Method and apparatus for line buffer reduction for video processing

1. A method for context adaptive entropy decoding, the method comprising:

receiving coded data associated with a current block in a region, wherein the region corresponds to one or more rows of largest coding units (LCUs) and the coded data comprises a syntax element associated with a current luma intra mode of the current block;

if a neighboring block of the current block is on an upper side of a horizontal boundary of the region or on a left side of a vertical boundary of the region, replacing block information associated with the neighboring block by DC mode;

determining information for parsing the syntax element based on the block information associated with the neighboring blocks; and

performing context adaptive entropy decoding of the syntax element based on the determined information.

2. The method of claim 1 , wherein the context adaptive entropy decoding corresponds to CABAC (context adaptive binary arithmetic coding) decoding or CAVLC (context adaptive variable length coding) decoding.

3. The method of claim 1 , wherein the syntax element corresponds to luma intra mode, significant flag, last significant flag, coefficient greater than one, or coefficient magnitude minus one.

4. The method of claim 3 , wherein the replacement block information corresponds to DC mode or Planar mode when the syntax element corresponds to the luma intra mode.

5. The method of claim 1 , wherein the replacement block information corresponds to a pre-defined value, a user-defined value, a value that marked as unavailable, or the block information of a previously processed block in the region.

6. The method of claim 5 , wherein the previously processed block is a left block or a lower-left block of the current block.

7. The method of claim 1 , wherein the block information includes the syntax element to be processed by the context adaptive entropy decoding.

8. The method of claim 1 wherein said one or more neighboring blocks correspond to one or more blocks selected from a group consisting of an above-left block, an above block, an above-right block, a left block and an above left block of the current block.

9. The method of claim 1 , wherein said one or more neighboring blocks correspond to an above block and a left block of the current block.

10. An apparatus for context adaptive entropy decoding, the apparatus comprising one or more electronic circuits configured to:

receive coded data associated with a current block in a region, wherein the region corresponds to one or more rows of largest coding units (LCUs) and the coded data comprises a syntax element associated with a current luma intra mode of the current block;

if a neighboring block of the current block is on an upper side of a horizontal boundary of the region or on a left side of a vertical boundary of the region, replace block information associated with the neighboring block by DC mode;

determine information for parsing the syntax element based on the block information associated with the neighboring blocks; and

perform context adaptive entropy decoding of the syntax element based on the determined information.

11. The apparatus of claim 10 , wherein the context adaptive entropy decoding corresponds to CABAC (context adaptive binary arithmetic coding) decoding or CAVLC (context adaptive variable length coding) decoding.

12. The apparatus of claim 10 , wherein the syntax element corresponds to luma intra mode, significant flag, last significant flag, coefficient greater than one, or coefficient magnitude minus one.

13. The apparatus of claim 12 , wherein the replacement block information corresponds to DC mode or Planar mode when the syntax element corresponds to the luma intra mode.

14. The apparatus of claim 10 , wherein the replacement block information corresponds to a pre-defined value, a user-defined value, a value that marked as unavailable, or the block information of a previously processed block in the region.

15. The apparatus of claim 14 , wherein the previously processed block is a left block or a lower-left block of the current block.

16. The apparatus of claim 10 , wherein the block information includes the syntax element to be processed by the context adaptive entropy decoding.

17. The apparatus of claim 10 wherein said one or more neighboring blocks correspond to one or more blocks selected from a group consisting of an above-left block, an above block, an above-right block, a left block and an above left block of the current block.

18. The apparatus of claim 10 , wherein said one or more neighboring blocks correspond to an above block and a left block of the current block.

19. A non-transitory computer readable medium storing a computer-executable program, the computer-executable program, when executed, causing a decoder to perform the following steps:

receiving coded data associated with a current block in a region, wherein the region corresponds to one or more rows of largest coding units (LCUs) and the coded data comprises a syntax element associated with a current luma intra mode of the current block;

if a neighboring block of the current block is on an upper side of a horizontal boundary of the region or on a left side of a vertical boundary of the region, replacing block information associated with the neighboring block by DC mode;

determining information for parsing the syntax element based on the block information associated with the neighboring blocks; and

performing context adaptive entropy decoding of the syntax element based on the determined information.