<?php

/////////////////////////////////////////////////////////////////
/// getID3() by James Heinrich <info@getid3.org> //
// available at https://github.com/JamesHeinrich/getID3 //
// or https://www.getid3.org //
// or http://getid3.sourceforge.net //
// see readme.txt for more details //
/////////////////////////////////////////////////////////////////
// //
// module.audio.flac.php //
// module for analyzing FLAC and OggFLAC audio files //
// dependencies: module.audio.ogg.php //
// ///
/////////////////////////////////////////////////////////////////

if (!defined('GETID3_INCLUDEPATH')) { // prevent path-exposing attacks that access modules directly on public webservers
exit;
}
getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio.ogg.php', __FILE__, true);

/**
* @tutorial http://flac.sourceforge.net/format.html
*/
class getid3_flac extends getid3_handler
{
const syncword = 'fLaC';

/**
* @return bool
*/
public function Analyze() {
$info = &$this->getid3->info;

$this->fseek($info['avdataoffset']);
$StreamMarker = $this->fread(4);
if ($StreamMarker != self::syncword) {
return $this->error('Expecting "'.getid3_lib::PrintHexBytes(self::syncword).'" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes($StreamMarker).'"');
}
$info['fileformat'] = 'flac';
$info['audio']['dataformat'] = 'flac';
$info['audio']['bitrate_mode'] = 'vbr';
$info['audio']['lossless'] = true;

// parse flac container
return $this->parseMETAdata();
}

/**
* @return bool
*/
public function parseMETAdata() {
$info = &$this->getid3->info;
do {
$BlockOffset = $this->ftell();
$BlockHeader = $this->fread(4);
$LBFBT = getid3_lib::BigEndian2Int(substr($BlockHeader, 0, 1)); // LBFBT = LastBlockFlag + BlockType
$LastBlockFlag = (bool) ($LBFBT & 0x80);
$BlockType = ($LBFBT & 0x7F);
$BlockLength = getid3_lib::BigEndian2Int(substr($BlockHeader, 1, 3));
$BlockTypeText = self::metaBlockTypeLookup($BlockType);

if (($BlockOffset + 4 + $BlockLength) > $info['avdataend']) {
$this->warning('METADATA_BLOCK_HEADER.BLOCK_TYPE ('.$BlockTypeText.') at offset '.$BlockOffset.' extends beyond end of file');
break;
}
if ($BlockLength < 1) {
if ($BlockTypeText != 'reserved') {
// probably supposed to be zero-length
$this->warning('METADATA_BLOCK_HEADER.BLOCK_LENGTH ('.$BlockTypeText.') at offset '.$BlockOffset.' is zero bytes');
continue;
}
$this->error('METADATA_BLOCK_HEADER.BLOCK_LENGTH ('.$BlockLength.') at offset '.$BlockOffset.' is invalid');
break;
}

$info['flac'][$BlockTypeText]['raw'] = array();
$BlockTypeText_raw = &$info['flac'][$BlockTypeText]['raw'];

$BlockTypeText_raw['offset'] = $BlockOffset;
$BlockTypeText_raw['last_meta_block'] = $LastBlockFlag;
$BlockTypeText_raw['block_type'] = $BlockType;
$BlockTypeText_raw['block_type_text'] = $BlockTypeText;
$BlockTypeText_raw['block_length'] = $BlockLength;
if ($BlockTypeText_raw['block_type'] != 0x06) { // do not read attachment data automatically
$BlockTypeText_raw['block_data'] = $this->fread($BlockLength);
}

switch ($BlockTypeText) {
case 'STREAMINFO': // 0x00
if (!$this->parseSTREAMINFO($BlockTypeText_raw['block_data'])) {
return false;
}
break;

case 'PADDING': // 0x01
unset($info['flac']['PADDING']); // ignore
break;

case 'APPLICATION': // 0x02
if (!$this->parseAPPLICATION($BlockTypeText_raw['block_data'])) {
return false;
}
break;

case 'SEEKTABLE': // 0x03
if (!$this->parseSEEKTABLE($BlockTypeText_raw['block_data'])) {
return false;
}
break;

case 'VORBIS_COMMENT': // 0x04
if (!$this->parseVORBIS_COMMENT($BlockTypeText_raw['block_data'])) {
return false;
}
break;

case 'CUESHEET': // 0x05
if (!$this->parseCUESHEET($BlockTypeText_raw['block_data'])) {
return false;
}
break;

case 'PICTURE': // 0x06
if (!$this->parsePICTURE()) {
return false;
}
break;

default:
$this->warning('Unhandled METADATA_BLOCK_HEADER.BLOCK_TYPE ('.$BlockType.') at offset '.$BlockOffset);
}

unset($info['flac'][$BlockTypeText]['raw']);
$info['avdataoffset'] = $this->ftell();
}
while ($LastBlockFlag === false);

// handle tags
if (!empty($info['flac']['VORBIS_COMMENT']['comments'])) {
$info['flac']['comments'] = $info['flac']['VORBIS_COMMENT']['comments'];
}
if (!empty($info['flac']['VORBIS_COMMENT']['vendor'])) {
$info['audio']['encoder'] = str_replace('reference ', '', $info['flac']['VORBIS_COMMENT']['vendor']);
}

// copy attachments to 'comments' array if nesesary
if (isset($info['flac']['PICTURE']) && ($this->getid3->option_save_attachments !== getID3::ATTACHMENTS_NONE)) {
foreach ($info['flac']['PICTURE'] as $entry) {
if (!empty($entry['data'])) {
if (!isset($info['flac']['comments']['picture'])) {
$info['flac']['comments']['picture'] = array();
}
$comments_picture_data = array();
foreach (array('data', 'image_mime', 'image_width', 'image_height', 'imagetype', 'picturetype', 'description', 'datalength') as $picture_key) {
if (isset($entry[$picture_key])) {
$comments_picture_data[$picture_key] = $entry[$picture_key];
}
}
$info['flac']['comments']['picture'][] = $comments_picture_data;
unset($comments_picture_data);
}
}
}

if (isset($info['flac']['STREAMINFO'])) {
if (!$this->isDependencyFor('matroska')) {
$info['flac']['compressed_audio_bytes'] = $info['avdataend'] - $info['avdataoffset'];
}
$info['flac']['uncompressed_audio_bytes'] = $info['flac']['STREAMINFO']['samples_stream'] * $info['flac']['STREAMINFO']['channels'] * ($info['flac']['STREAMINFO']['bits_per_sample'] / 8);
if ($info['flac']['uncompressed_audio_bytes'] == 0) {
return $this->error('Corrupt FLAC file: uncompressed_audio_bytes == zero');
}
if (!empty($info['flac']['compressed_audio_bytes'])) {
$info['flac']['compression_ratio'] = $info['flac']['compressed_audio_bytes'] / $info['flac']['uncompressed_audio_bytes'];
}
}

// set md5_data_source - built into flac 0.5+
if (isset($info['flac']['STREAMINFO']['audio_signature'])) {

if ($info['flac']['STREAMINFO']['audio_signature'] === str_repeat("\x00", 16)) {
$this->warning('FLAC STREAMINFO.audio_signature is null (known issue with libOggFLAC)');
}
else {
$info['md5_data_source'] = '';
$md5 = $info['flac']['STREAMINFO']['audio_signature'];
for ($i = 0; $i < strlen($md5); $i++) {
$info['md5_data_source'] .= str_pad(dechex(ord($md5[$i])), 2, '00', STR_PAD_LEFT);
}
if (!preg_match('/^[0-9a-f]{32}$/', $info['md5_data_source'])) {
unset($info['md5_data_source']);
}
}
}

if (isset($info['flac']['STREAMINFO']['bits_per_sample'])) {
$info['audio']['bits_per_sample'] = $info['flac']['STREAMINFO']['bits_per_sample'];
if ($info['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
$this->warning('FLAC calculates MD5 data strangely on 8-bit audio, so the stored md5_data_source value will not match the decoded WAV file');
}
}

return true;
}


/**
* @param string $BlockData
*
* @return array
*/
public static function parseSTREAMINFOdata($BlockData) {
$streaminfo = array();
$streaminfo['min_block_size'] = getid3_lib::BigEndian2Int(substr($BlockData, 0, 2));
$streaminfo['max_block_size'] = getid3_lib::BigEndian2Int(substr($BlockData, 2, 2));
$streaminfo['min_frame_size'] = getid3_lib::BigEndian2Int(substr($BlockData, 4, 3));
$streaminfo['max_frame_size'] = getid3_lib::BigEndian2Int(substr($BlockData, 7, 3));

$SRCSBSS = getid3_lib::BigEndian2Bin(substr($BlockData, 10, 8));
$streaminfo['sample_rate'] = getid3_lib::Bin2Dec(substr($SRCSBSS, 0, 20));
$streaminfo['channels'] = getid3_lib::Bin2Dec(substr($SRCSBSS, 20, 3)) + 1;
$streaminfo['bits_per_sample'] = getid3_lib::Bin2Dec(substr($SRCSBSS, 23, 5)) + 1;
$streaminfo['samples_stream'] = getid3_lib::Bin2Dec(substr($SRCSBSS, 28, 36));

$streaminfo['audio_signature'] = substr($BlockData, 18, 16);

return $streaminfo;
}

/**
* @param string $BlockData
*
* @return bool
*/
private function parseSTREAMINFO($BlockData) {
$info = &$this->getid3->info;

$info['flac']['STREAMINFO'] = self::parseSTREAMINFOdata($BlockData);

if (!empty($info['flac']['STREAMINFO']['sample_rate'])) {

$info['audio']['bitrate_mode'] = 'vbr';
$info['audio']['sample_rate'] = $info['flac']['STREAMINFO']['sample_rate'];
$info['audio']['channels'] = $info['flac']['STREAMINFO']['channels'];
$info['audio']['bits_per_sample'] = $info['flac']['STREAMINFO']['bits_per_sample'];
$info['playtime_seconds'] = $info['flac']['STREAMINFO']['samples_stream'] / $info['flac']['STREAMINFO']['sample_rate'];
if ($info['playtime_seconds'] > 0) {
if (!$this->isDependencyFor('matroska')) {
$info['audio']['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
}
else {
$this->warning('Cannot determine audio bitrate because total stream size is unknown');
}
}

} else {
return $this->error('Corrupt METAdata block: STREAMINFO');
}

return true;
}

/**
* @param string $BlockData
*
* @return bool
*/
private function parseAPPLICATION($BlockData) {
$info = &$this->getid3->info;

$ApplicationID = getid3_lib::BigEndian2Int(substr($BlockData, 0, 4));
$info['flac']['APPLICATION'][$ApplicationID]['name'] = self::applicationIDLookup($ApplicationID);
$info['flac']['APPLICATION'][$ApplicationID]['data'] = substr($BlockData, 4);

return true;
}

/**
* @param string $BlockData
*
* @return bool
*/
private function parseSEEKTABLE($BlockData) {
$info = &$this->getid3->info;

$offset = 0;
$BlockLength = strlen($BlockData);
$placeholderpattern = str_repeat("\xFF", 8);
while ($offset < $BlockLength) {
$SampleNumberString = substr($BlockData, $offset, 8);
$offset += 8;
if ($SampleNumberString == $placeholderpattern) {

// placeholder point
getid3_lib::safe_inc($info['flac']['SEEKTABLE']['placeholders'], 1);
$offset += 10;

} else {

$SampleNumber = getid3_lib::BigEndian2Int($SampleNumberString);
$info['flac']['SEEKTABLE'][$SampleNumber]['offset'] = getid3_lib::BigEndian2Int(substr($BlockData, $offset, 8));
$offset += 8;
$info['flac']['SEEKTABLE'][$SampleNumber]['samples'] = getid3_lib::BigEndian2Int(substr($BlockData, $offset, 2));
$offset += 2;

}
}

return true;
}

/**
* @param string $BlockData
*
* @return bool
*/
private function parseVORBIS_COMMENT($BlockData) {
$info = &$this->getid3->info;

$getid3_ogg = new getid3_ogg($this->getid3);
if ($this->isDependencyFor('matroska')) {
$getid3_ogg->setStringMode($this->data_string);
}
$getid3_ogg->ParseVorbisComments();
if (isset($info['ogg'])) {
unset($info['ogg']['comments_raw']);
$info['flac']['VORBIS_COMMENT'] = $info['ogg'];
unset($info['ogg']);
}

unset($getid3_ogg);

return true;
}

/**
* @param string $BlockData
*
* @return bool
*/
private function parseCUESHEET($BlockData) {
$info = &$this->getid3->info;
$offset = 0;
$info['flac']['CUESHEET']['media_catalog_number'] = trim(substr($BlockData, $offset, 128), "\0");
$offset += 128;
$info['flac']['CUESHEET']['lead_in_samples'] = getid3_lib::BigEndian2Int(substr($BlockData, $offset, 8));
$offset += 8;
$info['flac']['CUESHEET']['flags']['is_cd'] = (bool) (getid3_lib::BigEndian2Int(substr($BlockData, $offset, 1)) & 0x80);
$offset += 1;

$offset += 258; // reserved

$info['flac']['CUESHEET']['number_tracks'] = getid3_lib::BigEndian2Int(substr($BlockData, $offset, 1));
$offset += 1;

for ($track = 0; $track < $info['flac']['CUESHEET']['number_tracks']; $track++) {
$TrackSampleOffset = getid3_lib::BigEndian2Int(substr($BlockData, $offset, 8));
$offset += 8;
$TrackNumber = getid3_lib::BigEndian2Int(substr($BlockData, $offset, 1));
$offset += 1;

$info['flac']['CUESHEET']['tracks'][$TrackNumber]['sample_offset'] = $TrackSampleOffset;

$info['flac']['CUESHEET']['tracks'][$TrackNumber]['isrc'] = substr($BlockData, $offset, 12);
$offset += 12;

$TrackFlagsRaw = getid3_lib::BigEndian2Int(substr($BlockData, $offset, 1));
$offset += 1;
$info['flac']['CUESHEET']['tracks'][$TrackNumber]['flags']['is_audio'] = (bool) ($TrackFlagsRaw & 0x80);
$info['flac']['CUESHEET']['tracks'][$TrackNumber]['flags']['pre_emphasis'] = (bool) ($TrackFlagsRaw & 0x40);

$offset += 13; // reserved

$info['flac']['CUESHEET']['tracks'][$TrackNumber]['index_points'] = getid3_lib::BigEndian2Int(substr($BlockData, $offset, 1));
$offset += 1;

for ($index = 0; $index < $info['flac']['CUESHEET']['tracks'][$TrackNumber]['index_points']; $index++) {
$IndexSampleOffset = getid3_lib::BigEndian2Int(substr($BlockData, $offset, 8));
$offset += 8;
$IndexNumber = getid3_lib::BigEndian2Int(substr($BlockData, $offset, 1));
$offset += 1;

$offset += 3; // reserved

$info['flac']['CUESHEET']['tracks'][$TrackNumber]['indexes'][$IndexNumber] = $IndexSampleOffset;
}
}

return true;
}

/**
* Parse METADATA_BLOCK_PICTURE flac structure and extract attachment
* External usage: audio.ogg
*
* @return bool
*/
public function parsePICTURE() {
$info = &$this->getid3->info;

$picture = array();
$picture['typeid'] = getid3_lib::BigEndian2Int($this->fread(4));
$picture['picturetype'] = self::pictureTypeLookup($picture['typeid']);
$picture['image_mime'] = $this->fread(getid3_lib::BigEndian2Int($this->fread(4)));
$descr_length = getid3_lib::BigEndian2Int($this->fread(4));
if ($descr_length) {
$picture['description'] = $this->fread($descr_length);
}
$picture['image_width'] = getid3_lib::BigEndian2Int($this->fread(4));
$picture['image_height'] = getid3_lib::BigEndian2Int($this->fread(4));
$picture['color_depth'] = getid3_lib::BigEndian2Int($this->fread(4));
$picture['colors_indexed'] = getid3_lib::BigEndian2Int($this->fread(4));
$picture['datalength'] = getid3_lib::BigEndian2Int($this->fread(4));

if ($picture['image_mime'] == '-->') {
$picture['data'] = $this->fread($picture['datalength']);
} else {
$picture['data'] = $this->saveAttachment(
str_replace('/', '_', $picture['picturetype']).'_'.$this->ftell(),
$this->ftell(),
$picture['datalength'],
$picture['image_mime']);
}

$info['flac']['PICTURE'][] = $picture;

return true;
}

/**
* @param int $blocktype
*
* @return string
*/
public static function metaBlockTypeLookup($blocktype) {
static $lookup = array(
0 => 'STREAMINFO',
1 => 'PADDING',
2 => 'APPLICATION',
3 => 'SEEKTABLE',
4 => 'VORBIS_COMMENT',
5 => 'CUESHEET',
6 => 'PICTURE',
);
return (isset($lookup[$blocktype]) ? $lookup[$blocktype] : 'reserved');
}

/**
* @param int $applicationid
*
* @return string
*/
public static function applicationIDLookup($applicationid) {
// http://flac.sourceforge.net/id.html
static $lookup = array(
0x41544348 => 'FlacFile', // "ATCH"
0x42534F4C => 'beSolo', // "BSOL"
0x42554753 => 'Bugs Player', // "BUGS"
0x43756573 => 'GoldWave cue points (specification)', // "Cues"
0x46696361 => 'CUE Splitter', // "Fica"
0x46746F6C => 'flac-tools', // "Ftol"
0x4D4F5442 => 'MOTB MetaCzar', // "MOTB"
0x4D505345 => 'MP3 Stream Editor', // "MPSE"
0x4D754D4C => 'MusicML: Music Metadata Language', // "MuML"
0x52494646 => 'Sound Devices RIFF chunk storage', // "RIFF"
0x5346464C => 'Sound Font FLAC', // "SFFL"
0x534F4E59 => 'Sony Creative Software', // "SONY"
0x5351455A => 'flacsqueeze', // "SQEZ"
0x54745776 => 'TwistedWave', // "TtWv"
0x55495453 => 'UITS Embedding tools', // "UITS"
0x61696666 => 'FLAC AIFF chunk storage', // "aiff"
0x696D6167 => 'flac-image application for storing arbitrary files in APPLICATION metadata blocks', // "imag"
0x7065656D => 'Parseable Embedded Extensible Metadata (specification)', // "peem"
0x71667374 => 'QFLAC Studio', // "qfst"
0x72696666 => 'FLAC RIFF chunk storage', // "riff"
0x74756E65 => 'TagTuner', // "tune"
0x78626174 => 'XBAT', // "xbat"
0x786D6364 => 'xmcd', // "xmcd"
);
return (isset($lookup[$applicationid]) ? $lookup[$applicationid] : 'reserved');
}

/**
* @param int $type_id
*
* @return string
*/
public static function pictureTypeLookup($type_id) {
static $lookup = array (
0 => 'Other',
1 => '32x32 pixels \'file icon\' (PNG only)',
2 => 'Other file icon',
3 => 'Cover (front)',
4 => 'Cover (back)',
5 => 'Leaflet page',
6 => 'Media (e.g. label side of CD)',
7 => 'Lead artist/lead performer/soloist',
8 => 'Artist/performer',
9 => 'Conductor',
10 => 'Band/Orchestra',
11 => 'Composer',
12 => 'Lyricist/text writer',
13 => 'Recording Location',
14 => 'During recording',
15 => 'During performance',
16 => 'Movie/video screen capture',
17 => 'A bright coloured fish',
18 => 'Illustration',
19 => 'Band/artist logotype',
20 => 'Publisher/Studio logotype',
);
return (isset($lookup[$type_id]) ? $lookup[$type_id] : 'reserved');
}

}