A point cloud coding structure defines a 'key' point cloud frame, where all references used for predicting point cloud image blocks are limited to the current point cloud frame. A point cloud image block buffer is described, where the list of reference image blocks and their respective bounding boxes from a point cloud frame are stored to be used for prediction of image blocks in another frame. The list of reference image blocks may contain image blocks from the past and image blocks from the future, in case the coding order of point cloud frames is allowed to be different from the presentation order, and bi-directional prediction is used. A similar reference buffer list concept is able to be applied to the layers of the point cloud. A signaling method that correlates the blocks of V-PCC by signaling within the payload the reference to the ID of the block containing the higher-level information is also described.
Point cloud coding structure