[gst-devel] Preroll?

[Thomas Vander Stichele]

On Thu, 2004-07-15 at 10:21, Martin Soto wrote:
> Hi!
> 
> Is there any write up, or examples, or whatever about the preroll
> mechanism that is being worked on now? It seems to me this may help fix
> the audio/video sync problems we still have, so I'd like to look into it
> in more detail.

Hi Martin,

One starting point is
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/directx9_c/directX/htm/dataflowinthefiltergraph.asp
where the explanation of how paused<->playing is handled (paused queues
up samples in every element) is basically the same as what we are
calling preroll at the moment.

I think you are right - this technique (as explained in other parts of
that DirectShow manual, which is a very good read) will solve our
audio/video sync issues better than the current system we have.  The
biggest challenge for audio/video sync in GStreamer right now to me
seems that PAUSED<->PLAYING is expensive, causing elements to go to
PLAYING at big enough time differences to screw up sync.

Let us know what you think if you look into it.

Thomas


Dave/Dina : future TV today ! - http://www.davedina.org/
<-*- thomas (dot) apestaart (dot) org -*->
And redemption will pour and crashes to the floor
And a million cold thoughts won't stop you feeling warm
Because the love that you bring conquers all these things
<-*- thomas (at) apestaart (dot) org -*->
URGent, best radio on the net - 24/7 ! - http://urgent.fm/