In this paper, secondary development of Live555 open source projects was achieved, designing and preliminary implementing a real-time streaming media transmission system. WebcamFrame Source and WebcamOndemand MediaSubsession classes are added to LiveMedia Library, realizing the real-time receiving and forwarding H.264 stream; at the same time, video captrue and H.264 coding part are also added, achieving video capture, H.264 coding, and transmission in real time. The proposed design helps solving the problems of time delay and out of sync when transferring multimedia data over a network, which can improve robustness and scalability of the system.