[FFmpeg-devel] [PATCH] Move param initialization and colorspace details from sws_getContext() to sws_init_context().

[Michael Niedermayer]

On Sat, Oct 02, 2010 at 01:24:03AM +0200, Stefano Sabatini wrote:
> On date Friday 2010-10-01 21:19:45 +0200, Stefano Sabatini encoded:
> > On date Thursday 2010-09-30 01:34:14 +0200, Michael Niedermayer encoded:
> > > On Thu, Sep 30, 2010 at 12:56:20AM +0200, Stefano Sabatini wrote:
> > > > On date Wednesday 2010-09-29 19:25:28 +0200, Michael Niedermayer encoded:
> > > > > On Wed, Sep 29, 2010 at 06:00:27PM +0200, Stefano Sabatini wrote:
> > > > > > Allow to automatically set the default parameters without explicitely
> > > > > > set them, also simplify conversion to the new sws_init_context() API.
> > > > > > ---
> > > > > >  utils.c |   18 +++++++-----------
> > > > > >  1 files changed, 7 insertions(+), 11 deletions(-)
> > > > > > 
> > > > > > diff --git a/utils.c b/utils.c
> > > > > > index 938af9e..bee5a3a 100644
> > > > > > --- a/utils.c
> > > > > > +++ b/utils.c
> > > > > > @@ -761,10 +761,17 @@ int sws_init_context(SwsContext *c, SwsFilter *srcFilter, SwsFilter *dstFilter)
> > > > > >      int dstW= c->dstW;
> > > > > >      int dstH= c->dstH;
> > > > > >      int flags;
> > > > > > +    c->srcRange = handle_jpeg(&c->srcFormat);
> > > > > > +    c->dstRange = handle_jpeg(&c->dstFormat);
> > > > > 
> > > > > that breaks user setted *Range
> > > > 
> > > > I'm aware but I cannot see a simpler way. A possibility would be to
> > > > introduce an hack external to this function, but then doesn't look
> > > > that good as well.
> > > > 
> > > > The problem is: how should the new API deal with JPEG colorspaces?
> > > > Currently when we want to use the JPEG colorspace we pass one of the
> > > > YUVJ* pixel formats. Avoiding this hack would mean to make the various
> > > > FFmpeg components (well, mainly codecs) explicitely define which
> > > > colorspace/range to use.
> > > 
> > > YUVJ* is deprecated
> > > so designing new code toward it doesnt feel very good at all
> > > 
> > > also i dont see a problem
> > > if YUVJ set Range appropriately
> > > if not dont touch Range and leave it at the default / what the usert did set
> > 
> > Currently this has to be done directly in the application (in this
> > case ffmpeg.c, right?), so I was thinking about creating a copy of
> > handle_jpeg(), which is ugly, while it should be duty of libavcodec to
> > do that, but I have yet to think which would be the better way.
> 
> More problems which should be addressed: libswscale only supports two
> values for the color range, 0 and 1, libavcodec uses an enum
> AVColorRange, so as the first thing libswscale should be updated
> (would this comport a major break?).

the enum also has just 2 values that matter (unspecified really is useless in
this context)


> 
> Then we should update all the libavcodec code which doesn't set
> adeguately the color_range.

yes

[...]]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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