[FFmpeg-cvslog] lavfi/af_pan: fix sign handling in channel coefficient parser

[Michael Roitzsch]

ffmpeg | branch: release/3.4 | Michael Roitzsch <reactorcontrol at icloud.com> | Sat Nov 18 13:33:08 2017 +0100| [752659ff1e0f6d9de93321f8b7e7c4ff741d0c8e] | committer: Tobias Rapp

lavfi/af_pan: fix sign handling in channel coefficient parser

When a channel formula ends with a subtraction, the next formula will
otherwise have its first coefficient negated.

(cherry picked from commit 4f4e19914ddca5096bf7639c7c99a9045e436e8b)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=752659ff1e0f6d9de93321f8b7e7c4ff741d0c8e
---

 libavfilter/af_pan.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libavfilter/af_pan.c b/libavfilter/af_pan.c
index 23b29419b6..d8a63a7952 100644
--- a/libavfilter/af_pan.c
+++ b/libavfilter/af_pan.c
@@ -166,6 +166,7 @@ static av_cold int init(AVFilterContext *ctx)
             goto fail;
         }
         /* gains */
+        sign = 1;
         while (1) {
             gain = 1;
             if (sscanf(arg, "%lf%n *%n", &gain, &len, &len))