US 12,615,397 B2 · Independent history-based Rice parameter derivations for video coding

Abstract

In some embodiments, a video decoder decodes a video from a bitstream of the video using a history-based rice parameter derivation. The video decoder accesses a binary string representing a partition of the video and processes each coding tree unit (CTU) in the partition to generate decoded coefficient values in the CTU. The process includes updating a replacement variable for a transform unit (TU) in the CTU for calculating rice parameters independently of the previous TU or CTU. The process further includes calculating the rice parameters for TU in the CTU based on the value of the replacement variable and decoding the binary string corresponding to the TU into coefficient values based on the calculated rice parameters. Pixel values of the TU can be determined from the decoded coefficient values for output.

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Claims8

Dependent claims

A method for decoding a video, the method comprising:

accessing a binary string representing a partition of the video, the partition comprising a plurality of coding tree units (CTUs);
decoding each CTU of the plurality of CTUs in the partition, decoding the CTU comprising decoding a transform unit (TU) of the CTU by:
updating a replacement variable HistValue for calculating Rice parameters for the TU, wherein updating the replacement variable Hist Value is performed independently of another TU of the CTU that precedes the TU and another CTU of the plurality of CTUs that precedes the CTU;
calculating the Rice parameters for the TU in the CTU based on the updated replacement variable HistValue;
and
decoding the binary string corresponding to the TU in the CTU into coefficient values of the TU based on the calculated Rice parameters;
and
determining pixel values for the TU in the CTU from the coefficient values;
and
outputting a decoded partition of the video comprising the decoded plurality of CTUs in the partition,
wherein updating the replacement variable Hist Value comprises:
updating a history counter StatCoeff for a color component;
and
prior to calculating a next Rice parameter, updating the replacement variable Hist Value based on the updated history counter StatCoeff for the color component by:
HistValue[cIdx]=1<<StatCoeff[cIdx],
wherein updating the history counter StatCoeff comprises:
in response to determining that a first non-zero Golomb-Rice coded transform coefficient in a TU is coded as abs_remainder, updating a history counter StatCoeff for a color component cIdx as:
StatCoeff[cIdx]=(StatCoeff_init[cIdx]+Floor(Log 2(abs_remainder[cIdx]))+2)>>1;
and
in response to determining that the first non-zero Golomb-Rice coded transform coefficient in the TU is coded as dec_abs_level, updating the history counter StatCoeff for a color component cIdx as:
StatCoeff[cIdx]=(StatCoeff_init[cIdx]+Floor(Log 2(dec_abs_level[cIdx])))>>1,
wherein Floor(x) represents the largest integer less than or equal to x, and Log 2(x) is base-2 logarithm of x, wherein StatCoeff_init is an initial value of the history counter StatCoeff,
wherein the StatCoeff_init for a color component cIdx is determined for the partition based on at least one of:
statCoeff_init[idx]=2*Floor(Log 2(BitDepth−10)) or
statCoeff_init[idx]=Clip(MIN_Stat,MAX_Stat,(int)((19−QP)/6))−1,
wherein BitDepth specifies the bit depth of the samples of the luma or chroma arrays, and Floor(x) represents the largest integer less than or equal to x, and wherein MIN_Stat, MAX_Stat are two predefined integers, respectively, OP is the initial quantization parameter for each partition and Clip( ) is defined as follows:
Clip
(
x
,
y
,
z
)
=
{
x
;
z
<
x
y
;
z
>
y
z
;
otherwise
.

47 more elements

A system comprising:

a processing device;
and
a non-transitory computer-readable medium communicatively coupled to the processing device, wherein the processing device is configured to execute program code stored in the non-transitory computer-readable medium and thereby perform operations comprising:
accessing a binary string representing a partition of a video, the partition comprising a plurality of coding tree units (CTUs);
decoding each CTU of the plurality of CTUs in the partition, decoding the CTU comprising decoding a transform unit (TU) of the CTU by:
updating a replacement variable HistValue for calculating Rice parameters for the TU, wherein updating the replacement variable Hist Value is performed independently of another TU of the CTU that precedes the TU and another CTU of the plurality of CTUs that precedes the CTU;
calculating the Rice parameters for the TU in the CTU based on the updated replacement variable Hist Value;
and
decoding the binary string corresponding to the TU in the CTU into coefficient values of the TU based on the calculated Rice parameters;
and
determining pixel values for the TU in the CTU from the coefficient values;
and
outputting a decoded partition of the video comprising the decoded plurality of CTUs in the partition,
wherein updating the replacement variable Hist Value comprises:
updating a history counter StatCoeff for a color component;
and
prior to calculating a next Rice parameter, updating the replacement variable Hist Value based on the updated history counter StatCoeff for the color component by:
HistValue[cIdx]=1<<StatCoeff[cIdx],
wherein updating the history counter StatCoeff comprises:
in response to determining that a first non-zero Golomb-Rice coded transform coefficient in a TU is coded as abs_remainder, updating a history counter StatCoeff for a color component cIdx as:
StatCoeff[cIdx]=(StatCoeff_init[cIdx]+Floor(Log 2(abs_remainder[cIdx]))+2)>>1;
and
in response to determining that the first non-zero Golomb-Rice coded transform coefficient in the TU is coded as dec_abs_level, updating the history counter StatCoeff for a color component cIdx as:
StatCoeff[cIdx]=(StatCoeff_init[cIdx]+Floor(Log 2(dec_abs_level[cIdx])))>>1,
wherein Floor(x) represents the largest integer less than or equal to x, and Log 2(x) is base-2 logarithm of x, wherein StatCoeff_init is an initial value of the history counter StatCoeff,
wherein the StatCoeff_init for a color component cIdx is determined for the partition based on at least one of:
statCoeff_init[idx]=2*Floor(Log 2(BitDepth−10)) or
statCoeff_init[idx]=Clip(MIN_Stat,MAX_Stat,(int)((19−QP)/6))−1,
wherein BitDepth specifies the bit depth of the samples of the luma or chroma arrays, and Floor(x) represents the largest integer less than or equal to x, and wherein MIN_Stat, MAX_Stat are two predefined integers, respectively, QP is the initial quantization parameter for each partition and Clip( ) is defined as follows:
Clip
(
x
,
y
,
z
)
=
{
x
;
z
<
x
y
;
z
>
y
z
;
otherwise
.

50 more elements

A method for encoding a video, the method comprising:

accessing a partition of the video, the partition comprising a plurality of coding tree units (CTUs);
processing the partition of the video to generate a binary representation of the partition, the processing comprising:
encoding each CTU of the plurality of CTUs in the partition, encoding the CTU comprising encoding a transform unit (TU) of the CTU by:
updating a replacement variable HistValue for calculating Rice parameters for the TU, wherein updating the replacement variable Hist Value is performed independently of (a) another TU of the CTU that precedes the TU and (b) another CTU of the plurality of CTUs that precedes the CTU;
calculating the Rice parameters for the TU in the CTU based on the updated replacement variable Hist Value;
and
encoding coefficient values of the TU into a binary representation corresponding to the TU in the CTU based on the calculated Rice parameters;
and
encoding the binary representation of the partition into a bitstream of the video,
wherein updating the replacement variable Hist Value comprises:
updating a history counter StatCoeff for a color component;
and
prior to calculating a next Rice parameter, updating the replacement variable Hist Value based on the updated history counter StatCoeff for the color component by:
HistValue[cIdx]=1<<StatCoeff[cIdx],
wherein updating the history counter StatCoeff comprises:
in response to determining that a first non-zero Golomb-Rice coded transform coefficient in a TU is coded as abs_remainder, updating a history counter StatCoeff for a color component cIdx as:
StatCoeff[cIdx]=(StatCoeff_init[cIdx]+Floor(Log 2(abs_remainder[cIdx]))+2)>>1;
and
in response to determining that the first non-zero Golomb-Rice coded transform coefficient in the TU is coded as dec_abs_level, updating the history counter StatCoeff for a color component cIdx as:
StatCoeff[cIdx]=(StatCoeff_init[cIdx]+Floor(Log 2(dec_abs_level[cIdx])))>>1,
wherein Floor(x) represents the largest integer less than or equal to x, and Log 2(x) is base-2 logarithm of x, wherein StatCoeff_init is an initial value of the history counter StatCoeff,
wherein the StatCoeff_init for a color component cIdx is determined for the partition based on at least one of:
statCoeff_init[idx]=2*Floor(Log 2(BitDepth−10)) or
statCoeff_init[idx]=Clip(MIN_Stat,MAX_Stat,(int)((19−QP)/6))−1,
wherein BitDepth specifies the bit depth of the samples of the luma or chroma arrays, and Floor(x) represents the largest integer less than or equal to x, and wherein MIN_Stat, MAX_Stat are two predefined integers, respectively, QP is the initial quantization parameter for each partition and Clip( ) is defined as follows:
Clip
(
x
,
y
,
z
)
=
{
x
;
z
<
x
y
;
z
>
y
z
;
otherwise
.

46 more elements

Dependencies are inferred from the claim text.

Description13,013 words

Summary1,303 words

#This disclosure relates generally to computer-implemented methods and systems for video processing. Specifically, the present disclosure involves independent history based Rice parameter derivations for video coding.

#The ubiquitous camera-enabled devices, such as smartphones, tablets, and computers, have made it easier than ever to capture videos or images. However, the amount of data for even a short video can be substantially large. Video coding technology (including video encoding and decoding) allows video data to be compressed into smaller sizes thereby allowing various videos to be stored and transmitted. Video coding has been used in a wide range of applications, such as digital TV broadcast, video transmission over the internet and mobile networks, real-time applications (e.g., video chat, video conferencing), DVD and Blu-ray discs, and so on. To reduce the storage space for storing a video and/or the network bandwidth consumption for transmitting a video, it is desired to improve the efficiency of the video coding scheme.

#Some embodiments involve independent history-based Rice parameter derivations for video coding. In one example, a method for decoding a video includes accessing a binary string representing a partition of the video, the partition comprising a plurality of coding tree units (CTUs); decoding each CTU of the plurality of CTUs in the partition, decoding the CTU comprising decoding a transform unit (TU) of the CTU by: updating a replacement variable HistValue for calculating Rice parameters for the TU, wherein updating the replacement variable HistValue is performed independently of another TU of the CTU that precedes the TU and another CTU of the plurality of CTUs that precedes the CTU; calculating the Rice parameters for the TU in the CTU based on the updated replacement variable HistValue; and decoding the binary string corresponding to the TU in the CTU into coefficient values of the TU based on the calculated Rice parameters; and determining pixel values for the TU in the CTU from the coefficient values; and outputting a decoded partition of the video comprising the decoded plurality of CTUs in the partition.

Brief description of the drawings9 figures

#Features, embodiments, and advantages of the present disclosure are better understood when the following Detailed Description is read with reference to the accompanying drawings.

#FIG. 1 is a block diagram showing an example of a video encoder configured to implement embodiments presented herein.

#FIG. 2 is a block diagram showing an example of a video decoder configured to implement embodiments presented herein.

Detailed description11,488 words

#Various embodiments provide independent history-based Rice parameter derivations for video coding. As discussed above, more and more video data are being generated, stored, and transmitted. It is beneficial to increase the efficiency of the video coding technology thereby using less data to represent a video without compromising the visual quality of the decoded video. One way to improve coding efficiency is through entropy coding to compress processed video samples into a binary bitstream using as few bits as possible.

#In entropy coding, transform coefficient data are binarized to binary bins and coding algorithms such as context-adaptive binary arithmetic coding (CABAC) can further compress bins into bits. The binarization requires the calculation of a binarization parameter, such as the Rice parameter used in a combination of truncated Rice (TR) and limited k-th order Exp-Golomb (EGk) binarization process as specified in the Versatile Video Coding (VVC) specification. To improve the coding efficiency, a method of history-based Rice parameter derivation is used. In this method, the Rice parameter for a transform unit (TU) in a current coding tree unit (CTU) of a partition (e.g., a picture, a slice, or a tile) is derived based on a history counter (denoted as StatCoeff) calculated according to coefficients in previous TUs in the current CTU and previous CTU(s) in the partition. The history counter is then used to derive a replacement variable (denoted as HistValue) to be used to derive the Rice parameter. The history counter may be updated when processing a TU and the update is made based on the previous StatCoeff which is derived from the previous TU in the current CTU or the previous CTU. As a result, the history value used in the derivation of Rice parameters of all scan positions in the current TU is based upon the information of the previous TU. This creates the dependency between the current TU and the previous TU in the current CTU or even the previous CTU in some cases. Such a design is not hardware friendly and may prevent parallel processing of multiple CTUs or TUs.

#Various embodiments described herein address these problems by providing independent history-based Rice parameter derivation so that the Rice parameter derivation for each TU is independent of the Rice parameter derivation for other TUs. The following non-limiting examples are provided to introduce some embodiments.

Facts

Application

18/685,141Filed 25 Aug 2022 · us provisional application

Priority

26 Aug 2021

Published

US 2024/0364939 A131 Oct 2024

Granted

28 Apr 2026

Term ends

6 Sep 2042

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 12 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification10 codes

H04N 19/13
Characterised by the element, parameter or selection affected or controlled by the adaptive coding: adaptive entropy coding, e.g. adaptive…
H04N 19/96
Using coding techniques not provided for in groups H04N19/10-H04N19/85, e.g. fractals: tree coding, e.g. quad-tree coding
H04N 19/124
Characterised by the element, parameter or selection affected or controlled by the adaptive coding: quantisation
H04N 19/176
The unit being an image region, e.g. an object: the region being a block, e.g. a macroblock

Family

Application63/260,604Us provisional application · filed 26 Aug 2021

Application63/248,289Us provisional application · filed 24 Sep 2021

Application63/248,819Us provisional application · filed 27 Sep 2021

Application63/250,964Us provisional application · filed 30 Sep 2021

US 2024/0364939 A1Pre-grant publication · published 31 Oct 2024

US 12,615,397 B2This patent

From the US filing history. Foreign family members aren’t listed.

Timeline

26 Aug 2021Priority claimedParent application 63/260,604
25 Aug 2022Application filedUS 18/685,141
20 Feb 2024Assigned to Innopeak Technology, Inc.assignment of assignor's interest
1 Apr 2024Assigned to Guangdong Oppo Mobile Telecommunications Corp., Ltd.assignment of assignor's interest
31 Oct 2024PublishedUS 2024/0364939 A1
28 Apr 2026GrantedUS 12,615,397 B2
12 Oct 2026TodayWithin its term
6 Sep 2042Term endsEstimated, includes 12 days of adjustment

Independent history-based Rice parameter derivations for video coding

Life of this patent

Independent history-based Rice parameter derivations for video coding

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims8

Description13,013 words

Drawings

Classification10 codes

Life of this patent

Description13,013 words