Size based transform unit context derivation

Patent metadata

Field	Value
Publication number	US-11432011-B2
Application number	US-202017121669-A
Country	US
Kind code	B2
Filing date	Dec 14, 2020
Priority date	Aug 15, 2012
Publication date	Aug 30, 2022
Grant date	Aug 30, 2022

Abstract

Systems, apparatus, articles, and methods are described including operations for size based transform unit context derivation.

First claim

What is claimed:

1. An apparatus, comprising:
memory;
instructions; and
circuitry to execute the instructions to cause the circuitry to at least:
determine a transform unit (TU) size for a node of a TU quadtree, the TU associated with a coding unit (CU) and the TU associated with a video frame,
determine a context index value associated with an individual node of the TU quadtree based at least in part on the TU size, wherein to determine the context index value, the circuitry is to determine a difference between a binary logarithm of a maximum TU size and a binary logarithm of the transform unit size, and
determine a transform split flag based at least in part on the determined context index value.

2. The apparatus of claim 1 , wherein the circuitry is to determine the context index value as part of a context adaptive entropy coding operation to determine one or more transform split flags.

3. The apparatus of claim 1 , wherein the circuitry is to determine the context index value as part of an entropy Context-adaptive binary arithmetic coding (CABAC) coding of transform split flags to determine one or more transform split flags.

4. The apparatus of claim 1 , wherein the circuitry is to:
determine a first split flag having a first value when the transform unit has a size in excess of a first size, and wherein the first split flag is not explicitly provided in a bitstream; and
determine a second split flag of second value when the transform unit has a second size, and wherein the second split flag is not explicitly provided in a bitstream.

5. The apparatus of claim 1 , further comprising a video encoder, wherein the circuitry is part of the video encoder.

6. A system comprising:
a display;
an antenna configured to receive an encoded bitstream of video data;
a memory to store the bitstream;
a processor communicatively coupled to the display, antenna, and memory; and
decoder circuitry to:
determine a transform unit (TU) size for a node of a TU quadtree, the TU associated with a coding unit (CU) and the TU associated with a video frame,
determine a context index value associated with an individual node of the TU quadtree based at least in part on the TU size, wherein to determine the context index value, the circuitry is to determine a difference between a binary logarithm of a maximum TU size and a binary logarithm of the transform unit size, and
determine a transform split flag based at least in part on the determined context index value.

7. The system of claim 6 , wherein the decoder circuitry is to determine the context index value as part of a context adaptive entropy coding operation to determine one or more transform split flags.

8. The system of claim 6 , wherein the decoder circuitry is to determine the context index value as part of an entropy Context-adaptive binary arithmetic coding (CABAC) coding of transform split flags to determine one or more transform split flags.

9. The system of claim 6 , wherein the decoder circuitry is to:
determine a first split flag having a first value when the transform unit has a first size, and wherein the first split flag is not explicitly provided in the bitstream; and
determine a second split flag of second value when the transform unit has a second size, and wherein the second split flag is not explicitly provided in the bitstream.

10. The system of claim 9 , wherein the first size is 64×64 and the second size 4×4.

11. At least one non-transitory article comprising a computer program stored thereon having instructions that, if executed by the computer, cause the computer to:
determine a transform unit (TU) size for a node of a TU quadtree, the TU associated with a coding unit (CU) and the TU associated with a video frame,
determine a context index value associated with an individual node of the TU quadtree based at least in part on the TU size, wherein to determine the context index value;
determine a difference between a binary logarithm of a maximum TU size and a binary logarithm of the transform unit size, and
determine a transform split flag based at least in part on the determined context index value.

12. The non-transitory article of claim 11 , wherein the instructions, when executed, cause the computer to determine the context index value as part of a context adaptive entropy coding operation to determine one or more transform split flags.

13. The non-transitory article of claim 11 , wherein the instructions, when executed, cause the computer to determine the context index value as part of an entropy Context-adaptive binary arithmetic coding (CABAC) coding of transform split flags to determine one or more transform split flags.

14. The non-transitory article of claim 11 , wherein the instructions, when executed, cause the computer:
determine a first split flag having a first value when the transform unit has a first size, and wherein the first split flag is not explicitly provided in a bitstream; and
determine a second split flag of second value when the transform unit has a second size, and wherein the second split flag is not explicitly provided in the bitstream.

15. The non-transitory article of claim 14 , wherein the first size is 64×64 and the second size 4×4.

Assignees

• Intel Corp

Inventors

• Zhang Wenhao
• Chiu Yi-Jen
• Kapsenberg Pieter
• Xu Lidong
• Han Yu
• Deng Zhipin Apple
• Cai Xiaoxia

Classifications

• H04N19/60 Primary

  using transform coding · CPC title

• H04N19/13

  Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC] · CPC title

• H04N19/122 Primary

  Selection of transform size, e.g. 8x8 or 2x4x8 DCT; Selection of sub-band transforms of varying structure or type · CPC title

• H04N19/96

  Tree coding, e.g. quad-tree coding · CPC title

• H04N19/91

  Entropy coding, e.g. variable length coding [VLC] or arithmetic coding · CPC title