#------------------------------------------------------------------------------ # File: Ogg.pm # # Description: Read Ogg meta information # # Revisions: 2011/07/13 - P. Harvey Created (split from Vorbis.pm) # 2016/07/14 - PH Added Ogg Opus support # # References: 1) http://www.xiph.org/vorbis/doc/ # 2) http://flac.sourceforge.net/ogg_mapping.html # 3) http://www.theora.org/doc/Theora.pdf #------------------------------------------------------------------------------ package Image::ExifTool::Ogg; use strict; use vars qw($VERSION); use Image::ExifTool qw(:DataAccess :Utils); $VERSION = '1.02'; my $MAX_PACKETS = 2; # maximum packets to scan from each stream at start of file # Information types recognizedi in Ogg files %Image::ExifTool::Ogg::Main = ( NOTES => q{ ExifTool extracts the following types of information from Ogg files. See L for the Ogg specification. }, # (these are for documentation purposes only, and aren't used by the code below) vorbis => { SubDirectory => { TagTable => 'Image::ExifTool::Vorbis::Main' } }, theora => { SubDirectory => { TagTable => 'Image::ExifTool::Theora::Main' } }, Opus => { SubDirectory => { TagTable => 'Image::ExifTool::Opus::Main' } }, FLAC => { SubDirectory => { TagTable => 'Image::ExifTool::FLAC::Main' } }, ID3 => { SubDirectory => { TagTable => 'Image::ExifTool::ID3::Main' } }, ); #------------------------------------------------------------------------------ # Process Ogg packet # Inputs: 0) ExifTool object ref, 1) data ref # Returns: 1 on success sub ProcessPacket($$) { my ($et, $dataPt) = @_; my $rtnVal = 0; if ($$dataPt =~ /^(.)(vorbis|theora)/s or $$dataPt =~ /^(OpusHead|OpusTags)/) { my ($tag, $type, $pos) = $2 ? (ord($1), ucfirst($2), 7) : ($1, 'Opus', 8); # this is an OGV file if it contains Theora video $et->OverrideFileType('OGV') if $type eq 'Theora' and $$et{FILE_TYPE} eq 'OGG'; $et->OverrideFileType('OPUS') if $type eq 'Opus' and $$et{FILE_TYPE} eq 'OGG'; my $tagTablePtr = GetTagTable("Image::ExifTool::${type}::Main"); my $tagInfo = $et->GetTagInfo($tagTablePtr, $tag); return 0 unless $tagInfo and $$tagInfo{SubDirectory}; my $subdir = $$tagInfo{SubDirectory}; my %dirInfo = ( DataPt => $dataPt, DirName => $$tagInfo{Name}, DirStart => $pos, ); my $table = GetTagTable($$subdir{TagTable}); # set group1 so Theoris comments can be distinguised from Vorbis comments $$et{SET_GROUP1} = $type if $type eq 'Theora'; SetByteOrder($$subdir{ByteOrder}) if $$subdir{ByteOrder}; $rtnVal = $et->ProcessDirectory(\%dirInfo, $table); SetByteOrder('II'); delete $$et{SET_GROUP1}; } return $rtnVal; } #------------------------------------------------------------------------------ # Extract information from an Ogg file # Inputs: 0) ExifTool object reference, 1) dirInfo reference # Returns: 1 on success, 0 if this wasn't a valid Ogg file sub ProcessOGG($$) { my ($et, $dirInfo) = @_; # must first check for leading/trailing ID3 information unless ($$et{DoneID3}) { require Image::ExifTool::ID3; Image::ExifTool::ID3::ProcessID3($et, $dirInfo) and return 1; } my $raf = $$dirInfo{RAF}; my $verbose = $et->Options('Verbose'); my $out = $et->Options('TextOut'); my ($success, $page, $packets, $streams, $stream) = (0,0,0,0,''); my ($buff, $flag, %val, $numFlac, %streamPage); for (;;) { # must read ahead to next page to see if it is a continuation # (this code would be a lot simpler if the continuation flag # was on the leading instead of the trailing page!) if ($raf and $raf->Read($buff, 28) == 28) { # validate magic number unless ($buff =~ /^OggS/) { $success and $et->Warn('Lost synchronization'); last; } unless ($success) { # set file type and initialize on first page $success = 1; $et->SetFileType(); SetByteOrder('II'); } $flag = Get8u(\$buff, 5); # page flag $stream = Get32u(\$buff, 14); # stream serial number if ($flag & 0x02) { ++$streams; # count start-of-stream pages $streamPage{$stream} = $page = 0; } else { $page = $streamPage{$stream}; } ++$packets unless $flag & 0x01; # keep track of packet count } else { # all done unless we have to process our last packet last unless %val; ($stream) = sort keys %val; # take a stream $flag = 0; # no continuation undef $raf; # flag for done reading } if (defined $numFlac) { # stop to process FLAC headers if we hit the end of file last unless $raf; --$numFlac; # one less header packet to read } else { # can finally process previous packet from this stream # unless this is a continuation page if (defined $val{$stream} and not $flag & 0x01) { ProcessPacket($et, \$val{$stream}); delete $val{$stream}; # only read the first $MAX_PACKETS packets from each stream if ($packets > $MAX_PACKETS * $streams or not defined $raf) { last unless %val; # all done (success!) } } # stop processing Ogg if we have scanned enough packets last if $packets > $MAX_PACKETS * $streams and not %val; } # continue processing the current page my $pageNum = Get32u(\$buff, 18); # page sequence number my $nseg = Get8u(\$buff, 26); # number of segments # calculate total data length my $dataLen = Get8u(\$buff, 27); if ($nseg) { $raf->Read($buff, $nseg-1) == $nseg-1 or last; my @segs = unpack('C*', $buff); # could check that all these (but the last) are 255... foreach (@segs) { $dataLen += $_ } } if (defined $page) { if ($page == $pageNum) { $streamPage{$stream} = ++$page; } else { $et->Warn('Missing page(s) in Ogg file'); undef $page; delete $streamPage{$stream}; } } # read page data $raf->Read($buff, $dataLen) == $dataLen or last; if ($verbose > 1) { printf $out "Page %d, stream 0x%x, flag 0x%x (%d bytes)\n", $pageNum, $stream, $flag, $dataLen; $et->VerboseDump(\$buff, DataPos => $raf->Tell() - $dataLen); } if (defined $val{$stream}) { $val{$stream} .= $buff; # add this continuation page } elsif (not $flag & 0x01) { # ignore remaining pages of a continued packet # ignore the first page of any packet we aren't parsing if ($buff =~ /^(.(vorbis|theora)|Opus(Head|Tags))/s) { $val{$stream} = $buff; # save this page } elsif ($buff =~ /^\x7fFLAC..(..)/s) { $numFlac = unpack('n',$1); $val{$stream} = substr($buff, 9); } } if (defined $numFlac) { # stop to process FLAC headers if we have them all last if $numFlac <= 0; } elsif (defined $val{$stream} and $flag & 0x04) { # process Ogg packet now if end-of-stream bit is set ProcessPacket($et, \$val{$stream}); delete $val{$stream}; } } if (defined $numFlac and defined $val{$stream}) { # process FLAC headers as if it was a complete FLAC file require Image::ExifTool::FLAC; my %dirInfo = ( RAF => new File::RandomAccess(\$val{$stream}) ); Image::ExifTool::FLAC::ProcessFLAC($et, \%dirInfo); } return $success; } 1; # end __END__ =head1 NAME Image::ExifTool::Ogg - Read Ogg meta information =head1 SYNOPSIS This module is used by Image::ExifTool =head1 DESCRIPTION This module contains definitions required by Image::ExifTool to extract meta information from Ogg bitstream container files. =head1 AUTHOR Copyright 2003-2018, Phil Harvey (phil at owl.phy.queensu.ca) This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. =head1 REFERENCES =over 4 =item L =item L =item L =back =head1 SEE ALSO L, L =cut