OpenCV is able to read the stream but VLC not

Question

I'm trying to stream my webcam frames to an UDP address. Here is my sender code.

cmd = ['ffmpeg', '-y', '-f', 'rawvideo', '-pixel_format', 'bgr24', '-video_size', f'{width}x{height}', 
       '-i', '-', '-c:v', 'mpeg4','-preset', 'ultrafast', '-tune', 'zerolatency','-b:v', '1.5M',
       '-f', 'mpegts', f'udp://@{ip_address}:{port}']
p = subprocess.Popen(cmd, stdin=subprocess.PIPE)
camera = cv2.VideoCapture(0)
while True:
    ret, frame = camera.read()
    cv2.imshow("Sender",frame)
    if not ret:
        break
    p.stdin.write(frame.tobytes())
    p.stdin.flush()
    if cv2.waitKey(1) & 0xFF == ord('q'):
            break

This Python code can make stream successfully. I can read the stream with this receiver code.

q = queue.Queue()
def receive():
    cap = cv2.VideoCapture('udp://@xxx.x.xxx.xxx:5000')
    ret, frame = cap.read()
    q.put(frame)
    while ret:
        ret, frame = cap.read()
        q.put(frame)
def display():
    while True:
        if q.empty() != True:
            frame = q.get()
            cv2.imshow('Receiver', frame)
        k = cv2.waitKey(1) & 0xff
        if k == 27:  # press 'ESC' to quit
            break
tr = threading.Thread(target=receive, daemon=True)
td = threading.Thread(target=display)
tr.start()
td.start()
td.join()

But I can not watch the stream from VLC. I'm going to Media->Open Network Stream-> udp://@xxx.x.xxx.xxx:5000 to watch stream. After some seconds, the timer that located bottom left of VLC starts to increase but there are no frames in screen, just VLC icon.

I checked firewall rules, opened all ports to UDP connections. I am using my IP address to send frames and watch them. Also, I tried other video codecs like h264, hvec, mpeg4, rawvideo. Additionally, I tried to watch stream by using Windows Media Player but it didn't work.

What should I do to fix this issue?

Answer 1

I tried to view stream from mpv and it worked, I think this issue is about a bug of VLC