Multiple description video coding through adaptive segmentation

摘要

Multiple description video coding is one method that can be used to reduce detrimental effects caused by transmission over lossy packet networks. In a multiple description system, a video sequence is segmented into two or more complimentary streams in such a way that each stream is independently decodable. When combined, the streams provide the highest level of quality, yet if one of the streams is lost or delivered late the video can be played out with only a slight reduction in overall quality. Each approach to multiple description coding consists of a tradeoff between compression efficiency and robustness. How efficiently each method achieves this tradeoff depends on the level of quality and robustness desired and on the characteristics of the video itself. Previous approaches to multiple description coding have made the assumption that a single segmentation method would be used for an entire sequence. Yet, the optimal method of segmentation can vary depending on the goals of the system, it can change over time, and it can vary within a frame. This work introduces a unique approach to multiple description coding through the use of adaptive segmentation. By selecting from a set of segmentation methods, the system adapts to the local characteristics of the video and maximizes tradeoff efficiency. We present an overview of this system and analyze its performance on real video sequences.