I have been experimenting with this. Problem is that chain is too *perfect*.
You start to see too much mpeg artifacts (blocking and color differences) that
it looks like you need much software/processing power to make picture viewable.
On CVBS we have 'hardware' blur filter which eliminates this problem.. :-)
You are quite right on this one, if we are talking about very poor quality
of Finnish DVB broadcasts, damn under 3000 kbits/sec/channel VBR cannot be
good.
Said that, I am not building this system only for DVB-t, but
also want to view some DVB-s and DVD:s on my VDR-system.
Yes, I also have DVB-S card currently running. And DVD playback is also a feature I'll
add after I get everything working.
But as you probably know, many DVB-S streams are not full PAL resolution. They might
be like 480x576 (SVCD resolution).
Please do keep the list or at least me :) informed of your
findings on your quest to get good picture using software methods.
I did some testing with raw mplayer playing. I tested with 'Urheiluruutu'
which has all videotypes in it
- live picture directly broadcasted from cameras
- computer graphics (results)
- edited material of sports events
- good quality, in house editing
- or via satellite relay
I would say that the original material matters MUCH. And it seems that
on worst case this quality changes within one program.
- all live picture & computer graphics was fine with just deinterlacing
- English Premiership football clips were very bad. Nothing could help
them. This is because there is a lot 'noise' like information in grass.
- Ice hockey was also problematic but deblocking helped a bit.
- Alpine skiing had a lack of details. Athlete and white background with poles.
It was very hard to find good settings and those settings should be automatic
or at least configurable via remote control. Some noise filter even added
artifacts into computer graphics so image quality was worse.
And at the same time these effects are not so noticeable when using via CVBS
signal. You can see that the football is not so good quality but you don't mind
that so much. On DVI the difference is huge at least with 72" screen.
Have you tried e.g. mplayer's postprocessing filters? They are
smoothening and de-sharpening the picture (basically worsening the image
quality in terms of PSNR but making them more pleasing your eyes) - this
has a similiar effect like the low-quality analog TV-outs of your RGB
CVBS output of your full-featured card...