123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725 |
- #------------------------------------------------------------------------------
- # File: M2TS.pm
- #
- # Description: Read M2TS (AVCHD) meta information
- #
- # Revisions: 2009/07/03 - P. Harvey Created
- #
- # References: 1) http://neuron2.net/library/mpeg2/iso13818-1.pdf
- # 2) http://www.blu-raydisc.com/Assets/Downloadablefile/BD-RE_Part3_V2.1_WhitePaper_080406-15271.pdf
- # 3) http://www.videohelp.com/forum/archive/reading-avchd-playlist-files-bdmv-playlist-mpl-t358888.html
- # 4) http://en.wikipedia.org/wiki/MPEG_transport_stream
- # 5) http://www.dunod.com/documents/9782100493463/49346_DVB.pdf
- # 6) http://trac.handbrake.fr/browser/trunk/libhb/stream.c
- # 7) http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=04560141
- # 8) http://www.w6rz.net/xport.zip
- #
- # Notes: Variable names containing underlines are the same as in ref 1.
- #
- # Glossary: PES = Packetized Elementary Stream
- # PAT = Program Association Table
- # PMT = Program Map Table
- # PCR = Program Clock Reference
- # PID = Packet Identifier
- #
- # To Do: - parse PCR to obtain average bitrates?
- #------------------------------------------------------------------------------
- package Image::ExifTool::M2TS;
- use strict;
- use vars qw($VERSION);
- use Image::ExifTool qw(:DataAccess :Utils);
- $VERSION = '1.11';
- # program map table "stream_type" lookup (ref 6/1)
- my %streamType = (
- 0x00 => 'Reserved',
- 0x01 => 'MPEG-1 Video',
- 0x02 => 'MPEG-2 Video',
- 0x03 => 'MPEG-1 Audio',
- 0x04 => 'MPEG-2 Audio',
- 0x05 => 'ISO 13818-1 private sections',
- 0x06 => 'ISO 13818-1 PES private data',
- 0x07 => 'ISO 13522 MHEG',
- 0x08 => 'ISO 13818-1 DSM-CC',
- 0x09 => 'ISO 13818-1 auxiliary',
- 0x0A => 'ISO 13818-6 multi-protocol encap',
- 0x0B => 'ISO 13818-6 DSM-CC U-N msgs',
- 0x0C => 'ISO 13818-6 stream descriptors',
- 0x0D => 'ISO 13818-6 sections',
- 0x0E => 'ISO 13818-1 auxiliary',
- 0x0F => 'MPEG-2 AAC Audio',
- 0x10 => 'MPEG-4 Video',
- 0x11 => 'MPEG-4 LATM AAC Audio',
- 0x12 => 'MPEG-4 generic',
- 0x13 => 'ISO 14496-1 SL-packetized',
- 0x14 => 'ISO 13818-6 Synchronized Download Protocol',
- # 0x15-0x7F => 'ISO 13818-1 Reserved',
- 0x1b => 'H.264 Video',
- 0x80 => 'DigiCipher II Video',
- 0x81 => 'A52/AC-3 Audio',
- 0x82 => 'HDMV DTS Audio',
- 0x83 => 'LPCM Audio',
- 0x84 => 'SDDS Audio',
- 0x85 => 'ATSC Program ID',
- 0x86 => 'DTS-HD Audio',
- 0x87 => 'E-AC-3 Audio',
- 0x8a => 'DTS Audio',
- 0x91 => 'A52b/AC-3 Audio',
- 0x92 => 'DVD_SPU vls Subtitle',
- 0x94 => 'SDDS Audio',
- 0xa0 => 'MSCODEC Video',
- 0xea => 'Private ES (VC-1)',
- # 0x80-0xFF => 'User Private',
- );
- # "table_id" values (ref 5)
- my %tableID = (
- 0x00 => 'Program Association',
- 0x01 => 'Conditional Access',
- 0x02 => 'Program Map',
- 0x03 => 'Transport Stream Description',
- 0x40 => 'Actual Network Information',
- 0x41 => 'Other Network Information',
- 0x42 => 'Actual Service Description',
- 0x46 => 'Other Service Description',
- 0x4a => 'Bouquet Association',
- 0x4e => 'Actual Event Information - Present/Following',
- 0x4f => 'Other Event Information - Present/Following',
- 0x50 => 'Actual Event Information - Schedule', #(also 0x51-0x5f)
- 0x60 => 'Other Event Information - Schedule', # (also 0x61-0x6f)
- 0x70 => 'Time/Date',
- 0x71 => 'Running Status',
- 0x72 => 'Stuffing',
- 0x73 => 'Time Offset',
- 0x7e => 'Discontinuity Information',
- 0x7f => 'Selection Information',
- # 0x80-0xfe => 'User Defined',
- );
- # PES stream ID's for which a syntax field does not exist
- my %noSyntax = (
- 0xbc => 1, # program_stream_map
- 0xbe => 1, # padding_stream
- 0xbf => 1, # private_stream_2
- 0xf0 => 1, # ECM_stream
- 0xf1 => 1, # EMM_stream
- 0xf2 => 1, # DSMCC_stream
- 0xf8 => 1, # ITU-T Rec. H.222.1 type E stream
- 0xff => 1, # program_stream_directory
- );
- # information extracted from the MPEG-2 transport stream
- %Image::ExifTool::M2TS::Main = (
- GROUPS => { 2 => 'Video' },
- VARS => { NO_ID => 1 },
- NOTES => q{
- The MPEG-2 transport stream is used as a container for many different
- audio/video formats (including AVCHD). This table lists information
- extracted from M2TS files.
- },
- VideoStreamType => {
- PrintHex => 1,
- PrintConv => \%streamType,
- SeparateTable => 'StreamType',
- },
- AudioStreamType => {
- PrintHex => 1,
- PrintConv => \%streamType,
- SeparateTable => 'StreamType',
- },
- Duration => {
- Notes => q{
- the -fast option may be used to avoid scanning to the end of file to
- calculate the Duration
- },
- ValueConv => '$val / 27000000', # (clock is 27MHz)
- PrintConv => 'ConvertDuration($val)',
- },
- # the following tags are for documentation purposes only
- _AC3 => { SubDirectory => { TagTable => 'Image::ExifTool::M2TS::AC3' } },
- _H264 => { SubDirectory => { TagTable => 'Image::ExifTool::H264::Main' } },
- );
- # information extracted from AC-3 audio streams
- %Image::ExifTool::M2TS::AC3 = (
- GROUPS => { 1 => 'AC3', 2 => 'Audio' },
- VARS => { NO_ID => 1 },
- NOTES => 'Tags extracted from AC-3 audio streams.',
- AudioSampleRate => {
- PrintConv => {
- 0 => '48000',
- 1 => '44100',
- 2 => '32000',
- },
- },
- AudioBitrate => {
- PrintConvColumns => 2,
- ValueConv => {
- 0 => 32000,
- 1 => 40000,
- 2 => 48000,
- 3 => 56000,
- 4 => 64000,
- 5 => 80000,
- 6 => 96000,
- 7 => 112000,
- 8 => 128000,
- 9 => 160000,
- 10 => 192000,
- 11 => 224000,
- 12 => 256000,
- 13 => 320000,
- 14 => 384000,
- 15 => 448000,
- 16 => 512000,
- 17 => 576000,
- 18 => 640000,
- 32 => '32000 max',
- 33 => '40000 max',
- 34 => '48000 max',
- 35 => '56000 max',
- 36 => '64000 max',
- 37 => '80000 max',
- 38 => '96000 max',
- 39 => '112000 max',
- 40 => '128000 max',
- 41 => '160000 max',
- 42 => '192000 max',
- 43 => '224000 max',
- 44 => '256000 max',
- 45 => '320000 max',
- 46 => '384000 max',
- 47 => '448000 max',
- 48 => '512000 max',
- 49 => '576000 max',
- 50 => '640000 max',
- },
- PrintConv => 'ConvertBitrate($val)',
- },
- SurroundMode => {
- PrintConv => {
- 0 => 'Not indicated',
- 1 => 'Not Dolby surround',
- 2 => 'Dolby surround',
- },
- },
- AudioChannels => {
- PrintConvColumns => 2,
- PrintConv => {
- 0 => '1 + 1',
- 1 => 1,
- 2 => 2,
- 3 => 3,
- 4 => '2/1',
- 5 => '3/1',
- 6 => '2/2',
- 7 => '3/2',
- 8 => 1,
- 9 => '2 max',
- 10 => '3 max',
- 11 => '4 max',
- 12 => '5 max',
- 13 => '6 max',
- },
- },
- );
- #------------------------------------------------------------------------------
- # Extract information from AC-3 audio stream
- # Inputs: 0) ExifTool ref, 1) data ref
- # Reference: http://www.atsc.org/standards/a_52b.pdf
- sub ParseAC3Audio($$)
- {
- my ($et, $dataPt) = @_;
- if ($$dataPt =~ /\x0b\x77..(.)/sg) {
- my $sampleRate = ord($1) >> 6;
- my $tagTablePtr = GetTagTable('Image::ExifTool::M2TS::AC3');
- $et->HandleTag($tagTablePtr, AudioSampleRate => $sampleRate);
- }
- }
- #------------------------------------------------------------------------------
- # Extract information from AC-3 stream descriptor
- # Inputs: 0) ExifTool ref, 1) data ref
- # Reference: http://www.atsc.org/standards/a_52b.pdf
- # Note: This information is duplicated in the Audio stream, but it
- # is somewhat easier to extract it from the descriptor instead
- sub ParseAC3Descriptor($$)
- {
- my ($et, $dataPt) = @_;
- return if length $$dataPt < 3;
- my @v = unpack('C3', $$dataPt);
- my $tagTablePtr = GetTagTable('Image::ExifTool::M2TS::AC3');
- # $et->HandleTag($tagTablePtr, 'AudioSampleRate', $v[0] >> 5);
- $et->HandleTag($tagTablePtr, 'AudioBitrate', $v[1] >> 2);
- $et->HandleTag($tagTablePtr, 'SurroundMode', $v[1] & 0x03);
- $et->HandleTag($tagTablePtr, 'AudioChannels', ($v[2] >> 1) & 0x0f);
- # don't (yet) decode any more (language codes, etc)
- }
- #------------------------------------------------------------------------------
- # Parse PID stream data
- # Inputs: 0) Exiftool ref, 1) PID number, 2) PID type, 3) PID name, 4) data ref
- # Returns: 0=stream parsed OK,
- # 1=stream parsed but we want to parse more of these,
- # -1=can't parse yet because we don't know the type
- sub ParsePID($$$$$)
- {
- my ($et, $pid, $type, $pidName, $dataPt) = @_;
- # can't parse until we know the type (Program Map Table may be later in the stream)
- return -1 unless defined $type;
- my $verbose = $et->Options('Verbose');
- if ($verbose > 1) {
- my $out = $et->Options('TextOut');
- printf $out "Parsing stream 0x%.4x (%s)\n", $pid, $pidName;
- my %parms = ( Out => $out );
- $parms{MaxLen} = 96 if $verbose < 4;
- HexDump($dataPt, undef, %parms) if $verbose > 2;
- }
- my $more = 0;
- if ($type == 0x01 or $type == 0x02) {
- # MPEG-1/MPEG-2 Video
- require Image::ExifTool::MPEG;
- Image::ExifTool::MPEG::ParseMPEGAudioVideo($et, $dataPt);
- } elsif ($type == 0x03 or $type == 0x04) {
- # MPEG-1/MPEG-2 Audio
- require Image::ExifTool::MPEG;
- Image::ExifTool::MPEG::ParseMPEGAudio($et, $dataPt);
- } elsif ($type == 0x1b) {
- # H.264 Video
- require Image::ExifTool::H264;
- $more = Image::ExifTool::H264::ParseH264Video($et, $dataPt);
- # force parsing additional H264 frames with ExtractEmbedded option
- $more = 1 if $et->Options('ExtractEmbedded');
- } elsif ($type == 0x81 or $type == 0x87 or $type == 0x91) {
- # AC-3 audio
- ParseAC3Audio($et, $dataPt);
- }
- return $more;
- }
- #------------------------------------------------------------------------------
- # Extract information from a M2TS file
- # Inputs: 0) ExifTool object reference, 1) DirInfo reference
- # Returns: 1 on success, 0 if this wasn't a valid M2TS file
- sub ProcessM2TS($$)
- {
- my ($et, $dirInfo) = @_;
- my $raf = $$dirInfo{RAF};
- my ($buff, $pLen, $upkPrefix, $j, $fileType, $eof);
- my (%pmt, %pidType, %data, %sectLen);
- my ($startTime, $endTime, $backScan, $maxBack);
- my $verbose = $et->Options('Verbose');
- my $out = $et->Options('TextOut');
- # read first packet
- return 0 unless $raf->Read($buff, 8) == 8;
- # test for magic number (sync byte is the only thing we can safely check)
- return 0 unless $buff =~ /^(....)?\x47/s;
- unless ($1) {
- $pLen = 188; # no timecode
- $fileType = 'M2T'; # (just as a way to tell there is no timecode)
- $upkPrefix = 'N';
- } else {
- $pLen = 192; # 188-byte transport packet + leading 4-byte timecode (ref 4)
- $upkPrefix = 'x4N';
- }
- $et->SetFileType($fileType);
- SetByteOrder('MM');
- $raf->Seek(0,0); # rewind to start
- my $tagTablePtr = GetTagTable('Image::ExifTool::M2TS::Main');
- # PID lookup strings (will add to this with entries from program map table)
- my %pidName = (
- 0 => 'Program Association Table',
- 1 => 'Conditional Access Table',
- 2 => 'Transport Stream Description Table',
- 0x1fff => 'Null Packet',
- );
- my %didPID = ( 1 => 0, 2 => 0, 0x1fff => 0 );
- my %needPID = ( 0 => 1 ); # lookup for stream PID's that we still need to parse
- my $prePos = $pLen - 188; # byte position of packet prefix
- my $readSize = 64 * $pLen; # read 64 packets at once
- my $pEnd = 0;
- my $i = 0;
- $buff = '';
- # parse packets from MPEG-2 Transport Stream
- for (;;) {
- unless (%needPID) {
- last unless defined $startTime;
- # seek backwards to find last PCR
- if (defined $backScan) {
- last if defined $endTime;
- $backScan -= $pLen;
- last if $backScan < $maxBack;
- } else {
- undef $endTime;
- last if $et->Options('FastScan');
- $verbose and print "[Starting backscan for last PCR]\n";
- # calculate position of last complete packet
- my $fwdPos = $raf->Tell();
- $raf->Seek(0, 2) or last;
- my $fsize = $raf->Tell();
- my $nPack = int($fsize / $pLen);
- $backScan = ($nPack - 1) * $pLen - $fsize;
- # set limit on how far back we will go
- $maxBack = $fwdPos - $fsize;
- $maxBack = -256000 if $maxBack < -256000;
- }
- $raf->Seek($backScan, 2) or last;
- }
- my $pos = $pEnd;
- # read more if necessary
- if ($pos + $pLen > length $buff) {
- $raf->Read($buff, $readSize) >= $pLen or $eof = 1, last;
- $pos = $pEnd = 0;
- }
- $pEnd += $pLen;
- # decode the packet prefix
- $pos += $prePos;
- my $prefix = unpack("x${pos}N", $buff); # (use unpack instead of Get32u for speed)
- # validate sync byte
- unless (($prefix & 0xff000000) == 0x47000000) {
- $et->Warn('Synchronization error') unless defined $backScan;
- last;
- }
- # my $transport_error_indicator = $prefix & 0x00800000;
- my $payload_unit_start_indicator = $prefix & 0x00400000;
- # my $transport_priority = $prefix & 0x00200000;
- my $pid =($prefix & 0x001fff00) >> 8; # packet ID
- # my $transport_scrambling_control = $prefix & 0x000000c0;
- my $adaptation_field_exists = $prefix & 0x00000020;
- my $payload_data_exists = $prefix & 0x00000010;
- # my $continuity_counter = $prefix & 0x0000000f;
- if ($verbose > 1) {
- print $out "Transport packet $i:\n";
- ++$i;
- HexDump(\$buff, $pLen, Addr => $i * $pLen, Out => $out,
- Start => $pos - $prePos) if $verbose > 2;
- my $str = $pidName{$pid} ? " ($pidName{$pid})" : '';
- printf $out " Timecode: 0x%.4x\n", Get32u(\$buff, 0) if $pLen == 192;
- printf $out " Packet ID: 0x%.4x$str\n", $pid;
- printf $out " Start Flag: %s\n", $payload_unit_start_indicator ? 'Yes' : 'No';
- }
- $pos += 4;
- # handle adaptation field
- if ($adaptation_field_exists) {
- my $len = Get8u(\$buff, $pos++);
- $pos + $len > $pEnd and $et->Warn('Invalid adaptation field length'), last;
- # read PCR value for calculation of Duration
- if ($len > 6) {
- my $flags = Get8u(\$buff, $pos);
- if ($flags & 0x10) { # PCR_flag
- # combine 33-bit program_clock_reference_base and 9-bit extension
- my $pcrBase = Get32u(\$buff, $pos + 1);
- my $pcrExt = Get16u(\$buff, $pos + 5);
- # ignore separate programs (PID's) and store just the
- # first and last timestamps found in the file (is this OK?)
- $endTime = 300 * (2 * $pcrBase + ($pcrExt >> 15)) + ($pcrExt & 0x01ff);
- $startTime = $endTime unless defined $startTime;
- }
- }
- $pos += $len;
- }
- # all done with this packet unless it carries a payload
- # or if we are just looking for the last timestamp
- next unless $payload_data_exists and not defined $backScan;
- # decode payload data
- if ($pid == 0 or # program association table
- defined $pmt{$pid}) # program map table(s)
- {
- # must interpret pointer field if payload_unit_start_indicator is set
- my $buf2;
- if ($payload_unit_start_indicator) {
- # skip to start of section
- my $pointer_field = Get8u(\$buff, $pos);
- $pos += 1 + $pointer_field;
- $pos >= $pEnd and $et->Warn('Bad pointer field'), last;
- $buf2 = substr($buff, $pEnd-$pLen, $pLen);
- $pos -= $pEnd - $pLen;
- } else {
- # not the start of a section
- next unless $sectLen{$pid};
- my $more = $sectLen{$pid} - length($data{$pid});
- my $size = $pLen - $pos;
- $size = $more if $size > $more;
- $data{$pid} .= substr($buff, $pos, $size);
- next unless $size == $more;
- # we have the complete section now, so put into $buf2 for parsing
- $buf2 = $data{$pid};
- $pos = 0;
- delete $data{$pid};
- delete $sectLen{$pid};
- }
- my $slen = length($buf2); # section length
- $pos + 8 > $slen and $et->Warn("Truncated payload"), last;
- # validate table ID
- my $table_id = Get8u(\$buf2, $pos);
- my $name = ($tableID{$table_id} || sprintf('Unknown (0x%x)',$table_id)) . ' Table';
- my $expectedID = $pid ? 0x02 : 0x00;
- unless ($table_id == $expectedID) {
- $verbose > 1 and print $out " (skipping $name)\n";
- delete $needPID{$pid};
- $didPID{$pid} = 1;
- next;
- }
- # validate section syntax indicator for parsed tables (PAT, PMT)
- my $section_syntax_indicator = Get8u(\$buf2, $pos + 1) & 0xc0;
- $section_syntax_indicator == 0x80 or $et->Warn("Bad $name"), last;
- my $section_length = Get16u(\$buf2, $pos + 1) & 0x0fff;
- $section_length > 1021 and $et->Warn("Invalid $name length"), last;
- if ($slen < $section_length + 3) { # (3 bytes for table_id + section_length)
- # must wait until we have the full section
- $data{$pid} = substr($buf2, $pos);
- $sectLen{$pid} = $section_length + 3;
- next;
- }
- my $program_number = Get16u(\$buf2, $pos + 3);
- my $section_number = Get8u(\$buf2, $pos + 6);
- my $last_section_number = Get8u(\$buf2, $pos + 7);
- if ($verbose > 1) {
- print $out " $name length: $section_length\n";
- print $out " Program No: $program_number\n" if $pid;
- printf $out " Stream ID: 0x%x\n", $program_number if not $pid;
- print $out " Section No: $section_number\n";
- print $out " Last Sect.: $last_section_number\n";
- }
- my $end = $pos + $section_length + 3 - 4; # (don't read 4-byte CRC)
- $pos += 8;
- if ($pid == 0) {
- # decode PAT (Program Association Table)
- while ($pos <= $end - 4) {
- my $program_number = Get16u(\$buf2, $pos);
- my $program_map_PID = Get16u(\$buf2, $pos + 2) & 0x1fff;
- $pmt{$program_map_PID} = $program_number; # save our PMT PID's
- my $str = "Program $program_number Map";
- $pidName{$program_map_PID} = $str;
- $needPID{$program_map_PID} = 1 unless $didPID{$program_map_PID};
- $verbose and printf $out " PID(0x%.4x) --> $str\n", $program_map_PID;
- $pos += 4;
- }
- } else {
- # decode PMT (Program Map Table)
- $pos + 4 > $slen and $et->Warn('Truncated PMT'), last;
- my $pcr_pid = Get16u(\$buf2, $pos) & 0x1fff;
- my $program_info_length = Get16u(\$buf2, $pos + 2) & 0x0fff;
- my $str = "Program $program_number Clock Reference";
- $pidName{$pcr_pid} = $str;
- $verbose and printf $out " PID(0x%.4x) --> $str\n", $pcr_pid;
- $pos += 4;
- $pos + $program_info_length > $slen and $et->Warn('Truncated program info'), last;
- # dump program information descriptors if verbose
- if ($verbose > 1) { for ($j=0; $j<$program_info_length-2; ) {
- my $descriptor_tag = Get8u(\$buf2, $pos + $j);
- my $descriptor_length = Get8u(\$buf2, $pos + $j + 1);
- $j += 2;
- last if $j + $descriptor_length > $program_info_length;
- my $desc = substr($buf2, $pos+$j, $descriptor_length);
- $j += $descriptor_length;
- $desc =~ s/([\x00-\x1f\x80-\xff])/sprintf("\\x%.2x",ord $1)/eg;
- printf $out " Program Descriptor: Type=0x%.2x \"$desc\"\n", $descriptor_tag;
- }}
- $pos += $program_info_length; # skip descriptors (for now)
- while ($pos <= $end - 5) {
- my $stream_type = Get8u(\$buf2, $pos);
- my $elementary_pid = Get16u(\$buf2, $pos + 1) & 0x1fff;
- my $es_info_length = Get16u(\$buf2, $pos + 3) & 0x0fff;
- my $str = $streamType{$stream_type};
- $str or $str = ($stream_type < 0x7f ? 'Reserved' : 'Private');
- $str = sprintf('%s (0x%.2x)', $str, $stream_type);
- $str = "Program $program_number $str";
- $verbose and printf $out " PID(0x%.4x) --> $str\n", $elementary_pid;
- if ($str =~ /(Audio|Video)/) {
- unless ($pidName{$elementary_pid}) {
- $et->HandleTag($tagTablePtr, $1 . 'StreamType', $stream_type)
- }
- # we want to parse all Audio and Video streams
- $needPID{$elementary_pid} = 1 unless $didPID{$elementary_pid};
- }
- # save PID type and name string
- $pidName{$elementary_pid} = $str;
- $pidType{$elementary_pid} = $stream_type;
- $pos += 5;
- $pos + $es_info_length > $slen and $et->Warn('Trunacted ES info'), $pos = $end, last;
- # parse elementary stream descriptors
- for ($j=0; $j<$es_info_length-2; ) {
- my $descriptor_tag = Get8u(\$buf2, $pos + $j);
- my $descriptor_length = Get8u(\$buf2, $pos + $j + 1);
- $j += 2;
- last if $j + $descriptor_length > $es_info_length;
- my $desc = substr($buf2, $pos+$j, $descriptor_length);
- $j += $descriptor_length;
- if ($verbose > 1) {
- my $dstr = $desc;
- $dstr =~ s/([\x00-\x1f\x80-\xff])/sprintf("\\x%.2x",ord $1)/eg;
- printf $out " ES Descriptor: Type=0x%.2x \"$dstr\"\n", $descriptor_tag;
- }
- # parse type-specific descriptor information (once)
- unless ($didPID{$pid}) {
- if ($descriptor_tag == 0x81) { # AC-3
- ParseAC3Descriptor($et, \$desc);
- }
- }
- }
- $pos += $es_info_length;
- }
- }
- # $pos = $end + 4; # skip CRC
- } elsif (not defined $didPID{$pid}) {
- # save data from the start of each elementary stream
- if ($payload_unit_start_indicator) {
- if (defined $data{$pid}) {
- # we must have a whole section, so parse now
- my $more = ParsePID($et, $pid, $pidType{$pid}, $pidName{$pid}, \$data{$pid});
- # start fresh even if we couldn't process this PID yet
- delete $data{$pid};
- unless ($more) {
- delete $needPID{$pid};
- $didPID{$pid} = 1;
- next;
- }
- # set flag indicating we found this PID but we still want more
- $needPID{$pid} = -1;
- }
- # check for a PES header
- next if $pos + 6 > $pEnd;
- my $start_code = Get32u(\$buff, $pos);
- next unless ($start_code & 0xffffff00) == 0x00000100;
- my $stream_id = $start_code & 0xff;
- if ($verbose > 1) {
- my $pes_packet_length = Get16u(\$buff, $pos + 4);
- printf $out " Stream ID: 0x%.2x\n", $stream_id;
- print $out " Packet Len: $pes_packet_length\n";
- }
- $pos += 6;
- unless ($noSyntax{$stream_id}) {
- next if $pos + 3 > $pEnd;
- # validate PES syntax
- my $syntax = Get8u(\$buff, $pos) & 0xc0;
- $syntax == 0x80 or $et->Warn('Bad PES syntax'), next;
- # skip PES header
- my $pes_header_data_length = Get8u(\$buff, $pos + 2);
- $pos += 3 + $pes_header_data_length;
- next if $pos >= $pEnd;
- }
- $data{$pid} = substr($buff, $pos, $pEnd-$pos);
- } else {
- next unless defined $data{$pid};
- # accumulate data for each elementary stream
- $data{$pid} .= substr($buff, $pos, $pEnd-$pos);
- }
- # save only the first 256 bytes of most streams, except for
- # unknown or H.264 streams where we save 1 kB
- my $saveLen = (not $pidType{$pid} or $pidType{$pid} == 0x1b) ? 1024 : 256;
- if (length($data{$pid}) >= $saveLen) {
- my $more = ParsePID($et, $pid, $pidType{$pid}, $pidName{$pid}, \$data{$pid});
- next if $more < 0; # wait for program map table (hopefully not too long)
- delete $data{$pid};
- $more and $needPID{$pid} = -1, next; # parse more of these
- delete $needPID{$pid};
- $didPID{$pid} = 1;
- }
- next;
- }
- if ($needPID{$pid}) {
- # we found and parsed a section with this PID, so
- # delete from the lookup of PID's we still need to parse
- delete $needPID{$pid};
- $didPID{$pid} = 1;
- }
- }
- # calculate Duration if available
- if (defined $startTime and defined $endTime and $startTime != $endTime) {
- $endTime += 0x80000000 * 1200 if $startTime > $endTime; # handle 33-bit wrap
- $et->HandleTag($tagTablePtr, 'Duration', $endTime - $startTime);
- }
- if ($verbose) {
- my @need;
- foreach (keys %needPID) {
- push @need, sprintf('0x%.2x',$_) if $needPID{$_} > 0;
- }
- if (@need) {
- @need = sort @need;
- print $out "End of file. Missing PID(s): @need\n";
- } else {
- my $what = $eof ? 'of file' : 'scan';
- print $out "End $what. All PID's parsed.\n";
- }
- }
- # parse any remaining partial PID streams
- my $pid;
- foreach $pid (sort keys %data) {
- ParsePID($et, $pid, $pidType{$pid}, $pidName{$pid}, \$data{$pid});
- delete $data{$pid};
- }
- return 1;
- }
- 1; # end
- __END__
- =head1 NAME
- Image::ExifTool::M2TS - Read M2TS (AVCHD) meta information
- =head1 SYNOPSIS
- This module is used by Image::ExifTool
- =head1 DESCRIPTION
- This module contains routines required by Image::ExifTool to extract
- information from MPEG-2 transport streams, such as those used by AVCHD
- video.
- =head1 AUTHOR
- Copyright 2003-2016, 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://neuron2.net/library/mpeg2/iso13818-1.pdf>
- =item L<http://www.blu-raydisc.com/Assets/Downloadablefile/BD-RE_Part3_V2.1_WhitePaper_080406-15271.pdf>
- =item L<http://www.videohelp.com/forum/archive/reading-avchd-playlist-files-bdmv-playlist-mpl-t358888.html>
- =item L<http://en.wikipedia.org/wiki/MPEG_transport_stream>
- =item L<http://www.dunod.com/documents/9782100493463/49346_DVB.pdf>
- =item L<http://trac.handbrake.fr/browser/trunk/libhb/stream.c>
- =item L<http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=04560141>
- =item L<http://www.w6rz.net/xport.zip>
- =back
- =head1 SEE ALSO
- L<Image::ExifTool::TagNames/M2TS Tags>,
- L<Image::ExifTool(3pm)|Image::ExifTool>
- =cut
|