Utilities for capture in OpenCV

capture_util.py

import cv2
import cv2.cv as cv
"""
Got the idea from http://newpathprep.wordpress.com/2012/08/13/opencv-forward-and-rewind-avi/
He has done it in C++.
"""
def start(capture, n):
    cv.SetCaptureProperty(capture, cv.CV_CAP_PROP_POS_FRAMES, n-1)

def rewind(capture):
    cv.SetCaptureProperty(capture, cv.CV_CAP_PROP_POS_FRAMES, 0)

def getFrame(capture, frame):
    number_frame = int(cv.GetCaptureProperty(capture, cv.CV_CAP_PROP_POS_FRAMES))
    cv.SetCaptureProperty(capture, cv.CV_CAP_PROP_POS_FRAMES, frame-1)
    img = cv.QueryFrame(capture)
    cv.SetCaptureProperty(capture, cv.CV_CAP_PROP_POS_FRAMES, number_frame)
    return img

def skipFrames(capture, n):
    number_frame = int(cv.GetCaptureProperty(capture, cv.CV_CAP_PROP_POS_FRAMES))
    cv.SetCaptureProperty(capture, cv.CV_CAP_PROP_POS_FRAMES, number_frame + n - 1)