<?php
/////////////////////////////////////////////////////////////////
/// getID3() by James Heinrich <info@getid3.org> //
// available at http://getid3.sourceforge.net ///
// or http://www.getid3.org ///
/////////////////////////////////////////////////////////////////
// //
// getid3.voc.php - part of getID3() //
// See getid3.readme.txt for more details //
// //
/////////////////////////////////////////////////////////////////
function getVOCheaderFilepointer(&$fd, &$ThisFileInfo) {
$OriginalAVdataOffset = $ThisFileInfo['avdataoffset'];
fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);
$VOCheader = fread($fd, 26);
if (substr($VOCheader, 0, 19) != 'Creative Voice File') {
$ThisFileInfo['error'] .= "\n".'Expecting "Creative Voice File" at offset '.$ThisFileInfo['avdataoffset'].', found "'.substr($VOCheader, 0, 19).'"';
return false;
}
$ThisFileInfo['fileformat'] = 'voc';
$ThisFileInfo['audio']['dataformat'] = 'voc';
$ThisFileInfo['audio']['bitrate_mode'] = 'cbr';
$ThisFileInfo['audio']['channels'] = 1; // might be overriden below
$ThisFileInfo['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)
$ThisFileInfo['voc']['header']['datablock_offset'] = LittleEndian2Int(substr($VOCheader, 20, 2));
$ThisFileInfo['voc']['header']['minor_version'] = LittleEndian2Int(substr($VOCheader, 22, 1));
$ThisFileInfo['voc']['header']['major_version'] = LittleEndian2Int(substr($VOCheader, 23, 1));
do {
$BlockOffset = ftell($fd);
$BlockData = fread($fd, 4);
$BlockType = LittleEndian2Int(substr($BlockData, 0, 1));
$BlockSize = LittleEndian2Int(substr($BlockData, 1, 3));
$ThisBlock = array();
switch ($BlockType) {
case 0: // Terminator
// do nothing, we'll break out of the loop down below
break;
case 1: // Sound data
$BlockData .= fread($fd, 2);
if ($ThisFileInfo['avdataoffset'] <= $OriginalAVdataOffset) {
$ThisFileInfo['avdataoffset'] = ftell($fd);
}
fseek($fd, $BlockSize - 2, SEEK_CUR);
$ThisBlock['sample_rate_id'] = LittleEndian2Int(substr($BlockData, 4, 1));
$ThisBlock['compression_type'] = LittleEndian2Int(substr($BlockData, 5, 1));
$ThisBlock['compression_name'] = VOCcompressionTypeLookup($ThisBlock['compression_type']);
if ($ThisBlock['compression_type'] <= 3) {
$ThisFileInfo['voc']['compressed_bits_per_sample'] = CastAsInt(str_replace('-bit', '', $ThisBlock['compression_name']));
}
if (empty($ThisFileInfo['audio']['sample_rate'])) {
// Less accurate than the Extended block (#8) data
// SR byte = 256-(1000000/sample_rate)
$ThisFileInfo['audio']['sample_rate'] = trunc((1000000 / (256 - $ThisBlock['sample_rate_id'])) / $ThisFileInfo['audio']['channels']);
}
break;
case 2: // Sound continue
case 3: // Silence
case 4: // Marker
case 6: // Repeat
case 7: // End repeat
// nothing useful, just skip
fseek($fd, $BlockSize, SEEK_CUR);
break;
case 8: // Extended
$BlockData .= fread($fd, 4);
//00-01 Time Constant:
// Mono: 65536 - (256000000 / sample_rate)
// Stereo: 65536 - (256000000 / (sample_rate * 2))
$ThisBlock['time_constant'] = LittleEndian2Int(substr($BlockData, 4, 2));
$ThisBlock['pack_method'] = LittleEndian2Int(substr($BlockData, 6, 1));
$ThisBlock['stereo'] = (bool) LittleEndian2Int(substr($BlockData, 7, 1));
$ThisFileInfo['audio']['channels'] = ($ThisBlock['stereo'] ? 2 : 1);
$ThisFileInfo['audio']['sample_rate'] = trunc((256000000 / (65536 - $ThisBlock['time_constant'])) / $ThisFileInfo['audio']['channels']);
break;
case 9: // data block that supersedes blocks 1 and 8. Used for stereo, 16 bit
$BlockData .= fread($fd, 12);
if ($ThisFileInfo['avdataoffset'] <= $OriginalAVdataOffset) {
$ThisFileInfo['avdataoffset'] = ftell($fd);
}
fseek($fd, $BlockSize - 12, SEEK_CUR);
$ThisBlock['sample_rate'] = LittleEndian2Int(substr($BlockData, 4, 4));
$ThisBlock['bits_per_sample'] = LittleEndian2Int(substr($BlockData, 8, 1));
$ThisBlock['channels'] = LittleEndian2Int(substr($BlockData, 9, 1));
$ThisBlock['wFormat'] = LittleEndian2Int(substr($BlockData, 10, 2));
$ThisBlock['compression_name'] = VOCwFormatLookup($ThisBlock['wFormat']);
if (VOCwFormatActualBitsPerSampleLookup($ThisBlock['wFormat'])) {
$ThisFileInfo['voc']['compressed_bits_per_sample'] = VOCwFormatActualBitsPerSampleLookup($ThisBlock['wFormat']);
}
$ThisFileInfo['audio']['sample_rate'] = $ThisBlock['sample_rate'];
$ThisFileInfo['audio']['bits_per_sample'] = $ThisBlock['bits_per_sample'];
$ThisFileInfo['audio']['channels'] = $ThisBlock['channels'];
break;
default:
$ThisFileInfo['warning'] .= "\n".'Unhandled block type "'.$BlockType.'" at offset '.$BlockOffset;
fseek($fd, $BlockSize, SEEK_CUR);
break;
}
if (!empty($ThisBlock)) {
$ThisBlock['block_offset'] = $BlockOffset;
$ThisBlock['block_size'] = $BlockSize;
$ThisBlock['block_type_id'] = $BlockType;
$ThisFileInfo['voc']['blocks'][] = $ThisBlock;
}
} while (!feof($fd) && ($BlockType != 0));
// Terminator block doesn't have size field, so seek back 3 spaces
fseek($fd, -3, SEEK_CUR);
if (!empty($ThisFileInfo['voc']['compressed_bits_per_sample'])) {
$ThisFileInfo['playtime_seconds'] = (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8) / ($ThisFileInfo['voc']['compressed_bits_per_sample'] * $ThisFileInfo['audio']['channels'] * $ThisFileInfo['audio']['sample_rate']);
$ThisFileInfo['audio']['bitrate'] = (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8) / $ThisFileInfo['playtime_seconds'];
}
return true;
}
function VOCcompressionTypeLookup($index) {
static $VOCcompressionTypeLookup = array();
if (empty($VOCcompressionTypeLookup)) {
$VOCcompressionTypeLookup[0] = '8-bit';
$VOCcompressionTypeLookup[1] = '4-bit';
$VOCcompressionTypeLookup[2] = '2.6-bit';
$VOCcompressionTypeLookup[3] = '2-bit';
}
return (isset($VOCcompressionTypeLookup[$index]) ? $VOCcompressionTypeLookup[$index] : 'Multi DAC ('.($index - 3).') channels');
}
function VOCwFormatLookup($index) {
static $VOCwFormatLookup = array();
if (empty($VOCwFormatLookup)) {
$VOCwFormatLookup[0x0000] = '8-bit unsigned PCM';
$VOCwFormatLookup[0x0001] = 'Creative 8-bit to 4-bit ADPCM';
$VOCwFormatLookup[0x0002] = 'Creative 8-bit to 3-bit ADPCM';
$VOCwFormatLookup[0x0003] = 'Creative 8-bit to 2-bit ADPCM';
$VOCwFormatLookup[0x0004] = '16-bit signed PCM';
$VOCwFormatLookup[0x0006] = 'CCITT a-Law';
$VOCwFormatLookup[0x0007] = 'CCITT u-Law';
$VOCwFormatLookup[0x2000] = 'Creative 16-bit to 4-bit ADPCM';
}
return (isset($VOCwFormatLookup[$index]) ? $VOCwFormatLookup[$index] : false);
}
function VOCwFormatActualBitsPerSampleLookup($index) {
static $VOCwFormatLookup = array();
if (empty($VOCwFormatLookup)) {
$VOCwFormatLookup[0x0000] = 8;
$VOCwFormatLookup[0x0001] = 4;
$VOCwFormatLookup[0x0002] = 3;
$VOCwFormatLookup[0x0003] = 2;
$VOCwFormatLookup[0x0004] = 16;
$VOCwFormatLookup[0x0006] = 8;
$VOCwFormatLookup[0x0007] = 8;
$VOCwFormatLookup[0x2000] = 4;
}
return (isset($VOCwFormatLookup[$index]) ? $VOCwFormatLookup[$index] : false);
}
?>