[FFmpeg-devel] [PATCH] ffmpeg: avoid possible undefined behavior

[Michael Niedermayer]

On Fri, Oct 09, 2015 at 10:39:27AM -0400, Ganesh Ajjanagadde wrote:
> On lines 1633,1634 FFABS(pts) is performed. However, if av_stream_get_end_pts
> returns AV_NOPTS_VALUE always, pts remains stuck at INT64_MIN, leading
> to undefined behavior on FFABS.
> 
> One could conceive of a solution using FFNABS. However, such a solution
> has to deal with the implementation defined rounding of integer division
> with at least one negative operand in ANSI C89. C99 forces truncation to
> zero, but I am not sure that all of our platforms compile with full C99
> support, and in particular whether we can safely assume a fixed
> rounding behavior across all platforms.
> 
> This solution is simple, and I doubt changing INT64_MIN to INT64_MIN + 1
> has any practical loss - if it is stuck at its initial value, the stream
> is messed up anyway.
> 
> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
> ---
>  ffmpeg.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

applied

thanks

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

Old school: Use the lowest level language in which you can solve the problem
            conveniently.
New school: Use the highest level language in which the latest supercomputer
            can solve the problem without the user falling asleep waiting.
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