Synchronized One-to-many Media Streaming employing Server-Client Coordinated Adaptive Playout Control

& h 6 £ x+ þ A F Ò q t] j# Q\ ¦ s 6 xô Ç 1 l xl o) a { 9 @ / p n # Q Û ¼à Ôo b ç Abstract A new inter-client synchronization framework for one-to-many (i.e., multicast) media streaming is proposed employing a server-client coordinated adaptive playout control. The proposed adaptive player controls the playback speed of audio and video by adopting the timescale modification of audio. Based on the overall synchronization status as well as the buffer occupancy level, the playout speed of each client is manipulated within a perceptually tolerable range. Additionally, the server implicitly helps increasing the time available for retransmission while the clients perform an interactive error recovery mechanism with the assistance of playout control. By coordinating the playout speed of each client, the inter-client synchronization with respect to the target presentation time is smoothly achieved. RTCP-compatible signalling between the server and group-clients is performed, where the exchange of controlling message is restricted. The network-simulator based simulations show that the proposed framework can reduce the playout discontinuity without degrading the media quality, and thus mitigate the client heterogeneity. adaptive playout control.