Filters for motion compensation interpolation with reference down-sampling
The present disclosure provides systems and methods for processing video content using motion compensation interpolation. The methods include: encoding or decoding a picture block by applying one or more filters to a reference picture, wherein the applying of the one or more filters generates a sample at a fractional sample position, and wherein the one or more filters comprise an 8-tap filter that has a plurality of coefficients [p0, p1, . . . , p7] for each 1/16 fractional sample position p.
1. A computer-implemented method for processing video content, comprising:
encoding or decoding a picture block by applying one or more filters to a reference picture,
wherein the applying of the one or more filters generates a sample at a fractional sample position, and
wherein the one or more filters comprise an 8-tap filter that has a plurality of coefficients [p0, p1, . . . , p7] for each 1/16 fractional sample position p, as the following:
Fractional
sample position
Coefficients
p
p0
p1
p2
p3
p4
p5
p6
p7
0
−4
2
20
28
20
2
−4
0
1
−4
0
19
29
21
5
−4
−2
2
−4
−1
18
29
22
6
−4
−2
3
−4
−1
16
29
23
7
−4
−2
4
−4
−1
16
28
24
7
−4
−2
5
−4
−1
14
28
25
8
−4
−2
6
−3
−3
14
27
26
9
−3
−3
7
−3
−1
12
28
25
10
−4
−3
8
−3
−3
11
27
27
11
−3
−3
9
−3
−4
10
25
28
12
−1
−3
10
−3
−3
9
26
27
14
−3
−3
11
−2
−4
8
25
28
14
−1
−4
12
−2
−4
7
24
28
16
−1
−4
13
−2
−4
7
23
29
16
−1
−4
14
−2
−4
6
22
29
18
−1
−4
15
−2
−4
5
21
29
19
0
−4.
2. The method according to claim 1 , wherein the sample is a luma sample.
3. The method according to claim 1 , wherein the one or more filters comprise a 4-tap filter that has a plurality of coefficients [p0, p1, p2, p3] for each 1/p fractional sample position p, as the following:
Fractional sample
position
Coefficients
p
p0
p1
p2
p3
0
17
30
17
0
1
17
30
18
−1
2
16
30
18
0
3
16
30
18
0
4
15
30
18
1
5
14
30
18
2
6
13
29
19
3
7
13
29
19
3
8
12
29
20
3
9
11
28
21
4
10
10
28
22
4
11
10
27
22
5
12
9
27
23
5
13
9
26
24
5
14
8
26
24
6
15
7
26
25
6
16
7
25
25
7
17
6
25
26
7
18
6
24
26
8
19
5
24
26
9
20
5
23
27
9
21
5
22
27
10
22
4
22
28
10
23
4
21
28
11
24
3
20
29
12
25
3
19
29
13
26
3
19
29
13
27
2
18
30
14
28
1
18
30
15
29
0
18
30
16
30
0
18
30
16
31
−1
18
30
17.
4. The method according to claim 3 , wherein the sample is a chroma sample.
5. The method according to claim 1 , wherein the plurality of coefficients is signaled in at least one of a Sequence Parameter Set (SPS), a Picture Parameter Set (PPS), an Adaptation Parameter Set (APS), or a slice header.
6. The method according to claim 1 , wherein applying the one or more filters comprises:
selecting the one or more filter, based on a sampling ratio of the reference picture.
7. A system for processing video content, comprising:
a memory for storing a set of instructions; and
at least one processor configured to execute the set of instructions to cause the system to perform:
encoding or decoding a picture block by applying one or more filters to a reference picture,
wherein the applying of the one or more filters generates a sample at a fractional sample position, and
wherein the one or more filters comprise an 8-tap filter that has a plurality of coefficients [p0, p1, . . . , p7] for each 1/16 fractional sample position p, as the following:
Fractional
sample
Coefficients
position p
p0
p1
p2
p3
p4
p5
p6
p7
0
−4
2
20
28
20
2
−4
0
1
−4
0
19
29
21
5
−4
−2
2
−4
−1
18
29
22
6
−4
−2
3
−4
−1
16
29
23
7
−4
−2
4
−4
−1
16
28
24
7
−4
−2
5
−4
−1
14
28
25
8
−4
−2
6
−3
−3
14
27
26
9
−3
−3
7
−3
−1
12
28
25
10
−4
−3
8
−3
−3
11
27
27
11
−3
−3
9
−3
−4
10
25
28
12
−1
−3
10
−3
−3
9
26
27
14
−3
−3
11
−2
−4
8
25
28
14
−1
−4
12
−2
−4
7
24
28
16
−1
−4
13
−2
−4
7
23
29
16
−1
−4
14
−2
−4
6
22
29
18
−1
−4
15
−2
−4
5
21
29
19
0
−4
8. The system according to claim 7 , wherein the sample is a luma sample.
9. The system according to claim 7 , wherein the one or more filters comprise a 4-tap filter that has a plurality of coefficients [p0, p1, p2, p3] for each 1/p fractional sample position p, as the following:
Fractional sample
position
Coefficients
p
p0
p1
p2
p3
0
17
30
17
0
1
17
30
18
−1
2
16
30
18
0
3
16
30
18
0
4
15
30
18
1
5
14
30
18
2
6
13
29
19
3
7
13
29
19
3
8
12
29
20
3
9
11
28
21
4
10
10
28
22
4
11
10
27
22
5
12
9
27
23
5
13
9
26
24
5
14
8
26
24
6
15
7
26
25
6
16
7
25
25
7
17
6
25
26
7
18
6
24
26
8
19
5
24
26
9
20
5
23
27
9
21
5
22
27
10
22
4
22
28
10
23
4
21
28
11
24
3
20
29
12
25
3
19
29
13
26
3
19
29
13
27
2
18
30
14
28
1
18
30
15
29
0
18
30
16
30
0
18
30
16
31
−1
18
30
17.
10. The system according to claim 9 , wherein the sample is a chroma sample.
11. The system according to claim 7 , wherein the plurality of coefficients is signaled in at least one of a Sequence Parameter Set (SPS), a Picture Parameter Set (PPS), an Adaptation Parameter Set (APS), or a slice header.
12. The system according to claim 7 , wherein in applying the one or more filters, the at least one processor is configured to execute the set of instructions to cause the system to perform:
selecting the one or more filter, based on a sampling ratio of the reference picture.
13. A method of storing a bitstream of a video, the method comprising:
applying one or more filters to a reference picture, wherein the applying of the one or more filters generates a sample at a fractional sample position;
generating a bitstream comprising coded information representing the sample at the fractional sample position; and
storing the bitstream in a non-transitory computer readable medium,
wherein the one or more filters comprise an 8-tap filter that has a plurality of coefficients [p0, p1, . . . , p7] for each 1/16 fractional sample position p, as the following:
Fractional
sample position
Coefficients
p
p0
p1
p2
p3
p4
p5
p6
p7
0
−4
2
20
28
20
2
−4
0
1
−4
0
19
29
21
5
−4
−2
2
−4
−1
18
29
22
6
−4
−2
3
−4
−1
16
29
23
7
−4
−2
4
−4
−1
16
28
24
7
−4
−2
5
−4
−1
14
28
25
8
−4
−2
6
−3
−3
14
27
26
9
−3
−3
7
−3
−1
12
28
25
10
−4
−3
8
−3
−3
11
27
27
11
−3
−3
9
−3
−4
10
25
28
12
−1
−3
10
−3
−3
9
26
27
14
−3
−3
11
−2
−4
8
25
28
14
−1
−4
12
−2
−4
7
24
28
16
−1
−4
13
−2
−4
7
23
29
16
−1
−4
14
−2
−4
6
22
29
18
−1
−4
15
−2
−4
5
21
29
19
0
−4.
14. The method according to claim 13 , wherein the sample is a luma sample.
15. The method according to claim 13 , wherein the one or more filters comprise a 4-tap filter that has a plurality of coefficients [p0, p1, p2, p3] for each 1/p fractional sample position p, as the following:
Fractional sample
position
Coefficients
p
p0
p1
p2
p3
0
17
30
17
0
1
17
30
18
−1
2
16
30
18
0
3
16
30
18
0
4
15
30
18
1
5
14
30
18
2
6
13
29
19
3
7
13
29
19
3
8
12
29
20
3
9
11
28
21
4
10
10
28
22
4
11
10
27
22
5
12
9
27
23
5
13
9
26
24
5
14
8
26
24
6
15
7
26
25
6
16
7
25
25
7
17
6
25
26
7
18
6
24
26
8
19
5
24
26
9
20
5
23
27
9
21
5
22
27
10
22
4
22
28
10
23
4
21
28
11
24
3
20
29
12
25
3
19
29
13
26
3
19
29
13
27
2
18
30
14
28
1
18
30
15
29
0
18
30
16
30
0
18
30
16
31
−1
18
30
17.
16. The method according to claim 15 , wherein the sample is a chroma sample.
17. The method according to claim 13 , wherein the coded information comprises a Sequence Parameter Set (SPS), a Picture Parameter Set (PPS), an Adaptation Parameter Set (APS), and a slice header, the plurality of coefficients being signaled in at least one of the SPS, PPS, APS, or slice header.
18. The method according to claim 13 , wherein applying the one or more filters comprises:
selecting the one or more filter, based on a sampling ratio of the reference picture.