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.voc.php                                                 |
rlm@3: // | Module for analyzing Creative VOC Audio files.                       |
rlm@3: // | dependencies: NONE                                                   |
rlm@3: // +----------------------------------------------------------------------+
rlm@3: //
rlm@3: // $Id: module.audio.voc.php,v 1.3 2006/11/02 10:48:02 ah Exp $
rlm@3: 
rlm@3:         
rlm@3:         
rlm@3: class getid3_voc extends getid3_handler
rlm@3: {
rlm@3: 
rlm@3:     public function Analyze() {
rlm@3: 
rlm@3:         $getid3 = $this->getid3;
rlm@3:         
rlm@3:         $original_av_data_offset = $getid3->info['avdataoffset'];
rlm@3:         
rlm@3:         fseek($getid3->fp, $getid3->info['avdataoffset'], SEEK_SET);
rlm@3:         $voc_header= fread($getid3->fp, 26);
rlm@3: 
rlm@3:         // Magic bytes: 'Creative Voice File'
rlm@3: 
rlm@3:         $info_audio = &$getid3->info['audio'];
rlm@3:         $getid3->info['voc'] = array ();
rlm@3:         $info_voc = &$getid3->info['voc'];
rlm@3: 
rlm@3:         $getid3->info['fileformat']    = 'voc';
rlm@3:         $info_audio['dataformat']      = 'voc';
rlm@3:         $info_audio['bitrate_mode']    = 'cbr';
rlm@3:         $info_audio['lossless']        = true;
rlm@3:         $info_audio['channels']        = 1;         // might be overriden below
rlm@3:         $info_audio['bits_per_sample'] = 8;         // might be overriden below
rlm@3: 
rlm@3:         // byte #     Description
rlm@3:         // ------     ------------------------------------------
rlm@3:         // 00-12      'Creative Voice File'
rlm@3:         // 13         1A (eof to abort printing of file)
rlm@3:         // 14-15      Offset of first datablock in .voc file (std 1A 00 in Intel Notation)
rlm@3:         // 16-17      Version number (minor,major) (VOC-HDR puts 0A 01)
rlm@3:         // 18-19      2's Comp of Ver. # + 1234h (VOC-HDR puts 29 11)
rlm@3: 
rlm@3:         getid3_lib::ReadSequence('LittleEndian2Int', $info_voc['header'], $voc_header, 20,
rlm@3:             array (
rlm@3:                 'datablock_offset' => 2, 
rlm@3:                 'minor_version'    => 1, 
rlm@3:                 'major_version'    => 1  
rlm@3:             )
rlm@3:         );
rlm@3: 
rlm@3:         do {
rlm@3:             $block_offset = ftell($getid3->fp);
rlm@3:             $block_data   = fread($getid3->fp, 4);
rlm@3:             $block_type   = ord($block_data{0});
rlm@3:             $block_size   = getid3_lib::LittleEndian2Int(substr($block_data, 1, 3));
rlm@3:             $this_block   = array ();
rlm@3: 
rlm@3:             @$info_voc['blocktypes'][$block_type]++;
rlm@3:             
rlm@3:             switch ($block_type) {
rlm@3:                 
rlm@3:                 case 0:  // Terminator
rlm@3:                     // do nothing, we'll break out of the loop down below
rlm@3:                     break;
rlm@3: 
rlm@3:                 case 1:  // Sound data
rlm@3:                     $block_data .= fread($getid3->fp, 2);
rlm@3:                     if ($getid3->info['avdataoffset'] <= $original_av_data_offset) {
rlm@3:                         $getid3->info['avdataoffset'] = ftell($getid3->fp);
rlm@3:                     }
rlm@3:                     fseek($getid3->fp, $block_size - 2, SEEK_CUR);
rlm@3: 
rlm@3:                     getid3_lib::ReadSequence('LittleEndian2Int', $this_block, $block_data, 4,
rlm@3:                         array (
rlm@3:                             'sample_rate_id'   => 1,
rlm@3:                             'compression_type' => 1
rlm@3:                         )
rlm@3:                     );
rlm@3: 
rlm@3:                     $this_block['compression_name'] = getid3_voc::VOCcompressionTypeLookup($this_block['compression_type']);
rlm@3:                     if ($this_block['compression_type'] <= 3) {
rlm@3:                         $info_voc['compressed_bits_per_sample'] = (int)(str_replace('-bit', '', $this_block['compression_name']));
rlm@3:                     }
rlm@3: 
rlm@3:                     // Less accurate sample_rate calculation than the Extended block (#8) data (but better than nothing if Extended Block is not available)
rlm@3:                     if (empty($info_audio['sample_rate'])) {
rlm@3:                         // SR byte = 256 - (1000000 / sample_rate)
rlm@3:                         $info_audio['sample_rate'] = (int)floor((1000000 / (256 - $this_block['sample_rate_id'])) / $info_audio['channels']);
rlm@3:                     }
rlm@3:                     break;
rlm@3: 
rlm@3:                 case 2:  // Sound continue
rlm@3:                 case 3:  // Silence
rlm@3:                 case 4:  // Marker
rlm@3:                 case 6:  // Repeat
rlm@3:                 case 7:  // End repeat
rlm@3:                     // nothing useful, just skip
rlm@3:                     fseek($getid3->fp, $block_size, SEEK_CUR);
rlm@3:                     break;
rlm@3: 
rlm@3:                 case 8:  // Extended
rlm@3:                     $block_data .= fread($getid3->fp, 4);
rlm@3: 
rlm@3:                     //00-01  Time Constant:
rlm@3:                     //   Mono: 65536 - (256000000 / sample_rate)
rlm@3:                     // Stereo: 65536 - (256000000 / (sample_rate * 2))
rlm@3:                     getid3_lib::ReadSequence('LittleEndian2Int', $this_block, $block_data, 4,
rlm@3:                         array (
rlm@3:                             'time_constant' => 2, 
rlm@3:                             'pack_method'   => 1, 
rlm@3:                             'stereo'        => 1        
rlm@3:                         )
rlm@3:                     );
rlm@3:                     $this_block['stereo']      = (bool)$this_block['stereo'];
rlm@3:                     
rlm@3:                     $info_audio['channels']    = ($this_block['stereo'] ? 2 : 1);
rlm@3:                     $info_audio['sample_rate'] = (int)floor((256000000 / (65536 - $this_block['time_constant'])) / $info_audio['channels']);
rlm@3:                     break;
rlm@3: 
rlm@3:                 case 9:  // data block that supersedes blocks 1 and 8. Used for stereo, 16 bit
rlm@3:                     $block_data .= fread($getid3->fp, 12);
rlm@3:                     if ($getid3->info['avdataoffset'] <= $original_av_data_offset) {
rlm@3:                         $getid3->info['avdataoffset'] = ftell($getid3->fp);
rlm@3:                     }
rlm@3:                     fseek($getid3->fp, $block_size - 12, SEEK_CUR);
rlm@3: 
rlm@3:                     getid3_lib::ReadSequence('LittleEndian2Int', $this_block, $block_data, 4,
rlm@3:                         array (
rlm@3:                             'sample_rate'     => 4,
rlm@3:                             'bits_per_sample' => 1,
rlm@3:                             'channels'        => 1, 
rlm@3:                             'wFormat'         => 2 
rlm@3:                         )
rlm@3:                     );
rlm@3:                     
rlm@3:                     $this_block['compression_name'] = getid3_voc::VOCwFormatLookup($this_block['wFormat']);
rlm@3:                     if (getid3_voc::VOCwFormatActualBitsPerSampleLookup($this_block['wFormat'])) {
rlm@3:                         $info_voc['compressed_bits_per_sample'] = getid3_voc::VOCwFormatActualBitsPerSampleLookup($this_block['wFormat']);
rlm@3:                     }
rlm@3: 
rlm@3:                     $info_audio['sample_rate']     = $this_block['sample_rate'];
rlm@3:                     $info_audio['bits_per_sample'] = $this_block['bits_per_sample'];
rlm@3:                     $info_audio['channels']        = $this_block['channels'];
rlm@3:                     break;
rlm@3: 
rlm@3:                 default:
rlm@3:                     $getid3->warning('Unhandled block type "'.$block_type.'" at offset '.$block_offset);
rlm@3:                     fseek($getid3->fp, $block_size, SEEK_CUR);
rlm@3:                     break;
rlm@3:             }
rlm@3: 
rlm@3:             if (!empty($this_block)) {
rlm@3:                 $this_block['block_offset']  = $block_offset;
rlm@3:                 $this_block['block_size']    = $block_size;
rlm@3:                 $this_block['block_type_id'] = $block_type;
rlm@3:                 $info_voc['blocks'][] = $this_block;
rlm@3:             }
rlm@3: 
rlm@3:         } while (!feof($getid3->fp) && ($block_type != 0));
rlm@3: 
rlm@3:         // Terminator block doesn't have size field, so seek back 3 spaces
rlm@3:         fseek($getid3->fp, -3, SEEK_CUR);
rlm@3: 
rlm@3:         ksort($info_voc['blocktypes']);
rlm@3: 
rlm@3:         if (!empty($info_voc['compressed_bits_per_sample'])) {
rlm@3:             $getid3->info['playtime_seconds'] = (($getid3->info['avdataend'] - $getid3->info['avdataoffset']) * 8) / ($info_voc['compressed_bits_per_sample'] * $info_audio['channels'] * $info_audio['sample_rate']);
rlm@3:             $info_audio['bitrate'] = (($getid3->info['avdataend'] - $getid3->info['avdataoffset']) * 8) / $getid3->info['playtime_seconds'];
rlm@3:         }
rlm@3: 
rlm@3:         return true;
rlm@3:     }
rlm@3: 
rlm@3: 
rlm@3: 
rlm@3:     public static function VOCcompressionTypeLookup($index) {
rlm@3:         
rlm@3:         static $lookup = array (
rlm@3:             0 => '8-bit',
rlm@3:             1 => '4-bit',
rlm@3:             2 => '2.6-bit',
rlm@3:             3 => '2-bit'
rlm@3:         );
rlm@3:         return (isset($lookup[$index]) ? $lookup[$index] : 'Multi DAC ('.($index - 3).') channels');
rlm@3:     }
rlm@3: 
rlm@3: 
rlm@3: 
rlm@3:     public static function VOCwFormatLookup($index) {
rlm@3:         
rlm@3:         static $lookup = array (
rlm@3:             0x0000 => '8-bit unsigned PCM',
rlm@3:             0x0001 => 'Creative 8-bit to 4-bit ADPCM',
rlm@3:             0x0002 => 'Creative 8-bit to 3-bit ADPCM',
rlm@3:             0x0003 => 'Creative 8-bit to 2-bit ADPCM',
rlm@3:             0x0004 => '16-bit signed PCM',
rlm@3:             0x0006 => 'CCITT a-Law',
rlm@3:             0x0007 => 'CCITT u-Law',
rlm@3:             0x2000 => 'Creative 16-bit to 4-bit ADPCM'
rlm@3:         );
rlm@3:         return (isset($lookup[$index]) ? $lookup[$index] : false);
rlm@3:     }
rlm@3: 
rlm@3: 
rlm@3: 
rlm@3:     public static function VOCwFormatActualBitsPerSampleLookup($index) {
rlm@3:         
rlm@3:         static $lookup = array (
rlm@3:             0x0000 => 8,
rlm@3:             0x0001 => 4,
rlm@3:             0x0002 => 3,
rlm@3:             0x0003 => 2,
rlm@3:             0x0004 => 16,
rlm@3:             0x0006 => 8,
rlm@3:             0x0007 => 8,
rlm@3:             0x2000 => 4
rlm@3:         );
rlm@3:         return (isset($lookup[$index]) ? $lookup[$index] : false);
rlm@3:     }
rlm@3: 
rlm@3: }
rlm@3: 
rlm@3: 
rlm@3: ?>