From 66fdbcbbc9d24e18c9faaa1f56bce85ccbb25e07 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20B=C5=93sch?= <clement.boesch@smartjog.com>
Date: Tue, 17 Jan 2012 11:01:37 +0100
Subject: [PATCH] pan: raise correct error when there is no param specified.

---
 libavfilter/af_pan.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavfilter/af_pan.c b/libavfilter/af_pan.c
index ca14eca533..a62dea19e7 100644
--- a/libavfilter/af_pan.c
+++ b/libavfilter/af_pan.c
@@ -95,6 +95,12 @@ static av_cold int init(AVFilterContext *ctx, const char *args0, void *opaque)
     int nb_in_channels[2] = { 0, 0 }; // number of unnamed and named input channels
     double gain;
 
+    if (!args0) {
+        av_log(ctx, AV_LOG_ERROR,
+               "pan filter needs a channel layout and a set "
+               "of channels definitions as parameter\n");
+        return AVERROR(EINVAL);
+    }
     if (!args)
         return AVERROR(ENOMEM);
     arg = av_strtok(args, ":", &tokenizer);