#------------------------------------------------------------------------------
# File: Audible.pm
#
# Description: Read metadata from Audible audio books
#
# Revisions: 2015/04/05 - P. Harvey Created
#
# References: 1) https://github.com/jteeuwen/audible
# 2) https://code.google.com/p/pyaudibletags/
# 3) http://wiki.multimedia.cx/index.php?title=Audible_Audio
#------------------------------------------------------------------------------
package Image::ExifTool::Audible;
use strict;
use vars qw($VERSION);
use Image::ExifTool qw(:DataAccess :Utils);
$VERSION = '1.02';
sub ProcessAudible_meta($$$);
sub ProcessAudible_cvrx($$$);
%Image::ExifTool::Audible::Main = (
GROUPS => { 2 => 'Audio' },
NOTES => q{
ExifTool will extract any information found in the metadata dictionary of
Audible .AA files, even if not listed in the table below.
},
# tags found in the metadata dictionary (chunk 2)
pubdate => { Name => 'PublishDate', Groups => { 2 => 'Time' } },
pub_date_start => { Name => 'PublishDateStart', Groups => { 2 => 'Time' } },
author => { Name => 'Author', Groups => { 2 => 'Author' } },
copyright => { Name => 'Copyright', Groups => { 2 => 'Author' } },
# also seen (ref PH):
# product_id, parent_id, title, provider, narrator, price, description,
# long_description, short_title, is_aggregation, title_id, codec, HeaderSeed,
# EncryptedBlocks, HeaderKey, license_list, CPUType, license_count, <12 hex digits>,
# parent_short_title, parent_title, aggregation_id, short_description, user_alias
# information extracted from other chunks
_chapter_count => { Name => 'ChapterCount' }, # from chunk 6
_cover_art => { # from chunk 11
Name => 'CoverArt',
Groups => { 2 => 'Preview' },
Binary => 1,
},
);
# 'tags' atoms observed in Audible .m4b audio books (ref PH)
%Image::ExifTool::Audible::tags = (
GROUPS => { 0 => 'QuickTime', 2 => 'Audio' },
NOTES => 'Information found in "tags" atom of Audible M4B audio books.',
meta => {
Name => 'Audible_meta',
SubDirectory => { TagTable => 'Image::ExifTool::Audible::meta' },
},
cvrx => {
Name => 'Audible_cvrx',
SubDirectory => { TagTable => 'Image::ExifTool::Audible::cvrx' },
},
tseg => {
Name => 'Audible_tseg',
SubDirectory => { TagTable => 'Image::ExifTool::Audible::tseg' },
},
);
# 'meta' information observed in Audible .m4b audio books (ref PH)
%Image::ExifTool::Audible::meta = (
PROCESS_PROC => \&ProcessAudible_meta,
GROUPS => { 0 => 'QuickTime', 2 => 'Audio' },
NOTES => 'Information found in Audible M4B "meta" atom.',
Album => 'Album',
ALBUMARTIST => { Name => 'AlbumArtist', Groups => { 2 => 'Author' } },
Artist => { Name => 'Artist', Groups => { 2 => 'Author' } },
Comment => 'Comment',
Genre => 'Genre',
itunesmediatype => { Name => 'iTunesMediaType', Description => 'iTunes Media Type' },
SUBTITLE => 'Subtitle',
Title => 'Title',
TOOL => 'CreatorTool',
Year => { Name => 'Year', Groups => { 2 => 'Time' } },
track => 'ChapterName', # (found in 'meta' of 'tseg' atom)
);
# 'cvrx' information observed in Audible .m4b audio books (ref PH)
%Image::ExifTool::Audible::cvrx = (
PROCESS_PROC => \&ProcessAudible_cvrx,
GROUPS => { 0 => 'QuickTime', 2 => 'Audio' },
NOTES => 'Audible cover art information in M4B audio books.',
VARS => { NO_ID => 1 },
CoverArtType => 'CoverArtType',
CoverArt => {
Name => 'CoverArt',
Groups => { 2 => 'Preview' },
Binary => 1,
},
);
# 'tseg' information observed in Audible .m4b audio books (ref PH)
%Image::ExifTool::Audible::tseg = (
GROUPS => { 0 => 'QuickTime', 2 => 'Audio' },
tshd => {
Name => 'ChapterNumber',
Format => 'int32u',
ValueConv => '$val + 1', # start counting from 1
},
meta => {
Name => 'Audible_meta2',
SubDirectory => { TagTable => 'Image::ExifTool::Audible::meta' },
},
);
#------------------------------------------------------------------------------
# Process Audible 'meta' tags from M4B files (ref PH)
# Inputs: 0) ExifTool object ref, 1) dirInfo ref, 2) tag table ref
# Returns: 1 on success
sub ProcessAudible_meta($$$)
{
my ($et, $dirInfo, $tagTablePtr) = @_;
my $dataPt = $$dirInfo{DataPt};
my $dataPos = $$dirInfo{DataPos};
my $dirLen = length $$dataPt;
return 0 if $dirLen < 4;
my $num = Get32u($dataPt, 0);
$et->VerboseDir('Audible_meta', $num);
my $pos = 4;
my $index;
for ($index=0; $index<$num; ++$index) {
last if $pos + 3 > $dirLen;
my $unk = Get8u($dataPt, $pos); # ? (0x80 or 0x00)
last unless $unk eq 0x80 or $unk eq 0x00;
my $len = Get16u($dataPt, $pos + 1); # tag length
$pos += 3;
last if $pos + $len + 6 > $dirLen or not $len;
my $tag = substr($$dataPt, $pos, $len); # tag ID
my $ver = Get16u($dataPt, $pos + $len); # version?
last unless $ver eq 0x0001;
my $size = Get32u($dataPt, $pos + $len + 2);# data size
$pos += $len + 6;
last if $pos + $size > $dirLen;
my $val = $et->Decode(substr($$dataPt, $pos, $size), 'UTF8');
unless ($$tagTablePtr{$tag}) {
my $name = Image::ExifTool::MakeTagName(($tag =~ /[a-z]/) ? $tag : lc($tag));
AddTagToTable($tagTablePtr, $tag, { Name => $name });
}
$et->HandleTag($tagTablePtr, $tag, $val,
DataPt => $dataPt,
DataPos => $dataPos,
Start => $pos,
Size => $size,
Index => $index,
);
$pos += $size;
}
return 1;
}
#------------------------------------------------------------------------------
# Process Audible 'cvrx' cover art atom from M4B files (ref PH)
# Inputs: 0) ExifTool object ref, 1) dirInfo ref, 2) tag table ref
# Returns: 1 on success
sub ProcessAudible_cvrx($$$)
{
my ($et, $dirInfo, $tagTablePtr) = @_;
my $dataPt = $$dirInfo{DataPt};
my $dataPos = $$dirInfo{DataPos};
my $dirLen = length $$dataPt;
return 0 if 0x0a > $dirLen;
my $len = Get16u($dataPt, 0x08);
return 0 if 0x0a + $len + 6 > $dirLen;
my $size = Get32u($dataPt, 0x0a + $len + 2);
return 0 if 0x0a + $len + 6 + $size > $dirLen;
$et->VerboseDir('Audible_cvrx', undef, $dirLen);
$et->HandleTag($tagTablePtr, 'CoverArtType', undef,
DataPt => $dataPt,
DataPos => $dataPos,
Start => 0x0a,
Size => $len,
);
$et->HandleTag($tagTablePtr, 'CoverArt', undef,
DataPt => $dataPt,
DataPos => $dataPos,
Start => 0x0a + $len + 6,
Size => $size,
);
return 1;
}
#------------------------------------------------------------------------------
# Read information from an Audible .AA file
# Inputs: 0) ExifTool ref, 1) dirInfo ref
# Returns: 1 on success, 0 if this wasn't a valid AA file
sub ProcessAA($$)
{
my ($et, $dirInfo) = @_;
my $raf = $$dirInfo{RAF};
my ($buff, $toc, $entry, $i);
# check magic number
return 0 unless $raf->Read($buff, 16) == 16 and $buff=~/^.{4}\x57\x90\x75\x36/s;
# check file size
if (defined $$et{VALUE}{FileSize}) {
# first 4 bytes of the file should be the filesize
unpack('N', $buff) == $$et{VALUE}{FileSize} or return 0;
}
$et->SetFileType();
SetByteOrder('MM');
my $bytes = 12 * Get32u(\$buff, 8); # table of contents size in bytes
$bytes > 0xc00 and $et->Warn('Invalid TOC'), return 1;
# read the table of contents
$raf->Read($toc, $bytes) == $bytes or $et->Warn('Truncated TOC'), return 1;
my $tagTablePtr = GetTagTable('Image::ExifTool::Audible::Main');
# parse table of contents (in $toc)
for ($entry=0; $entry<$bytes; $entry+=12) {
my $type = Get32u(\$toc, $entry);
next unless $type == 2 or $type == 6 or $type == 11;
my $offset = Get32u(\$toc, $entry + 4);
my $length = Get32u(\$toc, $entry + 8) or next;
$raf->Seek($offset, 0) or $et->Warn("Chunk $type seek error"), last;
if ($type == 6) { # offset table
next if $length < 4 or $raf->Read($buff, 4) != 4; # only read the chapter count
$et->HandleTag($tagTablePtr, '_chapter_count', Get32u(\$buff, 0));
next;
}
# read the chunk
$length > 100000000 and $et->Warn("Chunk $type too big"), next;
$raf->Read($buff, $length) == $length or $et->Warn("Chunk $type read error"), last;
if ($type == 11) { # cover art
next if $length < 8;
my $len = Get32u(\$buff, 0);
my $off = Get32u(\$buff, 4);
next if $off < $offset + 8 or $off - $offset + $len > $length;
$et->HandleTag($tagTablePtr, '_cover_art', substr($buff, $off-$offset, $len));
next;
}
# parse metadata dictionary (in $buff)
$length < 4 and $et->Warn('Bad dictionary'), next;
my $num = Get32u(\$buff, 0);
$num > 0x200 and $et->Warn('Bad dictionary count'), next;
my $pos = 4; # dictionary starts immediately after count
require Image::ExifTool::HTML; # (for UnescapeHTML)
$et->VerboseDir('Audible Metadata', $num);
for ($i=0; $i<$num; ++$i) {
my $tagPos = $pos + 9; # position of tag string
$tagPos > $length and $et->Warn('Truncated dictionary'), last;
# (1 unknown byte ignored at start of each dictionary entry)
my $tagLen = Get32u(\$buff, $pos + 1); # tag string length
my $valLen = Get32u(\$buff, $pos + 5); # value string length
my $valPos = $tagPos + $tagLen; # position of value string
my $nxtPos = $valPos + $valLen; # position of next entry
$nxtPos > $length and $et->Warn('Bad dictionary entry'), last;
my $tag = substr($buff, $tagPos, $tagLen);
my $val = substr($buff, $valPos, $valLen);
unless ($$tagTablePtr{$tag}) {
my $name = Image::ExifTool::MakeTagName($tag);
$name =~ s/_(.)/\U$1/g; # change from underscore-separated to mixed case
AddTagToTable($tagTablePtr, $tag, { Name => $name });
}
# unescape HTML character references and convert from UTF-8
$val = $et->Decode(Image::ExifTool::HTML::UnescapeHTML($val), 'UTF8');
$et->HandleTag($tagTablePtr, $tag, $val,
DataPos => $offset,
DataPt => \$buff,
Start => $valPos,
Size => $valLen,
Index => $i,
);
$pos = $nxtPos; # step to next dictionary entry
}
}
return 1;
}
1; # end
__END__
=head1 NAME
Image::ExifTool::Audible - Read meta information from Audible audio books
=head1 SYNOPSIS
This module is used by Image::ExifTool
=head1 DESCRIPTION
This module contains definitions required by Image::ExifTool to read meta
information from Audible audio books.
=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<https://github.com/jteeuwen/audible>
=item L<https://code.google.com/p/pyaudibletags/>
=item L<http://wiki.multimedia.cx/index.php?title=Audible_Audio>
=back
=head1 SEE ALSO
L<Image::ExifTool::TagNames/Audible Tags>,
L<Image::ExifTool(3pm)|Image::ExifTool>
=cut