that's a non-interlaced source on an interlaced display.  try bob &
weave.  Does the g400 have a flicker filter?

On Sat, 2004-11-06 at 01:56 +0100, Lucian Muresan wrote:
> Stefan Lucke wrote:
> > On Donnerstag, 4. November 2004 15:22, Lucian Muresan wrote:
> ...
> >> so far) this has yet to be written :-). The DirtectFB videoout of 
> >> softdevice
> >> as it is now, uses wrong field parity order, which is very bad on an
> >> interlaced TV, especially on fast movements and scrolling text, especially
> > 
> > What kind of effects do you see ?
> > Now I tried s-video out and I see some kind of blocked stripes.
> > That is, one big horizontal stripe is left from the next. and this seems to 
> > be
> > a scaling issue. Width is reported as 720 pixels and so the whole picture
> > will be scaled down (scaler assumes square pixel).
> 
> I'm seeing a sort of smearing on fast movements, sometimes it looks like 
> comb artifacts, sometimes like some big blocks bundled in horizontal 
> stripes. Depending on the movements' speed matching a certain relation 
> (ratio? multiple?) to the framerate, these effects do or do not appear. 
> the fact is, they're more likely to appear on faster movements like 
> sports events or horizontal scrolling newstickers. The bigger blocking 
> appears more likely on almost vertical edges when moving horizontally 
> (imagine for example football players running in the field, or even try 
> to find such a programme and see for yourself).
> You could try this: Just record a short sequence of such material and 
> replay it within VDR/softdevice/DFB on TV, and then with
> 
> mplayer -vo dfbmga:buffermode=single:fieldparity=bottom
> 
> and you will notice how good they look alike, and then try
> 
> mplayer -vo dfbmga:buffermode=triple:fieldparity=top
> 
> on the same recording (first time I said "wow!"). Maybe the buffering 
> isn't the most important thing here, but triple helps stabilizing the 
> picture even when using the wrong parity. And I forgot one thing: dfbmga 
> also uses vertical sync, this could also matter a great deal in the 
> output quality.
> 
> Maybe softdevice shouldn't even try to use 768 pixels wide surfaces when 
> outputting to TV through the second head of a matrox. For the first 
> head, there are 4:3 resolutions with square pixels available, but I 
> guess not for the second, see below.
> 
> > I cannot specify 768 width in /etc/directfbrc. This will cause a segfault 
> > on "scrSurface   = dfb->CreateSurface (scrDsc);" allthough 768 is reported
> > as supported:
> > [dfb] Supported video Modes are: [EMAIL PROTECTED] [EMAIL PROTECTED] [EMAIL 
> > PROTECTED] [EMAIL PROTECTED] [EMAIL PROTECTED] [EMAIL PROTECTED]
> > 
> > Nov  5 19:44:19 bodega1 kernel: matroxfb: cannot set xres to 720, rounded 
> > up to 768
> 
> Yes, AFAIK, for crtc2 only 720x576 is supported for PAL, or 720x480 for 
> NTSC (see DirectFB/gfxdrivers/matrox/matrox_[screen_]crtc2.c), which are 
> both standard video resolutions (well, at least still "usual" nowadays), 
> so yes, the pixels aren't sqare, but that shouldn't be a problem. I 
> think what DFB reports as supported has only something to do with 
> /etc/fb.modes, but unfortunately not taking into account that you set up 
> crtc2 in /etc/directfbrc, then I think in case of Matrox cards, only the 
> code in the 2 files mentioned above is relevant.
> 
> Just for reference, if you compare vdr replay and mplayer like above, my 
> /etc/directfbrc:
> 
> mode=720x576
> depth=32
> primary-layer=2
> matrox-crtc2
> matrox-sgram
> matrox-tv-standard=pal
> matrox-cable-type=scart-rgb
> 
> disable-module=joystick
> disable-module=ps2mouse
> disable-module=lirc
> 
> 
> 
> Lucian Muresan
> 



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