flvdemux: be careful with negative cts

Fixes #661477.

diff --git a/gst/flv/gstflvdemux.c b/gst/flv/gstflvdemux.c
index 7432520..8aa352e 100644 (file)
--- a/gst/flv/gstflvdemux.c
+++ b/gst/flv/gstflvdemux.c
@@ -1195,7 +1195,9 @@ gst_flv_demux_parse_tag_video (GstFlvDemux * demux, GstBuffer * buffer)
 
     GST_LOG_OBJECT (demux, "got cts %d", cts);
 
-    pts = pts + cts;
+    /* avoid negative overflow */
+    if (cts >= 0 || pts >= -cts)
+      pts += cts;
   }
 
   GST_LOG_OBJECT (demux, "video tag with codec tag %u, keyframe (%d) "