#------------------------------------------------------------------------------
# File:         Matroska.pm
#
# Description:  Read meta information from Matroska multimedia files
#
# Revisions:    05/26/2010 - P. Harvey Created
#
# References:   1) http://www.matroska.org/technical/specs/index.html
#------------------------------------------------------------------------------

package Image::ExifTool::Matroska;

use strict;
use vars qw($VERSION);
use Image::ExifTool qw(:DataAccess :Utils);

$VERSION = '1.01';

my %noYes = ( 0 => 'No', 1 => 'Yes' );

%Image::ExifTool::Matroska::Main = (
    GROUPS => { 2 => 'Video' },
    NOTES => q{
        Tags extracted from Matroska multimedia container (MKA, MKV and MKS) files.
        For speed, ExifTool extracts tags only up to the first Cluster unless the
        Verbose (-v) or Unknown = 2 (-U) option is used.  See
        L<http://www.matroska.org/technical/specs/index.html> for the official
        Matroska specification.
    },
    # supported Format's: signed, unsigned, float, date, string, utf8
    # (or undef by default)
#
# EBML Header
#
    0xa45dfa3 => {
        Name => 'EBMLHeader',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x286 => { Name => 'EBMLVersion',       Format => 'unsigned' },
    0x2f7 => { Name => 'EBMLReadVersion',   Format => 'unsigned' },
    0x2f2 => { Name => 'EBMLMaxIDLength',   Format => 'unsigned', Unknown => 1 },
    0x2f3 => { Name => 'EBMLMaxSizeLength', Format => 'unsigned', Unknown => 1 },
    0x282 => { Name => 'DocType',           Format => 'string' },
    0x287 => { Name => 'DocTypeVersion',    Format => 'unsigned' },
    0x285 => { Name => 'DocTypeReadVersion',Format => 'unsigned' },
#
# General
#
    0x3f  => { Name => 'CRC-32',            Binary => 1, Unknown => 1 },
    0x6c  => { Name => 'Void',              NoSave => 1, Unknown => 1 },
#
# Signature
#
    0xb538667 => {
        Name => 'SignatureSlot',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x3e8a => { Name => 'SignatureAlgo',    Format => 'unsigned' },
    0x3e9a => { Name => 'SignatureHash',    Format => 'unsigned' },
    0x3ea5 => { Name =>'SignaturePublicKey',Binary => 1, Unknown => 1 },
    0x3eb5 => { Name => 'Signature',        Binary => 1, Unknown => 1 },
    0x3e5b => {
        Name => 'SignatureElements',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x3e7b => {
        Name => 'SignatureElementList',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x2532 => { Name => 'SignedElement',    Binary => 1, Unknown => 1 },
#
# Segment
#
    0x8538067 => {
        Name => 'SegmentHeader',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x14d9b74 => {
        Name => 'SeekHead',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0xdbb => {
        Name => 'Seek',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x13ab => { Name => 'SeekID',           Binary => 1, Unknown => 1 },
    0x13ac => { Name => 'SeekPosition',     Format => 'unsigned', Unknown => 1 },
#
# Segment Info
#
    0x549a966 => {
        Name => 'Info',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x33a4 => { Name => 'SegmentUID',       Binary => 1, Unknown => 1 },
    0x3384 => { Name => 'SegmentFileName',  Format => 'utf8' },
    0x1cb923 => { Name => 'PrevUID',        Binary => 1, Unknown => 1 },
    0x1c83ab => { Name => 'PrevFileName',   Format => 'utf8' },
    0x1eb923 => { Name => 'NextUID',        Binary => 1, Unknown => 1 },
    0x1e83bb => { Name => 'NextFileName',   Format => 'utf8' },
    0x0444 => { Name => 'SegmentFamily',    Binary => 1, Unknown => 1 },
    0x2924 => {
        Name => 'ChapterTranslate',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x29fc => { Name => 'ChapterTranslateEditionUID',Format => 'unsigned', Unknown => 1 },
    0x29bf => {
        Name => 'ChapterTranslateCodec',
        Format => 'unsigned',
        PrintConv => { 0 => 'Matroska Script', 1 => 'DVD Menu' },
    },
    0x29a5 => { Name => 'ChapterTranslateID',Binary => 1, Unknown => 1 },
    0xad7b1 => {
        Name => 'TimecodeScale',
        Format => 'unsigned',
        RawConv => '$$self{TimecodeScale} = $val',
        ValueConv => '$val / 1e9',
        PrintConv => '($val * 1000) . " ms"',
    },
    0x489 => {
        Name => 'Duration',
        Format => 'float',
        ValueConv => '$$self{TimecodeScale} ? $val * $$self{TimecodeScale} / 1e9 : $val',
        PrintConv => '$$self{TimecodeScale} ? ConvertDuration($val) : $val',
    },
    0x461 => {
        Name => 'DateTimeOriginal', # called "DateUTC" by the spec
        Description => 'Date/Time Original',
        Groups => { 2 => 'Time' },
        Format => 'date',
        PrintConv => '$self->ConvertDateTime($val)',
    },
    0x3ba9 => { Name => 'Title',            Format => 'utf8' },
    0xd80  => { Name => 'MuxingApp',        Format => 'utf8' },
    0x1741 => { Name => 'WritingApp',       Format => 'utf8' },
#
# Cluster
#
    0xf43b675 => {
        Name => 'Cluster',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x67 => {
        Name => 'Timecode',
        Format => 'unsigned',
        Unknown => 1,
        ValueConv => '$$self{TimecodeScale} ? $val * $$self{TimecodeScale} / 1e9 : $val',
        PrintConv => '$$self{TimecodeScale} ? ConvertDuration($val) : $val',
    },
    0x1854 => {
        Name => 'SilentTracks',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x18d7 => { Name => 'SilentTrackNumber',Format => 'unsigned' },
    0x27   => { Name => 'Position',         Format => 'unsigned' },
    0x2b   => { Name => 'PrevSize',         Format => 'unsigned' },
    0x23   => { Name => 'SimpleBlock',      NoSave => 1, Unknown => 1 },
    0x20 => {
        Name => 'BlockGroup',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x21   => { Name => 'Block',            NoSave => 1, Unknown => 1 },
    0x22   => { Name => 'BlockVirtual',     NoSave => 1, Unknown => 1 },
    0x35a1 => {
        Name => 'BlockAdditions',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x26 => {
        Name => 'BlockMore',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x6e   => { Name => 'BlockAddID',       Format => 'unsigned', Unknown => 1 },
    0x25   => { Name => 'BlockAdditional',  NoSave => 1, Unknown => 1 },
    0x1b   => {
        Name => 'BlockDuration',
        Format => 'unsigned',
        Unknown => 1,
        ValueConv => '$$self{TimecodeScale} ? $val * $$self{TimecodeScale} / 1e9 : $val',
        PrintConv => '$$self{TimecodeScale} ? "$val s" : $val',
    },
    0x7a   => { Name => 'ReferencePriority',Format => 'unsigned', Unknown => 1 },
    0x7b   => {
        Name => 'ReferenceBlock',
        Format => 'signed',
        Unknown => 1,
        ValueConv => '$$self{TimecodeScale} ? $val * $$self{TimecodeScale} / 1e9 : $val',
        PrintConv => '$$self{TimecodeScale} ? "$val s" : $val',
    },
    0x7d   => { Name => 'ReferenceVirtual', Format => 'signed', Unknown => 1 },
    0x24   => { Name => 'CodecState',       Binary => 1, Unknown => 1 },
    0x0e => {
        Name => 'Slices',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x68 => {
        Name => 'TimeSlice',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x4c   => { Name => 'LaceNumber',       Format => 'unsigned', Unknown => 1 },
    0x4d   => { Name => 'FrameNumber',      Format => 'unsigned', Unknown => 1 },
    0x4b   => { Name => 'BlockAdditionalID',Format => 'unsigned', Unknown => 1 },
    0x4e   => { Name => 'Delay',            Format => 'unsigned', Unknown => 1 },
    0x4f   => { Name => 'ClusterDuration',  Format => 'unsigned', Unknown => 1 },
    0x2f   => { Name => 'EncryptedBlock',   NoSave => 1, Unknown => 1 },
#
# Tracks
#
    0x654ae6b => {
        Name => 'Tracks',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x2e => {
        Name => 'TrackEntry',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x57   => { Name => 'TrackNumber',      Format => 'unsigned' },
    0x33c5 => { Name => 'TrackUID',         Format => 'unsigned', Unknown => 1 },
    0x03 => {
        Name => 'TrackType',
        Format => 'unsigned',
        PrintHex => 1,
        # remember types of all tracks encountered, as well as the current track type
        RawConv => '$$self{TrackTypes}{$val} = 1; $$self{TrackType} = $val',
        PrintConv => {
            0x01 => 'Video',
            0x02 => 'Audio',
            0x03 => 'Complex', # (audio+video)
            0x10 => 'Logo',
            0x11 => 'Subtitle',
            0x12 => 'Buttons',
            0x20 => 'Control',
        },
    },
    0x39   => { Name => 'TrackUsed',        Format => 'unsigned', PrintConv => \%noYes },
    0x08   => { Name => 'TrackDefault',     Format => 'unsigned', PrintConv => \%noYes },
    0x15aa => { Name => 'TrackForced',      Format => 'unsigned', PrintConv => \%noYes },
    0x1c => {
        Name => 'TrackLacing',
        Format => 'unsigned',
        Unknown => 1,
        PrintConv => \%noYes,
    },
    0x2de7 => { Name => 'MinCache',         Format => 'unsigned', Unknown => 1 },
    0x2df8 => { Name => 'MaxCache',         Format => 'unsigned', Unknown => 1 },
    0x3e383 => [
        {
            Name => 'VideoFrameRate',
            Condition => '$$self{TrackType} and $$self{TrackType} == 0x01',
            Format => 'unsigned',
            ValueConv => '$val ? 1e9 / $val : 0',
            PrintConv => 'int($val * 1000 + 0.5) / 1000',
        },{
            Name => 'DefaultDuration',
            Format => 'unsigned',
            ValueConv => '$val / 1e9',
            PrintConv => '($val * 1000) . " ms"',
        }
    ],
    0x3314f => { Name => 'TrackTimecodeScale',Format => 'float' },
    0x137f  => { Name => 'TrackOffset',     Format => 'signed', Unknown => 1 },
    0x15ee  => { Name => 'MaxBlockAdditionID',Format => 'unsigned', Unknown => 1 },
    0x136e  => { Name => 'TrackName',       Format => 'utf8' },
    0x2b59c => { Name => 'TrackLanguage',   Format => 'string' },
    0x06 => [
        {
            Name => 'VideoCodecID',
            Condition => '$$self{TrackType} and $$self{TrackType} == 0x01',
            Format => 'string',
        },{
            Name => 'AudioCodecID',
            Condition => '$$self{TrackType} and $$self{TrackType} == 0x02',
            Format => 'string',
        },{
            Name => 'CodecID',
            Format => 'string',
        }
    ],
    0x23a2 => { Name => 'CodecPrivate',     Binary => 1, Unknown => 1 },
    0x58688 => [
        {
            Name => 'VideoCodecName',
            Condition => '$$self{TrackType} and $$self{TrackType} == 0x01',
            Format => 'utf8',
        },{
            Name => 'AudioCodecName',
            Condition => '$$self{TrackType} and $$self{TrackType} == 0x02',
            Format => 'utf8',
        },{
            Name => 'CodecName',
            Format => 'utf8',
        }
    ],
    0x3446 => { Name => 'TrackAttachmentUID',Format => 'unsigned' },
    0x1a9697=>{ Name => 'CodecSettings',    Format => 'utf8' },
    0x1b4040=>{ Name => 'CodecInfoURL',     Format => 'string' },
    0x6b240 =>{ Name => 'CodecDownloadURL', Format => 'string' },
    0x2a   => { Name => 'CodecDecodeAll',   Format => 'unsigned', PrintConv => \%noYes },
    0x2fab => { Name => 'TrackOverlay',     Format => 'unsigned', Unknown => 1 },
    0x2624 => {
        Name => 'TrackTranslate',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x26fc => { Name => 'TrackTranslateEditionUID',Format => 'unsigned', Unknown => 1 },
    0x26bf => {
        Name => 'TrackTranslateCodec',
        Format => 'unsigned',
        PrintConv => { 0 => 'Matroska Script', 1 => 'DVD Menu' },
    },
    0x26a5 => { Name => 'TrackTranslateTrackID', Binary => 1, Unknown => 1 },
#
# Video
#
    0x60 => {
        Name => 'Video',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x1a => {
        Name => 'VideoScanType',
        Format => 'unsigned',
        PrintConv => {
            0 => 'Progressive',
            1 => 'Interlaced',
        },
    },
    0x13b8 => {
        Name => 'Stereo3DMode',
        Format => 'unsigned',
        Printconv => {
            0 => 'Mono',
            1 => 'Right Eye',
            2 => 'Left Eye',
            3 => 'Both Eyes',
        },
    },
    0x30   => { Name => 'ImageWidth',       Format => 'unsigned' },
    0x3a   => { Name => 'ImageHeight',      Format => 'unsigned' },
    0x14aa => { Name => 'CropBottom',       Format => 'unsigned' },
    0x14bb => { Name => 'CropTop',          Format => 'unsigned' },
    0x14cc => { Name => 'CropLeft',         Format => 'unsigned' },
    0x14dd => { Name => 'CropRight',        Format => 'unsigned' },
    0x14b0 => { Name => 'DisplayWidth',     Format => 'unsigned' },
    0x14ba => { Name => 'DisplayHeight',    Format => 'unsigned' },
    0x14b2 => {
        Name => 'DisplayUnit',
        Format => 'unsigned',
        PrintConv => {
            0 => 'Pixels',
            1 => 'cm',
            2 => 'inches',
        },
    },
    0x14b3 => {
        Name => 'AspectRatioType',
        Format => 'unsigned',
        PrintConv => {
            0 => 'Free Resizing',
            1 => 'Keep Aspect Ratio',
            2 => 'Fixed',
        },
    },
    0xeb524 => { Name => 'ColorSpace',      Binary => 1, Unknown => 1 },
    0xfb523 => { Name => 'Gamma',           Format => 'float' },
    0x383e3 => { Name => 'FrameRate',       Format => 'float' },
#
# Audio
#
    0x61 => {
        Name => 'Audio',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x35   => { Name => 'AudioSampleRate',  Format => 'float',     Groups => { 2 => 'Audio' } },
    0x38b5 => { Name => 'OutputAudioSampleRate',Format => 'float', Groups => { 2 => 'Audio' } },
    0x1f   => { Name => 'AudioChannels',    Format => 'unsigned',  Groups => { 2 => 'Audio' } },
    0x3d7b => {
        Name => 'ChannelPositions',
        Binary => 1,
        Unknown => 1,
        Groups => { 2 => 'Audio' },
    },
    0x2264 => { Name => 'AudioSampleBits',  Format => 'unsigned', Groups => { 2 => 'Audio' } },
#
# Content Encoding
#
    0x2d80 => {
        Name => 'ContentEncodings',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x2240 => {
        Name => 'ContentEncoding',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x1031 => { Name => 'ContentEncodingOrder', Format => 'unsigned', Unknown => 1 },
    0x1032 => { Name => 'ContentEncodingScope', Format => 'unsigned', Unknown => 1 },
    0x1033 => {
        Name => 'ContentEncodingType',
        Format => 'unsigned',
        PrintConv => { 0 => 'Compression', 1 => 'Encryption' },
    },
    0x1034 => {
        Name => 'ContentCompression',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x254 => {
        Name => 'ContentCompressionAlgorithm',
        Format => 'unsigned',
        PrintConv => {
            0 => 'zlib',
            1 => 'bzlib',
            2 => 'lzo1x',
            3 => 'Header Stripping',
        },
    },
    0x255 => { Name => 'ContentCompressionSettings',Binary => 1, Unknown => 1 },
    0x1035 => {
        Name => 'ContentEncryption',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x7e1 => {
        Name => 'ContentEncryptionAlgorithm',
        Format => 'unsigned',
        PrintConv => {
            0 => 'Not Encrypted',
            1 => 'DES',
            2 => '3DES',
            3 => 'Twofish',
            4 => 'Blowfish',
            5 => 'AES',
        },
    },
    0x7e2 => { Name => 'ContentEncryptionKeyID',Binary => 1, Unknown => 1 },
    0x7e3 => { Name => 'ContentSignature',      Binary => 1, Unknown => 1 },
    0x7e4 => { Name => 'ContentSignatureKeyID', Binary => 1, Unknown => 1 },
    0x7e5 => {
        Name => 'ContentSignatureAlgorithm',
        Format => 'unsigned',
        PrintConv => {
            0 => 'Not Signed',
            1 => 'RSA',
        },
    },
    0x7e6 => {
        Name => 'ContentSignatureHashAlgorithm',
        Format => 'unsigned',
        PrintConv => {
            0 => 'Not Signed',
            1 => 'SHA1-160',
            2 => 'MD5',
        },
    },
#
# Cues
#
    0xc53bb6b => {
        Name => 'Cues',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x3b => {
        Name => 'CuePoint',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x33 => {
        Name => 'CueTime',
        Format => 'unsigned',
        Unknown => 1,
        ValueConv => '$$self{TimecodeScale} ? $val * $$self{TimecodeScale} / 1e9 : $val',
        PrintConv => '$$self{TimecodeScale} ? ConvertDuration($val) : $val',
    },
    0x37 => {
        Name => 'CueTrackPositions',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x77   => { Name => 'CueTrack',         Format => 'unsigned', Unknown => 1 },
    0x71   => { Name => 'CueClusterPosition',Format => 'unsigned', Unknown => 1 },
    0x1378 => { Name => 'CueBlockNumber',   Format => 'unsigned', Unknown => 1 },
    0x6a   => { Name => 'CueCodecState',    Format => 'unsigned', Unknown => 1 },
    0x5b => {
        Name => 'CueReference',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x16 => {
        Name => 'CueRefTime',
        Format => 'unsigned',
        Unknown => 1,
        ValueConv => '$$self{TimecodeScale} ? $val * $$self{TimecodeScale} / 1e9 : $val',
        PrintConv => '$$self{TimecodeScale} ? ConvertDuration($val) : $val',
    },
    0x17  => { Name => 'CueRefCluster',     Format => 'unsigned', Unknown => 1 },
    0x135f=> { Name => 'CueRefNumber',      Format => 'unsigned', Unknown => 1 },
    0x6b  => { Name => 'CueRefCodecState',  Format => 'unsigned', Unknown => 1 },
#
# Attachments
#
    0x941a469 => {
        Name => 'Attachments',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x21a7 => {
        Name => 'AttachedFile',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x67e => { Name => 'AttachedFileDescription',Format => 'utf8' },
    0x66e => { Name => 'AttachedFileName',      Format => 'utf8' },
    0x660 => { Name => 'AttachedFileMIMEType',  Format => 'string' },
    0x65c => { Name => 'AttachedFileData',      Binary => 1 },
    0x6ae => { Name => 'AttachedFileUID',       Format => 'unsigned' },
    0x675 => { Name => 'AttachedFileReferral',  Binary => 1, Unknown => 1 },
#
# Chapters
#
    0x43a770 => {
        Name => 'Chapters',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x5b9 => {
        Name => 'EditionEntry',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x5bc => { Name => 'EditionUID',        Format => 'unsigned', Unknown => 1 },
    0x5bd => { Name => 'EditionFlagHidden', Format => 'unsigned', Unknown => 1 },
    0x5db => { Name => 'EditionFlagDefault',Format => 'unsigned', Unknown => 1 },
    0x5dd => { Name => 'EditionFlagOrdered',Format => 'unsigned', Unknown => 1 },
    0x36 => {
        Name => 'ChapterAtom',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x33c4 => { Name => 'ChapterUID',       Format => 'unsigned', Unknown => 1 },
    0x11 => {
        Name => 'ChapterTimeStart',
        Groups => { 1 => 'Chapter#' },
        Format => 'unsigned',
        ValueConv => '$val / 1e9',
        PrintConv => 'ConvertDuration($val)',
    },
    0x12 => {
        Name => 'ChapterTimeEnd',
        Format => 'unsigned',
        ValueConv => '$val / 1e9',
        PrintConv => 'ConvertDuration($val)',
    },
    0x18  => { Name => 'ChapterFlagHidden', Format => 'unsigned', Unknown => 1 },
    0x598 => { Name => 'ChapterFlagEnabled',Format => 'unsigned', Unknown => 1 },
    0x2e67=> { Name => 'ChapterSegmentUID', Binary => 1, Unknown => 1 },
    0x2ebc=> { Name => 'ChapterSegmentEditionUID', Binary => 1, Unknown => 1 },
    0x23c3 => {
        Name => 'ChapterPhysicalEquivalent',
        Format => 'unsigned',
        PrintConv => {
            10 => 'Index',
            20 => 'Track',
            30 => 'Session',
            40 => 'Layer',
            50 => 'Side',
            60 => 'CD / DVD',
            70 => 'Set / Package',
        },
    },
    0x0f => {
        Name => 'ChapterTrack',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x09 => { Name => 'ChapterTrackNumber', Format => 'unsigned', Unknown => 1 },
    0x00 => {
        Name => 'ChapterDisplay',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x05  => { Name => 'ChapterString',     Format => 'utf8' },
    0x37c => { Name => 'ChapterLanguage',   Format => 'string' },
    0x37e => { Name => 'ChapterCountry',    Format => 'string' },
    0x2944 => {
        Name => 'ChapterProcess',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x2955 => {
        Name => 'ChapterProcessCodecID',
        Format => 'unsigned',
        Unknown => 1,
        PrintConv => { 0 => 'Matroska', 1 => 'DVD' },
    },
    0x50d => { Name => 'ChapterProcessPrivate', Binary => 1, Unknown => 1 },
    0x2911 => {
        Name => 'ChapterProcessCommand',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x2922 => {
        Name => 'ChapterProcessTime',
        Format => 'unsigned',
        Unknown => 1,
        PrintConv => {
            0 => 'For Duration of Chapter',
            1 => 'Before Chapter',
            2 => 'After Chapter',
        },
    },
    0x2933 => { Name => 'ChapterProcessData',   Binary => 1, Unknown => 1 },
#
# Tags
#
    0x254c367 => {
        Name => 'Tags',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x3373 => {
        Name => 'Tag',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x23c0 => {
        Name => 'Targets',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x28ca => { Name => 'TargetTypeValue',  Format => 'unsigned' },
    0x23ca => { Name => 'TargetType',       Format => 'string' },
    0x23c5 => { Name => 'TagTrackUID',      Format => 'unsigned', Unknown => 1 },
    0x23c9 => { Name => 'TagEditionUID',    Format => 'unsigned', Unknown => 1 },
    0x23c4 => { Name => 'TagChapterUID',    Format => 'unsigned', Unknown => 1 },
    0x23c6 => { Name => 'TagAttachmentUID', Format => 'unsigned', Unknown => 1 },
    0x27c8 => {
        Name => 'SimpleTag',
        SubDirectory => { TagTable => 'Image::ExifTool::Matroska::Main' },
    },
    0x5a3 => { Name => 'TagName',           Format => 'utf8' },
    0x47a => { Name => 'TagLanguage',       Format => 'string' },
    0x484 => { Name => 'TagDefault',        Format => 'unsigned', PrintConv => \%noYes },
    0x487 => { Name => 'TagString',         Format => 'utf8' },
    0x485 => { Name => 'TagBinary',         Binary => 1 },
);

#------------------------------------------------------------------------------
# Get variable-length Matroska integer
# Inputs: 0) data buffer, 1) position in data
# Returns: integer value and updates position, -1 for unknown value,
#          or undef if no data left
sub GetVInt($$)
{
    return undef if $_[1] >= length $_[0];
    my $val = ord(substr($_[0], $_[1]++));
    my $num = 0;
    unless ($val) {
        return undef if $_[1] >= length $_[0];
        $val = ord(substr($_[0], $_[1]++));
        return undef unless $val;   # can't be this large!
        $num += 7;  # 7 more bytes to read (we just read one)
    }
    my $mask = 0x7f;
    while ($val == ($val & $mask)) {
        $mask >>= 1;
        ++$num;
    }
    $val = ($val & $mask);
    my $unknown = ($val == $mask);
    return undef if $_[1] + $num > length $_[0];
    while ($num) {
        my $b = ord(substr($_[0], $_[1]++));
        $unknown = 0 if $b != 0xff;
        $val = $val * 256 + $b;
        --$num;
    }
    return $unknown ? -1 : $val;
}

#------------------------------------------------------------------------------
# Read information from a Matroska multimedia file (MKV, MKA, MKS)
# Inputs: 0) ExifTool object reference, 1) Directory information reference
# Returns: 1 on success, 0 if this wasn't a valid Matroska file
sub ProcessMKV($$)
{
    my ($exifTool, $dirInfo) = @_;
    my $raf = $$dirInfo{RAF};
    my ($buff, $buf2, @dirEnd, $trackIndent, %trackTypes);

    $raf->Read($buff, 4) == 4 or return 0;
    return 0 unless $buff =~ /^\x1a\x45\xdf\xa3/;

    # read in 64kB blocks (already read 4 bytes)
    $raf->Read($buff, 65532) or return 0;
    my $dataLen = length $buff;
    my ($pos, $dataPos) = (0, 4);

    # verify header length
    my $hlen = GetVInt($buff, $pos);
    return 0 unless $hlen and $hlen > 0;
    $pos + $hlen > $dataLen and $exifTool->Warn('Truncated Matroska header'), return 1;
    $exifTool->SetFileType();
    SetByteOrder('MM');
    my $tagTablePtr = GetTagTable('Image::ExifTool::Matroska::Main');

    # set flag to process entire file (otherwise we stop at the first Cluster)
    my $verbose = $exifTool->Options('Verbose');
    my $processAll = ($verbose or $exifTool->Options('Unknown') > 1);
    $$exifTool{TrackTypes} = \%trackTypes;  # store Track types reference
    my $oldIndent = $$exifTool{INDENT};
    my $chapterNum = 0;

    # loop over all Matroska elements
    for (;;) {
        while (@dirEnd and $pos + $dataPos >= $dirEnd[-1]) {
            pop @dirEnd;
            # use INDENT to decide whether or not we are done this Track element
            delete $$exifTool{SET_GROUP1} if $trackIndent and $trackIndent eq $$exifTool{INDENT};
            $$exifTool{INDENT} = substr($$exifTool{INDENT}, 0, -2);
        }
        # read more if we are getting close to the end of our buffer
        # (24 more bytes should be enough to read this element header)
        if ($pos + 24 > $dataLen and $raf->Read($buf2, 65536)) {
            $buff = substr($buff, $pos) . $buf2;
            undef $buf2;
            $dataPos += $pos;
            $dataLen = length $buff;
            $pos = 0;
        }
        my $tag = GetVInt($buff, $pos);
        last unless defined $tag and $tag >= 0;
        my $size = GetVInt($buff, $pos);
        my $tagInfo = $exifTool->GetTagInfo($tagTablePtr, $tag);
        # just fall through into the contained EBML elements
        if ($tagInfo and $$tagInfo{SubDirectory}) {
            # stop processing at first cluster unless we are in verbose mode
            last if $$tagInfo{Name} eq 'Cluster' and not $processAll;
            $$exifTool{INDENT} .= '| ';
            $exifTool->VerboseDir($$tagTablePtr{$tag}{Name}, undef, $size);
            push @dirEnd, $pos + $dataPos + $size;
            if ($$tagInfo{Name} eq 'ChapterAtom') {
                $$exifTool{SET_GROUP1} = 'Chapter' . (++$chapterNum);
                $trackIndent = $$exifTool{INDENT};
            }
            next;
        }
        last unless defined $size and $size >= 0;
        if ($pos + $size > $dataLen) {
            # read more data in multiples of 64kB
            my $more = (int(($pos + $size - $dataLen) / 65536) + 1) * 65536;
            if ($raf->Read($buf2, $more)) {
                $buff = substr($buff, $pos) . $buf2;
                undef $buf2;
                $dataPos += $pos;
                $dataLen = length $buff;
                $pos = 0;
            }
            last if $pos + $size > $dataLen;
        }
        unless ($tagInfo) {
            # ignore the element
            $pos += $size;
            next;
        }
        my $val;
        if ($$tagInfo{Format}) {
            my $fmt = $$tagInfo{Format};
            if ($fmt eq 'string' or $fmt eq 'utf8') {
                ($val = substr($buff, $pos, $size)) =~ s/\0.*//s;
                $val = $exifTool->Decode($val, 'UTF8') if $fmt eq 'utf8';
            } elsif ($fmt eq 'float') {
                if ($size == 4) {
                    $val = GetFloat(\$buff, $pos);
                } elsif ($size == 8) {
                    $val = GetDouble(\$buff, $pos);
                } else {
                    $exifTool->Warn("Illegal float size ($size)");
                }
            } else {
                my @vals = unpack("x${pos}C$size", $buff);
                $val = 0;
                if ($fmt eq 'signed' or $fmt eq 'date') {
                    my $over = 1;
                    foreach (@vals) {
                        $val = $val * 256 + $_;
                        $over *= 256;
                    }
                    # interpret negative numbers
                    $val -= $over if $vals[0] & 0x80;
                    # convert dates (nanoseconds since 2001:01:01)
                    if ($fmt eq 'date') {
                        my $t = $val / 1e9;
                        my $f = $t - int($t);   # fractional seconds
                        $f =~ s/^\d+//;         # remove leading zero
                        # (8 leap days between 1970 and 2001)
                        $t += (((2001-1970)*365+8)*24*3600);
                        $val = Image::ExifTool::ConvertUnixTime($t) . $f . 'Z';
                    }
                } else { # must be unsigned
                    $val = $val * 256 + $_ foreach @vals;
                }
            }
            # set group1 to Track/Chapter number
            if ($$tagInfo{Name} eq 'TrackNumber') {
                $$exifTool{SET_GROUP1} = 'Track' . $val;
                $trackIndent = $$exifTool{INDENT};
            }
        }
        my %parms = (
            DataPt  => \$buff,
            DataPos => $dataPos,
            Start   => $pos,
            Size    => $size,
        );
        if ($$tagInfo{NoSave}) {
            $exifTool->VerboseInfo($tag, $tagInfo, Value => $val, %parms) if $verbose;
        } else {
            $exifTool->HandleTag($tagTablePtr, $tag, $val, %parms);
        }
        $pos += $size;  # step to next element
    }
    $$exifTool{INDENT} = $oldIndent;
    delete $$exifTool{SET_GROUP1};
    # override file type if necessary based on existing track types
    unless ($trackTypes{0x01} or $trackTypes{0x03}) {   # video or complex?
        if ($trackTypes{0x02}) {                        # audio?
            $exifTool->OverrideFileType('MKA');
        } elsif ($trackTypes{0x11}) {                   # subtitle?
            $exifTool->OverrideFileType('MKS');
        }
    }
    return 1;
}

1;  # end

__END__

=head1 NAME

Image::ExifTool::Matroska - Read meta information from Matroska files

=head1 SYNOPSIS

This module is used by Image::ExifTool

=head1 DESCRIPTION

This module contains definitions required by Image::ExifTool to read meta
information from Matroska multimedia files (MKA, MKV and MKS).

=head1 AUTHOR

Copyright 2003-2010, 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<http://www.matroska.org/technical/specs/index.html>

=back

=head1 SEE ALSO

L<Image::ExifTool::TagNames/Matroska Tags>,
L<Image::ExifTool(3pm)|Image::ExifTool>

=cut

