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


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';

    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();
    }

    public function 
parseMETAdata() {
        
$info = &$this->getid3->info;
        do {
            
$BlockOffset   $this->ftell();
            
$BlockHeader   $this->fread(4);
            
$LBFBT         getid3_lib::BigEndian2Int(substr($BlockHeader01));
            
$LastBlockFlag = (bool) ($LBFBT 0x80);
            
$BlockType     =        ($LBFBT 0x7F);
            
$BlockLength   getid3_lib::BigEndian2Int(substr($BlockHeader13));
            
$BlockTypeText self::metaBlockTypeLookup($BlockType);

            if ((
$BlockOffset $BlockLength) > $info['avdataend']) {
                
$this->error('METADATA_BLOCK_HEADER.BLOCK_TYPE ('.$BlockTypeText.') at offset '.$BlockOffset.' extends beyond end of file');
                break;
            }
            if (
$BlockLength 1) {
                
$this->error('METADATA_BLOCK_HEADER.BLOCK_LENGTH ('.$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;
    }

    private function 
parseSTREAMINFO($BlockData) {
        
$info = &$this->getid3->info;

        
$info['flac']['STREAMINFO'] = array();
        
$streaminfo = &$info['flac']['STREAMINFO'];

        
$streaminfo['min_block_size']  = getid3_lib::BigEndian2Int(substr($BlockData02));
        
$streaminfo['max_block_size']  = getid3_lib::BigEndian2Int(substr($BlockData22));
        
$streaminfo['min_frame_size']  = getid3_lib::BigEndian2Int(substr($BlockData43));
        
$streaminfo['max_frame_size']  = getid3_lib::BigEndian2Int(substr($BlockData73));

        
$SRCSBSS                       getid3_lib::BigEndian2Bin(substr($BlockData108));
        
$streaminfo['sample_rate']     = getid3_lib::Bin2Dec(substr($SRCSBSS,  020));
        
$streaminfo['channels']        = getid3_lib::Bin2Dec(substr($SRCSBSS20,  3)) + 1;
        
$streaminfo['bits_per_sample'] = getid3_lib::Bin2Dec(substr($SRCSBSS23,  5)) + 1;
        
$streaminfo['samples_stream']  = getid3_lib::Bin2Dec(substr($SRCSBSS2836));

        
$streaminfo['audio_signature'] = substr($BlockData1816);

        if (!empty(
$streaminfo['sample_rate'])) {

            
$info['audio']['bitrate_mode']    = 'vbr';
            
$info['audio']['sample_rate']     = $streaminfo['sample_rate'];
            
$info['audio']['channels']        = $streaminfo['channels'];
            
$info['audio']['bits_per_sample'] = $streaminfo['bits_per_sample'];
            
$info['playtime_seconds']         = $streaminfo['samples_stream'] / $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;
    }

    private function 
parseAPPLICATION($BlockData) {
        
$info = &$this->getid3->info;

        
$ApplicationID getid3_lib::BigEndian2Int(substr($BlockData04));
        
$info['flac']['APPLICATION'][$ApplicationID]['name'] = self::applicationIDLookup($ApplicationID);
        
$info['flac']['APPLICATION'][$ApplicationID]['data'] = substr($BlockData4);

        return 
true;
    }

    private function 
parseSEEKTABLE($BlockData) {
        
$info = &$this->getid3->info;

        
$offset 0;
        
$BlockLength strlen($BlockData);
        
$placeholderpattern str_repeat("\xFF"8);
        while (
$offset $BlockLength) {
            
$SampleNumberString substr($BlockData$offset8);
            
$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($BlockData$offset8));
                
$offset += 8;
                
$info['flac']['SEEKTABLE'][$SampleNumber]['samples'] = getid3_lib::BigEndian2Int(substr($BlockData$offset2));
                
$offset += 2;

            }
        }

        return 
true;
    }

    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;
    }

    private function 
parseCUESHEET($BlockData) {
        
$info = &$this->getid3->info;
        
$offset 0;
        
$info['flac']['CUESHEET']['media_catalog_number'] =                              trim(substr($BlockData$offset128), "\0");
        
$offset += 128;
        
$info['flac']['CUESHEET']['lead_in_samples']      =         getid3_lib::BigEndian2Int(substr($BlockData$offset8));
        
$offset += 8;
        
$info['flac']['CUESHEET']['flags']['is_cd']       = (bool) (getid3_lib::BigEndian2Int(substr($BlockData$offset1)) & 0x80);
        
$offset += 1;

        
$offset += 258// reserved

        
$info['flac']['CUESHEET']['number_tracks']        =         getid3_lib::BigEndian2Int(substr($BlockData$offset1));
        
$offset += 1;

        for (
$track 0$track $info['flac']['CUESHEET']['number_tracks']; $track++) {
            
$TrackSampleOffset getid3_lib::BigEndian2Int(substr($BlockData$offset8));
            
$offset += 8;
            
$TrackNumber       getid3_lib::BigEndian2Int(substr($BlockData$offset1));
            
$offset += 1;

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

            
$info['flac']['CUESHEET']['tracks'][$TrackNumber]['isrc']                  =                           substr($BlockData$offset12);
            
$offset += 12;

            
$TrackFlagsRaw                                                             getid3_lib::BigEndian2Int(substr($BlockData$offset1));
            
$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($BlockData$offset1));
            
$offset += 1;

            for (
$index 0$index $info['flac']['CUESHEET']['tracks'][$TrackNumber]['index_points']; $index++) {
                
$IndexSampleOffset getid3_lib::BigEndian2Int(substr($BlockData$offset8));
                
$offset += 8;
                
$IndexNumber       getid3_lib::BigEndian2Int(substr($BlockData$offset1));
                
$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
    */
    
public function parsePICTURE() {
        
$info = &$this->getid3->info;

        
$picture['typeid']         = getid3_lib::BigEndian2Int($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;
    }

    public static function 
metaBlockTypeLookup($blocktype) {
        static 
$lookup = array(
            
=> 'STREAMINFO',
            
=> 'PADDING',
            
=> 'APPLICATION',
            
=> 'SEEKTABLE',
            
=> 'VORBIS_COMMENT',
            
=> 'CUESHEET',
            
=> 'PICTURE',
        );
        return (isset(
$lookup[$blocktype]) ? $lookup[$blocktype] : 'reserved');
    }

    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');
    }

    public static function 
pictureTypeLookup($type_id) {
        static 
$lookup = array (
             
=> 'Other',
             
=> '32x32 pixels \'file icon\' (PNG only)',
             
=> 'Other file icon',
             
=> 'Cover (front)',
             
=> 'Cover (back)',
             
=> 'Leaflet page',
             
=> 'Media (e.g. label side of CD)',
             
=> 'Lead artist/lead performer/soloist',
             
=> 'Artist/performer',
             
=> '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');
    }

}