[vdr] Re: Interlacing

[Nicolas Huillard <nhuillard@ghs.fr>]

Lucian Muresan a écrit :
> While talking about softdevice and DirectFB, last night I managed to get 
> it working on my TV, by forcing the layer selection in the softdevice 
> source code. Nicolas, I understood you are also dealing with 
> softdevice/DFB for some time, I'd like to ask you few things:
> If my graphic card's crtc2 layer (Matrox G400) says it supports changing 
> of the field parity,  shouldn't that improve tearing artifacts on faster 
> movements and for example, on gliding text in news tickers or movie 
> credits? How does it behave on your hardware?
Live TV on some channels is still very jerky (rendering speed is much 
lower than normal, and there is a time-compression each few seconds to 
compensation), but I don't watch much live TV.
Recordings sound has clicks, and sound like if there was constant 
resampling. This is particulairly awful when playing music, where the 
beat is not at all regular. I still have to provide sample recordings, 
but I need first to make sure this is not related to my setup (sound 
artifacts are not the same when I change the fb.modes timings and TV 
output config of the vt1622 chip (tied to the cle266)...

> For now, I only managed to display both the video, and the OSD on the 
> same layer. The Matrox G400 DH also has a sub-picture layer which could 
> alpha-blend the OSD in hardware, but it doesn't work in the pixelformats 
> offered by sofdevice. It only works with YUY2 for me, on the same layer 
> with the video (therefore, a bit too CPU-intense). What is supposed to 
> be transparent in the OSD anyway, just the gray area, or the yellow 
> stuff in ST:TNG or the colored buttons, too? I can see the video only 
> through the grey OSD background, and it looks good, I don't think it 
> uses the dithering trick Stefan Lucke added lately on torgeir Veimo's 
> suggestion.
I didn't look at the latest softdevice yet, but what you describe make 
me think the dithering does the stuff (this fits the description Torgeir 
gave). I didn't ever have transparent OSD (grey background is fully 
transparent, and colors are opaque).
Everything is supposed to be transparent. I had it with softmpeg when I 
did experiment with it.

> Anyway, there are still some things that need to be improved with 
> softdevice/DFB, but after what I've seen last night on TV, I like it!
I am also happy with it, but on some channels. Others are awful on live 
TV, and recordings are not the best (naturally, those are the ones I am 
most inclined to watch). I'll come back with samples when I dig into a 
code much more than I did.

--
NH