[FFmpeg-devel] [PATCH] swscale: avoid overread in planar2x

[Michael Niedermayer]

On Sun, Sep 12, 2010 at 12:11:58AM -0300, Ramiro Polla wrote:
> Hi,
> 
> The MMX2/3dnow code in planar2x in rgb2rgb currently reads one byte
> prior to the source buffer. This leads to a crash on Windows and Mac
> OS X when the buffer is allocated on the beginning of a page. This
> should also be a problem on Linux but I haven't seen many crashes
> because of overreading...

the code looks buggy
the first pixel should be [0] not [-1] that can be achived by
moving the reading code of it to the end of the loop and constructing
the contents of the first mm4 outside the loop

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

Democracy is the form of government in which you can choose your dictator
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