function FLACparseMETAdata(&$fd, &$ThisFileInfo)
{
do {
$METAdataBlockOffset = ftell($fd);
$METAdataBlockHeader = fread($fd, 4);
$METAdataLastBlockFlag = (bool) (getid3_lib::BigEndian2Int(substr($METAdataBlockHeader, 0, 1)) & 0x80);
$METAdataBlockType = getid3_lib::BigEndian2Int(substr($METAdataBlockHeader, 0, 1)) & 0x7f;
$METAdataBlockLength = getid3_lib::BigEndian2Int(substr($METAdataBlockHeader, 1, 3));
$METAdataBlockTypeText = getid3_flac::FLACmetaBlockTypeLookup($METAdataBlockType);
$ThisFileInfo['flac']["{$METAdataBlockTypeText}"]['raw']['offset'] = $METAdataBlockOffset;
$ThisFileInfo['flac']["{$METAdataBlockTypeText}"]['raw']['last_meta_block'] = $METAdataLastBlockFlag;
$ThisFileInfo['flac']["{$METAdataBlockTypeText}"]['raw']['block_type'] = $METAdataBlockType;
$ThisFileInfo['flac']["{$METAdataBlockTypeText}"]['raw']['block_type_text'] = $METAdataBlockTypeText;
$ThisFileInfo['flac']["{$METAdataBlockTypeText}"]['raw']['block_length'] = $METAdataBlockLength;
$ThisFileInfo['flac']["{$METAdataBlockTypeText}"]['raw']['block_data'] = fread($fd, $METAdataBlockLength);
$ThisFileInfo['avdataoffset'] = ftell($fd);
switch ($METAdataBlockTypeText) {
case 'STREAMINFO':
if (!getid3_flac::FLACparseSTREAMINFO($ThisFileInfo['flac']["{$METAdataBlockTypeText}"]['raw']['block_data'], $ThisFileInfo)) {
return false;
}
break;
case 'PADDING':
// ignore
break;
case 'APPLICATION':
if (!getid3_flac::FLACparseAPPLICATION($ThisFileInfo['flac']["{$METAdataBlockTypeText}"]['raw']['block_data'], $ThisFileInfo)) {
return false;
}
break;
case 'SEEKTABLE':
if (!getid3_flac::FLACparseSEEKTABLE($ThisFileInfo['flac']["{$METAdataBlockTypeText}"]['raw']['block_data'], $ThisFileInfo)) {
return false;
}
break;
case 'VORBIS_COMMENT':
$OldOffset = ftell($fd);
fseek($fd, 0 - $METAdataBlockLength, SEEK_CUR);
getid3_ogg::ParseVorbisCommentsFilepointer($fd, $ThisFileInfo);
fseek($fd, $OldOffset, SEEK_SET);
break;
case 'CUESHEET':
if (!getid3_flac::FLACparseCUESHEET($ThisFileInfo['flac']["{$METAdataBlockTypeText}"]['raw']['block_data'], $ThisFileInfo)) {
return false;
}
break;
default:
$ThisFileInfo['warning'][] = 'Unhandled METADATA_BLOCK_HEADER.BLOCK_TYPE (' . $METAdataBlockType . ') at offset ' . $METAdataBlockOffset;
break;
}
} while ($METAdataLastBlockFlag === false);
if (isset($ThisFileInfo['flac']['STREAMINFO'])) {
$ThisFileInfo['flac']['compressed_audio_bytes'] = $ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset'];
$ThisFileInfo['flac']['uncompressed_audio_bytes'] = $ThisFileInfo['flac']['STREAMINFO']['samples_stream'] * $ThisFileInfo['flac']['STREAMINFO']['channels'] * ($ThisFileInfo['flac']['STREAMINFO']['bits_per_sample'] / 8);
if ($ThisFileInfo['flac']['uncompressed_audio_bytes'] == 0) {
$ThisFileInfo['error'][] = 'Corrupt FLAC file: uncompressed_audio_bytes == zero';
return false;
}
$ThisFileInfo['flac']['compression_ratio'] = $ThisFileInfo['flac']['compressed_audio_bytes'] / $ThisFileInfo['flac']['uncompressed_audio_bytes'];
}
// set md5_data_source - built into flac 0.5+
if (isset($ThisFileInfo['flac']['STREAMINFO']['audio_signature'])) {
if ($ThisFileInfo['flac']['STREAMINFO']['audio_signature'] === str_repeat("", 16)) {
$ThisFileInfo['warning'][] = 'FLAC STREAMINFO.audio_signature is null (known issue with libOggFLAC)';
} else {
$ThisFileInfo['md5_data_source'] = '';
$md5 = $ThisFileInfo['flac']['STREAMINFO']['audio_signature'];
for ($i = 0; $i < strlen($md5); $i++) {
$ThisFileInfo['md5_data_source'] .= str_pad(dechex(ord($md5[$i])), 2, '00', STR_PAD_LEFT);
}
if (!preg_match('/^[0-9a-f]{32}$/', $ThisFileInfo['md5_data_source'])) {
unset($ThisFileInfo['md5_data_source']);
}
}
}
$ThisFileInfo['audio']['bits_per_sample'] = $ThisFileInfo['flac']['STREAMINFO']['bits_per_sample'];
if ($ThisFileInfo['audio']['bits_per_sample'] == 8) {
// special case
// must invert sign bit on all data bytes before MD5'ing to match FLAC's calculated value
// MD5sum calculates on unsigned bytes, but FLAC calculated MD5 on 8-bit audio data as signed
$ThisFileInfo['warning'][] = 'FLAC calculates MD5 data strangely on 8-bit audio, so the stored md5_data_source value will not match the decoded WAV file';
}
if (!empty($ThisFileInfo['ogg']['vendor'])) {
$ThisFileInfo['audio']['encoder'] = $ThisFileInfo['ogg']['vendor'];
}
return true;
}
