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— Digital video coding standards such as H.263 and MPEG are becoming more and more important for multimedia applications. Due to the huge amount of computations required, there are significant efforts to speed up the processing of video encoders. Previously, the efforts were mainly focused on the fast motion-estimation algorithm. However, as the(More)
— In transcoding, simply reusing the motion vectors extracted from an incoming video bit stream may not result in the best quality. In this paper, we show that the incoming motion vectors become nonoptimal due to the reconstruction errors. To achieve the best video quality possible, a new motion estimation should be performed in the transcoder. We propose a(More)
We propose that the information access behavior of a group of people can be modeled as an information flow issue, in which people intentionally or unintentionally influence and inspire each other, thus creating an interest in retrieving or getting a specific kind of information or product. Information flow models how information is propagated in a social(More)
In this paper, we propose a new way to automatically model and predict human behavior of receiving and disseminating information by analyzing the contact and content of personal communications. A personal profile, called CommunityNet, is established for each individual based on a novel algorithm incorporating contact, content, and time information(More)
In H.264/MPEG-4 AVC, MacroBlock (MB) mode decision and motion estimation (ME) is one of the most computationally expensive processes. This paper proposes a fast intermode decision and ME algorithm. Experimental results show that the proposed algorithm could achieve similar Rate-Distortion (R-D) performance with about 50% computation saving, compared to the(More)
We investigate the scenario of using the Automatic Repeat reQuest (ARQ) retransmission scheme for two-way video communications over wireless Rayleigh fading channels. Video quality is the major concern of these applications. We show that during the retransmissions of error packets, due to the reduced channel throughput, the video encoder buffer may fill-up(More)
Invited Paper Video transcoding, due to its high practical values for a wide range of networked video applications, has become an active research topic. In this paper, we outline the technical issues and research results related to video transcoding. We also discuss techniques for reducing the complexity, and techniques for improving the video quality, by(More)