Method and an apparatus for processing a video signal
The present invention relates to a video signal decoding method for adding an intra prediction mode as a sub-macroblock type to prediction of a macroblock in coding a video signal. Some implementations may include obtaining a macroblock type, when a macroblock includes the intra prediction coded sub-macroblock and the inter prediction coded sub-macroblock based on the macroblock type, obtaining prediction mode flag information indicating whether the sub-macroblock is the intra prediction coded or the inter prediction coded, and obtaining a prediction value of the sub-macroblock. Accordingly, implementations disclosed herein may raise coding efficiency of video signal by adding an intra prediction mode as a sub-macroblock type in predicting a macroblock.
1. A method for decoding a bitstream by a video decoding apparatus, the method comprising:
obtaining, by the video decoding apparatus from the bitstream, first information for a current block, the first information specifying whether the bitstream contains transform coefficient information for the current block;
determining, based on the first information, whether to obtain second information for a sub-block of the current block, the second information of the sub-block specifying whether the bitstream contains transform coefficient information for the sub-block;
obtaining, by the video decoding apparatus from the bitstream, the second information for the sub-block of the current block based on the first information having a first value;
obtaining, by the video decoding apparatus from the bitstream, the transform coefficient information for the sub-block based on the second information of the sub-block having the first value;
obtaining, by the video decoding apparatus, residual data of the sub-block based on the obtained transform coefficient information;
obtaining, by the video decoding apparatus, a predicted value of the sub-block based on an intra-prediction; and
reconstructing, by the video decoding apparatus, the sub block based on the obtained residual data and the predicted value,
wherein, based on the first information having a second value, the obtaining the second information for the sub-block of the current block is skipped.
2. The method according to claim 1 , wherein the first value is 1.
3. The method according to claim 1 , wherein the bitstream contains no transform coefficient information for the current block based on the first information having the second value.
4. The method according to claim 1 , wherein the bitstream contains no transform coefficient information for the sub block based on the second information of the sub-block having the second value.
5. The method according to claim 3 , wherein the second value is 0.
6. The method according to claim 1 , wherein the current block is partitioned into a plurality of sub-blocks based on a transform block unit for performing an inverse-transform operation.
7. The method according to claim 1 , wherein the current block has a size equal to or greater than 32×32.
8. A video decoding apparatus configured to decode a bitstream, the video decoding apparatus comprising:
an entropy decoding unit configured to:
obtain, from the bitstream, first information for a current block, the first information specifying whether the bitstream contains transform coefficient information for the current block,
determine, based on the first information, whether to obtain second information for a sub-block of the current block, the second information of the sub-block specifying whether the bitstream contains transform coefficient information for the sub-block,
obtain, from the bitstream, the second information for the sub-block of the current block based on the first information having a first value, and
obtain, from the bitstream, the transform coefficient information for the sub-block based on the second information of the sub-block having the first value;
obtain, a predicted value of the sub-block based on an intra-prediction; and
an inverse-transform unit configured to:
obtain residual data of the sub-block based on the obtained transform coefficient information, and
reconstruct the sub-block based on the obtained residual data and the predicted value,
wherein, based on the first information having a second value, obtaining the second information for the sub-block of the current block is skipped.
9. The video decoding apparatus according to claim 8 , wherein the first value is 1.
10. The video decoding apparatus according to claim 8 , wherein the bitstream contains no transform coefficient information for the current block based on the first information having the second value.
11. The video decoding apparatus according to claim 8 , wherein the bitstream contains no transform coefficient information for the sub-block based on the second information of the sub-block having the second value.
12. The video decoding apparatus according to claim 10 , wherein the second value is 0.
13. The video decoding apparatus according to claim 8 , wherein the current block is partitioned into a plurality of sub-blocks based on a transform block unit for performing an inverse-transform operation.
14. The video decoding apparatus according to claim 8 , wherein the current block has a size equal to or greater than 32×32.
15. A method for encoding a bitstream by a video encoding apparatus, the method comprising:
encoding, by the video encoding apparatus into the bitstream, first information for a current block, the first information specifying whether the bitstream contains transform coefficient information for the current block;
determining, based on the first information, whether to encode second information for a sub-block of the current block, the second information of the sub-block specifying whether the bitstream contains transform coefficient information for the sub-block;
encoding, by the video encoding apparatus into the bit stream, the second information for the sub-block of the current block based on the first information having a first value;
encoding, by the video encoding apparatus into the bitstream, the transform coefficient information for the sub-block based on the second information of the sub-block having the first value;
obtaining, by the video encoding apparatus, residual data of the sub-block based on the encoded transform coefficient information;
obtaining, by the video encoding apparatus, a predicted value of the sub-block based on an intra-prediction; and
reconstructing, by the video encoding apparatus, the sub block based on the obtained residual data and the predicted value,
wherein, based on the first information having a second value, the second information for the sub-block of the current block is not encoded.
16. A non-transitory computer readable storage medium storing the bitstream encoded by the method of claim 15 .
17. A video encoding apparatus configured to encode a bitstream, the video encoding apparatus comprising:
an entropy coding unit configured to:
encode, into the bitstream, first information for a current block, the first information specifying whether the bitstream contains transform coefficient information for the current block,
determine, based on the first information, whether to encode second information for a sub-block of the current block, the second information of the sub-block specifying whether the bitstream contains transform coefficient information for the sub-block,
encode, into the bitstream, the second information for the sub-block of the current block based on the first information having a first value, and
encode, into the bitstream, the transform coefficient information for the sub-block based on the second information of the sub-block having the first value
obtain, a predicted value of the sub-block based on an intra-prediction; and
an inverse-transform unit configured to:
obtain residual data of the sub-block based on the encoded transform coefficient information, and
reconstruct the sub-block based on the obtained residual data and the predicted value,
wherein, based on the first information having a second value, the second information for the sub-block of the current block is not encoded.