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

Peter Laengert peter at rogers.com
Fri Feb 5 18:25:03 UTC 2010


-----Original Message-----
From: mythtv-users-bounces at mythtv.org
[mailto:mythtv-users-bounces at mythtv.org] On Behalf Of Robert McNamara
Sent: Friday, February 05, 2010 12:24 PM
To: Discussion about mythtv
Subject: Re: [mythtv-users] Myth 0.22 / VDPAU / Horizontal "noise/sparkles"

On Fri, Feb 5, 2010 at 9:16 AM, Adam Stylinski <kungfujesus06 at gmail.com>
wrote:
> I'm telling you it's digital noise.  Try a different cable that is shield
> better.  Don't go crazy with monsters, but monoprice has some well
shielded
> cables that do DVI to HDMI.  Locally may be your only option for this
> weekend, though.
>
> On Fri, Feb 5, 2010 at 12:14 PM, Blammo <blammo.doh at gmail.com> wrote:
>>
>> On Fri, Feb 5, 2010 at 8:27 AM, Adam Stylinski <kungfujesus06 at gmail.com>
>> wrote:
>> > I had similar issues with my 9600 GT and it used to freak me out.  I
>> > couldn't find anything consistent with my settings and why it was doing
>> > that.  Then I replaced my DVI to HDMI adapter to HDMI cable setup for a
>> > cable with built in DVI on one end and HDMI on the other.  This cable
>> > also
>> > had the luxury of a ferrite core on both ends.  It turns out the issue
>> > was
>> > digital interference.  The symptoms you describe also sound a lot like
>> > digital interference.
>>
>> I wish it was that easy.. I notice something new last night that
>> changes where I think the source of the issue is. (I tried updating my
>> TRAC ticket (#7571) but it appears closed.)
>>
>> With superbowl coming up, I REALLY wanted to get this fixed, so last
>> night I put a new Hardrive in my frontend last night, and installed
>> F12-64bit from scratch. 190.50 drivers, mythtv-suite from atrpms..
>> Still sparkles.... with VDPAU on, and only for HDHR/MPEG2 off-air
>> content.
>>
>> One thing NEW I noticed however, and this blew me away..... The
>> artifacting actually shows up with x11vnc as well, which tends to
>> remove things like video-drivers from the formula and point more
>> towards decoding...
>>
>> I uploaded a couple of  "VPDAU on/off" screenshots to my ticket:
>>
>> ON: http://svn.mythtv.org/trac/attachment/ticket/7571/vdpau-glitter-1.jpg
>> OFF:
>>
http://svn.mythtv.org/trac/attachment/ticket/7571/cpuplusplus-no-glitter-1.j
pg
>>
>> I welcome ANY ideas... this is driving my out of my mind.....

This is not a cable issue, the OP mentioned that it appears in a VNC
window as well.  He rightly concludes that this is a decoding issue.
VDPAU is *much* less tolerant to signal error than software decode,
and this is strongly indicated here.  I would try removing splits,
adding amplification when necessary, and retuning antenna aim where
applicable and seeing how that helps-- suspect one or all of the above
will fix the issue.

Robert
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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.




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