DCT-based video frame-skipping transcoder

2002-2003 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Low-complexity and high-quality frame-skipping transcoder for continuous presence multipoint video conferencing

2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Fast compressed domain watermarking of MPEG multiplexed streams

In this paper, a new technique for watermarking of MPEG compressed video streams is proposed. The watermarking scheme operates directly in the domain of MPEG multiplexed streams. Perceptual models are used during the embedding process in order to preserve the quality of the video. The watermark is embedded in the compressed domain and is detected without the use of the original video sequence. Experimental evaluation demonstrates that the proposed scheme is able to withstand a variety of attacks. The resulting watermarking system is very fast and reliable, and is suitable for copyright protection and real-time content authentication applications

Low-complexity and high quality frame-skipping transcoder

2000-2001 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

New architecture for dynamic frame-skipping transcoder

2002-2003 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Dynamic region of interest transcoding for multipoint video conferencing

This paper presents a region of interest transcoding scheme for multipoint video conferencing to enhance the visual quality. In a multipoint videoconference, usually there are only one or two active conferees at one time which are the regions of interest to the other conferees involved. We propose a Dynamic Sub-Window Skipping (DSWS) scheme to firstly identify the active participants from the multiple incoming encoded video streams by calculating the motion activity of each sub-window, and secondly reduce the frame-rates of the motion inactive participants by skipping these less-important subwindows. The bits saved by the skipping operation are reallocated to the active sub-windows to enhance the regions of interest. We also propose a low-complexity scheme to compose and trace the unavailable motion vectors with a good accuracy in the dropped inactive sub-windows after performing the DSWS. Simulation results show that the proposed methods not only significantly improve the visual quality on the active subwindows without introducing serious visual quality degradation in the inactive ones, but also reduce the computational complexity and avoid whole-frame skipping. Moreover, the proposed algorithm is fully compatible with the H.263 video coding standard. 1

Dynamic frame skipping for high-performance transcoding

2001-2002 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

On the architecture of H.264 to H.264 homogeneous transcoding platform

2007-2008 > Academic research: refereed > Invited conference paperVersion of RecordPublishe