[gst-devel] libmpg123 decoder plugin

[Roland Poppenreiter]

Hello everybody,

I hope this is the right mailinglist for this anouncement.  I wrote
a mp3 decoder plugin with the mpg123 library. One reason is that
mpg123 has some processor optimization (SSE, MMX, 3DNow, ...) in it
and should be faster than the mad decoder. I used the mad decoder
plugin (gstmad.c) as template for my plugin - so they are quite
similar. I wanted to benchmark both decoders and compare the results
but I ran into several problems and I got a few questions: 

 - sometimes i get a short white noise sound when i start playing an
   mp3 file with my mpg123 decoder plugin.
 - short white noise sound appears after seeking as well.
 - is it possible that data comming from the filesrc is sometimes
   overlapping? 
 - seeking is not always working, also not with the mad decoder.
 - the mad decoder decodes mpg samples to audio/x-raw-int 32 Bit,
   but most extensions (SSE, MMX, ...) can just handle 16 Bit
   samples, therefore I would preferre 16 Bit audio/x-raw-int as
   output for my decoder. 

I wrote a small mediaplayer (described in the GStreamer Application
Development Manual) to test my plugin. The problems occur with my
mediaplayer and also with the gst-launch program.

Sourcecode can be found here: https://semsemilla.kastel.net/gst/

I would appreciate little help to solve my problems or any opinion
about this plugin.

-- Roland Poppenreiter