python视频帧提取并保存

opencv遇到的问题：

原代码中读取每帧图片的代码行为：

frame = video.read()

报错如下：

cv2.imencode('.jpg', frame)[1].tofile(img_file)

TypeError: Expected Ptr for argument '%s'

将其改为：

flag, frame = video.read()

运行正常。

文件存储的形式

代码如下：import cv2

import os

import json

def get_frame(video_path):

res = []

for each in os.listdir(video_path):

new_path = os.path.join(video_path, each)

video = cv2.VideoCapture(new_path)

img_path = './img' + '/' + str(each.split('.')[0])

if not os.path.exists(img_path):

os.mkdir(img_path)

os.chdir(img_path) #改变当前工作目录至图片保存文件夹

img_num = int(video.get(cv2.CAP_PROP_FRAME_COUNT))

video_fps = video.get(cv2.CAP_PROP_FPS)

video_size = (int(video.get(cv2.CAP_PROP_FRAME_WIDTH)),

int(video.get(cv2.CAP_PROP_FRAME_HEIGHT)))

video_message = {'name': each, 'fps': video_fps, 'size': video_size, 'nums': img_num}

res.append(video_message)

for i in range(img_num):

flag, frame = video.read()

img_file = '0000' + str(i) + '.jpg'

print(img_file)

cv2.imencode('.jpg', frame)[1].tofile(img_file)

video.release()

os.chdir(os.path.dirname(os.path.abspath(__file__)))# 返回代码工作目录

with open('data.json', 'w') as f:

json.dump(res, f)

if __name__ == '__main__':

videoPath = "./video"

get_frame(videoPath)