python opencv读取视频帧_关于opencv python 获取视频流的一帧

各位大佬:

1.我是在centos6.9系统编译的python3.6.3版本，地址是/usr/local/python3,然后使用bin文件下的pip3安装了opencv_python库

2.在/usr/local/python3/lib/python3.6/site-packages/下生成opencv_python-3.3.0.10.dist-info和cv2目录

3.然后使用命令运行/usr/local目录下的snapshot.py脚本文件，即:/usr/local/python3/bin/python3 snapshot.py 提示错误:

OpenCV Error: Unknown error code -10 (Raw image encoder error: Empty JPEG image (DNL not supported)) in throwOnEror, file /io/opencv/modules/imgcodecs/src/grfmt_base.cpp, line 140

Traceback (most recent call last):

File "snapshot.py", line 21, in <module>

main()

File "snapshot.py", line 11, in main

ret,arr = cv2.imencode('.jpg', frame)

cv2.error: /io/opencv/modules/imgcodecs/src/grfmt_base.cpp:140: error: (-10) Raw image encoder error: Empty JPEG image (DNL not supported) in function throwOnEror

请教大佬是什么原因，在windows下是可以按照程序截取到帧图片

import cv2

import numpy as np

from sys import argv

import base64

def main():

cap = cv2.VideoCapture("rtsp://184.72.239.149/vod/mp4://BigBuckBunny_175k.mov")

for i in range(1, 500):

ret,frame = cap.read()

ret,arr = cv2.imencode('.jpg', frame)

a = arr.tostring()

fp = open('test'+str(i)+'.jpg', 'wb')

fp.write(a)

fp.close()

fps = cap.get(5)

print(fps)

cap.release()

if __name__ == '__main__':

main()