The effects of priority levels and buffering on the statistical multiplexing of single-layer H.264/AVC and SVC encoded video streams

H.264/Advanced Video Coding (AVC) employs classical bi-directional encoded (B) frames that depend only on intra-coded (I) and predictive encoded (P) frames. In contrast, H.264 Scalable Video Coding (SVC) employs hierarchical B frames that depend on other B frames. A fundamental question is how many priority levels single-layer H.264 video encodings require when the encoded frames are statistically multiplexed in transport networks. We conduct extensive simulation experiments with a modular statistical multiplexing structure to uncover the impact of priority levels for a wide range of multiplexing policies. For the bufferless statistical multiplexing of both H.264/AVC and SVC we find that prioritizing the frames according to the number of dependent frames can increase the number of supported streams up to approximately 8%. In contrast, for buffered statistical multiplexing with a relatively small buffer size, frame prioritization does generally not increase the number of supported streams.