yetangitu/ampache
1
0
Fork 0
mirror of https://github.com/Yetangitu/ampache synced 2025-10-05 02:39:47 +02:00
Code Issues Releases Wiki Activity
ampache/modules/getid3/module.audio.aac_adif.php

311 lines
No EOL
15 KiB
PHP
Raw Blame History

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