使用 python opencv 播放视频文件

Question

I'm trying to play a video file using python opencv this is my code , but it is not showing the vidfeo file when I run the code

import numpy as np
import cv2

cap = capture =cv2.VideoCapture('C2.mp4')
while(cap.isOpened()):
    ret, frame = cap.read()

    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    cv2.imshow('frame',gray)
    cv2.waitKey(1)

cap.release()
cv2.destroyAllWindows()

I tried the answer in : link but not working again

Answer 1

I think u just have to increase the number inside cv2.waitKey() function to may be 25 or 30. You should get the desired result.

Also, there is no need to write cap = capture = cv2.......

Simply, writing,

cap = cv2.videoCapture('path of the video')

should work as well . Hope it works.

Answer 2

import numpy as np
import cv2

cap = cv2.VideoCapture('C2.mp4')
while(cap.isOpened()):
    ret, frame = cap.read()
    if ret == True:
        gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
        cv2.imshow('frame', gray)
        # & 0xFF is required for a 64-bit system
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break
    else:
        break
cap.release()
cv2.destroyAllWindows()

Answer 3

This code worked for me. It shows both the original and the grayscale video output. Press 'q' to exit. I also didnt see the need for cap = capture... in your code.

import cv2
import numpy as np

cap = cv2.VideoCapture(0)
while True:
ret, frame = cap.read()
    gray = cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)
    cv2.imshow('frame',frame)
    cv2.imshow('grayF',gray)
    if cv2.waitKey(1) & 0xFF == ord('q'):
         break

cap.release()
cv2.destroyAllWindows()

Answer 4

Try using this

cv.CaptureFromFile()

and also check out this link http://opencv-python-tutroals.readthedocs.org/en/latest/py_tutorials/py_gui/py_video_display/py_video_display.html

Answer 5

First of all, there is no need of capture as you are not using capture in your code. The reason why your video file is not showing because you haven't saved it in the same directory, where you have saved the code.

You can either give the path where your file is saved as shown below

cap = cv2.VideoCapture('(path to the video file)/cv2.mp4')

Again you need to change the argument inside waitKey otherwise the program will not close the window that shows the video correctly.

Try out the following, it will definitely work. Put an if statement with waitKey() function and increase the argument which indicates the number of milliseconds it will wait for a key function to 25 or whatever number you may like so that when you press ESC key, the window will be destroyed:

if cv2.waitKey(25) & 0xFF == 27:
  break

Answer 6

The problem in my code was in the part (While). It should be while (True) instead the one in your code

Answer 7

ren opencv_ffmpeg.dll到opencv_ffmpeg2413.dll在你的项目目录中，如果opencv-2.4.13.exe