NAME

MPEG::MP3Info - Manipulate / fetch v1 TAG and header info from a MP3 audio file

SYNOPSIS

#!perl -w
use MPEG::MP3Info;
my $file = 'Pearls_Before_Swine.mp3';
set_mp3tag($file, 'Pearls Before Swine', q"77's",
  'Sticks and Stones', '1990', q"(c) 1990 77's LTD.", 'rock & roll');

my $tag = get_mp3tag($file) or die "No TAG info";
$tag->{GENRE} = 'rock';
set_mp3tag($file, $tag);

my $info = get_mp3info($file);
printf "$file length is %d:%d", $info->{MM}, $info->{SS};

DESCRIPTION

set_mp3tag (FILE, TITLE, ARTIST, ALBUM, YEAR, COMMENT, GENRE)

set_mp3tag (FILE, $HASHREF)

Adds/changes tag information in an MP3 audio file. Will clobber any existing information in file. All fields have a 30-byte limit, except for YEAR, which has a four-byte limit.

GENRE is a case-insensitive text string representing a genre found in @mp3_genres.

Will accept either a list of values, or a hashref of the type returned by get_mp3tag.

get_mp3tag (FILE)

Returns hash reference containing tag information in MP3 file. Same info as described in set_mp3tag. You can't change this data.

get_mp3info (FILE)

Returns hash reference containing file information for MP3 file.

HISTORY

v0.20, Saturday, October 17, 1998

Changed name from MPEG::MP3Tag to MPEG::MP3Info, because it does more than just TAG stuff now.

Made header stuff even more reliable. Lots of help and testing from Meng Weng Wong again. :-)

v0.13, Thursday, October 8, 1998

Had some problems with header verification, got some code from Predrag Supurovic:

E<lt>mpgtools@dv.co.yuE<gt>
http://www.dv.co.yu/mp3list/mpgtools.htm
http://www.dv.co.yu/mp3list/mpeghdr.htm

Great stuff. Also did some looping to find a header if it is not in the "right" place. I did what I think it is a smart way to do it, since some files have the header as far down as 2 kbytes into the file. First, I look at position 0, then at position 36 (a position where I have found many headers), then I start at 0 again and jump in 128-byte chunks. Once I do that a bunch of times, I go back at the beginning and try at 0 and go ahead in 1-byte chunks for a bunch more times.

If you have an MP3 that has the header begin at an odd place like byte 761, then I suggest you strip out the junk before the header begins. :-)

v0.12, Friday, October 2, 1998

Added get_mp3info. Thanks again to mp3tool source from Johann Lindvall, because I basically stole it straight (after converting it from C to Perl, of course).

I did everything I could to find the header info, but if anyone has valid MP3 files that are not recognized, or has suggestions for improvement of the algorithms, let me know.

v0.04, Tuesday, September 29, 1998

Changed a few things, replaced a regex with an unpack (Meng Weng Wong <mengwong@pobox.com>).

v0.03, Tuesday, September 8, 1998

First public release.

AUTHOR AND COPYRIGHT

Chris Nandor <pudge@pobox.com> http://pudge.net/

Copyright (c) 1998 Chris Nandor. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. Please see the Perl Artistic License.

Thanks to Johann Lindvall for his mp3tool program:

http://www.dtek.chalmers.se/~d2linjo/mp3/mp3tool.html

Helped me figure it all out.

VERSION

v0.20, Saturday, October 17, 1998