[MPlayer-cvslog] CVS: main/libmpcodecs ve_lavc.c,1.113,1.114

[Michael Niedermayer]

Hi

On Monday 09 May 2005 05:12, Rich Felker wrote:
> On Mon, May 09, 2005 at 03:07:42AM +0200, Michael Niedermayer wrote:
[...]
> > > > > Also colors didn't really look wrong to me (though my eyes (and
> > > > > esp. LCD) aren't that good).
> > > >
> > > > well, tell this to the first user who notices that his lossless jpeg
> > > > encodings look the same but arent
> > >
> > > They're lossless if you decode them with MPlayer/MEncoder, which also
> > > assumes standard YUV colorspace when decoding jpeg..
> >
> > a bug in mplayer canceling out a bug in mencoder ...
>
> imo it's not a bug. conversion back and forth between standard yuv and
> jpeg yuv is not lossless, so if you have a yuv image to begin with and
> you want to compress it _losslessly_ with jpeg, the only way to do so
> is to treat it as if it were jpeg colorspace even though it's not..
>
> the fact that the jpeg stream doesn't carry with it a tag for the
> original colorspace is a loss of sorts, but as long as you keep your
> files tagged properly it's not a problem.

with strict=-1 our jpeg decoder does store a user data/comment tag in the 
stream about the colorspace, obviously that doesnt work if the wrong 
colorspace info is given to lavc

[...]
-- 
Michael