Re: [xine-devel] xine and hardware decoders

[Eduard H. <ed...@ao...>]

On Wed, Jul 11, 2001 at 05:20:38PM +0200, Matthias Hopf wrote:
> > > Well, as you said it sounds ugly, I just forget about it. Maybe someone
> > > finds out in future why the video and audio drifts so much.
> > 
> > yep, definitely
> 
> Why is easy. There are three different clocks in the system.
> The system clock, the video clock, and the audio clock.
> If you want your system to be synchronized perfectly, you have to use only one
> clock for timing. But unfortunately, this is not possible with PC hardware.
 
> The clocks are very simple Quarz clocks. They neither calibrated nor
> stabilized. Some of then can be off by 1/1000...

This would also be my first answer when I would have heard this. But
this is not the case.

Lets explain this:
The dxr3 card contains an processor called em8300. This processor is
responsible for both sending audio data and decompressing video
data. So, video and audio use in fact the same clock. Considering
this, I have still no idea why video and audio is drifting.

Unless there is some "hidden" oscillator on the card, there must
be something wrong with the linux driver. 

-- 
Eduard Hasenleithner
student of
Salzburg University of Applied Sciences and Technologies