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Abstract-The performance evaluation of video transport mechanisms becomes increasingly important as encoded video accounts for growing portions of the network traffic. Compared to the widely studied MPEG-4 encoded video, the recently adopted H.264 video coding standards include novel mechanisms, such as hierarchical B frame prediction structures and highly efficient quality scalable coding, that have important implications for network transport. This tutorial introduces a trace-based evaluation methodology for the network transport of H.264 encoded video. We first give an overview of H.264 video coding, and then present the trace structures for capturing the characteristics of H.264 encoded video. We give an overview of the typical video traffic and quality characteristics of H.264 encoded video. Finally, we explain how to account for the H.264 specific coding mechanisms, such as hierarchical B frames, in networking studies.

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Abstract-The network transport of 3D video, which contains two views of a video scene, poses significant challenges due to the increased video data compared to conventional single-view video. Addressing these challenges requires a thorough understanding of the traffic and multiplexing characteristics of the different representation formats of 3D video. We examine the average bitrate-distortion (RD) and bitrate variability-distortion (VD) characteristics of three main representation formats. Specifically, we compare multiview video (MV) representation and encoding, frame sequential (FS) representation, and side-by-side (SBS) representation, whereby conventional single-view encoding is employed for the FS and SBS representations. Our results for long 3D videos in full HD format indicate that the MV representation and encoding achieves the highest RD efficiency, while exhibiting the highest bitrate variabilities. We examine the impact of these bitrate variabilities on network transport through extensive statistical multiplexing simulations. We find that when multiplexing a small number of streams, the MV and FS representations require the same bandwidth. However, when multiplexing a large number of streams or smoothing traffic, the MV representation and encoding reduces the bandwidth requirement relative to the FS representation.

Abstract-Encoded video is expected to contribute a significant portion of the load on future communication systems and networks, which often employ statistical multiplexing. In such systems, the number of video streams that can be supported depends both on the mean bit rate as well as bit rate variability of the video streams. At the same time, the utility (revenue) earned from video streaming depends both on the number of supported video streams as well as their quality level. In this paper we examine the interplay between video quality, traffic variability, and utility for open-loop encoded video. We introduce the rate variability-distortion (VD) curve which relates the bit rate variability to the quality level of an encoded video. We find that the VD curve generally exhibits a characteristic "hump" behavior of first increasing, peaking, and subsequently decreasing variability for increasing quality. We examine the impact of video content characteristics, encoding parameters, and traffic smoothing on the VD behavior. We describe a methodology for assessing (i) the set of the video streams that can be supported with a statistical quality of service requirement, and (ii) the utility earned from video streaming over a link. This methodology is based on the rate-distortion and rate variability-distortion characteristics of the videos. We find that the statistical multiplexing gain and the utility as a function of the video quality level typically exhibit a "hump" similar to the VD curve.Index Terms-Network utility, statistical multiplexing, variable bit rate video, video content, video quality, video streaming, video traffic.