METHOD AND APPARATUS FOR NON-CROSS-TILE LOOP FILTERING
A method and apparatus for loop filter processing of video data are disclosed. Embodiments according to the present invention eliminate data dependency associated with loop processing across tile boundaries. According to one embodiment, loop processing is reconfigured to eliminate data dependency across tile boundaries if cross-tile loop processing is disabled. The loop filter processing corresponds to DF (deblocking filter), SAO (Sample Adaptive Offset) processing or ALF (Adaptive Loop Filter) processing. The processing can be skipped for at least one tile boundary. In another embodiment, data padding based on the pixels of the current tile or modifying pixel classification footprint are used to eliminate data dependency across the tile boundary. Whether cross-tile loop processing is disabled can be indicated by a flag coded at sequence, picture, or slice level to indicate whether the data dependency across said at least one tile boundary is allowed.
1 . A method for loop filter processing of video data, the method comprising:
receiving video data associated with a picture, wherein the picture is partitioned into one or more tiles;
determining tile boundaries associated with said one or more tiles;
determining whether cross-tile loop processing is disabled;
reconfiguring the loop filter processing if the cross-tile loop processing is disabled, wherein said reconfiguring the loop filter processing eliminates data dependency across at least one tile boundary of a current tile if the loop filter processing requires at least one pixel from a neighboring tile across said at least one tile boundary; and
applying the loop filter processing to said one or more tiles.
2 . The method of claim 1 , wherein said reconfiguring the loop filter processing corresponds to skipping the loop filter processing, replacing said at least one pixel from the neighboring tile across said at least one tile boundary using data padding based on the pixels of the current tile, or modifying data footprint or filter footprint to eliminate data dependency across said at least one tile boundary.
3 . The method of claim 1 , wherein the loop filter processing corresponds to DF (deblocking filter), SAO (Sample Adaptive Offset) processing or ALF (Adaptive Loop Filter) processing.
4 . The method of claim 1 , wherein the loop filter processing corresponds to DF, and wherein the loop filter processing is skipped for said at least one tile boundary.
5 . The method of claim 1 , wherein the loop filter processing corresponds to SAO, and wherein said reconfiguring the loop filter processing corresponds to skipping the loop filter processing for said at least one tile boundary, replacing said at least one pixel from the neighboring tile across said at least one tile boundary using data padding based on the pixels of the current tile, or modifying pixel classification footprint to eliminate data dependency across said at least one tile boundary.
6 . The method of claim 5 , wherein said data padding corresponds to repetitive padding, mirror padding with odd symmetry, mirror based padding with even symmetry, linear extrapolation or nonlinear extrapolation.
7 . The method of claim 1 , wherein the loop filter processing corresponds to ALF, and wherein said reconfiguring the loop filter processing corresponds to skipping the loop filter processing for said at least one tile boundary, replacing said at least one pixel from the neighboring tile across said at least one tile boundary using data padding based on the pixels of the current tile, or modifying filter footprint to eliminate data dependency across said at least one tile boundary.
8 . The method of claim 7 , wherein said data padding corresponds to repetitive padding, mirror padding with odd symmetry, mirror based padding with even symmetry, linear extrapolation or nonlinear extrapolation.
9 . The method of claim 1 , wherein said determining whether cross-tile loop processing is disabled is indicated by a flag, wherein the flag is coded at sequence, picture, or slice level to indicate whether data dependency across said at least one tile boundary is allowed.
10 . The method of claim 9 , wherein the flag is coded if said one or more tiles are more than one and otherwise the flag is not coded.
11 . A method for loop filter processing of video data, the method comprising:
receiving video data associated with a picture, wherein the picture is partitioned into one or more tiles;
determining tile boundaries associated with said one or more tiles;
determining filter information for said one or more tiles, wherein said determining filter information is modified to eliminate first data dependency across at least one first tile boundary of a current tile if said determining filter information requires at least one pixel from a first neighboring tile across said at least one first tile boundary; and
applying the loop filter processing to said one or more tiles using the filter information, wherein the loop filter processing is reconfigured to eliminate second data dependency across at least one second tile boundary of the current tile if the loop filter processing requires at least one pixel from a second neighboring tile across said at least one second tile boundary.
12 . The method of claim 11 , wherein said reconfiguring the loop filter processing corresponds to skipping the loop filter processing, replacing said at least one pixel from the neighboring tile across said at least one tile boundary using data padding based on the pixels of the current tile, or modifying data footprint or filter footprint to eliminate data dependency across said at least one tile boundary.
13 . The method of claim 11 , wherein the loop filter processing corresponds to DF (deblocking filter), SAO (Sample Adaptive Offset) processing or ALF (Adaptive Loop Filter) processing.
14 . The method of claim 13 , wherein the loop filter processing corresponds to DF, and wherein the loop filter processing is skipped for said at least one second tile boundary.
15 . The method of claim 13 , wherein the loop filter processing corresponds to SAO, and wherein said reconfiguring the loop filter processing corresponds to skipping the loop filter processing for said at least one tile boundary, replacing said at least one pixel from the neighboring tile across said at least one second tile boundary using data padding based on the pixels of the current tile, or modifying pixel classification footprint to eliminate data dependency across said at least one tile boundary.
16 . The method of claim 15 , wherein said data padding corresponds to repetitive padding, mirror padding with odd symmetry, mirror based padding with even symmetry, linear extrapolation or nonlinear extrapolation.
17 . The method of claim 13 , wherein the loop filter processing corresponds to ALF, and wherein said reconfiguring the loop filter processing corresponds to skipping the loop filter processing for said at least one second tile boundary, replacing said at least one pixel from the neighboring tile across said at least one second tile boundary using data padding based on the pixels of the current tile, or modifying filter footprint to eliminate data dependency across said at least one second tile boundary.
18 . The method of claim 17 , wherein said data padding corresponds to repetitive padding, mirror padding with odd symmetry, mirror based padding with even symmetry, linear extrapolation or nonlinear extrapolation.
19 . The method of claim 11 , wherein a flag is coded at sequence, picture, or slice level to indicate whether data dependency across said at least one second tile boundary is allowed.
20 . The method of claim 19 , wherein the flag is coded if said one or more tiles are more than one and otherwise the flag is not coded.
21 . An apparatus for loop filter processing of video data in a video decoder, the apparatus comprising:
means for receiving video data associated with a picture, wherein the picture is partitioned into one or more tiles;
means for determining tile boundaries associated with said one or more tiles;
means for determining whether cross-tile loop processing is disabled;
means for reconfiguring the loop filter processing if the cross-tile loop processing is disabled, wherein said means for reconfiguring the loop filter processing eliminates data dependency across at least one tile boundary of a current tile if the loop filter processing requires at least one pixel from a neighboring tile across said at least one tile boundary; and
means for applying the loop filter processing to said one or more tiles.
22 . An apparatus for loop filter processing of video data, the apparatus comprising:
means for receiving video data associated with a picture, wherein the picture is partitioned into one or more tiles;
means for determining tile boundaries associated with said one or more tiles;
means for determining filter information for said one or more tiles, wherein said determining filter information is modified to eliminate first data dependency across at least one first tile boundary of a current tile if said determining filter information requires at least one pixel from a first neighboring tile across said at least one first tile boundary; and
means for applying the loop filter processing to said one or more tiles using the filter information, wherein the loop filter processing is reconfigured to eliminate second data dependency across at least one second tile boundary of the current tile if the loop filter processing requires at least one pixel from a second neighboring tile across said at least one second tile boundary.