<?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.au.php                                         //
// module for analyzing AU files                               //
// dependencies: NONE                                          //
//                                                            ///
/////////////////////////////////////////////////////////////////


class getid3_au extends getid3_handler
{

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

		fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
		$AUheader  = fread($this->getid3->fp, 8);

		$magic = '.snd';
		if (substr($AUheader, 0, 4) != $magic) {
			$info['error'][] = 'Expecting "'.getid3_lib::PrintHexBytes($magic).'" (".snd") at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes(substr($AUheader, 0, 4)).'"';
			return false;
		}

		// shortcut
		$info['au'] = array();
		$thisfile_au        = &$info['au'];

		$info['fileformat']            = 'au';
		$info['audio']['dataformat']   = 'au';
		$info['audio']['bitrate_mode'] = 'cbr';
		$thisfile_au['encoding']               = 'ISO-8859-1';

		$thisfile_au['header_length']   = getid3_lib::BigEndian2Int(substr($AUheader,  4, 4));
		$AUheader .= fread($this->getid3->fp, $thisfile_au['header_length'] - 8);
		$info['avdataoffset'] += $thisfile_au['header_length'];

		$thisfile_au['data_size']             = getid3_lib::BigEndian2Int(substr($AUheader,  8, 4));
		$thisfile_au['data_format_id']        = getid3_lib::BigEndian2Int(substr($AUheader, 12, 4));
		$thisfile_au['sample_rate']           = getid3_lib::BigEndian2Int(substr($AUheader, 16, 4));
		$thisfile_au['channels']              = getid3_lib::BigEndian2Int(substr($AUheader, 20, 4));
		$thisfile_au['comments']['comment'][] =                      trim(substr($AUheader, 24));

		$thisfile_au['data_format'] = $this->AUdataFormatNameLookup($thisfile_au['data_format_id']);
		$thisfile_au['used_bits_per_sample'] = $this->AUdataFormatUsedBitsPerSampleLookup($thisfile_au['data_format_id']);
		if ($thisfile_au['bits_per_sample'] = $this->AUdataFormatBitsPerSampleLookup($thisfile_au['data_format_id'])) {
			$info['audio']['bits_per_sample'] = $thisfile_au['bits_per_sample'];
		} else {
			unset($thisfile_au['bits_per_sample']);
		}

		$info['audio']['sample_rate']  = $thisfile_au['sample_rate'];
		$info['audio']['channels']     = $thisfile_au['channels'];

		if (($info['avdataoffset'] + $thisfile_au['data_size']) > $info['avdataend']) {
			$info['warning'][] = 'Possible truncated file - expecting "'.$thisfile_au['data_size'].'" bytes of audio data, only found '.($info['avdataend'] - $info['avdataoffset']).' bytes"';
		}

		$info['playtime_seconds'] = $thisfile_au['data_size'] / ($thisfile_au['sample_rate'] * $thisfile_au['channels'] * ($thisfile_au['used_bits_per_sample'] / 8));
		$info['audio']['bitrate'] = ($thisfile_au['data_size'] * 8) / $info['playtime_seconds'];

		return true;
	}

	public function AUdataFormatNameLookup($id) {
		static $AUdataFormatNameLookup = array(
			0  => 'unspecified format',
			1  => '8-bit mu-law',
			2  => '8-bit linear',
			3  => '16-bit linear',
			4  => '24-bit linear',
			5  => '32-bit linear',
			6  => 'floating-point',
			7  => 'double-precision float',
			8  => 'fragmented sampled data',
			9  => 'SUN_FORMAT_NESTED',
			10 => 'DSP program',
			11 => '8-bit fixed-point',
			12 => '16-bit fixed-point',
			13 => '24-bit fixed-point',
			14 => '32-bit fixed-point',

			16 => 'non-audio display data',
			17 => 'SND_FORMAT_MULAW_SQUELCH',
			18 => '16-bit linear with emphasis',
			19 => '16-bit linear with compression',
			20 => '16-bit linear with emphasis + compression',
			21 => 'Music Kit DSP commands',
			22 => 'SND_FORMAT_DSP_COMMANDS_SAMPLES',
			23 => 'CCITT g.721 4-bit ADPCM',
			24 => 'CCITT g.722 ADPCM',
			25 => 'CCITT g.723 3-bit ADPCM',
			26 => 'CCITT g.723 5-bit ADPCM',
			27 => 'A-Law 8-bit'
		);
		return (isset($AUdataFormatNameLookup[$id]) ? $AUdataFormatNameLookup[$id] : false);
	}

	public function AUdataFormatBitsPerSampleLookup($id) {
		static $AUdataFormatBitsPerSampleLookup = array(
			1  => 8,
			2  => 8,
			3  => 16,
			4  => 24,
			5  => 32,
			6  => 32,
			7  => 64,

			11 => 8,
			12 => 16,
			13 => 24,
			14 => 32,

			18 => 16,
			19 => 16,
			20 => 16,

			23 => 16,

			25 => 16,
			26 => 16,
			27 => 8
		);
		return (isset($AUdataFormatBitsPerSampleLookup[$id]) ? $AUdataFormatBitsPerSampleLookup[$id] : false);
	}

	public function AUdataFormatUsedBitsPerSampleLookup($id) {
		static $AUdataFormatUsedBitsPerSampleLookup = array(
			1  => 8,
			2  => 8,
			3  => 16,
			4  => 24,
			5  => 32,
			6  => 32,
			7  => 64,

			11 => 8,
			12 => 16,
			13 => 24,
			14 => 32,

			18 => 16,
			19 => 16,
			20 => 16,

			23 => 4,

			25 => 3,
			26 => 5,
			27 => 8,
		);
		return (isset($AUdataFormatUsedBitsPerSampleLookup[$id]) ? $AUdataFormatUsedBitsPerSampleLookup[$id] : false);
	}

}
