Michael Reinelt a écrit :
I did some more tests yesterday, and I created lots of test pictures in 1024x768 and 1280x768 resolution. (Is there a place where I could provide them to the public?)
Send them via private mail, and I'll put them on my web space, along with the other ones. I get 107 page views (not image download) per month on this directory : it must be useful to some.
...
Next I played around with modes for viafb: I get a 1280x768 mode with this options:
modprobe viafb mode=1280x768 bpp=32 refresh=60 TVon=0
I get a quite good picture where the 1280x768 fit exactly onto the screen (after some fine-tunig in the TV setup). But as I feared: the horizontal resolution isn't that good. I get a sharp resolution vertically, I can see that one pixel on the TV directly corresponds to one pixel in the test image. Horizontally, the pixels are blurred over 2-3 pixels. I have to switch the TV into 16:9 mode, in 4:3 mode the image is scaled down to 1024 pixels. I'm afraid the TV does *always* scale down to 1024, and then back up to 1280. Who the hell did design this braindamadged thing???
Well, it is not really astoniching, taking into account the skills or common customers... I think they simply design their 16:9 panels with the same components as the 4:3 ones, and ignore anything that is not obvious. Since VGA as always been 4:3 (until a few years), they stick to it.
Next I tried to play around with 1024x768. Now for the bad news: I couldn't get a good picture here. First, the only way to get a signal on the TV is
modprobe viafb mode=1024x768 bpp=32 refresh=50 TVon=1 TVtype=1 TVoverscan=1
(note the TVon=1!!)
This places to VGA chip into special refresh rates that fit the TV encoder. These rates work with a multiscan monitor, but not with your TV. There again : cheap design.
As soon as I set TVon to 0, I get "no signal" or "not receiving" on the TV. Maybe some of the modes in viafb are wrong?
Might be, but IMHO the TV is also wrong.
But even with the TVon=1 mode, the resulting image isn't 1024x768, but somewhat smaller ( I suppose about 800x600 or so). I think here are some wrong mode values, too.
Since the TV encoder fits the image in a PAL frame, and does not do wonderful things, the VGA chip must provide degraded resolution, also shown on the VGA output.
Next I will play with softdevice and try to get VDR on viafb up and running.
Try my Debian package (http://nicolas.huillard.net/vdr/debian/ : recompile it) or the one from Tobias Grimm (improved from mine) in alioth.debian.org's SVN repository. Also softdevice and softplay developers prepare a release real soon now (this week-end).
Last questions: is this the right ML for this stuff, or is it a bit OT here?
The original post was slightly OT, and derived to completely OT in many directions... The right ML are softdevice-devel@berlios.de and directfb-users@directfb.org (viafb, DirectFB, TV-out). Start a new thread there.