[FFmpeg-cvslog] lavfi/showwaves: fix crash in case of negative linesize

[Paul B Mahol]

ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Mon Apr 29 13:36:59 2013 +0000| [c645659988af1208e83ba4a8a708bb7ea31d0f41] | committer: Paul B Mahol

lavfi/showwaves: fix crash in case of negative linesize

Signed-off-by: Paul B Mahol <onemda at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c645659988af1208e83ba4a8a708bb7ea31d0f41
---

 libavfilter/avf_showwaves.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavfilter/avf_showwaves.c b/libavfilter/avf_showwaves.c
index 5e89146..e9d3062 100644
--- a/libavfilter/avf_showwaves.c
+++ b/libavfilter/avf_showwaves.c
@@ -188,7 +188,8 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
                                           (AVRational){ 1, inlink->sample_rate },
                                           outlink->time_base);
             linesize = outpicref->linesize[0];
-            memset(outpicref->data[0], 0, showwaves->h*linesize);
+            for (j = 0; j < outlink->h; j++)
+                memset(outpicref->data[0] + j * linesize, 0, outlink->w);
         }
         for (j = 0; j < nb_channels; j++) {
             h = showwaves->h/2 - av_rescale(*p++, showwaves->h/2, MAX_INT16);