Although random access operations are desirable for on-demand video streaming in peer-to-peer systems, they are difficult to efficiently achieve due to the asynchronous interactive behaviors of users and the dynamic nature of peers. In this paper, we propose a network coding equivalent content distribution (NCECD) scheme to efficiently handle interactive video-on-demand (VoD) operations in peer-to-peer systems.
In NCECD, videos are divided into segments that are then further divided into blocks. These blocks are encoded into independent blocks that are distributed to different peers for local storage. With NCECD, a new client only needs to connect to a sufficient number of parent peers to be able to view the whole video and rarely needs to find new parents when performing random access operations. In most existing methods, a new client must search for parent peers containing specific segments; however, NCECD uses the properties of network coding to cache equivalent content in peers, so that one can pick any parent without additional searches.
Experimental results show that the proposed scheme achieves low startup and jump searching delays and requires fewer server resources. In addition, we present the analysis of system parameters to achieve reasonable block loss rates for the proposed scheme.
An important challenge in a P2P collaborative video-on-demand (VoD) streaming system is to develop an effective content distribution scheme that can support a dynamic network among peers, where autonomic peers can join or leave the system at any time and any place in the network. The situation is further complicated by the need to support random access, such as the trick plays of pause/resume, jump, and fast forward (FF), and rewind. Such trick plays may occur frequently.
Most existing approaches require at least O (log (N)) time to locate the requested segment, where N is the number of segments of the requested video. The scheme we propose in this study can offer a more efficient approach (and one that supports trick plays) to the P2P-based interactive VoD systems.
The proposed scheme avoids these problems by adopting the additional static local storage instead of sliding window playback buffering, to efficiently support users’ interactive operations and decrease complexity.
The advantage of using additional storage is that any user interactivity on the part of the peer does not affect its children from continuing to receive its stored media data. Moreover, observations from a large number of user requesting logs indicate that random seeking is frequently performed by most users.
This is reasonable, as users usually jump directly to the scene of interest and skip boring segments. Therefore, it would be favorable if the system could guarantee peers the ability to jump to any play point in the requested video without searching for new parent peers that possess specific segments.