Syntax Syntax
Parameters Parameters
- $startoffset
-
(Required)
- $maxoffset
-
(Required)
Return Return
(array|false)
Source Source
File: wp-includes/ID3/module.audio-video.riff.php
* @throws Exception * @throws getid3_exception */ public function ParseRIFFAMV($startoffset, $maxoffset) { // AMV files are RIFF-AVI files with parts of the spec deliberately broken, such as chunk size fields hardcoded to zero (because players known in hardware that these fields are always a certain size // https://code.google.com/p/amv-codec-tools/wiki/AmvDocumentation //typedef struct _amvmainheader { //FOURCC fcc; // 'amvh' //DWORD cb; //DWORD dwMicroSecPerFrame; //BYTE reserve[28]; //DWORD dwWidth; //DWORD dwHeight; //DWORD dwSpeed; //DWORD reserve0; //DWORD reserve1; //BYTE bTimeSec; //BYTE bTimeMin; //WORD wTimeHour; //} AMVMAINHEADER; $info = &$this->getid3->info; $RIFFchunk = false; try { $this->fseek($startoffset); $maxoffset = min($maxoffset, $info['avdataend']); $AMVheader = $this->fread(284); if (substr($AMVheader, 0, 8) != 'hdrlamvh') { throw new Exception('expecting "hdrlamv" at offset '.($startoffset + 0).', found "'.substr($AMVheader, 0, 8).'"'); } if (substr($AMVheader, 8, 4) != "\x38\x00\x00\x00") { // "amvh" chunk size, hardcoded to 0x38 = 56 bytes throw new Exception('expecting "0x38000000" at offset '.($startoffset + 8).', found "'.getid3_lib::PrintHexBytes(substr($AMVheader, 8, 4)).'"'); } $RIFFchunk = array(); $RIFFchunk['amvh']['us_per_frame'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 12, 4)); $RIFFchunk['amvh']['reserved28'] = substr($AMVheader, 16, 28); // null? reserved? $RIFFchunk['amvh']['resolution_x'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 44, 4)); $RIFFchunk['amvh']['resolution_y'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 48, 4)); $RIFFchunk['amvh']['frame_rate_int'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 52, 4)); $RIFFchunk['amvh']['reserved0'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 56, 4)); // 1? reserved? $RIFFchunk['amvh']['reserved1'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 60, 4)); // 0? reserved? $RIFFchunk['amvh']['runtime_sec'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 64, 1)); $RIFFchunk['amvh']['runtime_min'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 65, 1)); $RIFFchunk['amvh']['runtime_hrs'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 66, 2)); $info['video']['frame_rate'] = 1000000 / $RIFFchunk['amvh']['us_per_frame']; $info['video']['resolution_x'] = $RIFFchunk['amvh']['resolution_x']; $info['video']['resolution_y'] = $RIFFchunk['amvh']['resolution_y']; $info['playtime_seconds'] = ($RIFFchunk['amvh']['runtime_hrs'] * 3600) + ($RIFFchunk['amvh']['runtime_min'] * 60) + $RIFFchunk['amvh']['runtime_sec']; // the rest is all hardcoded(?) and does not appear to be useful until you get to audio info at offset 256, even then everything is probably hardcoded if (substr($AMVheader, 68, 20) != 'LIST'."\x00\x00\x00\x00".'strlstrh'."\x38\x00\x00\x00") { throw new Exception('expecting "LIST<0x00000000>strlstrh<0x38000000>" at offset '.($startoffset + 68).', found "'.getid3_lib::PrintHexBytes(substr($AMVheader, 68, 20)).'"'); } // followed by 56 bytes of null: substr($AMVheader, 88, 56) -> 144 if (substr($AMVheader, 144, 8) != 'strf'."\x24\x00\x00\x00") { throw new Exception('expecting "strf<0x24000000>" at offset '.($startoffset + 144).', found "'.getid3_lib::PrintHexBytes(substr($AMVheader, 144, 8)).'"'); } // followed by 36 bytes of null: substr($AMVheader, 144, 36) -> 180 if (substr($AMVheader, 188, 20) != 'LIST'."\x00\x00\x00\x00".'strlstrh'."\x30\x00\x00\x00") { throw new Exception('expecting "LIST<0x00000000>strlstrh<0x30000000>" at offset '.($startoffset + 188).', found "'.getid3_lib::PrintHexBytes(substr($AMVheader, 188, 20)).'"'); } // followed by 48 bytes of null: substr($AMVheader, 208, 48) -> 256 if (substr($AMVheader, 256, 8) != 'strf'."\x14\x00\x00\x00") { throw new Exception('expecting "strf<0x14000000>" at offset '.($startoffset + 256).', found "'.getid3_lib::PrintHexBytes(substr($AMVheader, 256, 8)).'"'); } // followed by 20 bytes of a modified WAVEFORMATEX: // typedef struct { // WORD wFormatTag; //(Fixme: this is equal to PCM's 0x01 format code) // WORD nChannels; //(Fixme: this is always 1) // DWORD nSamplesPerSec; //(Fixme: for all known sample files this is equal to 22050) // DWORD nAvgBytesPerSec; //(Fixme: for all known sample files this is equal to 44100) // WORD nBlockAlign; //(Fixme: this seems to be 2 in AMV files, is this correct ?) // WORD wBitsPerSample; //(Fixme: this seems to be 16 in AMV files instead of the expected 4) // WORD cbSize; //(Fixme: this seems to be 0 in AMV files) // WORD reserved; // } WAVEFORMATEX; $RIFFchunk['strf']['wformattag'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 264, 2)); $RIFFchunk['strf']['nchannels'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 266, 2)); $RIFFchunk['strf']['nsamplespersec'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 268, 4)); $RIFFchunk['strf']['navgbytespersec'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 272, 4)); $RIFFchunk['strf']['nblockalign'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 276, 2)); $RIFFchunk['strf']['wbitspersample'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 278, 2)); $RIFFchunk['strf']['cbsize'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 280, 2)); $RIFFchunk['strf']['reserved'] = getid3_lib::LittleEndian2Int(substr($AMVheader, 282, 2)); $info['audio']['lossless'] = false; $info['audio']['sample_rate'] = $RIFFchunk['strf']['nsamplespersec']; $info['audio']['channels'] = $RIFFchunk['strf']['nchannels']; $info['audio']['bits_per_sample'] = $RIFFchunk['strf']['wbitspersample']; $info['audio']['bitrate'] = $info['audio']['sample_rate'] * $info['audio']['channels'] * $info['audio']['bits_per_sample']; $info['audio']['bitrate_mode'] = 'cbr'; } catch (getid3_exception $e) { if ($e->getCode() == 10) { $this->warning('RIFFAMV parser: '.$e->getMessage()); } else { throw $e; } }