[MPlayer-users] Radeon VESA (vidix) jerky/juddery at fullscreen resolutions

[Brian J. Murrell]

[Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
OK, 

I have been here with this problem before but I have more information.
I am experiencing _very_ jerky (juddery) playback on my Radeon
equipped playback machine.  I did some experiments and here is what I
found.

I have a 320x240x29.94fps video.  If I play it with:

-vo vesa:vidix -double

I get very jerky output.  It's almost like every so often (every
second or less) or so it goes back and plays a few earlier played
frames -- if that explanation makes any sense.  So like if the fps
were 5fps and the frames were numbered 1 - 20, playback looks like
it's:

1 2 3 1 2 4 5 6 7 4 5 8 9 10 11 7 8 12 13 14 15 12 13 16 17 18 14 15 19 20

I can't quite tell if the repeated frames are being inserted between
or replacing later frames.  Heck I don't even really know that's what
is happening.  It just looks like that.

With the options "-vo vesa:vidix -double", I get the following
(interesting bits) output:

Movie-Aspect is undefined - no prescaling applied.
VO: [vesa] 320x240 => 320x240 Planar YV12 
...
vo_vesa: Using VESA mode (10) = 194 [320x240 at 0]
vo_vesa: Using DGA (physical resources: D0000000h, 02000000h)
vo_vesa: Using VIDIX

However!  If I force a larger VESA mode with something like:

-screenw 640 -screenh 480 -vo vesa:vidix -double

I get much(! but not perfect) smoother output.  It's a 320x240 display
on a 640x480 screen (with big black borders around it).  The pertinent
mplayer bits:

Movie-Aspect is undefined - no prescaling applied.
VO: [vesa] 320x240 => 320x240 Planar YV12 
...
vo_vesa: Using VESA mode (35) = 111 [640x480 at 0]
vo_vesa: Using DGA (physical resources: D0000000h, 02000000h)
vo_vesa: Using VIDIX

I get the same kind of good results if I force VESA to 800x600 as
well.

However!  If I use the following command line options:

-fs -screenw 640 -screenh 480 -vo vesa:vidix -double

I am back to a fullscreen but again jerky (juddery) output.  If I use
the following switches:

-x 640 -y 480 -zoom -screenw 640 -screenh 480 -vo vesa:vidix -double

again, I get jerky output with the following interesting mplayer
debug:

VO: [vesa] 320x240 => 640x480 Planar YV12 zoom 
...
vo_vesa: Using VESA mode (35) = 111 [640x480 at 0]
vo_vesa: Using DGA (physical resources: D0000000h, 02000000h)
vo_vesa: Using VIDIX

So it seems that no matter what kind of display resolution and scaling
factors I use, if I display fullscreen I get jerky output but if I
display in a larger resolution and it's not scaled to full screen it's
smooth.

Any ideas why?

b.

--
Brian J. Murrell