MPEG 1 Layer 3 Audio encoder source?

MPEG 1 Layer 3 Audio encoder source?

Post by Frank M. Siege » Wed, 06 Mar 1996 04:00:00



Does anyone has seen the source for a MPEG 1 Layer 3 Audio encoder? I am aware of
the one done by the FhG but this is not available on the net as source code.

Have a nice day

        - Frank

---

NeXTSTEP, Linux & PostScript Guy              "In cantonese C++ is called C ga ga"

 
 
 

MPEG 1 Layer 3 Audio encoder source?

Post by Edouard Po » Sat, 09 Mar 1996 04:00:00



Quote:>Does anyone has seen the source for a MPEG 1 Layer 3 Audio encoder? I am
>aware of the one done by the FhG but this is not available on the net as
>source code.

The reference implementation was last time I looked. It's about 3 times
slower than the binary that FhG give out as shareware, but that's
easy to fix with the help of a profiler, some judicious inlining, and
the removal of the patently unnessessary code (like where it sets
up it's tables and 1/4 of the values are produced by multiplying the
input data by zero).

ftp://ftp.fhg.de/pub/layer3/public_c/mpeg1_iis.tar.gz from memory...

Quote:>Have a nice day

>    - Frank

Cheers,
Edouard.

 
 
 

MPEG 1 Layer 3 Audio encoder source?

Post by Frank M. Siege » Sat, 09 Mar 1996 04:00:00




> >Does anyone has seen the source for a MPEG 1 Layer 3 Audio encoder? I am
> >aware of the one done by the FhG but this is not available on the net as
> >source code.
> The reference implementation was last time I looked. It's about 3 times
> slower than the binary that FhG give out as shareware, but that's
> easy to fix with the help of a profiler, some judicious inlining, and
> the removal of the patently unnessessary code (like where it sets
> up it's tables and 1/4 of the values are produced by multiplying the
> input data by zero).
> ftp://ftp.fhg.de/pub/layer3/public_c/mpeg1_iis.tar.gz from memory...

Yes, it's there but unfortunately it seems to be only a decoder and I am searching for an
encoder.

From the readme:
 This directory contains the MPEG-1 public source code for the Audio decoder
 layer 1, 2 and 3 as per printing of CD 11172-5 in April 1994.

Have a nice day

        -Frank

---

NeXTSTEP & PostScript Guy              "In cantonese C++ is called C ga ga"

 
 
 

MPEG 1 Layer 3 Audio encoder source?

Post by Edouard Po » Mon, 11 Mar 1996 04:00:00





>> >Does anyone has seen the source for a MPEG 1 Layer 3 Audio encoder? I am
>> >aware of the one done by the FhG but this is not available on the net as
>> >source code.
>> The reference implementation was last time I looked. It's about 3 times
>> slower than the binary that FhG give out as shareware, but that's
>> easy to fix with the help of a profiler, some judicious inlining, and
>> the removal of the patently unnessessary code (like where it sets
>> up it's tables and 1/4 of the values are produced by multiplying the
>> input data by zero).
>> ftp://ftp.fhg.de/pub/layer3/public_c/mpeg1_iis.tar.gz from memory...
>Yes, it's there but unfortunately it seems to be only a decoder and I
>am searching for an encoder.

Mea culpa. I was getting FhG's binaries and sources mixed up - you're right
of course, the above path points only to the decoder.

Sorry for my mistake,
Edouard.

 
 
 

MPEG 1 Layer 3 Audio encoder source?

Post by Bodo Teichma » Wed, 13 Mar 1996 04:00:00




   >
   > >Does anyone has seen the source for a MPEG 1 Layer 3 Audio encoder? I am
   > >aware of the one done by the FhG but this is not available on the net as
   > >source code.
   >
   > The reference implementation was last time I looked.
   ...
   >
   > ftp://ftp.fhg.de/pub/layer3/public_c/mpeg1_iis.tar.gz from memory...

   A good memory, but not quite what the original poster asked for.

yes because this is the source code for the decoder layer1,2,3

   To my knowledge (and I'll gladly be updated) there is no "MPEG 1 Layer 3
   Audio encoder source" as per the original query.  As I understand it,
   MPEG only define the bitstream format and hence there is scope for
   proprietary implementations of encoding algorithms - hence no encoding
   source.

wrong, there is  a public C souce code for the encoder
ftp://ftp.tnt.uni-hannover.de/pub/MPEG/audio/mpeg2/public_software/te...

this tar contains the mpeg2 encoder and decoder with low sampling freq and
multichannel and *including* all  mpeg1 formats .
although the readme does not mention layer 3 there is a layer 3 lsf (and mpeg1!)
encoder  included !

   However, my reading of the various source codes that are around
   is that the intention is to release a noddy version (read "reference"
   version) of these codecs one day.

   Anybody in the know knows when that day will be?

this is the day...

bodo
--
/* Bodo Teichmann, Fraunhofer Institut Integrierte Schaltungen,

Tel.: +49 9131 776367                  Fax.: +49 9131 776399 */

 
 
 

MPEG 1 Layer 3 Audio encoder source?

Post by Tony Robins » Fri, 22 Mar 1996 04:00:00



> wrong, there is  a public C souce code for the encoder
> ftp://ftp.tnt.uni-hannover.de/pub/MPEG/audio/mpeg2/public_software/te...

> this tar contains the mpeg2 encoder and decoder with low sampling freq
> and multichannel and *including* all mpeg1 formats .  although the
> readme does not mention layer 3 there is a layer 3 lsf (and mpeg1!)
> encoder included !

Very nice to see a snapshot release of the current state of MPEG audio
reference.   As I said - I'm glad to be proved wrong.

Tony Robinson
SoftSound Ltd

 
 
 

MPEG 1 Layer 3 Audio encoder source?

Post by Bodo Teichma » Tue, 26 Mar 1996 04:00:00



>> wrong, there is  a public C souce code for the encoder
>> ftp://ftp.tnt.uni-hannover.de/pub/MPEG/audio/mpeg2/public_software/te...

>> this tar contains the mpeg2 encoder and decoder with low sampling freq
>> and multichannel and *including* all mpeg1 formats .  although the
>> readme does not mention layer 3 there is a layer 3 lsf (and mpeg1!)
>> encoder included !
>Very nice to see a snapshot release of the current state of MPEG audio
>reference.   As I said - I'm glad to be proved wrong.

just on thing to avoid missunderstandings: the quality of this public
C source is *not* "reference quality", but this encoder source is just
to get a valid bitstream at all and not to get a bitstream with good
sound quality or to get a fast encoder (this is true for all 3
layers).
moreover this source is *not* freeware or shareware, it is for
evaluation purposes only.

people who  are interested on comercial implementations (or realtime
hardware) of mpeg audio layer 3 , which have a realy good
soundquality, sould have a look at:

<http://www.iis.fhg.de/departs/amm/layer3/index.html>

bodo teichmann
--
/* Bodo Teichmann, Fraunhofer Institut Integrierte Schaltungen,

Tel.: +49 9131 776367                  Fax.: +49 9131 776399 */