TelloPY: no existing PPS reference

[treehousedrone]

Tried tellopy.example.video-effects after installing tellopy, opencv-python, images and pyav successfully on ubuntu 18.04. No video was display and the following messages are observed. Please advise.

Tello: 14:29:24.865: Info: start video thread
Tello: 14:29:24.865: Info: send connection request (cmd="conn_req:9617")
Tello: 14:29:24.865: Info: state transit State::disconnected -> State::connecting
Tello: 14:29:24.865: Info: video receive buffer size = 425984
Tello: 14:29:24.890: Info: connected. (port=9617)
Tello: 14:29:24.890: Info: send_time (cmd=0x46 seq=0x01e4)
Tello: 14:29:24.890: Info: state transit State::connecting -> State::connected
Tello: 14:29:24.890: Info: get video stream
Tello: 14:29:24.890: Info: start video (cmd=0x25 seq=0x01e4)
Tello: 14:29:24.941: Info: recv: ack: cmd=0x34 seq=0x0000 cc 60 00 27 90 34 00 00 00 00 72 a5
Tello: 14:29:24.942: Info: recv: ack: cmd=0x20 seq=0x0000 cc 60 00 27 b0 20 00 00 00 00 42 b9
Tello: 14:29:24.942: Info: recv: ack: cmd=0x34 seq=0x0000 cc 60 00 27 90 34 00 00 00 00 72 a5
Tello: 14:29:24.943: Info: recv: ack: cmd=0x20 seq=0x0000 cc 60 00 27 b0 20 00 00 00 00 42 b9
Tello: 14:29:27.869: Info: video data 1014225 bytes 494.9KB/sec
non-existing PPS 0 referenced
non-existing PPS 0 referenced
decode_slice_header error
no frame!
non-existing PPS 0 referenced
non-existing PPS 0 referenced
decode_slice_header error
no frame!

 

[nagainamae]

you can try multi threading and wait a minute.

def recv_thread():
    global frameA
    global run_recv_thread
    global drone
    print('start recv_thread()')
    drone = tellopy.Tello()
    drone.connect()
    drone.subscribe(drone.EVENT_FLIGHT_DATA, handler)
    drone.set_video_encoder_rate(1)
    drone.set_loglevel(drone.LOG_WARN)
    container = av.open(drone.get_video_stream())
    while run_recv_thread:
        for f in container.decode(video=0):
            frameA = f
        time.sleep(0.01)

...

threading.Thread(target=recv_thread).start()
...
while run_cv_thread:
    if frameA is None:
        time.sleep(0.01)
    else:
        #do your opencv stuff with frameA