Design And Realization Of Wireless Audio And Video Transmission System Based On RTP

Wireless Audio and Video Transmission System Based on RTP is designed for Synthetic Aperture Radar Landmine Detection and applies to the communication of the front landmine detection device and the back podium. Via this system, we can send the image of the detection region to the back podium, and realize voice communication. The system provides video support and decision-making for detecting suspicious landmines exactly.There exists two challenging problems in wireless audio and video delivery. One is high efficient compression of source for fully utilization of channel band width, the other is providing control of quality of service. Besides, the system needs voice communication for many persons at the same time, so we need to realize voice mixture function. In addition, Voice jitter and delay have great influence on the quality of network talking, we should eliminate this influence. Considering these factors, when developing this system, we should pay great attention to the requirements as follows: Quality of Service, Real-time Ability, and Channel Band Width.The actuality of audio/video transmission technology is introduced firstly, and then analyzes three familiar algorithms about video compression, including H.263, MPEG-4, and H.264. Audio/video transmission asks for high real-time performance. TCP doesn't meet this requirement for its error detection and retransmission mechanism. If we singly adopt UDP, transmission quality will be very poor, because UDP doesn't provide any quality of service. Combining RTP/RTCP and UDP together will meet real-time requirements and provide quality of service at the same time.The design and realization of wireless audio and video transmission subsystem is introduced, which contains two parts: wireless audio transmission based on directplay voice and wireless video transmission based on directshow. The time stamp of the RTP and the jitter buffer are used to restrain the voice jitter and delay, the RTP/RTCP is used to transport MPEG-4 bitstreams. Applications show that this system implemented by the scheme not only present satisfactory reconstructed audio and video but also have good stability and utilizes the network resources.