[FFmpeg-devel] swscale merge

[Michael Niedermayer]

Hi

On Wed, Jun 29, 2011 at 08:56:13PM -0700, Ronald S. Bultje wrote:
> Hi,
> 
> On Wed, Jun 29, 2011 at 8:23 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
[...]
> > +    for (i = 0; i < width; i++)
> > +        dst[i] = (FFMIN(dst[i],30189)*19077 - 39057361)>>14;
> >                                ^^^^^
> > clips the 32bit values incorrectly
> 
> Fixed (roughly).
>

> >                                                       ^^^^^
> > overflows
> 
> No.

it does overflow, look:
commit e0b8fff6c7a293e35079ba1931bd19372686b3f6
Author: Ronald S. Bultje <rsbultje at gmail.com>
Date:   Wed Jun 29 21:04:45 2011 -0700
...
 for (i = 0; i < width; i++)
-        dst[i] = (FFMIN(dst[i],30189)*19077 - 39057361)>>14;
+        dst[i] = (FFMIN(dst[i],30189<<4)*19077 - (39057361<<4))>>14;
 }

(30189<<4)*19077 = 9214648848
1<<32            = 4294967296

did i forget to say, you will add this bug when you fix the other ?
:)

you still dont want me to review your patches before you push them ?

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

The bravest are surely those who have the clearest vision
of what is before them, glory and danger alike, and yet
notwithstanding go out to meet it. -- Thucydides
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