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

Michael Niedermayer michaelni
Sun Sep 12 12:11:20 CEST 2010

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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