I have built my own opencv python package from source.

import cv2
print(cv2.__version__)

prints: 3.4.5

Now the issue I am facing is regarding the use of gstreamer from the VideoCapture class of opencv. I am trying to get this mimimum working example running on python3

cap = cv2.VideoCapture("videotestsrc ! appsink")if not cap.isOpened():print("Cannot capture test src. Exiting.")quit()while True:ret, frame = cap.read()if ret == False:breakcv2.imshow("CVtest",frame)if cv2.waitKey(1) & 0xFF == ord('q'):break

Capture fails, producing my print above (see if statement). I checked:

import cv2
print(cv2.getBuildInformation())

prints:

Video I/O:
DC1394:                      NO
FFMPEG:                      NOavcodec:                   NOavformat:                  NOavutil:                    NOswscale:                   NOavresample:                NO
GStreamer:                   NO
libv4l/libv4l2:              NO
v4l/v4l2:                    linux/videodev2.h

Seeing that, it made absolute sense that my gstreamer pipeline didn't work. I ensured WITH_GSTREAMER was set to ON during ccmake of OpenCV (which it already was). Still the issue maintained. I even tried setting WITH_GSTREAMER_0_10 to ON as well. Still no luck having gstreamer enabled from the cv2 python module.

Before anyone suggests using pip3 to install cv2. I tried that, too. The issue with getting the package from pip is, it doesn't let you configure gstreamer support at all.

Can anyone provide help here?

For those who are struggling with the same problem on Windows... I had to set following CMake Options:

1. only set "WITH_GSTREAMER" option to True, "WITH_GSTREAMER_0_10" MUST BE FALSE
2. add new entry "GSTREAMER_DIR"=(path to gstreamer)for me it was "C:/gstreamer/1.0/x86_64" I found this solution here

My OpenCV version: 3.4.3