Try including the full file path in cv2.VideoCapture and be sure to change the "\" to "/". OpenCV doesn't like the forward slashes for some reason. Example: cv2.VideoCapture('C:/Project/Videos/test.mpg') Also, see my answer here for more clarification on proper codecs to use: (http://answers.opencv.org/question/66545/problems-with-the-video-writer-in-opencv-300/). Hope this helps!