FFFEEE: Finally, I've got the letter with confirmation that NetVision DVR doesn't support Motion Jpeg. It means I have to find another solution. Btw, thanks for supporting.
It's a pitty.
But I have to say that, Motion JPEG stream has a very very big data size, this would be a big problem with network communication. So I think there is few boards based on Motion JPEG stream, our DVR Server software is designed to work with boards, so we don't support Motion JPEG stream.