@@ -346,6 +346,8 @@ static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {

             avio_skip(pb, 0x30); // payload description

             fps = fps_umf2avr(avio_rl32(pb));

             if (!main_timebase.num || !main_timebase.den) {

+                av_log(s, AV_LOG_WARNING, "No FPS track tag, using UMF fps tag."

+                                          " This might give wrong results.\n");

                 // this may not always be correct, but simply the best we can get

                 main_timebase.num = fps.den;

                 main_timebase.den = fps.num * 2;