[mythtv-users] improve upscaling quality?

[Gordon McLellan]

I need some tips and suggestions on improving playback quality of SD
programming on my new HD tv.

When viewing SD recordings (recorded off cable or dvd backups) under
myth the picture looks like I'm watching it through a piece of waxed
paper or someone coated the camera lens with petroleum jelly.  I also
get a lot of interlacing artifacts during rapid movement.  I'm running
Jean-Yves version of 0.21-fixes and have vdpau working wonders for
playing back 720p and 1080i content more easily on my old athlon
3400+.   Under my playback rule I have tried setting various
de-interlacers on a rule set to match recordings <= 1280x720.  Is
there anyway to use the power of vdpau to upscale the SD content,
similar to what the DSP in my TV and Cable box can do?  Watching an SD
recording on the TV looks awesome, the cable box doesn't upscale quite
as well, but is still a lot better than what I get under myth.  I'm
not blaming myth, as it is probably nvidia's fault or xorg, but I am
hoping that myth might have some tricks to get better quality?

I've tried using the custom resolution feature under myth, but it is
unable to change resolutions, it tries, because the TV shuts down for
a few seconds and then comes back on, but it alway comes back on at
1920x1080 at 60hz.

Details:

Athlon64 3400+, 3g of ram
32-bit ubuntu 810, all stock repos except for Jean-Yves myth related
and his version of the nvidia driver.
Geforce 8400GS video card (512m)
Samsung LN52A650 Series 6 Display, connected via DVI to HDMI cable
using HDMI2 input, labeled as "PC"