Intra-prediction apparatus for removing a directional intra-prediction mode from a set of predetermined directional intra-prediction modes
An intra-prediction method includes: determining, by an intra-prediction apparatus, a directional intra-prediction mode for a rectangular video coding block from an extended set of directional intra-prediction modes, wherein the extended set of directional intra-prediction modes includes extended directional intra-prediction modes and conventional directional intra-prediction modes and determining, by the intra-prediction apparatus, a plurality of available reference samples based on a direction of the directional intra-prediction mode. The method further includes: intra-predicting, by the intra-prediction apparatus, pixel values of pixels of the rectangular video coding block based on the plurality of available reference samples.
1 . An intra-prediction method, comprising:
obtaining, by an intra-prediction apparatus, a first directional intra-prediction mode;
determining, by the intra-prediction apparatus, for a rectangular video coding block, a second directional intra-prediction mode based on the first directional intra-prediction mode, wherein the rectangular video coding block has a first side and a second side, and wherein a length of the first side is different from a length of the second side; and
intra-predicting, by the intra-prediction apparatus, pixel values of pixels of the rectangular video coding block based on the second directional intra-prediction mode, wherein intra-predicting the pixel values of the pixels of the rectangular video coding block uses a first number of reference samples along the first side and a second number of reference samples along the second side, wherein the first number and the second number are different.
2 . The intra-prediction method of claim 1 , wherein an angle of the first directional intra-prediction mode is within a range [−45°, 135°], and an angle of the second directional intra-prediction mode is beyond the range [−45°, 135°].
3 . The intra-prediction method of claim 1 , wherein determining the second directional intra-prediction mode for the rectangular video coding block is further based on an aspect ratio of the rectangular video coding block.
4 . The intra-prediction method of claim 3 , wherein the second side of the rectangular video coding block is longer than the first side of the rectangular video coding block, and wherein the aspect ratio of the rectangular video coding block is
R
asp
=
L
shorter
L
longer
,
where L shorter and L longer are the lengths of the first and second sides of the rectangular video coding block, respectively.
5 . The intra-prediction method of claim 1 , wherein the rectangular video coding block is a coding unit, a prediction unit, or a transform unit.
6 . The intra-prediction method of claim 1 , wherein the first directional intra-prediction mode is applicable to both square video coding blocks and non-square rectangular video coding blocks, and wherein the second directional intra-prediction mode is applicable to non-square rectangular video coding blocks.
7 . The intra-prediction method of claim 6 , wherein the second directional intra-prediction mode is not applicable to square video coding blocks.
8 . An intra-prediction apparatus, comprising:
a non-transitory computer-readable storage medium storing instructions; and
one or more processors in communication with the non-transitory computer-readable storage medium, wherein the one or more processors are configured to execute the instructions to facilitate the following being performed by the apparatus:
obtaining a first directional intra-prediction mode;
determining, for a rectangular video coding block, a second directional intra-prediction mode based on the first directional intra-prediction mode, wherein the rectangular video coding block has a first side and a second side, and wherein a length of the first side is different from a length of the second side; and
intra-predicting pixel values of pixels of the rectangular video coding block based on the second directional intra-prediction mode, wherein intra-predicting the pixel values of the pixels of the rectangular video coding block uses a first number of reference samples along the first side and a second number of reference samples along the second side, wherein the first number and the second number are different.
9 . The intra-prediction apparatus of claim 8 , wherein an angle of the first directional intra-prediction mode is within a range [−45°, 135°], and an angle of the second directional intra-prediction mode is beyond the range [−45°, 135°].
10 . The intra-prediction apparatus of claim 8 , wherein
determining the second directional intra-prediction mode for the rectangular video coding block is further based on an aspect ratio of the rectangular video coding block.
11 . The intra-prediction apparatus of claim 10 , wherein the second side of the rectangular video coding block is longer than the first side of the rectangular video coding block, and wherein the aspect ratio of the rectangular video coding block is
R
asp
=
L
shorter
L
longer
,
where L shorter and L longer are the lengths of the first and second sides of the rectangular video coding block, respectively.
12 . The intra-prediction apparatus of claim 8 , wherein the first directional intra-prediction mode is applicable to both square video coding blocks and non-square rectangular video coding blocks, and wherein the second directional intra-prediction mode is applicable to non-square rectangular video coding blocks.
13 . The intra-prediction apparatus of claim 12 , wherein the second directional intra-prediction mode is not applicable to square video coding blocks.
14 . The intra-prediction apparatus of claim 8 , wherein the rectangular video coding block is a coding unit, a prediction unit, or a transform unit.
15 . The intra-prediction apparatus of claim 8 , wherein the apparatus is a decoder or an encoder.
16 . A non-transitory computer readable medium having processor-executable instructions stored thereon for intra-prediction, wherein the processor-executable instructions, when executed, facilitate:
obtaining a first directional intra-prediction mode;
determining, for a rectangular video coding block, a second directional intra-prediction mode based on the first directional intra-prediction mode, wherein the rectangular video coding block has a first side and a second side, and wherein a length of the first side is different from a length of the second side; and
intra-predicting pixel values of pixels of the rectangular video coding block based on the second directional intra-prediction mode, wherein intra-predicting the pixel values of the pixels of the rectangular video coding block uses a first number of reference samples along the first side and a second number of reference samples along the second side, wherein the first number and the second number are different.
17 . The non-transitory computer readable medium of claim 16 , wherein an angle of the first directional intra-prediction mode is within a range [−45°, 135°], and an angle of the second directional intra-prediction mode is beyond the range [−45°, 135°].
18 . The non-transitory computer readable medium of claim 16 , wherein determining the second directional intra-prediction mode for the rectangular video coding block is further based on an aspect ratio of the rectangular video coding block.
19 . The non-transitory computer readable medium of claim 18 , wherein the second side of the rectangular video coding block is longer than the first side of the rectangular video coding block, and wherein the aspect ratio of the rectangular video coding block is
R
asp
=
L
shorter
L
longer
,
where L shorter and L longer are the lengths of the first and second sides of the rectangular video coding block, respectively.
20 . The non-transitory computer readable medium of claim 16 , wherein the first directional intra-prediction mode is applicable to both square video coding blocks and non-square rectangular video coding blocks, and wherein the second directional intra-prediction mode is applicable to non-square rectangular video coding blocks.