diff --git a/etc/codecs.conf b/etc/codecs.conf
index 3b7f20ba4f..735e333f2c 100644
--- a/etc/codecs.conf
+++ b/etc/codecs.conf
@@ -1572,6 +1572,7 @@ videocodec ffsmkvid
   driver ffmpeg
   dll "smackvid"
 
+; only works with libavformat right now
 videocodec ffcavs
   info "Chinese AVS Video"
   status working