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File: includes/getid3/module.audio.voc.php

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  Classes of Karl Holz  >  WaldScan  >  includes/getid3/module.audio.voc.php  >  Download  
File: includes/getid3/module.audio.voc.php
Role: Auxiliary script
Content type: text/plain
Description: getID3 dependency
Class: WaldScan
Scan directories for files with certain extensions
Author: By
Last change:
Date: 2 years ago
Size: 8,365 bytes
 

Contents

Class file image Download
<?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.voc.php //
// module for analyzing Creative VOC Audio files //
// dependencies: NONE //
// ///
/////////////////////////////////////////////////////////////////


class getid3_voc extends getid3_handler
{

    function
Analyze() {
       
$info = &$this->getid3->info;

       
$OriginalAVdataOffset = $info['avdataoffset'];
       
fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
       
$VOCheader = fread($this->getid3->fp, 26);

       
$magic = 'Creative Voice File';
        if (
substr($VOCheader, 0, 19) != $magic) {
           
$info['error'][] = 'Expecting "'.getid3_lib::PrintHexBytes($magic).'" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes(substr($VOCheader, 0, 19)).'"';
            return
false;
        }

       
// shortcuts
       
$thisfile_audio = &$info['audio'];
       
$info['voc'] = array();
       
$thisfile_voc = &$info['voc'];

       
$info['fileformat'] = 'voc';
       
$thisfile_audio['dataformat'] = 'voc';
       
$thisfile_audio['bitrate_mode'] = 'cbr';
       
$thisfile_audio['lossless'] = true;
       
$thisfile_audio['channels'] = 1; // might be overriden below
       
$thisfile_audio['bits_per_sample'] = 8; // might be overriden below

        // byte # Description
        // ------ ------------------------------------------
        // 00-12 'Creative Voice File'
        // 13 1A (eof to abort printing of file)
        // 14-15 Offset of first datablock in .voc file (std 1A 00 in Intel Notation)
        // 16-17 Version number (minor,major) (VOC-HDR puts 0A 01)
        // 18-19 2's Comp of Ver. # + 1234h (VOC-HDR puts 29 11)

       
$thisfile_voc['header']['datablock_offset'] = getid3_lib::LittleEndian2Int(substr($VOCheader, 20, 2));
       
$thisfile_voc['header']['minor_version'] = getid3_lib::LittleEndian2Int(substr($VOCheader, 22, 1));
       
$thisfile_voc['header']['major_version'] = getid3_lib::LittleEndian2Int(substr($VOCheader, 23, 1));

        do {

           
$BlockOffset = ftell($this->getid3->fp);
           
$BlockData = fread($this->getid3->fp, 4);
           
$BlockType = ord($BlockData{0});
           
$BlockSize = getid3_lib::LittleEndian2Int(substr($BlockData, 1, 3));
           
$ThisBlock = array();

           
getid3_lib::safe_inc($thisfile_voc['blocktypes'][$BlockType], 1);
            switch (
$BlockType) {
                case
0: // Terminator
                    // do nothing, we'll break out of the loop down below
                   
break;

                case
1: // Sound data
                   
$BlockData .= fread($this->getid3->fp, 2);
                    if (
$info['avdataoffset'] <= $OriginalAVdataOffset) {
                       
$info['avdataoffset'] = ftell($this->getid3->fp);
                    }
                   
fseek($this->getid3->fp, $BlockSize - 2, SEEK_CUR);

                   
$ThisBlock['sample_rate_id'] = getid3_lib::LittleEndian2Int(substr($BlockData, 4, 1));
                   
$ThisBlock['compression_type'] = getid3_lib::LittleEndian2Int(substr($BlockData, 5, 1));

                   
$ThisBlock['compression_name'] = $this->VOCcompressionTypeLookup($ThisBlock['compression_type']);
                    if (
$ThisBlock['compression_type'] <= 3) {
                       
$thisfile_voc['compressed_bits_per_sample'] = getid3_lib::CastAsInt(str_replace('-bit', '', $ThisBlock['compression_name']));
                    }

                   
// Less accurate sample_rate calculation than the Extended block (#8) data (but better than nothing if Extended Block is not available)
                   
if (empty($thisfile_audio['sample_rate'])) {
                       
// SR byte = 256 - (1000000 / sample_rate)
                       
$thisfile_audio['sample_rate'] = getid3_lib::trunc((1000000 / (256 - $ThisBlock['sample_rate_id'])) / $thisfile_audio['channels']);
                    }
                    break;

                case
2: // Sound continue
               
case 3: // Silence
               
case 4: // Marker
               
case 6: // Repeat
               
case 7: // End repeat
                    // nothing useful, just skip
                   
fseek($this->getid3->fp, $BlockSize, SEEK_CUR);
                    break;

                case
8: // Extended
                   
$BlockData .= fread($this->getid3->fp, 4);

                   
//00-01 Time Constant:
                    // Mono: 65536 - (256000000 / sample_rate)
                    // Stereo: 65536 - (256000000 / (sample_rate * 2))
                   
$ThisBlock['time_constant'] = getid3_lib::LittleEndian2Int(substr($BlockData, 4, 2));
                   
$ThisBlock['pack_method'] = getid3_lib::LittleEndian2Int(substr($BlockData, 6, 1));
                   
$ThisBlock['stereo'] = (bool) getid3_lib::LittleEndian2Int(substr($BlockData, 7, 1));

                   
$thisfile_audio['channels'] = ($ThisBlock['stereo'] ? 2 : 1);
                   
$thisfile_audio['sample_rate'] = getid3_lib::trunc((256000000 / (65536 - $ThisBlock['time_constant'])) / $thisfile_audio['channels']);
                    break;

                case
9: // data block that supersedes blocks 1 and 8. Used for stereo, 16 bit
                   
$BlockData .= fread($this->getid3->fp, 12);
                    if (
$info['avdataoffset'] <= $OriginalAVdataOffset) {
                       
$info['avdataoffset'] = ftell($this->getid3->fp);
                    }
                   
fseek($this->getid3->fp, $BlockSize - 12, SEEK_CUR);

                   
$ThisBlock['sample_rate'] = getid3_lib::LittleEndian2Int(substr($BlockData, 4, 4));
                   
$ThisBlock['bits_per_sample'] = getid3_lib::LittleEndian2Int(substr($BlockData, 8, 1));
                   
$ThisBlock['channels'] = getid3_lib::LittleEndian2Int(substr($BlockData, 9, 1));
                   
$ThisBlock['wFormat'] = getid3_lib::LittleEndian2Int(substr($BlockData, 10, 2));

                   
$ThisBlock['compression_name'] = $this->VOCwFormatLookup($ThisBlock['wFormat']);
                    if (
$this->VOCwFormatActualBitsPerSampleLookup($ThisBlock['wFormat'])) {
                       
$thisfile_voc['compressed_bits_per_sample'] = $this->VOCwFormatActualBitsPerSampleLookup($ThisBlock['wFormat']);
                    }

                   
$thisfile_audio['sample_rate'] = $ThisBlock['sample_rate'];
                   
$thisfile_audio['bits_per_sample'] = $ThisBlock['bits_per_sample'];
                   
$thisfile_audio['channels'] = $ThisBlock['channels'];
                    break;

                default:
                   
$info['warning'][] = 'Unhandled block type "'.$BlockType.'" at offset '.$BlockOffset;
                   
fseek($this->getid3->fp, $BlockSize, SEEK_CUR);
                    break;
            }

            if (!empty(
$ThisBlock)) {
               
$ThisBlock['block_offset'] = $BlockOffset;
               
$ThisBlock['block_size'] = $BlockSize;
               
$ThisBlock['block_type_id'] = $BlockType;
               
$thisfile_voc['blocks'][] = $ThisBlock;
            }

        } while (!
feof($this->getid3->fp) && ($BlockType != 0));

       
// Terminator block doesn't have size field, so seek back 3 spaces
       
fseek($this->getid3->fp, -3, SEEK_CUR);

       
ksort($thisfile_voc['blocktypes']);

        if (!empty(
$thisfile_voc['compressed_bits_per_sample'])) {
           
$info['playtime_seconds'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / ($thisfile_voc['compressed_bits_per_sample'] * $thisfile_audio['channels'] * $thisfile_audio['sample_rate']);
           
$thisfile_audio['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
        }

        return
true;
    }

    function
VOCcompressionTypeLookup($index) {
        static
$VOCcompressionTypeLookup = array(
           
0 => '8-bit',
           
1 => '4-bit',
           
2 => '2.6-bit',
           
3 => '2-bit'
       
);
        return (isset(
$VOCcompressionTypeLookup[$index]) ? $VOCcompressionTypeLookup[$index] : 'Multi DAC ('.($index - 3).') channels');
    }

    function
VOCwFormatLookup($index) {
        static
$VOCwFormatLookup = array(
           
0x0000 => '8-bit unsigned PCM',
           
0x0001 => 'Creative 8-bit to 4-bit ADPCM',
           
0x0002 => 'Creative 8-bit to 3-bit ADPCM',
           
0x0003 => 'Creative 8-bit to 2-bit ADPCM',
           
0x0004 => '16-bit signed PCM',
           
0x0006 => 'CCITT a-Law',
           
0x0007 => 'CCITT u-Law',
           
0x2000 => 'Creative 16-bit to 4-bit ADPCM'
       
);
        return (isset(
$VOCwFormatLookup[$index]) ? $VOCwFormatLookup[$index] : false);
    }

    function
VOCwFormatActualBitsPerSampleLookup($index) {
        static
$VOCwFormatLookup = array(
           
0x0000 => 8,
           
0x0001 => 4,
           
0x0002 => 3,
           
0x0003 => 2,
           
0x0004 => 16,
           
0x0006 => 8,
           
0x0007 => 8,
           
0x2000 => 4
       
);
        return (isset(
$VOCwFormatLookup[$index]) ? $VOCwFormatLookup[$index] : false);
    }

}


?>