[FFmpeg-devel] [PATCH] ARMovie/RPL demuxer rev4

[Eli Friedman]

On Fri, Mar 28, 2008 at 5:44 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
>  >
>  > >  > +        if (offset >= 0xFFFFFFFFUL || video_size >= 0xFFFFFFFFUL ||
>  > >  > +            audio_size >= 0xFFFFFFFFUL)
>  > >  > +            error |= -1;
>  > >
>  > >  What exactly is this check good for?
>  >
>  > Overflow, so it doesn't silently accept 10000000000000 as an offset.
>
>  What is the problem if it does accept 10000000000000 as an offset?
>  And why is 0xFFFFFFFEUL different?
>
>  [...]

10000000000000 is outside of the range of representable values for a
long, and gets transformed into 0xFFFFFFFFUL, at least on a 32-bit
machine.

-Eli