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-rw-r--r--getid3/module.audio.aac.php542
1 files changed, 542 insertions, 0 deletions
diff --git a/getid3/module.audio.aac.php b/getid3/module.audio.aac.php
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+++ b/getid3/module.audio.aac.php
@@ -0,0 +1,542 @@
+<?php
+/////////////////////////////////////////////////////////////////
+/// getID3() by James Heinrich <info@getid3.org> //
+// available at http://getid3.sourceforge.net //
+// or http://www.getid3.org //
+/////////////////////////////////////////////////////////////////
+// See readme.txt for more details //
+/////////////////////////////////////////////////////////////////
+// //
+// module.audio.aac.php //
+// module for analyzing AAC Audio files //
+// dependencies: NONE //
+// ///
+/////////////////////////////////////////////////////////////////
+
+
+class getid3_aac
+{
+
+ // new combined constructor
+ function getid3_aac(&$fd, &$ThisFileInfo, $option) {
+
+ if ($option === 'adif') {
+ $this->getAACADIFheaderFilepointer($fd, $ThisFileInfo);
+ }
+ elseif ($option === 'adts') {
+ $this->getAACADTSheaderFilepointer($fd, $ThisFileInfo);
+ }
+ }
+
+
+
+ function getAACADIFheaderFilepointer(&$fd, &$ThisFileInfo) {
+ $ThisFileInfo['fileformat'] = 'aac';
+ $ThisFileInfo['audio']['dataformat'] = 'aac';
+ $ThisFileInfo['audio']['lossless'] = false;
+
+ fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);
+ $AACheader = fread($fd, 1024);
+ $offset = 0;
+
+ if (substr($AACheader, 0, 4) == 'ADIF') {
+
+ // http://faac.sourceforge.net/wiki/index.php?page=ADIF
+
+ // http://libmpeg.org/mpeg4/doc/w2203tfs.pdf
+ // adif_header() {
+ // adif_id 32
+ // copyright_id_present 1
+ // if( copyright_id_present )
+ // copyright_id 72
+ // original_copy 1
+ // home 1
+ // bitstream_type 1
+ // bitrate 23
+ // num_program_config_elements 4
+ // for (i = 0; i < num_program_config_elements + 1; i++ ) {
+ // if( bitstream_type == '0' )
+ // adif_buffer_fullness 20
+ // program_config_element()
+ // }
+ // }
+
+ $AACheaderBitstream = getid3_lib::BigEndian2Bin($AACheader);
+ $bitoffset = 0;
+
+ $ThisFileInfo['aac']['header_type'] = 'ADIF';
+ $bitoffset += 32;
+ $ThisFileInfo['aac']['header']['mpeg_version'] = 4;
+
+ $ThisFileInfo['aac']['header']['copyright'] = (bool) (substr($AACheaderBitstream, $bitoffset, 1) == '1');
+ $bitoffset += 1;
+ if ($ThisFileInfo['aac']['header']['copyright']) {
+ $ThisFileInfo['aac']['header']['copyright_id'] = getid3_lib::Bin2String(substr($AACheaderBitstream, $bitoffset, 72));
+ $bitoffset += 72;
+ }
+ $ThisFileInfo['aac']['header']['original_copy'] = (bool) (substr($AACheaderBitstream, $bitoffset, 1) == '1');
+ $bitoffset += 1;
+ $ThisFileInfo['aac']['header']['home'] = (bool) (substr($AACheaderBitstream, $bitoffset, 1) == '1');
+ $bitoffset += 1;
+ $ThisFileInfo['aac']['header']['is_vbr'] = (bool) (substr($AACheaderBitstream, $bitoffset, 1) == '1');
+ $bitoffset += 1;
+ if ($ThisFileInfo['aac']['header']['is_vbr']) {
+ $ThisFileInfo['audio']['bitrate_mode'] = 'vbr';
+ $ThisFileInfo['aac']['header']['bitrate_max'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 23));
+ $bitoffset += 23;
+ } else {
+ $ThisFileInfo['audio']['bitrate_mode'] = 'cbr';
+ $ThisFileInfo['aac']['header']['bitrate'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 23));
+ $bitoffset += 23;
+ $ThisFileInfo['audio']['bitrate'] = $ThisFileInfo['aac']['header']['bitrate'];
+ }
+ if ($ThisFileInfo['audio']['bitrate'] == 0) {
+ $ThisFileInfo['error'][] = 'Corrupt AAC file: bitrate_audio == zero';
+ return false;
+ }
+ $ThisFileInfo['aac']['header']['num_program_configs'] = 1 + getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+
+ for ($i = 0; $i < $ThisFileInfo['aac']['header']['num_program_configs']; $i++) {
+ // http://www.audiocoding.com/wiki/index.php?page=program_config_element
+
+ // buffer_fullness 20
+
+ // element_instance_tag 4
+ // object_type 2
+ // sampling_frequency_index 4
+ // num_front_channel_elements 4
+ // num_side_channel_elements 4
+ // num_back_channel_elements 4
+ // num_lfe_channel_elements 2
+ // num_assoc_data_elements 3
+ // num_valid_cc_elements 4
+ // mono_mixdown_present 1
+ // mono_mixdown_element_number 4 if mono_mixdown_present == 1
+ // stereo_mixdown_present 1
+ // stereo_mixdown_element_number 4 if stereo_mixdown_present == 1
+ // matrix_mixdown_idx_present 1
+ // matrix_mixdown_idx 2 if matrix_mixdown_idx_present == 1
+ // pseudo_surround_enable 1 if matrix_mixdown_idx_present == 1
+ // for (i = 0; i < num_front_channel_elements; i++) {
+ // front_element_is_cpe[i] 1
+ // front_element_tag_select[i] 4
+ // }
+ // for (i = 0; i < num_side_channel_elements; i++) {
+ // side_element_is_cpe[i] 1
+ // side_element_tag_select[i] 4
+ // }
+ // for (i = 0; i < num_back_channel_elements; i++) {
+ // back_element_is_cpe[i] 1
+ // back_element_tag_select[i] 4
+ // }
+ // for (i = 0; i < num_lfe_channel_elements; i++) {
+ // lfe_element_tag_select[i] 4
+ // }
+ // for (i = 0; i < num_assoc_data_elements; i++) {
+ // assoc_data_element_tag_select[i] 4
+ // }
+ // for (i = 0; i < num_valid_cc_elements; i++) {
+ // cc_element_is_ind_sw[i] 1
+ // valid_cc_element_tag_select[i] 4
+ // }
+ // byte_alignment() VAR
+ // comment_field_bytes 8
+ // for (i = 0; i < comment_field_bytes; i++) {
+ // comment_field_data[i] 8
+ // }
+
+ if (!$ThisFileInfo['aac']['header']['is_vbr']) {
+ $ThisFileInfo['aac']['program_configs'][$i]['buffer_fullness'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 20));
+ $bitoffset += 20;
+ }
+ $ThisFileInfo['aac']['program_configs'][$i]['element_instance_tag'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ $ThisFileInfo['aac']['program_configs'][$i]['object_type'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2));
+ $bitoffset += 2;
+ $ThisFileInfo['aac']['program_configs'][$i]['sampling_frequency_index'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ $ThisFileInfo['aac']['program_configs'][$i]['num_front_channel_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ $ThisFileInfo['aac']['program_configs'][$i]['num_side_channel_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ $ThisFileInfo['aac']['program_configs'][$i]['num_back_channel_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ $ThisFileInfo['aac']['program_configs'][$i]['num_lfe_channel_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2));
+ $bitoffset += 2;
+ $ThisFileInfo['aac']['program_configs'][$i]['num_assoc_data_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 3));
+ $bitoffset += 3;
+ $ThisFileInfo['aac']['program_configs'][$i]['num_valid_cc_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ $ThisFileInfo['aac']['program_configs'][$i]['mono_mixdown_present'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
+ $bitoffset += 1;
+ if ($ThisFileInfo['aac']['program_configs'][$i]['mono_mixdown_present']) {
+ $ThisFileInfo['aac']['program_configs'][$i]['mono_mixdown_element_number'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ }
+ $ThisFileInfo['aac']['program_configs'][$i]['stereo_mixdown_present'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
+ $bitoffset += 1;
+ if ($ThisFileInfo['aac']['program_configs'][$i]['stereo_mixdown_present']) {
+ $ThisFileInfo['aac']['program_configs'][$i]['stereo_mixdown_element_number'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ }
+ $ThisFileInfo['aac']['program_configs'][$i]['matrix_mixdown_idx_present'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
+ $bitoffset += 1;
+ if ($ThisFileInfo['aac']['program_configs'][$i]['matrix_mixdown_idx_present']) {
+ $ThisFileInfo['aac']['program_configs'][$i]['matrix_mixdown_idx'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2));
+ $bitoffset += 2;
+ $ThisFileInfo['aac']['program_configs'][$i]['pseudo_surround_enable'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
+ $bitoffset += 1;
+ }
+ for ($j = 0; $j < $ThisFileInfo['aac']['program_configs'][$i]['num_front_channel_elements']; $j++) {
+ $ThisFileInfo['aac']['program_configs'][$i]['front_element_is_cpe'][$j] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
+ $bitoffset += 1;
+ $ThisFileInfo['aac']['program_configs'][$i]['front_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ }
+ for ($j = 0; $j < $ThisFileInfo['aac']['program_configs'][$i]['num_side_channel_elements']; $j++) {
+ $ThisFileInfo['aac']['program_configs'][$i]['side_element_is_cpe'][$j] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
+ $bitoffset += 1;
+ $ThisFileInfo['aac']['program_configs'][$i]['side_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ }
+ for ($j = 0; $j < $ThisFileInfo['aac']['program_configs'][$i]['num_back_channel_elements']; $j++) {
+ $ThisFileInfo['aac']['program_configs'][$i]['back_element_is_cpe'][$j] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
+ $bitoffset += 1;
+ $ThisFileInfo['aac']['program_configs'][$i]['back_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ }
+ for ($j = 0; $j < $ThisFileInfo['aac']['program_configs'][$i]['num_lfe_channel_elements']; $j++) {
+ $ThisFileInfo['aac']['program_configs'][$i]['lfe_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ }
+ for ($j = 0; $j < $ThisFileInfo['aac']['program_configs'][$i]['num_assoc_data_elements']; $j++) {
+ $ThisFileInfo['aac']['program_configs'][$i]['assoc_data_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ }
+ for ($j = 0; $j < $ThisFileInfo['aac']['program_configs'][$i]['num_valid_cc_elements']; $j++) {
+ $ThisFileInfo['aac']['program_configs'][$i]['cc_element_is_ind_sw'][$j] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
+ $bitoffset += 1;
+ $ThisFileInfo['aac']['program_configs'][$i]['valid_cc_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ }
+
+ $bitoffset = ceil($bitoffset / 8) * 8;
+
+ $ThisFileInfo['aac']['program_configs'][$i]['comment_field_bytes'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 8));
+ $bitoffset += 8;
+ $ThisFileInfo['aac']['program_configs'][$i]['comment_field'] = getid3_lib::Bin2String(substr($AACheaderBitstream, $bitoffset, 8 * $ThisFileInfo['aac']['program_configs'][$i]['comment_field_bytes']));
+ $bitoffset += 8 * $ThisFileInfo['aac']['program_configs'][$i]['comment_field_bytes'];
+
+
+ $ThisFileInfo['aac']['header']['profile_text'] = $this->AACprofileLookup($ThisFileInfo['aac']['program_configs'][$i]['object_type'], $ThisFileInfo['aac']['header']['mpeg_version']);
+ $ThisFileInfo['aac']['program_configs'][$i]['sampling_frequency'] = $this->AACsampleRateLookup($ThisFileInfo['aac']['program_configs'][$i]['sampling_frequency_index']);
+ $ThisFileInfo['audio']['sample_rate'] = $ThisFileInfo['aac']['program_configs'][$i]['sampling_frequency'];
+ $ThisFileInfo['audio']['channels'] = $this->AACchannelCountCalculate($ThisFileInfo['aac']['program_configs'][$i]);
+ if ($ThisFileInfo['aac']['program_configs'][$i]['comment_field']) {
+ $ThisFileInfo['aac']['comments'][] = $ThisFileInfo['aac']['program_configs'][$i]['comment_field'];
+ }
+ }
+ $ThisFileInfo['playtime_seconds'] = (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8) / $ThisFileInfo['audio']['bitrate'];
+
+ $ThisFileInfo['audio']['encoder_options'] = $ThisFileInfo['aac']['header_type'].' '.$ThisFileInfo['aac']['header']['profile_text'];
+
+
+
+ return true;
+
+ } else {
+
+ unset($ThisFileInfo['fileformat']);
+ unset($ThisFileInfo['aac']);
+ $ThisFileInfo['error'][] = 'AAC-ADIF synch not found at offset '.$ThisFileInfo['avdataoffset'].' (expected "ADIF", found "'.substr($AACheader, 0, 4).'" instead)';
+ return false;
+
+ }
+
+ }
+
+
+ function getAACADTSheaderFilepointer(&$fd, &$ThisFileInfo, $MaxFramesToScan=1000000, $ReturnExtendedInfo=false) {
+ // based loosely on code from AACfile by Jurgen Faul <jfaulØgmx.de>
+ // http://jfaul.de/atl or http://j-faul.virtualave.net/atl/atl.html
+
+
+ // http://faac.sourceforge.net/wiki/index.php?page=ADTS
+
+ // * ADTS Fixed Header: these don't change from frame to frame
+ // syncword 12 always: '111111111111'
+ // ID 1 0: MPEG-4, 1: MPEG-2
+ // layer 2 always: '00'
+ // protection_absent 1
+ // profile 2
+ // sampling_frequency_index 4
+ // private_bit 1
+ // channel_configuration 3
+ // original/copy 1
+ // home 1
+ // emphasis 2 only if ID == 0 (ie MPEG-4)
+
+ // * ADTS Variable Header: these can change from frame to frame
+ // copyright_identification_bit 1
+ // copyright_identification_start 1
+ // aac_frame_length 13 length of the frame including header (in bytes)
+ // adts_buffer_fullness 11 0x7FF indicates VBR
+ // no_raw_data_blocks_in_frame 2
+
+ // * ADTS Error check
+ // crc_check 16 only if protection_absent == 0
+
+ $byteoffset = 0;
+ $framenumber = 0;
+
+ // Init bit pattern array
+ static $decbin = array();
+
+ // Populate $bindec
+ for ($i = 0; $i < 256; $i++) {
+ $decbin[chr($i)] = str_pad(decbin($i), 8, '0', STR_PAD_LEFT);
+ }
+
+ // used to calculate bitrate below
+ $BitrateCache = array();
+
+
+ while (true) {
+ // breaks out when end-of-file encountered, or invalid data found,
+ // or MaxFramesToScan frames have been scanned
+
+ if ($byteoffset >= pow(2, 31)) {
+ $ThisFileInfo['warning'][] = 'Unable to parse AAC file beyond '.ftell($fd).' (PHP does not support file operations beyond 2GB)';
+ return false;
+ }
+ fseek($fd, $byteoffset, SEEK_SET);
+
+ // First get substring
+ $substring = fread($fd, 10);
+ $substringlength = strlen($substring);
+ if ($substringlength != 10) {
+ $ThisFileInfo['error'][] = 'Failed to read 10 bytes at offset '.(ftell($fd) - $substringlength).' (only read '.$substringlength.' bytes)';
+ return false;
+ }
+
+ // Initialise $AACheaderBitstream
+ $AACheaderBitstream = '';
+
+ // Loop thru substring chars
+ for ($i = 0; $i < 10; $i++) {
+ $AACheaderBitstream .= $decbin[$substring{$i}];
+ }
+
+ $bitoffset = 0;
+
+ $synctest = bindec(substr($AACheaderBitstream, $bitoffset, 12));
+
+ $bitoffset += 12;
+ if ($synctest != 0x0FFF) {
+ $ThisFileInfo['error'][] = 'Synch pattern (0x0FFF) not found at offset '.(ftell($fd) - 10).' (found 0x0'.strtoupper(dechex($synctest)).' instead)';
+ if ($ThisFileInfo['fileformat'] == 'aac') {
+ return true;
+ }
+ return false;
+ }
+
+ // Gather info for first frame only - this takes time to do 1000 times!
+ if ($framenumber > 0) {
+
+ if (!$AACheaderBitstream[$bitoffset]) {
+
+ // MPEG-4
+ $bitoffset += 20;
+
+ } else {
+
+ // MPEG-2
+ $bitoffset += 18;
+
+ }
+
+ } else {
+
+ $ThisFileInfo['aac']['header_type'] = 'ADTS';
+ $ThisFileInfo['aac']['header']['synch'] = $synctest;
+ $ThisFileInfo['fileformat'] = 'aac';
+ $ThisFileInfo['audio']['dataformat'] = 'aac';
+
+ $ThisFileInfo['aac']['header']['mpeg_version'] = ((substr($AACheaderBitstream, $bitoffset, 1) == '0') ? 4 : 2);
+ $bitoffset += 1;
+ $ThisFileInfo['aac']['header']['layer'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2));
+ $bitoffset += 2;
+ if ($ThisFileInfo['aac']['header']['layer'] != 0) {
+ $ThisFileInfo['error'][] = 'Layer error - expected 0x00, found 0x'.dechex($ThisFileInfo['aac']['header']['layer']).' instead';
+ return false;
+ }
+ $ThisFileInfo['aac']['header']['crc_present'] = ((substr($AACheaderBitstream, $bitoffset, 1) == '0') ? true : false);
+ $bitoffset += 1;
+ $ThisFileInfo['aac']['header']['profile_id'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2));
+ $bitoffset += 2;
+ $ThisFileInfo['aac']['header']['profile_text'] = $this->AACprofileLookup($ThisFileInfo['aac']['header']['profile_id'], $ThisFileInfo['aac']['header']['mpeg_version']);
+
+ $ThisFileInfo['aac']['header']['sample_frequency_index'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4));
+ $bitoffset += 4;
+ $ThisFileInfo['aac']['header']['sample_frequency'] = $this->AACsampleRateLookup($ThisFileInfo['aac']['header']['sample_frequency_index']);
+ if ($ThisFileInfo['aac']['header']['sample_frequency'] == 0) {
+ $ThisFileInfo['error'][] = 'Corrupt AAC file: sample_frequency == zero';
+ return false;
+ }
+ $ThisFileInfo['audio']['sample_rate'] = $ThisFileInfo['aac']['header']['sample_frequency'];
+
+ $ThisFileInfo['aac']['header']['private'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
+ $bitoffset += 1;
+ $ThisFileInfo['aac']['header']['channel_configuration'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 3));
+ $bitoffset += 3;
+ $ThisFileInfo['audio']['channels'] = $ThisFileInfo['aac']['header']['channel_configuration'];
+ $ThisFileInfo['aac']['header']['original'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
+ $bitoffset += 1;
+ $ThisFileInfo['aac']['header']['home'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
+ $bitoffset += 1;
+
+ if ($ThisFileInfo['aac']['header']['mpeg_version'] == 4) {
+ $ThisFileInfo['aac']['header']['emphasis'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2));
+ $bitoffset += 2;
+ }
+
+ if ($ReturnExtendedInfo) {
+
+ $ThisFileInfo['aac'][$framenumber]['copyright_id_bit'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
+ $bitoffset += 1;
+ $ThisFileInfo['aac'][$framenumber]['copyright_id_start'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1));
+ $bitoffset += 1;
+
+ } else {
+
+ $bitoffset += 2;
+
+ }
+
+ }
+
+ $FrameLength = bindec(substr($AACheaderBitstream, $bitoffset, 13));
+
+ if (!isset($BitrateCache[$FrameLength])) {
+ $BitrateCache[$FrameLength] = ($ThisFileInfo['aac']['header']['sample_frequency'] / 1024) * $FrameLength * 8;
+ }
+ @$ThisFileInfo['aac']['bitrate_distribution'][$BitrateCache[$FrameLength]]++;
+
+ $ThisFileInfo['aac'][$framenumber]['aac_frame_length'] = $FrameLength;
+ $bitoffset += 13;
+ $ThisFileInfo['aac'][$framenumber]['adts_buffer_fullness'] = bindec(substr($AACheaderBitstream, $bitoffset, 11));
+ $bitoffset += 11;
+ if ($ThisFileInfo['aac'][$framenumber]['adts_buffer_fullness'] == 0x07FF) {
+ $ThisFileInfo['audio']['bitrate_mode'] = 'vbr';
+ } else {
+ $ThisFileInfo['audio']['bitrate_mode'] = 'cbr';
+ }
+ $ThisFileInfo['aac'][$framenumber]['num_raw_data_blocks'] = bindec(substr($AACheaderBitstream, $bitoffset, 2));
+ $bitoffset += 2;
+
+ if ($ThisFileInfo['aac']['header']['crc_present']) {
+ //$ThisFileInfo['aac'][$framenumber]['crc'] = bindec(substr($AACheaderBitstream, $bitoffset, 16));
+ $bitoffset += 16;
+ }
+
+ if (!$ReturnExtendedInfo) {
+ unset($ThisFileInfo['aac'][$framenumber]);
+ }
+
+ $byteoffset += $FrameLength;
+ if ((++$framenumber < $MaxFramesToScan) && (($byteoffset + 10) < $ThisFileInfo['avdataend'])) {
+
+ // keep scanning
+
+ } else {
+
+ $ThisFileInfo['aac']['frames'] = $framenumber;
+ $ThisFileInfo['playtime_seconds'] = ($ThisFileInfo['avdataend'] / $byteoffset) * (($framenumber * 1024) / $ThisFileInfo['aac']['header']['sample_frequency']); // (1 / % of file scanned) * (samples / (samples/sec)) = seconds
+ if ($ThisFileInfo['playtime_seconds'] == 0) {
+ $ThisFileInfo['error'][] = 'Corrupt AAC file: playtime_seconds == zero';
+ return false;
+ }
+ $ThisFileInfo['audio']['bitrate'] = (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8) / $ThisFileInfo['playtime_seconds'];
+ ksort($ThisFileInfo['aac']['bitrate_distribution']);
+
+ $ThisFileInfo['audio']['encoder_options'] = $ThisFileInfo['aac']['header_type'].' '.$ThisFileInfo['aac']['header']['profile_text'];
+
+ return true;
+
+ }
+ }
+ // should never get here.
+ }
+
+ function AACsampleRateLookup($samplerateid) {
+ static $AACsampleRateLookup = array();
+ if (empty($AACsampleRateLookup)) {
+ $AACsampleRateLookup[0] = 96000;
+ $AACsampleRateLookup[1] = 88200;
+ $AACsampleRateLookup[2] = 64000;
+ $AACsampleRateLookup[3] = 48000;
+ $AACsampleRateLookup[4] = 44100;
+ $AACsampleRateLookup[5] = 32000;
+ $AACsampleRateLookup[6] = 24000;
+ $AACsampleRateLookup[7] = 22050;
+ $AACsampleRateLookup[8] = 16000;
+ $AACsampleRateLookup[9] = 12000;
+ $AACsampleRateLookup[10] = 11025;
+ $AACsampleRateLookup[11] = 8000;
+ $AACsampleRateLookup[12] = 0;
+ $AACsampleRateLookup[13] = 0;
+ $AACsampleRateLookup[14] = 0;
+ $AACsampleRateLookup[15] = 0;
+ }
+ return (isset($AACsampleRateLookup[$samplerateid]) ? $AACsampleRateLookup[$samplerateid] : 'invalid');
+ }
+
+ function AACprofileLookup($profileid, $mpegversion) {
+ static $AACprofileLookup = array();
+ if (empty($AACprofileLookup)) {
+ $AACprofileLookup[2][0] = 'Main profile';
+ $AACprofileLookup[2][1] = 'Low Complexity profile (LC)';
+ $AACprofileLookup[2][2] = 'Scalable Sample Rate profile (SSR)';
+ $AACprofileLookup[2][3] = '(reserved)';
+ $AACprofileLookup[4][0] = 'AAC_MAIN';
+ $AACprofileLookup[4][1] = 'AAC_LC';
+ $AACprofileLookup[4][2] = 'AAC_SSR';
+ $AACprofileLookup[4][3] = 'AAC_LTP';
+ }
+ return (isset($AACprofileLookup[$mpegversion][$profileid]) ? $AACprofileLookup[$mpegversion][$profileid] : 'invalid');
+ }
+
+ function AACchannelCountCalculate($program_configs) {
+ $channels = 0;
+ for ($i = 0; $i < $program_configs['num_front_channel_elements']; $i++) {
+ $channels++;
+ if ($program_configs['front_element_is_cpe'][$i]) {
+ // each front element is channel pair (CPE = Channel Pair Element)
+ $channels++;
+ }
+ }
+ for ($i = 0; $i < $program_configs['num_side_channel_elements']; $i++) {
+ $channels++;
+ if ($program_configs['side_element_is_cpe'][$i]) {
+ // each side element is channel pair (CPE = Channel Pair Element)
+ $channels++;
+ }
+ }
+ for ($i = 0; $i < $program_configs['num_back_channel_elements']; $i++) {
+ $channels++;
+ if ($program_configs['back_element_is_cpe'][$i]) {
+ // each back element is channel pair (CPE = Channel Pair Element)
+ $channels++;
+ }
+ }
+ for ($i = 0; $i < $program_configs['num_lfe_channel_elements']; $i++) {
+ $channels++;
+ }
+ return $channels;
+ }
+
+}
+
+
+?> \ No newline at end of file
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-14 16:59:13 +0000