OpenGL video performance

Greg G. dargllun at
Fri Jun 8 05:26:02 PDT 2012

On 25.04.2012 18:34, Greg G. wrote:
> Background: for some time now I've repeatedly trying to get my HD3200
> equipped mythtv box to use the OpenGL renderer. While things have gotten
> *much* better in the course of the last 1.5 years, I still find that Xv
> rendering is much more "real-time", meaning that when I use a proper
> deinterlacer (hard requirement) with Xv I get smooth rendering with no
> judder at all. WithOpenGL it's pretty jerky. My test case is to play
> some piece of recording from a news channel with a horizontal scoll text
> (like stock prices), this way you see even slight hickups. Note I'm not
> even talking about h.264 output (which is, btw, also great on Xv), but
> merely SD material.

I have now found out that I seem to be a victim of this bug:

[Bug 47007] HDMI monitor polling causing 100ms rendering stalls

When I 'echo N >/sys/module/drm_kms_helper/parameters/poll' things get
MUCH better!

However, now the HDMI hotplug doesn't work anymore. My HW is a RS780 on
Gigabyte GA-MA78GM-UD2H mainboard. As far as I understand the bug's
audit trail, what I observe would indicate that the manufacturer didn't
connect the hotplug pin properly. Is there anything else I can try to
disable polling and still have HDMI hotplug? I really need that, because
when my AVR is off, there is no EDID and thus I can't launch X. So
whenever I turn the AVR on/off, my X session will follow.


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