A new bitstream random access scheme using multipicture motion-compensated prediction

Multipicture motion-compensated prediction is exploited to improve compression performance in the up-to-date video coding standards. However, in order to support random access into video bitstream, a restriction on multipicture motion-compensated prediction is introduced: the number of reference pictures has to be limited so that the pictures prior to random access point (RAP) are not allowed to be referenced by those predictive pictures following the RAP. This restriction leads to a decrease of coding efficiency. In this paper, a new kind of picture for reference, the recovery picture, is proposed to compensate the decrease of coding efficiency by taking full use of multipicture motion-compensated prediction. Furthermore, the proposed scheme supports random access without the assistance of the transmitting end. Some factors affecting the proposed schemeiquests performance are discussed. The experimental results show that the proposed random access scheme achieves better compression performance compared with the existing random access scheme.