ffmpeg python video from images

1def read_frame_as_jpg(in_filename, frame_num):
2    out, err = (
3        ffmpeg
4        .input(in_filename)
5        .filter_('select', 'gte(n,{})'.format(frame_num))
6        .output('pipe:', vframes=1, format='image2', vcodec='mjpeg')
7        .run(capture_stdout=True)
8    )
9    return out