[Python] How can I record a video with MJPG instead of YUYV on a raspberry PI 4b with...

Good day to you dear developers from stackoverflow. I am currently recording live-video with my usb webcam on my raspberry Pi with the following code:

import cv2 as cv
import time

class CameraInst():
# Constructor...
def __init__(self):

cap = cv.VideoCapture(0) # Capture Video...

cap.set(cv.CAP_PROP_FOURCC, cv.VideoWriter_fourcc('M','J','P','G'))

cap.set(cv.CAP_PROP_FPS, 15)

cap.set(cv.CAP_PROP_FRAME_WIDTH, 1920)

cap.set(cv.CAP_PROP_FRAME_HEIGHT, 1080)


self.cap=cap

print("Aufnahme wird vorbereitet")
time.sleep(1)

def captureVideo(self):
# Capture
ret, self.frame = self.cap.read()
cv.moveWindow('frame',0,0)
cv.imshow('frame',self.frame)



def main():
cam1 = CameraInst()

while(True):
# Display the resulting frames...
cam1.captureVideo() # Live stream of video on screen...
if cv.waitKey(1) & 0xFF == ord('q'):
break

if __name__=='__main__':
main()




The code doesn't work anymore, when I use the cap.set(cv.CAP_PROP_FPS, 15) function and I don't know what I've done wrong.

I get the following errors:

[ WARN:0] global ../modules/videoio/src/cap_gstreamer.cpp (961) open OpenCV | GStreamer warning: Cannot query video position: status=0, value=-1, duration=-1
[ WARN:0] global ../modules/videoio/src/cap_gstreamer.cpp (1214) setProperty OpenCV | GStreamer warning: GStreamer: unhandled property
[ WARN:0] global ../modules/videoio/src/cap_gstreamer.cpp (1824) handleMessage OpenCV | GStreamer warning: Embedded video playback halted; module v4l2src0 reported: Internal data stream error.
[ WARN:0] global ../modules/videoio/src/cap_gstreamer.cpp (536) startPipeline OpenCV | GStreamer warning: unable to start pipeline
[ WARN:0] global ../modules/videoio/src/cap_gstreamer.cpp (1085) setProperty OpenCV | GStreamer warning: no pipeline
[ WARN:0] global ../modules/videoio/src/cap_gstreamer.cpp (1085) setProperty OpenCV | GStreamer warning: no pipeline
Aufnahme wird vorbereitet
Traceback (most recent call last):
File "/home/pi/Documents/RPV_Video_V8.py", line 45, in <module>
main()
File "/home/pi/Documents/RPV_Video_V8.py", line 40, in main
cam1.captureVideo() # Live stream of video on screen...
File "/home/pi/Documents/RPV_Video_V8.py", line 31, in captureVideo
cv.imshow('frame',self.frame)
cv2.error: OpenCV(4.5.1) ../modules/highgui/src/window.cpp:376: error: (-215:Assertion failed) size.width>0 && size.height>0 in function 'imshow'



Not the thing is, if I remove the cap.set(cv.CAP_PROP_FPS, 15) then the code works fine, but then the camera record with YUYV and not MJPG.

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