Error Resilient Video Coding Using B Pictures in H.264
Since the quality of compressed video is vulnerable to errors, video transmission over unreliable Internet is very challenging today. Multi-hypothesis motion-compensated prediction (MHMCP) has been shown to have error resilience capability for video transmission, where each macroblock is predicted by a linear combination of multiple signals (hypotheses). B picture prediction is a special case of MHMCP. In H.264/AVC, the prediction of B pictures is generalized such that both of the two predictions can be selected from the past pictures or from the subsequent pictures. The multiple reference picture framework in H.264/AVC also allows previously decoded B pictures to be used as references for B picture coding. In this paper, we will discuss the error resilience characteristics of the generalized B pictures in H.264/AVC. Three prediction patterns of B pictures are analyzed in terms of their error-suppressing abilities. Both theoretical models (picture level error propagation) and simulation results are given for the comparison.