Diagnosing Frame Sync Issues?

[Chuck Crisler]

How many USB connections are you using? While you *COULD* use a
multi-threaded decoder, that would probably only increase your frame-sync
problem and not give any significant benefit (though decoding a 4k
resolution frame would be quicker). If you forced a single thread decode
and multi thread display that might give you some insight into where the
problem is. It is a neat problem though!


On Mon, May 13, 2013 at 3:13 PM, Stirling Westrup <swestrup at gmail.com>wrote:

> This may, or may not, be a GStreamer issue. I've written a video-wall
> application that splits a playing video into pieces and shows the pieces on
> zero-clients connected to the host computer via USB or Ethernet cable.
>
> This basic functionality is working, but when playing large (ie 4K
> resolution) videos, we sometimes see momentary differences between when
> different monitors get updated with the next frame of video.
>
> Now, I can easily imagine a number of places that a video frame may be
> delayed so as to show after its neighbor:
>
> 1) Inside the GStreamer pipeline.
> 2) Inside the network stack
> 3) due to USB bandwidth issues.
>
> So far the only code in GStreamer that tries to maintain sync is that in
> the queue that handles each output monitor. The assumption made was that
> that would be sufficient. I could (with a lot of rewriting) replace all N
> output queues with a single N-way multiqueue, but I'm unsure that such a
> move is actually necessary.
>
> Does anyone have any suggestions of ways, techniques, whatever to try to
> narrow down cause of the frame sync issue before I go rewriting great
> chunks of code. I would hate to do all that just to find out it was a USB
> driver issue all along...
>
> --
> Stirling Westrup
> Programmer, Entrepreneur.
> https://www.linkedin.com/e/fpf/77228
> http://www.linkedin.com/in/swestrup
> http://technaut.livejournal.com
> http://sourceforge.net/users/stirlingwestrup
>
> _______________________________________________
> gstreamer-devel mailing list
> gstreamer-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/gstreamer-devel/attachments/20130513/4c1e56eb/attachment.html>