实时显示摄像头图像
按下空格键，截取图片
按下tab键，开始录制摄像内容，再次按下，结束录制 

按下Esc键，关闭窗口

import cv2
import numpy

#第几章图片
img_count=0


InitVideo=False
#第几个视频
video_count=0
video_flag=False

#参数为0，表示打开笔记本的内置摄像头
cameraCapture = cv2.VideoCapture(0)

w = cameraCapture.get(cv2.CAP_PROP_FRAME_WIDTH)
# 获取视频帧的高
h = cameraCapture.get(cv2.CAP_PROP_FRAME_HEIGHT)
# 获取视频帧的帧率
fps = cameraCapture.get(cv2.CAP_PROP_FPS)
# 获取视频流的总帧数
fcount = cameraCapture.get(cv2.CAP_PROP_FRAME_COUNT)

# 给窗口命名
cv2.namedWindow('MyWindow')

# 按帧读取数据
success, frame = cameraCapture.read()

while success :
    #镜像显示摄像头图像
    mirroredFrame=numpy.fliplr(frame).copy()
    cv2.imshow('MyWindow', mirroredFrame)

    keycode=cv2.waitKey(1)

    if keycode == 32:
        cv2.imwrite('img'+str(img_count)+'.jpg', frame)
        img_count=img_count+1
    elif keycode == 27:
        break
    elif keycode == 9:
        video_flag =not video_flag #这个参数控制是否开始录屏
        InitVideo = True    #这个参数来影响初始化视频的次数
    #关于录屏
    if video_flag == True:
        if InitVideo == True:
            # 初始化
            writer = cv2.VideoWriter('out' + str(video_count) + '.avi', cv2.VideoWriter_fourcc('X', 'V', 'I', 'D'),
                                     int(fps), (int(w), int(h)))
            video_count = video_count + 1
            InitVideo =False
        writer.write(frame)

    success, frame = cameraCapture.read()
cv2.destroyWindow('MyWindow')
cameraCapture.release()
writer.release()
cv2.destroyAllWindows()

截图：