Videocapture start latency for a rtsp-stream

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Hi, i want to ask if it exists a faster start approach to obtain a rtsp-stream than with a videocapture object and its member function open. Based on the fact that i need to switch between two cameras and can only attach the two cameras to the same address, the open-function of a videocapture object is very time-consuming task. I need to wait at least 30 seconds before the starting of the stream at the moment.Any suggestion to be faster with opencv or with another 3rd party library would be highly welcomed. I use c++ and opencv 3.0.0 at the moment. regards Phillip