Error: unable to open camera (openCV 4.5.4 version]

I tried to open simple_camera.py using $ python3 simple_camera.py code through terminal but following error occurs
“Unable to open camera”
My camera version is IMX. 219.-160, and it actually works when I try to operate it simply.
I think the problem is camera can’t recognize my python file. How should I solve this problem
code is as follows

MIT License

Copyright (c) 2019-2022 JetsonHacks

Using a CSI camera (such as the Raspberry Pi Version 2) connected to a

NVIDIA Jetson Nano Developer Kit using OpenCV

Drivers for the camera and OpenCV are included in the base image

import cv2

“”"
gstreamer_pipeline returns a GStreamer pipeline for capturing from the CSI camera
Flip the image by setting the flip_method (most common values: 0 and 2)
display_width and display_height determine the size of each camera pane in the window on the screen
Default 1920x1080 displayd in a 1/4 size window
“”"

def gstreamer_pipeline(
sensor_id=0,
capture_width=1920,
capture_height=1080,
display_width=960,
display_height=540,
framerate=30,
flip_method=0,
):
return (
“nvarguscamerasrc sensor-id=%d !”
"video/x-raw(memory:NVMM), width=(int)%d, height=(int)%d, 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”
% (
sensor_id,
capture_width,
capture_height,
framerate,
flip_method,
display_width,
display_height,
)
)

def show_camera():
window_title = “CSI Camera”

# To flip the image, modify the flip_method parameter (0 and 2 are the most common)
print(gstreamer_pipeline(flip_method=0))
video_capture = cv2.VideoCapture(gstreamer_pipeline(flip_method=0), cv2.CAP_GSTREAMER)
if video_capture.isOpened():
    try:
        window_handle = cv2.namedWindow(window_title, cv2.WINDOW_AUTOSIZE)
        while True:
            ret_val, frame = video_capture.read()
            # Check to see if the user closed the window
            # Under GTK+ (Jetson Default), WND_PROP_VISIBLE does not work correctly. Under Qt it does
            # GTK - Substitute WND_PROP_AUTOSIZE to detect if window has been closed by user
            if cv2.getWindowProperty(window_title, cv2.WND_PROP_AUTOSIZE) >= 0:
                cv2.imshow(window_title, frame)
            else:
                break 
            keyCode = cv2.waitKey(10) & 0xFF
            # Stop the program on the ESC key or 'q'
            if keyCode == 27 or keyCode == ord('q'):
                break
    finally:
        video_capture.release()
        cv2.destroyAllWindows()
else:
    print("Error: Unable to open camera")

if name == “main”:
show_camera()

Any error message?

Yes. it says “unable to open camera” with no additional comments

1 Like

Check with below command.

gst-launch-1.0 nvarguscamerasrc ! 'video/x-raw(memory:NVMM),width=1920,height=1080,format=NV12' ! nvvidconv ! fpsdisplaysink video-sink=fakesink --verbose

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