[mythtv-users] Myth 0.22 / VDPAU / Horizontal "noise/sparkles"

[Frank Merrill]

On Fri, Feb 5, 2010 at 1:25 PM, Peter Laengert <peter at rogers.com> wrote:
>
> I think the OP is correct in blaming this on his onboard chipset.  A number
> of users have reported similar issues playing back MPEG2 video with VDPAU,
> and the chipset appears to be the common element:
>
> http://www.nvnews.net/vbulletin/showthread.php?t=136817&page=3
>
> In my case, the sparkles or artifacts began appearing when I upgraded my
> video card to a 9500GT.  I can largely eliminate the problem by playing the
> same recording using mplayer (with VDPAU) rather than mythtv's internal
> player.
>
> The good news is that NVIDIA has replicated the problem and is working on a
> fix.
>

I had to go back and search for the OP's first post about this, and
see what was tried, and had the same issues with both an 8500GT and a
9500GT.
Both of those cards only do VDPAU feature set A.
Feature set A is partial MPEG1 and 2 acceleration, but full H.264
acceleration. (and he indicates no issue with H.264)
On a related note, I don't see the same issue on a lowly 8400GS which
does Feature set B which is Full MPEG1 and 2 and H.264 acceleration.
(this is an 8400GS using the G98 GPU, not an 8400S using a G86 GPU)

One other thing is I wonder about the VDPAU buffers with the Internal
player and what they are set at.
It can be changed using a custom filter setting  of
'vdpaubuffersize=xx' where I would set that to at least 24, but I'm
not certain as to whether the VDPAU buffers are being set
automatically now by the VDPAU code in Myth.

I believe he reported that it did not show the symptom with same MPEG2
recordings played back in mplayer using VDPAU, and if I am not
mistaken, mplayer does set the VDPAU buffer sizes depending upon the
video codec (decoder) being used.

All speculation on my part, but if it's apples to apples, and mplayer
is using both vo=vdpau of vc=ffmpeg12vdpau without issues, then this
should also be able to be accomplished without blocking artifacts with
the internal player in Myth using the right configuration.

Frank