Method and an apparatus for processing a video signal with blocks in direct or skip mode
A method of processing a video signal is disclosed. The present invention includes obtaining a current macroblock type, obtaining skip or direct mode indication information on a partition of the current macroblock according to the current macroblock type, deriving a motion vector of the partition according to the skip or direct mode indication information, and predicting a pixel value of the partition using the motion vector. Accordingly, the present invention obtains a pixel value of a reference block close to an original video using a motion vector, thereby enhancing a reconstruction ratio of the macroblock. As a macroblock uses skip or direct prediction indication information, it is unnecessary to separately code skip mode indication information and direct mode indication information on the macroblock, whereby an information size to be coded can be reduced.
1. A method decoding video data in a coded video data bitstream with a decoding apparatus, the method comprising:
obtaining, with the decoding apparatus, skip mode indication information, the skip mode indication information specifying whether a current block is coded in a skip mode;
deriving, with the decoding apparatus, a motion vector predictor of the current block when the skip mode indication information specifies that the current block is not coded in the skip mode; and
predicting, with the decoding apparatus, a pixel value of the current block based on the motion vector predictor of the current block,
wherein deriving the motion vector predictor of the current block includes:
constructing, with the decoding apparatus, a motion vector predictor list of the current block, the motion vector predictor list including at least two motion vector candidates, list index information being assigned to each of the motion vector candidates included in the motion vector predictor list, the list index information specifying each motion vector candidate, the motion vector candidates including motion vectors of neighboring blocks adjacent to the current block,
obtaining, with the decoding apparatus, motion vector index information of the current block from block-level data in the coded video data bitstream, the motion vector index information specifying a motion vector candidate used for the current block, and
extracting, with the decoding apparatus, from the motion vector predictor list, the motion vector candidate having the list index information corresponding to the obtained motion vector index information, the extracted motion vector candidate being used as the motion vector predictor of the current block.
2. The method of claim 1 , wherein the neighboring blocks include blocks located at a left side and an upper side of the current block.
3. The method of claim 2 , further comprising:
obtaining, with the decoding apparatus, prediction mode information of the current block, the prediction mode information specifying a prediction mode of the current block,
wherein the prediction mode information of the current block is obtained when the skip mode indication information specifies that the current block is not coded in the skip mode.
4. The method of claim 3 , wherein:
the prediction mode includes intra prediction mode and inter prediction mode, and
the motion vector predictor of the current block is derived when the prediction mode information specifies the prediction mode of the current block is the inter prediction mode.
5. The method of claim 1 , further comprising:
obtaining, with the decoding apparatus, a motion vector difference of the current block;
deriving, with the decoding apparatus, a motion vector of the current block by using the motion vector difference of the current block and the motion vector predictor of the current block,
wherein the pixel value of the current block is predicted by motion compensation using the motion vector of the current block.
6. The method of claim 5 , wherein the motion vector difference of the current block is a difference vector between the motion vector of the current block and the motion vector predictor of the current block.
7. A decoder for decoding video data in a coded video data bitstream, the decoder comprising:
one or more processors; and
one or more storage devices storing instructions that are operable, when executed by the one or more processors, to cause the one or more processors to perform operations comprising:
obtaining skip mode indication information, the skip mode indication information specifying whether a current block is coded in a skip mode;
deriving a motion vector predictor of the current block when the skip mode indication information specifies that the current block is not coded in the skip mode; and
predicting a pixel value of the current block based on the motion vector predictor of the current block,
wherein deriving the motion vector predictor of the current block includes:
constructing a motion vector predictor list of the current block, the motion vector predictor list including at least two motion vector candidates, list index information being assigned to each of the motion vector candidates included in the motion vector predictor list, the list index information specifying each motion vector candidate, the motion vector candidates including motion vectors of neighboring blocks adjacent to the current block,
obtaining, with the decoding apparatus, motion vector index information of the current block from block-level data in the coded video data bitstream, the motion vector index information specifying a motion vector candidate used for the current block, and
extracting, with the decoding apparatus, from the motion vector predictor list, the motion vector candidate having the list index information corresponding to the obtained motion vector index information, the extracted motion vector candidate being used as the motion vector predictor of the current block.
8. The decoder of claim 7 , wherein the neighboring blocks include blocks located at a left side and an upper side of the current block.
9. The decoder of claim 8 , wherein the one or more storage devices store instructions that are operable, when executed by the one or more processors, to cause the one or more processors to perform operations comprising:
obtaining prediction mode information of the current block, the prediction mode information specifying a prediction mode of the current block,
wherein the prediction mode information of the current block is obtained when the skip mode indication information specifies that the current block is not coded in the skip mode.
10. The decoder of claim 9 , wherein:
the prediction mode includes intra prediction mode and inter prediction mode, and
the motion vector predictor of the current block is derived when the prediction mode information specifies the prediction mode of the current block is the inter prediction mode.
11. The decoder of claim 7 , wherein the one or more storage devices store instructions that are operable, when executed by the one or more processors, to cause the one or more processors to perform operations comprising:
obtaining a motion vector difference of the current block;
deriving a motion vector of the current block by using the motion vector difference of the current block and the motion vector predictor of the current block,
wherein the pixel value of the current block is predicted by motion compensation using the motion vector of the current block.
12. The decoder of claim 11 , wherein the motion vector difference of the current block is a difference vector between the motion vector of the current block and the motion vector predictor of the current block.