[FFmpeg-devel] [PATCH] avcodec/wavpack: check for overflow

[Michael Niedermayer]

On Mon, Jun 17, 2013 at 05:49:47PM +0200, Michael Niedermayer wrote:
> On Mon, Jun 17, 2013 at 10:54:28AM +0000, Paul B Mahol wrote:
> > On 6/15/13, Michael Niedermayer <michaelni at gmx.at> wrote:
> > > Fix integer overflow in fate
> > >
> > > Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> > > ---
> > >  libavcodec/wavpack.c |   10 ++++++++--
> > >  1 file changed, 8 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/libavcodec/wavpack.c b/libavcodec/wavpack.c
> > > index 47f598a..dd273f7 100644
> > > --- a/libavcodec/wavpack.c
> > > +++ b/libavcodec/wavpack.c
> > > @@ -581,8 +581,14 @@ static inline int wv_unpack_stereo(WavpackFrameContext
> > > *s, GetBitContext *gb,
> > >                      L2 = L + ((s->decorr[i].weightA * (int64_t)A + 512) >>
> > > 10);
> > >                      R2 = R + ((s->decorr[i].weightB * (int64_t)B + 512) >>
> > > 10);
> > >                  } else {
> > > -                    L2 = L + ((s->decorr[i].weightA * A + 512) >> 10);
> > > -                    R2 = R + ((s->decorr[i].weightB * B + 512) >> 10);
> > > +                    int64_t Lt = s->decorr[i].weightA * (int64_t)A + 512;
> > > +                    int64_t Rt = s->decorr[i].weightB * (int64_t)B + 512;
> > > +                    if ((int32_t)Lt != Lt || (int32_t)Rt != Rt) {
> > > +                        av_log(s->avctx, AV_LOG_ERROR, "sample overflow %d
> > 
> > This looks extremly ugly.
> 
> Iam quite aware of that, which is part of the reason why i posted this
> (aka do you know a less ugly solution?)

ping
anyone has a better solution ?
do any objections to the original patch remain ?

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

If a bugfix only changes things apparently unrelated to the bug with no
further explanation, that is a good sign that the bugfix is wrong.
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