NAME
MPEG::MP3Play - Perl extension for playing back MPEG music
SYNOPSIS
use MPEG::MP3Play;
my $mp3 = new MPEG::MP3Play;
$mp3->open ("test.mp3");
$mp3->play;
$mp3->message_handler;
DESCRIPTION
This Perl module enables you to playback MPEG music.
This README and the documention cover version 0.15 of the MPEG::MP3Play
module.
PREREQUISITES
Xaudio SDK
MPEG::MP3Play is build against the 3.0.8 and 3.2.1 versions of the
Xaudio SDK and uses the async interface of the Xaudio library.
The SDK is not part of this distribution, so get and install it first
(http://www.xaudio.com/).
ATTENTION: Xaudio Version 3.2.x SUPPORT IS ACTUALLY BETA
Unfortunately Xaudio changed many internals of the API since version
3.0.0, and many of them are not documented. So I had to hack around, but
everything seem to work now. Even so I think 3.2.x support is actually
beta. If you have problems with this version, please send me an email
(see bug report section below) and downgrade to 3.0.x if you can't get
sleep ;)
For Linux Users:
Xaudio removed the 3.0.8 Linux version from their developer page. Please
read and agree to the license restrictions under
http://www.xaudio.com/developers/license.php and download the package
from here:
http://www.netcologne.de/~nc-joernre/-/xasdk-3.0.8.x86-unknown-linux-glibc.tar.gz
Perl
I built and tested this module using Perl 5.6.1, Perl 5.005_03, Perl
5.004_04. It should work also with Perl 5.004_05 and Perl 5.6.0, but I
did not test this. If someone builds MPEG::MP3Play successfully with
other versions of Perl, please drop me a note.
Optionally used Perl modules
samples/play.pl uses Term::ReadKey if it's installed.
samples/handler.pl requires Term::ReadKey.
samples/gtk*.pl require Gtk.
DOWNLOADING
You can download MPEG::MP3Play from any CPAN mirror. You will find it in
the following directories:
http://www.perl.com/CPAN/modules/by-module/MPEG/
http://www.perl.com/CPAN/modules/by-authors/id/J/JR/JRED/
You'll also find recent information and download links on my homepage:
http://www.netcologne.de/~nc-joernre/
INSTALLATION
First, generate the Makefile:
perl Makefile.PL
You will be prompted for the location of the Xaudio SDK. The directory
must contain the include and lib subdirectories, where the Xaudio header
and library files are installed.
make
make test
cp /a/sample/mp3/file.mp3 test.mp3
./runsample play.pl
./runsample handler.pl
./runsample gtk.pl
./runsample gtkhandler.pl
./runsample gtkinherit.pl
./runsample synopsis.pl
make install
SAMPLE SCRIPTS
There are some small test scripts in the samples directory. You can run
these scripts before 'make install' with the runsample script (or
directly with 'perl', after running 'make install'). For runsample
usage: see above.
All scripts expect a mp3 file 'test.mp3' in the actual directory.
play.pl Textmodus playback. Displays the timecode. Simple volume control
with '+' and '-' keys.
handler.pl
Does nearly the same as play.pl, but uses the builtin message
handler. You'll see, that this solution is much more elegant. It
*requires* Term::ReadKey.
This script makes use of the debugging facility, the equalizer
features and is best documented so far.
gtk.pl This script demonstrates the usage of MPEG::MP3Play with the Gtk
module. It produces a simple window with a progress bar while
playing back the test.mp3 file.
gtkhandler.pl
This script does the same as gtk.pl but uses the builtin message
handler concept instead of implementing message handling by
itself. Advantage of using the builtin message handler: no
global variables are necessary anymore.
Because 'runsample' uses '"perl -w"' you'll get a warning
message here complaining about a subroutine redefinition. See
the section USING THE BUILTIN MESSAGE HANDLER for a discussion
about this.
gtkinherit.pl
This is 'gtkhandler.pl' but throwing no warnings, because it
uses subclassing for implementing messages handlers.
synopsis.pl
Just proving it ;)
BASIC CONCEPT
The concept of the Xaudio async API is based on forking an extra process
(or thread) for the MPEG decoding and playing. The parent process
controls this process by sending and recieving messages. This message
passing is asynchronous.
This module interface provides methods for sending common messages to
the MPEG process, eg. play, pause, stop. Also it implements a message
handler to process the messages sent back. Eg. every message sent to the
subprocess will be acknowledged by sending back an XA_MSG_NOTIFY_ACK
message (or XA_MSG_NOTIFY_NACK on error). Error handling must be set up
by handling this messages.
You will find detailed information about the interface of
this module in its POD documentation.
TODO
- Win32 support
- support of the full Xaudio API, with input/output
modules, etc.
- documentation: more details about the messages
hashes
Ideas, code and any help are very appreciated.
BUGS
- treble control through the equalizer is weak. I checked
the sent data several times and cannot see any error
on my side, maybe something with my sound setup is strange,
or my ears are just broken :)
Please tell me, if the treble control is OK for you, or not.
PROBLEMS AND REPORTING BUGS
First check if you're using the most recent version of this module,
maybe the bug you're about to report is already fixed. Also please read
the documentation entirely.
If you find a bug please send me a report. I will fix this as soon as
possible. You'll make my life easier if you provide the following
information along with your bugreport:
- your OS and Perl version (please send me the output
of 'perl -V')
- exact version number of the Xaudio development kit
you're using (including libc version, if this is relevant
for your OS, e.g. Linux)
- for bug reports regarding the GTK+ functionality
I need the version number of your GTK+ library and
the version number of your Perl Gtk module.
If you have a solution to fix the bug you're welcome to send me a
unified context diff of your changes, so I can apply them to the trunk.
You'll get a credit in the Changes file.
If you have problems with your soundsystem (you hear nothing, or the
sound is chopped up) please try to compile the sample programs that are
part of the Xaudio development kit. Do they work properly? If not, this
is most likely a problem of your sound configuration and not a
MPEG::MP3Play issue. Please check the Xaudio documentation in this case,
before contacting me. Thanks.
MPEG::MP3Play APPLICATIONS
I'm very interested to know, if someone write applications based on
MPEG::MP3Play. So don't hesitate to send me an email, if you like (or
not like ;) this module.
TESTED ENVIRONMENTS
This section lists the environments where users reported me that this
module functions well:
- Perl 5.005_03 and Perl 5.004_04, Linux 2.0.33 and
Linux 2.2.10, Xaudio SDK 3.01 glibc6,
gtk+ 1.2.3, Perl Gtk 0.5121
- FreeBSD 3.2 and 3.3. See README.FreeBSD for details
about building MPEG::MP3Play for this platform.
- Irix 6.x, Perl built with -n32
AUTHOR
Joern Reder <joern@zyn.de>
COPYRIGHT
Copyright (C) 1999-2001 by Joern Reder, All Rights Reserved.
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
The Xaudio SDK is copyright by MpegTV,LLC. Please refer to the LICENSE
text published on http://www.xaudio.com/.
SEE ALSO
perl(1).
CHANGES
$Id: Changes,v 1.29 2008/03/30 10:26:42 joern Exp $
Revision history for Perl extension MPEG::MP3Play.
0.16 Sun Mar 30 2008, joern
- added patch from Yi Ma Mao for Makefile.PL so it conforms
to CPAN automated testing.
0.15 Fri Nov 02 2001, joern
- removed debugging code from equalizer
- added set_input_position_range submitted by
Tom House <ixo@one11.net>. Thanks for that, Tom.
0.14. Fri Jan 05 2001, joern
- puh, many changes of internal data structures in the 3.2.x
release of Xaudio. Some messages constants were gone, but
I didn't use them anywhere, so this should be no problem.
This version builds well with Xaudio 3.0.8 and 3.2.1 under
my Linux system.
0.13 Fri Jan 05 2001, joern
- added hint about incompatibility to actual Xaudio
releases 3.2.x. Hopefully the Xaudio guys document their
internal changes soon, so I can adjust MPEG::MP3Play...
0.12 Fri Sep 29 2000, joern
- Due to a bug in the Irix version of the Xaudio SDK the
Makfile.PL needs to determine Irix. -laudio is added in
this case. This version is only a bugfix release for
Irix systems, all other users need not to update.
0.11 Thu Sep 28 2000, joern
- actual Xaudio releases lacks the control_message_s?print
functions, so loading the .so module fails. Thanks to
Valery Sherman <sher@moscow.sgi.com> and Gryn <gryn@spinlock.org>
for the bug reports. Because these functions were not
documented in the MPEG::MP3Play documentation, I disabled
the corresponding code for a quick workaround, while reporting
this as a bug to Xaudio. Stay tuned, maybe a new bugfix release
is coming soon.
0.10 Sat Oct 09 1999, joern
- Equalizer support added, the samples/handler script
demonstrates the usage of the equalizer features.
The new methods are:
$mp3->equalizer ( [$left_lref, $right_lref] )
$mp3->get_equalizer
- Some news: Bryan Collins <bryan@casper.spirit.net.au> develops
a car audio MP3 player system, based on MPEG::MP3Play.
See his website for details: http://bry.spirit.net.au/mcoupe/
0.09 Fri Sep 26 1999, joern
- The error messages thrown on exit of the Gtk+ sample
scripts are gone. Thanks to Dermot Musgrove for his
suggestions. I added a small chapter about preventing
these error messages in the documentation.
- 'runsample' now uses 'perl -w'. MPEG::MP3Play and
all sample scripts should now work without throwing
warning messages (except 'gtkhandler.pl' where this
is intended).
- There is a new sample script 'gtkinherit.pl' to demonstrate
implementing message handlers by subclassing MPEG::MP3Play
- README.FreeBSD added, thanks go to Bryan Collins
<bryan@casper.spirit.net.au> for his detailed information.
- 'runsample' is now generated by Makefile.PL to ensure that
the correct Perl interpreter is used
0.08 Tue Sep 21 1999, joern
- Bugfix: MP3Play.xs did not compile with Perl 5.004_04, thanks
to Dermot Musgrove <dermot@glade.perl.connectfree.co.uk>
for his bug report. Now MPEG::MP3Play should work with all
Perl versions better or equal than 5.004_04.
Testers are welcome.
- added a section about REPORTING BUGS in the documentation
to make my life easier ;)
0.07 Wed Sep 08 1999, joern
- Bugfix: $mp3->get_message was broken in Version 0.06,
among other things the gtk* samples suffered from this
bug and did not function
- the creation of the message hash in MP3Play.xs and
conv_msg.c is now much more elegant. Thanks to
Dan Sugalski <dan@tuatha.sidhe.org> for the hint.
0.06 Mon Sep 06 1999, joern
- fixed a memory leak in the get_message* methods.
Thanks to Gene Senyszyn <scatt@goes.com> for the
detailed bug report
0.05 Mon Aug 09 1999, joern
- debugging implemented by providing default handlers
for XA_MSG_NOTIFY_ACK and _NACK.
- samples/handler.pl uses debugging for demonstration
purposes
0.04 Sat Aug 07 1999, joern
- implemented a builtin message handler mechanism.
Message corresponding methods will be invoked,
so the user can simply supply/overload the message
methods.
- added samples/handler.pl and samples/gtkhandler.pl
to demonstrate the use of the builtin message handler.
- added samples/synopsis.pl. This proves that the
usage shown in the SYNOPSIS really works ;)
- no symbols are exported by default anymore, some
Exporter tags are available instead.
THIS IS AN INCOMPATIBLE CHANGE.
Try 'use MPEG::MP3Play qw(:DEFAULT)' as a first step,
but better look into the documentation and see, which
symbols you really need to import.
I think 'use MPEG::MP3Play qw(:msg :state)' will work
in most cases.
- notification_mask setting
- player mode setting
- default message handler for player_state messages
- fixed some minor documentation typos
0.03 Thu Aug 05 1999, joern
- gen_constant generates constants.h included by
MP3Play.xs. gen_constant checks defines and enums,
not only defines like h2xs does.
- so now all Xaudio symbols are available
- gen* scripts moved to the tools directory
- test.pl now only loads the module
- there are now more sophisticated test scripts in
the samples directory, e.g. a script which uses
Gtk+ to play a file showing a progress bar. This
demonstrates the connection of the Xaudio
message queue to Gdk.
- almost anything well documented now
0.02 Tue Aug 03 1999, joern
- added gen_conv_msg.pl to generate conv_msg.c out
of the HTML documention provided by Xaudio
- conv_msg.c converts XA messages to HVs, for simple
handling in Perl
- test.pl enhanced. Now shows timecode and exits on
key pressure (if Term::ReadKey is installed) and
on end of file.
- fixed minor POD formatting errors in MP3Play.pm
0.01 Sun Jul 25 1999, joern
- original version; created by h2xs 1.19
- my first contact with XS, but playing mp3 files works
after two hours. I like it! ;)
- no error/message handling at all