[maemo-developers] [maemo-developers] gstreamer launcher (proper video sink?)

From: Frantisek Dufka dufkaf at seznam.cz
Date: Wed Apr 26 14:40:00 EEST 2006
Pinghang.Koon at tietoenator.com wrote:
> 
> Both of them works! : )
> 
That's cool :)

> Question:
> 
> 1)        Is it correct for me to use the dspfbsink directly?  (Frame 
> buffer)  Any pre-processing necessary?

I'd guess it isn't, but don't know. You would be missing the new window 
so it looks like there should be other way.

> 
> 2)        The w.mpg plays correctly on the bundled 770 movie player, but 
> pretty slowly with a lot of frame skips.  Is the CPU of Nokia 770 fast 
> enough to handle more advanced codecs, like xvid?

All the decoding is done by the DSP. This is IMO bad design choice for 
(advanced) video. DSP is simply overused and too slow for this. When 
playing the ice age trailer you can notice with load applet that CPU 
sits almost idle while DSP is struggling to decode everything. This 
makes sense for backgroung sound playback, but not for video. You hardly 
play video on the background :-)

It would be interesting to hook in mp4 gstreamer plugin that decodes 
video by the main CPU. This could result in much higher framerates or 
better resolution and better utilization of both main CPU and DSP. Or is 
there some catch why doing it on DSP makes better sense? AFAIK the main 
ARM CPU should be better suited for the task than the DSP.

BTW How much dedicated video memory is there? Can the video driver do 
double buffering directly in video memory? This would be useful for 
video playback too.

Frantisek

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