From d1afd3e1d6e43f4d37ae147091f270124ac48e04 Mon Sep 17 00:00:00 2001
From: Vittorio Giovara <vittorio.giovara@gmail.com>
Date: Sat, 18 Oct 2014 16:10:35 +0100
Subject: [PATCH] vf_format: check input validity

CC: libav-stable@libav.org
---
 libavfilter/vf_format.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavfilter/vf_format.c b/libavfilter/vf_format.c
index d37f870537..914089deab 100644
--- a/libavfilter/vf_format.c
+++ b/libavfilter/vf_format.c
@@ -59,6 +59,11 @@ static av_cold int init(AVFilterContext *ctx)
     int nb_formats = 1;
     int i;
 
+    if (!s->pix_fmts) {
+        av_log(ctx, AV_LOG_ERROR, "Empty output format string.\n");
+        return AVERROR(EINVAL);
+    }
+
     /* count the formats */
     cur = s->pix_fmts;
     while ((cur = strchr(cur, '|'))) {