $ThisFileInfo['mpeg']['video']['raw']['framesize_horizontal']; 84 $ThisFileInfo['mpeg']['video']['framesize_vertical'] = $ThisFileInfo['mpeg']['video']['raw']['framesize_vertical']; 85 86 $ThisFileInfo['mpeg']['video']['pixel_aspect_ratio'] = $this->MPEGvideoAspectRatioLookup($ThisFileInfo['mpeg']['video']['raw']['pixel_aspect_ratio']); 87 $ThisFileInfo['mpeg']['video']['pixel_aspect_ratio_text'] = $this->MPEGvideoAspectRatioTextLookup($ThisFileInfo['mpeg']['video']['raw']['pixel_aspect_ratio']); 88 $ThisFileInfo['mpeg']['video']['frame_rate'] = $this->MPEGvideoFramerateLookup($ThisFileInfo['mpeg']['video']['raw']['frame_rate']); 89 90 $ThisFileInfo['mpeg']['video']['raw']['bitrate'] = getid3_lib::Bin2Dec(substr($assortedinformation, 0, 18)); 91 $ThisFileInfo['mpeg']['video']['raw']['marker_bit'] = (bool) getid3_lib::Bin2Dec(substr($assortedinformation, 18, 1)); 92 $ThisFileInfo['mpeg']['video']['raw']['vbv_buffer_size'] = getid3_lib::Bin2Dec(substr($assortedinformation, 19, 10)); 93 $ThisFileInfo['mpeg']['video']['raw']['constrained_param_flag'] = (bool) getid3_lib::Bin2Dec(substr($assortedinformation, 29, 1)); 94 $ThisFileInfo['mpeg']['video']['raw']['intra_quant_flag'] = (bool) getid3_lib::Bin2Dec(substr($assortedinformation, 30, 1)); 95 if ($ThisFileInfo['mpeg']['video']['raw']['intra_quant_flag']) { 96 97 // read 512 bits 98 $ThisFileInfo['mpeg']['video']['raw']['intra_quant'] = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $VideoChunkOffset, 64)); 99 $VideoChunkOffset += 64; 100 101 $ThisFileInfo['mpeg']['video']['raw']['non_intra_quant_flag'] = (bool) getid3_lib::Bin2Dec(substr($ThisFileInfo['mpeg']['video']['raw']['intra_quant'], 511, 1)); 102 $ThisFileInfo['mpeg']['video']['raw']['intra_quant'] = getid3_lib::Bin2Dec(substr($assortedinformation, 31, 1)).substr(getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $VideoChunkOffset, 64)), 0, 511); 103 104 if ($ThisFileInfo['mpeg']['video']['raw']['non_intra_quant_flag']) { 105 $ThisFileInfo['mpeg']['video']['raw']['non_intra_quant'] = substr($MPEGstreamData, $VideoChunkOffset, 64); 106 $VideoChunkOffset += 64; 107 } 108 109 } else { 110 111 $ThisFileInfo['mpeg']['video']['raw']['non_intra_quant_flag'] = (bool) getid3_lib::Bin2Dec(substr($assortedinformation, 31, 1)); 112 if ($ThisFileInfo['mpeg']['video']['raw']['non_intra_quant_flag']) { 113 $ThisFileInfo['mpeg']['video']['raw']['non_intra_quant'] = substr($MPEGstreamData, $VideoChunkOffset, 64); 114 $VideoChunkOffset += 64; 115 } 116 117 } 118 119 if ($ThisFileInfo['mpeg']['video']['raw']['bitrate'] == 0x3FFFF) { // 18 set bits 120 121 $ThisFileInfo['warning'][] = 'This version of getID3() ['.GETID3_VERSION.'] cannot determine average bitrate of VBR MPEG video files'; 122 $ThisFileInfo['mpeg']['video']['bitrate_mode'] = 'vbr'; 123 124 } else { 125 126 $ThisFileInfo['mpeg']['video']['bitrate'] = $ThisFileInfo['mpeg']['video']['raw']['bitrate'] * 400; 127 $ThisFileInfo['mpeg']['video']['bitrate_mode'] = 'cbr'; 128 $ThisFileInfo['video']['bitrate'] = $ThisFileInfo['mpeg']['video']['bitrate']; 129 130 } 131 132 $ThisFileInfo['video']['resolution_x'] = $ThisFileInfo['mpeg']['video']['framesize_horizontal']; 133 $ThisFileInfo['video']['resolution_y'] = $ThisFileInfo['mpeg']['video']['framesize_vertical']; 134 $ThisFileInfo['video']['frame_rate'] = $ThisFileInfo['mpeg']['video']['frame_rate']; 135 $ThisFileInfo['video']['bitrate_mode'] = $ThisFileInfo['mpeg']['video']['bitrate_mode']; 136 $ThisFileInfo['video']['pixel_aspect_ratio'] = $ThisFileInfo['mpeg']['video']['pixel_aspect_ratio']; 137 $ThisFileInfo['video']['lossless'] = false; 138 $ThisFileInfo['video']['bits_per_sample'] = 24; 139 140 } else { 141 142 $ThisFileInfo['error'][] = 'Could not find start of video block in the first 100,000 bytes (or before end of file) - this might not be an MPEG-video file?'; 143 144 } 145 146 //0x000001B3 begins the sequence_header of every MPEG video stream. 147 //But in MPEG-2, this header must immediately be followed by an 148 //extension_start_code (0x000001B5) with a sequence_extension ID (1). 149 //(This extension contains all the additional MPEG-2 stuff.) 150 //MPEG-1 doesn't have this extension, so that's a sure way to tell the 151 //difference between MPEG-1 and MPEG-2 video streams. 152 153 if (substr($MPEGstreamData, $VideoChunkOffset, 4) == GETID3_MPEG_VIDEO_EXTENSION_START) { 154 $ThisFileInfo['video']['codec'] = 'MPEG-2'; 155 } else { 156 $ThisFileInfo['video']['codec'] = 'MPEG-1'; 157 } 158 159 160 $AudioChunkOffset = 0; 161 while (true) { 162 while (substr($MPEGstreamData, $AudioChunkOffset++, 4) !== GETID3_MPEG_AUDIO_START) { 163 if ($AudioChunkOffset >= $MPEGstreamDataLength) { 164 break 2; 165 } 166 } 167 168 for ($i = 0; $i <= 7; $i++) { 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 170 // I have no idea why or what the difference is, so this is a stupid hack. 171 // If anybody has any better idea of what's going on, please let me know - info@getid3.org 172 173 $dummy = $ThisFileInfo; 174 if (getid3_mp3::decodeMPEGaudioHeader($fd, ($AudioChunkOffset + 3) + 8 + $i, $dummy, false)) { 175 $ThisFileInfo = $dummy; 176 $ThisFileInfo['audio']['bitrate_mode'] = 'cbr'; 177 $ThisFileInfo['audio']['lossless'] = false; 178 break 2; 179 180 } 181 } 182 } 183 184 // Temporary hack to account for interleaving overhead: 185 if (!empty($ThisFileInfo['video']['bitrate']) && !empty($ThisFileInfo['audio']['bitrate'])) { 186 $ThisFileInfo['playtime_seconds'] = (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8) / ($ThisFileInfo['video']['bitrate'] + $ThisFileInfo['audio']['bitrate']); 187 188 // Interleaved MPEG audio/video files have a certain amount of overhead that varies 189 // by both video and audio bitrates, and not in any sensible, linear/logarithmic patter 190 // Use interpolated lookup tables to approximately guess how much is overhead, because 191 // playtime is calculated as filesize / total-bitrate 192 $ThisFileInfo['playtime_seconds'] *= $this->MPEGsystemNonOverheadPercentage($ThisFileInfo['video']['bitrate'], $ThisFileInfo['audio']['bitrate']); 193 194 //switch ($ThisFileInfo['video']['bitrate']) { 195 // case('5000000'): 196 // $multiplier = 0.93292642112380355828048824319889; 197 // break; 198 // case('5500000'): 199 // $multiplier = 0.93582895375200989965359777343219; 200 // break; 201 // case('6000000'): 202 // $multiplier = 0.93796247714820932532911373859139; 203 // break; 204 // case('7000000'): 205 // $multiplier = 0.9413264083635103463010117778776; 206 // break; 207 // default: 208 // $multiplier = 1; 209 // break; 210 //} 211 //$ThisFileInfo['playtime_seconds'] *= $multiplier; 212 //$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.'; 213 if ($ThisFileInfo['video']['bitrate'] < 50000) { 214 $ThisFileInfo['warning'][] = 'Interleaved MPEG audio/video playtime may be slightly inaccurate for video bitrates below 100kbps. Except in extreme low-bitrate situations, error should be less than 1%. Report to info@getid3.org if greater than this.'; 215 } 216 } 217 218 return true; 219 } 220 221 222 function MPEGsystemNonOverheadPercentage($VideoBitrate, $AudioBitrate) { 223 $OverheadPercentage = 0; 224 225 $AudioBitrate = max(min($AudioBitrate / 1000, 384), 32); // limit to range of 32kbps - 384kbps (should be only legal bitrates, but maybe VBR?) 226 $VideoBitrate = max(min($VideoBitrate / 1000, 10000), 10); // limit to range of 10kbps - 10Mbps (beyond that curves flatten anyways, no big loss) 227 228 229 //OMBB[audiobitrate] = array(video-10kbps, video-100kbps, video-1000kbps, video-10000kbps) 230 $OverheadMultiplierByBitrate[32] = array(0, 0.9676287944368530, 0.9802276264360310, 0.9844916183244460, 0.9852821845179940); 231 $OverheadMultiplierByBitrate[48] = array(0, 0.9779100089209830, 0.9787770035359320, 0.9846738664076130, 0.9852683013799960); 232 $OverheadMultiplierByBitrate[56] = array(0, 0.9731249855367600, 0.9776624308938040, 0.9832606361852130, 0.9843922606633340); 233 $OverheadMultiplierByBitrate[64] = array(0, 0.9755642683275760, 0.9795256705493390, 0.9836573009193170, 0.9851122539404470); 234 $OverheadMultiplierByBitrate[96] = array(0, 0.9788025247497290, 0.9798553314148700, 0.9822956869792560, 0.9834815119124690); 235 $OverheadMultiplierByBitrate[128] = array(0, 0.9816940050925480, 0.9821675936072120, 0.9829756927470870, 0.9839763420152050); 236 $OverheadMultiplierByBitrate[160] = array(0, 0.9825894094561180, 0.9820913399073960, 0.9823907143253970, 0.9832821783651570); 237 $OverheadMultiplierByBitrate[192] = array(0, 0.9832038474336260, 0.9825731694317960, 0.9821028622712400, 0.9828262076447620); 238 $OverheadMultiplierByBitrate[224] = array(0, 0.9836516298538770, 0.9824718601823890, 0.9818302180625380, 0.9823735101626480); 239 $OverheadMultiplierByBitrate[256] = array(0, 0.9845863022094920, 0.9837229411967540, 0.9824521662210830, 0.9828645172100790); 240 $OverheadMultiplierByBitrate[320] = array(0, 0.9849565280263180, 0.9837683142805110, 0.9822885275960400, 0.9824424382727190); 241 $OverheadMultiplierByBitrate[384] = array(0, 0.9856094774357600, 0.9844573394432720, 0.9825970399837330, 0.9824673808303890); 242 243 $BitrateToUseMin = 32; 244 $BitrateToUseMax = 32; 245 $previousBitrate = 32; 246 foreach ($OverheadMultiplierByBitrate as $key => $value) { 247 if ($AudioBitrate >= $previousBitrate) { 248 $BitrateToUseMin = $previousBitrate; 249 } 250 if ($AudioBitrate < $key) { 251 $BitrateToUseMax = $key; 252 break; 253 } 254 $previousBitrate = $key; 255 } 256 $FactorA = ($BitrateToUseMax - $AudioBitrate) / ($BitrateToUseMax - $BitrateToUseMin); 257 258 $VideoBitrateLog10 = log10($VideoBitrate); 259 $VideoFactorMin1 = $OverheadMultiplierByBitrate[$BitrateToUseMin][floor($VideoBitrateLog10)]; 260 $VideoFactorMin2 = $OverheadMultiplierByBitrate[$BitrateToUseMax][floor($VideoBitrateLog10)]; 261 $VideoFactorMax1 = $OverheadMultiplierByBitrate[$BitrateToUseMin][ceil($VideoBitrateLog10)]; 262 $VideoFactorMax2 = $OverheadMultiplierByBitrate[$BitrateToUseMax][ceil($VideoBitrateLog10)]; 263 $FactorV = $VideoBitrateLog10 - floor($VideoBitrateLog10); 264 265 $OverheadPercentage = $VideoFactorMin1 * $FactorA * $FactorV; 266 $OverheadPercentage += $VideoFactorMin2 * (1 - $FactorA) * $FactorV; 267 $OverheadPercentage += $VideoFactorMax1 * $FactorA * (1 - $FactorV); 268 $OverheadPercentage += $VideoFactorMax2 * (1 - $FactorA) * (1 - $FactorV); 269 270 return $OverheadPercentage; 271 } 272 273 274 function MPEGvideoFramerateLookup($rawframerate) { 275 $MPEGvideoFramerateLookup = array(0, 23.976, 24, 25, 29.97, 30, 50, 59.94, 60); 276 return (isset($MPEGvideoFramerateLookup[$rawframerate]) ? (float) $MPEGvideoFramerateLookup[$rawframerate] : (float) 0); 277 } 278 279 function MPEGvideoAspectRatioLookup($rawaspectratio) { 280 $MPEGvideoAspectRatioLookup = array(0, 1, 0.6735, 0.7031, 0.7615, 0.8055, 0.8437, 0.8935, 0.9157, 0.9815, 1.0255, 1.0695, 1.0950, 1.1575, 1.2015, 0); 281 return (isset($MPEGvideoAspectRatioLookup[$rawaspectratio]) ? (float) $MPEGvideoAspectRatioLookup[$rawaspectratio] : (float) 0); 282 } 283 284 function MPEGvideoAspectRatioTextLookup($rawaspectratio) { 285 $MPEGvideoAspectRatioTextLookup = array('forbidden', 'square pixels', '0.6735', '16:9, 625 line, PAL', '0.7615', '0.8055', '16:9, 525 line, NTSC', '0.8935', '4:3, 625 line, PAL, CCIR601', '0.9815', '1.0255', '1.0695', '4:3, 525 line, NTSC, CCIR601', '1.1575', '1.2015', 'reserved'); 286 return (isset($MPEGvideoAspectRatioTextLookup[$rawaspectratio]) ? $MPEGvideoAspectRatioTextLookup[$rawaspectratio] : ''); 287 } 288 289 } 290 291 292 ?>
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| Généré le : Mon Nov 26 21:04:15 2007 | par Balluche grâce à PHPXref 0.7 |
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