[MPlayer-users] fbdev: screensize is smaller than video size

[D Richard Felker III]

On Fri, Jul 11, 2003 at 03:56:36PM +0200, justin case wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> 
> > > i used to have the same problem, since i have a tv with vga in wich only
> > > accepts 640x480 and nothing else. a brilliant solution for me was using
> >
> > Impossible. Horizontal resolution does not exist in an analog video
> > signal. If it accepts 640x480, it also accepts 32x480, 12800x480, or
> > whatever you like, as long as you get the timings right (same as vga
> > 640x480).
> 
> well, impossible is a word i don't like. there might be a protective curcuit
> in there, that does dunnowhat.

No, I'm saying there's *no* *such* *thing* as horizontal resolution.
That information is gone by the time the signal gets out of the video
card. All you have is an analog signal that varies in voltage

> but actually what you say makes sense. after all i treid gettig different
> res out there very hard with no sucess. i used a ati card under windows, so

Of course, because windows does not offer any resolution with the same
timing as VGA but different horizontal resolution. I didn't say you
could use any mode you like, only modes with 480 visible scanlines
(actually you can adjust that slightly as long as you keep the
vertical total constant), same horizontal and vertical refresh rate as
vga, and same length sync pulses.

> i can be quite sure, it wasn't me tryinginvalid modelines but one i find the
> time, i'll investigate that again. thx for the hint.

Start with a modeline for VGA. Multiply dotclock and all four
horizontal timing numbers by W/640, where W is the width you want. It
should work.

> > > vesa. vesa seems to scale whatever res. you feed it in hardware (no
> > > cpu-usage and brilliant quality!) and even better - depending
> > on your grphic
> > > card - you can run vidix on top of it, if the vesa-output
> > causes any trouble
> > > (mine did cut the picture, looked like -double didn't work).
> >
> > It can only scale in hardware if you have vidix support. Otherwise
> > it's no better than fbdev.
> 
> i wrote it _sems_ so scale in hardware.
> simple little test: play a clip without -fs and -zoom on a slow machine that
> takes like 80% already for plain decoding - no chance to scale in software,
> right? now go for -fs and -zoom using vesa and you will get a beautifully
> scaled fullscreen video using right your 80% cpu.
> how can that be?

I'd have to see more specifics to tell you. Probably you enabled vidix
without realizing it, or else the performance just evens out by
cutting X out of the loop (X slows you down a LOT). As long as your
vesa res is close to the movie res, it won't take much additional time
to scale, since it's already converting colorspace anyway.

Rich