| <Website> | getID3 |  |
|
| Size: | 13085 |
| Storage flags: | strip |
<?php
class getid3_ac3 extends getid3_handler
{
private $AC3header = array();
private $BSIoffset = 0;
const syncword = "\x0B\x77";
public function Analyze() {
$info = &$this->getid3->info;
$info['ac3']['raw']['bsi'] = array();
$thisfile_ac3 = &$info['ac3'];
$thisfile_ac3_raw = &$thisfile_ac3['raw'];
$thisfile_ac3_raw_bsi = &$thisfile_ac3_raw['bsi'];
$info['fileformat'] = 'ac3';
$this->fseek($info['avdataoffset']);
$this->AC3header['syncinfo'] = $this->fread(5);
if (strpos($this->AC3header['syncinfo'], self::syncword) === 0) {
$thisfile_ac3_raw['synchinfo']['synchword'] = self::syncword;
$offset = 2;
} else {
if (!$this->isDependencyFor('matroska')) {
unset($info['fileformat'], $info['ac3']);
return $this->error('Expecting "'.getid3_lib::PrintHexBytes(self::syncword).'" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes(substr($this->AC3header['syncinfo'], 0, 2)).'"');
}
$offset = 0;
$this->fseek(-2, SEEK_CUR);
}
$info['audio']['dataformat'] = 'ac3';
$info['audio']['bitrate_mode'] = 'cbr';
$info['audio']['lossless'] = false;
$thisfile_ac3_raw['synchinfo']['crc1'] = getid3_lib::LittleEndian2Int(substr($this->AC3header['syncinfo'], $offset, 2));
$ac3_synchinfo_fscod_frmsizecod = getid3_lib::LittleEndian2Int(substr($this->AC3header['syncinfo'], ($offset + 2), 1));
$thisfile_ac3_raw['synchinfo']['fscod'] = ($ac3_synchinfo_fscod_frmsizecod & 0xC0) >> 6;
$thisfile_ac3_raw['synchinfo']['frmsizecod'] = ($ac3_synchinfo_fscod_frmsizecod & 0x3F);
$thisfile_ac3['sample_rate'] = self::sampleRateCodeLookup($thisfile_ac3_raw['synchinfo']['fscod']);
if ($thisfile_ac3_raw['synchinfo']['fscod'] <= 3) {
$info['audio']['sample_rate'] = $thisfile_ac3['sample_rate'];
}
$thisfile_ac3['frame_length'] = self::frameSizeLookup($thisfile_ac3_raw['synchinfo']['frmsizecod'], $thisfile_ac3_raw['synchinfo']['fscod']);
$thisfile_ac3['bitrate'] = self::bitrateLookup($thisfile_ac3_raw['synchinfo']['frmsizecod']);
$info['audio']['bitrate'] = $thisfile_ac3['bitrate'];
$this->AC3header['bsi'] = getid3_lib::BigEndian2Bin($this->fread(15));
$ac3_bsi_offset = 0;
$thisfile_ac3_raw_bsi['bsid'] = $this->readHeaderBSI(5);
if ($thisfile_ac3_raw_bsi['bsid'] > 8) {
$this->error('Bit stream identification is version '.$thisfile_ac3_raw_bsi['bsid'].', but getID3() only understands up to version 8');
unset($info['ac3']);
return false;
}
$thisfile_ac3_raw_bsi['bsmod'] = $this->readHeaderBSI(3);
$thisfile_ac3_raw_bsi['acmod'] = $this->readHeaderBSI(3);
$thisfile_ac3['service_type'] = self::serviceTypeLookup($thisfile_ac3_raw_bsi['bsmod'], $thisfile_ac3_raw_bsi['acmod']);
$ac3_coding_mode = self::audioCodingModeLookup($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:
$info['audio']['channelmode'] = 'mono';
break;
case 3:
case 4:
$info['audio']['channelmode'] = 'stereo';
break;
default:
$info['audio']['channelmode'] = 'surround';
break;
}
$info['audio']['channels'] = $thisfile_ac3['num_channels'];
if ($thisfile_ac3_raw_bsi['acmod'] & 0x01) {
$thisfile_ac3_raw_bsi['cmixlev'] = $this->readHeaderBSI(2);
$thisfile_ac3['center_mix_level'] = self::centerMixLevelLookup($thisfile_ac3_raw_bsi['cmixlev']);
}
if ($thisfile_ac3_raw_bsi['acmod'] & 0x04) {
$thisfile_ac3_raw_bsi['surmixlev'] = $this->readHeaderBSI(2);
$thisfile_ac3['surround_mix_level'] = self::surroundMixLevelLookup($thisfile_ac3_raw_bsi['surmixlev']);
}
if ($thisfile_ac3_raw_bsi['acmod'] == 0x02) {
$thisfile_ac3_raw_bsi['dsurmod'] = $this->readHeaderBSI(2);
$thisfile_ac3['dolby_surround_mode'] = self::dolbySurroundModeLookup($thisfile_ac3_raw_bsi['dsurmod']);
}
$thisfile_ac3_raw_bsi['lfeon'] = (bool) $this->readHeaderBSI(1);
$thisfile_ac3['lfe_enabled'] = $thisfile_ac3_raw_bsi['lfeon'];
if ($thisfile_ac3_raw_bsi['lfeon']) {
$info['audio']['channels'] .= '.1';
}
$thisfile_ac3['channels_enabled'] = self::channelsEnabledLookup($thisfile_ac3_raw_bsi['acmod'], $thisfile_ac3_raw_bsi['lfeon']);
$thisfile_ac3_raw_bsi['dialnorm'] = $this->readHeaderBSI(5);
$thisfile_ac3['dialogue_normalization'] = '-'.$thisfile_ac3_raw_bsi['dialnorm'].'dB';
$thisfile_ac3_raw_bsi['compre_flag'] = (bool) $this->readHeaderBSI(1);
if ($thisfile_ac3_raw_bsi['compre_flag']) {
$thisfile_ac3_raw_bsi['compr'] = $this->readHeaderBSI(8);
$thisfile_ac3['heavy_compression'] = self::heavyCompression($thisfile_ac3_raw_bsi['compr']);
}
$thisfile_ac3_raw_bsi['langcode_flag'] = (bool) $this->readHeaderBSI(1);
if ($thisfile_ac3_raw_bsi['langcode_flag']) {
$thisfile_ac3_raw_bsi['langcod'] = $this->readHeaderBSI(8);
}
$thisfile_ac3_raw_bsi['audprodie'] = (bool) $this->readHeaderBSI(1);
if ($thisfile_ac3_raw_bsi['audprodie']) {
$thisfile_ac3_raw_bsi['mixlevel'] = $this->readHeaderBSI(5);
$thisfile_ac3_raw_bsi['roomtyp'] = $this->readHeaderBSI(2);
$thisfile_ac3['mixing_level'] = (80 + $thisfile_ac3_raw_bsi['mixlevel']).'dB';
$thisfile_ac3['room_type'] = self::roomTypeLookup($thisfile_ac3_raw_bsi['roomtyp']);
}
if ($thisfile_ac3_raw_bsi['acmod'] == 0x00) {
$thisfile_ac3_raw_bsi['dialnorm2'] = $this->readHeaderBSI(5);
$thisfile_ac3['dialogue_normalization2'] = '-'.$thisfile_ac3_raw_bsi['dialnorm2'].'dB';
$thisfile_ac3_raw_bsi['compre_flag2'] = (bool) $this->readHeaderBSI(1);
if ($thisfile_ac3_raw_bsi['compre_flag2']) {
$thisfile_ac3_raw_bsi['compr2'] = $this->readHeaderBSI(8);
$thisfile_ac3['heavy_compression2'] = self::heavyCompression($thisfile_ac3_raw_bsi['compr2']);
}
$thisfile_ac3_raw_bsi['langcode_flag2'] = (bool) $this->readHeaderBSI(1);
if ($thisfile_ac3_raw_bsi['langcode_flag2']) {
$thisfile_ac3_raw_bsi['langcod2'] = $this->readHeaderBSI(8);
}
$thisfile_ac3_raw_bsi['audprodie2'] = (bool) $this->readHeaderBSI(1);
if ($thisfile_ac3_raw_bsi['audprodie2']) {
$thisfile_ac3_raw_bsi['mixlevel2'] = $this->readHeaderBSI(5);
$thisfile_ac3_raw_bsi['roomtyp2'] = $this->readHeaderBSI(2);
$thisfile_ac3['mixing_level2'] = (80 + $thisfile_ac3_raw_bsi['mixlevel2']).'dB';
$thisfile_ac3['room_type2'] = self::roomTypeLookup($thisfile_ac3_raw_bsi['roomtyp2']);
}
}
$thisfile_ac3_raw_bsi['copyright'] = (bool) $this->readHeaderBSI(1);
$thisfile_ac3_raw_bsi['original'] = (bool) $this->readHeaderBSI(1);
$thisfile_ac3_raw_bsi['timecode1_flag'] = (bool) $this->readHeaderBSI(1);
if ($thisfile_ac3_raw_bsi['timecode1_flag']) {
$thisfile_ac3_raw_bsi['timecode1'] = $this->readHeaderBSI(14);
}
$thisfile_ac3_raw_bsi['timecode2_flag'] = (bool) $this->readHeaderBSI(1);
if ($thisfile_ac3_raw_bsi['timecode2_flag']) {
$thisfile_ac3_raw_bsi['timecode2'] = $this->readHeaderBSI(14);
}
$thisfile_ac3_raw_bsi['addbsi_flag'] = (bool) $this->readHeaderBSI(1);
if ($thisfile_ac3_raw_bsi['addbsi_flag']) {
$thisfile_ac3_raw_bsi['addbsi_length'] = $this->readHeaderBSI(6);
$this->AC3header['bsi'] .= getid3_lib::BigEndian2Bin($this->fread($thisfile_ac3_raw_bsi['addbsi_length']));
$thisfile_ac3_raw_bsi['addbsi_data'] = substr($this->AC3header['bsi'], $this->BSIoffset, $thisfile_ac3_raw_bsi['addbsi_length'] * 8);
$this->BSIoffset += $thisfile_ac3_raw_bsi['addbsi_length'] * 8;
}
return true;
}
private function readHeaderBSI($length) {
$data = substr($this->AC3header['bsi'], $this->BSIoffset, $length);
$this->BSIoffset += $length;
return bindec($data);
}
public static function sampleRateCodeLookup($fscod) {
static $sampleRateCodeLookup = array(
0 => 48000,
1 => 44100,
2 => 32000,
3 => 'reserved'
);
return (isset($sampleRateCodeLookup[$fscod]) ? $sampleRateCodeLookup[$fscod] : false);
}
public static function serviceTypeLookup($bsmod, $acmod) {
static $serviceTypeLookup = array();
if (empty($serviceTypeLookup)) {
for ($i = 0; $i <= 7; $i++) {
$serviceTypeLookup[0][$i] = 'main audio service: complete main (CM)';
$serviceTypeLookup[1][$i] = 'main audio service: music and effects (ME)';
$serviceTypeLookup[2][$i] = 'associated service: visually impaired (VI)';
$serviceTypeLookup[3][$i] = 'associated service: hearing impaired (HI)';
$serviceTypeLookup[4][$i] = 'associated service: dialogue (D)';
$serviceTypeLookup[5][$i] = 'associated service: commentary (C)';
$serviceTypeLookup[6][$i] = 'associated service: emergency (E)';
}
$serviceTypeLookup[7][1] = 'associated service: voice over (VO)';
for ($i = 2; $i <= 7; $i++) {
$serviceTypeLookup[7][$i] = 'main audio service: karaoke';
}
}
return (isset($serviceTypeLookup[$bsmod][$acmod]) ? $serviceTypeLookup[$bsmod][$acmod] : false);
}
public static function audioCodingModeLookup($acmod) {
static $audioCodingModeLookup = array (
0 => array('channel_config'=>'1+1', 'num_channels'=>2, 'channel_order'=>'Ch1,Ch2'),
1 => array('channel_config'=>'1/0', 'num_channels'=>1, 'channel_order'=>'C'),
2 => array('channel_config'=>'2/0', 'num_channels'=>2, 'channel_order'=>'L,R'),
3 => array('channel_config'=>'3/0', 'num_channels'=>3, 'channel_order'=>'L,C,R'),
4 => array('channel_config'=>'2/1', 'num_channels'=>3, 'channel_order'=>'L,R,S'),
5 => array('channel_config'=>'3/1', 'num_channels'=>4, 'channel_order'=>'L,C,R,S'),
6 => array('channel_config'=>'2/2', 'num_channels'=>4, 'channel_order'=>'L,R,SL,SR'),
7 => array('channel_config'=>'3/2', 'num_channels'=>5, 'channel_order'=>'L,C,R,SL,SR'),
);
return (isset($audioCodingModeLookup[$acmod]) ? $audioCodingModeLookup[$acmod] : false);
}
public static function centerMixLevelLookup($cmixlev) {
static $centerMixLevelLookup;
if (empty($centerMixLevelLookup)) {
$centerMixLevelLookup = array(
0 => pow(2, -3.0 / 6),
1 => pow(2, -4.5 / 6),
2 => pow(2, -6.0 / 6),
3 => 'reserved'
);
}
return (isset($centerMixLevelLookup[$cmixlev]) ? $centerMixLevelLookup[$cmixlev] : false);
}
public static function surroundMixLevelLookup($surmixlev) {
static $surroundMixLevelLookup;
if (empty($surroundMixLevelLookup)) {
$surroundMixLevelLookup = array(
0 => pow(2, -3.0 / 6),
1 => pow(2, -6.0 / 6),
2 => 0,
3 => 'reserved'
);
}
return (isset($surroundMixLevelLookup[$surmixlev]) ? $surroundMixLevelLookup[$surmixlev] : false);
}
public static function dolbySurroundModeLookup($dsurmod) {
static $dolbySurroundModeLookup = array(
0 => 'not indicated',
1 => 'Not Dolby Surround encoded',
2 => 'Dolby Surround encoded',
3 => 'reserved'
);
return (isset($dolbySurroundModeLookup[$dsurmod]) ? $dolbySurroundModeLookup[$dsurmod] : false);
}
public static function channelsEnabledLookup($acmod, $lfeon) {
$lookup = array(
'ch1'=>(bool) ($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:
$lookup['surround_mono'] = true;
break;
case 6:
case 7:
$lookup['surround_left'] = true;
$lookup['surround_right'] = true;
break;
}
return $lookup;
}
public static function heavyCompression($compre) {
$fourbit = str_pad(decbin(($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);
$lin_gain = (16 + ($compre & 0x0F)) / 32;
return $log_gain - $lin_gain;
}
public static function roomTypeLookup($roomtyp) {
static $roomTypeLookup = array(
0 => 'not indicated',
1 => 'large room, X curve monitor',
2 => 'small room, flat monitor',
3 => 'reserved'
);
return (isset($roomTypeLookup[$roomtyp]) ? $roomTypeLookup[$roomtyp] : false);
}
public static function frameSizeLookup($frmsizecod, $fscod) {
$padding = (bool) ($frmsizecod % 2);
$framesizeid = floor($frmsizecod / 2);
static $frameSizeLookup = array();
if (empty($frameSizeLookup)) {
$frameSizeLookup = array (
0 => array(128, 138, 192),
1 => array(40, 160, 174, 240),
2 => array(48, 192, 208, 288),
3 => array(56, 224, 242, 336),
4 => array(64, 256, 278, 384),
5 => array(80, 320, 348, 480),
6 => array(96, 384, 416, 576),
7 => array(112, 448, 486, 672),
8 => array(128, 512, 556, 768),
9 => array(160, 640, 696, 960),
10 => array(192, 768, 834, 1152),
11 => array(224, 896, 974, 1344),
12 => array(256, 1024, 1114, 1536),
13 => array(320, 1280, 1392, 1920),
14 => array(384, 1536, 1670, 2304),
15 => array(448, 1792, 1950, 2688),
16 => array(512, 2048, 2228, 3072),
17 => array(576, 2304, 2506, 3456),
18 => array(640, 2560, 2786, 3840)
);
}
if (($fscod == 1) && $padding) {
$frameSizeLookup[$frmsizecod] += 2;
}
return (isset($frameSizeLookup[$framesizeid][$fscod]) ? $frameSizeLookup[$framesizeid][$fscod] : false);
}
public static function bitrateLookup($frmsizecod) {
$framesizeid = floor($frmsizecod / 2);
static $bitrateLookup = array(
0 => 32000,
1 => 40000,
2 => 48000,
3 => 56000,
4 => 64000,
5 => 80000,
6 => 96000,
7 => 112000,
8 => 128000,
9 => 160000,
10 => 192000,
11 => 224000,
12 => 256000,
13 => 320000,
14 => 384000,
15 => 448000,
16 => 512000,
17 => 576000,
18 => 640000
);
return (isset($bitrateLookup[$framesizeid]) ? $bitrateLookup[$framesizeid] : false);
}
}