[FFmpeg-devel] [PATCH 1/2] lavfi/showspectrum: fix crash in case of negative linesize

[Paul B Mahol]

Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 libavfilter/avf_showspectrum.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/libavfilter/avf_showspectrum.c b/libavfilter/avf_showspectrum.c
index 058f22c..c87812f 100644
--- a/libavfilter/avf_showspectrum.c
+++ b/libavfilter/avf_showspectrum.c
@@ -211,9 +211,11 @@ static int config_output(AVFilterLink *outlink)
         if (!outpicref)
             return AVERROR(ENOMEM);
         outlink->sample_aspect_ratio = (AVRational){1,1};
-        memset(outpicref->data[0],   0, outlink->h * outpicref->linesize[0]);
-        memset(outpicref->data[1], 128, outlink->h * outpicref->linesize[1]);
-        memset(outpicref->data[2], 128, outlink->h * outpicref->linesize[2]);
+        for (i = 0; i < outlink->h; i++) {
+            memset(outpicref->data[0] + i * outpicref->linesize[0],   0, FFABS(outpicref->linesize[0]));
+            memset(outpicref->data[1] + i * outpicref->linesize[1], 128, FFABS(outpicref->linesize[1]));
+            memset(outpicref->data[2] + i * outpicref->linesize[2], 128, FFABS(outpicref->linesize[2]));
+        }
     }
 
     if (showspectrum->xpos >= outlink->w)
-- 
1.7.11.2