ILIAS  release_5-2 Revision v5.2.25-18-g3f80b828510
Public Member Functions | Static Public Member Functions
GetId3\Module\Audio\Aac Class Reference

GetId3() by James Heinrich info@.nosp@m.geti.nosp@m.d3.or.nosp@m.g //. More...

+ Inheritance diagram for GetId3\Module\Audio\Aac:
+ Collaboration diagram for GetId3\Module\Audio\Aac:

Public Member Functions

 analyze ()
 
 getAACADIFheaderFilepointer ()
 
 getAACADTSheaderFilepointer ($MaxFramesToScan=1000000, $ReturnExtendedInfo=false)
 array $decbin More...
 
- Public Member Functions inherited from GetId3\Handler\BaseHandler
 __construct (GetId3Core $getid3, $call_module=null)
 
 analyze ()
 Analyze from file pointer. More...
 
 AnalyzeString (&$string)
 Analyze from string instead. More...
 
 saveAttachment (&$ThisFileInfoIndex, $filename, $offset, $length)
 

Static Public Member Functions

static AACsampleRateLookup ($samplerateid)
 array $AACsampleRateLookup More...
 
static AACprofileLookup ($profileid, $mpegversion)
 array $AACprofileLookup More...
 
static AACchannelCountCalculate ($program_configs)
 

Additional Inherited Members

- Protected Member Functions inherited from GetId3\Handler\BaseHandler
 ftell ()
 
 fread ($bytes)
 
 fseek ($bytes, $whence=SEEK_SET)
 
 feof ()
 
 isDependencyFor ($module)
 
 error ($text)
 
 warning ($text)
 
- Protected Attributes inherited from GetId3\Handler\BaseHandler
 $getid3
 
 $data_string_flag = false
 
 $data_string = ''
 
 $data_string_position = 0
 
 $data_string_length = 0
 

Detailed Description

GetId3() by James Heinrich info@.nosp@m.geti.nosp@m.d3.or.nosp@m.g //.

module for analyzing AAC Audio files

Author
James Heinrich info@.nosp@m.geti.nosp@m.d3.or.nosp@m.g http://www.getid3.org

Definition at line 29 of file Aac.php.

Member Function Documentation

◆ AACchannelCountCalculate()

static GetId3\Module\Audio\Aac::AACchannelCountCalculate (   $program_configs)
static
Parameters
type$program_configs
Returns
int

Definition at line 536 of file Aac.php.

537  {
538  $channels = 0;
539  for ($i = 0; $i < $program_configs['num_front_channel_elements']; $i++) {
540  $channels++;
541  if ($program_configs['front_element_is_cpe'][$i]) {
542  // each front element is channel pair (CPE = Channel Pair Element)
543  $channels++;
544  }
545  }
546  for ($i = 0; $i < $program_configs['num_side_channel_elements']; $i++) {
547  $channels++;
548  if ($program_configs['side_element_is_cpe'][$i]) {
549  // each side element is channel pair (CPE = Channel Pair Element)
550  $channels++;
551  }
552  }
553  for ($i = 0; $i < $program_configs['num_back_channel_elements']; $i++) {
554  $channels++;
555  if ($program_configs['back_element_is_cpe'][$i]) {
556  // each back element is channel pair (CPE = Channel Pair Element)
557  $channels++;
558  }
559  }
560  for ($i = 0; $i < $program_configs['num_lfe_channel_elements']; $i++) {
561  $channels++;
562  }
563 
564  return $channels;
565  }

◆ AACprofileLookup()

static GetId3\Module\Audio\Aac::AACprofileLookup (   $profileid,
  $mpegversion 
)
static

array $AACprofileLookup

Parameters
type$profileid
type$mpegversion
Returns
type

Definition at line 514 of file Aac.php.

References array.

515  {
516  static $AACprofileLookup = array();
517  if (empty($AACprofileLookup)) {
518  $AACprofileLookup[2][0] = 'Main profile';
519  $AACprofileLookup[2][1] = 'Low Complexity profile (LC)';
520  $AACprofileLookup[2][2] = 'Scalable Sample Rate profile (SSR)';
521  $AACprofileLookup[2][3] = '(reserved)';
522  $AACprofileLookup[4][0] = 'AAC_MAIN';
523  $AACprofileLookup[4][1] = 'AAC_LC';
524  $AACprofileLookup[4][2] = 'AAC_SSR';
525  $AACprofileLookup[4][3] = 'AAC_LTP';
526  }
527 
528  return (isset($AACprofileLookup[$mpegversion][$profileid]) ? $AACprofileLookup[$mpegversion][$profileid] : 'invalid');
529  }
array
Create styles array
The data for the language used.
Definition: 40duplicateStyle.php:19

◆ AACsampleRateLookup()

static GetId3\Module\Audio\Aac::AACsampleRateLookup (   $samplerateid)
static

array $AACsampleRateLookup

Parameters
type$samplerateid
Returns
type

Definition at line 482 of file Aac.php.

References array.

483  {
484  static $AACsampleRateLookup = array();
485  if (empty($AACsampleRateLookup)) {
486  $AACsampleRateLookup[0] = 96000;
487  $AACsampleRateLookup[1] = 88200;
488  $AACsampleRateLookup[2] = 64000;
489  $AACsampleRateLookup[3] = 48000;
490  $AACsampleRateLookup[4] = 44100;
491  $AACsampleRateLookup[5] = 32000;
492  $AACsampleRateLookup[6] = 24000;
493  $AACsampleRateLookup[7] = 22050;
494  $AACsampleRateLookup[8] = 16000;
495  $AACsampleRateLookup[9] = 12000;
496  $AACsampleRateLookup[10] = 11025;
497  $AACsampleRateLookup[11] = 8000;
498  $AACsampleRateLookup[12] = 0;
499  $AACsampleRateLookup[13] = 0;
500  $AACsampleRateLookup[14] = 0;
501  $AACsampleRateLookup[15] = 0;
502  }
503 
504  return (isset($AACsampleRateLookup[$samplerateid]) ? $AACsampleRateLookup[$samplerateid] : 'invalid');
505  }
array
Create styles array
The data for the language used.
Definition: 40duplicateStyle.php:19

◆ analyze()

GetId3\Module\Audio\Aac::analyze ( )
Returns
boolean

Definition at line 35 of file Aac.php.

References $info, GetId3\Handler\BaseHandler\fread(), GetId3\Handler\BaseHandler\fseek(), GetId3\Module\Audio\Aac\getAACADIFheaderFilepointer(), and GetId3\Module\Audio\Aac\getAACADTSheaderFilepointer().

36  {
37  $info = &$this->getid3->info;
38  fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
39  if (fread($this->getid3->fp, 4) == 'ADIF') {
40  $this->getAACADIFheaderFilepointer();
41  } else {
42  $this->getAACADTSheaderFilepointer();
43  }
44 
45  return true;
46  }
GetId3\Module\Audio\Aac\getAACADIFheaderFilepointer
getAACADIFheaderFilepointer()
Definition: Aac.php:52
GetId3\Module\Audio\Aac\getAACADTSheaderFilepointer
getAACADTSheaderFilepointer($MaxFramesToScan=1000000, $ReturnExtendedInfo=false)
array $decbin
Definition: Aac.php:286
GetId3\Handler\BaseHandler\fseek
fseek($bytes, $whence=SEEK_SET)
Definition: BaseHandler.php:148
$info
$info
Definition: example_052.php:80
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◆ getAACADIFheaderFilepointer()

GetId3\Module\Audio\Aac::getAACADIFheaderFilepointer ( )
Returns
boolean

Definition at line 52 of file Aac.php.

References $info, GetId3\Lib\Helper\BigEndian2Bin(), GetId3\Lib\Helper\Bin2Dec(), GetId3\Lib\Helper\Bin2String(), GetId3\Handler\BaseHandler\fread(), and GetId3\Handler\BaseHandler\fseek().

Referenced by GetId3\Module\Audio\Aac\analyze().

53  {
54  $info = &$this->getid3->info;
55  $info['fileformat'] = 'aac';
56  $info['audio']['dataformat'] = 'aac';
57  $info['audio']['lossless'] = false;
58 
59  fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
60  $AACheader = fread($this->getid3->fp, 1024);
61  $offset = 0;
62 
63  if (substr($AACheader, 0, 4) == 'ADIF') {
64 
65  // http://faac.sourceforge.net/wiki/index.php?page=ADIF
66 
67  // http://libmpeg.org/mpeg4/doc/w2203tfs.pdf
68  // adif_header() {
69  // adif_id 32
70  // copyright_id_present 1
71  // if( copyright_id_present )
72  // copyright_id 72
73  // original_copy 1
74  // home 1
75  // bitstream_type 1
76  // bitrate 23
77  // num_program_config_elements 4
78  // for (i = 0; i < num_program_config_elements + 1; i++) {
79  // if( bitstream_type == '0' )
80  // adif_buffer_fullness 20
81  // program_config_element()
82  // }
83  // }
84 
85  $AACheaderBitstream = Helper::BigEndian2Bin($AACheader);
86  $bitoffset = 0;
87 
88  $info['aac']['header_type'] = 'ADIF';
89  $bitoffset += 32;
90  $info['aac']['header']['mpeg_version'] = 4;
91 
92  $info['aac']['header']['copyright'] = (bool) (substr($AACheaderBitstream, $bitoffset, 1) == '1');
93  $bitoffset += 1;
94  if ($info['aac']['header']['copyright']) {
95  $info['aac']['header']['copyright_id'] = Helper::Bin2String(substr($AACheaderBitstream, $bitoffset, 72));
96  $bitoffset += 72;
97  }
98  $info['aac']['header']['original_copy'] = (bool) (substr($AACheaderBitstream, $bitoffset, 1) == '1');
99  $bitoffset += 1;
100  $info['aac']['header']['home'] = (bool) (substr($AACheaderBitstream, $bitoffset, 1) == '1');
101  $bitoffset += 1;
102  $info['aac']['header']['is_vbr'] = (bool) (substr($AACheaderBitstream, $bitoffset, 1) == '1');
103  $bitoffset += 1;
104  if ($info['aac']['header']['is_vbr']) {
105  $info['audio']['bitrate_mode'] = 'vbr';
106  $info['aac']['header']['bitrate_max'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 23));
107  $bitoffset += 23;
108  } else {
109  $info['audio']['bitrate_mode'] = 'cbr';
110  $info['aac']['header']['bitrate'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 23));
111  $bitoffset += 23;
112  $info['audio']['bitrate'] = $info['aac']['header']['bitrate'];
113  }
114  if ($info['audio']['bitrate'] == 0) {
115  $info['error'][] = 'Corrupt AAC file: bitrate_audio == zero';
116 
117  return false;
118  }
119  $info['aac']['header']['num_program_configs'] = 1 + Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
120  $bitoffset += 4;
121 
122  for ($i = 0; $i < $info['aac']['header']['num_program_configs']; $i++) {
123  // http://www.audiocoding.com/wiki/index.php?page=program_config_element
124 
125  // buffer_fullness 20
126 
127  // element_instance_tag 4
128  // object_type 2
129  // sampling_frequency_index 4
130  // num_front_channel_elements 4
131  // num_side_channel_elements 4
132  // num_back_channel_elements 4
133  // num_lfe_channel_elements 2
134  // num_assoc_data_elements 3
135  // num_valid_cc_elements 4
136  // mono_mixdown_present 1
137  // mono_mixdown_element_number 4 if mono_mixdown_present == 1
138  // stereo_mixdown_present 1
139  // stereo_mixdown_element_number 4 if stereo_mixdown_present == 1
140  // matrix_mixdown_idx_present 1
141  // matrix_mixdown_idx 2 if matrix_mixdown_idx_present == 1
142  // pseudo_surround_enable 1 if matrix_mixdown_idx_present == 1
143  // for (i = 0; i < num_front_channel_elements; i++) {
144  // front_element_is_cpe[i] 1
145  // front_element_tag_select[i] 4
146  // }
147  // for (i = 0; i < num_side_channel_elements; i++) {
148  // side_element_is_cpe[i] 1
149  // side_element_tag_select[i] 4
150  // }
151  // for (i = 0; i < num_back_channel_elements; i++) {
152  // back_element_is_cpe[i] 1
153  // back_element_tag_select[i] 4
154  // }
155  // for (i = 0; i < num_lfe_channel_elements; i++) {
156  // lfe_element_tag_select[i] 4
157  // }
158  // for (i = 0; i < num_assoc_data_elements; i++) {
159  // assoc_data_element_tag_select[i] 4
160  // }
161  // for (i = 0; i < num_valid_cc_elements; i++) {
162  // cc_element_is_ind_sw[i] 1
163  // valid_cc_element_tag_select[i] 4
164  // }
165  // byte_alignment() VAR
166  // comment_field_bytes 8
167  // for (i = 0; i < comment_field_bytes; i++) {
168  // comment_field_data[i] 8
169  // }
170 
171  if (!$info['aac']['header']['is_vbr']) {
172  $info['aac']['program_configs'][$i]['buffer_fullness'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 20));
173  $bitoffset += 20;
174  }
175  $info['aac']['program_configs'][$i]['element_instance_tag'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
176  $bitoffset += 4;
177  $info['aac']['program_configs'][$i]['object_type'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2));
178  $bitoffset += 2;
179  $info['aac']['program_configs'][$i]['sampling_frequency_index'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
180  $bitoffset += 4;
181  $info['aac']['program_configs'][$i]['num_front_channel_elements'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
182  $bitoffset += 4;
183  $info['aac']['program_configs'][$i]['num_side_channel_elements'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
184  $bitoffset += 4;
185  $info['aac']['program_configs'][$i]['num_back_channel_elements'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
186  $bitoffset += 4;
187  $info['aac']['program_configs'][$i]['num_lfe_channel_elements'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2));
188  $bitoffset += 2;
189  $info['aac']['program_configs'][$i]['num_assoc_data_elements'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 3));
190  $bitoffset += 3;
191  $info['aac']['program_configs'][$i]['num_valid_cc_elements'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
192  $bitoffset += 4;
193  $info['aac']['program_configs'][$i]['mono_mixdown_present'] = (bool) Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
194  $bitoffset += 1;
195  if ($info['aac']['program_configs'][$i]['mono_mixdown_present']) {
196  $info['aac']['program_configs'][$i]['mono_mixdown_element_number'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
197  $bitoffset += 4;
198  }
199  $info['aac']['program_configs'][$i]['stereo_mixdown_present'] = (bool) Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
200  $bitoffset += 1;
201  if ($info['aac']['program_configs'][$i]['stereo_mixdown_present']) {
202  $info['aac']['program_configs'][$i]['stereo_mixdown_element_number'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
203  $bitoffset += 4;
204  }
205  $info['aac']['program_configs'][$i]['matrix_mixdown_idx_present'] = (bool) Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
206  $bitoffset += 1;
207  if ($info['aac']['program_configs'][$i]['matrix_mixdown_idx_present']) {
208  $info['aac']['program_configs'][$i]['matrix_mixdown_idx'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2));
209  $bitoffset += 2;
210  $info['aac']['program_configs'][$i]['pseudo_surround_enable'] = (bool) Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
211  $bitoffset += 1;
212  }
213  for ($j = 0; $j < $info['aac']['program_configs'][$i]['num_front_channel_elements']; $j++) {
214  $info['aac']['program_configs'][$i]['front_element_is_cpe'][$j] = (bool) Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
215  $bitoffset += 1;
216  $info['aac']['program_configs'][$i]['front_element_tag_select'][$j] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
217  $bitoffset += 4;
218  }
219  for ($j = 0; $j < $info['aac']['program_configs'][$i]['num_side_channel_elements']; $j++) {
220  $info['aac']['program_configs'][$i]['side_element_is_cpe'][$j] = (bool) Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
221  $bitoffset += 1;
222  $info['aac']['program_configs'][$i]['side_element_tag_select'][$j] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
223  $bitoffset += 4;
224  }
225  for ($j = 0; $j < $info['aac']['program_configs'][$i]['num_back_channel_elements']; $j++) {
226  $info['aac']['program_configs'][$i]['back_element_is_cpe'][$j] = (bool) Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
227  $bitoffset += 1;
228  $info['aac']['program_configs'][$i]['back_element_tag_select'][$j] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
229  $bitoffset += 4;
230  }
231  for ($j = 0; $j < $info['aac']['program_configs'][$i]['num_lfe_channel_elements']; $j++) {
232  $info['aac']['program_configs'][$i]['lfe_element_tag_select'][$j] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
233  $bitoffset += 4;
234  }
235  for ($j = 0; $j < $info['aac']['program_configs'][$i]['num_assoc_data_elements']; $j++) {
236  $info['aac']['program_configs'][$i]['assoc_data_element_tag_select'][$j] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
237  $bitoffset += 4;
238  }
239  for ($j = 0; $j < $info['aac']['program_configs'][$i]['num_valid_cc_elements']; $j++) {
240  $info['aac']['program_configs'][$i]['cc_element_is_ind_sw'][$j] = (bool) Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
241  $bitoffset += 1;
242  $info['aac']['program_configs'][$i]['valid_cc_element_tag_select'][$j] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
243  $bitoffset += 4;
244  }
245 
246  $bitoffset = ceil($bitoffset / 8) * 8;
247 
248  $info['aac']['program_configs'][$i]['comment_field_bytes'] = Helper::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 8));
249  $bitoffset += 8;
250  $info['aac']['program_configs'][$i]['comment_field'] = Helper::Bin2String(substr($AACheaderBitstream, $bitoffset, 8 * $info['aac']['program_configs'][$i]['comment_field_bytes']));
251  $bitoffset += 8 * $info['aac']['program_configs'][$i]['comment_field_bytes'];
252 
253  $info['aac']['header']['profile'] = self::AACprofileLookup($info['aac']['program_configs'][$i]['object_type'], $info['aac']['header']['mpeg_version']);
254  $info['aac']['program_configs'][$i]['sampling_frequency'] = self::AACsampleRateLookup($info['aac']['program_configs'][$i]['sampling_frequency_index']);
255  $info['audio']['sample_rate'] = $info['aac']['program_configs'][$i]['sampling_frequency'];
256  $info['audio']['channels'] = self::AACchannelCountCalculate($info['aac']['program_configs'][$i]);
257  if ($info['aac']['program_configs'][$i]['comment_field']) {
258  $info['aac']['comments'][] = $info['aac']['program_configs'][$i]['comment_field'];
259  }
260  }
261  $info['playtime_seconds'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['audio']['bitrate'];
262 
263  $info['audio']['encoder_options'] = $info['aac']['header_type'].' '.$info['aac']['header']['profile'];
264 
265  return true;
266 
267  } else {
268 
269  unset($info['fileformat']);
270  unset($info['aac']);
271  $info['error'][] = 'AAC-ADIF synch not found at offset '.$info['avdataoffset'].' (expected "ADIF", found "'.substr($AACheader, 0, 4).'" instead)';
272 
273  return false;
274 
275  }
276 
277  }
GetId3\Lib\Helper\BigEndian2Bin
static BigEndian2Bin($byteword)
Definition: Helper.php:423
GetId3\Handler\BaseHandler\fseek
fseek($bytes, $whence=SEEK_SET)
Definition: BaseHandler.php:148
$info
$info
Definition: example_052.php:80
GetId3\Lib\Helper\Bin2String
static Bin2String($binstring)
Definition: Helper.php:519
GetId3\Lib\Helper\Bin2Dec
static Bin2Dec($binstring, $signed=false)
Definition: Helper.php:496
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◆ getAACADTSheaderFilepointer()

GetId3\Module\Audio\Aac::getAACADTSheaderFilepointer (   $MaxFramesToScan = 1000000,
  $ReturnExtendedInfo = false 
)

array $decbin

Parameters
type$MaxFramesToScan
type$ReturnExtendedInfo
Returns
boolean

Definition at line 286 of file Aac.php.

References $info, array, GetId3\Lib\Helper\BigEndian2Int(), GetId3\Handler\BaseHandler\fread(), GetId3\Handler\BaseHandler\fseek(), GetId3\Lib\Helper\intValueSupported(), and GetId3\Lib\Helper\safe_inc().

Referenced by GetId3\Module\Audio\Aac\analyze().

287  {
288  $info = &$this->getid3->info;
289 
290  // based loosely on code from AACfile by Jurgen Faul <jfaulØgmx.de>
291  // http://jfaul.de/atl or http://j-faul.virtualave.net/atl/atl.html
292 
293  // http://faac.sourceforge.net/wiki/index.php?page=ADTS // dead link
294  // http://wiki.multimedia.cx/index.php?title=ADTS
295 
296  // * ADTS Fixed Header: these don't change from frame to frame
297  // syncword 12 always: '111111111111'
298  // ID 1 0: MPEG-4, 1: MPEG-2
299  // MPEG layer 2 If you send AAC in MPEG-TS, set to 0
300  // protection_absent 1 0: CRC present; 1: no CRC
301  // profile 2 0: AAC Main; 1: AAC LC (Low Complexity); 2: AAC SSR (Scalable Sample Rate); 3: AAC LTP (Long Term Prediction)
302  // sampling_frequency_index 4 15 not allowed
303  // private_bit 1 usually 0
304  // channel_configuration 3
305  // original/copy 1 0: original; 1: copy
306  // home 1 usually 0
307  // emphasis 2 only if ID == 0 (ie MPEG-4) // not present in some documentation?
308 
309  // * ADTS Variable Header: these can change from frame to frame
310  // copyright_identification_bit 1
311  // copyright_identification_start 1
312  // aac_frame_length 13 length of the frame including header (in bytes)
313  // adts_buffer_fullness 11 0x7FF indicates VBR
314  // no_raw_data_blocks_in_frame 2
315 
316  // * ADTS Error check
317  // crc_check 16 only if protection_absent == 0
318 
319  $byteoffset = $info['avdataoffset'];
320  $framenumber = 0;
321 
322  // Init bit pattern array
323  static $decbin = array();
324 
325  // Populate $bindec
326  for ($i = 0; $i < 256; $i++) {
327  $decbin[chr($i)] = str_pad(decbin($i), 8, '0', STR_PAD_LEFT);
328  }
329 
330  // used to calculate bitrate below
331  $BitrateCache = array();
332 
333 
334  while (true) {
335  // breaks out when end-of-file encountered, or invalid data found,
336  // or MaxFramesToScan frames have been scanned
337 
338  if (!Helper::intValueSupported($byteoffset)) {
339  $info['warning'][] = 'Unable to parse AAC file beyond '.ftell($this->getid3->fp).' (PHP does not support file operations beyond '.round(PHP_INT_MAX / 1073741824).'GB)';
340 
341  return false;
342  }
343  fseek($this->getid3->fp, $byteoffset, SEEK_SET);
344 
345  // First get substring
346  $substring = fread($this->getid3->fp, 9); // header is 7 bytes (or 9 if CRC is present)
347  $substringlength = strlen($substring);
348  if ($substringlength != 9) {
349  $info['error'][] = 'Failed to read 7 bytes at offset '.(ftell($this->getid3->fp) - $substringlength).' (only read '.$substringlength.' bytes)';
350 
351  return false;
352  }
353  // this would be easier with 64-bit math, but split it up to allow for 32-bit:
354  $header1 = Helper::BigEndian2Int(substr($substring, 0, 2));
355  $header2 = Helper::BigEndian2Int(substr($substring, 2, 4));
356  $header3 = Helper::BigEndian2Int(substr($substring, 6, 1));
357 
358  $info['aac']['header']['raw']['syncword'] = ($header1 & 0xFFF0) >> 4;
359  if ($info['aac']['header']['raw']['syncword'] != 0x0FFF) {
360  $info['error'][] = 'Synch pattern (0x0FFF) not found at offset '.(ftell($this->getid3->fp) - $substringlength).' (found 0x0'.strtoupper(dechex($info['aac']['header']['raw']['syncword'])).' instead)';
361  //if ($info['fileformat'] == 'aac') {
362  // return true;
363  //}
364  unset($info['aac']);
365 
366  return false;
367  }
368 
369  // Gather info for first frame only - this takes time to do 1000 times!
370  if ($framenumber == 0) {
371  $info['aac']['header_type'] = 'ADTS';
372  $info['fileformat'] = 'aac';
373  $info['audio']['dataformat'] = 'aac';
374 
375  $info['aac']['header']['raw']['mpeg_version'] = ($header1 & 0x0008) >> 3;
376  $info['aac']['header']['raw']['mpeg_layer'] = ($header1 & 0x0006) >> 1;
377  $info['aac']['header']['raw']['protection_absent'] = ($header1 & 0x0001) >> 0;
378 
379  $info['aac']['header']['raw']['profile_code'] = ($header2 & 0xC0000000) >> 30;
380  $info['aac']['header']['raw']['sample_rate_code'] = ($header2 & 0x3C000000) >> 26;
381  $info['aac']['header']['raw']['private_stream'] = ($header2 & 0x02000000) >> 25;
382  $info['aac']['header']['raw']['channels_code'] = ($header2 & 0x01C00000) >> 22;
383  $info['aac']['header']['raw']['original'] = ($header2 & 0x00200000) >> 21;
384  $info['aac']['header']['raw']['home'] = ($header2 & 0x00100000) >> 20;
385  $info['aac']['header']['raw']['copyright_stream'] = ($header2 & 0x00080000) >> 19;
386  $info['aac']['header']['raw']['copyright_start'] = ($header2 & 0x00040000) >> 18;
387  $info['aac']['header']['raw']['frame_length'] = ($header2 & 0x0003FFE0) >> 5;
388 
389  $info['aac']['header']['mpeg_version'] = ($info['aac']['header']['raw']['mpeg_version'] ? 2 : 4);
390  $info['aac']['header']['crc_present'] = ($info['aac']['header']['raw']['protection_absent'] ? false: true);
391  $info['aac']['header']['profile'] = self::AACprofileLookup($info['aac']['header']['raw']['profile_code'], $info['aac']['header']['mpeg_version']);
392  $info['aac']['header']['sample_frequency'] = self::AACsampleRateLookup($info['aac']['header']['raw']['sample_rate_code']);
393  $info['aac']['header']['private'] = (bool) $info['aac']['header']['raw']['private_stream'];
394  $info['aac']['header']['original'] = (bool) $info['aac']['header']['raw']['original'];
395  $info['aac']['header']['home'] = (bool) $info['aac']['header']['raw']['home'];
396  $info['aac']['header']['channels'] = (($info['aac']['header']['raw']['channels_code'] == 7) ? 8 : $info['aac']['header']['raw']['channels_code']);
397  if ($ReturnExtendedInfo) {
398  $info['aac'][$framenumber]['copyright_id_bit'] = (bool) $info['aac']['header']['raw']['copyright_stream'];
399  $info['aac'][$framenumber]['copyright_id_start'] = (bool) $info['aac']['header']['raw']['copyright_start'];
400  }
401 
402  if ($info['aac']['header']['raw']['mpeg_layer'] != 0) {
403  $info['warning'][] = 'Layer error - expected "0", found "'.$info['aac']['header']['raw']['mpeg_layer'].'" instead';
404  }
405  if ($info['aac']['header']['sample_frequency'] == 0) {
406  $info['error'][] = 'Corrupt AAC file: sample_frequency == zero';
407 
408  return false;
409  }
410 
411  $info['audio']['sample_rate'] = $info['aac']['header']['sample_frequency'];
412  $info['audio']['channels'] = $info['aac']['header']['channels'];
413  }
414 
415  $FrameLength = ($header2 & 0x0003FFE0) >> 5;
416 
417  if (!isset($BitrateCache[$FrameLength])) {
418  $BitrateCache[$FrameLength] = ($info['aac']['header']['sample_frequency'] / 1024) * $FrameLength * 8;
419  }
420  Helper::safe_inc($info['aac']['bitrate_distribution'][$BitrateCache[$FrameLength]], 1);
421 
422  $info['aac'][$framenumber]['aac_frame_length'] = $FrameLength;
423 
424  $info['aac'][$framenumber]['adts_buffer_fullness'] = (($header2 & 0x0000001F) << 6) & (($header3 & 0xFC) >> 2);
425  if ($info['aac'][$framenumber]['adts_buffer_fullness'] == 0x07FF) {
426  $info['audio']['bitrate_mode'] = 'vbr';
427  } else {
428  $info['audio']['bitrate_mode'] = 'cbr';
429  }
430  $info['aac'][$framenumber]['num_raw_data_blocks'] = (($header3 & 0x03) >> 0);
431 
432  if ($info['aac']['header']['crc_present']) {
433  //$info['aac'][$framenumber]['crc'] = GetId3_lib::BigEndian2Int(substr($substring, 7, 2);
434  }
435 
436  if (!$ReturnExtendedInfo) {
437  unset($info['aac'][$framenumber]);
438  }
439 
440  /*
441  $rounded_precision = 5000;
442  $info['aac']['bitrate_distribution_rounded'] = array();
443  foreach ($info['aac']['bitrate_distribution'] as $bitrate => $count) {
444  $rounded_bitrate = round($bitrate / $rounded_precision) * $rounded_precision;
445  getid3_lib::safe_inc($info['aac']['bitrate_distribution_rounded'][$rounded_bitrate], $count);
446  }
447  ksort($info['aac']['bitrate_distribution_rounded']);
448  */
449 
450  $byteoffset += $FrameLength;
451  if ((++$framenumber < $MaxFramesToScan) && (($byteoffset + 10) < $info['avdataend'])) {
452 
453  // keep scanning
454 
455  } else {
456 
457  $info['aac']['frames'] = $framenumber;
458  $info['playtime_seconds'] = ($info['avdataend'] / $byteoffset) * (($framenumber * 1024) / $info['aac']['header']['sample_frequency']); // (1 / % of file scanned) * (samples / (samples/sec)) = seconds
459  if ($info['playtime_seconds'] == 0) {
460  $info['error'][] = 'Corrupt AAC file: playtime_seconds == zero';
461 
462  return false;
463  }
464  $info['audio']['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
465  ksort($info['aac']['bitrate_distribution']);
466 
467  $info['audio']['encoder_options'] = $info['aac']['header_type'].' '.$info['aac']['header']['profile'];
468 
469  return true;
470 
471  }
472  }
473  // should never get here.
474  }
GetId3\Handler\BaseHandler\fseek
fseek($bytes, $whence=SEEK_SET)
Definition: BaseHandler.php:148
$info
$info
Definition: example_052.php:80
array
Create styles array
The data for the language used.
Definition: 40duplicateStyle.php:19
GetId3\Lib\Helper\BigEndian2Int
static BigEndian2Int($byteword, $synchsafe=false, $signed=false)
Definition: Helper.php:374
GetId3\Lib\Helper\intValueSupported
static intValueSupported($num)
null $hasINT64
Definition: Helper.php:130
GetId3\Lib\Helper\safe_inc
static safe_inc(&$variable, $increment=1)
Definition: Helper.php:91
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