Mesh node coding to enable object based functionalities within a motion compensated transform video coder

摘要

A method and apparatus for coding video data permits coding of video information with optional, enhanced functionalities. Video data is coded as base layer data and enhancement layer data. The base layer data includes convention motion compensated transform encoded texture and motion vector data. Optional enhancement layer data contains mesh node vector data. Mesh node vector data of the enhancement layer may be predicted based on motion vectors of the base layer. Thus, simple decoders may decode the base layer data and obtain a basic representation of the coded video data. However, more powerful decoders may decode both the base layer and enhanced layer to obtain decoded video permitting functionalities. An embodiment of the present invention provides a back channel that permits a decoder to affect how mesh node coding is performed in the encoder. The decoder may command the encoder to reduce or eliminate encoding of mesh node motion vectors. The back channel finds application in single layer systems and two layer systems.