OpenCV Video Tutorial bug (Bug #4091)

Added by Dan Goodrick about 10 years ago. Updated about 10 years ago.

Status:Cancelled Start date:2014-12-29
Priority:Normal Due date:
Assignee:- % Done:

90%
Category:documentation
Target version:3.0
Affected version:branch 'master' (3.0-dev) Operating System:Windows
Difficulty:Easy HW Platform:x64
Pull request:

Description

http://docs.opencv.org/trunk/doc/py_tutorials/py_gui/py_video_display/py_video_display.html#display-video

Saving a Video section

import numpy as np
import cv2
cap = cv2.VideoCapture(0)
  1. Define the codec and create VideoWriter object
    fourcc = cv2.VideoWriter_fourcc(*'XVID')

This line fails: cv2.VideoWriter_fourcc(*'XVID')

Workaround is to replace the entire line with:
fourcc = cv2.cv.CV_FOURCC(*'XVID')

History

#1
Updated by Ariel Machado about 10 years ago

I checked the referred code using OpenCV 3.0.0-beta with Python 2.7.8 |Anaconda 2.1.0 (64-bit)| and is working correctly in my box (Win7 64-bit):

import numpy as np
import cv2

print "OpenCV version ", cv2.__version__

cap = cv2.VideoCapture(0)

# Define the codec and create VideoWriter object
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi',fourcc, 20.0, (640,480))

while(cap.isOpened()):
    ret, frame = cap.read()
    if ret==True:
        frame = cv2.flip(frame,0)

        # write the flipped frame
        out.write(frame)

        cv2.imshow('frame',frame)
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break
    else:
        break

# Release everything if job is finished
cap.release()
out.release()
cv2.destroyAllWindows()

According the documentation the example is OK and this static method constructs the fourcc code of the codec to be used in the constructor:
http://docs.opencv.org/3.0-beta/modules/videoio/doc/reading_and_writing_video.html?highlight=videowriter_fourcc#cv2.VideoWriter_fourcc

What you mean by "This line fails"?
Take a look to this documentation about how to report a bug:
http://code.opencv.org/projects/OpenCV/wiki/WikiStart#Reporting-bugs

Ariel.

  • % Done changed from 0 to 90
  • Status changed from New to Incomplete

#2
Updated by Steven Puttemans about 10 years ago

Checked and works like a charm here. Can you please get latest 3.0 branch and be sure your system is correctly configured?
Reopen if needed. Cleaning up documentation section for now.

  • Status changed from Incomplete to Cancelled

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