rlm@3: <?php
rlm@3: // +----------------------------------------------------------------------+
rlm@3: // | PHP version 5 |
rlm@3: // +----------------------------------------------------------------------+
rlm@3: // | Copyright (c) 2002-2006 James Heinrich, Allan Hansen |
rlm@3: // +----------------------------------------------------------------------+
rlm@3: // | This source file is subject to version 2 of the GPL license, |
rlm@3: // | that is bundled with this package in the file license.txt and is |
rlm@3: // | available through the world-wide-web at the following url: |
rlm@3: // | http://www.gnu.org/copyleft/gpl.html |
rlm@3: // +----------------------------------------------------------------------+
rlm@3: // | getID3() - http://getid3.sourceforge.net or http://www.getid3.org |
rlm@3: // +----------------------------------------------------------------------+
rlm@3: // | Authors: James Heinrich <infoØgetid3*org> |
rlm@3: // | Allan Hansen <ahØartemis*dk> |
rlm@3: // +----------------------------------------------------------------------+
rlm@3: // | module.audio.aac_adif.php |
rlm@3: // | Module for analyzing AAC files with ADIF header. |
rlm@3: // | dependencies: NONE |
rlm@3: // +----------------------------------------------------------------------+
rlm@3: //
rlm@3: // $Id: module.audio.aac_adif.php,v 1.3 2006/11/02 10:48:00 ah Exp $
rlm@3:
rlm@3:
rlm@3:
rlm@3: class getid3_aac_adif extends getid3_handler
rlm@3: {
rlm@3:
rlm@3: public function Analyze() {
rlm@3:
rlm@3: $getid3 = $this->getid3;
rlm@3:
rlm@3: // http://faac.sourceforge.net/wiki/index.php?page=ADIF
rlm@3: // http://libmpeg.org/mpeg4/doc/w2203tfs.pdf
rlm@3: // adif_header() {
rlm@3: // adif_id 32
rlm@3: // copyright_id_present 1
rlm@3: // if( copyright_id_present )
rlm@3: // copyright_id 72
rlm@3: // original_copy 1
rlm@3: // home 1
rlm@3: // bitstream_type 1
rlm@3: // bitrate 23
rlm@3: // num_program_config_elements 4
rlm@3: // for (i = 0; i < num_program_config_elements + 1; i++ ) {
rlm@3: // if( bitstream_type == '0' )
rlm@3: // adif_buffer_fullness 20
rlm@3: // program_config_element()
rlm@3: // }
rlm@3: // }
rlm@3:
rlm@3:
rlm@3: $getid3->info['fileformat'] = 'aac';
rlm@3: $getid3->info['audio']['dataformat'] = 'aac';
rlm@3: $getid3->info['audio']['lossless'] = false;
rlm@3:
rlm@3: $getid3->info['aac']['header'] = array () ;
rlm@3: $info_aac = &$getid3->info['aac'];
rlm@3: $info_aac_header = & $info_aac['header'];
rlm@3:
rlm@3: fseek($getid3->fp, $getid3->info['avdataoffset'], SEEK_SET);
rlm@3: $aac_header_bitstream = getid3_lib::BigEndian2Bin(fread($getid3->fp, 1024));
rlm@3:
rlm@3: $info_aac['header_type'] = 'ADIF';
rlm@3: $info_aac_header['mpeg_version'] = 4;
rlm@3: $bit_offset = 32;
rlm@3:
rlm@3: $info_aac_header['copyright'] = $aac_header_bitstream{$bit_offset++} == '1';
rlm@3: if ($info_aac_header['copyright']) {
rlm@3: $info_aac_header['copyright_id'] = getid3_aac_adif::Bin2String(substr($aac_header_bitstream, $bit_offset, 72));
rlm@3: $bit_offset += 72;
rlm@3: }
rlm@3:
rlm@3: $info_aac_header['original_copy'] = $aac_header_bitstream{$bit_offset++} == '1';
rlm@3: $info_aac_header['home'] = $aac_header_bitstream{$bit_offset++} == '1';
rlm@3: $info_aac_header['is_vbr'] = $aac_header_bitstream{$bit_offset++} == '1';
rlm@3:
rlm@3: if ($info_aac_header['is_vbr']) {
rlm@3: $getid3->info['audio']['bitrate_mode'] = 'vbr';
rlm@3: $info_aac_header['bitrate_max'] = bindec(substr($aac_header_bitstream, $bit_offset, 23));
rlm@3: $bit_offset += 23;
rlm@3: }
rlm@3: else {
rlm@3: $getid3->info['audio']['bitrate_mode'] = 'cbr';
rlm@3: $info_aac_header['bitrate'] = bindec(substr($aac_header_bitstream, $bit_offset, 23));
rlm@3: $bit_offset += 23;
rlm@3: $getid3->info['audio']['bitrate'] = $info_aac_header['bitrate'];
rlm@3: }
rlm@3:
rlm@3: $info_aac_header['num_program_configs'] = 1 + bindec(substr($aac_header_bitstream, $bit_offset, 4));
rlm@3: $bit_offset += 4;
rlm@3:
rlm@3: for ($i = 0; $i < $info_aac_header['num_program_configs']; $i++) {
rlm@3:
rlm@3: // http://www.audiocoding.com/wiki/index.php?page=program_config_element
rlm@3:
rlm@3: // buffer_fullness 20
rlm@3:
rlm@3: // element_instance_tag 4
rlm@3: // object_type 2
rlm@3: // sampling_frequency_index 4
rlm@3: // num_front_channel_elements 4
rlm@3: // num_side_channel_elements 4
rlm@3: // num_back_channel_elements 4
rlm@3: // num_lfe_channel_elements 2
rlm@3: // num_assoc_data_elements 3
rlm@3: // num_valid_cc_elements 4
rlm@3: // mono_mixdown_present 1
rlm@3: // mono_mixdown_element_number 4 if mono_mixdown_present == 1
rlm@3: // stereo_mixdown_present 1
rlm@3: // stereo_mixdown_element_number 4 if stereo_mixdown_present == 1
rlm@3: // matrix_mixdown_idx_present 1
rlm@3: // matrix_mixdown_idx 2 if matrix_mixdown_idx_present == 1
rlm@3: // pseudo_surround_enable 1 if matrix_mixdown_idx_present == 1
rlm@3: // for (i = 0; i < num_front_channel_elements; i++) {
rlm@3: // front_element_is_cpe[i] 1
rlm@3: // front_element_tag_select[i] 4
rlm@3: // }
rlm@3: // for (i = 0; i < num_side_channel_elements; i++) {
rlm@3: // side_element_is_cpe[i] 1
rlm@3: // side_element_tag_select[i] 4
rlm@3: // }
rlm@3: // for (i = 0; i < num_back_channel_elements; i++) {
rlm@3: // back_element_is_cpe[i] 1
rlm@3: // back_element_tag_select[i] 4
rlm@3: // }
rlm@3: // for (i = 0; i < num_lfe_channel_elements; i++) {
rlm@3: // lfe_element_tag_select[i] 4
rlm@3: // }
rlm@3: // for (i = 0; i < num_assoc_data_elements; i++) {
rlm@3: // assoc_data_element_tag_select[i] 4
rlm@3: // }
rlm@3: // for (i = 0; i < num_valid_cc_elements; i++) {
rlm@3: // cc_element_is_ind_sw[i] 1
rlm@3: // valid_cc_element_tag_select[i] 4
rlm@3: // }
rlm@3: // byte_alignment() VAR
rlm@3: // comment_field_bytes 8
rlm@3: // for (i = 0; i < comment_field_bytes; i++) {
rlm@3: // comment_field_data[i] 8
rlm@3: // }
rlm@3:
rlm@3: $info_aac['program_configs'][$i] = array ();
rlm@3: $info_aac_program_configs_i = &$info_aac['program_configs'][$i];
rlm@3:
rlm@3: if (!$info_aac_header['is_vbr']) {
rlm@3: $info_aac_program_configs_i['buffer_fullness'] = bindec(substr($aac_header_bitstream, $bit_offset, 20));
rlm@3: $bit_offset += 20;
rlm@3: }
rlm@3:
rlm@3: $info_aac_program_configs_i['element_instance_tag'] = bindec(substr($aac_header_bitstream, $bit_offset, 4));
rlm@3: $info_aac_program_configs_i['object_type'] = bindec(substr($aac_header_bitstream, $bit_offset + 4, 2));
rlm@3: $info_aac_program_configs_i['sampling_frequency_index'] = bindec(substr($aac_header_bitstream, $bit_offset + 6, 4));
rlm@3: $info_aac_program_configs_i['num_front_channel_elements'] = bindec(substr($aac_header_bitstream, $bit_offset + 10, 4));
rlm@3: $info_aac_program_configs_i['num_side_channel_elements'] = bindec(substr($aac_header_bitstream, $bit_offset + 14, 4));
rlm@3: $info_aac_program_configs_i['num_back_channel_elements'] = bindec(substr($aac_header_bitstream, $bit_offset + 18, 4));
rlm@3: $info_aac_program_configs_i['num_lfe_channel_elements'] = bindec(substr($aac_header_bitstream, $bit_offset + 22, 2));
rlm@3: $info_aac_program_configs_i['num_assoc_data_elements'] = bindec(substr($aac_header_bitstream, $bit_offset + 24, 3));
rlm@3: $info_aac_program_configs_i['num_valid_cc_elements'] = bindec(substr($aac_header_bitstream, $bit_offset + 27, 4));
rlm@3: $bit_offset += 31;
rlm@3:
rlm@3: $info_aac_program_configs_i['mono_mixdown_present'] = $aac_header_bitstream{$bit_offset++} == 1;
rlm@3: if ($info_aac_program_configs_i['mono_mixdown_present']) {
rlm@3: $info_aac_program_configs_i['mono_mixdown_element_number'] = bindec(substr($aac_header_bitstream, $bit_offset, 4));
rlm@3: $bit_offset += 4;
rlm@3: }
rlm@3:
rlm@3: $info_aac_program_configs_i['stereo_mixdown_present'] = $aac_header_bitstream{$bit_offset++} == 1;
rlm@3: if ($info_aac_program_configs_i['stereo_mixdown_present']) {
rlm@3: $info_aac_program_configs_i['stereo_mixdown_element_number'] = bindec(substr($aac_header_bitstream, $bit_offset, 4));
rlm@3: $bit_offset += 4;
rlm@3: }
rlm@3:
rlm@3: $info_aac_program_configs_i['matrix_mixdown_idx_present'] = $aac_header_bitstream{$bit_offset++} == 1;
rlm@3: if ($info_aac_program_configs_i['matrix_mixdown_idx_present']) {
rlm@3: $info_aac_program_configs_i['matrix_mixdown_idx'] = bindec(substr($aac_header_bitstream, $bit_offset, 2));
rlm@3: $bit_offset += 2;
rlm@3: $info_aac_program_configs_i['pseudo_surround_enable'] = $aac_header_bitstream{$bit_offset++} == 1;
rlm@3: }
rlm@3:
rlm@3: for ($j = 0; $j < $info_aac_program_configs_i['num_front_channel_elements']; $j++) {
rlm@3: $info_aac_program_configs_i['front_element_is_cpe'][$j] = $aac_header_bitstream{$bit_offset++} == 1;
rlm@3: $info_aac_program_configs_i['front_element_tag_select'][$j] = bindec(substr($aac_header_bitstream, $bit_offset, 4));
rlm@3: $bit_offset += 4;
rlm@3: }
rlm@3: for ($j = 0; $j < $info_aac_program_configs_i['num_side_channel_elements']; $j++) {
rlm@3: $info_aac_program_configs_i['side_element_is_cpe'][$j] = $aac_header_bitstream{$bit_offset++} == 1;
rlm@3: $info_aac_program_configs_i['side_element_tag_select'][$j] = bindec(substr($aac_header_bitstream, $bit_offset, 4));
rlm@3: $bit_offset += 4;
rlm@3: }
rlm@3: for ($j = 0; $j < $info_aac_program_configs_i['num_back_channel_elements']; $j++) {
rlm@3: $info_aac_program_configs_i['back_element_is_cpe'][$j] = $aac_header_bitstream{$bit_offset++} == 1;
rlm@3: $info_aac_program_configs_i['back_element_tag_select'][$j] = bindec(substr($aac_header_bitstream, $bit_offset, 4));
rlm@3: $bit_offset += 4;
rlm@3: }
rlm@3: for ($j = 0; $j < $info_aac_program_configs_i['num_lfe_channel_elements']; $j++) {
rlm@3: $info_aac_program_configs_i['lfe_element_tag_select'][$j] = bindec(substr($aac_header_bitstream, $bit_offset, 4));
rlm@3: $bit_offset += 4;
rlm@3: }
rlm@3: for ($j = 0; $j < $info_aac_program_configs_i['num_assoc_data_elements']; $j++) {
rlm@3: $info_aac_program_configs_i['assoc_data_element_tag_select'][$j] = bindec(substr($aac_header_bitstream, $bit_offset, 4));
rlm@3: $bit_offset += 4;
rlm@3: }
rlm@3: for ($j = 0; $j < $info_aac_program_configs_i['num_valid_cc_elements']; $j++) {
rlm@3: $info_aac_program_configs_i['cc_element_is_ind_sw'][$j] = $aac_header_bitstream{$bit_offset++} == 1;
rlm@3: $info_aac_program_configs_i['valid_cc_element_tag_select'][$j] = bindec(substr($aac_header_bitstream, $bit_offset, 4));
rlm@3: $bit_offset += 4;
rlm@3: }
rlm@3:
rlm@3: $bit_offset = ceil($bit_offset / 8) * 8;
rlm@3:
rlm@3: $info_aac_program_configs_i['comment_field_bytes'] = bindec(substr($aac_header_bitstream, $bit_offset, 8));
rlm@3: $bit_offset += 8;
rlm@3:
rlm@3: $info_aac_program_configs_i['comment_field'] = getid3_aac_adif::Bin2String(substr($aac_header_bitstream, $bit_offset, 8 * $info_aac_program_configs_i['comment_field_bytes']));
rlm@3: $bit_offset += 8 * $info_aac_program_configs_i['comment_field_bytes'];
rlm@3:
rlm@3: $info_aac_header['profile_text'] = getid3_aac_adif::AACprofileLookup($info_aac_program_configs_i['object_type'], $info_aac_header['mpeg_version']);
rlm@3: $info_aac_program_configs_i['sampling_frequency'] = $getid3->info['audio']['sample_rate'] = getid3_aac_adif::AACsampleRateLookup($info_aac_program_configs_i['sampling_frequency_index']);
rlm@3: $getid3->info['audio']['channels'] = getid3_aac_adif::AACchannelCountCalculate($info_aac_program_configs_i);
rlm@3:
rlm@3: if ($info_aac_program_configs_i['comment_field']) {
rlm@3: $info_aac['comments'][] = $info_aac_program_configs_i['comment_field'];
rlm@3: }
rlm@3: }
rlm@3:
rlm@3: $getid3->info['playtime_seconds'] = (($getid3->info['avdataend'] - $getid3->info['avdataoffset']) * 8) / $getid3->info['audio']['bitrate'];
rlm@3: $getid3->info['audio']['encoder_options'] = $info_aac['header_type'].' '.$info_aac_header['profile_text'];
rlm@3:
rlm@3: return true;
rlm@3: }
rlm@3:
rlm@3:
rlm@3:
rlm@3: public static function Bin2String($bin_string) {
rlm@3: // return 'hi' for input of '0110100001101001'
rlm@3: $string = '';
rlm@3: $bin_string_reversed = strrev($bin_string);
rlm@3: for ($i = 0; $i < strlen($bin_string_reversed); $i += 8) {
rlm@3: $string = chr(bindec(strrev(substr($bin_string_reversed, $i, 8)))).$string;
rlm@3: }
rlm@3: return $string;
rlm@3: }
rlm@3:
rlm@3:
rlm@3:
rlm@3: public static function AACsampleRateLookup($samplerate_id) {
rlm@3:
rlm@3: static $lookup = array (
rlm@3: 0 => 96000,
rlm@3: 1 => 88200,
rlm@3: 2 => 64000,
rlm@3: 3 => 48000,
rlm@3: 4 => 44100,
rlm@3: 5 => 32000,
rlm@3: 6 => 24000,
rlm@3: 7 => 22050,
rlm@3: 8 => 16000,
rlm@3: 9 => 12000,
rlm@3: 10 => 11025,
rlm@3: 11 => 8000,
rlm@3: 12 => 0,
rlm@3: 13 => 0,
rlm@3: 14 => 0,
rlm@3: 15 => 0
rlm@3: );
rlm@3: return (isset($lookup[$samplerate_id]) ? $lookup[$samplerate_id] : 'invalid');
rlm@3: }
rlm@3:
rlm@3:
rlm@3:
rlm@3: public static function AACprofileLookup($profile_id, $mpeg_version) {
rlm@3:
rlm@3: static $lookup = array (
rlm@3: 2 => array (
rlm@3: 0 => 'Main profile',
rlm@3: 1 => 'Low Complexity profile (LC)',
rlm@3: 2 => 'Scalable Sample Rate profile (SSR)',
rlm@3: 3 => '(reserved)'
rlm@3: ),
rlm@3: 4 => array (
rlm@3: 0 => 'AAC_MAIN',
rlm@3: 1 => 'AAC_LC',
rlm@3: 2 => 'AAC_SSR',
rlm@3: 3 => 'AAC_LTP'
rlm@3: )
rlm@3: );
rlm@3: return (isset($lookup[$mpeg_version][$profile_id]) ? $lookup[$mpeg_version][$profile_id] : 'invalid');
rlm@3: }
rlm@3:
rlm@3:
rlm@3:
rlm@3: public static function AACchannelCountCalculate($program_configs) {
rlm@3:
rlm@3: $channels = 0;
rlm@3:
rlm@3: foreach (array ('front', 'side', 'back') as $placement) {
rlm@3: for ($i = 0; $i < $program_configs['num_'.$placement.'_channel_elements']; $i++) {
rlm@3:
rlm@3: // Each element is channel pair (CPE = Channel Pair Element)
rlm@3: $channels += 1 + ($program_configs[$placement.'_element_is_cpe'][$i] ? 1 : 0);
rlm@3: }
rlm@3: }
rlm@3:
rlm@3: return $channels + $program_configs['num_lfe_channel_elements'];
rlm@3: }
rlm@3:
rlm@3: }
rlm@3:
rlm@3:
rlm@3: ?>