检测视频中的媒体分辨率变化

Question

I tried to search in SO but could not find.I want to iterate video file frame by frame and want to detect if there is any point when resolution of two consecutive frame changes. The desired functionality in pseudocode:

resolution1 = videoFile[0]->resolution
resolution2 = 0;
for frame in videoFile[1:]:
    resolution2 = frame->resolution
    if (resolution1 != resolution2):
        print 'Changes occured'
    else:
        resolution1 = resolution2

Please give me the name of a library to implement them, I have tried and read documentation of OpenCV and PiCamera. Thanks in advance

Answer 1

You should use OpenCV to iterate through each frame. This should print "Changes occured" whenever the video changes resolution:

import cv2

capture1 = cv2.VideoCapture('videoname') #Open the video

ret, frame = capture1.read() #Read the first frame

resolution1 = frame.shape #Get resolution

while capture1.isOpened():
    ret, frame = capture1.read() #Read the next frame
    if ret == False or frame == None:
        break #Quit if video ends

    resolution2 = frame.shape #Get the new resolution

    if resolution1 != resolution2:
        print 'Changes occured'
        #Change resolution1 to resolution2 so that the new resolutions are
        #compared with resolution2, not resolution1.
        resolution1 = resolution2