[FFmpeg-cvslog] avfilter/vf_w3fdif: Fix segfault on allocation error

[Andreas Rheinhardt]

ffmpeg | branch: release/4.4 | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Wed Oct  6 15:20:30 2021 +0200| [b229dce2e4c2db9f52808978a114e711f38aa75c] | committer: Andreas Rheinhardt

avfilter/vf_w3fdif: Fix segfault on allocation error

Reviewed-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
(cherry picked from commit cd1aaec760273bd7673b27609f114599e2d9b5a9)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=b229dce2e4c2db9f52808978a114e711f38aa75c
---

 libavfilter/vf_w3fdif.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/libavfilter/vf_w3fdif.c b/libavfilter/vf_w3fdif.c
index 1a64b2b953..d380fdd4de 100644
--- a/libavfilter/vf_w3fdif.c
+++ b/libavfilter/vf_w3fdif.c
@@ -283,7 +283,7 @@ static int config_input(AVFilterLink *inlink)
     AVFilterContext *ctx = inlink->dst;
     W3FDIFContext *s = ctx->priv;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
-    int ret, i, depth;
+    int ret, i, depth, nb_threads;
 
     if ((ret = av_image_fill_linesizes(s->linesize, inlink->format, inlink->w)) < 0)
         return ret;
@@ -297,10 +297,11 @@ static int config_input(AVFilterLink *inlink)
     }
 
     s->nb_planes = av_pix_fmt_count_planes(inlink->format);
-    s->nb_threads = ff_filter_get_nb_threads(ctx);
-    s->work_line = av_calloc(s->nb_threads, sizeof(*s->work_line));
+    nb_threads = ff_filter_get_nb_threads(ctx);
+    s->work_line = av_calloc(nb_threads, sizeof(*s->work_line));
     if (!s->work_line)
         return AVERROR(ENOMEM);
+    s->nb_threads = nb_threads;
 
     for (i = 0; i < s->nb_threads; i++) {
         s->work_line[i] = av_calloc(FFALIGN(s->linesize[0], 32), sizeof(*s->work_line[0]));