[FFmpeg-devel] [PATCH] swscale alpha channel support

[Kostya]

On Mon, Feb 23, 2009 at 04:22:23PM +0100, Michael Niedermayer wrote:
> On Mon, Feb 23, 2009 at 04:16:44PM +0100, C?dric Schieli wrote:
[...]
> > Index: ffmpeg/libswscale/yuv2rgb2.c
> > ===================================================================
> > --- ffmpeg.orig/libswscale/yuv2rgb2.c	2009-02-23 15:14:39.409161445 +0100
> > +++ ffmpeg/libswscale/yuv2rgb2.c	2009-02-23 15:17:36.861446441 +0100
> > @@ -83,11 +83,11 @@
> >      g = (void *)(c->table_gU[U] + c->table_gV[V]);  \
> >      b = (void *)c->table_bU[U];
> >  
> > -#define PUTRGB(dst,src,i,o)          \
> > -    Y = src[2*i+o];                  \
> > -    dst[2*i  ] = r[Y] + g[Y] + b[Y]; \
> > -    Y = src[2*i+1-o];                \
> > -    dst[2*i+1] = r[Y] + g[Y] + b[Y];
> > +#define PUTRGB(dst,src,i,o,a)              \
> > +    Y = src[2*i+o];                        \
> > +    dst[2*i  ] = r[Y] + g[Y] + b[Y] + (a); \
> > +    Y = src[2*i+1-o];                      \
> > +    dst[2*i+1] = r[Y] + g[Y] + b[Y] + (a);
> >  
> >  #define PUTRGB24(dst,src,i)                                  \
> >      Y = src[2*i];                                            \
> 
> alpha can be merged in the table i think which avoids that 1 add per pixel

I don't think so - it's independent channel that is copied between different
formats (YUV, RGB, whatever).
 
> [...]
> -- 
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB