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author | Alib <aliboba@free.fr> | 2010-03-15 17:56:22 +0100 |
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committer | Alib <aliboba@free.fr> | 2010-03-15 17:56:22 +0100 |
commit | 438912c0c4a4075a5cd74cf9689451c9df4bbe34 (patch) | |
tree | 334e03bbba01b002a34d3cbf81ee7e600ec7bff6 /getid3/module.audio.ac3.php | |
parent | a8012963c23e7e5eaf487ee9e192ae5c4d4ccff2 (diff) | |
download | istreamdev-438912c0c4a4075a5cd74cf9689451c9df4bbe34.tar.gz istreamdev-438912c0c4a4075a5cd74cf9689451c9df4bbe34.tar.bz2 |
New Jquery branch. Initial development version for istreamdev 1.0
Diffstat (limited to 'getid3/module.audio.ac3.php')
-rw-r--r-- | getid3/module.audio.ac3.php | 497 |
1 files changed, 0 insertions, 497 deletions
diff --git a/getid3/module.audio.ac3.php b/getid3/module.audio.ac3.php deleted file mode 100644 index 9809a47..0000000 --- a/getid3/module.audio.ac3.php +++ /dev/null @@ -1,497 +0,0 @@ -<?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.ac3.php // -// module for analyzing AC-3 (aka Dolby Digital) audio files // -// dependencies: NONE // -// /// -///////////////////////////////////////////////////////////////// - - -class getid3_ac3 -{ - - function getid3_ac3(&$fd, &$ThisFileInfo) { - - ///AH - $ThisFileInfo['ac3']['raw']['bsi'] = array(); - $thisfile_ac3 = &$ThisFileInfo['ac3']; - $thisfile_ac3_raw = &$thisfile_ac3['raw']; - $thisfile_ac3_raw_bsi = &$thisfile_ac3_raw['bsi']; - - - // http://www.atsc.org/standards/a_52a.pdf - - $ThisFileInfo['fileformat'] = 'ac3'; - $ThisFileInfo['audio']['dataformat'] = 'ac3'; - $ThisFileInfo['audio']['bitrate_mode'] = 'cbr'; - $ThisFileInfo['audio']['lossless'] = false; - - // An AC-3 serial coded audio bit stream is made up of a sequence of synchronization frames - // Each synchronization frame contains 6 coded audio blocks (AB), each of which represent 256 - // new audio samples per channel. A synchronization information (SI) header at the beginning - // of each frame contains information needed to acquire and maintain synchronization. A - // bit stream information (BSI) header follows SI, and contains parameters describing the coded - // audio service. The coded audio blocks may be followed by an auxiliary data (Aux) field. At the - // end of each frame is an error check field that includes a CRC word for error detection. An - // additional CRC word is located in the SI header, the use of which, by a decoder, is optional. - // - // syncinfo() | bsi() | AB0 | AB1 | AB2 | AB3 | AB4 | AB5 | Aux | CRC - - fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET); - $AC3header['syncinfo'] = fread($fd, 5); - $thisfile_ac3_raw['synchinfo']['synchword'] = substr($AC3header['syncinfo'], 0, 2); - - if ($thisfile_ac3_raw['synchinfo']['synchword'] != "\x0B\x77") { - - $ThisFileInfo['error'][] = 'Expecting "\x0B\x77" at offset '.$ThisFileInfo['avdataoffset'].', found \x'.strtoupper(dechex($AC3header['syncinfo']{0})).'\x'.strtoupper(dechex($AC3header['syncinfo']{1})).' instead'; - unset($thisfile_ac3); - return false; - - } else { - - // syncinfo() { - // syncword 16 - // crc1 16 - // fscod 2 - // frmsizecod 6 - // } /* end of syncinfo */ - - $thisfile_ac3_raw['synchinfo']['crc1'] = getid3_lib::LittleEndian2Int(substr($AC3header['syncinfo'], 2, 2)); - $ac3_synchinfo_fscod_frmsizecod = getid3_lib::LittleEndian2Int(substr($AC3header['syncinfo'], 4, 1)); - $thisfile_ac3_raw['synchinfo']['fscod'] = ($ac3_synchinfo_fscod_frmsizecod & 0xC0) >> 6; - $thisfile_ac3_raw['synchinfo']['frmsizecod'] = ($ac3_synchinfo_fscod_frmsizecod & 0x3F); - - $thisfile_ac3['sample_rate'] = $this->AC3sampleRateCodeLookup($thisfile_ac3_raw['synchinfo']['fscod']); - if ($thisfile_ac3_raw['synchinfo']['fscod'] <= 3) { - $ThisFileInfo['audio']['sample_rate'] = $thisfile_ac3['sample_rate']; - } - - $thisfile_ac3['frame_length'] = $this->AC3frameSizeLookup($thisfile_ac3_raw['synchinfo']['frmsizecod'], $thisfile_ac3_raw['synchinfo']['fscod']); - $thisfile_ac3['bitrate'] = $this->AC3bitrateLookup($thisfile_ac3_raw['synchinfo']['frmsizecod']); - $ThisFileInfo['audio']['bitrate'] = $thisfile_ac3['bitrate']; - - $AC3header['bsi'] = getid3_lib::BigEndian2Bin(fread($fd, 15)); - $ac3_bsi_offset = 0; - - $thisfile_ac3_raw_bsi['bsid'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 5)); - $ac3_bsi_offset += 5; - if ($thisfile_ac3_raw_bsi['bsid'] > 8) { - // Decoders which can decode version 8 will thus be able to decode version numbers less than 8. - // If this standard is extended by the addition of additional elements or features, a value of bsid greater than 8 will be used. - // Decoders built to this version of the standard will not be able to decode versions with bsid greater than 8. - $ThisFileInfo['error'][] = 'Bit stream identification is version '.$thisfile_ac3_raw_bsi['bsid'].', but getID3() only understands up to version 8'; - unset($thisfile_ac3); - return false; - } - - $thisfile_ac3_raw_bsi['bsmod'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 3)); - $ac3_bsi_offset += 3; - $thisfile_ac3_raw_bsi['acmod'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 3)); - $ac3_bsi_offset += 3; - - $thisfile_ac3['service_type'] = $this->AC3serviceTypeLookup($thisfile_ac3_raw_bsi['bsmod'], $thisfile_ac3_raw_bsi['acmod']); - $ac3_coding_mode = $this->AC3audioCodingModeLookup($thisfile_ac3_raw_bsi['acmod']); - foreach($ac3_coding_mode as $key => $value) { - $thisfile_ac3[$key] = $value; - } - switch ($thisfile_ac3_raw_bsi['acmod']) { - case 0: - case 1: - $ThisFileInfo['audio']['channelmode'] = 'mono'; - break; - case 3: - case 4: - $ThisFileInfo['audio']['channelmode'] = 'stereo'; - break; - default: - $ThisFileInfo['audio']['channelmode'] = 'surround'; - break; - } - $ThisFileInfo['audio']['channels'] = $thisfile_ac3['num_channels']; - - if ($thisfile_ac3_raw_bsi['acmod'] & 0x01) { - // If the lsb of acmod is a 1, center channel is in use and cmixlev follows in the bit stream. - $thisfile_ac3_raw_bsi['cmixlev'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 2)); - $ac3_bsi_offset += 2; - $thisfile_ac3['center_mix_level'] = $this->AC3centerMixLevelLookup($thisfile_ac3_raw_bsi['cmixlev']); - } - - if ($thisfile_ac3_raw_bsi['acmod'] & 0x04) { - // If the msb of acmod is a 1, surround channels are in use and surmixlev follows in the bit stream. - $thisfile_ac3_raw_bsi['surmixlev'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 2)); - $ac3_bsi_offset += 2; - $thisfile_ac3['surround_mix_level'] = $this->AC3surroundMixLevelLookup($thisfile_ac3_raw_bsi['surmixlev']); - } - - if ($thisfile_ac3_raw_bsi['acmod'] == 0x02) { - // When operating in the two channel mode, this 2-bit code indicates whether or not the program has been encoded in Dolby Surround. - $thisfile_ac3_raw_bsi['dsurmod'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 2)); - $ac3_bsi_offset += 2; - $thisfile_ac3['dolby_surround_mode'] = $this->AC3dolbySurroundModeLookup($thisfile_ac3_raw_bsi['dsurmod']); - } - - $thisfile_ac3_raw_bsi['lfeon'] = (bool) bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 1)); - $ac3_bsi_offset += 1; - $thisfile_ac3['lfe_enabled'] = $thisfile_ac3_raw_bsi['lfeon']; - if ($thisfile_ac3_raw_bsi['lfeon']) { - //$ThisFileInfo['audio']['channels']++; - $ThisFileInfo['audio']['channels'] .= '.1'; - } - - $thisfile_ac3['channels_enabled'] = $this->AC3channelsEnabledLookup($thisfile_ac3_raw_bsi['acmod'], $thisfile_ac3_raw_bsi['lfeon']); - - // This indicates how far the average dialogue level is below digital 100 percent. Valid values are 1–31. - // The value of 0 is reserved. The values of 1 to 31 are interpreted as -1 dB to -31 dB with respect to digital 100 percent. - $thisfile_ac3_raw_bsi['dialnorm'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 5)); - $ac3_bsi_offset += 5; - $thisfile_ac3['dialogue_normalization'] = '-'.$thisfile_ac3_raw_bsi['dialnorm'].'dB'; - - $thisfile_ac3_raw_bsi['compre_flag'] = (bool) bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 1)); - $ac3_bsi_offset += 1; - if ($thisfile_ac3_raw_bsi['compre_flag']) { - $thisfile_ac3_raw_bsi['compr'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 8)); - $ac3_bsi_offset += 8; - $thisfile_ac3['heavy_compression'] = $this->AC3heavyCompression($thisfile_ac3_raw_bsi['compr']); - } - - $thisfile_ac3_raw_bsi['langcode_flag'] = (bool) bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 1)); - $ac3_bsi_offset += 1; - if ($thisfile_ac3_raw_bsi['langcode_flag']) { - $thisfile_ac3_raw_bsi['langcod'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 8)); - $ac3_bsi_offset += 8; - } - - $thisfile_ac3_raw_bsi['audprodie'] = (bool) bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 1)); - $ac3_bsi_offset += 1; - if ($thisfile_ac3_raw_bsi['audprodie']) { - $thisfile_ac3_raw_bsi['mixlevel'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 5)); - $ac3_bsi_offset += 5; - $thisfile_ac3_raw_bsi['roomtyp'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 2)); - $ac3_bsi_offset += 2; - - $thisfile_ac3['mixing_level'] = (80 + $thisfile_ac3_raw_bsi['mixlevel']).'dB'; - $thisfile_ac3['room_type'] = $this->AC3roomTypeLookup($thisfile_ac3_raw_bsi['roomtyp']); - } - - if ($thisfile_ac3_raw_bsi['acmod'] == 0x00) { - // If acmod is 0, then two completely independent program channels (dual mono) - // are encoded into the bit stream, and are referenced as Ch1, Ch2. In this case, - // a number of additional items are present in BSI or audblk to fully describe Ch2. - - - // This indicates how far the average dialogue level is below digital 100 percent. Valid values are 1–31. - // The value of 0 is reserved. The values of 1 to 31 are interpreted as -1 dB to -31 dB with respect to digital 100 percent. - $thisfile_ac3_raw_bsi['dialnorm2'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 5)); - $ac3_bsi_offset += 5; - $thisfile_ac3['dialogue_normalization2'] = '-'.$thisfile_ac3_raw_bsi['dialnorm2'].'dB'; - - $thisfile_ac3_raw_bsi['compre_flag2'] = (bool) bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 1)); - $ac3_bsi_offset += 1; - if ($thisfile_ac3_raw_bsi['compre_flag2']) { - $thisfile_ac3_raw_bsi['compr2'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 8)); - $ac3_bsi_offset += 8; - $thisfile_ac3['heavy_compression2'] = $this->AC3heavyCompression($thisfile_ac3_raw_bsi['compr2']); - } - - $thisfile_ac3_raw_bsi['langcode_flag2'] = (bool) bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 1)); - $ac3_bsi_offset += 1; - if ($thisfile_ac3_raw_bsi['langcode_flag2']) { - $thisfile_ac3_raw_bsi['langcod2'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 8)); - $ac3_bsi_offset += 8; - } - - $thisfile_ac3_raw_bsi['audprodie2'] = (bool) bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 1)); - $ac3_bsi_offset += 1; - if ($thisfile_ac3_raw_bsi['audprodie2']) { - $thisfile_ac3_raw_bsi['mixlevel2'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 5)); - $ac3_bsi_offset += 5; - $thisfile_ac3_raw_bsi['roomtyp2'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 2)); - $ac3_bsi_offset += 2; - - $thisfile_ac3['mixing_level2'] = (80 + $thisfile_ac3_raw_bsi['mixlevel2']).'dB'; - $thisfile_ac3['room_type2'] = $this->AC3roomTypeLookup($thisfile_ac3_raw_bsi['roomtyp2']); - } - - } - - $thisfile_ac3_raw_bsi['copyright'] = (bool) bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 1)); - $ac3_bsi_offset += 1; - - $thisfile_ac3_raw_bsi['original'] = (bool) bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 1)); - $ac3_bsi_offset += 1; - - $thisfile_ac3_raw_bsi['timecode1_flag'] = (bool) bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 1)); - $ac3_bsi_offset += 1; - if ($thisfile_ac3_raw_bsi['timecode1_flag']) { - $thisfile_ac3_raw_bsi['timecode1'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 14)); - $ac3_bsi_offset += 14; - } - - $thisfile_ac3_raw_bsi['timecode2_flag'] = (bool) bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 1)); - $ac3_bsi_offset += 1; - if ($thisfile_ac3_raw_bsi['timecode2_flag']) { - $thisfile_ac3_raw_bsi['timecode2'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 14)); - $ac3_bsi_offset += 14; - } - - $thisfile_ac3_raw_bsi['addbsi_flag'] = (bool) bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 1)); - $ac3_bsi_offset += 1; - if ($thisfile_ac3_raw_bsi['addbsi_flag']) { - $thisfile_ac3_raw_bsi['addbsi_length'] = bindec(substr($AC3header['bsi'], $ac3_bsi_offset, 6)); - $ac3_bsi_offset += 6; - - $AC3header['bsi'] .= getid3_lib::BigEndian2Bin(fread($fd, $thisfile_ac3_raw_bsi['addbsi_length'])); - - $thisfile_ac3_raw_bsi['addbsi_data'] = substr($AC3header['bsi'], $ac3_bsi_offset, $thisfile_ac3_raw_bsi['addbsi_length'] * 8); - $ac3_bsi_offset += $thisfile_ac3_raw_bsi['addbsi_length'] * 8; - } - - } - - return true; - } - - - function AC3sampleRateCodeLookup($fscod) { - static $AC3sampleRateCodeLookup = array( - 0 => 48000, - 1 => 44100, - 2 => 32000, - 3 => 'reserved' // If the reserved code is indicated, the decoder should not attempt to decode audio and should mute. - ); - return (isset($AC3sampleRateCodeLookup[$fscod]) ? $AC3sampleRateCodeLookup[$fscod] : false); - } - - function AC3serviceTypeLookup($bsmod, $acmod) { - static $AC3serviceTypeLookup = array(); - if (empty($AC3serviceTypeLookup)) { - for ($i = 0; $i <= 7; $i++) { - $AC3serviceTypeLookup[0][$i] = 'main audio service: complete main (CM)'; - $AC3serviceTypeLookup[1][$i] = 'main audio service: music and effects (ME)'; - $AC3serviceTypeLookup[2][$i] = 'associated service: visually impaired (VI)'; - $AC3serviceTypeLookup[3][$i] = 'associated service: hearing impaired (HI)'; - $AC3serviceTypeLookup[4][$i] = 'associated service: dialogue (D)'; - $AC3serviceTypeLookup[5][$i] = 'associated service: commentary (C)'; - $AC3serviceTypeLookup[6][$i] = 'associated service: emergency (E)'; - } - - $AC3serviceTypeLookup[7][1] = 'associated service: voice over (VO)'; - for ($i = 2; $i <= 7; $i++) { - $AC3serviceTypeLookup[7][$i] = 'main audio service: karaoke'; - } - } - return (isset($AC3serviceTypeLookup[$bsmod][$acmod]) ? $AC3serviceTypeLookup[$bsmod][$acmod] : false); - } - - function AC3audioCodingModeLookup($acmod) { - static $AC3audioCodingModeLookup = array(); - if (empty($AC3audioCodingModeLookup)) { - // array(channel configuration, # channels (not incl LFE), channel order) - $AC3audioCodingModeLookup = array ( - 0 => array('channel_config'=>'1+1', 'num_channels'=>2, 'channel_order'=>'Ch1,Ch2'), - 1 => array('channel_config'=>'1/0', 'num_channels'=>1, 'channel_order'=>'C'), - 2 => array('channel_config'=>'2/0', 'num_channels'=>2, 'channel_order'=>'L,R'), - 3 => array('channel_config'=>'3/0', 'num_channels'=>3, 'channel_order'=>'L,C,R'), - 4 => array('channel_config'=>'2/1', 'num_channels'=>3, 'channel_order'=>'L,R,S'), - 5 => array('channel_config'=>'3/1', 'num_channels'=>4, 'channel_order'=>'L,C,R,S'), - 6 => array('channel_config'=>'2/2', 'num_channels'=>4, 'channel_order'=>'L,R,SL,SR'), - 7 => array('channel_config'=>'3/2', 'num_channels'=>5, 'channel_order'=>'L,C,R,SL,SR') - ); - } - return (isset($AC3audioCodingModeLookup[$acmod]) ? $AC3audioCodingModeLookup[$acmod] : false); - } - - function AC3centerMixLevelLookup($cmixlev) { - static $AC3centerMixLevelLookup; - if (empty($AC3centerMixLevelLookup)) { - $AC3centerMixLevelLookup = array( - 0 => pow(2, -3.0 / 6), // 0.707 (–3.0 dB) - 1 => pow(2, -4.5 / 6), // 0.595 (–4.5 dB) - 2 => pow(2, -6.0 / 6), // 0.500 (–6.0 dB) - 3 => 'reserved' - ); - } - return (isset($AC3centerMixLevelLookup[$cmixlev]) ? $AC3centerMixLevelLookup[$cmixlev] : false); - } - - function AC3surroundMixLevelLookup($surmixlev) { - static $AC3surroundMixLevelLookup; - if (empty($AC3surroundMixLevelLookup)) { - $AC3surroundMixLevelLookup = array( - 0 => pow(2, -3.0 / 6), - 1 => pow(2, -6.0 / 6), - 2 => 0, - 3 => 'reserved' - ); - } - return (isset($AC3surroundMixLevelLookup[$surmixlev]) ? $AC3surroundMixLevelLookup[$surmixlev] : false); - } - - function AC3dolbySurroundModeLookup($dsurmod) { - static $AC3dolbySurroundModeLookup = array( - 0 => 'not indicated', - 1 => 'Not Dolby Surround encoded', - 2 => 'Dolby Surround encoded', - 3 => 'reserved' - ); - return (isset($AC3dolbySurroundModeLookup[$dsurmod]) ? $AC3dolbySurroundModeLookup[$dsurmod] : false); - } - - function AC3channelsEnabledLookup($acmod, $lfeon) { - $AC3channelsEnabledLookup = array( - 'ch1'=>(bool) ($acmod == 0), - 'ch2'=>(bool) ($acmod == 0), - 'left'=>(bool) ($acmod > 1), - 'right'=>(bool) ($acmod > 1), - 'center'=>(bool) ($acmod & 0x01), - 'surround_mono'=>false, - 'surround_left'=>false, - 'surround_right'=>false, - 'lfe'=>$lfeon); - switch ($acmod) { - case 4: - case 5: - $AC3channelsEnabledLookup['surround_mono'] = true; - break; - case 6: - case 7: - $AC3channelsEnabledLookup['surround_left'] = true; - $AC3channelsEnabledLookup['surround_right'] = true; - break; - } - return $AC3channelsEnabledLookup; - } - - function AC3heavyCompression($compre) { - // The first four bits indicate gain changes in 6.02dB increments which can be - // implemented with an arithmetic shift operation. The following four bits - // indicate linear gain changes, and require a 5-bit multiply. - // We will represent the two 4-bit fields of compr as follows: - // X0 X1 X2 X3 . Y4 Y5 Y6 Y7 - // The meaning of the X values is most simply described by considering X to represent a 4-bit - // signed integer with values from –8 to +7. The gain indicated by X is then (X + 1) * 6.02 dB. The - // following table shows this in detail. - - // Meaning of 4 msb of compr - // 7 +48.16 dB - // 6 +42.14 dB - // 5 +36.12 dB - // 4 +30.10 dB - // 3 +24.08 dB - // 2 +18.06 dB - // 1 +12.04 dB - // 0 +6.02 dB - // -1 0 dB - // -2 –6.02 dB - // -3 –12.04 dB - // -4 –18.06 dB - // -5 –24.08 dB - // -6 –30.10 dB - // -7 –36.12 dB - // -8 –42.14 dB - - $fourbit = str_pad(decbin(($compre & 0xF0) >> 4), 4, '0', STR_PAD_LEFT); - if ($fourbit{0} == '1') { - $log_gain = -8 + bindec(substr($fourbit, 1)); - } else { - $log_gain = bindec(substr($fourbit, 1)); - } - $log_gain = ($log_gain + 1) * getid3_lib::RGADamplitude2dB(2); - - // The value of Y is a linear representation of a gain change of up to –6 dB. Y is considered to - // be an unsigned fractional integer, with a leading value of 1, or: 0.1 Y4 Y5 Y6 Y7 (base 2). Y can - // represent values between 0.111112 (or 31/32) and 0.100002 (or 1/2). Thus, Y can represent gain - // changes from –0.28 dB to –6.02 dB. - - $lin_gain = (16 + ($compre & 0x0F)) / 32; - - // The combination of X and Y values allows compr to indicate gain changes from - // 48.16 – 0.28 = +47.89 dB, to - // –42.14 – 6.02 = –48.16 dB. - - return $log_gain - $lin_gain; - } - - function AC3roomTypeLookup($roomtyp) { - static $AC3roomTypeLookup = array( - 0 => 'not indicated', - 1 => 'large room, X curve monitor', - 2 => 'small room, flat monitor', - 3 => 'reserved' - ); - return (isset($AC3roomTypeLookup[$roomtyp]) ? $AC3roomTypeLookup[$roomtyp] : false); - } - - function AC3frameSizeLookup($frmsizecod, $fscod) { - $padding = (bool) ($frmsizecod % 2); - $framesizeid = floor($frmsizecod / 2); - - static $AC3frameSizeLookup = array(); - if (empty($AC3frameSizeLookup)) { - $AC3frameSizeLookup = array ( - 0 => array(128, 138, 192), - 1 => array(40, 160, 174, 240), - 2 => array(48, 192, 208, 288), - 3 => array(56, 224, 242, 336), - 4 => array(64, 256, 278, 384), - 5 => array(80, 320, 348, 480), - 6 => array(96, 384, 416, 576), - 7 => array(112, 448, 486, 672), - 8 => array(128, 512, 556, 768), - 9 => array(160, 640, 696, 960), - 10 => array(192, 768, 834, 1152), - 11 => array(224, 896, 974, 1344), - 12 => array(256, 1024, 1114, 1536), - 13 => array(320, 1280, 1392, 1920), - 14 => array(384, 1536, 1670, 2304), - 15 => array(448, 1792, 1950, 2688), - 16 => array(512, 2048, 2228, 3072), - 17 => array(576, 2304, 2506, 3456), - 18 => array(640, 2560, 2786, 3840) - ); - } - if (($fscod == 1) && $padding) { - // frame lengths are padded by 1 word (16 bits) at 44100 - $AC3frameSizeLookup[$frmsizecod] += 2; - } - return (isset($AC3frameSizeLookup[$framesizeid][$fscod]) ? $AC3frameSizeLookup[$framesizeid][$fscod] : false); - } - - function AC3bitrateLookup($frmsizecod) { - $framesizeid = floor($frmsizecod / 2); - - static $AC3bitrateLookup = array( - 0 => 32000, - 1 => 40000, - 2 => 48000, - 3 => 56000, - 4 => 64000, - 5 => 80000, - 6 => 96000, - 7 => 112000, - 8 => 128000, - 9 => 160000, - 10 => 192000, - 11 => 224000, - 12 => 256000, - 13 => 320000, - 14 => 384000, - 15 => 448000, - 16 => 512000, - 17 => 576000, - 18 => 640000 - ); - return (isset($AC3bitrateLookup[$framesizeid]) ? $AC3bitrateLookup[$framesizeid] : false); - } - - -} - -?>
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