下面的脚本将提取帧每半秒的所有视频在文件夹。(适用于python 3.7)

import cv2
import os
listing = os.listdir(r'D:/Images/AllVideos')
count=1
for vid in listing:
    vid = r"D:/Images/AllVideos/"+vid
    vidcap = cv2.VideoCapture(vid)
    def getFrame(sec):
        vidcap.set(cv2.CAP_PROP_POS_MSEC,sec*1000)
        hasFrames,image = vidcap.read()
        if hasFrames:
            cv2.imwrite("D:/Images/Frames/image"+str(count)+".jpg", image) # Save frame as JPG file
        return hasFrames
    sec = 0
    frameRate = 0.5 # Change this number to 1 for each 1 second
    
    success = getFrame(sec)
    while success:
        count = count + 1
        sec = sec + frameRate
        sec = round(sec, 2)
        success = getFrame(sec)

这段代码从视频中提取帧并以.jpg格式保存帧

import cv2
import numpy as np
import os

# set video file path of input video with name and extension
vid = cv2.VideoCapture('VideoPath')


if not os.path.exists('images'):
    os.makedirs('images')

#for frame identity
index = 0
while(True):
    # Extract images
    ret, frame = vid.read()
    # end of frames
    if not ret: 
        break
    # Saves images
    name = './images/frame' + str(index) + '.jpg'
    print ('Creating...' + name)
    cv2.imwrite(name, frame)

    # next frame
    index += 1

这个函数以1帧/秒的速度从视频中提取图像，此外，它还识别最后一帧并停止读取:

import cv2
import numpy as np

def extract_image_one_fps(video_source_path):

    vidcap = cv2.VideoCapture(video_source_path)
    count = 0
    success = True
    while success:
      vidcap.set(cv2.CAP_PROP_POS_MSEC,(count*1000))      
      success,image = vidcap.read()

      ## Stop when last frame is identified
      image_last = cv2.imread("frame{}.png".format(count-1))
      if np.array_equal(image,image_last):
          break

      cv2.imwrite("frame%d.png" % count, image)     # save frame as PNG file
      print '{}.sec reading a new frame: {} '.format(count,success)
      count += 1

从这里下载这个视频，这样我们就有了相同的测试视频文件。确保mp4文件与python代码位于同一目录。然后确保从相同的目录运行python解释器。

然后修改代码，抛弃浪费时间的waitKey，也没有窗口，它不能捕捉键盘事件。同时，我们打印success值以确保它成功读取帧。

import cv2
vidcap = cv2.VideoCapture('big_buck_bunny_720p_5mb.mp4')
success,image = vidcap.read()
count = 0
while success:
  cv2.imwrite("frame%d.jpg" % count, image)     # save frame as JPEG file      
  success,image = vidcap.read()
  print('Read a new frame: ', success)
  count += 1

这是怎么回事?

这是对python 3之前答案的一个调整。x来自@ gsurprised，我想把它贴在评论里，但是没有足够的声誉

import sys
import argparse

import cv2
print(cv2.__version__)

def extractImages(pathIn, pathOut):
    vidcap = cv2.VideoCapture(pathIn)
    success,image = vidcap.read()
    count = 0
    success = True
    while success:
      success,image = vidcap.read()
      print ('Read a new frame: ', success)
      cv2.imwrite( pathOut + "\\frame%d.jpg" % count, image)     # save frame as JPEG file
      count += 1

if __name__=="__main__":
    print("aba")
    a = argparse.ArgumentParser()
    a.add_argument("--pathIn", help="path to video")
    a.add_argument("--pathOut", help="path to images")
    args = a.parse_args()
    print(args)
    extractImages(args.pathIn, args.pathOut)

下面的脚本将提取帧每半秒的所有视频在文件夹。(适用于python 3.7)

import cv2
import os
listing = os.listdir(r'D:/Images/AllVideos')
count=1
for vid in listing:
    vid = r"D:/Images/AllVideos/"+vid
    vidcap = cv2.VideoCapture(vid)
    def getFrame(sec):
        vidcap.set(cv2.CAP_PROP_POS_MSEC,sec*1000)
        hasFrames,image = vidcap.read()
        if hasFrames:
            cv2.imwrite("D:/Images/Frames/image"+str(count)+".jpg", image) # Save frame as JPG file
        return hasFrames
    sec = 0
    frameRate = 0.5 # Change this number to 1 for each 1 second
    
    success = getFrame(sec)
    while success:
        count = count + 1
        sec = sec + frameRate
        sec = round(sec, 2)
        success = getFrame(sec)