NAME

MP4::Info - Fetch info from MPEG-4 files (.mp4, .m4a, .m4p)

SYNOPSIS

#!perl -w
use MP4::Info;
my $file = 'Pearls_Before_Swine.m4a';

my $tag = get_mp4tag($file) or die "No TAG info";
printf "$file is a %s track\n", $tag->{GENRE};

my $info = get_mp4info($file);
printf "$file length is %d:%d\n", $info->{MM}, $info->{SS};

my $mp4 = new MP4::Info $file;
printf "$file length is %s, title is %s\n",
	$mp4->time, $mp4->title;

DESCRIPTION

The MP4::Info module can be used to extract tag and meta information from MPEG-4 files audio (AAC) and video files. It is designed as a drop-in replacement for MP3::Info.

Note that this module does not allow you to update the information in MPEG-4 files.

$mp4 = MP4::Info->new(FILE)

OOP interface to the rest of the module. The same keys available via get_mp4info and get_mp4tag are available via the returned object (using upper case or lower case; but note that all-caps 'VERSION' will return the module version, not the MPEG-4 version).

Passing a value to one of the methods will not set the value for that tag in the MPEG-4 file.

use_mp4_utf8([STATUS])

Tells MP4::Info whether to return TAG info in UTF-8 or Latin-1. 1 is UTF-8, 0 is Latin-1. Default is Latin-1.

Function returns new status (1/0). If no argument is supplied, or an unaccepted argument is supplied, function merely returns existing status.

This function is not exported by default, but may be exported with the :utf8 or :all export tag.

get_mp4tag (FILE)

Returns hash reference containing the tag information from the MP4 file. The following keys may be defined:

ALB	Album
APID	Apple Store ID
ART	Artist
CMT	Comment
CPIL	Compilation (boolean)
CPRT	Copyright statement
DAY	Year
DISK	Disk number (2 integers)
GNRE	Genre
GRP	Grouping
NAM	Title
RTNG	Rating (integer)
TMPO	Tempo (integer)
TOO	Encoder
TRKN	Track number (2 integers)
WRT	Composer

Any and all of these keys may be undefined if the corresponding information is missing from the MPEG-4 file.

For compatibility with MP3::Info, the mp3 ID3v1-style tags TITLE, ARTIST, ALBUM, YEAR, COMMENT, GENRE and TRACKNUM are created as synonyms for NAM, ART, ALB, DAY, CMT, GNRE and TRKN[0].

Strings returned will be converted to Latin-1, unless UTF-8 is specified using use_mp4_utf8.

On error, returns nothing and sets $@.

get_mp4info (FILE)

Returns hash reference containing file information from the MPEG-4 file. The following keys may be defined:

VERSION		MPEG version (=4)
LAYER		MPEG layer description (=1 for compatibility with MP3::Info)
BITRATE		bitrate in kbps (average for VBR files)
FREQUENCY	frequency in kHz
SIZE		bytes in audio stream

SECS		total seconds
MM		minutes
SS		leftover seconds
MS		leftover milliseconds
TIME		time in MM:SS

COPYRIGHT	boolean for audio is copyrighted

Any and all of these keys may be undefined if the corresponding information is missing from the MPEG-4 file.

On error, returns nothing and sets $@.

BUGS

Doesn't support writing tag information to MPEG-4 files.

The calculation of bitrate is not very accurate, and tends to be under the real bitrate.

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 MP4 file in a place where I can get it (preferably via FTP, or HTTP) and send me mail regarding where I can get the file, with a detailed description of the problem. I will keep a copy of the file only for as long as necessary to debug the problem.

AUTHOR

Jonathan Harris <jhar@cpan.org>.

THANKS

Chris Nandor <pudge@pobox.com> for writing MP3::Info

SEE ALSO

MP4::Info Project Page

http://search.cpan.org/~jhar/MP4-Info

ISO 14496-12:2004 - Coding of audio-visual objects - Part 12: ISO base media file format

http://www.iso.ch/iso/en/ittf/PubliclyAvailableStandards/c038539_ISO_IEC_14496-12_2004(E).zip

ISO 14496-14:2003 - Coding of audio-visual objects - Part 14: MP4 file format

http://www.iso.org/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=38538 (Not worth buying - the interesting stuff is in Part 12).

QuickTime File Format

http://developer.apple.com/documentation/QuickTime/QTFF/

ISO 14496-1 Media Format

http://www.geocities.com/xhelmboyx/quicktime/formats/mp4-layout.txt

MP3::Info

http://search.cpan.org/~cnandor/MP3-Info/

COPYRIGHT and LICENSE

Copyright (c) 2004, Jonathan Harris <jhar@cpan.org>

This program is free software; you can redistribute it and/or modify it under the the same terms as Perl itself.