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

Robert McNamara robert.mcnamara at gmail.com
Fri Feb 5 17:23:43 UTC 2010

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.jpg
>> 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.


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