getid3_id3v1

21class getid3_id3v1 extends getid3_handler22{23	/**24	 * @return bool25	 */26	public function Analyze() {27		$info = &$this->getid3->info;28 29		if (!getid3_lib::intValueSupported($info['filesize'])) {30			$this->warning('Unable to check for ID3v1 because file is larger than '.round(PHP_INT_MAX / 1073741824).'GB');31			return false;32		} elseif ($info['filesize'] < 128) {33			$this->warning('Unable to check for ID3v1 because file is too small');34			return false;35		}36 37		if($info['filesize'] < 256) {38			$this->fseek(-128, SEEK_END);39			$preid3v1 = '';40			$id3v1tag = $this->fread(128);41		} else {42			$this->fseek(-256, SEEK_END);43			$preid3v1 = $this->fread(128);44			$id3v1tag = $this->fread(128);45		}46 47 48		if (substr($id3v1tag, 0, 3) == 'TAG') {49 50			$info['avdataend'] = $info['filesize'] - 128;51 52			$ParsedID3v1            = array();53			$ParsedID3v1['title']   = $this->cutfield(substr($id3v1tag,   3, 30));54			$ParsedID3v1['artist']  = $this->cutfield(substr($id3v1tag,  33, 30));55			$ParsedID3v1['album']   = $this->cutfield(substr($id3v1tag,  63, 30));56			$ParsedID3v1['year']    = $this->cutfield(substr($id3v1tag,  93,  4));57			$ParsedID3v1['comment'] =                 substr($id3v1tag,  97, 30);  // can't remove nulls yet, track detection depends on them58			$ParsedID3v1['genreid'] =             ord(substr($id3v1tag, 127,  1));59 60			// If second-last byte of comment field is null and last byte of comment field is non-null61			// then this is ID3v1.1 and the comment field is 28 bytes long and the 30th byte is the track number62			if (($id3v1tag[125] === "\x00") && ($id3v1tag[126] !== "\x00")) {63				$ParsedID3v1['track_number'] = ord(substr($ParsedID3v1['comment'], 29,  1));64				$ParsedID3v1['comment']      =     substr($ParsedID3v1['comment'],  0, 28);65			}66			$ParsedID3v1['comment'] = $this->cutfield($ParsedID3v1['comment']);67 68			$ParsedID3v1['genre'] = $this->LookupGenreName($ParsedID3v1['genreid']);69			if (!empty($ParsedID3v1['genre'])) {70				unset($ParsedID3v1['genreid']);71			}72			if (empty($ParsedID3v1['genre']) || ($ParsedID3v1['genre'] == 'Unknown')) {73				unset($ParsedID3v1['genre']);74			}75 76			foreach ($ParsedID3v1 as $key => $value) {77				$ParsedID3v1['comments'][$key][0] = $value;78			}79			$ID3v1encoding = $this->getid3->encoding_id3v1;80			if ($this->getid3->encoding_id3v1_autodetect) {81				// ID3v1 encoding detection hack START82				// ID3v1 is defined as always using ISO-8859-1 encoding, but it is not uncommon to find files tagged with ID3v1 using Windows-1251 or other character sets83				// Since ID3v1 has no concept of character sets there is no certain way to know we have the correct non-ISO-8859-1 character set, but we can guess84				foreach ($ParsedID3v1['comments'] as $tag_key => $valuearray) {85					foreach ($valuearray as $key => $value) {86						if (preg_match('#^[\\x00-\\x40\\x80-\\xFF]+$#', $value) && !ctype_digit((string) $value)) { // check for strings with only characters above chr(128) and punctuation/numbers, but not just numeric strings (e.g. track numbers or years)87							foreach (array('Windows-1251', 'KOI8-R') as $id3v1_bad_encoding) {88								if (function_exists('mb_convert_encoding') && @mb_convert_encoding($value, $id3v1_bad_encoding, $id3v1_bad_encoding) === $value) {89									$ID3v1encoding = $id3v1_bad_encoding;90									$this->warning('ID3v1 detected as '.$id3v1_bad_encoding.' text encoding in '.$tag_key);91									break 3;92								} elseif (function_exists('iconv') && @iconv($id3v1_bad_encoding, $id3v1_bad_encoding, $value) === $value) {93									$ID3v1encoding = $id3v1_bad_encoding;94									$this->warning('ID3v1 detected as '.$id3v1_bad_encoding.' text encoding in '.$tag_key);95									break 3;96								}97							}98						}99					}100				}