Methods and apparatus for deriving composite tracks

Abstract

The techniques described herein relate to methods, apparatus, and computer readable media configured to process (including encoding and decoding) composition layouts. The video data includes a plurality of encoded two-dimensional sub-picture tracks associated with a viewport and a composition operation to compose the tracks. The composition operation comprises data indicative of a composition to perform on the plurality of two-dimensional sub-picture tracks to compose the 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 plurality of two-dimensional tracks are composed into the canvas according to the composition, comprising determining two or more of the composed two-dimensional sub-picture tracks comprise the composition layout, and adjusting the composition based on the composition layout operation to compensate for the composition layout.