MPEG Layer 3 audio: Public c source?

MPEG Layer 3 audio: Public c source?

Post by Hanno Muell » Thu, 19 Jan 1995 22:53:30



Hello everybody out there,

this was a letter I tried to e-mail to an address given in the
public c source of the new MPEG layer 3 audio decoder, as it
can be found on the ftp server ftp.tnt.uni-hannover.de in
/pub/MPEG/audio/FhG-IIS-l3share/public_c. But the address
appears to be invalid... Maybe someone of you can help me
with those questions:

   ----- Transcript of session follows -----

mail11: Error from DECnet MAIL object on node "3d",
        during mail delivery to <3D::PAN>.
        Remote error code is 0x7e8112, message is:
%MAIL-E-NOSUCHUSR, no such user PAN at node 3D

   ----- Recipients of this delivery -----
Bounced, cannot deliver:

   ----- Unsent message follows -----

Dear Mr. Pan,

I have tested the c source code of an MPEG-audio decoder that
is distributed by Fraunhofer - IIS, and it works just fine.

Nevertheless, the "readme" files says:

Quote:> As you can read in the source files work on these files is still in
> progress and they have not officially been released for public distribution.
> Nevertheless we at Fraunhofer Institute have tested the layer 3 part of
> the Decoder and believe that it is reasonably bug free.
> So feel free to evaluate the source code but keep in mind, that no
> warranties are associated with this software.

And the first lines of the file "decode.c" are:

> /**********************************************************************
> Copyright (c) 1991 MPEG/audio software simulation group, All Rights Reserved
> decode.c
> **********************************************************************/
> /**********************************************************************
>  * MPEG/audio coding/decoding software, work in progress              *
>  *   NOT for public distribution until verified and approved by the   *
>  *   MPEG/audio committee.  For further information, please contact   *


This is the reason why I am writing you. I have a few questions
concerning these c sources.

I have tested MPEG layer 3 audio compression during the last days and
I was more than amazed by the superiour quality of the results. I
have used the encoder of Fraunhofer IIS on a cappella music. While the
layer 2 encoder did not create good results at 1:7, listening tests on
layer 3 compressed a cappella music resulted in surprise - I could not
believe my ears (at 1:11!).

Some fellow students and I want to use the c sources of the decoder
to support spreading the MPEG layer 3 audio coding method. We want
to port the program to various (home) computer systems, e.g. IBM,
Amiga, Macintosh, Archimedes etc. We want to make sure to create
"foolproof" software that almost anyone can use to decode mpeg
audio files. We want to use the Fraunhofer encoder and the public
decoder to "publish" music of local amateur bands on our ftp server.

Enough blabla, here are the questions:

- Are we allowed to use those c sources now?

- If not, when will they be approved by the committee?

- Is it illegal to use the public c sources to create
  a public domain or shareware decoding software?

I hope that you can help me.

Thanks in advance,

Hanno Mueller

student
computer science department
universitaet hamburg
germany

(ah yes - Tenor of "Sechs Richtige", an a cappella sextett :-) )