Why are the following errors emerging while using USB cam in Jetson nano 4Gb

Autonomous Machines Jetson & Embedded Systems Jetson Nano
,
1

My code :

import cv2
print(cv2.__version__)
dispW =1280
dispH =960
flip =2
#camSet='nvarguscamerasrc !  video/x-raw(memory:NVMM), width=3264, height=2464, format=NV12, framerate=21/1 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(dispW)+', height='+str(dispH)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink'
#cam = cv2.VideoCapture(camset) for raspberry pi camera
cam = cv2.VideoCapture('/dev/video0')
while True:
    ret, frame = cam.read()
    cv2.imshow('picam',frame)
    cv2.moveWindow('picam',0,0)
    if cv2.waitKey(1)==ord('q'):
        break

cam.release()
cv2.destroyAllWindows()

cv2 version: 4.1.1

Jetpack version :4.6

I am able to get the frame with no error, but the following warnings keep on emerging every time
[ WARN:0] global /home/nvidia/host/build_opencv/nv_opencv/modules/videoio/src/cap_gstreamer.cpp (1757) handleMessage OpenCV | GStreamer warning: Embedded video playback halted; module source reported: Could not read from resource.
[ WARN:0] global /home/nvidia/host/build_opencv/nv_opencv/modules/videoio/src/cap_gstreamer.cpp (886) open OpenCV | GStreamer warning: unable to start pipeline
[ WARN:0] global /home/nvidia/host/build_opencv/nv_opencv/modules/videoio/src/cap_gstreamer.cpp (480) isPipelinePlaying OpenCV | GStreamer warning: GStreamer: pipeline have not been created

3

Hi,
Please refer to
https://www.e-consystems.com/blog/camera/how-to-access-cameras-using-opencv-with-python/

Without putting gstreamer command, it should be called like

cap = cv2.VideoCapture(0)