QBR Metadata To Improve Streaming Efficiency and Quality

• Published in: SMPTE 2017 Annual Technical Conference and Exhibition pp. 1 - 9
• Main Authors: Cooper, William, Farrell, Sue, Subramanian, Kumar
• Format: Conference Proceeding
• Language: English
• Published: SMPTE 01.10.2017
• Subjects: ABR; metadata; QBR; streaming
• ISBN: 9781614829591; 1614829594
• DOI: 10.5594/M001784

QBR improves the efficiency of adaptive bitrate video delivery by providing additional metadata describing the visual complexity and encoding quality of each media segment at each data rate. This enables a compatible player to make better adaptation decisions about when to switch between different data rate renditions. In addition to factors such as the state of the local buffer and previous data transfer rates, the heuristics employed can now include information about the relative visual complexity and encoding fidelity of future segments at different data rates. The media player can use this to plan and optimise media requests. Segments with simple scenes that do not benefit from encoding at higher data rates can be replaced with encodings at a lower data rate. - The result is a typical reduction in the volume of data delivered by 30% or more without reducing perceived quality. This efficiency gain can optionally be used to deliver higher data rate segments for more complex scenes, increasing perceived quality where it matters most, while still reducing delivery costs. Effectively, this brings the benefits of variable bitrate encoding to the multi-bitrate schemes that are widely used for adaptive bitrate streaming. - The key to this approach is the provision of information to characterise each video segment at each encoded data rate. This metadata can be produced by video encoders or be extracted from rapid analysis of encoded segments. Formalising the semantics and syntax of this metadata allows interoperability across the ecosystem. - The system is backwards compatible with existing compression schemes, including H.264/AVC and H.265/HEVC, and current HLS, HDS, Smooth Streaming and MPEG-DASH formats. Integrations are already available with popular encoders and players to provide plug-and-play compatibility, enabling service providers and media distributors to benefit from QBR. - This paper presents the benefits of the approach, provides examples of the results that can be achieved, and discusses the opportunities for standardisation of the metadata, while enabling differentiation in implementation for its generation and use.