NAME

MPEG::MP3Info - Manipulate / fetch info from MP3 audio files

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

use_winamp_genres()

Puts WinAmp genres into @mp3_genres and %mp3_genres.

You can import the data structures with one of:

use MPEG::MP3Info qw(:genres);
use MPEG::MP3Info qw(:DEFAULT :genres);
use MPEG::MP3Info qw(:all);

remove_mp3tag (FILE)

Removes last 128 bytes from file if those last 128 bytes begin with the text `TAG'. File will be 128 bytes shorter. Returns undef if no existing TAG found, 1 on successful removal of TAG.

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.

Fields are TITLE, ARTIST, ALBUM, YEAR, COMMENT, GENRE. All fields have a 30-byte limit, except for YEAR, which has a four-byte limit, and GENRE, which is one byte in the file. The GENRE passed in the function 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.

get_mp3info (FILE)

Returns hash reference containing file information for MP3 file. This data cannot be changed.

TODO

ID3v2 Support

Added recognition of ID3v2 headers, speeding up get_mp3info for those files that have ID3v2 tags. Want to add functionality to get and set data in those tags.

HISTORY

v0.61, Monday, March 1, 1999

Fixed problem of not removing nulls on return from get_mp3tag (was using spaces for padding before ... now trailing whitespace and all nulls are removed before returning tag info).

Made tests more extensive (more for my own sanity when making all these changes than to make sure it works on other platforms and machines :).

v0.60, Sunday, February 28, 1999

Cleaned up a lot of stuff, added more comments, made get_mp3info much faster and much more reliable, and added recognition of ID3v2 headers. Thanks to Tom Brown <thecap@usa.net> for his help.

v0.52, Sunday, February 21, 1999

Fixed problem in get_mp3tag that changed value of $_ in caller (Todd Hanneken <thanneken@hds.harvard.edu>).

v0.51, Saturday, February 20, 1999

Fixed problem with %winamp_genres having the wrong numbers (Matthew Sachs).

v0.50, Friday, February 19, 1999

Added remove_mp3tag. Addeed VERSION to the hash returned by get_mp3info, and fixed a bug where STEREO was not being set correctly.

Export all genre data structures on request. Added use_winamp_genres to use WinAmp genres (Roland Steinbach <roland@support-system.com>).

Added a $MPEG::MP3Info::try_harder variable that will try harder to find the MP3 header in a file. False by default. Can take a long time to fail, but should find most headers at any offets if set to true.

Thanks to Matthew Sachs for his input and fixes.

mailto:matthewg@interport.net
http://www.zevils.com/linux/mp3tools/

Thanks also to Peter Kovacs <kovacsp@egr.uri.edu>.

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:

mailto:mpgtools@dv.co.yu
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) 1999 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

v0.61, Monday, March 1, 1999