[FFmpeg-devel] [PATCH] avcodec/apedec: fix undefined left shifts of negative numbers

[Paul B Mahol]

On 9/25/15, Ganesh Ajjanagadde <gajjanagadde at gmail.com> wrote:
> On Sat, Sep 19, 2015 at 10:18 PM, Ganesh Ajjanagadde
> <gajjanagadde at gmail.com> wrote:
>> This fixes -Wshift-negative-value reported with clang 3.7+, e.g
>> http://fate.ffmpeg.org/log.cgi?time=20150919172459&log=compile&slot=x86_64-darwin-clang-polly-notiling-3.7.
>> Note that the patch crucially depends on int >= 32 bits,
>> an assumption made in many places in the codebase.
>>
>> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
>> ---
>>  libavcodec/apedec.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
>> index 5536e0f..7b34d26 100644
>> --- a/libavcodec/apedec.c
>> +++ b/libavcodec/apedec.c
>> @@ -1281,7 +1281,7 @@ static void do_apply_filter(APEContext *ctx, int
>> version, APEFilter *f,
>>              /* Update the adaption coefficients */
>>              absres = FFABS(res);
>>              if (absres)
>> -                *f->adaptcoeffs = ((res & (-1<<31)) ^ (-1<<30)) >>
>> +                *f->adaptcoeffs = ((res & (-(1<<31))) ^ (-(1<<30))) >>
>>                                    (25 + (absres <= f->avg*3) + (absres <=
>> f->avg*4/3));
>>              else
>>                  *f->adaptcoeffs = 0;
>> --
>> 2.5.2
>>
>
> ping
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>

I guess its fine if fate passes.