%0 Journal Article
%T Real-Time Adaptive Content-Based Synchronization of Multimedia Streams
%A Imad H. Elhajj
%A Nadine Bou Dargham
%A Ning Xi
%A Yunyi Jia
%J Advances in Multimedia
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/914062
%X Traditional synchronization schemes of multimedia applications are based on temporal relationships between inter- and intrastreams. These schemes do not provide good synchronization in the presence of random delay. As a solution, this paper proposes an adaptive content-based synchronization scheme that synchronizes multimedia streams by accounting for content in addition to time. This approach to synchronization is based on the fact that having two streams sampled close in time does not always imply that these streams are close in content. The proposed scheme primary contribution is the synchronization of audio and video streams based on content. The secondary contribution is adapting the frame rate based on content decisions. Testing adaptive content-based and adaptive time-based synchronization algorithms remotely between the American University of Beirut and Michigan State University showed that the proposed method outperforms the traditional synchronization method. Objective and subjective assessment of the received video and audio quality demonstrated that the content-based scheme provides better synchronization and overall quality of multimedia streams. Although demonstrated using a video conference application, the method can be applied to any multimedia streams including nontraditional ones referred to as supermedia like control signals, haptic, and other sensory measurements. In addition, the method can be applied to synchronize more than two streams simultaneously. 1. Introduction Three types of applications are recognized over the Internet: asynchronous, synchronous, and interactive synchronous. Asynchronous applications do not involve simultaneous transfer of media streams, like file transfer and web browsing. Such applications do not require strict timing from the network. In synchronous applications, such as video clip viewing, multiple media streams (audio and video) are to be transferred simultaneously. In this type of applications, synchronous display of media streams is required. However, since no interactivity is involved, these applications do not enforce strict delay requirements on the network. In this case, applications can buffer data before starting to render audio and video to mask the network delays. As for the interactive synchronous applications, they include real-time applications with an interactive nature such as video conferencing and networked gaming. They also include nontraditional applications using ˇ°supermediaˇ± such as remote surgery and teleoperation [1, 2]. Due to their interactive nature these applications can
%U http://www.hindawi.com/journals/am/2011/914062/