getid3_ogg::ParseVorbisComments(): bool

587	public function ParseVorbisComments() {588		$info = &$this->getid3->info;589 590		$OriginalOffset = $this->ftell();591		$commentdata = null;592		$commentdataoffset = 0;593		$VorbisCommentPage = 1;594		$CommentStartOffset = 0;595 596		switch ($info['audio']['dataformat']) {597			case 'vorbis':598			case 'speex':599			case 'opus':600				$CommentStartOffset = $info['ogg']['pageheader'][$VorbisCommentPage]['page_start_offset'];  // Second Ogg page, after header block601				$this->fseek($CommentStartOffset);602				$commentdataoffset = 27 + $info['ogg']['pageheader'][$VorbisCommentPage]['page_segments'];603				$commentdata = $this->fread(self::OggPageSegmentLength($info['ogg']['pageheader'][$VorbisCommentPage], 1) + $commentdataoffset);604 605				if ($info['audio']['dataformat'] == 'vorbis') {606					$commentdataoffset += (strlen('vorbis') + 1);607				}608				else if ($info['audio']['dataformat'] == 'opus') {609					$commentdataoffset += strlen('OpusTags');610				}611 612				break;613 614			case 'flac':615				$CommentStartOffset = $info['flac']['VORBIS_COMMENT']['raw']['offset'] + 4;616				$this->fseek($CommentStartOffset);617				$commentdata = $this->fread($info['flac']['VORBIS_COMMENT']['raw']['block_length']);618				break;619 620			default:621				return false;622		}623 624		$VendorSize = getid3_lib::LittleEndian2Int(substr($commentdata, $commentdataoffset, 4));625		$commentdataoffset += 4;626 627		$info['ogg']['vendor'] = substr($commentdata, $commentdataoffset, $VendorSize);628		$commentdataoffset += $VendorSize;629 630		$CommentsCount = getid3_lib::LittleEndian2Int(substr($commentdata, $commentdataoffset, 4));631		$commentdataoffset += 4;632		$info['avdataoffset'] = $CommentStartOffset + $commentdataoffset;633 634		$basicfields = array('TITLE', 'ARTIST', 'ALBUM', 'TRACKNUMBER', 'GENRE', 'DATE', 'DESCRIPTION', 'COMMENT');635		$ThisFileInfo_ogg_comments_raw = &$info['ogg']['comments_raw'];636		for ($i = 0; $i < $CommentsCount; $i++) {637 638			if ($i >= 10000) {639				// https://github.com/owncloud/music/issues/212#issuecomment-43082336640				$this->warning('Unexpectedly large number ('.$CommentsCount.') of Ogg comments - breaking after reading '.$i.' comments');641				break;642			}643 644			$ThisFileInfo_ogg_comments_raw[$i]['dataoffset'] = $CommentStartOffset + $commentdataoffset;645 646			if ($this->ftell() < ($ThisFileInfo_ogg_comments_raw[$i]['dataoffset'] + 4)) {647				if ($oggpageinfo = $this->ParseOggPageHeader()) {648					$info['ogg']['pageheader'][$oggpageinfo['page_seqno']] = $oggpageinfo;649 650					$VorbisCommentPage++;651 652					// First, save what we haven't read yet653					$AsYetUnusedData = substr($commentdata, $commentdataoffset);654 655					// Then take that data off the end656					$commentdata     = substr($commentdata, 0, $commentdataoffset);657 658					// Add [headerlength] bytes of dummy data for the Ogg Page Header, just to keep absolute offsets correct659					$commentdata .= str_repeat("\x00", 27 + $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_segments']);660					$commentdataoffset += (27 + $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_segments']);661 662					// Finally, stick the unused data back on the end663					$commentdata .= $AsYetUnusedData;664 665					//$commentdata .= $this->fread($info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_length']);666					$commentdata .= $this->fread($this->OggPageSegmentLength($info['ogg']['pageheader'][$VorbisCommentPage], 1));