Intermedia-based video adaptation system: Design and implementation

摘要

Video adaptation is a promising technique to bridge the gap between network status, device capabilities, and user preferences in pervasive media applications. However, conventional adaptation frameworks based on either transcoding or multiple pre-transcoding are not able to accommodate large numbers of users with diversified applications. This paper introduces an intermediate video description called “Intermedia”, which consists of multiple level video signal components, such as texture, motion, and rate control information, as well as some semantic features, such as structural characteristics and Region Of Interest (ROI) information. It is generated off-line and stored in the video server or media gateway. Intermedia is then used to design a novel video adaptation system. The proposed adaptation system quickly and easily generates the required bit stream from Intermedia with very low complexity to fulfill a series of specific adaptation requirements, e.g., bitrate conversion, temporal/spatial resolution reduction, video summarization, ROI browsing, and some multi-level adaptations involving both signal level and semantic level adaptation. The satisfactory performance of such a system demonstrates the effectiveness and efficiency of the proposed video adaptation framework.