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File: includes/getid3/module.audio-video.mpeg.php

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  Classes of Karl Holz   WaldScan   includes/getid3/module.audio-video.mpeg.php   Download  
File: includes/getid3/module.audio-video.mpeg.php
Role: Auxiliary script
Content type: text/plain
Description: getID3 dependency
Class: WaldScan
Scan directories for files with certain extensions
Author: By
Last change: Update of includes/getid3/module.audio-video.mpeg.php
Date: 1 year ago
Size: 15,580 bytes
 

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<?php ///////////////////////////////////////////////////////////////// /// getID3() by James Heinrich <info@getid3.org> // // available at http://getid3.sourceforge.net // // or http://www.getid3.org // ///////////////////////////////////////////////////////////////// // See readme.txt for more details // ///////////////////////////////////////////////////////////////// // // // module.audio-video.mpeg.php // // module for analyzing MPEG files // // dependencies: module.audio.mp3.php // // /// ///////////////////////////////////////////////////////////////// getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio.mp3.php', __FILE__, true); define('GETID3_MPEG_VIDEO_PICTURE_START', "\x00\x00\x01\x00"); define('GETID3_MPEG_VIDEO_USER_DATA_START', "\x00\x00\x01\xB2"); define('GETID3_MPEG_VIDEO_SEQUENCE_HEADER', "\x00\x00\x01\xB3"); define('GETID3_MPEG_VIDEO_SEQUENCE_ERROR', "\x00\x00\x01\xB4"); define('GETID3_MPEG_VIDEO_EXTENSION_START', "\x00\x00\x01\xB5"); define('GETID3_MPEG_VIDEO_SEQUENCE_END', "\x00\x00\x01\xB7"); define('GETID3_MPEG_VIDEO_GROUP_START', "\x00\x00\x01\xB8"); define('GETID3_MPEG_AUDIO_START', "\x00\x00\x01\xC0"); class getid3_mpeg extends getid3_handler { function Analyze() { $info = &$this->getid3->info; if ($info['avdataend'] <= $info['avdataoffset']) { $info['error'][] = '"avdataend" ('.$info['avdataend'].') is unexpectedly less-than-or-equal-to "avdataoffset" ('.$info['avdataoffset'].')'; return false; } $info['fileformat'] = 'mpeg'; fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET); $MPEGstreamData = fread($this->getid3->fp, min(100000, $info['avdataend'] - $info['avdataoffset'])); $MPEGstreamDataLength = strlen($MPEGstreamData); $foundVideo = true; $VideoChunkOffset = 0; while (substr($MPEGstreamData, $VideoChunkOffset++, 4) !== GETID3_MPEG_VIDEO_SEQUENCE_HEADER) { if ($VideoChunkOffset >= $MPEGstreamDataLength) { $foundVideo = false; break; } } if ($foundVideo) { // Start code 32 bits // horizontal frame size 12 bits // vertical frame size 12 bits // pixel aspect ratio 4 bits // frame rate 4 bits // bitrate 18 bits // marker bit 1 bit // VBV buffer size 10 bits // constrained parameter flag 1 bit // intra quant. matrix flag 1 bit // intra quant. matrix values 512 bits (present if matrix flag == 1) // non-intra quant. matrix flag 1 bit // non-intra quant. matrix values 512 bits (present if matrix flag == 1) $info['video']['dataformat'] = 'mpeg'; $VideoChunkOffset += (strlen(GETID3_MPEG_VIDEO_SEQUENCE_HEADER) - 1); $FrameSizeDWORD = getid3_lib::BigEndian2Int(substr($MPEGstreamData, $VideoChunkOffset, 3)); $VideoChunkOffset += 3; $AspectRatioFrameRateDWORD = getid3_lib::BigEndian2Int(substr($MPEGstreamData, $VideoChunkOffset, 1)); $VideoChunkOffset += 1; $assortedinformation = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $VideoChunkOffset, 4)); $VideoChunkOffset += 4; $info['mpeg']['video']['raw']['framesize_horizontal'] = ($FrameSizeDWORD & 0xFFF000) >> 12; // 12 bits for horizontal frame size $info['mpeg']['video']['raw']['framesize_vertical'] = ($FrameSizeDWORD & 0x000FFF); // 12 bits for vertical frame size $info['mpeg']['video']['raw']['pixel_aspect_ratio'] = ($AspectRatioFrameRateDWORD & 0xF0) >> 4; $info['mpeg']['video']['raw']['frame_rate'] = ($AspectRatioFrameRateDWORD & 0x0F); $info['mpeg']['video']['framesize_horizontal'] = $info['mpeg']['video']['raw']['framesize_horizontal']; $info['mpeg']['video']['framesize_vertical'] = $info['mpeg']['video']['raw']['framesize_vertical']; $info['mpeg']['video']['pixel_aspect_ratio'] = $this->MPEGvideoAspectRatioLookup($info['mpeg']['video']['raw']['pixel_aspect_ratio']); $info['mpeg']['video']['pixel_aspect_ratio_text'] = $this->MPEGvideoAspectRatioTextLookup($info['mpeg']['video']['raw']['pixel_aspect_ratio']); $info['mpeg']['video']['frame_rate'] = $this->MPEGvideoFramerateLookup($info['mpeg']['video']['raw']['frame_rate']); $info['mpeg']['video']['raw']['bitrate'] = getid3_lib::Bin2Dec(substr($assortedinformation, 0, 18)); $info['mpeg']['video']['raw']['marker_bit'] = (bool) getid3_lib::Bin2Dec(substr($assortedinformation, 18, 1)); $info['mpeg']['video']['raw']['vbv_buffer_size'] = getid3_lib::Bin2Dec(substr($assortedinformation, 19, 10)); $info['mpeg']['video']['raw']['constrained_param_flag'] = (bool) getid3_lib::Bin2Dec(substr($assortedinformation, 29, 1)); $info['mpeg']['video']['raw']['intra_quant_flag'] = (bool) getid3_lib::Bin2Dec(substr($assortedinformation, 30, 1)); if ($info['mpeg']['video']['raw']['intra_quant_flag']) { // read 512 bits $info['mpeg']['video']['raw']['intra_quant'] = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $VideoChunkOffset, 64)); $VideoChunkOffset += 64; $info['mpeg']['video']['raw']['non_intra_quant_flag'] = (bool) getid3_lib::Bin2Dec(substr($info['mpeg']['video']['raw']['intra_quant'], 511, 1)); $info['mpeg']['video']['raw']['intra_quant'] = getid3_lib::Bin2Dec(substr($assortedinformation, 31, 1)).substr(getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $VideoChunkOffset, 64)), 0, 511); if ($info['mpeg']['video']['raw']['non_intra_quant_flag']) { $info['mpeg']['video']['raw']['non_intra_quant'] = substr($MPEGstreamData, $VideoChunkOffset, 64); $VideoChunkOffset += 64; } } else { $info['mpeg']['video']['raw']['non_intra_quant_flag'] = (bool) getid3_lib::Bin2Dec(substr($assortedinformation, 31, 1)); if ($info['mpeg']['video']['raw']['non_intra_quant_flag']) { $info['mpeg']['video']['raw']['non_intra_quant'] = substr($MPEGstreamData, $VideoChunkOffset, 64); $VideoChunkOffset += 64; } } if ($info['mpeg']['video']['raw']['bitrate'] == 0x3FFFF) { // 18 set bits $info['warning'][] = 'This version of getID3() ['.$this->getid3->version().'] cannot determine average bitrate of VBR MPEG video files'; $info['mpeg']['video']['bitrate_mode'] = 'vbr'; } else { $info['mpeg']['video']['bitrate'] = $info['mpeg']['video']['raw']['bitrate'] * 400; $info['mpeg']['video']['bitrate_mode'] = 'cbr'; $info['video']['bitrate'] = $info['mpeg']['video']['bitrate']; } $info['video']['resolution_x'] = $info['mpeg']['video']['framesize_horizontal']; $info['video']['resolution_y'] = $info['mpeg']['video']['framesize_vertical']; $info['video']['frame_rate'] = $info['mpeg']['video']['frame_rate']; $info['video']['bitrate_mode'] = $info['mpeg']['video']['bitrate_mode']; $info['video']['pixel_aspect_ratio'] = $info['mpeg']['video']['pixel_aspect_ratio']; $info['video']['lossless'] = false; $info['video']['bits_per_sample'] = 24; } else { $info['error'][] = 'Could not find start of video block in the first 100,000 bytes (or before end of file) - this might not be an MPEG-video file?'; } //0x000001B3 begins the sequence_header of every MPEG video stream. //But in MPEG-2, this header must immediately be followed by an //extension_start_code (0x000001B5) with a sequence_extension ID (1). //(This extension contains all the additional MPEG-2 stuff.) //MPEG-1 doesn't have this extension, so that's a sure way to tell the //difference between MPEG-1 and MPEG-2 video streams. if (substr($MPEGstreamData, $VideoChunkOffset, 4) == GETID3_MPEG_VIDEO_EXTENSION_START) { $info['video']['codec'] = 'MPEG-2'; } else { $info['video']['codec'] = 'MPEG-1'; } $AudioChunkOffset = 0; while (true) { while (substr($MPEGstreamData, $AudioChunkOffset++, 4) !== GETID3_MPEG_AUDIO_START) { if ($AudioChunkOffset >= $MPEGstreamDataLength) { break 2; } } $getid3_temp = new getID3(); $getid3_temp->openfile($this->getid3->filename); $getid3_temp->info = $info; $getid3_mp3 = new getid3_mp3($getid3_temp); for ($i = 0; $i <= 7; $i++) { // some files have the MPEG-audio header 8 bytes after the end of the $00 $00 $01 $C0 signature, some have it up to 13 bytes (or more?) after // I have no idea why or what the difference is, so this is a stupid hack. // If anybody has any better idea of what's going on, please let me know - info@getid3.org fseek($getid3_temp->fp, ftell($this->getid3->fp), SEEK_SET); $getid3_temp->info = $info; // only overwrite real data if valid header found if ($getid3_mp3->decodeMPEGaudioHeader(($AudioChunkOffset + 3) + 8 + $i, $getid3_temp->info, false)) { $info = $getid3_temp->info; $info['audio']['bitrate_mode'] = 'cbr'; $info['audio']['lossless'] = false; unset($getid3_temp, $getid3_mp3); break 2; } } unset($getid3_temp, $getid3_mp3); } // Temporary hack to account for interleaving overhead: if (!empty($info['video']['bitrate']) && !empty($info['audio']['bitrate'])) { $info['playtime_seconds'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / ($info['video']['bitrate'] + $info['audio']['bitrate']); // Interleaved MPEG audio/video files have a certain amount of overhead that varies // by both video and audio bitrates, and not in any sensible, linear/logarithmic patter // Use interpolated lookup tables to approximately guess how much is overhead, because // playtime is calculated as filesize / total-bitrate $info['playtime_seconds'] *= $this->MPEGsystemNonOverheadPercentage($info['video']['bitrate'], $info['audio']['bitrate']); //switch ($info['video']['bitrate']) { // case('5000000'): // $multiplier = 0.93292642112380355828048824319889; // break; // case('5500000'): // $multiplier = 0.93582895375200989965359777343219; // break; // case('6000000'): // $multiplier = 0.93796247714820932532911373859139; // break; // case('7000000'): // $multiplier = 0.9413264083635103463010117778776; // break; // default: // $multiplier = 1; // break; //} //$info['playtime_seconds'] *= $multiplier; //$info['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.'; if ($info['video']['bitrate'] < 50000) { $info['warning'][] = 'Interleaved MPEG audio/video playtime may be slightly inaccurate for video bitrates below 100kbps. Except in extreme low-bitrate situations, error should be less than 1%. Report to info@getid3.org if greater than this.'; } } return true; } function MPEGsystemNonOverheadPercentage($VideoBitrate, $AudioBitrate) { $OverheadPercentage = 0; $AudioBitrate = max(min($AudioBitrate / 1000, 384), 32); // limit to range of 32kbps - 384kbps (should be only legal bitrates, but maybe VBR?) $VideoBitrate = max(min($VideoBitrate / 1000, 10000), 10); // limit to range of 10kbps - 10Mbps (beyond that curves flatten anyways, no big loss) //OMBB[audiobitrate] = array(video-10kbps, video-100kbps, video-1000kbps, video-10000kbps) $OverheadMultiplierByBitrate[32] = array(0, 0.9676287944368530, 0.9802276264360310, 0.9844916183244460, 0.9852821845179940); $OverheadMultiplierByBitrate[48] = array(0, 0.9779100089209830, 0.9787770035359320, 0.9846738664076130, 0.9852683013799960); $OverheadMultiplierByBitrate[56] = array(0, 0.9731249855367600, 0.9776624308938040, 0.9832606361852130, 0.9843922606633340); $OverheadMultiplierByBitrate[64] = array(0, 0.9755642683275760, 0.9795256705493390, 0.9836573009193170, 0.9851122539404470); $OverheadMultiplierByBitrate[96] = array(0, 0.9788025247497290, 0.9798553314148700, 0.9822956869792560, 0.9834815119124690); $OverheadMultiplierByBitrate[128] = array(0, 0.9816940050925480, 0.9821675936072120, 0.9829756927470870, 0.9839763420152050); $OverheadMultiplierByBitrate[160] = array(0, 0.9825894094561180, 0.9820913399073960, 0.9823907143253970, 0.9832821783651570); $OverheadMultiplierByBitrate[192] = array(0, 0.9832038474336260, 0.9825731694317960, 0.9821028622712400, 0.9828262076447620); $OverheadMultiplierByBitrate[224] = array(0, 0.9836516298538770, 0.9824718601823890, 0.9818302180625380, 0.9823735101626480); $OverheadMultiplierByBitrate[256] = array(0, 0.9845863022094920, 0.9837229411967540, 0.9824521662210830, 0.9828645172100790); $OverheadMultiplierByBitrate[320] = array(0, 0.9849565280263180, 0.9837683142805110, 0.9822885275960400, 0.9824424382727190); $OverheadMultiplierByBitrate[384] = array(0, 0.9856094774357600, 0.9844573394432720, 0.9825970399837330, 0.9824673808303890); $BitrateToUseMin = 32; $BitrateToUseMax = 32; $previousBitrate = 32; foreach ($OverheadMultiplierByBitrate as $key => $value) { if ($AudioBitrate >= $previousBitrate) { $BitrateToUseMin = $previousBitrate; } if ($AudioBitrate < $key) { $BitrateToUseMax = $key; break; } $previousBitrate = $key; } $FactorA = ($BitrateToUseMax - $AudioBitrate) / ($BitrateToUseMax - $BitrateToUseMin); $VideoBitrateLog10 = log10($VideoBitrate); $VideoFactorMin1 = $OverheadMultiplierByBitrate[$BitrateToUseMin][floor($VideoBitrateLog10)]; $VideoFactorMin2 = $OverheadMultiplierByBitrate[$BitrateToUseMax][floor($VideoBitrateLog10)]; $VideoFactorMax1 = $OverheadMultiplierByBitrate[$BitrateToUseMin][ceil($VideoBitrateLog10)]; $VideoFactorMax2 = $OverheadMultiplierByBitrate[$BitrateToUseMax][ceil($VideoBitrateLog10)]; $FactorV = $VideoBitrateLog10 - floor($VideoBitrateLog10); $OverheadPercentage = $VideoFactorMin1 * $FactorA * $FactorV; $OverheadPercentage += $VideoFactorMin2 * (1 - $FactorA) * $FactorV; $OverheadPercentage += $VideoFactorMax1 * $FactorA * (1 - $FactorV); $OverheadPercentage += $VideoFactorMax2 * (1 - $FactorA) * (1 - $FactorV); return $OverheadPercentage; } function MPEGvideoFramerateLookup($rawframerate) { $MPEGvideoFramerateLookup = array(0, 23.976, 24, 25, 29.97, 30, 50, 59.94, 60); return (isset($MPEGvideoFramerateLookup[$rawframerate]) ? (float) $MPEGvideoFramerateLookup[$rawframerate] : (float) 0); } function MPEGvideoAspectRatioLookup($rawaspectratio) { $MPEGvideoAspectRatioLookup = array(0, 1, 0.6735, 0.7031, 0.7615, 0.8055, 0.8437, 0.8935, 0.9157, 0.9815, 1.0255, 1.0695, 1.0950, 1.1575, 1.2015, 0); return (isset($MPEGvideoAspectRatioLookup[$rawaspectratio]) ? (float) $MPEGvideoAspectRatioLookup[$rawaspectratio] : (float) 0); } function MPEGvideoAspectRatioTextLookup($rawaspectratio) { $MPEGvideoAspectRatioTextLookup = array('forbidden', 'square pixels', '0.6735', '16:9, 625 line, PAL', '0.7615', '0.8055', '16:9, 525 line, NTSC', '0.8935', '4:3, 625 line, PAL, CCIR601', '0.9815', '1.0255', '1.0695', '4:3, 525 line, NTSC, CCIR601', '1.1575', '1.2015', 'reserved'); return (isset($MPEGvideoAspectRatioTextLookup[$rawaspectratio]) ? $MPEGvideoAspectRatioTextLookup[$rawaspectratio] : ''); } } ?>