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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 " );
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class getid3_mpeg extends getid3_handler
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{
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function Analyze () {
$info = & $this -> getid3 -> info ;
if ( $info [ 'avdataend' ] <= $info [ 'avdataoffset' ]) {
$info [ 'error' ][] = '"avdataend" (' . $info [ 'avdataend' ] . ') is unexpectedly less-than-or-equal-to "avdataoffset" (' . $info [ 'avdataoffset' ] . ')' ;
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return false ;
}
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$info [ 'fileformat' ] = 'mpeg' ;
fseek ( $this -> getid3 -> fp , $info [ 'avdataoffset' ], SEEK_SET );
$MPEGstreamData = fread ( $this -> getid3 -> fp , min ( 100000 , $info [ 'avdataend' ] - $info [ 'avdataoffset' ]));
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$MPEGstreamDataLength = strlen ( $MPEGstreamData );
$foundVideo = true ;
$VideoChunkOffset = 0 ;
while ( substr ( $MPEGstreamData , $VideoChunkOffset ++ , 4 ) !== GETID3_MPEG_VIDEO_SEQUENCE_HEADER ) {
if ( $VideoChunkOffset >= $MPEGstreamDataLength ) {
$foundVideo = false ;
break ;
}
}
if ( $foundVideo ) {
// Start code 32 bits
// horizontal frame size 12 bits
// vertical frame size 12 bits
// pixel aspect ratio 4 bits
// frame rate 4 bits
// bitrate 18 bits
// marker bit 1 bit
// VBV buffer size 10 bits
// constrained parameter flag 1 bit
// intra quant. matrix flag 1 bit
// intra quant. matrix values 512 bits (present if matrix flag == 1)
// non-intra quant. matrix flag 1 bit
// non-intra quant. matrix values 512 bits (present if matrix flag == 1)
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$info [ 'video' ][ 'dataformat' ] = 'mpeg' ;
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$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 ));
$VideoChunkOffset += 4 ;
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$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' ] = ( $AspectRatioFrameRateDWORD & 0x0F );
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$info [ 'mpeg' ][ 'video' ][ 'framesize_horizontal' ] = $info [ 'mpeg' ][ 'video' ][ 'raw' ][ 'framesize_horizontal' ];
$info [ 'mpeg' ][ 'video' ][ 'framesize_vertical' ] = $info [ 'mpeg' ][ 'video' ][ 'raw' ][ 'framesize_vertical' ];
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$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 ( $info [ 'mpeg' ][ 'video' ][ 'raw' ][ 'frame_rate' ]);
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$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 ( $info [ 'mpeg' ][ 'video' ][ 'raw' ][ 'intra_quant_flag' ]) {
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// read 512 bits
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$info [ 'mpeg' ][ 'video' ][ 'raw' ][ 'intra_quant' ] = getid3_lib :: BigEndian2Bin ( substr ( $MPEGstreamData , $VideoChunkOffset , 64 ));
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$VideoChunkOffset += 64 ;
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$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 );
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if ( $info [ 'mpeg' ][ 'video' ][ 'raw' ][ 'non_intra_quant_flag' ]) {
$info [ 'mpeg' ][ 'video' ][ 'raw' ][ 'non_intra_quant' ] = substr ( $MPEGstreamData , $VideoChunkOffset , 64 );
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$VideoChunkOffset += 64 ;
}
} else {
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$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 , $VideoChunkOffset , 64 );
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$VideoChunkOffset += 64 ;
}
}
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if ( $info [ 'mpeg' ][ 'video' ][ 'raw' ][ 'bitrate' ] == 0x3FFFF ) { // 18 set bits
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$info [ 'warning' ][] = 'This version of getID3() [' . $this -> getid3 -> version () . '] cannot determine average bitrate of VBR MPEG video files' ;
$info [ 'mpeg' ][ 'video' ][ 'bitrate_mode' ] = 'vbr' ;
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} else {
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$info [ 'mpeg' ][ 'video' ][ 'bitrate' ] = $info [ 'mpeg' ][ 'video' ][ 'raw' ][ 'bitrate' ] * 400 ;
$info [ 'mpeg' ][ 'video' ][ 'bitrate_mode' ] = 'cbr' ;
$info [ 'video' ][ 'bitrate' ] = $info [ 'mpeg' ][ 'video' ][ 'bitrate' ];
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}
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$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 ;
$info [ 'video' ][ 'bits_per_sample' ] = 24 ;
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} else {
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$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?' ;
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}
//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 , $VideoChunkOffset , 4 ) == GETID3_MPEG_VIDEO_EXTENSION_START ) {
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$info [ 'video' ][ 'codec' ] = 'MPEG-2' ;
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} else {
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$info [ 'video' ][ 'codec' ] = 'MPEG-1' ;
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}
$AudioChunkOffset = 0 ;
while ( true ) {
while ( substr ( $MPEGstreamData , $AudioChunkOffset ++ , 4 ) !== GETID3_MPEG_AUDIO_START ) {
if ( $AudioChunkOffset >= $MPEGstreamDataLength ) {
break 2 ;
}
}
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$getid3_temp = new getID3 ();
$getid3_temp -> openfile ( $this -> getid3 -> filename );
$getid3_temp -> info = $info ;
$getid3_mp3 = new getid3_mp3 ( $getid3_temp );
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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
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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 );
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break 2 ;
}
}
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unset ( $getid3_temp , $getid3_mp3 );
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}
// Temporary hack to account for interleaving overhead:
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if ( ! empty ( $info [ 'video' ][ 'bitrate' ]) && ! empty ( $info [ 'audio' ][ 'bitrate' ])) {
$info [ 'playtime_seconds' ] = (( $info [ 'avdataend' ] - $info [ 'avdataoffset' ]) * 8 ) / ( $info [ 'video' ][ 'bitrate' ] + $info [ 'audio' ][ 'bitrate' ]);
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// Interleaved MPEG audio/video files have a certain amount of overhead that varies
// by both video and audio bitrates, and not in any sensible, linear/logarithmic patter
// Use interpolated lookup tables to approximately guess how much is overhead, because
// playtime is calculated as filesize / total-bitrate
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$info [ 'playtime_seconds' ] *= $this -> MPEGsystemNonOverheadPercentage ( $info [ 'video' ][ 'bitrate' ], $info [ 'audio' ][ 'bitrate' ]);
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//switch ($info['video']['bitrate']) {
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// 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:
// $multiplier = 1;
// break;
//}
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//$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.' ;
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}
}
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 ] : '' );
}
}
?>