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|
## ----------------------------------------------------------------------------
# Tools::ID3Tag.
# -----------------------------------------------------------------------------
# Mastering programmed by YAMASHINA Hio
#
# Copyright 2008 YAMASHINA Hio
# -----------------------------------------------------------------------------
# $Id: ID3Tag.pm 15704 2008-07-12 12:31:42Z hio $
# -----------------------------------------------------------------------------
package Tools::ID3Tag;
use strict;
use warnings;
use Unicode::Japanese;
our $VERSION = '0.01';
1;
# -----------------------------------------------------------------------------
# $info = $pkg->extract($content).
# $info->{version} = "2.x.x";
# $info->{title} = $title | undef;
# $info->{artist} = $artist | undef;
# $info->{album} = $album | undef;
#
sub extract
{
my $pkg = shift;
my $content = shift;
if( $content !~ m{^ID3(.{7})}s )
{
return;
}
# ID3v2 tag.
my ($major, $minor, $flags, $size) = unpack("CCCN", $1);
my $ver = "2.$major.$minor";
my $is_unsync = $flags & (1 << 7);
my $has_ex_header = ($flags & (1 << 6)) && ($major >= 3);
my $has_expermental = $flags & (1 << 5);
my $has_footer = $flags & (1 << 4);
#$DEBUG and print "id3v2: version=$ver, flags=".(sprintf("%x",$flags)).", ex=".($has_ex_header?"yes":"no").", footer=".($has_footer?"yes":"no")."\n";
if( $size < length($content) )
{
$content = substr($content, 0, $size);
}
my $offset = 10;
my $info = {
version => $ver,
size => $size,
title => undef,
artist => undef,
album => undef,
};
my $old_frameid = {
TT2 => 'TIT2',
TP1 => 'TPE1',
TAL => 'TALB',
};
if( $has_ex_header )
{
my $ex_size = unpack("\@$offset N", $content);
if( !$ex_size || $ex_size <= 6 || $offset + $ex_size > length($content) )
{
return;
}
#my $ex = substr($content, $offset, $size);
$offset += $size;
}
# frames.
for(;;)
{
my ($id, $size, $flags);
my ($hsize, $hformat);
if( $major == 2 )
{
# 2.2.x
if( $offset + 6 > length($content) )
{
last;
}
($id, $size) = unpack("\@$offset a3 a3", $content);
$id = $old_frameid->{$id} || $id;
$size = unpack("N", "\0".$size);
$flags = 0;
$offset += 6;
}else
{
# 2.3.x-
if( $offset + 10 > length($content) )
{
last;
}
($id, $size, $flags) = unpack("\@$offset a4 N n", $content);
$offset += 10;
}
if( $offset + $size > length($content) )
{
# over flow.
last;
}
my $pack = substr($content, $offset, $size);
$offset += $size;
if( $id eq 'TIT2' )
{
$info->{title} = $pkg->_decode_text_normal($pack);
}
if( $id eq 'TPE1' )
{
$info->{artist} = $pkg->_decode_text_normal($pack);
}
if( $id eq 'TALB' )
{
$info->{album} = $pkg->_decode_text_normal($pack);
}
}
$info;
}
sub _decode_text_normal
{
my $pkg = shift;
my $pack = shift;
defined($pack) && length($pack)>=1 or die "#_decode_text_normal, no input";
my $type = unpack("C", substr($pack, 0, 1, ''));
my $out;
if( $type == 0 )
{
# local encoding.
$out = Unicode::Japanese->new($pack, 'auto')->utf8;
}elsif( $type == 1 )
{
# UTF-16 (with-BOM)
$out = Unicode::Japanese->new($pack, 'auto')->utf8;
}elsif( $type == 2 )
{
# UTF-16BE (without-BOM)
$out = Unicode::Japanese->new($pack, 'utf16be')->utf8;
}elsif( $type == 3 )
{
# UTF-8
$out = $pack;
}else
{
die "#_decode_text_normal, unsupported type: $type";
}
$out =~ s/\0+\z//;
$out;
}
# -----------------------------------------------------------------------------
# End of Module.
# -----------------------------------------------------------------------------
# -----------------------------------------------------------------------------
# End of File.
# -----------------------------------------------------------------------------
__END__
=encoding utf8
=for stopwords
YAMASHINA
Hio
ACKNOWLEDGEMENTS
AnnoCPAN
CPAN
RT
|
