Methods and apparatus for deriving composite tracks with track grouping

Abstract

The techniques described herein relate to methods, apparatus, and computer readable media configured to derive a composite track. Three-dimensional video data includes a plurality of two-dimensional sub-picture tracks associated with a viewport. A composite track derivation for composing the plurality of two-dimensional sub-picture tracks for the viewport includes data indicative of the plurality of two-dimensional sub-picture tracks belonging to a same group, placement information to compose sample images from the plurality of two-dimensional tracks into a canvas associated with the viewport, and a composition layout operation to adjust the composition if the canvas comprises a composition layout created by two or more of the plurality of two-dimensional sub-picture tracks composed on the canvas. The composite track derivation can be encoded and/or used to decode the three-dimensional video data.