Advances in channel-adaptive video streaming

Despite the well-known challenges of variations in throughput, delay, and packet loss over the Internet, video streaming has experienced phenomenal growth, owing to the extensive research in video coding and transmission. In this paper, we review several recent advances for channel-adaptive video streaming that, we believe, will benefit the design of video streaming systems in the future. Employed in different components of the system, these techniques have the common objective of providing efficient, robust, scalable, and low-latency streaming video. Firstly, by allowing the client to control the rate at which it consumes data, adaptive media playout can be used to reduce receiver buffering and therefore average latency, and provide limited rate scalability. Secondly, rate-distortion optimized packet scheduling, a transport technique, provides a flexible framework to determine the best packet to send, given the channel behaviors, the packets' deadlines, their transmission histories, the distortion reduction associated with sending each packet, and the interpacket dependencies. Thirdly, at the source encoder, channel-adaptive packet-dependency control can greatly improve the error resilience of streaming video and reduce latency. Finally, we address the specific additional challenges for wireless video streaming. We consider three architectures for wireless video and discuss the utility of the reviewed techniques for each architecture. Copyright (C) 2002 John Wiley Sons, Ltd.