readme

mp3解码程序

amp MPEG audio decoder readme file (version 0.7.5)
(C) Tomislav Uzelac  1996,1997

amp is free software and can be _used_ freely by anyone. If you want to
do anything else with it, be sure to check the Legal section of this
document for legal issues.

THERE IS NO WARRANTY FOR THIS PROGRAM. Please check out the Legal section
of this document.

1. Introduction
2. Installation
3. Running
4. Feedback
5. Contributing
6. Legal


1. Introduction

amp (Audio Mpeg Player) is an MPEG audio decoder which I originally started 
putting together as a side project of the MPEG hardware design project at 
FER/Zagreb - just to confirm my knowledge of the standard. It works with
both MPEG1 and MPEG2 audio streams (except for the multichannel extensions
defined in MPEG2), layers 2 and 3. 

There is a gui for amp, written in Tcl/Tk by Edouard Lafargue. It is 
available at the amp home site ftp://ftp.rasip.fer.hr

Another gui supported is the Sajber Jukebox, written by Joel Lindholm.

The following people contributed their time and knowledge to amp:
Karl Anders Oygard, Ilkka Karvinen, Lutz Vieweg, Dan Nelson,
Edouard Lafargue, Andrew Richards, George Colouris,
Dmitry Boldyrev, Andy Lo A Foe, Thomas Sailer, Justin Frankel

amp home location is
	ftp://ftp.rasip.fer.hr/pub/mpeg/

and the mailing list: send 'HELP' in the body of the message to:
	[e-mail]

If you want to find out more about MPEG, best places to start are
	http://www.mpeg.org
	http://www.mpeg2.de 


2. Installation

Installation should be simple enough if amp was ported to your system,
just do a 

./configure
make 

You can edit the makefile further to suit your system. If configure fails 
to make a usable Makefile, you'll _have_ to edit it yourself.

Linux users should try real-time playing support, as described
in doc/realtime.txt. Some people that might pass on this feature are
those with slower machines (i.e. 486's), or SMP systems (see the
doc/linuxrealtime.txt file). 
Some versions of the linux C library produce an error when compiling
amp with realtime support. A quick fix is to edit /usr/include/sched.h
and replace _P in the offending line with __P.

./configure --enable-realtime
make
chown root.root amp
chmod u+s amp

... this requires /dev/dsp to be both world readable and writeable. If you
have a special group for people allowed to use the sound device (for
instance, a group called sound), you can do a:

chmod g+s amp

or make your audio card world read/writeable (not recomended)

chmod o+rw /dev/dsp*

3. Running:

'amp -h' gives you usage & options. If your computer is on the slower
side, direct playback might not work, but you can decode it
to .wav or raw pcm and play it later.


4. Feedback

Send in your makefiles, opinions, bugreports, fixes; anything related to this
program. You can also send me unlimited amounts of money, sugar, milk, etc.

If you find any mpeg audio files that amp has trouble decoding, please tell
me about this via e-mail <[e-mail]>.


5. Contributing

Please contribute to amp. If you want to know what is going on in amp 
development, you can join the developers mailing list

	[e-mail]

There are certain debugging facilities that I made in amp, but are disabled
in the current release (they are neither nice nor user-friendly). If anyone
enhances them (they are in dump.c) to the point that they're actually
usable I'll be happy to include the changes in the release. I think this
kind of debug output would be very useful to people studying these audio
algorithms.


6. Legal

This software can be used freely for any purpose. It can be distributed
freely, as long as it is not sold commercially without permission from
Tomislav Uzelac <[e-mail]>. However, including this software
on CD_ROMs containing other free software is explicitly permitted even 
when a modest distribution fee is charged for the CD, as long as this
software is not a primary selling argument for the CD.

Building derived versions of this software is permitted, as long as they
are not sold commercially without permission from Tomislav Uzelac 
<[e-mail]>. Any derived versions must be clearly marked as
such, and must be called by a name other than amp. Any derived versions
must retain this copyright notice.

/* This license is itself copied from Tatu Ylonen's ssh package. It does 
 * not mention being copyrighted itself :)
 */

THERE IS NO WARRANTY FOR THIS PROGRAM - whatsoever. You use it entirely
at your risk, and neither Tomislav Uzelac, nor FER will be liable for
any damages that might occur to your computer, software, etc. in
consequence of you using this freeware program.


Tomislav Uzelac
<[e-mail]>