[mythtv-users] Video quality?

Yeechang Lee ylee at pobox.com
Mon Oct 1 00:56:35 UTC 2007

Michael T. Dean <mtdean at thirdcontact.com> says:
> OP: You are using OpenGL vsync ("for smooth delivery of frames"),
> right?  You do have it and the NVIDIA-provided vsync options (in
> nvidia-settings) set "correctly", right (i.e. the right combination
> of on/off).  I think Daniel K. is the only person in the world who
> understands them, so check for his posts.  Here's a starting point:
> http://www.gossamer-threads.com/lists/mythtv/users/269691#269691
> http://www.gossamer-threads.com/lists/mythtv/users/274295#274295
> http://www.gossamer-threads.com/lists/mythtv/dev/277331#277331
> Hmmm.  Guess I found the most important ones for you.

I must disagree with Daniel's and Mike's advice, at least for my own

With my Nvidia 6200TC-equipped frontend, I've always had to turn Sync
to VBlank (under Video Texture Adapter) *on*, not off, in the XVideo
section in nvidia-setup in order to get smooth playback with
Bob. ("Enable OpenGL Vertical sync for timing" in mythfrontend's
Setup|TV Settings|Playback doesn't matter very much for me, as RTC
timing works seemingly as well as OpenGL timing does. I do have
dev.rtc.max-user-freq=1024 in /etc/sysctl.conf.) Otherwise, I get
tearing in the upper one sixth of the screen, just as I reported in
and subsequently reported solved at, among other places,
I checked just now to see if things had perhaps changed with recent
versions of the proprietary Nvidia drivers, but no, same behavior with
9755, 0.20.2, and the 6200TC on my 1080p DVI flat panel.

I've described the output with my settings as better than a settop
and I stick by those words. That said, for all I know, were I to
upgrade to a card newer than my 6200TC, I could indeed follow Daniel's
advice and get video that's even better than what I currently have; I
really don't know. Anyone make a comparable jump and is able to report
back on the outcome?

Yeechang Lee <ylee at pobox.com> | +1 650 776 7763 | San Francisco CA US

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