Use half GOP size in h264

Author: sergystepanov

pkg/encoder/h264/x264.go

@@ -91,6 +91,7 @@ func NewEncoder(w, h int, th int, opts *Options) (encoder *H264, err error) {
 	param.i_width = C.int(w)
 	param.i_height = C.int(h)
 	param.i_log_level = C.int(opts.LogLevel)
+	param.i_keyint_max = 120
 	param.i_sync_lookahead = 0
 	param.i_threads = C.int(th)
 	if th != 1 {