3rdparty/getID3/demos/demo.mp3header.php ➔ md5_data()

Complexity

Conditions	12
Paths	13

Size

Total Lines

73

Duplication

Lines	8
Ratio	10.96 %

Importance

Changes

0

<?php
	function md5_data($file, $offset, $end, $invertsign=false) {
		// first try and create a temporary file in the same directory as the file being scanned
		if (($dataMD5filename = tempnam(dirname($file), preg_replace('#[^[:alnum:]]#i', '', basename($file)))) === false) {
			// if that fails, create a temporary file in the system temp directory
			if (($dataMD5filename = tempnam('/tmp', 'getID3')) === false) {
				// if that fails, create a temporary file in the current directory
				if (($dataMD5filename = tempnam('.', preg_replace('#[^[:alnum:]]#i', '', basename($file)))) === false) {
					// can't find anywhere to create a temp file, just die
					return false;
				}
			}
		}
		$md5 = false;
		set_time_limit(max(filesize($file) / 1000000, 30));

		// copy parts of file
		ob_start();
		if ($fp = fopen($file, 'rb')) {
			ob_end_clean();

			ob_start();
			if ($MD5fp = fopen($dataMD5filename, 'wb')) {

				ob_end_clean();
				if ($invertsign) {
					// Load conversion lookup strings for 8-bit unsigned->signed conversion below
					$from = '';
					$to   = '';
					for ($i = 0; $i < 128; $i++) {

This code seems to be duplicated across your project.

						$from .= chr($i);
						$to   .= chr($i + 128);
					}
					for ($i = 128; $i < 256; $i++) {

This code seems to be duplicated across your project.

						$from .= chr($i);
						$to   .= chr($i - 128);
					}
				}

				fseek($fp, $offset, SEEK_SET);
				$byteslefttowrite = $end - $offset;
				while (($byteslefttowrite > 0) && ($buffer = fread($fp, 32768))) {
					if ($invertsign) {
						// Possibly FLAC-specific (?)
						// FLAC calculates the MD5sum of the source data of 8-bit files
						// not on the actual byte values in the source file, but of those
						// values converted from unsigned to signed, or more specifcally,
						// with the MSB inverted. ex: 01 -> 81; F5 -> 75; etc

						// Therefore, 8-bit WAV data has to be converted before getting the
						// md5_data value so as to match the FLAC value

						// Flip the MSB for each byte in the buffer before copying
						$buffer = strtr($buffer, $from, $to);

The variable $from does not seem to be defined for all execution paths leading up to this point.

The variable $to does not seem to be defined for all execution paths leading up to this point.

					}
					$byteswritten = fwrite($MD5fp, $buffer, $byteslefttowrite);
					$byteslefttowrite -= $byteswritten;
				}
				fclose($MD5fp);
				$md5 = md5_file($dataMD5filename);

			} else {
				$errormessage = ob_get_contents();

$errormessage is not used, you could remove the assignment.

				ob_end_clean();
			}
			fclose($fp);

		} else {
			$errormessage = ob_get_contents();

$errormessage is not used, you could remove the assignment.

			ob_end_clean();
		}
		unlink($dataMD5filename);
		return $md5;
	}
}