#------------------------------------------------------------------------------
# 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 = '1.13';
# 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';
}
my $prePos = $pLen - 188; # byte position of packet prefix
my $readSize = 64 * $pLen; # read 64 packets at once
$raf->Seek(0,0); # rewind to start
$raf->Read($buff, $readSize) >= $pLen * 4 or return 0; # require at least 4 packets
# validate the sync byte in the next 3 packets
for ($j=1; $j<4; ++$j) {
return 0 unless substr($buff, $prePos + $pLen * $j, 1) eq 'G'; # (0x47)
}
$et->SetFileType($fileType);
SetByteOrder('MM');
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 $pEnd = 0;
my $i = 0;
# 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, $pos - $prePos) 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('Truncated 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 2003-2017, 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