[mythtv] Anyone looking at the XvMC/OSD glitches?

Daniel Thor Kristjansson danielk at mrl.nyu.edu
Thu Nov 25 16:47:46 UTC 2004


On Wed, 24 Nov 2004, Stephen Hocking wrote:
]When playing  HDTV live, One can get reliable playback and non-flickery OSDs 
]by disabling XvMC. However, this makes the CPU requirements insanely high. Has 
]anyone looked at what it would take to plunk the OSD display into the data 
]being sent off by the XvMC code, rather than it being dropped on top of it, 
]causing all sorts of weird interactions?

No one has looked into that. Are you volunteering? :)

My guess is that you could create fixup data and insert it. But you 
could probably only do this in I and P frames. For HDTV that would 
probably be every 5 frames, giving you an OSD frame rate of 6 fps. You 
would then need to zero the motion vectors near the OSD in both P and B 
frames.

It may be easier to just turn on frame skipping when the OSD is on 
screen. There are some remnants of a frameskipping patch here:
  http://www.mrl.nyu.edu/~danielk/mythtv/mpeg-frameskipping-v3.patch

-- Daniel



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