| Message ID | 6d200416-f02f-370b-3e15-c0bc58792bd1@googlemail.com |
|---|---|
| State | Superseded |
| Headers | show |
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.Cadhalpun@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 [...]
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));
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.Cadhalpun@googlemail.com> --- libavcodec/dvbsubdec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)