We used MediaPlayer to do slow motion replay and run into the following problem: seek + setRate combination was always changing the rate of the file but it was rewinding to correct position only in 50% of invocations. For the rest of invocations it was either just playing from the beginning or from the current position.

Here is the code we're using:


       mp.setOnMarker(new EventHandler<MediaMarkerEvent>() {

            @Override
            public void handle(MediaMarkerEvent mme) {
                if (mme.getMarker().getKey().startsWith("Stop")) {
                    if (mp.getRate() == 1) {
                        mp.seek(media.getMarkers().get("Start" + mme.getMarker().getKey().substring(4)));
                        mp.setRate(0.5);
                    } else {
                        mp.pause();
                        scene.setRoot(bpListView);
                    }
            }
        });

Video file is H.264 video in mp4 format.