Adaptive Media Playout

This chapter discusses adaptive media playout (AMP) as a method of reducing the user-perceived latencies that are inherent in systems that send packetized media over best-effort packet networks. These systems strive to allow the immediate display of media data as it is delivered from a remote sender. In practice, however, the systems must buffer an amount of media at the client to prevent packet losses and delays from constantly interrupting the playout of the stream. As more data is buffered, the likelihood of a playout interruption decreases, but the delays that buffering introduces increase. AMP is discussed in the chapter using two popular applications-Internet telephony and video streaming. Internet telephony or voice-over Internet Protocol (VoIP) is used as a representative for bidirectional conversational applications with strict end-to-end delay requirements. Video streaming is selected as an application with comparatively relaxed end-to-end delay requirements. This chapter discusses the receiver buffer in combination with fixed playout as the traditional means of adapting the application to varying transmission characteristics.