vendor/getid3/module.audio.lpac.php

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<?php

/////////////////////////////////////////////////////////////////
/// getID3() by James Heinrich <info@getid3.org>               //
//  available at https://github.com/JamesHeinrich/getID3       //
//            or https://www.getid3.org                        //
//            or http://getid3.sourceforge.net                 //
//  see readme.txt for more details                            //
/////////////////////////////////////////////////////////////////
//                                                             //
// module.audio.lpac.php                                       //
// module for analyzing LPAC Audio files                       //
// dependencies: module.audio-video.riff.php                   //
//                                                            ///
/////////////////////////////////////////////////////////////////

if (!defined('GETID3_INCLUDEPATH')) { // prevent path-exposing attacks that access modules directly on public webservers
	exit;
}
getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio-video.riff.php', __FILE__, true);

class getid3_lpac extends getid3_handler
{
	/**
	 * @return bool
	 */
	public function Analyze() {
		$info = &$this->getid3->info;

		$this->fseek($info['avdataoffset']);
		$LPACheader = $this->fread(14);
		$StreamMarker = substr($LPACheader, 0, 4);
		if ($StreamMarker != 'LPAC') {
			$this->error('Expected "LPAC" at offset '.$info['avdataoffset'].', found "'.$StreamMarker.'"');
			return false;
		}
		$info['avdataoffset'] += 14;

		$info['fileformat']            = 'lpac';
		$info['audio']['dataformat']   = 'lpac';
		$info['audio']['lossless']     = true;
		$info['audio']['bitrate_mode'] = 'vbr';

		$info['lpac']['file_version'] = getid3_lib::BigEndian2Int(substr($LPACheader,  4, 1));
		$flags['audio_type']                  = getid3_lib::BigEndian2Int(substr($LPACheader,  5, 1));
		$info['lpac']['total_samples']= getid3_lib::BigEndian2Int(substr($LPACheader,  6, 4));
		$flags['parameters']                  = getid3_lib::BigEndian2Int(substr($LPACheader, 10, 4));

		$info['lpac']['flags']['is_wave'] = (bool) ($flags['audio_type'] & 0x40);
		$info['lpac']['flags']['stereo']  = (bool) ($flags['audio_type'] & 0x04);
		$info['lpac']['flags']['24_bit']  = (bool) ($flags['audio_type'] & 0x02);
		$info['lpac']['flags']['16_bit']  = (bool) ($flags['audio_type'] & 0x01);

		if ($info['lpac']['flags']['24_bit'] && $info['lpac']['flags']['16_bit']) {
			$this->warning('24-bit and 16-bit flags cannot both be set');
		}

		$info['lpac']['flags']['fast_compress']             =  (bool) ($flags['parameters'] & 0x40000000);
		$info['lpac']['flags']['random_access']             =  (bool) ($flags['parameters'] & 0x08000000);
		$info['lpac']['block_length']                       = pow(2, (($flags['parameters'] & 0x07000000) >> 24)) * 256;