Getting Camera List and Resolution in Python on Windows
OpenCV does not have an API for enumerating capture devices. The sample shows how to create a Python extension to invoke DirectShow C++ APIs for enumerating capture devices and corresponding resolutions.
Environment
- Microsoft Windows SDK
- Python 3.6 or later
How to Build the CPython Extension
-
Create a source distribution:
python setup.py sdist
-
distutils:
python .\setup_distutils.py build -
scikit-build:
pip wheel . --verbose
Test
import device
import cv2
def select_camera(last_index):
number = 0
hint = "Select a camera (0 to " + str(last_index) + "): "
try:
number = int(input(hint))
# select = int(select)
except Exception:
print("It's not a number!")
return select_camera(last_index)
if number > last_index:
print("Invalid number! Retry!")
return select_camera(last_index)
return number
def open_camera(index):
cap = cv2.VideoCapture(index)
return cap
def main():
# print OpenCV version
print("OpenCV version: " + cv2.__version__)
# Get camera list
device_list = device.getDeviceList()
index = 0
for camera in device_list:
print(str(index) + ': ' + camera[0] + ' ' + str(camera[1]))
index += 1
last_index = index - 1
if last_index < 0:
print("No device is connected")
return
# Select a camera
camera_number = select_camera(last_index)
# Open camera
cap = open_camera(camera_number)
if cap.isOpened():
width = cap.get(3) # Frame Width
height = cap.get(4) # Frame Height
print('Default width: ' + str(width) + ', height: ' + str(height))
while True:
ret, frame = cap.read()
cv2.imshow("frame", frame)
# key: 'ESC'
key = cv2.waitKey(20)
if key == 27:
break
cap.release()
cv2.destroyAllWindows()
if __name__ == "__main__":
main()python test.py
