Using MPEG DASH SRD for zoomable and navigable video

This paper presents a video streaming client implementation that makes use of the Spatial Relationship Description (SRD) feature of the MPEG-DASH standard, to provide a zoomable and navigable video to an end user. SRD allows a video streaming client to request spatial subparts of a particular video stream, which might be available in multiple resolutions. The paper outlines the design choices enabling the player to render DASH content supporting the SRD feature, such as (i) identifying the total amount of resolution layers and selecting the most appropriate one for the user's current selection (pan or zoom), and (ii) enabling a seamless switch between spatial subparts. Doing so, we provide practical implementation guidelines for applications and services that may want to use the SRD feature of MPEG DASH to provide zoomable and navigable video to end users. The video streaming client is implemented in JavaScript and extends dash.js, an MPEG DASH reference client implementation.