Abstract
In recent years, multimedia improving, bandwidth increasing and the popular for internet have made information receiving much more convenient. The fast growing of digital content technique keeps multimedia service giver provide more internet service, including video on demand, distance learning and movie sharing. User can take advantage of different multimedia access device (e.g. computer, 3G mobile, PDA, etc. ) to conveniently retrieve real-time data or pre-stored information by media streaming technique. In the digital archives, videos are the most amounts of data. In order to reduce the storage needs of video data, the videos have usually been compressed by the MPEG-x/H.26x codec or the proprietary codec (for example, Microsoft WMV-9 or RealNetwork). When we want to watch video, we need corresponding decoder/encoder to carry out decoding/encoding ; For video format transformation, we use transcoder to increase transform efficiency and to save time. With the development of video compression technology, high efficiency video coding would be used to compress video data. Therefore, the digital archives would contain various videos compressed by various video coding techniques. With the use of new video format, the programmer must to build corresponding codec timely. It is diseconomy for instant requirement and manpower. On the other hand, analogue operation functional unit usually owns similar algorithm for video codec. Compare late coding format to the old one, and we know most of the operation function are reused. If we can standardize these functional units, new coding tool will be assembled easily. In this research, we adopt the Reconfigurable Video Coding (RVC) technique by which a decoder can be built dynamically and flexibly, to develop the universal video transcoder. We will analyze the various functional units of the MPEG-2/4 video coding standards, and then implement the functional units. Based on the function units repository, we will construct the universal video transcoder in order to achieve the reconfigurable transcoder architecture. We would implement the optimized rate control algorithm for the RVC transcoding platform. Our research also discussed how to transcode the video bistream to the least bit rate in constant quality. The constant-quality variable bit rate algorithm is useful in data saving application.