Hello!
I tried to catch video from OV5640 via OpenCV at 1920x1080, but i have only 3 fps
My python code:
import cv2
import numpy as np
pipeline = 'v4l2src device=/dev/video0 ! video/x-raw, framerate=30/1,width=1920,height=1080 ! videoconvert ! appsink'
camera = cv2.VideoCapture(pipeline, cv2.CAP_GSTREAMER)
while True:
success, frame = camera.read()
if(success == True):
cv2.imshow("Image", frame)
if cv2.waitKey(1) == 27:
break
print(success)
cv2.destroyAllWindows()
camera.release()
If i print this comand in terminal capture works fine:
gst-launch-1.0 v4l2src device=/dev/video0 ! video/x-raw, framerate=30/1,width=1920,height=1080 ! videoconvert ! waylandsink
How to make opencv capture a picture via gstreamer at 30 fps?
And I also found an interesting fact that if you take an image through v4l2 then everything works fine (at 30 fps) but only in 640x480 resolution:
cv2.VideoCapture(0 cv2.CAP_V4L2)
If I try to change it this way:
camera.set(cv2.CAP_PROP_FRAME_WIDTH, 1920)
camera.set(cv2.CAP_PROP_FRAME_HEIGHT, 1080)
the program not work with the following message in debuger:
[ WARN:0] global /usr/src/debug/opencv/4.5.2.imx-r0/git/modules/videoio/src/cap_v4l.cpp (1001) tryIoctl VIDEOIO(V4L2:/dev/video0): select() timeout.
Resolution changed, but not work
Info from terminal via v4l2-ctl -d /dev/video0 --all:
Format Video Capture:
Width/Height : 1920/1080
Pixel Format : ''
Field : None
Bytes per Line : 0
Size Image : 4147200
Colorspace : Default
Transfer Function : Default (maps to Rec. 709)
YCbCr/HSV Encoding: Default (maps to ITU-R 601)
Quantization : Default (maps to Full Range)
And I also noticed that when I run this comand:
gst-launch-1.0 v4l2src device=/dev/video0 ! video/x-raw, framerate=30/1,width=640,height=480 ! waylandsink
it opens in full screen, i.e. resize to 1920x1080 and the image is displayed at 20-25 fps, if I resize through opencv then fps drops from 30 frames to 10-15
What do I need in the end.
1. Get 30 fps when reading 1920х1080 through opencv.
2. Get 640x480 30fps resize up to 1920x1080 via nxp and read it in opencv
Please help!
