choppier in 0.2.91

[Alain Seite]

On Thu, Nov 29, 2001 at 11:00:11AM -0800, Michael Flohr wrote:
> Christophe Massiot wrote:
> 
> > On Thu, Nov 29, 2001, Jeremy Bailin wrote:
> >
> > > I'd assumed it was XFree, since I've had other problems with 4.1.0 and
> > > will probably downgrade soon anyway, but by reinstalling vlc 0.2.82 from
> > > my old rpm I've discovered that it was at fault - with vlc 0.2.82 and the
> > > rest of the system unchanged, the video is smooth again.
> >
> > Could you try 0.2.91 with vlc -V sdl ?
> 
> -V sdl is completely screwed in vlc 0.2.9x .
> SDL tries to change the video mode of X to get fullscreen.

that's the main reason I use -V sdl : that way the CPU doesn't have to
scale the image .. and drop more frames (I have a K6-2 350MHz, ATI 3D Rage
Pro, kernel 2.4.6, Debian unstable).

there is another bug with -V x11, when I come back from fullscreen, in
opens a window the size of the screen (1280x1024) instead of the original
720x480(?) window !

I would like it to be able to choose the fullscreen method (video mode
change or scaling) in the command options or in a config file (why isn't
there a config file ?)

> However, with many DVDs this results not in fullscreen, but in
> a very much horizontally stretched video output which verically
> seems to be sqeezed, so the aspect ration is completely messed
> up.

the result depends on what mode vlc choose to switch to. I infer it chooses
the mode closest to the DVD's format (720x480 ? usually); in my config it
chooses the 768x576 mode I use for fullscreen TV watching (xawtv)).

> 
> By the way: I observe the same thing: vlc 0.2.9x is choppier
> than the older 0.2.8x releases, and I am using XFree 4.1.0 on

I haven't noticed that

> an ATI 128 rage mobility on an A20p Thinkpad. It seems that
> the problem must have to do with this graphics card, since other
> people reporting choppier performance also had an ATI rage
> mobility. And yes, switching back to the older 0.2.8x releases
> gives smooth playback again. So, it is vlc, and not X, which
> causes the problem.
> 
> I guess, that it is motion compensation which causes the problem.
> Maybe, the vlc people can check what has been changed in
> the motion compensation code. It seems that XFree 4.1.0 has
> now its own motion compensation in xvideo mode (at least or

my card (or its driver ?) doesn't support Xvideo either !

> the ATI driver), could it be that there is an unfortunate interference
> which makes things worse than better? I noticed that the worst
> choppines occurs when the whole picture moves due to a
> camera movement. So, in particular, sweeps over a landscape
> are really choppy, while standing pictures with some movement
> of, say, people inside is more or less ok.
> 
> I hope these observations and conjectures help a bit

I hope my remarks won't add confusion..

-- 
Alain SEITE (allan AT free DOT fr)

The superior man understands what is right; the inferior man understands
what will sell.
                -- Confucius