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