[MPlayer-dev-eng] [PATCH] Possible SDL aspect bug, quick workaround

[Fredrik Roubert]

On Tue 19 Aug 22:59 MEST 2003, Felix Buenemann wrote:

> > > > > I'm not sure wheter this is an actual bug in MPlayer, or if I just
> > > > > don't understand how MPlayer is supposed to work well enough.
> > > > > However, this causes a lot (maybe most) of my files to be scaled
> > > > > when played in fullscreen mode (sdl:dga), which is a big performance
> > > > > penalty on the system I'm using.
> > > >
> > > > What happend to that patch ?
> > > > It's still not applied neither is Alex alternative version.
> > >
> > > I'm not an SDL specialist..someone familiar should have a look at it.
> >
> > Atmos?
>
> the aspect code works as expected, as Fredrik is using a resolution of 720x480
> which gives an aspect of 1.5 but he is using a CRT (I presume), which has an
> aspect of 4:3 (1.333), this requires the video to be rescaled in order to
> give proper aspect at this resolution. Additionally to this fact the sample
> file he tries to play has a bad resolution aswell, as it carries the original
> anamorphic NTSC dvd resolution, which should be rescaled, when ripping to avi
> to either:
>
> - 720x400 when leaving the black bars above and below (16:9 / 1.777 aspect)
> - 640x480 (720x540) when dvd has 4:3 (1.333) aspect
> - 720x304 when cropping a 2.35:1 movie
> - 720x384 when cropping a 1.85:1 movie
> - 720x320 when cropping a 2.21:1 movie (rare aspect)
>
> So assuming the movie comes from 16:9 dvd and is uncropped/unrescaled, he
> should play it using mplayer -aspect 16:9 movie.avi

OK, I see. It's nice to hear that this wasn't a bug in MPlayer.

However, this behaviour (as correct as it might be) makes it impossible
to play a lot of files on my system (and I don't beleive I'm the only
MPlayer user with an old computer), so I think it would be a good idea
to make this scaling optional. Often the aspect differences are small
enough to make a nice viewing experience even without scaling.

One way to make this scaling when using -vo sdl:dga optional, is to only
scale the movie if the opton -zoom was also given. This is what my patch
does:

http://mplayerhq.hu/pipermail/mplayer-dev-eng/2003-May/018669.html

Another way could be to introduce a new option, to prohibit scaling in
this situation explicitly. But I think that the use of -zoom corresponds
the closest to how MPlayer behaves for other outputs.

Opinions? Suggestions?

Cheers // Fredrik Roubert

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