// Do you want audio and video to "clock" themselves. When they are clocked then
// by adding video frames, they will be rate limited to match the current frame-rate
// that you are submitting at. The same is true for audio. In general if you are submitting
// video and audio off a single thread then you should only clock one of them (video is
//probably the better of the two to clock off). If you are submtiting audio and video
// of separate threads then having both clocked can be useful.
public bool clock_video, clock_audio;