[FFmpeg-cvslog] avfilter/vf_gblur: fix undefined behaviour

[Paul B Mahol]

ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Wed Oct 16 19:21:00 2019 +0200| [1e35519fe0b8bbad84641e83d49138152720b544] | committer: Paul B Mahol

avfilter/vf_gblur: fix undefined behaviour

Fixes #8292

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=1e35519fe0b8bbad84641e83d49138152720b544
---

 libavfilter/vf_gblur.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavfilter/vf_gblur.c b/libavfilter/vf_gblur.c
index 9b3e168b1d..803d3e3df4 100644
--- a/libavfilter/vf_gblur.c
+++ b/libavfilter/vf_gblur.c
@@ -157,6 +157,7 @@ static int filter_postscale(AVFilterContext *ctx, void *arg, int jobnr, int nb_j
 {
     GBlurContext *s = ctx->priv;
     ThreadData *td = arg;
+    const float max = (1 << s->depth) - 1;
     const int height = td->height;
     const int width = td->width;
     const int64_t numpixels = width * (int64_t)height;
@@ -166,8 +167,10 @@ static int filter_postscale(AVFilterContext *ctx, void *arg, int jobnr, int nb_j
     float *buffer = s->buffer;
     unsigned i;
 
-    for (i = slice_start; i < slice_end; i++)
+    for (i = slice_start; i < slice_end; i++) {
         buffer[i] *= postscale;
+        buffer[i] = av_clipf(buffer[i], 0.f, max);
+    }
 
     return 0;
 }