[pulseaudio-discuss] GSoC: Call for project ideas

[Arun Raghavan]

On Mon, 2013-03-25 at 18:09 +0200, Tanu Kaskinen wrote:
[...] 
> > The simplest idea I can think of to deal with this meaningfully is to
> > wrap a sink/source around a GStreamer pipeline to offload all that work
> > that we don't want to duplicate in PulseAudio .
> > 
> > On the sink side, we'd hook up to an appsrc to feed PCM data to a
> > pipeline. The pipeline would take care of encoding, RTP packetisation
> > and possibly a corresponding RTCP stream. This would allow codec
> > selection to be flexible, and in the distant future, could even support
> > taking encoded data directly.
> > 
> > On the source side, we'd hook up to an appsink, receiving PCM data from
> > the pipeline. The pipeline would take care decoding whatever the format
> > is, take care of RTCP and maybe more advanced features such as a jitter
> > buffer and packet-loss concealment (all of this can be plugged in or
> > not, depending on configuration).
> > 
> > Doing it this way means you're using a better RTP stack that gets
> > attention from a number of other use cases (plus assorted related
> > goodies) and support for multiple codecs.
> > 
> > Thoughts?
> 
> I like the idea of offloading stuff to GStreamer very much.
> 
> Do you follow GStreamer development closely? If I've understood

Not very closely, but I do some periodically work on stuff in GStreamer
(and have commit access).

> correctly, GStreamer hasn't supported rewinding in the past, has there
> been any talk about that lately? Lack of rewinding support in any part
> of the audio pipeline causes bigger or smaller problems. I don't think
> it's a critical problem in this particular case, although rewind support
> would be useful in this case too. If we would like to use GStreamer for
> implementing filters, rewind support would be pretty mandatory.

The idea I have is separate from filters - it's really only about being
able to use GStreamer for codecs + networking (RTP).

I think the filtering system would have to be independently done - not
the least of which is because of what you pointed out - GStreamer does
not support rewinding.

-- Arun