<?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.dts.php                                        //
// module for analyzing DTS Audio files                        //
// dependencies: NONE                                          //
//                                                             //
/////////////////////////////////////////////////////////////////


/**
* @tutorial http://wiki.multimedia.cx/index.php?title=DTS
*/
class getid3_dts extends getid3_handler
{
    
/**
    * Default DTS syncword used in native .cpt or .dts formats
    */
    
const syncword "\x7F\xFE\x80\x01";

    private 
$readBinDataOffset 0;

    
/**
    * Possible syncwords indicating bitstream encoding
    */
    
public static $syncwords = array(
        
=> "\x7F\xFE\x80\x01",  // raw big-endian
        
=> "\xFE\x7F\x01\x80",  // raw little-endian
        
=> "\x1F\xFF\xE8\x00",  // 14-bit big-endian
        
=> "\xFF\x1F\x00\xE8"); // 14-bit little-endian

    
public function Analyze() {
        
$info = &$this->getid3->info;
        
$info['fileformat'] = 'dts';

        
$this->fseek($info['avdataoffset']);
        
$DTSheader $this->fread(20); // we only need 2 words magic + 6 words frame header, but these words may be normal 16-bit words OR 14-bit words with 2 highest bits set to zero, so 8 words can be either 8*16/8 = 16 bytes OR 8*16*(16/14)/8 = 18.3 bytes

        // check syncword
        
$sync substr($DTSheader04);
        if ((
$encoding array_search($syncself::$syncwords)) !== false) {

            
$info['dts']['raw']['magic'] = $sync;
            
$this->readBinDataOffset 32;

        } elseif (
$this->isDependencyFor('matroska')) {

            
// Matroska contains DTS without syncword encoded as raw big-endian format
            
$encoding 0;
            
$this->readBinDataOffset 0;

        } else {

            unset(
$info['fileformat']);
            return 
$this->error('Expecting "'.implode('| 'array_map('getid3_lib::PrintHexBytes'self::$syncwords)).'" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes($sync).'"');

        }

        
// decode header
        
$fhBS '';
        for (
$word_offset 0$word_offset <= strlen($DTSheader); $word_offset += 2) {
            switch (
$encoding) {
                case 
0// raw big-endian
                    
$fhBS .=        getid3_lib::BigEndian2Bin(       substr($DTSheader$word_offset2) );
                    break;
                case 
1// raw little-endian
                    
$fhBS .=        getid3_lib::BigEndian2Bin(strrev(substr($DTSheader$word_offset2)));
                    break;
                case 
2// 14-bit big-endian
                    
$fhBS .= substr(getid3_lib::BigEndian2Bin(       substr($DTSheader$word_offset2) ), 214);
                    break;
                case 
3// 14-bit little-endian
                    
$fhBS .= substr(getid3_lib::BigEndian2Bin(strrev(substr($DTSheader$word_offset2))), 214);
                    break;
            }
        }

        
$info['dts']['raw']['frame_type']             =        $this->readBinData($fhBS,  1);
        
$info['dts']['raw']['deficit_samples']        =        $this->readBinData($fhBS,  5);
        
$info['dts']['flags']['crc_present']          = (bool) $this->readBinData($fhBS,  1);
        
$info['dts']['raw']['pcm_sample_blocks']      =        $this->readBinData($fhBS,  7);
        
$info['dts']['raw']['frame_byte_size']        =        $this->readBinData($fhBS14);
        
$info['dts']['raw']['channel_arrangement']    =        $this->readBinData($fhBS,  6);
        
$info['dts']['raw']['sample_frequency']       =        $this->readBinData($fhBS,  4);
        
$info['dts']['raw']['bitrate']                =        $this->readBinData($fhBS,  5);
        
$info['dts']['flags']['embedded_downmix']     = (bool) $this->readBinData($fhBS,  1);
        
$info['dts']['flags']['dynamicrange']         = (bool) $this->readBinData($fhBS,  1);
        
$info['dts']['flags']['timestamp']            = (bool) $this->readBinData($fhBS,  1);
        
$info['dts']['flags']['auxdata']              = (bool) $this->readBinData($fhBS,  1);
        
$info['dts']['flags']['hdcd']                 = (bool) $this->readBinData($fhBS,  1);
        
$info['dts']['raw']['extension_audio']        =        $this->readBinData($fhBS,  3);
        
$info['dts']['flags']['extended_coding']      = (bool) $this->readBinData($fhBS,  1);
        
$info['dts']['flags']['audio_sync_insertion'] = (bool) $this->readBinData($fhBS,  1);
        
$info['dts']['raw']['lfe_effects']            =        $this->readBinData($fhBS,  2);
        
$info['dts']['flags']['predictor_history']    = (bool) $this->readBinData($fhBS,  1);
        if (
$info['dts']['flags']['crc_present']) {
            
$info['dts']['raw']['crc16']              =        $this->readBinData($fhBS16);
        }
        
$info['dts']['flags']['mri_perfect_reconst']  = (bool) $this->readBinData($fhBS,  1);
        
$info['dts']['raw']['encoder_soft_version']   =        $this->readBinData($fhBS,  4);
        
$info['dts']['raw']['copy_history']           =        $this->readBinData($fhBS,  2);
        
$info['dts']['raw']['bits_per_sample']        =        $this->readBinData($fhBS,  2);
        
$info['dts']['flags']['surround_es']          = (bool) $this->readBinData($fhBS,  1);
        
$info['dts']['flags']['front_sum_diff']       = (bool) $this->readBinData($fhBS,  1);
        
$info['dts']['flags']['surround_sum_diff']    = (bool) $this->readBinData($fhBS,  1);
        
$info['dts']['raw']['dialog_normalization']   =        $this->readBinData($fhBS,  4);


        
$info['dts']['bitrate']              = self::bitrateLookup($info['dts']['raw']['bitrate']);
        
$info['dts']['bits_per_sample']      = self::bitPerSampleLookup($info['dts']['raw']['bits_per_sample']);
        
$info['dts']['sample_rate']          = self::sampleRateLookup($info['dts']['raw']['sample_frequency']);
        
$info['dts']['dialog_normalization'] = self::dialogNormalization($info['dts']['raw']['dialog_normalization'], $info['dts']['raw']['encoder_soft_version']);
        
$info['dts']['flags']['lossless']    = (($info['dts']['raw']['bitrate'] == 31) ? true  false);
        
$info['dts']['bitrate_mode']         = (($info['dts']['raw']['bitrate'] == 30) ? 'vbr' 'cbr');
        
$info['dts']['channels']             = self::numChannelsLookup($info['dts']['raw']['channel_arrangement']);
        
$info['dts']['channel_arrangement']  = self::channelArrangementLookup($info['dts']['raw']['channel_arrangement']);

        
$info['audio']['dataformat']          = 'dts';
        
$info['audio']['lossless']            = $info['dts']['flags']['lossless'];
        
$info['audio']['bitrate_mode']        = $info['dts']['bitrate_mode'];
        
$info['audio']['bits_per_sample']     = $info['dts']['bits_per_sample'];
        
$info['audio']['sample_rate']         = $info['dts']['sample_rate'];
        
$info['audio']['channels']            = $info['dts']['channels'];
        
$info['audio']['bitrate']             = $info['dts']['bitrate'];
        if (isset(
$info['avdataend']) && !empty($info['dts']['bitrate']) && is_numeric($info['dts']['bitrate'])) {
            
$info['playtime_seconds']         = ($info['avdataend'] - $info['avdataoffset']) / ($info['dts']['bitrate'] / 8);
            if ((
$encoding == 2) || ($encoding == 3)) {
                
// 14-bit data packed into 16-bit words, so the playtime is wrong because only (14/16) of the bytes in the data portion of the file are used at the specified bitrate
                
$info['playtime_seconds'] *= (14 16);
            }
        }
        return 
true;
    }

    private function 
readBinData($bin$length) {
        
$data substr($bin$this->readBinDataOffset$length);
        
$this->readBinDataOffset += $length;

        return 
bindec($data);
    }

    public static function 
bitrateLookup($index) {
        static 
$lookup = array(
            
0  => 32000,
            
1  => 56000,
            
2  => 64000,
            
3  => 96000,
            
4  => 112000,
            
5  => 128000,
            
6  => 192000,
            
7  => 224000,
            
8  => 256000,
            
9  => 320000,
            
10 => 384000,
            
11 => 448000,
            
12 => 512000,
            
13 => 576000,
            
14 => 640000,
            
15 => 768000,
            
16 => 960000,
            
17 => 1024000,
            
18 => 1152000,
            
19 => 1280000,
            
20 => 1344000,
            
21 => 1408000,
            
22 => 1411200,
            
23 => 1472000,
            
24 => 1536000,
            
25 => 1920000,
            
26 => 2048000,
            
27 => 3072000,
            
28 => 3840000,
            
29 => 'open',
            
30 => 'variable',
            
31 => 'lossless',
        );
        return (isset(
$lookup[$index]) ? $lookup[$index] : false);
    }

    public static function 
sampleRateLookup($index) {
        static 
$lookup = array(
            
0  => 'invalid',
            
1  => 8000,
            
2  => 16000,
            
3  => 32000,
            
4  => 'invalid',
            
5  => 'invalid',
            
6  => 11025,
            
7  => 22050,
            
8  => 44100,
            
9  => 'invalid',
            
10 => 'invalid',
            
11 => 12000,
            
12 => 24000,
            
13 => 48000,
            
14 => 'invalid',
            
15 => 'invalid',
        );
        return (isset(
$lookup[$index]) ? $lookup[$index] : false);
    }

    public static function 
bitPerSampleLookup($index) {
        static 
$lookup = array(
            
0  => 16,
            
1  => 20,
            
2  => 24,
            
3  => 24,
        );
        return (isset(
$lookup[$index]) ? $lookup[$index] : false);
    }

    public static function 
numChannelsLookup($index) {
        switch (
$index) {
            case 
0:
                return 
1;
                break;
            case 
1:
            case 
2:
            case 
3:
            case 
4:
                return 
2;
                break;
            case 
5:
            case 
6:
                return 
3;
                break;
            case 
7:
            case 
8:
                return 
4;
                break;
            case 
9:
                return 
5;
                break;
            case 
10:
            case 
11:
            case 
12:
                return 
6;
                break;
            case 
13:
                return 
7;
                break;
            case 
14:
            case 
15:
                return 
8;
                break;
        }
        return 
false;
    }

    public static function 
channelArrangementLookup($index) {
        static 
$lookup = array(
            
0  => 'A',
            
1  => 'A + B (dual mono)',
            
2  => 'L + R (stereo)',
            
3  => '(L+R) + (L-R) (sum-difference)',
            
4  => 'LT + RT (left and right total)',
            
5  => 'C + L + R',
            
6  => 'L + R + S',
            
7  => 'C + L + R + S',
            
8  => 'L + R + SL + SR',
            
9  => 'C + L + R + SL + SR',
            
10 => 'CL + CR + L + R + SL + SR',
            
11 => 'C + L + R+ LR + RR + OV',
            
12 => 'CF + CR + LF + RF + LR + RR',
            
13 => 'CL + C + CR + L + R + SL + SR',
            
14 => 'CL + CR + L + R + SL1 + SL2 + SR1 + SR2',
            
15 => 'CL + C+ CR + L + R + SL + S + SR',
        );
        return (isset(
$lookup[$index]) ? $lookup[$index] : 'user-defined');
    }

    public static function 
dialogNormalization($index$version) {
        switch (
$version) {
            case 
7:
                return 
$index;
                break;
            case 
6:
                return 
16 $index;
                break;
        }
        return 
false;
    }

}