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|
<?php
// +----------------------------------------------------------------------+
// | PHP version 5 |
// +----------------------------------------------------------------------+
// | Copyright (c) 2002-2006 James Heinrich, Allan Hansen |
// +----------------------------------------------------------------------+
// | This source file is subject to version 2 of the GPL license, |
// | that is bundled with this package in the file license.txt and is |
// | available through the world-wide-web at the following url: |
// | http://www.gnu.org/copyleft/gpl.html |
// +----------------------------------------------------------------------+
// | getID3() - http://getid3.sourceforge.net or http://www.getid3.org |
// +----------------------------------------------------------------------+
// | Authors: James Heinrich <info��etid3*org> |
// | Allan Hansen <ah��artemis*dk> |
// +----------------------------------------------------------------------+
// | module.audio.mpc.php |
// | Module for analyzing Musepack/MPEG+ Audio files |
// | dependencies: NONE |
// +----------------------------------------------------------------------+
//
// $Id$
class getid3_mpc8 extends getid3_handler
{
public function Analyze() {
$getid3 = $this->getid3;
$getid3->info['fileformat'] = 'mpc';
$getid3->info['audio']['dataformat'] = 'mpc';
$getid3->info['audio']['bitrate_mode'] = 'vbr';
$getid3->info['audio']['lossless'] = false;
fseek($getid3->fp, $getid3->info['avdataoffset'], SEEK_SET);
$MPCheaderData = fread($getid3->fp, 4);
$getid3->info['mpc']['header']['preamble'] = substr($MPCheaderData, 0, 4); // should be 'MPCK' (SV8) or 'MP+' (SV7), otherwise possible stream data (SV4-SV6)
if (ereg('^MPCK', $getid3->info['mpc']['header']['preamble'])) {
// this is SV8
// http://trac.musepack.net/trac/wiki/SV8Specification
$thisfile_mpc_header = &$getid3->info['mpc']['header'];
$keyNameSize = 2;
$maxHandledPacketLength = 9; // specs say: "n*8; 0 < n < 10"
$offset = ftell($getid3->fp);
while ($offset < $getid3->info['avdataend']) {
$thisPacket = array();
$thisPacket['offset'] = $offset;
$packet_offset = 0;
// Size is a variable-size field, could be 1-4 bytes (possibly more?)
// read enough data in and figure out the exact size later
$MPCheaderData = fread($getid3->fp, $keyNameSize + $maxHandledPacketLength);
$packet_offset += $keyNameSize;
$thisPacket['key'] = substr($MPCheaderData, 0, $keyNameSize);
$thisPacket['key_name'] = $this->MPCsv8PacketName($thisPacket['key']);
if ($thisPacket['key'] == $thisPacket['key_name']) {
$getid3->info['error'][] = 'Found unexpected key value "'.$thisPacket['key'].'" at offset '.$thisPacket['offset'];
return false;
}
$packetLength = 0;
$thisPacket['packet_size'] = $this->SV8variableLengthInteger(substr($MPCheaderData, $keyNameSize), $packetLength); // includes keyname and packet_size field
if ($thisPacket['packet_size'] === false) {
$getid3->info['error'][] = 'Did not find expected packet length within '.$maxHandledPacketLength.' bytes at offset '.($thisPacket['offset'] + $keyNameSize);
return false;
}
$packet_offset += $packetLength;
$offset += $thisPacket['packet_size'];
switch ($thisPacket['key']) {
case 'SH': // Stream Header
$moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength;
if ($moreBytesToRead > 0) {
$MPCheaderData .= fread($getid3->fp, $moreBytesToRead);
}
$thisPacket['crc'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 4));
$packet_offset += 4;
$thisPacket['stream_version'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
$packet_offset += 1;
$packetLength = 0;
$thisPacket['sample_count'] = $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength);
$packet_offset += $packetLength;
$packetLength = 0;
$thisPacket['beginning_silence'] = $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength);
$packet_offset += $packetLength;
$otherUsefulData = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
$packet_offset += 2;
$thisPacket['sample_frequency_raw'] = (($otherUsefulData & 0xE000) >> 13);
$thisPacket['max_bands_used'] = (($otherUsefulData & 0x1F00) >> 8);
$thisPacket['channels'] = (($otherUsefulData & 0x00F0) >> 4) + 1;
$thisPacket['ms_used'] = (bool) (($otherUsefulData & 0x0008) >> 3);
$thisPacket['audio_block_frames'] = (($otherUsefulData & 0x0007) >> 0);
$thisPacket['sample_frequency'] = $this->MPCfrequencyLookup($thisPacket['sample_frequency_raw']);
$thisfile_mpc_header['mid_side_stereo'] = $thisPacket['ms_used'];
$thisfile_mpc_header['sample_rate'] = $thisPacket['sample_frequency'];
$thisfile_mpc_header['samples'] = $thisPacket['sample_count'];
$thisfile_mpc_header['stream_version_major'] = $thisPacket['stream_version'];
$getid3->info['audio']['channels'] = $thisPacket['channels'];
$getid3->info['audio']['sample_rate'] = $thisPacket['sample_frequency'];
$getid3->info['playtime_seconds'] = $thisPacket['sample_count'] / $thisPacket['sample_frequency'];
$getid3->info['audio']['bitrate'] = (($getid3->info['avdataend'] - $getid3->info['avdataoffset']) * 8) / $getid3->info['playtime_seconds'];
break;
case 'RG': // Replay Gain
$moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength;
if ($moreBytesToRead > 0) {
$MPCheaderData .= fread($getid3->fp, $moreBytesToRead);
}
$thisPacket['replaygain_version'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
$packet_offset += 1;
$thisPacket['replaygain_title_gain'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
$packet_offset += 2;
$thisPacket['replaygain_title_peak'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
$packet_offset += 2;
$thisPacket['replaygain_album_gain'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
$packet_offset += 2;
$thisPacket['replaygain_album_peak'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
$packet_offset += 2;
if ($thisPacket['replaygain_title_gain']) { $getid3->info['replay_gain']['title']['gain'] = $thisPacket['replaygain_title_gain']; }
if ($thisPacket['replaygain_title_peak']) { $getid3->info['replay_gain']['title']['peak'] = $thisPacket['replaygain_title_peak']; }
if ($thisPacket['replaygain_album_gain']) { $getid3->info['replay_gain']['album']['gain'] = $thisPacket['replaygain_album_gain']; }
if ($thisPacket['replaygain_album_peak']) { $getid3->info['replay_gain']['album']['peak'] = $thisPacket['replaygain_album_peak']; }
break;
case 'EI': // Encoder Info
$moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength;
if ($moreBytesToRead > 0) {
$MPCheaderData .= fread($getid3->fp, $moreBytesToRead);
}
$profile_pns = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
$packet_offset += 1;
$quality_int = (($profile_pns & 0xF0) >> 4);
$quality_dec = (($profile_pns & 0x0E) >> 3);
$thisPacket['quality'] = (float) $quality_int + ($quality_dec / 8);
$thisPacket['pns_tool'] = (bool) (($profile_pns & 0x01) >> 0);
$thisPacket['version_major'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
$packet_offset += 1;
$thisPacket['version_minor'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
$packet_offset += 1;
$thisPacket['version_build'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
$packet_offset += 1;
$thisPacket['version'] = $thisPacket['version_major'].'.'.$thisPacket['version_minor'].'.'.$thisPacket['version_build'];
$getid3->info['audio']['encoder'] = 'MPC v'.$thisPacket['version'].' ('.(($thisPacket['version_minor'] % 2) ? 'unstable' : 'stable').')';
$thisfile_mpc_header['encoder_version'] = $getid3->info['audio']['encoder'];
//$thisfile_mpc_header['quality'] = (float) ($thisPacket['quality'] / 1.5875); // values can range from 0.000 to 15.875, mapped to qualities of 0.0 to 10.0
$thisfile_mpc_header['quality'] = (float) ($thisPacket['quality'] - 5); // values can range from 0.000 to 15.875, of which 0..4 are "reserved/experimental", and 5..15 are mapped to qualities of 0.0 to 10.0
break;
case 'SO': // Seek Table Offset
$packetLength = 0;
$thisPacket['seek_table_offset'] = $thisPacket['offset'] + $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength);
$packet_offset += $packetLength;
break;
case 'ST': // Seek Table
case 'SE': // Stream End
case 'AP': // Audio Data
// nothing useful here, just skip this packet
$thisPacket = array();
break;
default:
$getid3->info['error'][] = 'Found unhandled key type "'.$thisPacket['key'].'" at offset '.$thisPacket['offset'];
return false;
break;
}
if (!empty($thisPacket)) {
$getid3->info['mpc']['packets'][] = $thisPacket;
}
fseek($getid3->fp, $offset);
}
$thisfile_mpc_header['size'] = $offset;
return true;
} else {
$getid3->info['error'][] = 'Expecting "MP+" or "MPCK" at offset '.$getid3->info['avdataoffset'].', found "'.substr($MPCheaderData, 0, 4).'"';
unset($getid3->info['fileformat']);
unset($getid3->info['mpc']);
return false;
}
return false;
}
public static function MPCprofileNameLookup($profileid) {
static $lookup = array (
0 => 'no profile',
1 => 'Experimental',
2 => 'unused',
3 => 'unused',
4 => 'unused',
5 => 'below Telephone (q = 0.0)',
6 => 'below Telephone (q = 1.0)',
7 => 'Telephone (q = 2.0)',
8 => 'Thumb (q = 3.0)',
9 => 'Radio (q = 4.0)',
10 => 'Standard (q = 5.0)',
11 => 'Extreme (q = 6.0)',
12 => 'Insane (q = 7.0)',
13 => 'BrainDead (q = 8.0)',
14 => 'above BrainDead (q = 9.0)',
15 => 'above BrainDead (q = 10.0)'
);
return (isset($lookup[$profileid]) ? $lookup[$profileid] : 'invalid');
}
public static function MPCfrequencyLookup($frequencyid) {
static $lookup = array (
0 => 44100,
1 => 48000,
2 => 37800,
3 => 32000
);
return (isset($lookup[$frequencyid]) ? $lookup[$frequencyid] : 'invalid');
}
public static function MPCpeakDBLookup($int_value) {
if ($int_value > 0) {
return ((log10($int_value) / log10(2)) - 15) * 6;
}
return false;
}
public static function MPCencoderVersionLookup($encoder_version) {
//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 ($encoder_version == 0) {
// very old version, not known exactly which
return 'Buschmann v1.7.0-v1.7.9 or Klemm v0.90-v1.05';
}
if (($encoder_version % 10) == 0) {
// release version
return number_format($encoder_version / 100, 2);
} elseif (($encoder_version % 2) == 0) {
// beta version
return number_format($encoder_version / 100, 2).' beta';
}
// alpha version
return number_format($encoder_version / 100, 2).' alpha';
}
public static function SV8variableLengthInteger($data, &$packetLength, $maxHandledPacketLength=9) {
$packet_size = 0;
for ($packetLength = 1; $packetLength <= $maxHandledPacketLength; $packetLength++) {
// variable-length size field:
// bits, big-endian
// 0xxx xxxx - value 0 to 2^7-1
// 1xxx xxxx 0xxx xxxx - value 0 to 2^14-1
// 1xxx xxxx 1xxx xxxx 0xxx xxxx - value 0 to 2^21-1
// 1xxx xxxx 1xxx xxxx 1xxx xxxx 0xxx xxxx - value 0 to 2^28-1
// ...
$thisbyte = ord(substr($data, ($packetLength - 1), 1));
// look through bytes until find a byte with MSB==0
$packet_size = ($packet_size << 7);
$packet_size = ($packet_size | ($thisbyte & 0x7F));
if (($thisbyte & 0x80) === 0) {
break;
}
if ($packetLength >= $maxHandledPacketLength) {
return false;
}
}
return $packet_size;
}
public static function MPCsv8PacketName($packetKey) {
static $MPCsv8PacketName = array();
if (empty($MPCsv8PacketName)) {
$MPCsv8PacketName = array(
'AP' => 'Audio Packet',
'CT' => 'Chapter Tag',
'EI' => 'Encoder Info',
'RG' => 'Replay Gain',
'SE' => 'Stream End',
'SH' => 'Stream Header',
'SO' => 'Seek Table Offset',
'ST' => 'Seek Table',
);
}
return (isset($MPCsv8PacketName[$packetKey]) ? $MPCsv8PacketName[$packetKey] : $packetKey);
}
}
?>
|
