Monday, March 6, 2000
Major update to this version is variable bitrate (VBR) support and a name change; it is now MP3::Info. A wrapper module is included so scripts calling MPEG::MP3Info will still work.
Included tests don't yet test ID3v2 or VBR support.
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 stuff, also in the CNANDOR directory) to get at the archive.
Please let me know how well it does(n't) work, and any changes you'd like to see. Thanks to all of the people who have sent me feedback and ideas. If something you want still remains unimplemented, let me know.
#============================================================================
NAME
MP3::Info - Manipulate / fetch info from MP3 audio files
SYNOPSIS
#!perl -w
use MP3::Info;
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 MP3::Info qw(:genres);
use MP3::Info qw(:DEFAULT :genres);
use MP3::Info 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 [, TRACKNUM]) 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'.
If TRACKNUM is present (for ID3v1.1), then the COMMENT field can
only be 28 bytes.
ID3v2 support will come eventually.
get_mp3tag (FILE [, VERSION, RAW_V2])
Returns hash reference containing tag information in MP3 file.
Same info as described in `set_mp3tag'.
If VERSION is `1', the information is taken from the ID3v1 tag (if
present). If VERSION is `2', the information is taken from the
ID3v2 tag (if present). If VERSION is not supplied, the ID3v1 tag
is read if present, and then, if present, the ID3v2 tag
information will override any existing ID3v1 tag info.
If the ID3v2 version is older than ID3v2.3.0, it will not be read
(and a warning will be issued if -w is on).
If RAW_V2 is false or not supplied and VERSION is `2', only the
tags corresponding to ID3v1 tags are returned, with the same keys
in the returned hashref.
If RAW_V2 is true and VERSION is `2', `get_mp3tag' will return a
hash of tag four-character IDs and their data. Tag IDs and their
meanings are in the global hash (not exported) `%v2_tag_names'.
my $tag = get_mp3tag('mysong.mp3', 2, 1); # ID3v2, raw ID3v2 tags
for (keys %$tag) {
printf "%s => %s\n", $MP3::Info::v2_tag_names{$_}, $tag->{$_};
}
get_mp3info (FILE)
Returns hash reference containing file information for MP3 file.
This data cannot be changed. Returned data includes MP3 version
(VERSION), total time in minutes (MM) and seconds (SS), boolean
for STEREO, MPEG layer (LAYER), BITRATE, MODE, boolean for
COPYRIGHT, and FREQUENCY.
Variable bitrates not yet supported. See the section on "TODO".
TROUBLESHOOTING
If you find a bug, please send me a patch. If you cannot figure out why it does not work for you, please put the MP3 file in a place where I can get it (preferably via FTP) and send me mail regarding where I can get the file, with a detailed description of the problem.
If I download the file, after debugging the problem I will not keep the MP3 file if it is not legal for me to have it. Just let me know if it is legal for me ot keep it or not.
TODO
ID3v2 Support
First go at adding support for reading ID3v2 tags. Still need to
do more, such as using Compress::Zlib to decompress compressed
tags. But until I see this in use more, I won't bother. I might
not be able to support Unicode at all, until Perl supports 16-bit
Unicode. If something does not work properly with reading, follow
the instructions above for troubleshooting.
Still need to add support for writing ID3v2 tags, and work on API
a bit.
HISTORY
v0.80, Monday, March 6, 2000
Better stripping of bad data (after nulls) in ID3 tags (Dave
O'Neill)
Fixed VERSION in get_mp3info to properly return 2 when
appropriate. (Bogdan Surdu)
Added VBR support. Average bitrate is returned as BITRATE, and
minutes and seconds (MM and SS) should be accurate. (Andy Waite
for pointer to MP3Ext)
Made time calculation better overall.
Made MP3 header validation routines more comprehensive. (Matthew
Sachs for pointer to xmms source)
Changed name to MP3::Info (with wrapper still named MP3::Info).
v0.71, Thursday, July 8, 1999
Several fixes to ID3v2 support unpack unsigned instead of signed,
don't bail out after 4096-byte offsets on long ID3v2 headers.
Thanks much to Matthew Sachs.
v0.70, Saturday, July 3, 1999
Added preliminary ID3v2 reading support in `get_mp3tag'. Thanks
much to Tom Brown.
v0.64, Thursday, July 1, 1999
Found bug in checking TRACKNUM parameter, used \d instead of \d+.
Only gives spurious warnings, doesn't affect anything else.
Cleaned up a bit, prepare for impending ID3v2 support.
NOTE: truncate() broken in some builds of ActivePerl (517, maybe
others). No changes to module to fix problem. (Brian Goodwin)
v0.63, Friday, April 30, 1999
Added ID3v1.1 support. (Trond Michelsen, Pass F. B. Travis)
Added 255 (\xFF) as default genre. (Andrew Phillips)
I think I fixed bug relating to spaces in ID3v2 headers. (Tom
Brown)
v0.62, Sunday, March 7, 1999
Doc updates.
Fix small unnoticable bug where ID3v2 offset is tag size plus 10,
not just tag size.
Not publickly released.
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. (Tom Brown)
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' (`$MP3::Info::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 offsets if set to true.
Thanks to Matthew Sachs for his input and fixes, and for mp3tools.
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 with his mpgtools. 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.
THANKS
Johann Lindvall, Meng Weng Wong <mengwong@pobox.com>, Predrag Supurovic <mpgtools@dv.co.yu>, Matthew Sachs <matthewg@zevils.com>, Peter Kovacs <kovacsp@egr.uri.edu>, Roland Steinbach <roland@supportsystem. com>, Todd Hanneken <thanneken@hds.harvard.edu>, Tom Brown <thecap@usa.net>, Andrew Phillips <asp@wasteland.org>, Trond Michelsen <mike@crusaders.no>, Pass F. B. Travis <pftravis@bellsouth.net>, Vittorio Bertola <v.bertola@vitaminic.com>, Brian Goodwin <brian@fuddmain.com>, Bogdan Surdu <tim@go.ro>, Andy Waite <andy@mailroute.com>, Chris Sidi <sidi@angband.org>, Luke Drumm <lukedrumm@mypad.com>, Dave O'Neill <dave@nexus.carleton.ca>, Edward Allen <allenej@c51844-a.spokn1.wa.home.com>.
AUTHOR AND COPYRIGHT
Chris Nandor <pudge@pobox.com>, http://pudge.net/
Copyright (c) 2000 Chris Nandor. All rights reserved. This program is free software; you can redistribute it and/or modify it under the terms of the Artistic License, distributed with Perl.
SEE ALSO
mp3tools
http://www.zevils.com/linux/mp3tools/
mpgtools
http://www.dv.co.yu/mp3list/mpgtools.htm
http://www.dv.co.yu/mp3list/mpeghdr.htm
mp3tool
http://www.dtek.chalmers.se/~d2linjo/mp3/mp3tool.html
ID3v2
Xing Variable Bitrate
http://www.xingtech.com/support/partner_developer/mp3/vbr_sdk/
MP3Ext
http://rupert.informatik.uni-stuttgart.de/~mutschml/MP3ext/
Xmms
VERSION
v0.80, Monday, March 6, 2000
#============================================================================