**********************************************************************
* MPEG 1.0/2.0 _AUDIO_ PLAYER, V0.59r-gpl                            * 
*                                                                    *
* (full?) MPEG 1.0/2.0, Layer 1,2 and 3 support                      *
**********************************************************************


This release of mpg123 is based on Michael Hipp's last stable release,
with Debian patch 0.59r-19 applied and code licence changed to GPL.

For a full list of contributors to the mpg123 project, please take
a look at the file 'AUTHORS'.


The mpg123 project's homepage is now at:

  http://mpg123.sourceforge.net/





------------------------------------------------------------------------

This version plays a layer3,112Kbit/s,J-Stereo stream on my AMD 5x86/133Mhz
with about 66% CPU load. (on the console, NO X11)
If your machine isn't fast enough you may try the downsampling
feature (--2to1 and --4to1 options) 
Playing in '--singlemix' (stero reduced to mono) also saves some
CPU cycles, though the whole code is optimized for 'full' stereo playing.

'Benchmarks': (+/- 2%)
----------------------
(AMD 486/133MHZ,ASUS SP3G,256KB cache,DIRTY-TAG installed,(BusLogic SCSI))
(Layer3, 112Kbit/s, Joint-Stereo stream (partially MS stereo, no I-stereo))
(Compiled with: -DI386_ASSEM -DREAL_IS_FLOAT -DLINUX -Wall -O2 -m486
   -fomit-frame-pointer -funroll-all-loops -finline-functions -ffast-math)

  full quality:     (stero)     66% (-> may work on 486DX4-100)
                    (singlemix) 38% (-> should work on 486DX2-66)
  2:1 downsampling: (stereo)    48%
                    (singlemix) 30% (-> should work on 486DX-50)

---------------------------------------------------------------------
Description:

This isn't a new player. It's a fully rewritten version originally based 
on the mpegaudio (FHG-version) package. The DCT algorithm in the
synthesis filter is a rewritten version of the DCT first seen in the maplay
package, which was written by Tobias Bading (bading@cs.tu-berlin.de). The 
rewrite was neccassary, because the GPL may not allow this copyright mix.
The mpegaudio package was written by various people from the MPEG/audio
software simulation group. The maplay is under GPL .. You can find the
original source code and the mpegaudio package on: ftp.tnt.uni-hannover.de.

Especially layer3.c common.c and mpg123.h is based on the dist10 package.
The code is fullly rewritten but I'm using sometimes the
same variable names or similar function names as in the
original package.

In the current layer3.c I'm using a DCT36 first seen in Jeff Tsay's 
(ctsay@pasteur.eecs.berkeley.edu) maplay 1.2+ package. His code is
under GPL .. I also tried the enhancement from Mikko Tommila. His
code is also in layer3.c (but it's disabled at the moment, because
it was slightly slower than the unrolled 9 point DCT (at least on 
_my_ system)). Theoretically it should be faster. You may try it on
your system.

The output can converted to different audio formats and
rates. Currently, only (very simple) audiosupport for
the most common computer systems. It's possible
to build a 'generic' version which needs an external
audio player for playing.

I have tested the program with a lot of teststreams, but it's very 
likely, that there are still a few bugs.

Playing MP3s coming with MIMEType "audio/x-mpegurl" 
---------------------------------------------------
For netscape navigator: 
Go: Preferencs->Navigator->Applications
 Click 'NEW' Button and fill in the form:
  Description: MP3 Playlist
  MIMEType:    audio/x-mpegurl
  suffix:      m3u
 Click the 'Application' button below and add a
  mpg123 -@ %s
 or maybe better
  xterm -e mpg123 -@ %s
 in the application field. Press OK. That's all.


NAS notes: (from Martin Denn)
-----------------------------
you may wanna play with the following defines: (from audio.c)
  NAS_SOUND_PORT_DURATION 
  NAS_SOUND_LOW_WATER_MARK
Change them to optimize the player for your environment. For slow
networks a proven config is:
#define NAS_SOUND_PORT_DURATION 10 /* seconds */
#define NAS_SOUND_LOW_WATER_MARK 75 /* percent */

Pentium optimization notes:
---------------------------
The ASM optimaztions are especially for Intel Pentium FPUs.
On other processorts the egcs compiler optimiazation
may do a better job.

3DNow notes:
------------
You need a new 'as'. ie. the 'as' from binutils-2.9.1.0.19a.
If you dont have a suitable as, you may wanna try to _copy_ the
files dct64_3dnow.o and decode_3dnow.o from the precompiled/ 
directory to the base mpg123 source path and try to compile
the source.
A funny side-effect of the 3dnow optimizations is, that now the
-2 and -4 downsampling is a little slower than full quality, because
the 3dnow optimization is only enabled for full quality decoding.
3dnow only works with -DREAL_IS_FLOAT. 


have fun,
           Mike

----------------------------------------------------------------------------

Just for info:
    I'm also working (but not at the moment) on a DSP port for this package. 
    A first testversion of the _LAYER-2_ part is finished and seems
    to work in realtime with my 20MHZ ADSP-2115 

----------------------------------------------------------------------------

Copyrights (c) 1995,1996,1997 of all changes/modifications and
of the new code by Michael Hipp. All rights reserved.
Copyrights (c) 1997 of several enhancements by Oliver Fromme.
See the packages 'maplay 1.2(+)' and 'mpegaudio' for their copy-policies.
Copyrights (c) 1997 of the OS2 specific parts by Niclas Lindstrom

known bugs:
-----------
  layer 3 i-stereo not heavily tested
   btw: I'm looking for i-stereo teststreams .. maybe you could send me a few
  Layer 1 not heavily tested
  no CRC checking ..
  no 'free format streams'
  no clean audio interface
  MPEG 2.0, Layer1 and Layer2 not tested (and probably will not work)
  MPEG 2.0, Layer3 not heavily tested .. may has bugs.

related information:
--------------------
  If you need an mp3 frame re(assembler) and stream debug tool you should
  have a look at the mp3asm program on Olli's mpg123 page.(http://mpg.123.org)

some interessting patent information:
-------------------------------------
  http://www.iis.fhg.de/amm/legal/

