Transform hog descriptor from Matlab to Java OpenCV

I have some codes which written in Matlab, and I want to convert them into Java OpenCV, to be suitable for Android devices. In Matlab code, I use extractHOGFeatures which is a function in the computer vision toolbox to extract the hog vector.While I use HOGDescriptor class in OpenCV to extract the hog vector. However, the output vector from both is different from each other. I try to understand the problem and what I found are: the block size, the cell size, the block overlap and the number of bins are the same in both vectors that obtained from extractHOGFeatures (Matlab) and HOGDescriptor class(OpenCV). But the size of sliding window in OpenCV is 64*128. While in Matlab I can not determine what is the default size of the sliding window even when I access the documentary of the function. Can anybody help me how I can obtain the same output? I need OpenCV modification, not Matlab since in my project situation I can not change the Matlab code