问不保存在opencv中的写入和读取视频

EN

video =  cv2.VideoWriter('using.mp4', cv2.VideoWriter_fourcc(*'MJPG'), 10, size)
for frame in frames:
    writer.write(frame)
for frame in frames:
    # do other stuff here

import cv2


def cam_test(port: int = 0) -> None:
    frames = []
    cap = cv2.VideoCapture(port)
    if not cap.isOpened():  # Check if the web cam is opened correctly
        print("failed to open cam")
    else:
        print('cam opened on port {}'.format(port))

        for i in range(10 ** 10):
            success, cv_frame = cap.read()
            if not success:
                print('failed to capture frame on iter {}'.format(i))
                break
            frames.append(cv_frame)
            cv2.imshow('Input', cv_frame)
            k = cv2.waitKey(1)
            if k == ord('q'):
                break

        cap.release()
        cv2.destroyAllWindows()

    # Now you have the frames at hand

    if len(frames) > 0:
        # if you want to write them
        size = (frames[0].shape[1], frames[0].shape[0])
        video = cv2.VideoWriter(
            filename='using.mp4',
            fourcc=cv2.VideoWriter_fourcc(c1='m', c2='p', c3='4', c4='v'),
            fps=10,
            frameSize=size
        )
        for frame in frames:
            video.write(frame)

        # and to answer your question, you wanted to do video.read() which would have gave you frame by frame
        for frame in frames:
            pass  # each iteration is like video.read() if video.read() was possible

    return


if __name__ == '__main__':
    cam_test()