[FFmpeg-devel] [PATCH]lavc/pgssubdec: Fix palette colourspace

[wm4]

On Sun, 17 Apr 2016 17:54:00 +0000 (UTC)
Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:

> wm4 <nfxjfg <at> googlemail.com> writes:
> 
> > > > > Attached patch fixes ticket #4637 for me.    
> > >   
> > > > This looks like an entirely random change with no explanation 
> > > > or justification given.    
> > > 
> > > I don't understand:
> > > We have a sample that looks broken with current FFmpeg and fine 
> > > with the patch applied - what other explanation do you need?  
> > 
> > That would mean all PGS subtitles have been broken before, 
> > and nobody noticed.  
> 
> Don't you agree that for most samples, the difference 
> is difficult (or actually impossible) to see?

That doesn't make it correct.

> > What proves that the sample you have renders correctly now?  
> 
> Nothing.

So this doesn't exclude other error sources. For example, the PGS subs
could be stored in the video's colorspace, in which case the result
isn't correct (neither with or without patch applied).

I'd prefer it if such things had a real reasoning behind them, instead
of trial & error with single samples.

> 
> You think that it is more likely that the sample was 
> intentionally made to fool the vlc developers than to 
> help them?

No, but it could still be a coincidental result.