[mythtv-users] Any success with Intel graphics hardware and judderfree playback?

[William Powers]

On Oct 3, 2012, at 3:49 PM, Kenni Lund <kenni at kelu.dk> wrote:

> Hi list
> 
> I'm considering replacing my main (ION-/Atom-based) frontend with a
> Intel Ivy Bridge solution with integrated graphics, as a workaround
> for #11115.
> 
> I want to make sure that it works well before I purchase the new
> hardware. Therefore I've hooked up my Ivy Bridge laptop to my TV with
> a HDMI cable and have started testing.
> 
> My initial testing were moderately positive, playback worked with any
> OpenGL or regular playback profile (Slim/Normal/High Quality).
> 
> However, I did see a few issues:
> 1. A horizontal flickering line was consistently seen on some
> recordings -> Likely fixable with some Xorg/driver parameter.
> 2. Judder -> Fixable with http://www.mythtv.org/wiki/User_Manual:JudderFree
> 3. Picture quality was slightly lower than when using VDPAU on the
> same TV -> That I'll probably just have to live with.
> 
> Judder was the first thing I tried to fix. Once I had Xorg and all
> modelines configured, I ran into what at first sight appears to be a
> bug in MythTV. Every time when MythTV starts playback and changes the
> resolution from the desktop default 1920x1080 at 60Hz to 1920x1080 at 50Hz,
> the picture gets moved vertically by an offset, causing a black bar at
> the top of the screen while the bottom of the picture is missing:
> http://postimage.org/image/wyf7m7rnt/
> 
> It is supposed to look like this (notice the extra text in the bottom
> of the screen):
> http://postimage.org/image/4yfpfodl5/
> 
> It's not an invalid modeline, the issue is only in MythTV, as
> illustrated by the following picture:
> http://postimage.org/image/m3dd9lsgb/
> 
> So, I guess my question it: Has anyone succeded in creating a frontend
> based on Intel-hardware with integrated graphics and with judderfree
> playback?

I have been very pleased with OpenGL playback on Sandy Bridge hardware.  Previously, it required jumping through some hoops to get a new enough version of the Mesa libraries, but a recent Fedora 17 install worked right out of the box.  I have no visible tearing with the X composite extension disabled.  Previously I got a single flickering line of green pixels at the bottom of the screen, which could be eliminated by offsetting the picture by one line, but the recent Fedora 17 install doesn't exhibit that behavior.

I haven't seen any judder.  The biggest problem for picture quality was picking a deinterlacer. I finally settled on GreedyHighMotion (2x) which, to my eye, looks as good as VDPAU Temporal, 2X.  However, it's a software interlacer and won't work with anything slower than a G620 and I recommend an i3 to be sure.