[maemo-developers] [maemo-developers] problem with gstreamer and dsppcm

[From: Reinhard Enders]

Zeeshan Ali wrote:
> Hi again!
> 
>> I'm new to gstreamer, so I assumed the production of dsppcmsrc is
>> somehow restricted and filesink is consuming what it gets. You're not
>> telling me there is some busy waiting or stuff like that.
> 
>   No! i didn't say there is a busy loop involved here.

 From the rate, channel etc. one can easily estimate the  amount of
bytes eaten and saved by the filesink. That's around 16000
bytes per second. Wavenc shouldn't be computationally expensive
(compared to lameenc or vorbisenc). So I'm sure cpu time is wasted
somewhere.

When checking with the gst-launch script, recording eats up around
- 8%, when recording to the mmc (which seems to be a far more
   reasonable value)
- 28%, when recording to the onboard flash file system

So it looks like the implicit (but probably rather futile) compression
of the file system eats up already around 20% of cpu time.

May be the reason for the strange behaviour of the C-Code lies somewhere
else: interaction between gtk and gst loops, or some other stupid error.
I'll check a bit more before submitting a bug report.


- Reinhard