On Wed, Nov 09, 2016 at 08:52:54PM +0100, Andreas Cadhalpun wrote:
> On 09.11.2016 02:27, Michael Niedermayer wrote:
> > On Tue, Nov 08, 2016 at 10:36:01PM +0100, Andreas Cadhalpun wrote:
> >> Since the loop goes down to i = 0 the number of iterations (variable
> >> count) is the original i, not i - 1.
> >> In the case of i originally being 1, this miscalculation resulted in
> >> a division by zero.
> >>
> >> This problem was introduced in commit
> >> 4b90dcb8493552c17a811c8b1e6538dae4061f9d.
> >>
> >> Signed-off-by: Andreas Cadhalpun <andreas.cadhal...@googlemail.com>
> >> ---
> >> libavcodec/dvbsubdec.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/libavcodec/dvbsubdec.c b/libavcodec/dvbsubdec.c
> >> index e9f4765..31898ea 100644
> >> --- a/libavcodec/dvbsubdec.c
> >> +++ b/libavcodec/dvbsubdec.c
> >> @@ -810,7 +810,7 @@ static void compute_default_clut(AVSubtitleRect *rect,
> >> int w, int h)
> >> list_inv[ i ] = bestv;
> >> }
> >>
> >> - count = i - 1;
> >> + count = i;
> >> for (i--; i>=0; i--) {
> >> int v = i*255/count;
> >> AV_WN32(rect->data[1] + 4*list_inv[i], RGBA(v/2,v,v/2,v));
> >
> > with this a 2 color text would be 50% and 100% transparent
> > it should be transparent background and opaque text,
> > count = FFMAX(i - 1, 1);
> > seems better to me
>
> OK, patch doing that is attached.
>
> Best regards,
> Andreas
> > dvbsubdec.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > 10b117a15971daf75d61efe486b961d3cc59d480 > 0001-dvbsubdec-fix-division-by-zero-in-compute_default_cl.patch > From 436318575abf482e1ea144f651c47bc2730e41a2 Mon Sep 17 00:00:00 2001 > From: Andreas Cadhalpun <andreas.cadhal...@googlemail.com> > Date: Tue, 8 Nov 2016 22:32:42 +0100 > Subject: [PATCH] dvbsubdec: fix division by zero in compute_default_clut > > This problem was introduced in commit > 4b90dcb8493552c17a811c8b1e6538dae4061f9d. > > Signed-off-by: Andreas Cadhalpun <andreas.cadhal...@googlemail.com> > --- > libavcodec/dvbsubdec.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) LGTM thx [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB Avoid a single point of failure, be that a person or equipment.
signature.asc
Description: Digital signature
_______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
