radeon overlay tap coefficients / filtering question

[Roland Scheidegger]

I don't really understand the xv code in radeon_video.c (way too many 
magic numbers), but as far as I can see the driver does indeed not use 
the tap coefficients which are programmed (presumably these give higher 
quality than the hard-coded ones?). Some quick tests (using bogus 
coefficients) seems to confirm that. Is there some reason why they 
aren't used, or should RADEON_OV0_FILTER_CNTL be changed to use 
FILTER_PROGRAMMABLE_COEF instead of FILTER_HARDCODED_COEF?
Also, those unused values are written twice, and unless there is some 
weird hw error requiring this I assume this is a copy & paste bug and 
the first one of these blocks should be removed?

(btw the reason I was looking at that code was 
https://bugs.freedesktop.org/show_bug.cgi?id=1462 though I unfortunately 
have absolutely no solution or idea for that, other than it SEEMS to 
work with some other OS (quicktime for instance always uses textured 
video, I managed to get some hd mp4 clip running with the ati control 
panel overlay controls working but the driver could be faking it I guess.)

Roland