cap.set(cv2.CAP_PROP_FORMAT,-1) always returns false

Python
1

Hi All:
I’m using opencv_python and here is my code:

import cv2
import numpy as np

def gstreamer_pipeline(
    capture_width=1280,
    capture_height=720,
    display_width=1280,
    display_height=720,
    framerate=15,
    flip_method=0,
):
    return (
        "nvarguscamerasrc ! "
        "video/x-raw(memory:NVMM), "
        "width=(int)%d, height=(int)%d, "
        "format=(string)NV12, framerate=(fraction)%d/1 ! "
        "nvvidconv flip-method=%d ! "
        "video/x-raw, width=(int)%d, height=(int)%d, format=(string)BGRx ! "
        "videoconvert ! "
        "video/x-raw, format=(string)BGR ! appsink"
        % (
            capture_width,
            capture_height,
            framerate,
            flip_method,
            display_width,
            display_height,
        )
    )

def show_camera():
    cap = cv2.VideoCapture(gstreamer_pipeline(flip_method=0), cv2.CAP_GSTREAMER)

    ret = cap.set(cv2.CAP_PROP_FORMAT,-1)
    print("ret : ",ret)

    if cap.isOpened():
        window_handle = cv2.namedWindow("CSI Camera", cv2.WINDOW_AUTOSIZE)
        while cv2.getWindowProperty("CSI Camera", 0) >= 0:
            ret_val, img = cap.read()

            cv2.imshow("CSI Camera", img)
            keyCode = cv2.waitKey(30) & 0xFF
            if keyCode == 27:
                break
        cap.release()
        cv2.destroyAllWindows()
    else:
        print("Unable to open camera")
if __name__ == "__main__":
    show_camera()

ret is always return false.
Do you have any suggestions can provide our reference,
Thanks in advance.

2

what do you expect to happen here ?