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ampache/modules/getid3/module.audio.avr.php

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7.8 KiB
PHP

<?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.avr.php |
// | Module for analyzing AVR audio files |
// | dependencies: NONE |
// +----------------------------------------------------------------------+
//
// $Id: module.audio.avr.php,v 1.2 2006/11/02 10:48:01 ah Exp $
class getid3_avr extends getid3_handler
{
public function Analyze() {
$getid3 = $this->getid3;
// http://cui.unige.ch/OSG/info/AudioFormats/ap11.html
// http://www.btinternet.com/~AnthonyJ/Atari/programming/avr_format.html
// offset type length name comments
// ---------------------------------------------------------------------
// 0 char 4 ID format ID == "2BIT"
// 4 char 8 name sample name (unused space filled with 0)
// 12 short 1 mono/stereo 0=mono, -1 (0xFFFF)=stereo
// With stereo, samples are alternated,
// the first voice is the left :
// (LRLRLRLRLRLRLRLRLR...)
// 14 short 1 resolution 8, 12 or 16 (bits)
// 16 short 1 signed or not 0=unsigned, -1 (0xFFFF)=signed
// 18 short 1 loop or not 0=no loop, -1 (0xFFFF)=loop on
// 20 short 1 MIDI note 0xFFnn, where 0 <= nn <= 127
// 0xFFFF means "no MIDI note defined"
// 22 byte 1 Replay speed Frequence in the Replay software
// 0=5.485 Khz, 1=8.084 Khz, 2=10.971 Khz,
// 3=16.168 Khz, 4=21.942 Khz, 5=32.336 Khz
// 6=43.885 Khz, 7=47.261 Khz
// -1 (0xFF)=no defined Frequence
// 23 byte 3 sample rate in Hertz
// 26 long 1 size in bytes (2 * bytes in stereo)
// 30 long 1 loop begin 0 for no loop
// 34 long 1 loop size equal to 'size' for no loop
// 38 short 2 Reserved, MIDI keyboard split */
// 40 short 2 Reserved, sample compression */
// 42 short 2 Reserved */
// 44 char 20; Additional filename space, used if (name[7] != 0)
// 64 byte 64 user data
// 128 bytes ? sample data (12 bits samples are coded on 16 bits:
// 0000 xxxx xxxx xxxx)
// ---------------------------------------------------------------------
// Note that all values are in motorola (big-endian) format, and that long is
// assumed to be 4 bytes, and short 2 bytes.
// When reading the samples, you should handle both signed and unsigned data,
// and be prepared to convert 16->8 bit, or mono->stereo if needed. To convert
// 8-bit data between signed/unsigned just add 127 to the sample values.
// Simularly for 16-bit data you should add 32769
// Magic bytes: '2BIT'
$getid3->info['avr'] = array ();
$info_avr = &$getid3->info['avr'];
$getid3->info['fileformat'] = 'avr';
$info_avr['raw']['magic'] = '2BIT';
fseek($getid3->fp, $getid3->info['avdataoffset'], SEEK_SET);
$avr_header = fread($getid3->fp, 128);
$getid3->info['avdataoffset'] += 128;
$info_avr['sample_name'] = rtrim(substr($avr_header, 4, 8));
$info_avr['raw']['mono'] = getid3_lib::BigEndian2Int(substr($avr_header, 12, 2));
$info_avr['bits_per_sample'] = getid3_lib::BigEndian2Int(substr($avr_header, 14, 2));
$info_avr['raw']['signed'] = getid3_lib::BigEndian2Int(substr($avr_header, 16, 2));
$info_avr['raw']['loop'] = getid3_lib::BigEndian2Int(substr($avr_header, 18, 2));
$info_avr['raw']['midi'] = getid3_lib::BigEndian2Int(substr($avr_header, 20, 2));
$info_avr['raw']['replay_freq'] = getid3_lib::BigEndian2Int(substr($avr_header, 22, 1));
$info_avr['sample_rate'] = getid3_lib::BigEndian2Int(substr($avr_header, 23, 3));
$info_avr['sample_length'] = getid3_lib::BigEndian2Int(substr($avr_header, 26, 4));
$info_avr['loop_start'] = getid3_lib::BigEndian2Int(substr($avr_header, 30, 4));
$info_avr['loop_end'] = getid3_lib::BigEndian2Int(substr($avr_header, 34, 4));
$info_avr['midi_split'] = getid3_lib::BigEndian2Int(substr($avr_header, 38, 2));
$info_avr['sample_compression'] = getid3_lib::BigEndian2Int(substr($avr_header, 40, 2));
$info_avr['reserved'] = getid3_lib::BigEndian2Int(substr($avr_header, 42, 2));
$info_avr['sample_name_extra'] = rtrim(substr($avr_header, 44, 20));
$info_avr['comment'] = rtrim(substr($avr_header, 64, 64));
$info_avr['flags']['stereo'] = (($info_avr['raw']['mono'] == 0) ? false : true);
$info_avr['flags']['signed'] = (($info_avr['raw']['signed'] == 0) ? false : true);
$info_avr['flags']['loop'] = (($info_avr['raw']['loop'] == 0) ? false : true);
$info_avr['midi_notes'] = array ();
if (($info_avr['raw']['midi'] & 0xFF00) != 0xFF00) {
$info_avr['midi_notes'][] = ($info_avr['raw']['midi'] & 0xFF00) >> 8;
}
if (($info_avr['raw']['midi'] & 0x00FF) != 0x00FF) {
$info_avr['midi_notes'][] = ($info_avr['raw']['midi'] & 0x00FF);
}
if (($getid3->info['avdataend'] - $getid3->info['avdataoffset']) != ($info_avr['sample_length'] * (($info_avr['bits_per_sample'] == 8) ? 1 : 2))) {
$getid3->warning('Probable truncated file: expecting '.($info_avr['sample_length'] * (($info_avr['bits_per_sample'] == 8) ? 1 : 2)).' bytes of audio data, found '.($getid3->info['avdataend'] - $getid3->info['avdataoffset']));
}
$getid3->info['audio']['dataformat'] = 'avr';
$getid3->info['audio']['lossless'] = true;
$getid3->info['audio']['bitrate_mode'] = 'cbr';
$getid3->info['audio']['bits_per_sample'] = $info_avr['bits_per_sample'];
$getid3->info['audio']['sample_rate'] = $info_avr['sample_rate'];
$getid3->info['audio']['channels'] = ($info_avr['flags']['stereo'] ? 2 : 1);
$getid3->info['playtime_seconds'] = ($info_avr['sample_length'] / $getid3->info['audio']['channels']) / $info_avr['sample_rate'];
$getid3->info['audio']['bitrate'] = ($info_avr['sample_length'] * (($info_avr['bits_per_sample'] == 8) ? 8 : 16)) / $getid3->info['playtime_seconds'];
return true;
}
}
?>