royshil/opencv_capture_v4l2.py

## opencv_capture_v4l2.py
#!/usr/bin/env python

import numpy as np
import cv2
import os
import v4l2capture
import select

if __name__ == '__main__':
    #cap = cv2.VideoCapture(0)
    #cap.set(cv2.cv.CV_CAP_PROP_FRAME_WIDTH, 1920)      # <-- this doesn't work. OpenCV tries to set VIDIO_S_CROP instead of the frame format
    #cap.set(cv2.cv.CV_CAP_PROP_FRAME_HEIGHT, 1080)

    # The following is from: https://github.com/gebart/python-v4l2capture

    # Open the video device.
    video = v4l2capture.Video_device("/dev/video0")

    # Suggest an image size to the device. The device may choose and
    # return another size if it doesn't support the suggested one.
    size_x, size_y = video.set_format(1920, 1080, fourcc='MJPG')

    print "device chose {0}x{1} res".format(size_x, size_y)

    # Create a buffer to store image data in. This must be done before
    # calling 'start' if v4l2capture is compiled with libv4l2. Otherwise
    # raises IOError.
    video.create_buffers(30)

    # Send the buffer to the device. Some devices require this to be done
    # before calling 'start'.
    video.queue_all_buffers()

    # Start the device. This lights the LED if it's a camera that has one.
    print "start capture"
    video.start()

    while(True):
        #We used to do the following, but it doesn't work :(
        #ret, frame = cap.read()

        #Instead...

        # Wait for the device to fill the buffer.
        select.select((video,), (), ())

        # The rest is easy :-)
        image_data = video.read_and_queue()

        print "decode"
        frame = cv2.imdecode(np.frombuffer(image_data, dtype=np.uint8), cv2.cv.CV_LOAD_IMAGE_COLOR)


        cv2.imshow('frame', frame)
        key = cv2.waitKey(1)
        if key & 0xFF == ord('q'):
            break

    #cap.release()
    video.close()

    cv2.destroyAllWindows()
	#!/usr/bin/env python

	import numpy as np
	import cv2
	import os
	import v4l2capture
	import select

	if __name__ == '__main__':
	#cap = cv2.VideoCapture(0)
	#cap.set(cv2.cv.CV_CAP_PROP_FRAME_WIDTH, 1920) # <-- this doesn't work. OpenCV tries to set VIDIO_S_CROP instead of the frame format
	#cap.set(cv2.cv.CV_CAP_PROP_FRAME_HEIGHT, 1080)

	# The following is from: https://github.com/gebart/python-v4l2capture

	# Open the video device.
	video = v4l2capture.Video_device("/dev/video0")

	# Suggest an image size to the device. The device may choose and
	# return another size if it doesn't support the suggested one.
	size_x, size_y = video.set_format(1920, 1080, fourcc='MJPG')

	print "device chose {0}x{1} res".format(size_x, size_y)

	# Create a buffer to store image data in. This must be done before
	# calling 'start' if v4l2capture is compiled with libv4l2. Otherwise
	# raises IOError.
	video.create_buffers(30)

	# Send the buffer to the device. Some devices require this to be done
	# before calling 'start'.
	video.queue_all_buffers()

	# Start the device. This lights the LED if it's a camera that has one.
	print "start capture"
	video.start()

	while(True):
	#We used to do the following, but it doesn't work :(
	#ret, frame = cap.read()

	#Instead...

	# Wait for the device to fill the buffer.
	select.select((video,), (), ())

	# The rest is easy :-)
	image_data = video.read_and_queue()

	print "decode"
	frame = cv2.imdecode(np.frombuffer(image_data, dtype=np.uint8), cv2.cv.CV_LOAD_IMAGE_COLOR)


	cv2.imshow('frame', frame)
	key = cv2.waitKey(1)
	if key & 0xFF == ord('q'):
	break

	#cap.release()
	video.close()

	cv2.destroyAllWindows()