getid3_handler

			if (isset($this->info['replay_gain']['track']['peak'])) {
				$this->info['replay_gain']['track']['max_noclip_gain'] = 0 - getid3_lib::RGADamplitude2dB($this->info['replay_gain']['track']['peak']);
			}
			if (isset($this->info['replay_gain']['album']['peak'])) {
				$this->info['replay_gain']['album']['max_noclip_gain'] = 0 - getid3_lib::RGADamplitude2dB($this->info['replay_gain']['album']['peak']);
			}
		}
		return true;
	}

	/**
	 * @return bool
	 */
	public function ProcessAudioStreams() {
		if (!empty($this->info['audio']['bitrate']) || !empty($this->info['audio']['channels']) || !empty($this->info['audio']['sample_rate'])) {
			if (!isset($this->info['audio']['streams'])) {
				foreach ($this->info['audio'] as $key => $value) {
					if ($key != 'streams') {
						$this->info['audio']['streams'][0][$key] = $value;
					}
				}
			}
		}
		return true;
	}

	/**
	 * @return string|bool
	 */
	public function getid3_tempnam() {
		return tempnam($this->tempdir, 'gI3');
	}

	/**
	 * @param string $name
	 *
	 * @return bool
	 *
	 * @throws getid3_exception
	 */
	public function include_module($name) {
		//if (!file_exists($this->include_path.'module.'.$name.'.php')) {
		if (!file_exists(GETID3_INCLUDEPATH.'module.'.$name.'.php')) {
			throw new getid3_exception('Required module.'.$name.'.php is missing.');
		}
		include_once(GETID3_INCLUDEPATH.'module.'.$name.'.php');
		return true;
	}

	/**
	 * @param string $filename
	 *
	 * @return bool
	 */
	public static function is_writable ($filename) {
		$ret = is_writable($filename);
		if (!$ret) {
			$perms = fileperms($filename);
			$ret = ($perms & 0x0080) || ($perms & 0x0010) || ($perms & 0x0002);
		}
		return $ret;
	}

}


abstract class getid3_handler
{

	/**
	* @var getID3
	*/
	protected $getid3;                       // pointer

	/**
	 * Analyzing filepointer or string.
	 *
	 * @var bool
	 */
	protected $data_string_flag     = false;

	/**
	 * String to analyze.
	 *
	 * @var string
	 */
	protected $data_string          = '';

	/**
	 * Seek position in string.
	 *
	 * @var int
	 */
	protected $data_string_position = 0;

	/**
	 * String length.
	 *
	 * @var int
	 */
	protected $data_string_length   = 0;

	/**
	 * @var string
	 */
	private $dependency_to;

	/**
	 * getid3_handler constructor.
	 *
	 * @param getID3 $getid3
	 * @param string $call_module
	 */
	public function __construct(getID3 $getid3, $call_module=null) {
		$this->getid3 = $getid3;

		if ($call_module) {
			$this->dependency_to = str_replace('getid3_', '', $call_module);
		}
	}

	/**
	 * Analyze from file pointer.
	 *
	 * @return bool
	 */
	abstract public function Analyze();

	/**
	 * Analyze from string instead.
	 *
	 * @param string $string
	 */
	public function AnalyzeString($string) {
		// Enter string mode
		$this->setStringMode($string);

		// Save info
		$saved_avdataoffset = $this->getid3->info['avdataoffset'];
		$saved_avdataend    = $this->getid3->info['avdataend'];
		$saved_filesize     = (isset($this->getid3->info['filesize']) ? $this->getid3->info['filesize'] : null); // may be not set if called as dependency without openfile() call

		// Reset some info
		$this->getid3->info['avdataoffset'] = 0;
		$this->getid3->info['avdataend']    = $this->getid3->info['filesize'] = $this->data_string_length;

		// Analyze
		$this->Analyze();

		// Restore some info
		$this->getid3->info['avdataoffset'] = $saved_avdataoffset;
		$this->getid3->info['avdataend']    = $saved_avdataend;
		$this->getid3->info['filesize']     = $saved_filesize;

		// Exit string mode
		$this->data_string_flag = false;
	}

	/**
	 * @param string $string
	 */
	public function setStringMode($string) {
		$this->data_string_flag   = true;
		$this->data_string        = $string;
		$this->data_string_length = strlen($string);
	}

	/**
	 * @return int|bool
	 */
	protected function ftell() {
		if ($this->data_string_flag) {
			return $this->data_string_position;
		}
		return ftell($this->getid3->fp);
	}

	/**
	 * @param int $bytes
	 *
	 * @return string|false
	 *
	 * @throws getid3_exception
	 */
	protected function fread($bytes) {
		if ($this->data_string_flag) {
			$this->data_string_position += $bytes;
			return substr($this->data_string, $this->data_string_position - $bytes, $bytes);
		}
		$pos = $this->ftell() + $bytes;
		if (!getid3_lib::intValueSupported($pos)) {
			throw new getid3_exception('cannot fread('.$bytes.' from '.$this->ftell().') because beyond PHP filesystem limit', 10);
		}

		//return fread($this->getid3->fp, $bytes);
		/*
		* https://www.getid3.org/phpBB3/viewtopic.php?t=1930
		* "I found out that the root cause for the problem was how getID3 uses the PHP system function fread().
		* It seems to assume that fread() would always return as many bytes as were requested.
		* However, according the PHP manual (http://php.net/manual/en/function.fread.php), this is the case only with regular local files, but not e.g. with Linux pipes.
		* The call may return only part of the requested data and a new call is needed to get more."
		*/
		$contents = '';
		do {
			//if (($this->getid3->memory_limit > 0) && ($bytes > $this->getid3->memory_limit)) {
			if (($this->getid3->memory_limit > 0) && (($bytes / $this->getid3->memory_limit) > 0.99)) { // enable a more-fuzzy match to prevent close misses generating errors like "PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 33554464 bytes)"
				throw new getid3_exception('cannot fread('.$bytes.' from '.$this->ftell().') that is more than available PHP memory ('.$this->getid3->memory_limit.')', 10);
			}
			$part = fread($this->getid3->fp, $bytes);
			$partLength  = strlen($part);
			$bytes      -= $partLength;
			$contents   .= $part;
		} while (($bytes > 0) && ($partLength > 0));
		return $contents;
	}

	/**
	 * @param int $bytes
	 * @param int $whence
	 *
	 * @return int
	 *
	 * @throws getid3_exception
	 */
	protected function fseek($bytes, $whence=SEEK_SET) {
		if ($this->data_string_flag) {
			switch ($whence) {
				case SEEK_SET:
					$this->data_string_position = $bytes;
					break;

				case SEEK_CUR:
					$this->data_string_position += $bytes;
					break;

				case SEEK_END:
					$this->data_string_position = $this->data_string_length + $bytes;
					break;
			}
			return 0;
		} else {
			$pos = $bytes;
			if ($whence == SEEK_CUR) {
				$pos = $this->ftell() + $bytes;
			} elseif ($whence == SEEK_END) {
				$pos = $this->getid3->info['filesize'] + $bytes;
			}
			if (!getid3_lib::intValueSupported($pos)) {
				throw new getid3_exception('cannot fseek('.$pos.') because beyond PHP filesystem limit', 10);
			}
		}
		return fseek($this->getid3->fp, $bytes, $whence);
	}

	/**
	 * @return string|false
	 *
	 * @throws getid3_exception
	 */
	protected function fgets() {
		// must be able to handle CR/LF/CRLF but not read more than one lineend
		$buffer   = ''; // final string we will return
		$prevchar = ''; // save previously-read character for end-of-line checking
		if ($this->data_string_flag) {
			while (true) {
				$thischar = substr($this->data_string, $this->data_string_position++, 1);
				if (($prevchar == "\r") && ($thischar != "\n")) {
					// read one byte too many, back up
					$this->data_string_position--;
					break;
				}
				$buffer .= $thischar;
				if ($thischar == "\n") {
					break;
				}
				if ($this->data_string_position >= $this->data_string_length) {
					// EOF
					break;
				}
				$prevchar = $thischar;
			}

		} else {

			// Ideally we would just use PHP's fgets() function, however...
			// it does not behave consistently with regards to mixed line endings, may be system-dependent
			// and breaks entirely when given a file with mixed \r vs \n vs \r\n line endings (e.g. some PDFs)
			//return fgets($this->getid3->fp);
			while (true) {
				$thischar = fgetc($this->getid3->fp);
				if (($prevchar == "\r") && ($thischar != "\n")) {
					// read one byte too many, back up
					fseek($this->getid3->fp, -1, SEEK_CUR);
					break;
				}
				$buffer .= $thischar;
				if ($thischar == "\n") {
					break;
				}
				if (feof($this->getid3->fp)) {
					break;
				}
				$prevchar = $thischar;
			}

		}
		return $buffer;
	}

	/**
	 * @return bool
	 */
	protected function feof() {
		if ($this->data_string_flag) {
			return $this->data_string_position >= $this->data_string_length;
		}