# US 2020/0396455 A1 · Method and apparatus for video coding

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- Number: US 2020/0396455 A1
- Document ID: US20200396455A1
- Status: Published application
- Kind: A1
- Application number: 16/878,390
- Filed: 2020-05-19
- Published: 2020-12-17
- Earliest claimed: 2019-06-11
- Assignees: Tencent America LLC
- Applicants: Tencent America LLC
- Inventors: Shan LIU; Xin Zhao; Xiang Li
- Web page: https://patentgrep.com/patent/US20200396455A1

## CPC

- H04N 19/122: Selection of transform size, e.g. 8x8 or 2x4x8 DCT; Selection of sub-band transforms of varying structure or type
- H04N 19/159: Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
- H04N 19/176: the region being a block, e.g. a macroblock
- H04N 19/196: being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters (processing of motion vectors H04N19/513)
- H04N 19/593: involving spatial prediction techniques
- H04N 19/61: in combination with predictive coding
- H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

In a method of video decoding at a video decoder, a first high level syntax (HLS) element and a second HLS element can be received. The first HLS element can indicate whether an explicit multiple transform selection (MTS) is enabled or disabled for an intra coded block. The second HLS element can indicate whether the explicit MTS is enabled or disabled for an inter coded block. The first and second HLS elements can control a same set of coding blocks that include the intra coded block and the inter coded block. An implicit MTS can be enabled for the intra coded block when the first HLS element indicates the explicit MTS is disabled for the intra coded block, and the second HLS element indicates the explicit MTS is enabled for the inter coded block.

## Claims

### Claim 1

A method of video decoding at a video decoder, comprising:
receiving a first high level syntax (HLS) element indicating whether an explicit multiple transform selection (MTS) is enabled or disabled for an intra coded block;
receiving a second HLS element indicating whether the explicit MTS is enabled or disabled for an inter coded block, wherein the first and second HLS elements control a same set of coding blocks that include the intra coded block and the inter coded block; and
enabling an implicit MTS for the intra coded block when the first HLS element indicates the explicit MTS is disabled for the intra coded block, and the second HLS element indicates the explicit MTS is enabled for the inter coded block.

### Claim 2 (depends on 1)

The method of claim 1, further comprising:
applying the implicit MTS to the intra coded block, wherein a transform type for processing the intra coded block is determined according to a size of the intra coded block.

### Claim 3 (depends on 1)

The method of claim 1, wherein the first or second HLS element is one of:
a video parameter set (VPS) syntax element,
a sequence parameter set (SPS) syntax element,
a picture parameter set (PPS) syntax element,
a slice header syntax element,
a tile header syntax element, or
a tile group header syntax element.

### Claim 4 (depends on 1)

The method of claim 1, wherein the intra coded block is not coded with an intra sub-partitioning (ISP) mode.

### Claim 5 (depends on 1)

The method of claim 1, further comprising:
receiving a third HLS element indicating an MTS is enabled for each of the inter and intra coded blocks.

### Claim 6

A method of video decoding at a video decoder, comprising:
receiving a first high level syntax (HLS) element indicating whether an explicit multiple transform selection (MTS) is enabled or disabled for an intra coded block;
receiving a second HLS element indicating whether a Non-separable Separable Secondary Transform (NSST) or matrix-based intra prediction (MIP) is disabled or enabled for the intra coded block; and
enabling an implicit MTS for the intra coded block when the first HLS element indicates the explicit MTS is disabled for the intra coded block, and the second HLS element indicates the NSST or the MIP is disabled for the intra coded block.

### Claim 7 (depends on 6)

The method of claim 6, further comprising:
disabling the implicit MTS for the intra coded block when the first HLS element indicates the explicit MTS is disabled for the intra coded block, and the second HLS element indicates the NSST or the MIP is enabled for the intra coded block.

### Claim 8 (depends on 6)

The method of claim 6, wherein the enabling includes:
enabling the implicit MTS for the intra coded block when the first HLS element indicates the explicit MTS is disabled for the intra coded block, and both the NSST and the MIP are disabled for the intra coded block as indicated by HLS elements.

### Claim 9 (depends on 6)

The method of claim 6, further comprising:
applying the implicit MTS to the intra coded block.

### Claim 10 (depends on 6)

The method of claim 6, wherein the first or second HLS element is one of:
a video parameter set (VPS) syntax element,
a sequence parameter set (SPS) syntax element,
a picture parameter set (PPS) syntax element,
a slice header syntax element,
a tile header syntax element, or
a tile group header syntax element.

### Claim 11 (depends on 6)

The method of claim 6, wherein the intra coded block is not coded with an intra sub-partitioning (ISP) mode.

### Claim 12 (depends on 6)

The method of claim 6, further comprising:
receiving a third HLS element indicating an MTS is enabled for the intra coded block.

### Claim 13

A method of video decoding at a video decoder, comprising:
receiving an intra coded block associated with a first block level syntax element indicating whether a multiple transform selection (MTS) is applied, and a second block level syntax element indicating whether a non-separable secondary transform (NSST) is applied; and
enabling an implicit MTS for the intra coded block when the first block level syntax element indicates the MTS is not applied, and the second block level syntax element indicates the NSST is not applied.

### Claim 14 (depends on 13)

The method of claim 13, further comprising:
disabling the implicit MTS for the intra coded block when the first block level syntax element indicates the MTS is not applied, and the second block level syntax element indicates the NSST is applied.

### Claim 15 (depends on 13)

The method of claim 13, wherein the intra coded block is associated with a third block level syntax element indicating whether a matrix-based intra prediction (MIP) is applied, and
the enabling further includes enabling the implicit MTS for the intra coded block when the first block level syntax element indicates the MTS is not applied, the second block level syntax element indicates the NSST is not applied, and the third block level syntax element indicates the MIP is not applied.

### Claim 16 (depends on 15)

The method of claim 15, further comprising:
disabling the implicit MTS for the intra coded block when the first block level syntax element indicates the MTS is not applied, and either the second block level syntax element indicates the NSST is applied or the third block level syntax element indicates the MIP is applied.

### Claim 17 (depends on 13)

The method of claim 13, wherein the first block level syntax element indicates the MTS is not applied by indicating DCT-2 transforms are to be used for processing the intra coded block.

### Claim 18 (depends on 13)

The method of claim 13, further comprising:
applying the implicit MTS to the intra coded block.

### Claim 19 (depends on 13)

The method of claim 13, wherein the intra coded block is not coded with an intra sub-partitioning (ISP) mode.

### Claim 20 (depends on 13)

The method of claim 13, further comprising:
receiving a high level syntax (HLS) element indicating an MTS is enabled for the intra coded block.