# US 2020/0288174 A1 · Network abstraction layer unit header

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- Number: US 2020/0288174 A1
- Document ID: US20200288174A1
- Status: Published application
- Kind: A1
- Application number: 16/459,883
- Filed: 2019-07-02
- Published: 2020-09-10
- Earliest claimed: 2019-03-06
- Assignees: Tencent America LLC
- Applicants: Tencent America LLC
- Inventors: Stephan WENGER; Byeongdoo CHOI; Shan LIU
- Web page: https://patentgrep.com/patent/US20200288174A1

## CPC

- H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards
- H04N 19/188: {the unit being a video data packet, e.g. a network abstraction layer [NAL] unit}
- H04N 19/31: in the temporal domain
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

An approach for reconstructing a Network Abstraction Layer (NAL) unit for video decoding using at least one processor includes decoding a first syntax element included in a NAL unit header; determining, based on the first syntax element, a NAL unit class including a plurality of NAL unit types; decoding a second syntax element included in the NAL unit header; and based on the NAL unit class being a first NAL unit class, determining a NAL unit type from among the NAL unit types using a combination of the NAL unit class and the second syntax element. and reconstructing the NAL unit based on the determined NAL unit type; and based on the NAL unit class being a second NAL unit class, determining a temporal identifier (TID) based on the second syntax element, and reconstructing the NAL unit based on the determined TID.

## Claims

### Claim 1

A method of reconstructing a Network Abstraction Layer (NAL) unit for video decoding using at least one processor, the method comprising:
decoding a first syntax element comprising a first fixed length, binary-coded NAL unit syntax element included in a NAL unit header;
determining, based on the first syntax element, a NAL unit class comprising a plurality of NAL unit types;
decoding a second syntax element comprising a second fixed length, binary-coded NAL unit syntax element included in the NAL unit header, the second syntax element being different from the first syntax element.
based on the NAL unit class being a first NAL unit class, determining a NAL unit type from among the NAL unit types using a combination of the NAL unit class and the second syntax element, and reconstructing the NAL unit based on the determined NAL unit type, and
based on the NAL unit class being a second NAL unit class, determining a temporal identifier (TID) based on the second syntax element and reconstructing the NAL unit based on the determined TID.

### Claim 2 (depends on 1)

The method of claim 1, wherein based on the NAL unit class being the first NAL unit class, is determined to be zero.

### Claim 3 (depends on 1)

The method of claim 1, wherein the first NAL unit class indicates that a parameter set corresponding to the NAL unit relates to a plurality of temporal layers.

### Claim 4 (depends on 3)

The method of claim 3, wherein the parameter set comprises at least one from among a decoder parameter set, a video parameter set, and a sequence parameter set.

### Claim 5 (depends on 1)

The method of claim 1, wherein the first NAL unit class indicates that a parameter set corresponding to the NAL unit relates to a single coded picture.

### Claim 6 (depends on 5)

The method of claim 5, wherein the parameter set comprises at least one from among a picture parameter set, a slice parameter set, an adaptation parameter set, and a header parameter set.

### Claim 7 (depends on 1)

The method of claim 1, wherein the first NAL unit class indicates that the NAL unit relates to non-normative data.

### Claim 8 (depends on 7)

The method of claim 7, wherein the non-normative data comprises supplementary enhancement information, filler data, and picture delimiter data.

### Claim 9

(canceled)

### Claim 10 (depends on 1)

The method of claim 1, wherein the first syntax element comprises a forbidden zero bit.

### Claim 11

A device for reconstructing a Network Abstraction Layer (NAL) unit for video decoding, the device comprising:
at least one memory configured to store program code; and
at least one processor configured to read the program code and operate as instructed by the program code, the program code including:
first decoding code configured to cause the at least one processor to decode a first syntax element comprising a first fixed length, binary-coded NAL unit syntax element included in a NAL unit header;
first determining code configured to cause the at least one processor to, based on the first syntax element, determine a NAL unit class comprising a plurality of NAL unit types;
second decoding code configured to cause the at least one processor to decode a second syntax element comprising a second fixed length, binary-coded NAL unit syntax element included in the NAL unit header, the second syntax element being different from the first syntax element. second determining code configured to cause the at least one processor to, based on the NAL unit class being a first NAL unit class, determine a NAL unit type from among the NAL unit types using a combination of the NAL unit class and the second syntax element, and reconstruct the NAL unit based on the determined NAL unit type; and
third determining code configured to cause the at least one processor to, based on the NAL unit class being a second NAL unit class, determine a temporal identifier (TID) based on the second syntax element, and reconstruct the NAL unit based on the determined TID.

### Claim 12 (depends on 11)

The device of claim 11, wherein based on the NAL unit class being the first NAL unit class, the TID is determined to be zero.

### Claim 13 (depends on 11)

The device of claim 11, wherein the first NAL unit class indicates that a parameter set corresponding to the NAL unit relates to a plurality of temporal layers.

### Claim 14 (depends on 13)

The device of claim 13, wherein the parameter set comprises at least one from among a decoder parameter set, a video parameter set, and a sequence parameter set.

### Claim 15 (depends on 11)

The device of claim 11, wherein the first NAL unit class indicates that a parameter set corresponding to the NAL unit relates to a single coded picture.

### Claim 16 (depends on 15)

The device of claim 15, wherein the parameter set comprises at least one from among a picture parameter set, a slice parameter set, an adaptation parameter set, and a header parameter set.

### Claim 17 (depends on 11)

The device of claim 11, wherein the first NAL unit class indicates that the NAL unit relates to non-normative data.

### Claim 18

(canceled)

### Claim 19 (depends on 11)

The device of claim 11, wherein the first syntax element comprises a forbidden zero bit.

### Claim 20

A non-transitory computer-readable medium storing instructions, the instructions comprising: one or more instructions that, when executed by one or more processors of a device for reconstructing a Network Abstraction Layer (NAL) unit for video decoding, cause the one or more processors to:
decode a first syntax element included in a NAL unit header;
determine, based on the first syntax element, a NAL unit class comprising a plurality of NAL unit types;
decode a second syntax element included in the NAL unit header, the second syntax element being different from the first syntax element;
based on the NAL unit class being a first NAL unit class, determine a NAL unit type from among the NAL unit types using a combination of the NAL unit class and the second syntax element, and reconstruct the NAL unit based on the determined NAL unit type; and
wherein based on the NAL unit class being a second NAL unit class, determine a temporal identifier (TID) based on the second syntax element and reconstruct the NAL unit based on the determined TID.