OpenCV 调用摄像头并进行视频抽帧

最近在学习opencv时用到将视频抽帧的问题。用opencv模块可以很方便的做一些跟视频图像分析的研究。下面我借鉴了opencv项目的开源代码改成了demo脚本。
github资源地址

# -*- coding:utf-8 -*-
'''
Simple Cam Test - BGR and Gray
    Create by pythonprogramming.net ==> See the tutorial here:
    https://pythonprogramming.net/loading-video-python-opencv-tutorial
Adapted by Marcelo Rovai - MJRoBot.org @8Feb18
'''

import numpy as np
import cv2
from hashlib import md5
import os

cap = cv2.VideoCapture(0)
cap.set(1, int(cap.get(7)/2)) #获取视频的中间帧

'''
在当前执行文件环境下，创建抽帧图片存储文件夹
'''
path='facetmp'
os.mkdir(path)

'''
从摄像头获取视频流
'''
while(True):
    ret, frame = cap.read()
    #print(ret,frame)
    frame = cv2.flip(frame, 1)
    #print(frame)
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    
    cv2.imshow('welcome', frame)
    cv2.imshow('Gray Windows', gray)
    filepath='facetmp/{}.{}'.format(md5(frame).hexdigest(),'jpg')
    cv2.imwrite(filepath, frame)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break
cap.release()
cv2.destroyAllWindows()

timg.jpg