1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/e2gallerypro/e2upload/Backend/Assets/getid3/module.audio.aac_adts.php	Mon Feb 22 08:02:39 2010 -0500
     1.3 @@ -0,0 +1,282 @@
     1.4 +<?php
     1.5 +// +----------------------------------------------------------------------+
     1.6 +// | PHP version 5                                                        |
     1.7 +// +----------------------------------------------------------------------+
     1.8 +// | Copyright (c) 2002-2006 James Heinrich, Allan Hansen                 |
     1.9 +// +----------------------------------------------------------------------+
    1.10 +// | This source file is subject to version 2 of the GPL license,         |
    1.11 +// | that is bundled with this package in the file license.txt and is     |
    1.12 +// | available through the world-wide-web at the following url:           |
    1.13 +// | http://www.gnu.org/copyleft/gpl.html                                 |
    1.14 +// +----------------------------------------------------------------------+
    1.15 +// | getID3() - http://getid3.sourceforge.net or http://www.getid3.org    |
    1.16 +// +----------------------------------------------------------------------+
    1.17 +// | Authors: James Heinrich <infoØgetid3*org>                            |
    1.18 +// |          Allan Hansen <ahØartemis*dk>                                |
    1.19 +// +----------------------------------------------------------------------+
    1.20 +// | module.audio.aac_adts.php                                            |
    1.21 +// | Module for analyzing AAC files with ADTS header.                     |
    1.22 +// | dependencies: NONE                                                   |
    1.23 +// +----------------------------------------------------------------------+
    1.24 +//
    1.25 +// $Id: module.audio.aac_adts.php,v 1.4 2006/11/02 10:48:01 ah Exp $
    1.26 +
    1.27 +        
    1.28 +        
    1.29 +class getid3_aac_adts extends getid3_handler
    1.30 +{
    1.31 +
    1.32 +    public $option_max_frames_to_scan   = 1000000;
    1.33 +    public $option_return_extended_info = false;
    1.34 +    
    1.35 +
    1.36 +    private $decbin_cache;
    1.37 +    private $bitrate_cache;
    1.38 +    
    1.39 +
    1.40 +
    1.41 +    public function __construct(getID3 $getid3) {
    1.42 +        
    1.43 +        parent::__construct($getid3);
    1.44 +    
    1.45 +        // Populate bindec_cache
    1.46 +        for ($i = 0; $i < 256; $i++) {
    1.47 +                $this->decbin_cache[chr($i)] = str_pad(decbin($i), 8, '0', STR_PAD_LEFT);
    1.48 +        }
    1.49 +        
    1.50 +        // Init cache
    1.51 +        $this->bitrate_cache = array ();
    1.52 +        
    1.53 +        // Fast scanning?
    1.54 +        if (!$getid3->option_accurate_results) {
    1.55 +            $this->option_max_frames_to_scan = 200;
    1.56 +            $getid3->warning('option_accurate_results set to false - bitrate and playing time are not accurate.');
    1.57 +        }
    1.58 +    }
    1.59 +    
    1.60 +        
    1.61 +
    1.62 +    public function Analyze() {
    1.63 +        
    1.64 +        $getid3 = $this->getid3;
    1.65 +
    1.66 +        // based loosely on code from AACfile by Jurgen Faul  <jfaulØgmx.de>
    1.67 +        // http://jfaul.de/atl  or  http://j-faul.virtualave.net/atl/atl.html
    1.68 +
    1.69 +
    1.70 +        // http://faac.sourceforge.net/wiki/index.php?page=ADTS
    1.71 +
    1.72 +        // * ADTS Fixed Header: these don't change from frame to frame
    1.73 +        // syncword                                       12    always: '111111111111'
    1.74 +        // ID                                              1    0: MPEG-4, 1: MPEG-2
    1.75 +        // layer                                           2    always: '00'
    1.76 +        // protection_absent                               1
    1.77 +        // profile                                         2
    1.78 +        // sampling_frequency_index                        4
    1.79 +        // private_bit                                     1
    1.80 +        // channel_configuration                           3
    1.81 +        // original/copy                                   1
    1.82 +        // home                                            1
    1.83 +        // emphasis                                        2    only if ID == 0 (ie MPEG-4)
    1.84 +
    1.85 +        // * ADTS Variable Header: these can change from frame to frame
    1.86 +        // copyright_identification_bit                    1
    1.87 +        // copyright_identification_start                  1
    1.88 +        // aac_frame_length                               13    length of the frame including header (in bytes)
    1.89 +        // adts_buffer_fullness                           11    0x7FF indicates VBR
    1.90 +        // no_raw_data_blocks_in_frame                     2
    1.91 +
    1.92 +        // * ADTS Error check
    1.93 +        // crc_check                                      16    only if protection_absent == 0
    1.94 +
    1.95 +        $getid3->info['aac']['header'] = array () ;
    1.96 +        $info_aac        = &$getid3->info['aac'];
    1.97 +        $info_aac_header = & $info_aac['header'];
    1.98 +
    1.99 +        $byte_offset  = $frame_number = 0;
   1.100 +
   1.101 +        while (true) {
   1.102 +            
   1.103 +            // Breaks out when end-of-file encountered, or invalid data found,
   1.104 +            // or MaxFramesToScan frames have been scanned
   1.105 +
   1.106 +            fseek($getid3->fp, $byte_offset, SEEK_SET);
   1.107 +
   1.108 +            // First get substring
   1.109 +            $sub_string = fread($getid3->fp, 10);
   1.110 +            $sub_string_length = strlen($sub_string);
   1.111 +            if ($sub_string_length != 10) {
   1.112 +                throw new getid3_exception('Failed to read 10 bytes at offset '.(ftell($getid3->fp) - $sub_string_length).' (only read '.$sub_string_length.' bytes)');
   1.113 +            }
   1.114 +
   1.115 +            // Initialise $aac_header_bitstream
   1.116 +            $aac_header_bitstream = '';
   1.117 +
   1.118 +            // Loop thru substring chars
   1.119 +            for ($i = 0; $i < 10; $i++) {
   1.120 +                $aac_header_bitstream .= $this->decbin_cache[$sub_string[$i]];
   1.121 +            }
   1.122 +            
   1.123 +            $sync_test  = bindec(substr($aac_header_bitstream, 0, 12));
   1.124 +            $bit_offset = 12;
   1.125 +            
   1.126 +            if ($sync_test != 0x0FFF) {
   1.127 +                throw new getid3_exception('Synch pattern (0x0FFF) not found at offset '.(ftell($getid3->fp) - 10).' (found 0x0'.strtoupper(dechex($sync_test)).' instead)');
   1.128 +            }
   1.129 +
   1.130 +            // Only gather info once - this takes time to do 1000 times!
   1.131 +            if ($frame_number > 0) {
   1.132 +
   1.133 +                // MPEG-4: 20,  // MPEG-2: 18
   1.134 +                $bit_offset += $aac_header_bitstream[$bit_offset] ? 18 : 20;
   1.135 +            } 
   1.136 +        
   1.137 +            // Gather info for first frame only - this takes time to do 1000 times!
   1.138 +            else {
   1.139 +
   1.140 +                $info_aac['header_type']             = 'ADTS';
   1.141 +                $info_aac_header['synch']            = $sync_test;
   1.142 +                $getid3->info['fileformat']          = 'aac';
   1.143 +                $getid3->info['audio']['dataformat'] = 'aac';
   1.144 +
   1.145 +                $info_aac_header['mpeg_version']     = $aac_header_bitstream{$bit_offset++} == '0' ? 4 : 2;
   1.146 +                $info_aac_header['layer']            = bindec(substr($aac_header_bitstream, $bit_offset, 2));
   1.147 +                $bit_offset += 2;
   1.148 +                
   1.149 +                if ($info_aac_header['layer'] != 0) {
   1.150 +                    throw new getid3_exception('Layer error - expected 0x00, found 0x'.dechex($info_aac_header['layer']).' instead');
   1.151 +                }
   1.152 +                
   1.153 +                $info_aac_header['crc_present'] = $aac_header_bitstream{$bit_offset++} == '0' ? true : false;
   1.154 +                
   1.155 +                $info_aac_header['profile_id'] = bindec(substr($aac_header_bitstream, $bit_offset, 2));
   1.156 +                $bit_offset += 2;
   1.157 +                
   1.158 +                $info_aac_header['profile_text'] = getid3_aac_adts::AACprofileLookup($info_aac_header['profile_id'], $info_aac_header['mpeg_version']);
   1.159 +
   1.160 +                $info_aac_header['sample_frequency_index'] = bindec(substr($aac_header_bitstream, $bit_offset, 4));
   1.161 +                $bit_offset += 4;
   1.162 +                
   1.163 +                $info_aac_header['sample_frequency'] = getid3_aac_adts::AACsampleRateLookup($info_aac_header['sample_frequency_index']);
   1.164 +                
   1.165 +                $getid3->info['audio']['sample_rate'] = $info_aac_header['sample_frequency'];
   1.166 +
   1.167 +                $info_aac_header['private'] = $aac_header_bitstream{$bit_offset++} == 1;
   1.168 +                
   1.169 +                $info_aac_header['channel_configuration'] = $getid3->info['audio']['channels'] = bindec(substr($aac_header_bitstream, $bit_offset, 3));
   1.170 +                $bit_offset += 3;
   1.171 +                
   1.172 +                $info_aac_header['original'] = $aac_header_bitstream{$bit_offset++} == 1;
   1.173 +                $info_aac_header['home']     = $aac_header_bitstream{$bit_offset++} == 1;
   1.174 +
   1.175 +                if ($info_aac_header['mpeg_version'] == 4) {
   1.176 +                    $info_aac_header['emphasis']  = bindec(substr($aac_header_bitstream, $bit_offset, 2));
   1.177 +                    $bit_offset += 2;
   1.178 +                }
   1.179 +
   1.180 +                if ($this->option_return_extended_info) {
   1.181 +
   1.182 +                    $info_aac[$frame_number]['copyright_id_bit']   = $aac_header_bitstream{$bit_offset++} == 1;
   1.183 +                    $info_aac[$frame_number]['copyright_id_start'] = $aac_header_bitstream{$bit_offset++} == 1;
   1.184 +
   1.185 +                }  else {
   1.186 +                    $bit_offset += 2;
   1.187 +                }
   1.188 +            }
   1.189 +
   1.190 +            $frame_length = bindec(substr($aac_header_bitstream, $bit_offset, 13));
   1.191 +
   1.192 +            if (!isset($this->bitrate_cache[$frame_length])) {
   1.193 +                $this->bitrate_cache[$frame_length] = ($info_aac_header['sample_frequency'] / 1024) * $frame_length * 8;
   1.194 +            }
   1.195 +            @$info_aac['bitrate_distribution'][$this->bitrate_cache[$frame_length]]++;
   1.196 +
   1.197 +            $info_aac[$frame_number]['aac_frame_length']     = $frame_length;
   1.198 +            $bit_offset += 13;
   1.199 +            
   1.200 +            $info_aac[$frame_number]['adts_buffer_fullness'] = bindec(substr($aac_header_bitstream, $bit_offset, 11));
   1.201 +            $bit_offset += 11;
   1.202 +            
   1.203 +            $getid3->info['audio']['bitrate_mode'] = ($info_aac[$frame_number]['adts_buffer_fullness'] == 0x07FF) ? 'vbr' : 'cbr';
   1.204 +            
   1.205 +            $info_aac[$frame_number]['num_raw_data_blocks']  = bindec(substr($aac_header_bitstream, $bit_offset, 2));
   1.206 +            $bit_offset += 2;
   1.207 +
   1.208 +            if ($info_aac_header['crc_present']) {
   1.209 +                $bit_offset += 16;
   1.210 +            }
   1.211 +
   1.212 +            if (!$this->option_return_extended_info) {
   1.213 +                unset($info_aac[$frame_number]);
   1.214 +            }
   1.215 +
   1.216 +            $byte_offset += $frame_length;
   1.217 +            if ((++$frame_number < $this->option_max_frames_to_scan) && (($byte_offset + 10) < $getid3->info['avdataend'])) {
   1.218 +
   1.219 +                // keep scanning
   1.220 +
   1.221 +            } else {
   1.222 +
   1.223 +                $info_aac['frames']    = $frame_number;
   1.224 +                $getid3->info['playtime_seconds'] = ($getid3->info['avdataend'] / $byte_offset) * (($frame_number * 1024) / $info_aac_header['sample_frequency']);  // (1 / % of file scanned) * (samples / (samples/sec)) = seconds
   1.225 +                $getid3->info['audio']['bitrate'] = (($getid3->info['avdataend'] - $getid3->info['avdataoffset']) * 8) / $getid3->info['playtime_seconds'];
   1.226 +                ksort($info_aac['bitrate_distribution']);
   1.227 +
   1.228 +                $getid3->info['audio']['encoder_options'] = $info_aac['header_type'].' '.$info_aac_header['profile_text'];
   1.229 +
   1.230 +                return true;
   1.231 +            }
   1.232 +        }
   1.233 +    }
   1.234 +
   1.235 +    
   1.236 +    
   1.237 +    public static function AACsampleRateLookup($samplerate_id) {
   1.238 +        
   1.239 +        static $lookup = array (
   1.240 +            0  => 96000,
   1.241 +            1  => 88200,
   1.242 +            2  => 64000,
   1.243 +            3  => 48000,
   1.244 +            4  => 44100,
   1.245 +            5  => 32000,
   1.246 +            6  => 24000,
   1.247 +            7  => 22050,
   1.248 +            8  => 16000,
   1.249 +            9  => 12000,
   1.250 +            10 => 11025,
   1.251 +            11 => 8000,
   1.252 +            12 => 0,
   1.253 +            13 => 0,
   1.254 +            14 => 0,
   1.255 +            15 => 0
   1.256 +        );
   1.257 +        return (isset($lookup[$samplerate_id]) ? $lookup[$samplerate_id] : 'invalid');
   1.258 +    }
   1.259 +
   1.260 +
   1.261 +
   1.262 +    public static function AACprofileLookup($profile_id, $mpeg_version) {
   1.263 +        
   1.264 +        static $lookup = array (
   1.265 +            2 => array ( 
   1.266 +                0 => 'Main profile',
   1.267 +                1 => 'Low Complexity profile (LC)',
   1.268 +                2 => 'Scalable Sample Rate profile (SSR)',
   1.269 +                3 => '(reserved)'
   1.270 +            ),            
   1.271 +            4 => array (
   1.272 +                0 => 'AAC_MAIN',
   1.273 +                1 => 'AAC_LC',
   1.274 +                2 => 'AAC_SSR',
   1.275 +                3 => 'AAC_LTP'
   1.276 +            )
   1.277 +        );
   1.278 +        return (isset($lookup[$mpeg_version][$profile_id]) ? $lookup[$mpeg_version][$profile_id] : 'invalid');
   1.279 +    }
   1.280 +
   1.281 +
   1.282 +}
   1.283 +
   1.284 +
   1.285 +?>
   1.286 \ No newline at end of file