public void setSize(int width, int height) {
		mHeight = height;
		mWidth = width;
		mSliceHeight = height;
		mStride = width;
		mSize = mWidth*mHeight;
	}
Converts from NV21 to YUV420 semi planar or planar.
src/net/majorkernelpanic/streaming/hw/NV21Convertor.java