After I connected to the IP channel, there is no video output in the one*window or the multiple*window mode. But I can see there is bit stream.

There are following possibilities:

Check the main stream/sub stream type of the camera is H.264 or not.
Check the device supports camera main stream/sub stream resolution or not (such as 1080P, 720P, 960H, D1, HD1 and etc.).
Check the camera setup. Please make sure It supports the products of other manufacturers.