OpenH264 is only used with WebRTC video call.. And is a software only decoder/encoder... There shouldn't be much difference for h264 videos between Safari and

OpenH264 is only used with WebRTC video call.. And is a software only decoder/encoder... There shouldn't be much difference for h264 videos between Safari and Firefox, except in Full Screen. For full screen, Safari uses the OS to render the images and can have a very efficient code path. Firefox doesn't support it at all (for now)