Demuxer rawvideo [raw video]:
    Common extensions: yuv,cif,qcif,rgb.
rawvideo demuxer AVOptions:
  -video_size        <image_size> .D....... set frame size
  -pixel_format      <string>     .D....... set pixel format (default "yuv420p")
  -framerate         <video_rate> .D....... set frame rate (default "25")


