Capture a video stream coming from an rtsp camera and write it to a file

[gbetsos]

I am trying to capture a video stream coming from an rtsp camera and write it to a file. Using Jetson Xavier AGX with Jetpack 4.5 [L4T 32.5.0]

I am using below python app to perform the task:

	cap = cv2.VideoCapture("rtspsrc location=rtsp://10.34.134.1/Streaming/channels/1/ user-id=myuser user-pw=mypass !  rtph264depay ! h264parse ! nvv4l2decoder ! nvvidconv ! video/x-raw, format=BGRx ! videoconvert ! video/x-raw,format=BGR ! appsink")


    w = cap.get(cv2.CAP_PROP_FRAME_WIDTH)
    h = cap.get(cv2.CAP_PROP_FRAME_HEIGHT)
    fps = cap.get(cv2.CAP_PROP_FPS)
    print('Src opened, %dx%d @ %d fps' % (w, h, fps))

    gst_out = "appsrc ! video/x-raw, format=BGR ! queue ! videoconvert ! video/x-raw,format=BGRx ! nvvidconv ! nvv4l2h264enc ! h264parse ! matroskamux ! filesink location=test.mkv "
    out = cv2.VideoWriter(gst_out, cv2.CAP_GSTREAMER, 0, float(fps), (int(w), int(h)))
    if not out.isOpened():
        print("Failed to open output")
        exit()

    if cap.isOpened():
        while True:
            ret_val, img = cap.read()
            if not ret_val:
                break;
            out.write(img);
            cv2.waitKey(1)
    else:
        print ("pipeline open failed")

    print("successfully exit")
    cap.release()
    out.release()

Opening the stream doesn’t work. I get the error below:

[ERROR:0@0.041] global /io/opencv/modules/videoio/src/cap.cpp (164) open VIDEOIO(CV_IMAGES): raised OpenCV exception:

OpenCV(4.6.0) /io/opencv/modules/videoio/src/cap_images.cpp:253: error: (-5:Bad argument) CAP_IMAGES: can’t find starting number (in the name of file): rtspsrc location=rtsp://10.34.134.1/Streaming/channels/1/ user-id=myuser user-pw=mypass ! rtph264depay ! h264parse ! nvv4l2decoder ! nvvidconv ! video/x-raw, format=BGRx ! videoconvert ! video/x-raw,format=BGR ! appsink in function ‘icvExtractPattern’

Can I somehow modify the string supplied to cv2.VideoCapture in order to properly read the rtsp stream?

[DaneLLL]

Hi,
The error shows the OpenCV stack does not enable gstreamer. Please try with default OpenCV package installed through SDKManager.

Or you may try to re-build it by using this script:
GitHub - mdegans/nano_build_opencv: Build OpenCV on Nvidia Jetson Nano