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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.mpc.php //
// module for analyzing Musepack/MPEG+ Audio files //
// dependencies: NONE //
// ///
/////////////////////////////////////////////////////////////////
class getid3_mpc
{
function getid3_mpc(&$fd, &$ThisFileInfo) {
// http://www.uni-jena.de/~pfk/mpp/sv8/header.html
$ThisFileInfo['mpc']['header'] = array();
$thisfile_mpc_header = &$ThisFileInfo['mpc']['header'];
$ThisFileInfo['fileformat'] = 'mpc';
$ThisFileInfo['audio']['dataformat'] = 'mpc';
$ThisFileInfo['audio']['bitrate_mode'] = 'vbr';
$ThisFileInfo['audio']['channels'] = 2; // the format appears to be hardcoded for stereo only
$ThisFileInfo['audio']['lossless'] = false;
fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);
$thisfile_mpc_header['size'] = 28;
$MPCheaderData = fread($fd, $thisfile_mpc_header['size']);
$offset = 0;
if (substr($MPCheaderData, $offset, 3) == 'MP+') {
// great, this is SV7+
$thisfile_mpc_header['raw']['preamble'] = substr($MPCheaderData, $offset, 3); // should be 'MP+'
$offset += 3;
} elseif (preg_match('/^[\x00\x01\x10\x11\x40\x41\x50\x51\x80\x81\x90\x91\xC0\xC1\xD0\xD1][\x20-37][\x00\x20\x40\x60\x80\xA0\xC0\xE0]/s', substr($MPCheaderData, 0, 4))) {
// this is SV4 - SV6, handle seperately
$thisfile_mpc_header['size'] = 8;
// add size of file header to avdataoffset - calc bitrate correctly + MD5 data
$ThisFileInfo['avdataoffset'] += $thisfile_mpc_header['size'];
// Most of this code adapted from Jurgen Faul's MPEGplus source code - thanks Jurgen! :)
$HeaderDWORD[0] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, 0, 4));
$HeaderDWORD[1] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, 4, 4));
// DDDD DDDD CCCC CCCC BBBB BBBB AAAA AAAA
// aaaa aaaa abcd dddd dddd deee eeff ffff
//
// a = bitrate = anything
// b = IS = anything
// c = MS = anything
// d = streamversion = 0000000004 or 0000000005 or 0000000006
// e = maxband = anything
// f = blocksize = 000001 for SV5+, anything(?) for SV4
$thisfile_mpc_header['target_bitrate'] = (($HeaderDWORD[0] & 0xFF800000) >> 23);
$thisfile_mpc_header['intensity_stereo'] = (bool) (($HeaderDWORD[0] & 0x00400000) >> 22);
$thisfile_mpc_header['mid-side_stereo'] = (bool) (($HeaderDWORD[0] & 0x00200000) >> 21);
$thisfile_mpc_header['stream_major_version'] = ($HeaderDWORD[0] & 0x001FF800) >> 11;
$thisfile_mpc_header['stream_minor_version'] = 0; // no sub-version numbers before SV7
$thisfile_mpc_header['max_band'] = ($HeaderDWORD[0] & 0x000007C0) >> 6; // related to lowpass frequency, not sure how it translates exactly
$thisfile_mpc_header['block_size'] = ($HeaderDWORD[0] & 0x0000003F);
switch ($thisfile_mpc_header['stream_major_version']) {
case 4:
$thisfile_mpc_header['frame_count'] = ($HeaderDWORD[1] >> 16);
break;
case 5:
case 6:
$thisfile_mpc_header['frame_count'] = $HeaderDWORD[1];
break;
default:
$ThisFileInfo['error'] = 'Expecting 4, 5 or 6 in version field, found '.$thisfile_mpc_header['stream_major_version'].' instead';
unset($ThisFileInfo['mpc']);
return false;
break;
}
if (($thisfile_mpc_header['stream_major_version'] > 4) && ($thisfile_mpc_header['block_size'] != 1)) {
$ThisFileInfo['warning'][] = 'Block size expected to be 1, actual value found: '.$thisfile_mpc_header['block_size'];
}
$thisfile_mpc_header['sample_rate'] = 44100; // AB: used by all files up to SV7
$ThisFileInfo['audio']['sample_rate'] = $thisfile_mpc_header['sample_rate'];
$thisfile_mpc_header['samples'] = $thisfile_mpc_header['frame_count'] * 1152 * $ThisFileInfo['audio']['channels'];
if ($thisfile_mpc_header['target_bitrate'] == 0) {
$ThisFileInfo['audio']['bitrate_mode'] = 'vbr';
} else {
$ThisFileInfo['audio']['bitrate_mode'] = 'cbr';
}
$ThisFileInfo['mpc']['bitrate'] = ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8 * 44100 / $thisfile_mpc_header['frame_count'] / 1152;
$ThisFileInfo['audio']['bitrate'] = $ThisFileInfo['mpc']['bitrate'];
$ThisFileInfo['audio']['encoder'] = 'SV'.$thisfile_mpc_header['stream_major_version'];
return true;
} else {
$ThisFileInfo['error'][] = 'Expecting "MP+" at offset '.$ThisFileInfo['avdataoffset'].', found "'.substr($MPCheaderData, $offset, 3).'"';
unset($ThisFileInfo['fileformat']);
unset($ThisFileInfo['mpc']);
return false;
}
// Continue with SV7+ handling
$StreamVersionByte = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 1));
$offset += 1;
$thisfile_mpc_header['stream_major_version'] = ($StreamVersionByte & 0x0F);
$thisfile_mpc_header['stream_minor_version'] = ($StreamVersionByte & 0xF0) >> 4;
$thisfile_mpc_header['frame_count'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
$offset += 4;
switch ($thisfile_mpc_header['stream_major_version']) {
case 7:
//$ThisFileInfo['fileformat'] = 'SV7';
break;
default:
$ThisFileInfo['error'][] = 'Only Musepack SV7 supported';
return false;
}
$FlagsDWORD1 = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
$offset += 4;
$thisfile_mpc_header['intensity_stereo'] = (bool) (($FlagsDWORD1 & 0x80000000) >> 31);
$thisfile_mpc_header['mid_side_stereo'] = (bool) (($FlagsDWORD1 & 0x40000000) >> 30);
$thisfile_mpc_header['max_subband'] = ($FlagsDWORD1 & 0x3F000000) >> 24;
$thisfile_mpc_header['raw']['profile'] = ($FlagsDWORD1 & 0x00F00000) >> 20;
$thisfile_mpc_header['begin_loud'] = (bool) (($FlagsDWORD1 & 0x00080000) >> 19);
$thisfile_mpc_header['end_loud'] = (bool) (($FlagsDWORD1 & 0x00040000) >> 18);
$thisfile_mpc_header['raw']['sample_rate'] = ($FlagsDWORD1 & 0x00030000) >> 16;
$thisfile_mpc_header['max_level'] = ($FlagsDWORD1 & 0x0000FFFF);
$thisfile_mpc_header['raw']['title_peak'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2));
$offset += 2;
$thisfile_mpc_header['raw']['title_gain'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2), true);
$offset += 2;
$thisfile_mpc_header['raw']['album_peak'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2));
$offset += 2;
$thisfile_mpc_header['raw']['album_gain'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2), true);
$offset += 2;
$FlagsDWORD2 = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
$offset += 4;
$thisfile_mpc_header['true_gapless'] = (bool) (($FlagsDWORD2 & 0x80000000) >> 31);
$thisfile_mpc_header['last_frame_length'] = ($FlagsDWORD2 & 0x7FF00000) >> 20;
$thisfile_mpc_header['raw']['not_sure_what'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 3));
$offset += 3;
$thisfile_mpc_header['raw']['encoder_version'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 1));
$offset += 1;
$thisfile_mpc_header['profile'] = $this->MPCprofileNameLookup($thisfile_mpc_header['raw']['profile']);
$thisfile_mpc_header['sample_rate'] = $this->MPCfrequencyLookup($thisfile_mpc_header['raw']['sample_rate']);
if ($thisfile_mpc_header['sample_rate'] == 0) {
$ThisFileInfo['error'][] = 'Corrupt MPC file: frequency == zero';
return false;
}
$ThisFileInfo['audio']['sample_rate'] = $thisfile_mpc_header['sample_rate'];
$thisfile_mpc_header['samples'] = ((($thisfile_mpc_header['frame_count'] - 1) * 1152) + $thisfile_mpc_header['last_frame_length']) * $ThisFileInfo['audio']['channels'];
$ThisFileInfo['playtime_seconds'] = ($thisfile_mpc_header['samples'] / $ThisFileInfo['audio']['channels']) / $ThisFileInfo['audio']['sample_rate'];
if ($ThisFileInfo['playtime_seconds'] == 0) {
$ThisFileInfo['error'][] = 'Corrupt MPC file: playtime_seconds == zero';
return false;
}
// add size of file header to avdataoffset - calc bitrate correctly + MD5 data
$ThisFileInfo['avdataoffset'] += $thisfile_mpc_header['size'];
$ThisFileInfo['audio']['bitrate'] = (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8) / $ThisFileInfo['playtime_seconds'];
$thisfile_mpc_header['title_peak'] = $thisfile_mpc_header['raw']['title_peak'];
$thisfile_mpc_header['title_peak_db'] = $this->MPCpeakDBLookup($thisfile_mpc_header['title_peak']);
if ($thisfile_mpc_header['raw']['title_gain'] < 0) {
$thisfile_mpc_header['title_gain_db'] = (float) (32768 + $thisfile_mpc_header['raw']['title_gain']) / -100;
} else {
$thisfile_mpc_header['title_gain_db'] = (float) $thisfile_mpc_header['raw']['title_gain'] / 100;
}
$thisfile_mpc_header['album_peak'] = $thisfile_mpc_header['raw']['album_peak'];
$thisfile_mpc_header['album_peak_db'] = $this->MPCpeakDBLookup($thisfile_mpc_header['album_peak']);
if ($thisfile_mpc_header['raw']['album_gain'] < 0) {
$thisfile_mpc_header['album_gain_db'] = (float) (32768 + $thisfile_mpc_header['raw']['album_gain']) / -100;
} else {
$thisfile_mpc_header['album_gain_db'] = (float) $thisfile_mpc_header['raw']['album_gain'] / 100;;
}
$thisfile_mpc_header['encoder_version'] = $this->MPCencoderVersionLookup($thisfile_mpc_header['raw']['encoder_version']);
$ThisFileInfo['replay_gain']['track']['adjustment'] = $thisfile_mpc_header['title_gain_db'];
$ThisFileInfo['replay_gain']['album']['adjustment'] = $thisfile_mpc_header['album_gain_db'];
if ($thisfile_mpc_header['title_peak'] > 0) {
$ThisFileInfo['replay_gain']['track']['peak'] = $thisfile_mpc_header['title_peak'];
} elseif (round($thisfile_mpc_header['max_level'] * 1.18) > 0) {
$ThisFileInfo['replay_gain']['track']['peak'] = getid3_lib::CastAsInt(round($thisfile_mpc_header['max_level'] * 1.18)); // why? I don't know - see mppdec.c
}
if ($thisfile_mpc_header['album_peak'] > 0) {
$ThisFileInfo['replay_gain']['album']['peak'] = $thisfile_mpc_header['album_peak'];
}
//$ThisFileInfo['audio']['encoder'] = 'SV'.$thisfile_mpc_header['stream_major_version'].'.'.$thisfile_mpc_header['stream_minor_version'].', '.$thisfile_mpc_header['encoder_version'];
$ThisFileInfo['audio']['encoder'] = $thisfile_mpc_header['encoder_version'];
$ThisFileInfo['audio']['encoder_options'] = $thisfile_mpc_header['profile'];
return true;
}
function MPCprofileNameLookup($profileid) {
static $MPCprofileNameLookup = array(
0 => 'no profile',
1 => 'Experimental',
2 => 'unused',
3 => 'unused',
4 => 'unused',
5 => 'below Telephone (q = 0.0)',
6 => 'below Telephone (q = 1.0)',
7 => 'Telephone (q = 2.0)',
8 => 'Thumb (q = 3.0)',
9 => 'Radio (q = 4.0)',
10 => 'Standard (q = 5.0)',
11 => 'Extreme (q = 6.0)',
12 => 'Insane (q = 7.0)',
13 => 'BrainDead (q = 8.0)',
14 => 'above BrainDead (q = 9.0)',
15 => 'above BrainDead (q = 10.0)'
);
return (isset($MPCprofileNameLookup[$profileid]) ? $MPCprofileNameLookup[$profileid] : 'invalid');
}
function MPCfrequencyLookup($frequencyid) {
static $MPCfrequencyLookup = array(
0 => 44100,
1 => 48000,
2 => 37800,
3 => 32000
);
return (isset($MPCfrequencyLookup[$frequencyid]) ? $MPCfrequencyLookup[$frequencyid] : 'invalid');
}
function MPCpeakDBLookup($intvalue) {
if ($intvalue > 0) {
return ((log10($intvalue) / log10(2)) - 15) * 6;
}
return false;
}
function MPCencoderVersionLookup($encoderversion) {
//Encoder version * 100 (106 = 1.06)
//EncoderVersion % 10 == 0 Release (1.0)
//EncoderVersion % 2 == 0 Beta (1.06)
//EncoderVersion % 2 == 1 Alpha (1.05a...z)
if ($encoderversion == 0) {
// very old version, not known exactly which
return 'Buschmann v1.7.0-v1.7.9 or Klemm v0.90-v1.05';
}
if (($encoderversion % 10) == 0) {
// release version
return number_format($encoderversion / 100, 2);
} elseif (($encoderversion % 2) == 0) {
// beta version
return number_format($encoderversion / 100, 2).' beta';
}
// alpha version
return number_format($encoderversion / 100, 2).' alpha';
}
}
?>
|
