[FFmpeg-devel] [PATCH]Fix tiff grayscale palette

[Michael Niedermayer]

On Mon, Sep 05, 2011 at 10:56:02PM +0200, Carl Eugen Hoyos wrote:
> On Monday 05 September 2011 06:25:37 pm Michael Niedermayer wrote:
> > On Mon, Sep 05, 2011 at 03:03:13PM +0000, Carl Eugen Hoyos wrote:
> > > Michael Niedermayer <michaelni <at> gmx.at> writes:
> > > > > +++ b/libavcodec/tiff.c
> > > > > @@ -294,8 +294,8 @@ static int init_image(TiffContext *s)
> > > > >  } else {
> > > > >      /* make default grayscale pal */
> > > > >      pal = (uint32_t *) s->picture.data[1];
> > > > > -    for (i = 0; i < 256; i++)
> > > > > -        pal[i] = i * 0x010101;
> > > > > +    for (i = 0; i < 1<<s->bpp; i++)
> > > > > +        pal[256 - (1<<s->bpp) + i] = i * 255 / ((1<<s->bpp) - 1) *
> > > > > 0x010101;
> > > >
> > > > filling the top only looks a bit strange why is it not
> > > > pal[0..(1<<bpp)] ?
> > >
> > > That doesn't work / shows wrong colours because TIFF_INVERT triggers
> > > "src[i] = 255 - src[i]" in the decode function.
> > >
> > > Should the palette be filled from both ends?
> > > Or is there a better solution?
> > 
> > invert (1<<bpp-1) - src[i] instead of 255 - src[i]
> 
> New patch attached.
> 
> Please comment, Carl Eugen

>  tiff.c |    6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 3cd2658ab0315fa79da819882cb67cb75af10136  patchtiffgray.diff

LGTM

[...]

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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Republics decline into democracies and democracies degenerate into
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