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Public Member Functions
getid3_la Class Reference
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Public Member Functions

 getid3_la (&$fd, &$ThisFileInfo)

Detailed Description

Definition at line 18 of file module.audio.la.php.

Member Function Documentation

getid3_la::getid3_la ( &  $fd,
&  $ThisFileInfo 
)

Definition at line 21 of file module.audio.la.php.

References GETID3_FREAD_BUFFER_SIZE, getid3_lib\LittleEndian2Int(), and getid3_lib\PrintHexBytes().

{
$offset = 0;
fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);
$rawdata = fread($fd, GETID3_FREAD_BUFFER_SIZE);
switch (substr($rawdata, $offset, 4)) {
case 'LA02':
case 'LA03':
case 'LA04':
$ThisFileInfo['fileformat'] = 'la';
$ThisFileInfo['audio']['dataformat'] = 'la';
$ThisFileInfo['audio']['lossless'] = true;
$ThisFileInfo['la']['version_major'] = (int) substr($rawdata, $offset + 2, 1);
$ThisFileInfo['la']['version_minor'] = (int) substr($rawdata, $offset + 3, 1);
$ThisFileInfo['la']['version'] = (float) $ThisFileInfo['la']['version_major'] + ($ThisFileInfo['la']['version_minor'] / 10);
$offset += 4;
$ThisFileInfo['la']['uncompressed_size'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
$offset += 4;
if ($ThisFileInfo['la']['uncompressed_size'] == 0) {
$ThisFileInfo['error'][] = 'Corrupt LA file: uncompressed_size == zero';
return false;
}
$WAVEchunk = substr($rawdata, $offset, 4);
if ($WAVEchunk !== 'WAVE') {
$ThisFileInfo['error'][] = 'Expected "WAVE" ('.getid3_lib::PrintHexBytes('WAVE').') at offset '.$offset.', found "'.$WAVEchunk.'" ('.getid3_lib::PrintHexBytes($WAVEchunk).') instead.';
return false;
}
$offset += 4;
$ThisFileInfo['la']['fmt_size'] = 24;
if ($ThisFileInfo['la']['version'] >= 0.3) {
$ThisFileInfo['la']['fmt_size'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
$ThisFileInfo['la']['header_size'] = 49 + $ThisFileInfo['la']['fmt_size'] - 24;
$offset += 4;
} else {
// version 0.2 didn't support additional data blocks
$ThisFileInfo['la']['header_size'] = 41;
}
$fmt_chunk = substr($rawdata, $offset, 4);
if ($fmt_chunk !== 'fmt ') {
$ThisFileInfo['error'][] = 'Expected "fmt " ('.getid3_lib::PrintHexBytes('fmt ').') at offset '.$offset.', found "'.$fmt_chunk.'" ('.getid3_lib::PrintHexBytes($fmt_chunk).') instead.';
return false;
}
$offset += 4;
$fmt_size = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
$offset += 4;
$ThisFileInfo['la']['raw']['format'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 2));
$offset += 2;
$ThisFileInfo['la']['channels'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 2));
$offset += 2;
if ($ThisFileInfo['la']['channels'] == 0) {
$ThisFileInfo['error'][] = 'Corrupt LA file: channels == zero';
return false;
}
$ThisFileInfo['la']['sample_rate'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
$offset += 4;
if ($ThisFileInfo['la']['sample_rate'] == 0) {
$ThisFileInfo['error'][] = 'Corrupt LA file: sample_rate == zero';
return false;
}
$ThisFileInfo['la']['bytes_per_second'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
$offset += 4;
$ThisFileInfo['la']['bytes_per_sample'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 2));
$offset += 2;
$ThisFileInfo['la']['bits_per_sample'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 2));
$offset += 2;
$ThisFileInfo['la']['samples'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
$offset += 4;
$ThisFileInfo['la']['raw']['flags'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 1));
$offset += 1;
$ThisFileInfo['la']['flags']['seekable'] = (bool) ($ThisFileInfo['la']['raw']['flags'] & 0x01);
if ($ThisFileInfo['la']['version'] >= 0.4) {
$ThisFileInfo['la']['flags']['high_compression'] = (bool) ($ThisFileInfo['la']['raw']['flags'] & 0x02);
}
$ThisFileInfo['la']['original_crc'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
$offset += 4;
// mikeØbevin*de
// Basically, the blocksize/seekevery are 61440/19 in La0.4 and 73728/16
// in earlier versions. A seekpoint is added every blocksize * seekevery
// samples, so 4 * int(totalSamples / (blockSize * seekEvery)) should
// give the number of bytes used for the seekpoints. Of course, if seeking
// is disabled, there are no seekpoints stored.
if ($ThisFileInfo['la']['version'] >= 0.4) {
$ThisFileInfo['la']['blocksize'] = 61440;
$ThisFileInfo['la']['seekevery'] = 19;
} else {
$ThisFileInfo['la']['blocksize'] = 73728;
$ThisFileInfo['la']['seekevery'] = 16;
}
$ThisFileInfo['la']['seekpoint_count'] = 0;
if ($ThisFileInfo['la']['flags']['seekable']) {
$ThisFileInfo['la']['seekpoint_count'] = floor($ThisFileInfo['la']['samples'] / ($ThisFileInfo['la']['blocksize'] * $ThisFileInfo['la']['seekevery']));
for ($i = 0; $i < $ThisFileInfo['la']['seekpoint_count']; $i++) {
$ThisFileInfo['la']['seekpoints'][] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
$offset += 4;
}
}
if ($ThisFileInfo['la']['version'] >= 0.3) {
// Following the main header information, the program outputs all of the
// seekpoints. Following these is what I called the 'footer start',
// i.e. the position immediately after the La audio data is finished.
$ThisFileInfo['la']['footerstart'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
$offset += 4;
if ($ThisFileInfo['la']['footerstart'] > $ThisFileInfo['filesize']) {
$ThisFileInfo['warning'][] = 'FooterStart value points to offset '.$ThisFileInfo['la']['footerstart'].' which is beyond end-of-file ('.$ThisFileInfo['filesize'].')';
$ThisFileInfo['la']['footerstart'] = $ThisFileInfo['filesize'];
}
} else {
// La v0.2 didn't have FooterStart value
$ThisFileInfo['la']['footerstart'] = $ThisFileInfo['avdataend'];
}
if ($ThisFileInfo['la']['footerstart'] < $ThisFileInfo['avdataend']) {
if ($RIFFtempfilename = tempnam('*', 'id3')) {
if ($RIFF_fp = fopen($RIFFtempfilename, 'w+b')) {
$RIFFdata = 'WAVE';
if ($ThisFileInfo['la']['version'] == 0.2) {
$RIFFdata .= substr($rawdata, 12, 24);
} else {
$RIFFdata .= substr($rawdata, 16, 24);
}
if ($ThisFileInfo['la']['footerstart'] < $ThisFileInfo['avdataend']) {
fseek($fd, $ThisFileInfo['la']['footerstart'], SEEK_SET);
$RIFFdata .= fread($fd, $ThisFileInfo['avdataend'] - $ThisFileInfo['la']['footerstart']);
}
$RIFFdata = 'RIFF'.getid3_lib::LittleEndian2String(strlen($RIFFdata), 4, false).$RIFFdata;
fwrite($RIFF_fp, $RIFFdata, strlen($RIFFdata));
$dummy = $ThisFileInfo;
$dummy['filesize'] = strlen($RIFFdata);
$dummy['avdataoffset'] = 0;
$dummy['avdataend'] = $dummy['filesize'];
$riff = new getid3_riff($RIFF_fp, $dummy);
if (empty($dummy['error'])) {
$ThisFileInfo['riff'] = $dummy['riff'];
} else {
$ThisFileInfo['warning'][] = 'Error parsing RIFF portion of La file: '.implode($dummy['error']);
}
unset($dummy);
fclose($RIFF_fp);
}
unlink($RIFFtempfilename);
}
}
// $ThisFileInfo['avdataoffset'] should be zero to begin with, but just in case it's not, include the addition anyway
$ThisFileInfo['avdataend'] = $ThisFileInfo['avdataoffset'] + $ThisFileInfo['la']['footerstart'];
$ThisFileInfo['avdataoffset'] = $ThisFileInfo['avdataoffset'] + $offset;
//$ThisFileInfo['la']['codec'] = RIFFwFormatTagLookup($ThisFileInfo['la']['raw']['format']);
$ThisFileInfo['la']['compression_ratio'] = (float) (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) / $ThisFileInfo['la']['uncompressed_size']);
$ThisFileInfo['playtime_seconds'] = (float) ($ThisFileInfo['la']['samples'] / $ThisFileInfo['la']['sample_rate']) / $ThisFileInfo['la']['channels'];
if ($ThisFileInfo['playtime_seconds'] == 0) {
$ThisFileInfo['error'][] = 'Corrupt LA file: playtime_seconds == zero';
return false;
}
$ThisFileInfo['audio']['bitrate'] = ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8 / $ThisFileInfo['playtime_seconds'];
//$ThisFileInfo['audio']['codec'] = $ThisFileInfo['la']['codec'];
$ThisFileInfo['audio']['bits_per_sample'] = $ThisFileInfo['la']['bits_per_sample'];
break;
default:
if (substr($rawdata, $offset, 2) == 'LA') {
$ThisFileInfo['error'][] = 'This version of getID3() (v'.GETID3_VERSION.') doesn\'t support LA version '.substr($rawdata, $offset + 2, 1).'.'.substr($rawdata, $offset + 3, 1).' which this appears to be - check http://getid3.sourceforge.net for updates.';
} else {
$ThisFileInfo['error'][] = 'Not a LA (Lossless-Audio) file';
}
return false;
break;
}
$ThisFileInfo['audio']['channels'] = $ThisFileInfo['la']['channels'];
$ThisFileInfo['audio']['sample_rate'] = (int) $ThisFileInfo['la']['sample_rate'];
$ThisFileInfo['audio']['encoder'] = 'LA v'.$ThisFileInfo['la']['version'];
return true;
}

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The documentation for this class was generated from the following file: