Error Resilient Video Coding Using Flexible Reference Frames

摘要

Conventional video coding techniques make use of the most recently decoded reference frame(s) for motion-compensated inter prediction. However, it has been shown that to allow using reference frames in a flexible way such that not only the latest reference frames are used is beneficial. A typical use of flexible reference frame is feedback based reference picture selection, wherein error-free reference frames available in both the encoder and decoder sides are selected and used for inter prediction reference. This paper first overviews support of reference picture selection in different video coding standards, and then presents three specific feedback based reference picture selection methods using flexible reference frames. In addition, a novel simple reference frame management method that enables using of flexible reference frame is proposed. The reference frame management method enables much simpler video codec implementations compared to the complex reference frame management methods in H.263 Annex U and H.264/AVC. The proposed coding methods and some conventional methods are compared with each other. Simulation results show significantly improved error resiliency performance of the proposed reference picture selection methods compared to conventional methods. The effect on the performance imposed by feedback delay variation is also shown. Thanks to the merits, support of flexible reference frame and the reference frame management has been adopted to the AVS-M video coding standard.