[mythtv-users] stuttering video in LiveTV with greedy2x and yadif2x

[Tino Keitel]

Hi folks,

I had stuttering video in MythTV and now found the culprit. It seems to
be caused by a strange Xorg behaviour (or bug?). I set the refresh rate
to 60 Hz using xrandr --rate 60. However, if I check xvidtune, it still
shows 50 Hz. After running xrandr --rate 60 again, xvidtune shows 60
Hz.

And after running xrandr --rate 60 a second time, the stuttering video
doesn't seem to occur anymore.

I tried again and was able to reproduce that. Here is what I did:

$ xrandr --rate 50
$ xrandr --rate 50
$ xrandr -q | grep "  1024"
   1024x768       50.0*+   60.0     40.0

$ xvidtune -show
"1024x768"     54.16   1024 1048 1184 1344    768  771  777  806 -hsync -vsync

$ mythfrontend -> stutter happens

$ xrandr --rate 60
$ xrandr -q | grep "  1024"
   1024x768       50.0 +   60.0*    40.0
                           ^^^^^
                        reported 60 Hz
$ xvidtune -show
"1024x768"     54.16   1024 1048 1184 1344    768  771  777  806 -hsync -vsync
               ^^^^^
           but no real changes

$ mythfrontend -> stutter happens

$ xrandr --rate 60
$ xrandr -q | grep "  1024"
   1024x768       50.0 +   60.0*    40.0

$ xvidtune -show
"1024x768"     65.00   1024 1048 1184 1344    768  771  777  806 -hsync -vsync
               ^^^^^
        now it really changed

$ mythfrontend -> no stutter happens

I use Xorg server 1.4.2 and the Intel driver 2.3.2 on a i965GM chipset.

Regards,
Tino