This adds support for a general framework for sample “variants” in the ISOBMFF. This would be used by a forensic “watermarking” system to modify the base sample, but is independent of the “watermarking” algorithm. Variants are sample data that may be used by a decoder and DRM system to ultimately output video or audio that is marked in a way that can be unique to individual decoders or decoder product models. The application of the variants during the decode process is under control of the DRM system (and ultimately the content provider).
