MPEG DASH SRD: spatial relationship description

This paper presents the Spatial Representation Description (SRD) feature of the second amendment of MPEG DASH standard part 1, 23009-1:2014 [1]. SRD is an approach for streaming only spatial sub-parts of a video to display devices, in combination with the form of adaptive multi-rate streaming that is intrinsically supported by MPEG DASH. The SRD feature extends the Media Presentation Description (MPD) of MPEG DASH by describing spatial relationships between associated pieces of video content. This enables the DASH client to select and retrieve only those video streams at those resolutions that are relevant to the user experience. The paper describes the design principles behind SRD, the different possibilities it enables and examples of how SRD was used in different experiments on interactive streaming of ultra-high resolution video.