[mythtv] mythtv] XvMC

[Daniel Kristjansson]

Note: I'm starting a new thread since the original was sent in
reply to another thread.

On Sun, 2006-06-25 at 19:09 -0700, jafa wrote:
> I am running a nVidia 5500 video card and have been trying to get
> XvMC to work...
> 
> The first issue is it plays both the audio and the video at half speed. 
> The video is otherwise perfect. The audio maintains sync - slow with a 
> constant stutter.
> It does this both with no de-interlace and with BOB de-interlace.
> 
> The second issue is that attempting to switch out of mythfrontend back 
> to the desktop while watching tv systematically locks up the system 
> requiring a hard-reset.

This sounds like the nVidia OpenGL vsync problem with drivers after
7xxx. This is why we recommended a particular version of the nVidia
driver when the 0.19 release came out.

If you use drivers newer than 7xxx, you need to disable OpenGL VSync
in the playback settings. To get reasonably decent timing you will
need to increase the RTC timing accuracy by typing this as root:
  echo 1024 > /proc/sys/dev/rtc/max-user-freq

With any nVidia driver make sure "OpenGL Settings : Sync to VBlank",
"X Server XVideo Settings : Video Texture Adaptor Sync To VBlank" and
"X Server XVideo Settings : Video Blitter Adaptor Sync To VBlank" are
all disabled in nvidia-settings. All of those options should be disabled,
even when OpenGL VSync is working (since it does it's own syncing).

-- Daniel