height = 240
width = 320

out, _ = (
ffmpeg
.input('in.mp4')
.output('pipe:', format='rawvideo', pix_fmt='rgb24')
.run(capture_stdout=True)
)

send = (
ffmpeg
.input('pipe:', format='rawvideo', pix_fmt='rgb24')
.output('rtsp://10.0.0.37:3333')
.run_async(pipe_stdin=True)
)

video = (
np
.frombuffer(out, np.uint8)
.reshape([-1, height, width, 3])
)

send.stdin.write(video[0].tobytes())