1<?php
2
3/////////////////////////////////////////////////////////////////
4/// getID3() by James Heinrich <info@getid3.org>               //
5//  available at https://github.com/JamesHeinrich/getID3       //
6//            or https://www.getid3.org                        //
7//            or http://getid3.sourceforge.net                 //
8//  see readme.txt for more details                            //
9/////////////////////////////////////////////////////////////////
10//                                                             //
11// module.audio.dts.php                                        //
12// module for analyzing DTS Audio files                        //
13// dependencies: NONE                                          //
14//                                                             //
15/////////////////////////////////////////////////////////////////
16
17if (!defined('GETID3_INCLUDEPATH')) { // prevent path-exposing attacks that access modules directly on public webservers
18	exit;
19}
20
21/**
22* @tutorial http://wiki.multimedia.cx/index.php?title=DTS
23*/
24class getid3_dts extends getid3_handler
25{
26	/**
27	 * Default DTS syncword used in native .cpt or .dts formats.
28	 */
29	const syncword = "\x7F\xFE\x80\x01";
30
31	/**
32	 * @var int
33	 */
34	private $readBinDataOffset = 0;
35
36	/**
37	 * Possible syncwords indicating bitstream encoding.
38	 */
39	public static $syncwords = array(
40		0 => "\x7F\xFE\x80\x01",  // raw big-endian
41		1 => "\xFE\x7F\x01\x80",  // raw little-endian
42		2 => "\x1F\xFF\xE8\x00",  // 14-bit big-endian
43		3 => "\xFF\x1F\x00\xE8"); // 14-bit little-endian
44
45	/**
46	 * @return bool
47	 */
48	public function Analyze() {
49		$info = &$this->getid3->info;
50		$info['fileformat'] = 'dts';
51
52		$this->fseek($info['avdataoffset']);
53		$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
54
55		// check syncword
56		$sync = substr($DTSheader, 0, 4);
57		if (($encoding = array_search($sync, self::$syncwords)) !== false) {
58
59			$info['dts']['raw']['magic'] = $sync;
60			$this->readBinDataOffset = 32;
61
62		} elseif ($this->isDependencyFor('matroska')) {
63
64			// Matroska contains DTS without syncword encoded as raw big-endian format
65			$encoding = 0;
66			$this->readBinDataOffset = 0;
67
68		} else {
69
70			unset($info['fileformat']);
71			return $this->error('Expecting "'.implode('| ', array_map('getid3_lib::PrintHexBytes', self::$syncwords)).'" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes($sync).'"');
72
73		}
74
75		// decode header
76		$fhBS = '';
77		for ($word_offset = 0; $word_offset <= strlen($DTSheader); $word_offset += 2) {
78			switch ($encoding) {
79				case 0: // raw big-endian
80					$fhBS .=        getid3_lib::BigEndian2Bin(       substr($DTSheader, $word_offset, 2) );
81					break;
82				case 1: // raw little-endian
83					$fhBS .=        getid3_lib::BigEndian2Bin(strrev(substr($DTSheader, $word_offset, 2)));
84					break;
85				case 2: // 14-bit big-endian
86					$fhBS .= substr(getid3_lib::BigEndian2Bin(       substr($DTSheader, $word_offset, 2) ), 2, 14);
87					break;
88				case 3: // 14-bit little-endian
89					$fhBS .= substr(getid3_lib::BigEndian2Bin(strrev(substr($DTSheader, $word_offset, 2))), 2, 14);
90					break;
91			}
92		}
93
94		$info['dts']['raw']['frame_type']             =        $this->readBinData($fhBS,  1);
95		$info['dts']['raw']['deficit_samples']        =        $this->readBinData($fhBS,  5);
96		$info['dts']['flags']['crc_present']          = (bool) $this->readBinData($fhBS,  1);
97		$info['dts']['raw']['pcm_sample_blocks']      =        $this->readBinData($fhBS,  7);
98		$info['dts']['raw']['frame_byte_size']        =        $this->readBinData($fhBS, 14);
99		$info['dts']['raw']['channel_arrangement']    =        $this->readBinData($fhBS,  6);
100		$info['dts']['raw']['sample_frequency']       =        $this->readBinData($fhBS,  4);
101		$info['dts']['raw']['bitrate']                =        $this->readBinData($fhBS,  5);
102		$info['dts']['flags']['embedded_downmix']     = (bool) $this->readBinData($fhBS,  1);
103		$info['dts']['flags']['dynamicrange']         = (bool) $this->readBinData($fhBS,  1);
104		$info['dts']['flags']['timestamp']            = (bool) $this->readBinData($fhBS,  1);
105		$info['dts']['flags']['auxdata']              = (bool) $this->readBinData($fhBS,  1);
106		$info['dts']['flags']['hdcd']                 = (bool) $this->readBinData($fhBS,  1);
107		$info['dts']['raw']['extension_audio']        =        $this->readBinData($fhBS,  3);
108		$info['dts']['flags']['extended_coding']      = (bool) $this->readBinData($fhBS,  1);
109		$info['dts']['flags']['audio_sync_insertion'] = (bool) $this->readBinData($fhBS,  1);
110		$info['dts']['raw']['lfe_effects']            =        $this->readBinData($fhBS,  2);
111		$info['dts']['flags']['predictor_history']    = (bool) $this->readBinData($fhBS,  1);
112		if ($info['dts']['flags']['crc_present']) {
113			$info['dts']['raw']['crc16']              =        $this->readBinData($fhBS, 16);
114		}
115		$info['dts']['flags']['mri_perfect_reconst']  = (bool) $this->readBinData($fhBS,  1);
116		$info['dts']['raw']['encoder_soft_version']   =        $this->readBinData($fhBS,  4);
117		$info['dts']['raw']['copy_history']           =        $this->readBinData($fhBS,  2);
118		$info['dts']['raw']['bits_per_sample']        =        $this->readBinData($fhBS,  2);
119		$info['dts']['flags']['surround_es']          = (bool) $this->readBinData($fhBS,  1);
120		$info['dts']['flags']['front_sum_diff']       = (bool) $this->readBinData($fhBS,  1);
121		$info['dts']['flags']['surround_sum_diff']    = (bool) $this->readBinData($fhBS,  1);
122		$info['dts']['raw']['dialog_normalization']   =        $this->readBinData($fhBS,  4);
123
124
125		$info['dts']['bitrate']              = self::bitrateLookup($info['dts']['raw']['bitrate']);
126		$info['dts']['bits_per_sample']      = self::bitPerSampleLookup($info['dts']['raw']['bits_per_sample']);
127		$info['dts']['sample_rate']          = self::sampleRateLookup($info['dts']['raw']['sample_frequency']);
128		$info['dts']['dialog_normalization'] = self::dialogNormalization($info['dts']['raw']['dialog_normalization'], $info['dts']['raw']['encoder_soft_version']);
129		$info['dts']['flags']['lossless']    = (($info['dts']['raw']['bitrate'] == 31) ? true  : false);
130		$info['dts']['bitrate_mode']         = (($info['dts']['raw']['bitrate'] == 30) ? 'vbr' : 'cbr');
131		$info['dts']['channels']             = self::numChannelsLookup($info['dts']['raw']['channel_arrangement']);
132		$info['dts']['channel_arrangement']  = self::channelArrangementLookup($info['dts']['raw']['channel_arrangement']);
133
134		$info['audio']['dataformat']          = 'dts';
135		$info['audio']['lossless']            = $info['dts']['flags']['lossless'];
136		$info['audio']['bitrate_mode']        = $info['dts']['bitrate_mode'];
137		$info['audio']['bits_per_sample']     = $info['dts']['bits_per_sample'];
138		$info['audio']['sample_rate']         = $info['dts']['sample_rate'];
139		$info['audio']['channels']            = $info['dts']['channels'];
140		$info['audio']['bitrate']             = $info['dts']['bitrate'];
141		if (isset($info['avdataend']) && !empty($info['dts']['bitrate']) && is_numeric($info['dts']['bitrate'])) {
142			$info['playtime_seconds']         = ($info['avdataend'] - $info['avdataoffset']) / ($info['dts']['bitrate'] / 8);
143			if (($encoding == 2) || ($encoding == 3)) {
144				// 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
145				$info['playtime_seconds'] *= (14 / 16);
146			}
147		}
148		return true;
149	}
150
151	/**
152	 * @param string $bin
153	 * @param int $length
154	 *
155	 * @return int
156	 */
157	private function readBinData($bin, $length) {
158		$data = substr($bin, $this->readBinDataOffset, $length);
159		$this->readBinDataOffset += $length;
160
161		return bindec($data);
162	}
163
164	/**
165	 * @param int $index
166	 *
167	 * @return int|string|false
168	 */
169	public static function bitrateLookup($index) {
170		static $lookup = array(
171			0  => 32000,
172			1  => 56000,
173			2  => 64000,
174			3  => 96000,
175			4  => 112000,
176			5  => 128000,
177			6  => 192000,
178			7  => 224000,
179			8  => 256000,
180			9  => 320000,
181			10 => 384000,
182			11 => 448000,
183			12 => 512000,
184			13 => 576000,
185			14 => 640000,
186			15 => 768000,
187			16 => 960000,
188			17 => 1024000,
189			18 => 1152000,
190			19 => 1280000,
191			20 => 1344000,
192			21 => 1408000,
193			22 => 1411200,
194			23 => 1472000,
195			24 => 1536000,
196			25 => 1920000,
197			26 => 2048000,
198			27 => 3072000,
199			28 => 3840000,
200			29 => 'open',
201			30 => 'variable',
202			31 => 'lossless',
203		);
204		return (isset($lookup[$index]) ? $lookup[$index] : false);
205	}
206
207	/**
208	 * @param int $index
209	 *
210	 * @return int|string|false
211	 */
212	public static function sampleRateLookup($index) {
213		static $lookup = array(
214			0  => 'invalid',
215			1  => 8000,
216			2  => 16000,
217			3  => 32000,
218			4  => 'invalid',
219			5  => 'invalid',
220			6  => 11025,
221			7  => 22050,
222			8  => 44100,
223			9  => 'invalid',
224			10 => 'invalid',
225			11 => 12000,
226			12 => 24000,
227			13 => 48000,
228			14 => 'invalid',
229			15 => 'invalid',
230		);
231		return (isset($lookup[$index]) ? $lookup[$index] : false);
232	}
233
234	/**
235	 * @param int $index
236	 *
237	 * @return int|false
238	 */
239	public static function bitPerSampleLookup($index) {
240		static $lookup = array(
241			0  => 16,
242			1  => 20,
243			2  => 24,
244			3  => 24,
245		);
246		return (isset($lookup[$index]) ? $lookup[$index] : false);
247	}
248
249	/**
250	 * @param int $index
251	 *
252	 * @return int|false
253	 */
254	public static function numChannelsLookup($index) {
255		switch ($index) {
256			case 0:
257				return 1;
258			case 1:
259			case 2:
260			case 3:
261			case 4:
262				return 2;
263			case 5:
264			case 6:
265				return 3;
266			case 7:
267			case 8:
268				return 4;
269			case 9:
270				return 5;
271			case 10:
272			case 11:
273			case 12:
274				return 6;
275			case 13:
276				return 7;
277			case 14:
278			case 15:
279				return 8;
280		}
281		return false;
282	}
283
284	/**
285	 * @param int $index
286	 *
287	 * @return string
288	 */
289	public static function channelArrangementLookup($index) {
290		static $lookup = array(
291			0  => 'A',
292			1  => 'A + B (dual mono)',
293			2  => 'L + R (stereo)',
294			3  => '(L+R) + (L-R) (sum-difference)',
295			4  => 'LT + RT (left and right total)',
296			5  => 'C + L + R',
297			6  => 'L + R + S',
298			7  => 'C + L + R + S',
299			8  => 'L + R + SL + SR',
300			9  => 'C + L + R + SL + SR',
301			10 => 'CL + CR + L + R + SL + SR',
302			11 => 'C + L + R+ LR + RR + OV',
303			12 => 'CF + CR + LF + RF + LR + RR',
304			13 => 'CL + C + CR + L + R + SL + SR',
305			14 => 'CL + CR + L + R + SL1 + SL2 + SR1 + SR2',
306			15 => 'CL + C+ CR + L + R + SL + S + SR',
307		);
308		return (isset($lookup[$index]) ? $lookup[$index] : 'user-defined');
309	}
310
311	/**
312	 * @param int $index
313	 * @param int $version
314	 *
315	 * @return int|false
316	 */
317	public static function dialogNormalization($index, $version) {
318		switch ($version) {
319			case 7:
320				return 0 - $index;
321			case 6:
322				return 0 - 16 - $index;
323		}
324		return false;
325	}
326
327}
328