print_fps        2834 libavformat/utils.c             print_fps(av_q2d(st->r_frame_rate), "tbr");
print_fps        2836 libavformat/utils.c             print_fps(1/av_q2d(st->time_base), "tbn");
print_fps        2838 libavformat/utils.c             print_fps(1/av_q2d(st->codec->time_base), "tbc");