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

[D Richard Felker III]

On Thu, Oct 16, 2003 at 04:46:35PM +0200, Fredrik Roubert wrote:
> 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?

Huh? The scaling values generated by aspect() are only used when a
hardware scaler is available, or when -zoom and -vf scale are used. At
least that's the way it's supposed to work. Maybe vo_sdl is broken and
thinks it has an overlay because SDL is emulating it in software or
something stupid...

Rich