[mythtv] XvMC VLD extension (beginnings of fix)

[Chad]

On 9/23/06, Michael Weber <mtweber at gmail.com> wrote:
> > > > I tried the mythtv-vid branch for Via SP13000 HDTV decoding and all I
> > > > get is a blank screen with good audio when trying to play 1080i
> > > > content.
>
> > Just an FYI:
> > Same thing is happening to me.  Blank screen, smooth audio with the
> > VID branch on 1080i content using very new SVN openchrome drivers on a
> > CN400 (SP13000 as well as Commell 667-T).  720p stutters far too much
> > to be watchable either, but I'm holding out, choosing which 'bugs' to
> > file, 1 bug-per-project at a time preferably ;)
>
> After some work trying to understand the code, I have a patch for
> 1080i playback on the CN400 (well at least for the SP13000).  I
> haven't attached the patch to the trac yet because all this patch does
> is get the video to display instead of the blue screen.  The display
> is good, but now the decoder can't to keep.  I have spent some time
> looking into this since xine can play 1080 pretty easily.
>
> I think the the problem may be with the communication with the
> openchrome driver.  In the driver, a mutex locks each call.  So while
> myth is placing the image with PutSurface, the decoder cannot access
> PutSlice because of the mutex.  Now, xine accomplishes it with the
> locks somehow, but I haven't figured out how yet.
>
> I already tried to move the SyncSurface from frame end to just before
> the PutSurface.  This reduces the number of buffering pauses for 1080i
> and eliminates them from 720p, but it creates other problems with
> ffw/rew and skipping.
>
> Another note about HD playback on CN400s, with 720p, even in xine
> (which doesn't not have the stuttering problem like myth), the video
> is shuffled (repeated blocks of lines on the left and right).  I have
> not started looking into this yet, but it seems like there is a
> problem with they way the slices get to the CN400 in both xine and
> myth.
>
> mike
>
>
> _______________________________________________

Haven't had a chance yet, but can you tell me where and how to apply
this patch?  I'm not home yet, but will be later this evening and
would like to roll it in to see the progress and give feedback.

Thanks!

-Chad