Python使用OpenCV反向播放视频（）

OpenCV的(开源计算机视觉)是一种计算机视觉库, 其中包含用于对图像或视频执行操作的各种功能。

OpenCV's application areas include :1) Facial recognition system 2) motion tracking 3) Artificial neural network 4) Deep neural network 5) video streamingetc.

在Python中, 可以使用一个名为CV2。 Python不随cv2一起提供, 因此用户需要单独安装它。

对于Windows：pip install opencv-python
对于Linux：sudo apt-get install python-opencv

OpenCv库可用于对视频执行多项操作。让我们尝试使用CV2。将视频作为输入, 然后通过将视频逐帧拆分为反向并将其存储在列表中, 以反向模式播放。获取帧列表后, 我们对帧进行迭代。要以反向模式播放视频, 我们只需要在帧列表中迭代反向即可。使用列表的反转方法可以反转列表中帧的顺序。
下面是实现：

# Python program to play a video # in reverse mode using opencv # import cv2 library import cv2# videoCapture method of cv2 return video object# Pass absolute address of video file cap = cv2.VideoCapture( "video_file_location" )# read method of video object will return # a tuple with 1st element denotes whether # the frame was read successfully or not, # 2nd element is the actual frame.# Grab the current frame. check , vid = cap.read()# counter variable for # counting frames counter = 0# Initialize the value # of check variable check = Trueframe_list = []# If reached the end of the video # then we got False value of check.# keep looping untill we # got False value of check. while (check = = True ):# imwrite method of cv2 saves the # image to the specified format. cv2.imwrite( "frame%d.jpg" % counter , vid) check , vid = cap.read()# Add each frame in the list by # using append method of the List frame_list.append(vid)# increment the counter by 1 counter + = 1# last value in the frame_list is None # because when video reaches to the end # then false value store in check variable # and None value is store in vide variable.# removing the last value from the # frame_list by using pop method of List frame_list.pop()# looping in the List of frames. for frame in frame_list:# show the frame. cv2.imshow( "Frame" , frame)# waitkey method to stoping the frame # for some time. q key is presses, # stop the loop if cv2.waitKey( 25 ) and 0xFF = = ord ( "q" ): break# release method of video # object clean the input video cap.release()# close any open windows cv2.destroyAllWindows()# reverse the order of the element # present in the list by using # reverse method of the List. frame_list.reverse()for frame in frame_list: cv2.imshow( "Frame" , frame) if cv2.waitKey( 25 ) and 0xFF = = ord ( "q" ): breakcap.release() cv2.destroyAllWindows()

输出：