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

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  Classes of Karl Holz  >  WaldScan  >  includes/getid3/module.audio.avr.php  >  Download  
File: includes/getid3/module.audio.avr.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: 1 year ago
Size: 6,964 bytes
 

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<?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.avr.php                                        //
// module for analyzing AVR Audio files                        //
// dependencies: NONE                                          //
//                                                            ///
/////////////////////////////////////////////////////////////////


class getid3_avr extends getid3_handler
{

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

        
// 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

        
$info['fileformat'] = 'avr';

        
fseek($this->getid3->fp$info['avdataoffset'], SEEK_SET);
        
$AVRheader fread($this->getid3->fp128);

        
$info['avr']['raw']['magic'] = substr($AVRheader,  0,  4);
        
$magic '2BIT';
        if (
$info['avr']['raw']['magic'] != $magic) {
            
$info['error'][] = 'Expecting "'.getid3_lib::PrintHexBytes($magic).'" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes($info['avr']['raw']['magic']).'"';
            unset(
$info['fileformat']);
            unset(
$info['avr']);
            return 
false;
        }
        
$info['avdataoffset'] += 128;

        
$info['avr']['sample_name']        =         rtrim(substr($AVRheader,  4,  8));
        
$info['avr']['raw']['mono']        = getid3_lib::BigEndian2Int(substr($AVRheader12,  2));
        
$info['avr']['bits_per_sample']    = getid3_lib::BigEndian2Int(substr($AVRheader14,  2));
        
$info['avr']['raw']['signed']      = getid3_lib::BigEndian2Int(substr($AVRheader16,  2));
        
$info['avr']['raw']['loop']        = getid3_lib::BigEndian2Int(substr($AVRheader18,  2));
        
$info['avr']['raw']['midi']        = getid3_lib::BigEndian2Int(substr($AVRheader20,  2));
        
$info['avr']['raw']['replay_freq'] = getid3_lib::BigEndian2Int(substr($AVRheader22,  1));
        
$info['avr']['sample_rate']        = getid3_lib::BigEndian2Int(substr($AVRheader23,  3));
        
$info['avr']['sample_length']      = getid3_lib::BigEndian2Int(substr($AVRheader26,  4));
        
$info['avr']['loop_start']         = getid3_lib::BigEndian2Int(substr($AVRheader30,  4));
        
$info['avr']['loop_end']           = getid3_lib::BigEndian2Int(substr($AVRheader34,  4));
        
$info['avr']['midi_split']         = getid3_lib::BigEndian2Int(substr($AVRheader38,  2));
        
$info['avr']['sample_compression'] = getid3_lib::BigEndian2Int(substr($AVRheader40,  2));
        
$info['avr']['reserved']           = getid3_lib::BigEndian2Int(substr($AVRheader42,  2));
        
$info['avr']['sample_name_extra']  =         rtrim(substr($AVRheader4420));
        
$info['avr']['comment']            =         rtrim(substr($AVRheader6464));

        
$info['avr']['flags']['stereo'] = (($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 ((
$info['avdataend'] - $info['avdataoffset']) != ($info['avr']['sample_length'] * (($info['avr']['bits_per_sample'] == 8) ? 2))) {
            
$info['warning'][] = 'Probable truncated file: expecting '.($info['avr']['sample_length'] * (($info['avr']['bits_per_sample'] == 8) ? 2)).' bytes of audio data, found '.($info['avdataend'] - $info['avdataoffset']);
        }

        
$info['audio']['dataformat']      = 'avr';
        
$info['audio']['lossless']        = true;
        
$info['audio']['bitrate_mode']    = 'cbr';
        
$info['audio']['bits_per_sample'] = $info['avr']['bits_per_sample'];
        
$info['audio']['sample_rate']     = $info['avr']['sample_rate'];
        
$info['audio']['channels']        = ($info['avr']['flags']['stereo'] ? 1);
        
$info['playtime_seconds']         = ($info['avr']['sample_length'] / $info['audio']['channels']) / $info['avr']['sample_rate'];
        
$info['audio']['bitrate']         = ($info['avr']['sample_length'] * (($info['avr']['bits_per_sample'] == 8) ? 16)) / $info['playtime_seconds'];


        return 
true;
    }

}


?>