On Tue, Jan 06, 2009 at 01:17:52AM +0200, Jukka Vaisanen wrote: > Yes, it's a good idea to get 1:1 pixel mapping on your display. Double > scaling (first pc, then display) is not a good idea, ever. > > But, some problems arise: > > HDMI uses DVI signalling for the video (and audio is hidden in a > vertical blanking time slot believe it or not) so it may seem like just > another connector.. however in their finite wisdom the HDMI > standardization people decided that HDMI will not support arbitrary > resolutions, but instead only the existing (and back then, planned) > broadcast resolutions: > > - 576i/p (pal) and 480i/p (ntsc) > > - 720p (1280x720) > > - 1080i and 1080p (1920x1080) > > The world is full of TVs with 1366x768 and other weird resolutions. > There are also plasmas with 1024x768 etc "standard computer > resolutions". The big surprise to many people is that even though DVI > signalling could carry these native resolutions, the displays themselves > won't accept / sync to them. And they don't advertise them in the EDID > data so you have to force your computer to that resolution / refresh to > even try it (and fail). > > The only true 720p displays I have seen are rear-projection TVs and > data/av projectors. They will accept their native resolution of 1280x720 > over HDMI, however getting rid of overscan to get 1:1 is another > matter.. > > Then a solution: > > I used to have a Panasonic plasma with a similar non-standard resolution > and I used the VGA port with it to automatically get a 1:1 pixel display > as it's intended for PC display use. Yes VGA is not optimal but at that > resolution and a 1 meter cable, who cares... Today I have a full HD > 1920x1080 panel with an option for "exact scan" which gives me 1:1 > pixels (without overscan) out of the box over HDMI, I just run normal > 1920x1080@60Hz out of my computers. > > And finally a question: > > If someone can tell me how to get 576i over HDMI out from VDR, please > do. That way I could use my external HQV Reon video scaler to upscale > it.. Of course it would need to allow me to switch modes for 720p and > 1080i also based on broadcast resolution ;) > Hello. Please check this thread: http://www.linuxtv.org/pipermail/vdr/2008-July/017347.html Original patches: http://lowbyte.de/vga-sync-fields/ New version: http://www.vdr-portal.de/board/thread.php?threadid=80567 Those might help.. they're about getting pure 1:1 interlaced (576i) RGB output from a VGA card.. and the new version also has some HDTV stuff, I guess. I don't read german so i'm not familiar with that.. There are also patches to maintain perfect field sync to DVB stream to avoid tearing/stutter/jerkiness. -- Pasi _______________________________________________ vdr mailing list vdr@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/vdr
