Monday, March 1, 1999 ***WARNING*** This module seems quite stable, and my tests (more extensive now) seem to work well, and the reports I've gotten are positive. There have been significant changes to the most important functions, which should improve performance and reliability. These should make the module better, but may in some cases make it worse for your MP3 files. If you are having problems with an MP3 file and this module, please contact me directly. I will likely ask you to put the MP3 file(s) in question in a place I can access them (HTTP or FTP), so I can test them directly (NOTE: this is not just a clever ploy to get you to send me MP3s :). I don't anticipate serious problems, and in fact I have not been able to find an MP3 file that the new module fails on. But you have been warned. ***WARNING*** This archive can always be obtained from: http://www.perl.com/CPAN/authors/id/CNANDOR/ http://www.perl.com/CPAN/modules/by-module/MPEG/ Mac users: The file is a tarred, gzipped file. Use Stuffit Expander or a similar program (like my cpan-mac stiuff) to get at the archive. Please let me know how well it does(n't) work, and any changes you'd like to see. Check out the script from Meng Weng Wong in eg/, it's pretty cool, and if you have the unreleased CDDB module, it will be even cooler. #============================================================================ 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, $HASHREF) Adds/changes tag information in an MP3 audio file. Will clobber any existing information in file. Fields are TITLE, ARTIST, ALBUM, YEAR, COMMENT, GENRE. All fields have a 30-byte limit, except for YEAR, which has a four-byte limit, and GENRE, which is one byte in the file. The GENRE passed in the function is a case-insensitive text string representing a genre found in `@mp3_genres'. Will accept either a list of values, or a hashref of the type returned by `get_mp3tag'. get_mp3tag (FILE) Returns hash reference containing tag information in MP3 file. Same info as described in `set_mp3tag'. get_mp3info (FILE) Returns hash reference containing file information for MP3 file. This data cannot be changed. TODO ID3v2 Support Added recognition of ID3v2 headers, speeding up `get_mp3info' for those files that have ID3v2 tags. Want to add functionality to get and set data in those tags. HISTORY v0.61, Monday, March 1, 1999 Fixed problem of not removing nulls on return from `get_mp3tag' (was using spaces for padding before ... now trailing whitespace and all nulls are removed before returning tag info). Made tests more extensive (more for my own sanity when making all these changes than to make sure it works on other platforms and machines :). v0.60, Sunday, February 28, 1999 Cleaned up a lot of stuff, added more comments, made `get_mp3info' much faster and much more reliable, and added recognition of ID3v2 headers. Thanks to Tom Brown for his help. v0.52, Sunday, February 21, 1999 Fixed problem in `get_mp3tag' that changed value of `$_' in caller (Todd Hanneken ). 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 ). 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 . 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 ). v0.03, Tuesday, September 8, 1998 First public release. AUTHOR AND COPYRIGHT Chris Nandor 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 #============================================================================