# US 10,771,782 B2 · Method and apparatus for video coding

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,771,782 B2
- Document ID: US10771782B2
- Status: Granted
- Kind: B2
- Application number: 16/359,631
- Filed: 2019-03-20
- Published: 2020-01-02
- Granted: 2020-09-08
- Earliest claimed: 2018-07-02
- Assignees: Tencent America LLC
- Applicants: Tencent America LLC
- Inventors: Xin Zhao; Liang Zhao; Shan Liu; Xiang Li
- Web page: https://patentgrep.com/patent/US10771782B2

## CPC

- H04N 19/11: among a plurality of spatial predictive coding modes
- H04N 19/176: the region being a block, e.g. a macroblock
- H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards
- H04N 19/91: Entropy coding, e.g. variable length coding [VLC] or arithmetic coding
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

Method and decoder for reconstructing at least a sample of a block using an intra prediction angle determined from an intra prediction mode. The method includes decoding at least one syntax element from a coded video sequence. The at least one syntax element is indicative of an intra prediction mode. An intra prediction angle is determined that corresponds to the indicated intra prediction mode based on a stored relationship between a plurality of intra prediction modes and a plurality of intra prediction angles. At least one sample of a block is reconstructed using the intra prediction angle that is determined to correspond to the indicated intra prediction mode. The plurality of intra prediction modes in the stored relationship can include at least one of a first plurality of wide angle prediction modes and a second plurality of wide angle prediction modes. The first plurality of wide angle prediction modes is beyond a bottom left direction diagonal mode and the second plurality of wide angle prediction modes is beyond a top right direction diagonal mode.

## Claims

### Claim 1

A method for video decoding in a video decoder, the method comprising:
decoding a coded video sequence to obtain an intra prediction mode;
determining an intra prediction angle that corresponds to the intra prediction mode based on a predetermined plurality of intra prediction modes and a corresponding predetermined plurality of intra prediction angles; and
reconstructing at least one sample of a block using the intra prediction angle that is determined to correspond to the indicated intra prediction mode, wherein
the plurality of intra prediction modes includes at least one of a first plurality of wide angle prediction modes and a second plurality of wide angle prediction modes,
the first plurality of wide angle prediction modes is beyond a bottom left direction diagonal mode, and
the second plurality of wide angle prediction modes is beyond a top right direction diagonal mode.

### Claim 2 (depends on 1)

The method recited in claim 1, wherein the predetermined plurality of intra prediction modes and corresponding predetermined plurality of intra prediction angles are in a stored relationship as a look-up table.

### Claim 3 (depends on 2)

The method recited in claim 2, wherein
the intra prediction angle corresponds to intraPredAngle and the intra prediction mode corresponds to predModeIntra, and
the stored relationship is in accordance with:
predModeIntra
−10
−9
−8
−7
−6
−5
−4
−3
−2
−1
2
3
4
5
6
7
8
intraPredAngle
114
93
79
68
60
54
49
45
39
35
32
29
26
23
21
19
17
predModeIntra
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
intraPredAngle
15
13
11
9
7
5
3
2
1
0
−1
−2
−3
−5
−7
−9
−11
predModeIntra
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
intraPredAngle
−13
−25
−17
−19
−21
−23
−26
−29
−32
−29
−26
−23
−21
−19
−17
−15
−13
predModeIntra
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
intraPredAngle
−11
−9
−7
−5
−3
−2
−1
0
1
2
3
5
7
9
11
13
15
predModeIntra
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
intraPredAngle
17
19
21
23
26
29
32
35
39
45
49
54
60
68
79
93
114.

### Claim 4 (depends on 3)

The method recited in claim 3, wherein the reconstructing comprises:
reconstructing the at least one sample of a non-square block using the relationship between predModeIntra and intraPredAngle.

### Claim 5 (depends on 2)

The method recited in claim 2, wherein the reconstructing comprises:
reconstructing the at least one sample of a non-square block using the stored relationship between the plurality of intra prediction modes and the plurality of intra prediction angles.

### Claim 6 (depends on 1)

The method recited in claim 1, wherein
a number of the first plurality of wide angle prediction modes is ten; and
a number of the second plurality of wide angle prediction modes is ten.

### Claim 7 (depends on 1)

The method recited in claim 1, wherein
the first plurality of wide angle prediction modes have integer values in a range of −1 to −10; and
the second plurality of wide angle prediction modes have integer values in a range of 67 to 76.

### Claim 8 (depends on 7)

The method recited in claim 7, wherein
the plurality of intra prediction angles corresponding to each of the first and second plurality of wide angle prediction modes are in a range of 35 to 114.

### Claim 9 (depends on 1)

The method recited in claim 1, wherein:
the first plurality of wide angle prediction modes go beyond mode 2 of the HEVC (High Efficiency Video Coding) standard; and
the second plurality of wide angle prediction modes go beyond mode 34 of the HEVC standard.

### Claim 10 (depends on 1)

The method recited in claim 1, comprising:
when a width W of the block is greater than a height H of the block,
the intra prediction angle is greater than ((32*H/W)+1), and
the intra prediction mode is less than 34,
modifying the intra prediction mode by adding 65 when the intra prediction angle is less than 9, and
setting the intra prediction mode to 66 when the intra prediction mode angle is at least 9.

### Claim 11 (depends on 1)

The method recited in claim 1, comprising:
when a width W of the block is less than a height H of the block,
the intra prediction angle is greater than ((32*W/H)+1), and
the intra prediction mode is greater than 34,
modifying the intra prediction mode by subtracting 67 when the intra prediction angle is greater than 9, and
setting the intra prediction mode to 2 when the intra prediction angle is 9 or less.

### Claim 12 (depends on 1)

The method recited in claim 1, comprising:
when a width W of the block is greater than a height H of the block,
the intra prediction angle is greater than ((32*H/W)+1), and
the intra prediction mode is less than 34,
modifying the intra prediction mode by adding 65 when the intra prediction angle is less than 9, and
modifying the intra prediction mode by subtracting the intra prediction mode from 68 when the intra prediction angle is at least 9.

### Claim 13 (depends on 1)

The method recited in claim 1, comprising:
when a width W of the block is less than a height H of the block,
the intra prediction angle is greater than ((32*W/H)+1), and
the intra prediction mode is greater than 34,
modifying the intra prediction mode by subtracting 67 when the intra prediction angle is greater than 9, and
modifying the intra prediction mode by subtracting the intra prediction mode from 68 when the intra prediction angle is 9 or less.

### Claim 14 (depends on 1)

The method recited in claim 1, comprising:
when a width W of the block is greater than a height H of the block,
the intra prediction angle is greater than ((32*H/W)+1), and
the intra prediction mode is less than 34,
modifying the intra prediction mode by adding 65 when the intra prediction angle is less than 9, and
setting the intra prediction mode to 76 when the intra prediction mode angle is at least 9.

### Claim 15 (depends on 1)

The method recited in claim 1, comprising:
when a width W of the block is less than a height H of the block,
the intra prediction angle is greater than ((32*W/H)+1), and
the intra prediction mode is greater than 34,
modifying the intra prediction mode by subtracting 67 when the intra prediction angle is greater than 9, and
setting the intra prediction mode to −10 when the intra prediction angle is 9 or less.

### Claim 16 (depends on 1)

The method recited in claim 1, comprising:
when a width W of the block is greater than a height H of the block,
the intra prediction angle is greater than ((32*H/W)+1), and
the intra prediction mode is less than 34,
modifying the intra prediction mode by adding 65 when the intra prediction angle is less than 9, and
modifying the intra prediction mode by subtracting the intra prediction mode from 68 when the intra prediction angle is 9 or less.

### Claim 17 (depends on 1)

The method recited in claim 1, comprising:
when a width W of the block is less than a height H of the block,
the intra prediction angle is greater than ((32*W/H)+1), and
the intra prediction mode is greater than 34,
modifying the intra prediction mode by subtracting 67 when the intra prediction angle is greater than 9, and
modifying the intra prediction mode by subtracting the intra prediction mode from 68 when the intra prediction angle is 9 or less.

### Claim 18

A video decoder for video decoding, comprising:
processing circuitry configured to:
decode a coded video sequence to obtain an intra prediction mode;
determine an intra prediction angle that corresponds to the intra prediction mode based on a predetermined plurality of intra prediction modes and a corresponding predetermined plurality of intra prediction angles; and
reconstruct at least one sample of a block using the intra prediction angle that is determined to correspond to the indicated intra prediction mode, wherein
the plurality of intra prediction modes includes at least one of a first plurality of wide angle prediction modes and a second plurality of wide angle prediction modes,
the first plurality of wide angle prediction modes is beyond a bottom left direction diagonal mode, and
the second plurality of wide angle prediction modes is beyond a top right direction diagonal mode.

### Claim 19 (depends on 18)

The video decoder recited in claim 18, wherein the predetermined plurality of intra prediction modes and corresponding predetermined plurality of intra prediction angles are in a stored relationship as a look-up table.

### Claim 20 (depends on 19)

The video decoder recited in claim 19, wherein
the intra prediction angle corresponds to intraPredAngle and the intra prediction mode corresponds to predModeIntra, and
the stored relationship is in accordance with:
predModeIntra
−10
−9
−8
−7
−6
−5
−4
−3
−2
−1
2
3
4
5
6
7
8
intraPredAngle
114
93
79
68
60
54
49
45
39
35
32
29
26
23
21
19
17
predModeIntra
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
intraPredAngle
15
13
11
9
7
5
3
2
1
0
−1
−2
−3
−5
−7
−9
−11
predModeIntra
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
intraPredAngle
−13
−25
−17
−19
−21
−23
−26
−29
−32
−29
−26
−23
−21
−19
−17
−15
−13
predModeIntra
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
intraPredAngle
−11
−9
−7
−5
−3
−2
−1
0
1
2
3
5
7
9
11
13
15
predModeIntra
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
intraPredAngle
17
19
21
23
26
29
32
35
39
45
49
54
60
68
79
93
114.

### Claim 21 (depends on 20)

The video decoder recited in claim 20, wherein the processing circuitry is configured to reconstruct the at least one sample of a non-square block using the relationship between predModeIntra and intraPredAngle.

### Claim 22 (depends on 19)

The video decoder recited in claim 19, wherein the processing circuitry is configured to reconstruct the at least one sample of a non-square block using the stored relationship between the plurality of intra prediction modes and the plurality of intra prediction angles.

### Claim 23 (depends on 18)

The video decoder recited in claim 18, wherein
a number of the first plurality of wide angle prediction modes is ten; and
a number of the second plurality of wide angle prediction modes is ten.

### Claim 24 (depends on 18)

The video decoder recited in claim 18, wherein
the first plurality of wide angle prediction modes have integer values in a range of −1 to −10; and
the second plurality of wide angle prediction modes have integer values in a range of 67 to 76.

### Claim 25 (depends on 24)

The video decoder recited in claim 24, wherein
the plurality of intra prediction angles corresponding to each of the first and second plurality of wide angle prediction modes are in a range of 35 to 114.

### Claim 26 (depends on 18)

The video decoder recited in claim 18, wherein:
the first plurality of wide angle prediction modes go beyond mode 2 of the HEVC (High Efficiency Video Coding) standard; and
the second plurality of wide angle prediction modes go beyond mode 34 of the HEVC standard.

### Claim 27

A non-transitory computer-readable medium storing instructions which when executed by a computer for video decoding cause the computer to perform:
decoding a coded video sequence to obtain an intra prediction mode;
determining an intra prediction angle that corresponds to the intra prediction mode based on a predetermined plurality of intra prediction modes and a corresponding predetermined plurality of intra prediction angles; and
reconstructing at least one sample of a block using the intra prediction angle that is determined to correspond to the indicated intra prediction mode, wherein
the plurality of intra prediction modes includes at least one of a first plurality of wide angle prediction modes and a second plurality of wide angle prediction modes,
the first plurality of wide angle prediction modes is beyond a bottom left direction diagonal mode, and
the second plurality of wide angle prediction modes is beyond a top right direction diagonal mode.

### Claim 28 (depends on 27)

The medium recited in claim 27, wherein the predetermined plurality of intra prediction modes and corresponding predetermined plurality of intra prediction angles are in a stored relationship as a look-up table.

### Claim 29 (depends on 28)

The medium recited in claim 28, wherein
the intra prediction angle corresponds to intraPredAngle and the intra prediction mode corresponds to predModeIntra, and
the stored relationship is in accordance with:
predModeIntra
−10
−9
−8
−7
−6
−5
−4
−3
−2
−1
2
3
4
5
6
7
8
intraPredAngle
114
93
79
68
60
54
49
45
39
35
32
29
26
23
21
19
17
predModeIntra
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
intraPredAngle
15
13
11
9
7
5
3
2
1
0
−1
−2
−3
−5
−7
−9
−11
predModeIntra
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
intraPredAngle
−13
−25
−17
−19
−21
−23
−26
−29
−32
−29
−26
−23
−21
−19
−17
−15
−13
predModeIntra
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
intraPredAngle
−11
−9
−7
−5
−3
−2
−1
0
1
2
3
5
7
9
11
13
15
predModeIntra
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
intraPredAngle
17
19
21
23
26
29
32
35
39
45
49
54
60
68
79
93
114.