| 摘要 |
A system and a method for coding and decoding video data are disclosed. In a system and method of video data compression a video frame (32) is divided into a sequence of image blocks (38), wherein one of several possible block-coding modes is an implicit global motion compensation (IGMC) mode, which is used to copy pixels from a previous frame (32) displaced by a predicted motion vector. In another embodiment of the invention, a system and method of a video data compression, a video frame (32) is segmented into a sequence of slices (36), wherein each slice (36) includes a number of macroblocks (38). Respective slices (36) are encoded and a signal is included in the header (44) of an encoded slice (40) to indicate whether the slice (40) is GMC enabled, that is, whether global motion compensation is to be used in reconstructing the encoded slice. If so, GMC information, such as information representing a set of motion vectors (42a-42d), is included with the slice. In a useful embodiment each slice (36) of a frame (32) contains the same GMC information, to enhance resiliency against errors. In another embodiment different slices (36) of a frame (32) contain different GMC information. In either embodiment, motion vectors (42a-42d) for each image of a particular encoded slice (40) can be reconstructed using GMC information contained only in the particular encoded slice. |
