CN111416981A

CN111416981A - Video image decoding and encoding method and device

Info

Publication number: CN111416981A
Application number: CN201910017708.0A
Authority: CN
Inventors: 王业奎; 虞露; 范宇群; 于化龙; 袁锜超; 赵寅; 杨海涛
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd; Zhejiang University ZJU
Priority date: 2019-01-07
Filing date: 2019-01-07
Publication date: 2020-07-14
Anticipated expiration: 2039-01-07
Also published as: WO2020143589A1; CN111416981B

Abstract

The application provides a video image decoding and encoding method and a device, when determining to perform interframe prediction on a current image to be processed to refer to a knowledge base image, a first identifier is coded in a code stream, the first identifier is used for indicating whether a reconstructed pixel value of the current image to be processed copies a pixel value of the referenced knowledge base image, under the condition that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image, the current image to be processed does not need to be subjected to video coding and decoding (such as motion compensation) by using the knowledge base image, so that the coding and decoding redundancy of the main code stream and the knowledge base code stream can be avoided to a certain extent (for example, the necessity of further decoding the video image in the main code stream after decoding the reference image in the knowledge layer code stream) aiming at the condition that the video image in the main code stream and the reference image in the knowledge base code stream have the same or nearly same (such as similar) pixel value, thereby improving the encoding and decoding performance.

Description

Video image decoding and encoding method and device

Technical Field

The present application relates to the field of image encoding and decoding technologies, and in particular, to a method and an apparatus for decoding and encoding a video image.

Background

In order to provide random access capability, images capable of supporting random access are periodically inserted into a video, and the video is divided into a plurality of independent random access segments which cannot be mutually referenced. In order to mine and utilize information of mutual reference of images among a plurality of random access segments during encoding, a knowledge base encoding scheme introduces a knowledge base image (which may be simply referred to as a knowledge image), wherein the knowledge base image is an image out of an image set required to be displayed in a random access segment to which a current image belongs and a random access segment which is closest to the current image in the random access segments, and the knowledge base image serves as a reference image (such as a long-term reference image) to provide reference for an image to be encoded or an image to be decoded.

The video sequence is encoded by adopting video coding based on a knowledge base, a knowledge layer code stream containing a knowledge base image coding code stream and a main code stream containing a code stream obtained by referring the knowledge base image coding to the video sequence image are generated, and the knowledge base image can be repeatedly referred by random access segments of a plurality of main code streams.

The decoding of the main video code stream must rely on the knowledge base code stream, and when the video image of the main video code stream is decoded, if the image refers to a certain image in the knowledge base code stream, the video image in the main video code stream can be decoded only after the image in the knowledge base code stream is decoded, so that the performance of encoding and decoding is low.

Disclosure of Invention

The application provides a video image decoding and encoding method and device, aiming at a scene that decoding of a video main code stream depends on a code stream of a knowledge base, and improving the encoding and decoding performance of a video image.

In a first aspect, an embodiment of the present application provides a video image decoding method, including:

when the current image to be processed is determined to be subjected to inter-frame prediction and reference to the knowledge base image, analyzing a first identifier from a code stream; when the first identifier indicates that the reconstructed pixel value of the current to-be-processed image copies the pixel value of the knowledge base image (e.g., the reconstructed pixel value of the knowledge base image or the original pixel value of the knowledge base image), acquiring (e.g., from a knowledge base image storage unit) the pixel value of the knowledge base image referred to by the current to-be-processed image; and determining a reconstruction pixel value of the current image to be processed according to the acquired pixel value of the knowledge base image.

Illustratively, the first identifier is used to indicate whether reconstructed pixel values of the current image to be processed copy pixel values of the knowledge base image. For example, when the first identifier value is bore/1, indicating the reconstructed pixel value of the current image to be processed to copy the pixel value of the knowledge base image; and otherwise, when the first identification value is false/0, indicating that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image.

The first flag may be represented by copy _ rec _ library _ picture _ flag in standard text or code. For example, when copy _ rec _ texture _ picture _ flag is equal to 1, it indicates that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image, and when copy _ rec _ texture _ picture _ flag is equal to 0, it indicates that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image.

It should be understood that the copy operations referred to in the embodiments of the present application include, but are not limited to, conventional direct copying. The following examples illustrate several copies referred to in the examples of this application:

example 1, copying such that the reconstructed pixel values of the current to-be-processed image are identical to the pixel values of the reference knowledge image;

example 2, copying is performed such that the predicted pixel value of the current image to be processed is identical to the pixel value of the knowledge image to which the current image to be processed refers, and the reconstructed pixel value of the current image to be processed is obtained by combining (e.g., summing or superimposing) the predicted pixel value of the current image to be processed and the predicted residual of the current image to be processed.

Example 3, copying is performed such that the predicted pixel value of the current image to be processed is identical to the reconstructed pixel value of the knowledge image to which the current image to be processed refers, and the reconstructed pixel value of the current image to be processed is obtained by combining (e.g., summing or superimposing) the predicted pixel value of the current image to be processed and post-processing information (e.g., filtered information, etc.) of the current image to be processed.

According to the scheme, the first identifier is added in the code stream, when the first identifier indicates that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image, the process of decoding the reconstructed pixel value of the current image to be processed in the main code stream is simplified to a certain extent, that is, the pixel value of the current image to be processed is determined by copying the pixel value of the knowledge base image (for example, the pixel value of the knowledge base image is taken as the pixel value of the current image to be processed), so that the encoding and decoding redundancy of the main code stream and the knowledge base code stream is avoided to a certain extent aiming at the situation that a video image in the main code stream and a reference image in the knowledge base code stream have the same or nearly the same (for example, similar) pixel value, and the encoding and decoding performance is improved.

In one possible design, further comprising:

when the first identification indicates that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image, a second identification is analyzed from the code stream, and the second identification is used for indicating the knowledge base image referred by the current image to be processed; the acquiring the pixel value of the knowledge base image referred by the current image to be processed comprises: and acquiring the pixel value of the knowledge base image indicated by the second identification. For example, the design may be applied in a scene complying with an audio video coding standard (AVS).

Illustratively, the second identifier is an index of a knowledge base image referred to by the current image to be processed, and the second identifier may be represented by a syntax element coded _ library _ picture _ idx _ in _ rcs in standard text or code.

In addition, it should be understood that there may be only one knowledge base image that can be referred to by the current image to be processed, in other words, only one available knowledge base image may exist in the external knowledge base at any time, and the second identifier does not need to be encoded during encoding, and certainly does not need to be decoded during decoding, and the pixel value of the knowledge base image that can be referred to by the current image to be processed may be directly copied to determine the reconstructed pixel value of the current image to be processed.

In one possible design, further comprising: when the current image to be processed is determined to be inter-frame predicted and referred to a knowledge base image, analyzing a third identifier from the code stream, wherein the third identifier is used for indicating the knowledge base image referred to by the current image to be processed; acquiring a pixel value of a knowledge base image referred by the current image to be processed, wherein the pixel value comprises the following steps: and acquiring the pixel value of the knowledge base image indicated by the third identification. For example, the design may be applied to scenes that comply with High Efficiency Video Coding (HEVC) or multi-function video coding (VVC).

Illustratively, the third identifier is an index of the knowledge base image, and in standard text or code, the third identifier may be represented by a library _ picture _ id.

In one possible design, whether inter-prediction of the current image to be processed refers to a knowledge base image is determined by either:

a first possible way: a fourth flag (for example, the fourth flag may be represented by reference _ to _ library _ picture _ flag) is parsed from the bitstream, the fourth flag is a syntax element of a picture level, and the fourth flag indicates whether inter prediction is performed on a current picture to be processed with reference to a knowledge base picture. Illustratively, the fourth flag is a first value (e.g., tune or 1) to indicate that the current image to be processed is inter-predicted with reference to a knowledge base image; otherwise, the fourth flag is a second value (e.g., false or 0) to indicate that inter-prediction on the current image to be processed does not refer to the knowledge base image.

A second possible way: analyzing a fifth identifier (for example, the fifth identifier may be represented by a library _ picture _ enable _ flag) from the code stream, where the fifth identifier is a syntax element of a sequence level, the fifth identifier indicates whether inter-frame prediction is performed on a video sequence where a current image to be processed refers to a knowledge base image, and when the fifth identifier indicates that inter-frame prediction is performed on a video sequence where a current image to be processed refers to a knowledge base image, determining whether inter-frame prediction is performed on a current image to be processed refers to a knowledge base image based on a reference image configuration set analyzed from the code stream;

illustratively, the fifth flag is a first value (e.g., tune or 1) to indicate that inter-prediction is performed on a reference knowledge base image of a video sequence in which a current image to be processed is located; otherwise, the fifth flag is a second value (e.g., false or 0) to indicate that inter-prediction is performed on the video sequence in which the current image to be processed is located without referring to the knowledge base image.

A third possible way: analyzing a reference image configuration set from the code stream, and determining whether inter-frame prediction is performed on a current image to be processed to refer to a knowledge base image or not based on the reference image configuration set;

a fourth possible way: and parsing a sixth flag from the code stream (for example, the sixth flag may be represented by a library _ picture _ enable _ flag), and when the sixth flag indicates that inter-prediction is performed on a video sequence in which a current picture to be processed is located and reference to a knowledge base picture, parsing a seventh flag from the code stream (for example, the seventh flag may be represented by a reference _ to _ library _ picture _ flag), the seventh flag indicating whether inter-prediction is performed on the current picture to be processed and reference to the knowledge base picture.

Illustratively, the sixth flag is a syntax element of a sequence level, the sixth flag is used for indicating whether inter-prediction is performed on a video sequence in which a current image to be processed refers to a knowledge base image, and the sixth flag is a first value (e.g. tube or 1) to indicate that inter-prediction is performed on the video sequence in which the current image to be processed refers to the knowledge base image; otherwise, the sixth flag is a second value (e.g., false or 0) to indicate that inter-prediction is performed on the video sequence in which the current image to be processed is located without referring to the knowledge base image. Illustratively, the seventh flag is a first value (e.g., tune or 1) to indicate that the current image to be processed is inter-predicted with reference to a knowledge base image; otherwise, the seventh flag is a second value (e.g., false or 0) to indicate that inter-prediction on the current image to be processed does not refer to the knowledge base image.

The design provides several modes for determining whether the current image to be processed is subjected to inter-frame prediction to refer to the knowledge base image, and is simple and easy to implement.

In one possible design, further comprising: when the first identification indicates that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image, the reconstructed pixel value of the current image to be processed is obtained in a non-copy mode by using the knowledge base image referred by the current image to be processed. Or when the first decoded identifier does not exist in the code stream, determining that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image, and obtaining the reconstructed pixel value of the current image to be processed in a non-copy manner by using the knowledge base image referred by the current image to be processed.

When the reconstructed pixel value of the current image to be processed is obtained in a non-copy manner, for example, the obtained pixel value of the image in the knowledge base may be used as the pixel value of the current image to be processed, or the pixel value of the image in the knowledge base and the prediction residual error of the current image to be processed may be jointly determined (for example, superimposed) to obtain the reconstructed pixel value of the current image to be processed, and for example, the pixel value of the image in the knowledge base may be used as the predicted pixel value of the current image to be processed, and then the predicted pixel value of the current image to be processed and post-processing information (for example, filtered information and the like) of the current image to be processed are jointly obtained.

In one possible design, the first identifier is carried in a slice header (e.g., slice _ segment _ header), a picture header (e.g., inter _ picture _ header), or a sequence header.

In one possible design, the determining a reconstructed pixel value of the current image to be processed based on the pixel values of the acquired knowledge base image includes: and taking the pixel value of the acquired knowledge base image as a reconstruction pixel value of the current image to be processed.

In a second aspect, an embodiment of the present application provides a video image encoding method, including:

coding the coding information into a code stream;

when the current image to be processed is determined to be inter-frame predicted to refer to a knowledge base image, the coding information comprises a first identifier, and the first identifier is used for indicating whether a reconstructed pixel value of the current image to be processed copies a pixel value of the knowledge base image;

when the first identifier is a first numerical value, the first identifier is used for indicating the pixel value of the reconstructed pixel value copy knowledge base image of the current image to be processed.

For example, the first identifier is a first numerical value when the pixel value of the current to-be-processed image is the same as the pixel value of the reference knowledge base image, or when the pixel value of the current to-be-processed image is substantially close to the same as the pixel value of the reference knowledge base image (for example, the similarity between the current to-be-processed image and the reference knowledge base image reaches a preset threshold).

According to the scheme, the first identifier is added in the code stream, when the first identifier indicates that the pixel value of the current image to be processed is copied to the pixel value of the knowledge base image, the pixel value of the current image to be processed in the main code stream is not required to be decoded any more, but the pixel value of the current image to be processed is determined by copying the pixel value of the knowledge base image, so that the coding and decoding redundancy of the main code stream and the knowledge base code stream can be avoided to a certain extent, the use of coding and decoding resources is reduced, and the bit cost of the code stream is reduced.

In a possible design, when the first identifier is a first numerical value, a second identifier is further included in the encoded information, and the second identifier is used for indicating a knowledge base image referred to by the current image to be processed; wherein the pixel value of the knowledge base image indicated by the second identifier is used for determining a reconstructed pixel value of the current image to be processed.

In one possible design, the second identifier is located after the first identifier in the code stream.

In one possible design, when it is determined that the current image to be processed refers to a knowledge base image for inter-prediction, the encoding information further includes a third identifier, where the third identifier is used to indicate the knowledge base image referred to by the current image to be processed; wherein the pixel value of the knowledge base image indicated by the third identifier is used for determining a reconstructed pixel value of the current image to be processed.

In one possible design, when the first flag is a second value, the first flag is used to indicate that the reconstructed pixel values of the current to-be-processed image do not copy the pixel values of the knowledge base image. Correspondingly, other marks used for indicating that the reconstructed pixel value of the current image to be processed is determined by a non-copy method can be further included in the coded information;

for example, the other identifier may include an identifier indicating an inter prediction mode, such as whether a merge model is used, an identifier indicating a reference frame of a current image to be processed, or an index of a motion vector.

In one possible design, when it is determined that inter-frame prediction is performed on a current image to be processed to refer to a knowledge base image, the code stream does not include a first identifier to indicate that a reconstructed pixel value of the current image to be processed does not copy a pixel value of the knowledge base image.

In one possible design, the encoding information further includes a fourth flag, where the fourth flag is a syntax element of a picture level, and the fourth flag is used to indicate whether inter-prediction on a current picture to be processed refers to a knowledge base picture. And in the code stream, the first identifier is positioned after the fourth identifier.

Illustratively, the fourth flag is a first value (e.g., tune or 1) to indicate that the current image to be processed is inter-predicted with reference to a knowledge base image; otherwise, the fourth flag is a second value (e.g., false or 0) to indicate that inter-prediction on the current image to be processed does not refer to the knowledge base image.

In a possible design, the encoding information further includes a fifth flag (such as a library _ picture _ enable _ flag) and a reference picture configuration set, where the fifth flag is a syntax element of a sequence level, the fifth flag indicates whether inter-frame prediction is performed on a video sequence in which a current picture to be processed refers to a knowledge base picture, and when the fifth flag indicates that inter-frame prediction is performed on a video sequence in which a current picture to be processed refers to a knowledge base picture, the reference picture configuration set is used to indicate whether inter-frame prediction is performed on the current picture to be processed refers to a knowledge base picture. For example, in the code stream, the first identifier is located after the reference image configuration set, and the reference image configuration set is located after the fifth identifier.

In a possible design, the encoding information further includes a reference picture configuration set, where the reference picture configuration set is used to indicate whether inter-prediction is performed on a current picture to be processed with reference to a knowledge base picture. For example, in the code stream, the first identifier is located after the reference image configuration set.

In a possible design, the encoding information further includes a sixth flag (e.g., library _ picture _ enable _ flag), where the sixth flag is a syntax element of a sequence level, the sixth flag indicates whether inter-prediction is performed on a video sequence in which the current picture to be processed refers to a knowledge base picture, and when the sixth flag indicates that inter-prediction is performed on the video sequence in which the current picture to be processed refers to the knowledge base picture, the encoding information further includes a seventh flag (e.g., reference _ to _ library _ picture _ flag), and the seventh flag is used to indicate whether inter-prediction is performed on the current picture to be processed refers to the knowledge base picture.

In one possible design, the first identifier is carried in a slice header, a picture header (e.g., inter picture header), or a sequence header.

In a third aspect, an embodiment of the present application provides a video image decoding apparatus, which includes several functional units for implementing any one of the methods of the second aspect.

For example, a video image decoding apparatus may include an image storage unit and a decapsulation unit.

The image storage unit is used for storing knowledge base images;

the decapsulation unit is used for analyzing the first identifier from the code stream when determining that the current image to be processed is subjected to inter-frame prediction with reference to the knowledge base image; when the first identification indicates that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image, acquiring the pixel value of the knowledge base image referred by the current image to be processed from the image storage unit; and determining a reconstruction pixel value of the current image to be processed according to the acquired pixel value of the knowledge base image.

In a possible design, the decapsulating unit is further configured to, when the first identifier indicates that a reconstructed pixel value of the current image to be processed copies a pixel value of the knowledge base image, parse a second identifier from the code stream, where the second identifier is used to indicate a knowledge base image referred to by the current image to be processed; the decapsulation unit is specifically configured to, in terms of obtaining the pixel value of the knowledge base image referred to by the current image to be processed, obtain the pixel value of the knowledge base image indicated by the second identifier from the image storage unit.

In a possible design, the decapsulating unit is further configured to, when it is determined that inter-frame prediction is performed on a current image to be processed to refer to a knowledge base image, parse a third identifier from the code stream, where the third identifier is used to indicate the knowledge base image referred to by the current image to be processed;

the decapsulation unit is specifically configured to, in terms of obtaining the pixel value of the knowledge base image referred to by the current image to be processed, obtain the pixel value of the knowledge base image indicated by the third identifier from the image storage unit.

In one possible design, the decapsulating unit is further configured to determine whether inter-prediction performed on the current image to be processed refers to a knowledge base image by any one of:

analyzing a fourth identifier from the code stream, wherein the fourth identifier is a syntax element of an image level, and the fourth identifier indicates whether inter-frame prediction is performed on a current image to be processed to refer to a knowledge base image;

alternatively, the first and second electrodes may be,

analyzing a fifth identification from the code stream, wherein the fifth identification is a sequence level syntax element, the fifth identification indicates whether inter-frame prediction is performed on a video sequence in which a current image to be processed refers to a knowledge base image, and when the fifth identification indicates that inter-frame prediction is performed on the video sequence in which the current image to be processed refers to the knowledge base image, determining whether inter-frame prediction is performed on the current image to be processed refers to the knowledge base image based on a reference image configuration set analyzed from the code stream;

alternatively, the first and second electrodes may be,

analyzing a reference image configuration set from the code stream, and determining whether inter-frame prediction is performed on a current image to be processed to refer to a knowledge base image or not based on the reference image configuration set;

alternatively, the first and second electrodes may be,

and resolving a sixth identifier from the code stream, and resolving a seventh identifier from the code stream when the sixth identifier indicates that the current to-be-processed image is subjected to inter-frame prediction on a video sequence in which the current to-be-processed image is positioned and refers to a knowledge base image, wherein the seventh identifier indicates whether the current to-be-processed image is subjected to inter-frame prediction or not to refer to the knowledge base image.

In one possible design, the apparatus further includes a decoding unit, and the decapsulating unit is further configured to obtain, by the decoding unit, a reconstructed pixel value of the current image to be processed in a non-copy manner using the knowledge base image when the first identifier indicates that the reconstructed pixel value of the current image to be processed does not copy a pixel value of the knowledge base image.

In one possible design, the first identifier is carried in a slice header, a picture header, or a sequence header.

In one possible design, in determining the reconstructed pixel value of the current image to be processed based on the acquired pixel value of the knowledge base image, the decapsulating unit is specifically configured to use the acquired pixel value of the knowledge base image as the reconstructed pixel value of the current image to be processed.

In a fourth aspect, an embodiment of the present application provides a video image encoding apparatus, which includes several functional units for implementing any one of the methods in the third aspect.

For example, a video image encoding apparatus may include:

an image storage unit for storing a knowledge base image;

the code stream packaging unit is used for coding the coding information into the code stream;

when it is determined that the current image to be processed is subjected to inter-frame prediction and refers to the knowledge base image, the coding information includes a first identifier, the first identifier is used for indicating whether a reconstructed pixel value of the current image to be processed copies a pixel value of the knowledge base image, and when the first identifier is a first numerical value, the first identifier is used for indicating that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image.

In one possible design, when the first flag is a second numerical value, the first flag is used to indicate that the reconstructed pixel values of the current to-be-processed image do not copy the pixel values of the knowledge base image; correspondingly, other marks used for indicating that the reconstructed pixel value of the current image to be processed is determined by a non-copy method are also included in the coded information.

In one possible design, the encoding information further includes a fourth flag, where the fourth flag is a syntax element of a picture level, and the fourth flag is used to indicate whether inter-prediction on a current picture to be processed refers to a knowledge base picture.

In a possible design, the encoding information further includes a fifth identifier and a reference image configuration set, where the fifth identifier is a sequence-level syntax element, the fifth identifier indicates whether inter-frame prediction is performed on a video sequence in which a current image to be processed refers to a knowledge base image, and when the fifth identifier indicates that inter-frame prediction is performed on the video sequence in which the current image to be processed refers to the knowledge base image, the reference image configuration set is used to indicate whether inter-frame prediction is performed on the current image to be processed refers to the knowledge base image.

In a possible design, the encoding information further includes a reference picture configuration set, where the reference picture configuration set is used to indicate whether inter-prediction is performed on a current picture to be processed with reference to a knowledge base picture.

In a possible design, the coding information further includes a sixth flag, where the sixth flag is a syntax element of a sequence level, the sixth flag indicates whether inter-prediction is performed on a video sequence in which a current image to be processed is referred to a knowledge base image, and when the sixth flag indicates that inter-prediction is performed on the video sequence in which the current image to be processed is referred to the knowledge base image, the coding information further includes a seventh flag, where the seventh flag is a syntax element of an image level, and the seventh flag is used to indicate whether inter-prediction is performed on the current image to be processed is referred to the knowledge base image.

In a fifth aspect, an embodiment of the present application provides a video decoder, where the video decoder is configured to decode an image from a code stream.

Illustratively, a video decoder may implement any of the methods described in the first aspect. A video decoder comprises the apparatus of any design of the third aspect.

In a sixth aspect, embodiments of the present application provide a video encoder for encoding an image.

Illustratively, the video encoder may implement the method of the second aspect. A video encoder includes the apparatus as designed in any of the fourth aspects.

In a seventh aspect, an embodiment of the present application provides an apparatus for decoding video data, where the apparatus includes:

the memory is used for storing video data in a code stream form;

the video decoder is used for analyzing the first identifier from the code stream when determining that the current image to be processed is subjected to inter-frame prediction and refers to the knowledge base image; when the first identification indicates that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image, acquiring the pixel value of the knowledge base image referred by the current image to be processed; and determining a reconstruction pixel value of the current image to be processed according to the acquired pixel value of the knowledge base image.

In one possible design, when the first identifier indicates that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image, the video decoder parses a second identifier from the code stream, where the second identifier is used to indicate the knowledge base image referred to by the current image to be processed; in the aspect of obtaining the pixel value of the knowledge base image referred to by the current image to be processed, the method is specifically configured to: and acquiring the pixel value of the knowledge base image indicated by the second identification.

In one possible design, the video decoder is further configured to, when it is determined that inter-frame prediction is performed on a current image to be processed to refer to a knowledge base image, parse a third identifier from the code stream, where the third identifier is used to indicate the knowledge base image referred to by the current image to be processed; in the aspect of obtaining the pixel value of the knowledge base image referred to by the current image to be processed, the method is specifically configured to: and acquiring the pixel value of the knowledge base image indicated by the third identification.

In an eighth aspect, an embodiment of the present application provides an apparatus for encoding video data, the apparatus including:

a memory for storing a knowledge base image;

the video encoder is used for encoding the encoding information into a code stream;

when it is determined that the current image to be processed is inter-frame predicted to refer to the knowledge base image, the encoding information includes a second identifier, the first identifier is used for indicating whether a reconstructed pixel value of the current image to be processed copies a pixel value of the knowledge base image, and when the second identifier is a first numerical value, the first identifier is used for indicating the reconstructed pixel value of the current image to be processed to copy a pixel value of the knowledge base image.

In a ninth aspect, an embodiment of the present application provides an encoding apparatus, including: a non-volatile memory and a processor coupled to each other, the processor calling program code stored in the memory to perform part or all of the steps of any one of the methods of the second aspect.

In a tenth aspect, an embodiment of the present application provides a decoding apparatus, including: a non-volatile memory and a processor coupled to each other, the processor calling program code stored in the memory to perform part or all of the steps of any one of the methods of the first aspect.

In an eleventh aspect, embodiments of the present application provide a computer-readable storage medium storing program code, where the program code includes instructions for performing some or all of the steps of any one of the methods of the first aspect or the second aspect.

In a twelfth aspect, embodiments of the present application provide a computer program product, which when run on a computer, causes the computer to perform part or all of the steps of any one of the methods of the first aspect or the second aspect.

It should be understood that the second to twelfth aspects of the present application are the same as or similar to the technical solutions of the first aspect of the present application, and the beneficial effects achieved by the aspects and the corresponding possible embodiments are similar, and are not described in detail again.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the background art of the present application, the drawings required to be used in the embodiments or the background art of the present application will be described below.

FIG. 1A is a block diagram of an example of a video encoding and decoding system 10 for implementing embodiments of the present application;

FIG. 1B is a block diagram of an example of a video coding system 40 for implementing embodiments of the present application;

FIG. 2 is a block diagram of an example structure of an encoder 20 for implementing embodiments of the present application;

FIG. 3 is a block diagram of an example structure of a decoder 30 for implementing embodiments of the present application;

FIG. 4 is a block diagram of an example of a video coding apparatus 400 for implementing an embodiment of the present application;

FIG. 5 is a block diagram of another example of an encoding device or a decoding device for implementing embodiments of the present application;

FIG. 6 is a schematic diagram of a reference relationship between a random access segment and a knowledge base image for implementing an embodiment of the present application;

FIG. 7 is a flowchart illustrating a video image decoding method for implementing an embodiment of the present application;

FIG. 8A is a schematic diagram of a structure of a syntax element in a bitstream for implementing an embodiment of the present application;

FIG. 8B is a schematic diagram of another syntax element structure in a bitstream for implementing an embodiment of the present application;

FIG. 8C is a schematic diagram of a structure of another syntax element in a bitstream for implementing an embodiment of the present application;

FIG. 9 is a flow chart of a video image encoding method for implementing an embodiment of the present application;

FIG. 10 is a flow chart of another video image decoding method for implementing the embodiments of the present application;

FIG. 11A is a schematic diagram of a structure of another syntax element in a codestream for implementing an embodiment of the present application;

FIG. 11B is a diagram illustrating a structure of another syntax element in a bitstream for implementing an embodiment of the present application;

FIG. 11C is a schematic diagram of a structure of another syntax element in a bitstream for implementing an embodiment of the present application;

FIG. 11D is a diagram illustrating a structure of another syntax element in a bitstream for implementing an embodiment of the present application;

FIG. 12 is a flow chart of another video image encoding method for implementing embodiments of the present application;

fig. 13 is a block diagram of a video image decoding apparatus 1300 for implementing an embodiment of the present application;

fig. 14 is a block diagram of a video image encoding apparatus 1400 for implementing an embodiment of the present application.

Detailed Description

The embodiments of the present application will be described below with reference to the drawings. In the following description, reference is made to the accompanying drawings which form a part hereof and in which is shown by way of illustration specific aspects of embodiments of the application or in which specific aspects of embodiments of the application may be employed. It should be understood that embodiments of the present application may be used in other ways and may include structural or logical changes not depicted in the drawings. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present application is defined by the appended claims. For example, it should be understood that the disclosure in connection with the described methods may equally apply to the corresponding apparatus or system for performing the methods, and vice versa. For example, if one or more particular method steps are described, the corresponding apparatus may comprise one or more units, such as functional units, to perform the described one or more method steps (e.g., a unit performs one or more steps, or multiple units, each of which performs one or more of the multiple steps), even if such one or more units are not explicitly described or illustrated in the figures. On the other hand, for example, if a particular apparatus is described based on one or more units, such as functional units, the corresponding method may comprise one step to perform the functionality of the one or more units (e.g., one step performs the functionality of the one or more units, or multiple steps, each of which performs the functionality of one or more of the plurality of units), even if such one or more steps are not explicitly described or illustrated in the figures. Further, it is to be understood that features of the various exemplary embodiments and/or aspects described herein may be combined with each other, unless explicitly stated otherwise.

The technical scheme related to the embodiment of the application can be applied to the existing video coding standards (such as H.264, HEVC and the like), and can also be applied to the future video coding standards (such as H.266 standard). The terminology used in the description of the embodiments section of the present application is for the purpose of describing particular embodiments of the present application only and is not intended to be limiting of the present application. Some concepts that may be involved in embodiments of the present application are briefly described below.

Video coding generally refers to processing a sequence of pictures that form a video or video sequence. In the field of video coding, the terms "picture", "frame" or "image" may be used as synonyms. Video encoding as used herein means video encoding or video decoding. Video encoding is performed on the source side, typically including processing (e.g., by compressing) the original video picture to reduce the amount of data required to represent the video picture for more efficient storage and/or transmission. Video decoding is performed at the destination side, typically involving inverse processing with respect to the encoder, to reconstruct the video pictures. Embodiments are directed to video picture "encoding" to be understood as referring to "encoding" or "decoding" of a video sequence. The combination of the encoding part and the decoding part is also called codec (encoding and decoding).

A video sequence comprises a series of images (pictures) which are further divided into slices (slices) which are further divided into blocks (blocks). Video coding performs the coding process in units of blocks, and in some new video coding standards, the concept of blocks is further extended. For example, in the h.264 standard, there is a Macroblock (MB), which may be further divided into a plurality of prediction blocks (partitions) that can be used for predictive coding. In the High Efficiency Video Coding (HEVC) standard, basic concepts such as a Coding Unit (CU), a Prediction Unit (PU), and a Transform Unit (TU) are adopted, and various block units are functionally divided, and a brand new tree-based structure is adopted for description. For example, a CU may be partitioned into smaller CUs according to a quadtree, and the smaller CUs may be further partitioned to form a quadtree structure, where the CU is a basic unit for partitioning and encoding an encoded image. There is also a similar tree structure for PU and TU, and PU may correspond to a prediction block, which is the basic unit of predictive coding. The CU is further partitioned into PUs according to a partitioning pattern. A TU may correspond to a transform block, which is a basic unit for transforming a prediction residual. However, CU, PU and TU are basically concepts of blocks (or image blocks).

For example, in HEVC, a CTU is split into multiple CUs by using a quadtree structure represented as a coding tree. A decision is made at the CU level whether to encode a picture region using inter-picture (temporal) or intra-picture (spatial) prediction. Each CU may be further split into one, two, or four PUs according to the PU split type. The same prediction process is applied within one PU and the relevant information is transmitted to the decoder on a PU basis. After the residual block is obtained by applying a prediction process based on the PU split type, the CU may be partitioned into Transform Units (TUs) according to other quadtree structures similar to the coding tree used for the CU. In recent developments of video compression techniques, the coding blocks are partitioned using Quad-tree and binary tree (QTBT) partitions to partition frames. In the QTBT block structure, a CU may be square or rectangular in shape.

Herein, for convenience of description and understanding, an image block to be encoded in a currently encoded image may be referred to as a current block, e.g., in encoding, referring to a block currently being encoded; in decoding, refers to the block currently being decoded. A decoded image block in a reference picture used for predicting the current block is referred to as a reference block, i.e. a reference block is a block that provides a reference signal for the current block, wherein the reference signal represents pixel values within the image block. A block in the reference picture that provides a prediction signal for the current block may be a prediction block, wherein the prediction signal represents pixel values or sample values or a sampled signal within the prediction block. For example, after traversing multiple reference blocks, a best reference block is found that will provide prediction for the current block, which is called a prediction block.

In the case of lossless video coding, the original video picture can be reconstructed, i.e., the reconstructed video picture has the same quality as the original video picture (assuming no transmission loss or other data loss during storage or transmission). In the case of lossy video coding, the amount of data needed to represent the video picture is reduced by performing further compression, e.g., by quantization, while the decoder side cannot fully reconstruct the video picture, i.e., the quality of the reconstructed video picture is lower or worse than the quality of the original video picture.

Several video coding standards of h.261 belong to the "lossy hybrid video codec" (i.e., the combination of spatial and temporal prediction in the sample domain with 2D transform coding in the transform domain for applying quantization). Each picture of a video sequence is typically partitioned into non-overlapping sets of blocks, typically encoded at the block level. In other words, the encoder side typically processes, i.e., encodes, video at the block (video block) level, e.g., generates a prediction block by spatial (intra-picture) prediction and temporal (inter-picture) prediction, subtracts the prediction block from the current block (currently processed or block to be processed) to obtain a residual block, transforms the residual block and quantizes the residual block in the transform domain to reduce the amount of data to be transmitted (compressed), while the decoder side applies the inverse processing portion relative to the encoder to the encoded or compressed block to reconstruct the current block for representation. In addition, the encoder replicates the decoder processing loop such that the encoder and decoder generate the same prediction (e.g., intra-prediction and inter-prediction) and/or reconstruction for processing, i.e., encoding, subsequent blocks.

The system architecture to which the embodiments of the present application apply is described below. Referring to fig. 1A, fig. 1A schematically shows a block diagram of a video encoding and decoding system 10 to which an embodiment of the present application is applied. As shown in fig. 1A, video encoding and decoding system 10 may include a source device 12 and a destination device 14, source device 12 generating encoded video data, and thus source device 12 may be referred to as a video encoding apparatus. Destination device 14 may decode the encoded video data generated by source device 12, and thus destination device 14 may be referred to as a video decoding apparatus. Various implementations of source apparatus 12, destination apparatus 14, or both may include one or more processors and memory coupled to the one or more processors. The memory can include, but is not limited to, RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures that can be accessed by a computer, as described herein. Source apparatus 12 and destination apparatus 14 may comprise a variety of devices, including desktop computers, mobile computing devices, notebook (e.g., laptop) computers, tablet computers, set-top boxes, telephone handsets such as so-called "smart" phones, televisions, cameras, display devices, digital media players, video game consoles, on-board computers, wireless communication devices, or the like.

Although fig. 1A depicts source apparatus 12 and destination apparatus 14 as separate apparatuses, an apparatus embodiment may also include the functionality of both source apparatus 12 and destination apparatus 14 or both, i.e., source apparatus 12 or corresponding functionality and destination apparatus 14 or corresponding functionality. In such embodiments, source device 12 or corresponding functionality and destination device 14 or corresponding functionality may be implemented using the same hardware and/or software, or using separate hardware and/or software, or any combination thereof.

A communication connection may be made between source device 12 and destination device 14 over link 13, and destination device 14 may receive encoded video data from source device 12 via link 13. Link 13 may comprise one or more media or devices capable of moving encoded video data from source apparatus 12 to destination apparatus 14. In one example, link 13 may include one or more communication media that enable source device 12 to transmit encoded video data directly to destination device 14 in real-time. In this example, source apparatus 12 may modulate the encoded video data according to a communication standard, such as a wireless communication protocol, and may transmit the modulated video data to destination apparatus 14. The one or more communication media may include wireless and/or wired communication media such as a Radio Frequency (RF) spectrum or one or more physical transmission lines. The one or more communication media may form part of a packet-based network, such as a local area network, a wide area network, or a global network (e.g., the internet). The one or more communication media may include routers, switches, base stations, or other apparatuses that facilitate communication from source apparatus 12 to destination apparatus 14.

Source device 12 includes an encoder 20, and in the alternative, source device 12 may also include a picture source 16, a picture preprocessor 18, and a communication interface 22. In one implementation, the encoder 20, the picture source 16, the picture preprocessor 18, and the communication interface 22 may be hardware components of the source device 12 or may be software programs of the source device 12. Described below, respectively:

the picture source 16, which may include or be any kind of picture capturing device, is used for capturing, for example, a real-world picture, and/or any kind of picture or comment generation device (for screen content encoding, some text on the screen is also considered as part of the picture or image to be encoded), such as a computer graphics processor for generating a computer animation picture, or any kind of device for acquiring and/or providing a real-world picture, a computer animation picture (e.g., screen content, a Virtual Reality (VR) picture), and/or any combination thereof (e.g., an Augmented Reality (AR) picture). The picture source 16 may be a camera for capturing pictures or a memory for storing pictures, and the picture source 16 may also include any kind of (internal or external) interface for storing previously captured or generated pictures and/or for obtaining or receiving pictures. When picture source 16 is a camera, picture source 16 may be, for example, an integrated camera local or integrated in the source device; when the picture source 16 is a memory, the picture source 16 may be an integrated memory local or integrated, for example, in the source device. When the picture source 16 comprises an interface, the interface may for example be an external interface receiving pictures from an external video source, for example an external picture capturing device such as a camera, an external memory or an external picture generating device, for example an external computer graphics processor, a computer or a server. The interface may be any kind of interface according to any proprietary or standardized interface protocol, e.g. a wired or wireless interface, an optical interface.

In order to represent color, three color components are typically employed, i.e., the picture may be represented as or contain three sample arrays, e.g., in RBG format or color space, the picture includes corresponding red, green, and blue sample arrays, however, in video coding, each pixel is typically represented in luminance/chrominance format or color space, e.g., for a picture in YUV format, including a luminance component indicated by Y (sometimes also indicated by L) and two chrominance components indicated by U and V.

Picture pre-processor 18 is configured to receive original picture data 17 and perform pre-processing on original picture data 17 to obtain pre-processed picture 19 or pre-processed picture data 19. For example, the pre-processing performed by picture pre-processor 18 may include trimming, color format conversion (e.g., from RGB format to YUV format), toning, or de-noising.

An encoder 20 (or video encoder 20) for receiving the pre-processed picture data 19, processing the pre-processed picture data 19 with a relevant prediction mode (such as the prediction mode in various embodiments herein), thereby providing encoded picture data 21 (structural details of the encoder 20 will be described further below based on fig. 2 or fig. 4 or fig. 5). In some embodiments, the encoder 20 may be configured to perform various embodiments described hereinafter to implement the application of the chroma block prediction method described herein on the encoding side.

A communication interface 22, which may be used to receive encoded picture data 21 and may transmit encoded picture data 21 over link 13 to destination device 14 or any other device (e.g., memory) for storage or direct reconstruction, which may be any device for decoding or storage. Communication interface 22 may, for example, be used to encapsulate encoded picture data 21 into a suitable format, such as a data packet, for transmission over link 13.

Destination device 14 includes a decoder 30, and optionally destination device 14 may also include a communication interface 28, a picture post-processor 32, and a display device 34. Described below, respectively:

communication interface 28 may be used to receive encoded picture data 21 from source device 12 or any other source, such as a storage device, such as an encoded picture data storage device. The communication interface 28 may be used to transmit or receive the encoded picture data 21 by way of a link 13 between the source device 12 and the destination device 14, or by way of any type of network, such as a direct wired or wireless connection, any type of network, such as a wired or wireless network or any combination thereof, or any type of private and public networks, or any combination thereof. Communication interface 28 may, for example, be used to decapsulate data packets transmitted by communication interface 22 to obtain encoded picture data 21.

Both communication interface 28 and communication interface 22 may be configured as a one-way communication interface or a two-way communication interface, and may be used, for example, to send and receive messages to establish a connection, acknowledge and exchange any other information related to a communication link and/or data transfer, such as an encoded picture data transfer.

A decoder 30 (otherwise referred to as decoder 30) for receiving the encoded picture data 21 and providing decoded picture data 31 or decoded pictures 31 (structural details of the decoder 30 will be described further below based on fig. 3 or fig. 4 or fig. 5). In some embodiments, the decoder 30 may be configured to perform various embodiments described hereinafter to implement the application of the chroma block prediction method described herein on the decoding side.

A picture post-processor 32 for performing post-processing on the decoded picture data 31 (also referred to as reconstructed picture data) to obtain post-processed picture data 33. Post-processing performed by picture post-processor 32 may include: color format conversion (e.g., from YUV format to RGB format), toning, trimming or resampling, or any other process may also be used to transmit post-processed picture data 33 to display device 34.

The display device 34 may be or may include any type of display for presenting the reconstructed picture, such as an integrated or external display or monitor, for example, the display may include a liquid crystal display (L CD), an organic light emitting diode (O L ED) display, a plasma display, a projector, a micro L ED display, a liquid crystal on silicon (L CoS), a digital light processor (D L P), or any type of other display.

Although fig. 1A depicts source device 12 and destination device 14 as separate devices, device embodiments may also include the functionality of both source device 12 and destination device 14 or both, i.e., source device 12 or corresponding functionality and destination device 14 or corresponding functionality. In such embodiments, source device 12 or corresponding functionality and destination device 14 or corresponding functionality may be implemented using the same hardware and/or software, or using separate hardware and/or software, or any combination thereof.

It will be apparent to those skilled in the art from this description that the existence and (exact) division of the functionality of the different elements, or source device 12 and/or destination device 14 as shown in fig. 1A, may vary depending on the actual device and application. Source device 12 and destination device 14 may comprise any of a variety of devices, including any type of handheld or stationary device, such as a notebook or laptop computer, a mobile phone, a smartphone, a tablet or tablet computer, a camcorder, a desktop computer, a set-top box, a television, a camera, an in-vehicle device, a display device, a digital media player, a video game console, a video streaming device (e.g., a content service server or a content distribution server), a broadcast receiver device, a broadcast transmitter device, etc., and may not use or use any type of operating system.

Both encoder 20 and decoder 30 may be implemented as any of a variety of suitable circuits, such as one or more microprocessors, Digital Signal Processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), discrete logic, hardware, or any combinations thereof. If the techniques are implemented in part in software, an apparatus may store instructions of the software in a suitable non-transitory computer-readable storage medium and may execute the instructions in hardware using one or more processors to perform the techniques of this disclosure. Any of the foregoing, including hardware, software, a combination of hardware and software, etc., may be considered one or more processors.

In some cases, the video encoding and decoding system 10 shown in fig. 1A is merely an example, and the techniques of this application may be applicable to video encoding settings (e.g., video encoding or video decoding) that do not necessarily involve any data communication between the encoding and decoding devices. In other examples, the data may be retrieved from local storage, streamed over a network, and so on. A video encoding device may encode and store data to a memory, and/or a video decoding device may retrieve and decode data from a memory. In some examples, the encoding and decoding are performed by devices that do not communicate with each other, but merely encode data to and/or retrieve data from memory and decode data.

Referring to fig. 1B, fig. 1B is an illustrative diagram of an example of a video coding system 40 including the encoder 20 of fig. 2 and/or the decoder 30 of fig. 3, according to an example embodiment. Video coding system 40 may implement a combination of the various techniques of the embodiments of the present application. In the illustrated embodiment, video coding system 40 may include an imaging device 41, an encoder 20, a decoder 30 (and/or a video codec implemented by logic circuitry 47), an antenna 42, one or more processors 43, one or more memories 44, and/or a display device 45.

As shown in fig. 1B, the imaging device 41, the antenna 42, the logic 47, the encoder 20, the decoder 30, the processor 43, the memory 44, and/or the display device 45 can communicate with each other. As discussed, although video coding system 40 is depicted with encoder 20 and decoder 30, in different examples video coding system 40 may include only encoder 20 or only decoder 30.

In some instances, antenna 42 may be used to transmit or receive an encoded bitstream of video data. Additionally, in some instances, display device 45 may be used to present video data. In some examples, the logic 47 may include application-specific integrated circuit (ASIC) logic, a graphics processor, a general-purpose processor, or the like. Video decoding system 40 may also include an optional processor 43, which optional processor 43 similarly may include application-specific integrated circuit (ASIC) logic, a graphics processor, a general-purpose processor, or the like. In some examples, the logic 47 may be implemented in hardware, such as video encoding specific hardware, and the processor 43 may be implemented in general purpose software, an operating system, and so on. In addition, the Memory 44 may be any type of Memory, such as a volatile Memory (e.g., Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), etc.) or a nonvolatile Memory (e.g., flash Memory, etc.), and the like. In a non-limiting example, storage 44 may be implemented by a speed cache memory. In some instances, logic circuitry 47 may access memory 44 (e.g., to implement an image buffer). In other examples, logic 47 may include memory (e.g., cache, etc.) for implementing an image buffer, etc.

In some examples, encoder 20 implemented with logic circuitry may include an image buffer (e.g., implemented with logic circuitry 47 or memory 44) and a graphics processing unit (e.g., implemented with logic circuitry 47). The graphics processing unit may be communicatively coupled to the image buffer. The graphics processing unit may include an encoder 20 implemented by logic circuitry 47 to implement the various modules discussed with reference to fig. 2 and/or any other encoder system or subsystem described herein. Logic circuitry may be used to perform various operations discussed herein.

In some examples, decoder 30 may be implemented by logic circuitry 47 in a similar manner to implement the various modules discussed with reference to decoder 30 of fig. 3 and/or any other decoder system or subsystem described herein. In some examples, logic implemented decoder 30 may include an image buffer (implemented by processing unit 2820 or memory 44) and a graphics processing unit (implemented by logic 47, for example). The graphics processing unit may be communicatively coupled to the image buffer. The graphics processing unit may include a decoder 30 implemented by logic circuitry 47 to implement the various modules discussed with reference to fig. 3 and/or any other decoder system or subsystem described herein.

In some instances, antenna 42 may be used to receive an encoded bitstream of video data. As discussed, the encoded bitstream may include data related to the encoded video frame, indicators, index values, mode selection data, etc., discussed herein, such as data related to the encoding partition (e.g., transform coefficients or quantized transform coefficients, (as discussed) optional indicators, and/or data defining the encoding partition). Video coding system 40 may also include a decoder 30 coupled to antenna 42 and used to decode the encoded bitstream. The display device 45 is used to present video frames.

It should be understood that for the example described with reference to encoder 20 in the embodiments of the present application, decoder 30 may be used to perform the reverse process. With respect to signaling syntax elements, decoder 30 may be configured to receive and parse such syntax elements and decode the associated video data accordingly. In some examples, encoder 20 may entropy encode the syntax elements into an encoded video bitstream. In such instances, decoder 30 may parse such syntax elements and decode the relevant video data accordingly.

It should be noted that the video image encoding method described in the embodiment of the present application occurs at the encoder 20, the video image decoding method described in the embodiment of the present application occurs at the decoder 30, and the encoder 20 and the decoder 30 in the embodiment of the present application may be a video standard protocol such as h.263, h.264, HEVV, MPEG-2, MPEG-4, VP8, VP9, or a codec corresponding to a next generation video standard protocol (e.g., h.266).

Referring to fig. 2, fig. 2 shows a schematic/conceptual block diagram of an example of an encoder 20 for implementing embodiments of the present application. In the example of fig. 2, the encoder 20 includes a residual calculation unit 204, a transform processing unit 206, a quantization unit 208, an inverse quantization unit 210, an inverse transform processing unit 212, a reconstruction unit 214, a buffer 216, a loop filter unit 220, a Decoded Picture Buffer (DPB) 230, a prediction processing unit 260, an entropy coding unit 270, and a bitstream packing unit 280. Prediction processing unit 260 may include inter prediction unit 244, intra prediction unit 254, and mode selection unit 262. Inter prediction unit 244 may include a motion estimation unit and a motion compensation unit (not shown). The encoder 20 shown in fig. 2 may also be referred to as a hybrid video encoder or a video encoder according to a hybrid video codec.

For example, the residual calculation unit 204, the transform processing unit 206, the quantization unit 208, the prediction processing unit 260, and the entropy encoding unit 270 form a forward signal path of the encoder 20, and, for example, the inverse quantization unit 210, the inverse transform processing unit 212, the reconstruction unit 214, the buffer 216, the loop filter 220, the Decoded Picture Buffer (DPB) 230, the prediction processing unit 260 form a backward signal path of the encoder, wherein the backward signal path of the encoder corresponds to a signal path of a decoder (see the decoder 30 in fig. 3).

The encoder 20 receives, e.g., via an input 202, a picture 201 or an image block 203 of a picture 201, e.g., a picture in a sequence of pictures forming a video or a video sequence. Image block 203 may also be referred to as a current picture block or a picture block to be encoded, and picture 201 may be referred to as a current picture or a picture to be encoded (especially when the current picture is distinguished from other pictures in video encoding, such as previously encoded and/or decoded pictures in the same video sequence, i.e., a video sequence that also includes the current picture).

An embodiment of the encoder 20 may comprise a partitioning unit (not shown in fig. 2) for partitioning the picture 201 into a plurality of blocks, e.g. image blocks 203, typically into a plurality of non-overlapping blocks. The partitioning unit may be used to use the same block size for all pictures in a video sequence and a corresponding grid defining the block size, or to alter the block size between pictures or subsets or groups of pictures and partition each picture into corresponding blocks.

In one example, prediction processing unit 260 of encoder 20 may be used to perform any combination of the above-described segmentation techniques.

Like picture 201, image block 203 is also or can be considered as a two-dimensional array or matrix of sample points having sample values, although its size is smaller than picture 201. In other words, the image block 203 may comprise, for example, one sample array (e.g., a luma array in the case of a black and white picture 201) or three sample arrays (e.g., a luma array and two chroma arrays in the case of a color picture) or any other number and/or class of arrays depending on the color format applied. The number of sampling points in the horizontal and vertical directions (or axes) of the image block 203 defines the size of the image block 203.

The encoder 20 as shown in fig. 2 is used to encode a picture 201 block by block, e.g. performing encoding and prediction for each image block 203.

The residual calculation unit 204 is configured to calculate a residual block 205 based on the picture image block 203 and the prediction block 265 (further details of the prediction block 265 are provided below), e.g. by subtracting sample values of the prediction block 265 from sample values of the picture image block 203 sample by sample (pixel by pixel) to obtain the residual block 205 in the sample domain.

The transform processing unit 206 is configured to apply a transform, such as a Discrete Cosine Transform (DCT) or a Discrete Sine Transform (DST), on the sample values of the residual block 205 to obtain transform coefficients 207 in a transform domain. The transform coefficients 207 may also be referred to as transform residual coefficients and represent the residual block 205 in the transform domain.

The transform processing unit 206 may be used to apply integer approximations of DCT/DST, such as the transform specified for HEVC/h.265. Such integer approximations are typically scaled by some factor compared to the orthogonal DCT transform. To maintain the norm of the residual block processed by the forward transform and the inverse transform, an additional scaling factor is applied as part of the transform process. The scaling factor is typically selected based on certain constraints, e.g., the scaling factor is a power of 2 for a shift operation, a trade-off between bit depth of transform coefficients, accuracy and implementation cost, etc. For example, a specific scaling factor may be specified on the decoder 30 side for the inverse transform by, for example, inverse transform processing unit 212 (and on the encoder 20 side for the corresponding inverse transform by, for example, inverse transform processing unit 212), and correspondingly, a corresponding scaling factor may be specified on the encoder 20 side for the forward transform by transform processing unit 206.

Quantization unit 208 is used to quantize transform coefficients 207, e.g., by applying scalar quantization or vector quantization, to obtain quantized transform coefficients 209. Quantized transform coefficients 209 may also be referred to as quantized residual coefficients 209. The quantization process may reduce the bit depth associated with some or all of transform coefficients 207. For example, an n-bit transform coefficient may be rounded down to an m-bit transform coefficient during quantization, where n is greater than m. The quantization level may be modified by adjusting a Quantization Parameter (QP). For example, for scalar quantization, different scales may be applied to achieve finer or coarser quantization. Smaller quantization steps correspond to finer quantization and larger quantization steps correspond to coarser quantization. An appropriate quantization step size may be indicated by a Quantization Parameter (QP). For example, the quantization parameter may be an index of a predefined set of suitable quantization step sizes. For example, a smaller quantization parameter may correspond to a fine quantization (smaller quantization step size) and a larger quantization parameter may correspond to a coarse quantization (larger quantization step size), or vice versa. The quantization may comprise a division by a quantization step size and a corresponding quantization or inverse quantization, e.g. performed by inverse quantization 210, or may comprise a multiplication by a quantization step size. Embodiments according to some standards, such as HEVC, may use a quantization parameter to determine the quantization step size. In general, the quantization step size may be calculated based on the quantization parameter using a fixed point approximation of an equation that includes division. Additional scaling factors may be introduced for quantization and dequantization to recover the norm of the residual block that may be modified due to the scale used in the fixed point approximation of the equation for the quantization step size and quantization parameter. In one example implementation, the inverse transform and inverse quantization scales may be combined. Alternatively, a custom quantization table may be used and signaled from the encoder to the decoder, e.g., in a bitstream. Quantization is a lossy operation, where the larger the quantization step size, the greater the loss.

The inverse quantization unit 210 is configured to apply inverse quantization of the quantization unit 208 on the quantized coefficients to obtain inverse quantized coefficients 211, e.g., to apply an inverse quantization scheme of the quantization scheme applied by the quantization unit 208 based on or using the same quantization step as the quantization unit 208. The dequantized coefficients 211 may also be referred to as dequantized residual coefficients 211, corresponding to transform coefficients 207, although the loss due to quantization is typically not the same as the transform coefficients.

The inverse transform processing unit 212 is configured to apply an inverse transform of the transform applied by the transform processing unit 206, for example, an inverse Discrete Cosine Transform (DCT) or an inverse Discrete Sine Transform (DST), to obtain an inverse transform block 213 in the sample domain. The inverse transform block 213 may also be referred to as an inverse transform dequantized block 213 or an inverse transform residual block 213.

The reconstruction unit 214 (e.g., summer 214) is used to add the inverse transform block 213 (i.e., the reconstructed residual block 213) to the prediction block 265 to obtain the reconstructed block 215 in the sample domain, e.g., to add sample values of the reconstructed residual block 213 to sample values of the prediction block 265.

Optionally, a buffer unit 216 (or simply "buffer" 216), such as a line buffer 216, is used to buffer or store the reconstructed block 215 and corresponding sample values, for example, for intra prediction. In other embodiments, the encoder may be used to use the unfiltered reconstructed block and/or corresponding sample values stored in buffer unit 216 for any class of estimation and/or prediction, such as intra prediction.

For example, an embodiment of encoder 20 may be configured such that buffer unit 216 is used not only to store reconstructed blocks 215 for intra prediction 254, but also for loop filter unit 220 (not shown in fig. 2), and/or such that buffer unit 216 and decoded picture buffer unit 230 form one buffer, for example. Other embodiments may be used to use filtered block 221 and/or blocks or samples from decoded picture buffer 230 (neither shown in fig. 2) as input or basis for intra prediction 254. The decoded picture buffer 230 is also used to store the knowledge base image. The knowledge base will be described in detail later, and will not be described in detail here.

Loop filter unit 220 (or simply "loop filter" 220) is used to filter reconstructed block 215 to obtain filtered block 221, thereby facilitating pixel transitions or improving video quality loop filter unit 220 is intended to represent one or more loop filters, such as a deblocking filter, a sample-adaptive offset (SAO) filter, or other filters, such as a bilateral filter, an adaptive loop filter (A L F), or a sharpening or smoothing filter, or a collaborative filter, although loop filter unit 220 is shown in FIG. 2 as an in-loop filter, in other configurations loop filter unit 220 may be implemented as a post-loop filter.

Embodiments of encoder 20 (correspondingly, loop filter unit 220) may be configured to output loop filter parameters (e.g., sample adaptive offset information), e.g., directly or after entropy encoding by entropy encoding unit 270 or any other entropy encoding unit, e.g., such that decoder 30 may receive and apply the same loop filter parameters for decoding.

Decoded Picture Buffer (DPB) 230 may be a reference picture memory that stores reference picture data for use by encoder 20 in encoding video data. DPB230 may be formed from any of a variety of memory devices, such as Dynamic Random Access Memory (DRAM) including Synchronous DRAM (SDRAM), Magnetoresistive RAM (MRAM), Resistive RAM (RRAM), or other types of memory devices. The DPB230 and the buffer 216 may be provided by the same memory device or separate memory devices. In a certain example, a Decoded Picture Buffer (DPB) 230 is used to store filtered blocks 221. Decoded picture buffer 230 may further be used to store other previous filtered blocks, such as previous reconstructed and filtered blocks 221, of the same current picture or of a different picture, such as a previous reconstructed picture, and may provide the complete previous reconstructed, i.e., decoded picture (and corresponding reference blocks and samples) and/or the partially reconstructed current picture (and corresponding reference blocks and samples), e.g., for inter prediction. In a certain example, if reconstructed block 215 is reconstructed without in-loop filtering, Decoded Picture Buffer (DPB) 230 is used to store reconstructed block 215.

Prediction processing unit 260, also referred to as block prediction processing unit 260, is used to receive or obtain image block 203 (current image block 203 of current picture 201) and reconstructed picture data, e.g., reference samples of the same (current) picture from buffer 216 and/or reference picture data 231 of one or more previously decoded pictures from decoded picture buffer 230, and to process such data for prediction, i.e., to provide prediction block 265, which may be inter-predicted block 245 or intra-predicted block 255.

The mode selection unit 262 may be used to select a prediction mode (e.g., intra or inter prediction mode) and/or a corresponding prediction block 245 or 255 used as the prediction block 265 to calculate the residual block 205 and reconstruct the reconstructed block 215.

Embodiments of mode selection unit 262 may be used to select prediction modes (e.g., from those supported by prediction processing unit 260) that provide the best match or the smallest residual (smallest residual means better compression in transmission or storage), or that provide the smallest signaling overhead (smallest signaling overhead means better compression in transmission or storage), or both. The mode selection unit 262 may be configured to determine a prediction mode based on Rate Distortion Optimization (RDO), i.e., select a prediction mode that provides the minimum rate distortion optimization, or select a prediction mode in which the associated rate distortion at least meets the prediction mode selection criteria.

The prediction processing performed by the example of the encoder 20 (e.g., by the prediction processing unit 260) and the mode selection performed (e.g., by the mode selection unit 262) will be explained in detail below.

As described above, the encoder 20 is configured to determine or select the best or optimal prediction mode from a set of (predetermined) prediction modes. The prediction mode set may include, for example, intra prediction modes and/or inter prediction modes.

The intra prediction mode set may include 35 different intra prediction modes, for example, non-directional modes such as DC (or mean) mode and planar mode, or directional modes as defined in h.265, or may include 67 different intra prediction modes, for example, non-directional modes such as DC (or mean) mode and planar mode, or directional modes as defined in h.266 under development.

In a possible implementation, the set of inter prediction modes may for example comprise a skip (skip) mode and a merge (merge) mode depending on available reference pictures (i.e. at least partially decoded pictures stored in the DBP 230, for example, as described above) and other inter prediction parameters, for example depending on whether the best matching reference block is searched using the entire reference picture or only a part of the reference picture, for example a search window area of an area surrounding the current block, and/or depending on whether pixel interpolation, such as half-pixel and/or quarter-pixel interpolation, is applied, for example. In one example, intra-prediction unit 254 may be used to perform any combination of the inter-prediction techniques described below.

In addition to the above prediction mode, embodiments of the present application may also apply a skip mode and/or a direct mode.

The prediction processing unit 260 may further be configured to partition the image block 203 into smaller block partitions or sub-blocks, for example, by iteratively using quad-tree (QT) partitions, binary-tree (BT) partitions, or triple-tree (TT) partitions, or any combination thereof, and to perform prediction, for example, for each of the block partitions or sub-blocks, wherein mode selection includes selecting a tree structure of the partitioned image block 203 and selecting a prediction mode to apply to each of the block partitions or sub-blocks.

The inter prediction unit 244 may include a Motion Estimation (ME) unit (not shown in fig. 2) and a Motion Compensation (MC) unit (not shown in fig. 2). The motion estimation unit is used to receive or obtain a picture image block 203 (current picture image block 203 of current picture 201) and a decoded picture 231, or at least one or more previously reconstructed blocks, e.g., reconstructed blocks of one or more other/different previously decoded pictures 231, for motion estimation. For example, the video sequence may comprise a current picture and a previously decoded picture 31, or in other words, the current picture and the previously decoded picture 31 may be part of, or form, a sequence of pictures forming the video sequence.

For example, the encoder 20 may be configured to select a reference block from a plurality of reference blocks of the same or different one of a plurality of other pictures and provide the reference picture and/or an offset (spatial offset) between a position (X, Y coordinates) of the reference block and a position of the current block to a motion estimation unit (not shown in fig. 2) as an inter prediction parameter. This offset is also called a Motion Vector (MV).

The motion compensation unit is configured to obtain inter-prediction parameters and perform inter-prediction based on or using the inter-prediction parameters to obtain an inter-prediction block 245. The motion compensation performed by the motion compensation unit (not shown in fig. 2) may involve taking or generating a prediction block based on a motion/block vector determined by motion estimation (possibly performing interpolation to sub-pixel precision). Interpolation filtering may generate additional pixel samples from known pixel samples, potentially increasing the number of candidate prediction blocks that may be used to encode a picture block. Upon receiving the motion vector for the PU of the current picture block, motion compensation unit 246 may locate the prediction block in one reference picture list to which the motion vector points. Motion compensation unit 246 may also generate syntax elements associated with the blocks and video slices for use by decoder 30 in decoding picture blocks of the video slices.

Specifically, the inter prediction unit 244 may transmit a syntax element including an inter prediction parameter (e.g., indication information for selecting an inter prediction mode for current block prediction after traversing a plurality of inter prediction modes) to the entropy encoding unit 270. In a possible application scenario, if there is only one inter prediction mode, the inter prediction parameters may not be carried in the syntax element, and the decoding end 30 can directly use the default prediction mode for decoding. It will be appreciated that the inter prediction unit 244 may be used to perform any combination of inter prediction techniques.

The intra prediction unit 254 is used to obtain, for example, a picture block 203 (current picture block) of the same picture and one or more previously reconstructed blocks, e.g., reconstructed neighboring blocks, to be received for intra estimation. For example, the encoder 20 may be configured to select an intra-prediction mode from a plurality of (predetermined) intra-prediction modes.

Embodiments of encoder 20 may be used to select an intra prediction mode based on optimization criteria, such as based on a minimum residual (e.g., an intra prediction mode that provides a prediction block 255 that is most similar to current picture block 203) or a minimum code rate distortion.

The intra-prediction unit 254 is further configured to determine the intra-prediction block 255 based on the intra-prediction parameters as the selected intra-prediction mode. In any case, after selecting the intra-prediction mode for the block, intra-prediction unit 254 is also used to provide intra-prediction parameters, i.e., information indicating the selected intra-prediction mode for the block, to entropy encoding unit 270. In one example, intra-prediction unit 254 may be used to perform any combination of intra-prediction techniques.

Specifically, the above-described intra prediction unit 254 may transmit a syntax element including an intra prediction parameter (such as indication information of selecting an intra prediction mode for current block prediction after traversing a plurality of intra prediction modes) to the entropy encoding unit 270. In a possible application scenario, if there is only one intra-prediction mode, the intra-prediction parameters may not be carried in the syntax element, and the decoding end 30 may directly use the default prediction mode for decoding.

Entropy coding unit 270 is configured to apply an entropy coding algorithm or scheme (e.g., a variable length coding (V L C) scheme, a context adaptive V L C (context adaptive V L C, CAV L C) scheme, an arithmetic coding scheme, a Context Adaptive Binary Arithmetic Coding (CABAC), syntax-based context-adaptive binary arithmetic coding (SBAC), Probability Interval Partition Entropy (PIPE) coding, or other methods or techniques) to individual or all of quantized residual coefficients 209, inter-frame prediction parameters, intra-frame prediction parameters, and/or entropy coding loop filter parameters (or not) to obtain coded bitstream data that may be output by output 272, e.g., in the form of coded bitstream 21. video decoder 30 may also transmit the coded bitstream data to video decoder 30 or other video bitstream decoder 30 for later retrieval.

The code stream encapsulating unit 280 is configured to, when it is determined that inter-frame prediction is performed on the current image to be processed to refer to the knowledge base image and it is determined that the reconstructed pixel value of the current image to be processed can copy the referred knowledge base image, encode, into a code stream (e.g., a main code stream), encoding information (e.g., a first identifier, a second identifier, a third identifier, etc.) related to how to refer to the knowledge base image, which is required in a process of decoding the current image to be processed, and directly output the encoded code stream through the output 272. When it is determined that the current image to be processed is inter-predicted with reference to the knowledge base image and the reconstructed pixel values of the current image to be processed cannot copy the pixel values of the referenced knowledge base image, the current image is output to the residual calculation unit 204, and the knowledge base image referred to by the current image is output to the prediction processing unit 260 (e.g., the inter prediction unit 244).

For example, the case where the reconstructed pixel value of the current image to be processed can copy the referred knowledge base image includes: the current image to be processed is the same as the reference knowledge base image or the current image to be processed is substantially close to the same as the reference knowledge base image (e.g., the similarity reaches a preset threshold).

For example, in the case where it is determined that the pixel values of the current image to be processed are the same or substantially close to the same as the pixel values of the reference knowledge base image, a first identifier is encoded into the codestream (e.g., the main codestream) indicating that the reconstructed pixel values of the current image to be processed can copy the pixel values of the reference knowledge base image.

Other structural variations of video encoder 20 may be used to encode the video stream. For example, the non-transform based encoder 20 may quantize the residual signal directly without the transform processing unit 206 for certain blocks or frames. In another embodiment, encoder 20 may have quantization unit 208 and inverse quantization unit 210 combined into a single unit.

Specifically, in the embodiment of the present application, the encoder 20 may be used to implement the video image encoding method described in the following embodiments.

It should be understood that other structural variations of the video encoder 20 may be used to encode the video stream. For example, for some image blocks or image frames, video encoder 20 may quantize the residual signal directly without processing by transform processing unit 206 and, correspondingly, without processing by inverse transform processing unit 212; alternatively, for some image blocks or image frames, the video encoder 20 does not generate residual data and accordingly does not need to be processed by the transform processing unit 206, the quantization unit 208, the inverse quantization unit 210, and the inverse transform processing unit 212; alternatively, video encoder 20 may store the reconstructed image block directly as a reference block without processing by filter 220; alternatively, the quantization unit 208 and the inverse quantization unit 210 in the video encoder 20 may be merged together. The loop filter 220 is optional, and in the case of lossless compression coding, the transform processing unit 206, the quantization unit 208, the inverse quantization unit 210, and the inverse transform processing unit 212 are optional. It should be appreciated that the inter prediction unit 244 and the intra prediction unit 254 may be selectively enabled according to different application scenarios.

Referring to fig. 3, fig. 3 shows a schematic/conceptual block diagram of an example of a decoder 30 for implementing embodiments of the present application. Video decoder 30 is operative to receive encoded picture data (e.g., an encoded bitstream) 21, e.g., encoded by encoder 20, to obtain a decoded picture 231. During the decoding process, video decoder 30 receives video data, such as an encoded video bitstream representing picture blocks of an encoded video slice and associated syntax elements, from video encoder 20.

In the example of fig. 3, decoder 30 includes entropy decoding unit 304, inverse quantization unit 310, inverse transform processing unit 312, reconstruction unit 314 (e.g., summer 314), buffer 316, loop filter 320, decoded picture buffer 330, prediction processing unit 360, and decapsulation unit 303. The prediction processing unit 360 may include an inter prediction unit 344, an intra prediction unit 354, and a mode selection unit 362. In some examples, video decoder 30 may perform a decoding pass that is substantially reciprocal to the encoding pass described with reference to video encoder 20 of fig. 2.

Entropy decoding unit 304 is to perform entropy decoding on encoded picture data 21 to obtain, for example, quantized coefficients 309 and/or decoded encoding parameters (not shown in fig. 3), such as any or all of inter-prediction, intra-prediction parameters, loop filter parameters, and/or other syntax elements (decoded). The entropy decoding unit 304 is further for forwarding the inter-prediction parameters, the intra-prediction parameters, and/or other syntax elements to the prediction processing unit 360. Video decoder 30 may receive syntax elements at the video slice level and/or the video block level.

Inverse quantization unit 310 may be functionally identical to inverse quantization unit 110, inverse transform processing unit 312 may be functionally identical to inverse transform processing unit 212, reconstruction unit 314 may be functionally identical to reconstruction unit 214, buffer 316 may be functionally identical to buffer 216, loop filter 320 may be functionally identical to loop filter 220, and decoded picture buffer 330 may be functionally identical to decoded picture buffer 230.

Prediction processing unit 360 may include inter prediction unit 344 and intra prediction unit 354, where inter prediction unit 344 may be functionally similar to inter prediction unit 244 and intra prediction unit 354 may be functionally similar to intra prediction unit 254. The prediction processing unit 360 is typically used to perform block prediction and/or to obtain a prediction block 365 from the encoded data 21, as well as to receive or obtain (explicitly or implicitly) prediction related parameters and/or information about the selected prediction mode from, for example, the entropy decoding unit 304.

When the video slice is encoded as an intra-coded (I) slice, intra-prediction unit 354 of prediction processing unit 360 is used to generate a prediction block 365 for the picture block of the current video slice based on the signaled intra-prediction mode and data from previously decoded blocks of the current frame or picture. When a video frame is encoded as an inter-coded (i.e., B or P) slice, inter prediction unit 344 (e.g., a motion compensation unit) of prediction processing unit 360 is used to generate a prediction block 365 for the video block of the current video slice based on the motion vectors and other syntax elements received from entropy decoding unit 304. For inter prediction, a prediction block may be generated from one reference picture within one reference picture list. Video decoder 30 may construct the reference frame list using default construction techniques based on the reference pictures stored in DPB 330: list 0 and list 1.

Prediction processing unit 360 is used to determine prediction information for the video blocks of the current video slice by parsing the motion vectors and other syntax elements, and to generate a prediction block for the current video block being decoded using the prediction information. In an example of the present application, prediction processing unit 360 uses some of the syntax elements received to determine a prediction mode (e.g., intra or inter prediction) for encoding video blocks of a video slice, an inter prediction slice type (e.g., B-slice, P-slice, or GPB-slice), construction information for one or more of a reference picture list of the slice, a motion vector for each inter-coded video block of the slice, an inter prediction state for each inter-coded video block of the slice, and other information to decode video blocks of a current video slice. In another example of the present disclosure, the syntax elements received by video decoder 30 from the bitstream include receive Adaptive Parameter Set (APS), video parameter set (vps). Syntax elements in one or more of a Sequence Parameter Set (SPS), a Picture Parameter Set (PPS), or a slice header.

Inverse quantization unit 310 may be used to inverse quantize (i.e., inverse quantize) the quantized transform coefficients provided in the bitstream and decoded by entropy decoding unit 304. The inverse quantization process may include using quantization parameters calculated by video encoder 20 for each video block in the video slice to determine the degree of quantization that should be applied and likewise the degree of inverse quantization that should be applied.

Inverse transform processing unit 312 is used to apply an inverse transform (e.g., an inverse DCT, an inverse integer transform, or a conceptually similar inverse transform process) to the transform coefficients in order to produce a block of residuals in the pixel domain.

The reconstruction unit 314 (e.g., summer 314) is used to add the inverse transform block 313 (i.e., reconstructed residual block 313) to the prediction block 365 to obtain the reconstructed block 315 in the sample domain, e.g., by adding sample values of the reconstructed residual block 313 to sample values of the prediction block 365.

Loop filter unit 320 is used (either during or after the encoding cycle) to filter reconstructed block 315 to obtain filtered block 321 to facilitate pixel transitions or improve video quality in one example, loop filter unit 320 may be used to perform any combination of the filtering techniques described below loop filter unit 320 is intended to represent one or more loop filters, such as a deblocking filter, a sample-adaptive offset (SAO) filter, or other filters, such as a bilateral filter, an adaptive loop filter (A L F), or a sharpening or smoothing filter, or a collaborative filter.

Decoded video block 321 in a given frame or picture is then stored in decoded picture buffer 330, which stores reference pictures for subsequent motion compensation. The decoded picture buffer 330 is also used to store the knowledge base image, wherein the knowledge base image is an image decoded from the knowledge base code stream in advance.

And a decapsulation unit 303, configured to parse coding information related to the reference knowledge base image in the main code stream. When it is determined that inter-frame prediction is performed on a current image to be processed to refer to a knowledge base image and a syntax element (such as a first identifier) in a main code stream indicates that a reconstructed pixel value of the current image to be processed copies a pixel value of the knowledge base image, acquiring the pixel value of the knowledge base image referred to by the current image to be processed from a decoded picture buffer 330; the reconstructed pixel value of the current to-be-processed image is determined according to the pixel value of the acquired knowledge base image (for example, the original pixel value of the knowledge base image or the reconstructed pixel value of the knowledge base image) is output through an output 332 as the reconstructed pixel value of the current to-be-processed image).

Decoder 30 is used to output decoded picture 31, e.g., via output 332, for presentation to or viewing by a user.

Other variations of video decoder 30 may be used to decode the compressed bitstream. For example, decoder 30 may generate an output video stream without loop filter unit 320. For example, the non-transform based decoder 30 may directly inverse quantize the residual signal without the inverse transform processing unit 312 for certain blocks or frames. In another embodiment, video decoder 30 may have inverse quantization unit 310 and inverse transform processing unit 312 combined into a single unit.

Specifically, in the embodiment of the present application, the decoder 30 is used to implement the video image decoding method described in the following embodiments.

It should be understood that other structural variations of the video decoder 30 may be used to decode the encoded video bitstream. For example, video decoder 30 may generate an output video stream without processing by filter 320; alternatively, for some image blocks or image frames, the quantized coefficients are not decoded by entropy decoding unit 304 of video decoder 30 and, accordingly, do not need to be processed by inverse quantization unit 310 and inverse transform processing unit 312. Loop filter 320 is optional; and the inverse quantization unit 310 and the inverse transform processing unit 312 are optional for the case of lossless compression. It should be understood that the inter prediction unit and the intra prediction unit may be selectively enabled according to different application scenarios.

It should be understood that, in the encoder 20 and the decoder 30 of the present application, the processing result of a certain link may be further processed and then output to the next link, for example, after the links such as interpolation filtering, motion vector derivation, or loop filtering, the processing result of the corresponding link is further subjected to operations such as Clip or shift.

For example, the motion vector of the control point of the current image block derived according to the motion vector of the adjacent affine coding block, or the derived motion vector of the sub-block of the current image block may be further processed, which is not limited in the present application. For example, the value range of the motion vector is constrained to be within a certain bit width. Assuming that the allowed bit-width of the motion vector is bitDepth, the motion vector ranges from-2 ^ (bitDepth-1) to 2^ (bitDepth-1) -1, where the "^" symbol represents the power. And if the bitDepth is 16, the value range is-32768-32767. And if the bitDepth is 18, the value range is-131072-131071. As another example, the value of the motion vector (e.g., the motion vector MV of four 4x4 sub-blocks within an 8x8 image block) is constrained such that the maximum difference between the integer part of the four 4x4 sub-blocks MV is no more than N pixels, e.g., no more than one pixel.

Referring to fig. 4, fig. 4 is a schematic structural diagram of a video coding apparatus 400 (e.g., a video encoding apparatus 400 or a video decoding apparatus 400) provided by an embodiment of the present application. Video coding apparatus 400 is suitable for implementing the embodiments described herein. In one embodiment, video coding device 400 may be a video decoder (e.g., decoder 30 of fig. 1A) or a video encoder (e.g., encoder 20 of fig. 1A). In another embodiment, video coding device 400 may be one or more components of decoder 30 of fig. 1A or encoder 20 of fig. 1A described above.

Video coding apparatus 400 includes: an ingress port 410 and a reception unit (Rx)420 for receiving data, a processor, logic unit or Central Processing Unit (CPU)430 for processing data, a transmitter unit (Tx)440 and an egress port 450 for transmitting data, and a memory 460 for storing data. Video coding device 400 may also include optical-to-Electrical (EO) components and optical-to-electrical (opto) components coupled with ingress port 410, receiver unit 420, transmitter unit 440, and egress port 450 for egress or ingress of optical or electrical signals.

The processor 430 is implemented by hardware and software. Processor 430 may be implemented as one or more CPU chips, cores (e.g., multi-core processors), FPGAs, ASICs, and DSPs. Processor 430 is in communication with inlet port 410, receiver unit 420, transmitter unit 440, outlet port 450, and memory 460. Processor 430 includes a coding module 470 (e.g., encoding module 470 or decoding module 470). The encoding/decoding module 470 implements embodiments disclosed herein to implement the chroma block prediction methods provided by embodiments of the present application. For example, the encoding/decoding module 470 implements, processes, or provides various encoding operations. Accordingly, substantial improvements are provided to the functionality of the video coding apparatus 400 by the encoding/decoding module 470 and affect the transition of the video coding apparatus 400 to different states. Alternatively, the encode/decode module 470 is implemented as instructions stored in the memory 460 and executed by the processor 430.

The memory 460, which may include one or more disks, tape drives, and solid state drives, may be used as an over-flow data storage device for storing programs when such programs are selectively executed, and for storing instructions and data that are read during program execution. The memory 460 may be volatile and/or nonvolatile, and may be Read Only Memory (ROM), Random Access Memory (RAM), random access memory (TCAM), and/or Static Random Access Memory (SRAM).

Referring to fig. 5, fig. 5 is a simplified block diagram of an apparatus 500 that may be used as either or both of source device 12 and destination device 14 in fig. 1A according to an example embodiment. Apparatus 500 may implement the techniques of this application. In other words, fig. 5 is a schematic block diagram of an implementation manner of an encoding apparatus or a decoding apparatus (simply referred to as a decoding apparatus 500) of the embodiment of the present application. Among other things, the decoding device 500 may include a processor 510, a memory 530, and a bus system 550. Wherein the processor is connected with the memory through the bus system, the memory is used for storing instructions, and the processor is used for executing the instructions stored by the memory. The memory of the coding device stores program code, and the processor may call the program code stored in the memory to perform various video image encoding or decoding methods described herein. To avoid repetition, it is not described in detail here.

In the embodiment of the present application, the processor 510 may be a Central Processing Unit (CPU), and the processor 510 may also be other general-purpose processors, Digital Signal Processors (DSP), Application Specific Integrated Circuits (ASIC), Field Programmable Gate Arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and so on. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 530 may include a Read Only Memory (ROM) device or a Random Access Memory (RAM) device. Any other suitable type of memory device may also be used for memory 530. Memory 530 may include code and data 531 to be accessed by processor 510 using bus 550. Memory 530 may further include an operating system 533 and application programs 535, the application programs 535 including at least one program that allows processor 510 to perform the video encoding or decoding methods described herein, and in particular the video image encoding or decoding methods described herein. For example, the application programs 535 may include applications 1 through N, which further include a video encoding or decoding application (simply a video coding application) that performs the video encoding or decoding methods described herein.

The bus system 550 may include a power bus, a control bus, a status signal bus, and the like, in addition to a data bus. For clarity of illustration, however, the various buses are designated in the figure as bus system 550.

Optionally, the translator device 500 may also include one or more output devices, such as a display 570. In one example, the display 570 may be a touch-sensitive display that incorporates a display with a touch-sensitive unit operable to sense touch input. A display 570 may be connected to the processor 510 via the bus 550.

The following description is directed to several technical concepts related to the present application.

1) Random access fragment

In video sequence processing, in order for an encoded video sequence to support a random access function, the video sequence is divided into a plurality of segments having a random access function (referred to simply as random access segments). Such as: a video sequence comprises at least one random access segment, each random access segment comprising a random access image and a plurality of non-random access images. Wherein pictures in one random access segment may be intra-coded or inter-coded using inter-prediction with reference to other pictures in the video sequence.

2) Knowledge base

In order to mine and utilize the information of mutual reference of images among a plurality of random access segments during encoding, a knowledge base encoding scheme introduces a knowledge base image (or a knowledge image for short), the knowledge base image is an image outside an image set required to be displayed in a random access segment to which a current image belongs and a random access segment which is closest to the current image in the random access segments, and the knowledge image serves as a reference image to provide reference for an image to be encoded or an image to be decoded. The database storing the above-described set of knowledge base images may be referred to as a knowledge base. In addition, the method for encoding and decoding a picture in a video with reference to at least one knowledge base picture can be called a knowledge-base-based video encoding (english).

In order to eliminate redundant information between random access segments, a knowledge base image combines a plurality of random access segments with related information over a large time span, and eliminates the redundant information between the plurality of random access segments.

3) Reference picture set (rps)

The reference image set may be composed of information about images to which the current image to be processed is referred. The reference image set may include information of the reference non-knowledge base image and may also include information of the knowledge base image. When the reference image set comprises the knowledge base image, the current image to be processed can adopt a knowledge base-based video coding and decoding method by referring to the knowledge base image.

The reference image set may also be referred to as a reference configuration set (rcs). The number of reference images, and the number of knowledge base images in the reference images included in the reference configuration set, etc. may be included in rcs. For example, rcs indicates whether the ith image is a knowledge base image, the number of the ith image, and so on.

4) Code stream of knowledge base

When a video sequence is coded by adopting video coding based on a knowledge base, two code streams are generated, wherein one code stream comprises knowledge base image coding and can be called a knowledge layer code stream, and the other code stream comprises video sequence each frame image reference knowledge base image coding and can be called a main code stream. In addition, the knowledge base image may be repeatedly referenced by random access segments of multiple host streams. For example, fig. 6 shows a reference relationship between a random access segment to which a main stream image obtained by a video coding method used for a knowledge base belongs and a knowledge base image, where each knowledge image is referred to by at least two discontinuous random access segments.

When the video coding and decoding are carried out based on the knowledge base, at least one image is selected from the knowledge base corresponding to the image to be processed as a reference image of the image to be processed aiming at the current image to be processed. The reference picture is intra-coded, thereby obtaining encoded data of the reference picture. And reconstructing according to the encoded data of the reference image to obtain a reconstructed image of the reference image, and performing interframe coding on the image to be processed according to the reconstructed image of the reference image to obtain the encoded data of the image to be processed. And sending the code stream data of the reference image as a knowledge layer code stream to a decoding end. And sending the code stream data of the image to be processed to a decoding end as a main code stream. After receiving the main code stream of the current image to be processed, the decoding end determines the image in the reference knowledge base image set as a reference image, reconstructs the reference knowledge base image, and performs interframe decoding on the image to be processed based on the reconstructed knowledge base image to obtain a reconstructed pixel value of the image to be processed. When the image to be processed of the main code stream is decoded, if the image to be processed refers to a certain knowledge base image in the knowledge base, the image to be processed in the main code stream can be decoded only after the knowledge base image in the knowledge layer code stream is decoded. The knowledge base image may be an image in a video sequence to be processed, and the acquired knowledge base image may also be an image obtained by modeling an image in the video sequence to be processed and an image synthesized by the image in the video sequence to be processed. That is to say the referenced knowledge-base image selected for the current image to be processed may be the same or nearly the same as the pixel values of the current image to be processed, in this case, after the reference knowledge base image is coded and decoded, it is not necessary to additionally code and decode the image to be processed in the main code stream, therefore, in the existing video encoding and decoding method based on the knowledge base, in the case that the pixel value of the referenced knowledge base image selected for the current image to be processed may be the same as the pixel value of the current image to be processed, or the pixel values of the referenced knowledge base image of the current image selection to be processed may be substantially nearly identical to the pixel values of the current image to be processed, after the reference image in the code stream of the encoding/decoding knowledge base, the mode of further encoding/decoding the video image in the main code stream has redundancy.

Based on this, the application provides a video image encoding and decoding method and device, under the condition that the pixel value of the reference knowledge base image selected by the current image to be processed may be the same or close to the same as the pixel value of the current image to be processed, after the reference knowledge base image is encoded and decoded, the image to be processed in the main code stream is not encoded and decoded additionally, but the decoded data of the image to be processed in the main code stream is determined based on the decoded data of the reference knowledge base image which is simply copied, so that the existing redundant encoding mode can be avoided, and transmission resources are saved. The method and the device are based on the same inventive concept, and because the principles of solving the problems of the method and the device are similar, the implementation of the device and the method can be mutually referred, and repeated parts are not repeated.

In the present application, "at least one" means one or more, "and" a plurality "means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone, wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple.

The video image decoding and encoding method provided by the embodiment of the application is suitable for various application scenes, and the following examples illustrate two modes adopted in the application scenes. The first application scenario is a scenario applied to comply with an audio video coding standard (AVS), and the second application scenario is a scenario applied to comply with High Efficiency Video Coding (HEVC) or multifunctional video coding (VVC).

The video image decoding and encoding method provided by the present application is described in detail below from the decoding side with reference to the accompanying drawings. When decoding is implemented, it may be specifically implemented by the decoder 30, or by the decapsulation unit 303 and the DPB330 in the decoder, or by a processor. When the encoding is implemented, the encoding may be implemented by the encoder 20, or implemented by the bitstream packing unit 280 and the DPB230 in the decoder.

A description is given to a video image decoding method in a first application scenario, which is shown in fig. 7.

S701, when the current image to be processed is determined to be inter-frame prediction reference knowledge base image, analyzing the first identification from the code stream. S702a or S702b or S705 is performed.

The first identifier is used for indicating whether the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image. For example, the first flag may be represented by a syntax element copy _ rec _ texture _ picture _ flag in standard text or code, for example, when the syntax element copy _ rec _ texture _ picture _ flag is 1, the flag indicates that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image, and when the syntax element copy _ rec _ texture _ picture _ flag is 0, the flag indicates that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image.

Illustratively, the first identifier may be carried in a slice header (e.g., slice _ segment _ header), a picture header (e.g., inter _ picture _ header), or a sequence header.

For example, the pixel value of the knowledge base image may be a reconstructed pixel value of the knowledge base image or an original pixel value of the knowledge base image, which is not particularly limited in the embodiment of the present application.

The copy operation described in the embodiments of the present application is not limited to conventional direct copy. The following examples illustrate several copies referred to in the examples of this application:

example 2, copying makes the prediction pixel value of the current image to be processed identical to the pixel value of the knowledge image to which the current image to be processed refers, and obtains the reconstructed pixel value of the current image to be processed by combining (e.g., superimposing, etc.) the prediction pixel value of the current image to be processed and the prediction residual of the current image to be processed.

Example 3, copying is performed such that the predicted pixel value of the current image to be processed is identical to the reconstructed pixel value of the knowledge image referred to by the current image to be processed, and the reconstructed pixel value of the current image to be processed is obtained by combining the predicted pixel value of the current image to be processed and post-processing information (e.g., filtered information) of the current image to be processed.

In the embodiment of the present application, only one knowledge base image that can be referred to by the current image to be processed may exist, in other words, only one available knowledge base image may exist in the external knowledge base at any time. In this case, S702a, when the first flag indicates that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image, acquires the pixel value of the knowledge base image referred to by the current image to be processed. S704 is performed.

Of course, there may also be multiple knowledge base images that can be referred to by the current image to be processed in the knowledge base, in this case, S702b is executed, and when the first identifier indicates that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image, a second identifier is parsed from the code stream, where the second identifier indicates the knowledge base image referred to by the current image to be processed. S703 is performed.

It should be understood that S702a and S702b are examples of two different cases of first identifier reference, respectively.

And S703, acquiring the pixel value of the knowledge base image indicated by the second identifier. S704 is performed. For example, the second identifier may be an index of the knowledge base image to which the current image to be processed refers.

Illustratively, the second flag may be represented by a syntax element copied _ library _ picture _ idx _ in _ rcs in standard text or code.

S704, determining a reconstruction pixel value of the current image to be processed according to the acquired pixel value of the knowledge base image.

In step S704, for example, the obtained pixel value of the knowledge base image may be used as the pixel value of the current image to be processed, or the pixel value of the current knowledge base image and the prediction residual of the current image to be processed may be jointly determined (for example, superimposed) to obtain a reconstructed pixel value of the current image to be processed, and for example, the pixel value of the current knowledge base image may be used as the predicted pixel value of the current image to be processed, and then the predicted pixel value of the current image to be processed and post-processing information (for example, information after filtering) of the current image to be processed are jointly obtained to obtain the reconstructed pixel value of the current image to be processed.

S705, when the first identification indicates that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image, the reconstructed pixel value of the current image to be processed is obtained in a non-copy mode by using the referred knowledge base image.

In addition, in step S705, it may be determined that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image in another manner: and when the first decoded identifier does not exist in the code stream, determining that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image, and acquiring the reconstructed pixel value of the current image to be processed in a non-copy mode by using the referenced knowledge base image.

The non-copy manner may be a manner based on motion compensation (e.g., block division, motion compensation, merge, quantization, etc.) to obtain a reconstructed pixel value of the current image to be processed, which is not limited in this application.

In the embodiment of the present application, when determining whether inter-frame prediction is performed on a current image to be processed with reference to a knowledge base image, the inter-frame prediction may be performed on the current image to be processed with reference to the knowledge base image in a variety of ways.

In the first mode, a fourth identifier is parsed from a code stream, the fourth identifier is a syntax element of an image level, and the fourth identifier indicates whether inter-frame prediction is performed on a current image to be processed to refer to a knowledge base image.

For example, the fourth flag may be represented by a syntax element reference _ to _ feature _ picture _ flag in the standard text or code, for example, when the reference _ to _ feature _ picture _ flag is 1, the reference is used to indicate that the current picture to be processed is inter-predicted to refer to the knowledge base picture, and when the reference _ to _ feature _ picture _ flag is 0, the reference is used to indicate that the current picture to be processed is inter-predicted to not refer to the knowledge base picture.

In a second mode, a fifth identifier is analyzed from a code stream, the fifth identifier is a sequence level syntax element, the fifth identifier indicates whether inter-frame prediction is performed on a video sequence where a current image to be processed refers to a knowledge base image, and when the fifth identifier indicates that inter-frame prediction is performed on the video sequence where the current image to be processed refers to the knowledge base image, whether inter-frame prediction is performed on the current image to be processed refers to the knowledge base image is determined based on a reference image configuration set analyzed from the code stream.

For example, the fifth flag in the standard text or code may be represented by a syntax element texture _ picture _ enable _ flag, for example, when texture _ picture _ enable _ flag is 1, it indicates that inter-prediction is performed on the video sequence where the current picture to be processed is located, and when texture _ picture _ enable _ flag is 0, it indicates that inter-prediction is performed on the video sequence where the current picture to be processed is located, and does not refer to the knowledge base picture.

And in the third mode, a reference image configuration set is analyzed from the code stream, and whether the current image to be processed is subjected to inter-frame prediction to refer to a knowledge base image or not is determined based on the reference image configuration set.

And in the fourth mode, a fifth identifier is analyzed from the code stream, wherein the fifth identifier is a sequence level syntax element and indicates whether inter-frame prediction is performed on a video sequence where the current image to be processed refers to a knowledge base image. For example, when the fifth identifier indicates that inter-frame prediction is performed on the video sequence in which the current image to be processed is located, it is determined that inter-frame prediction is performed on the current image to be processed.

As an example, the present example describes some syntax elements of a video image decoding method when determining whether inter prediction is performed on a current image to be processed with reference to a knowledge base image in a first manner, as shown in table 1-1.

TABLE 1-1

In table 1-1, reference _ to _ library _ picture _ flag corresponds to the fourth flag. copy _ rec _ texture _ picture _ flag corresponds to the first flag, and copy _ texture _ picture _ idx _ in _ rcs corresponds to the second flag.

When the reference _ to _ texture _ picture _ flag is parsed from the bitstream (for example, 1-bit flag), and when the reference _ to _ texture _ picture _ flag is equal to 1, indicating that an inter-prediction reference knowledge base picture is performed on the current picture to be processed, parsing the copy _ rec _ texture _ picture _ flag (for example, 1-bit flag) from the bitstream, when the copy _ rec _ texture _ picture _ flag is equal to 1, indicating that a reconstructed pixel value of the current picture is not obtained by using a prediction compensation-based method, directly copying a pixel value of a reference knowledge picture thereof, and when the copy _ rec _ texture _ picture _ flag is equal to 0, indicating that a reconstructed pixel value of the current picture is not directly copied to a reconstructed pixel value of a reference picture thereof, obtaining a reconstructed pixel value of the current picture to be processed by using a motion compensation mode, when the current picture to be processed does not include a motion compensation flag element 350, and when the current picture to be processed does not include a motion compensation flag element flag, the current picture to be processed is equal to 850.

It should be understood that, in the embodiment of the present application, one way is to explicitly transmit a copy _ rec _ texture _ picture _ flag, where when the copy _ rec _ texture _ picture _ flag is equal to 1, it indicates that the current image reconstruction pixel value copies the pixel value of the knowledge image to which the current image reconstruction pixel value refers, and when the copy _ rec _ texture _ picture _ flag is equal to 0, it indicates that the current image reconstruction pixel value does not copy the pixel value of the knowledge image to which the current image reconstruction pixel value refers. The other mode is to implicitly transmit a copy _ rec _ texture _ picture _ flag, when the reconstructed pixel value of the current image to be processed copies the pixel value of the reference knowledge image, the copy _ rec _ texture _ picture _ flag exists in the code stream, and when the reconstructed pixel value of the current image to be processed does not copy the pixel value of the reference knowledge image, the copy _ rec _ texture _ picture _ flag does not exist in the code stream.

In addition, when display transmission is adopted, in the embodiment of the present application, the element of CopyRec L ibrary picture flag may not be configured, and if (CopyRec L ibrary picture flag ═ 0) in table 1-1 may represent if (copy _ rec _ library _ picture _ flag ═ 0).

When copy _ rec _ texture _ picture _ flag is equal to 0, the copied _ texture _ picture _ idx _ in _ rcs is parsed from the codestream, and the copied _ texture _ picture _ idx _ in _ rcs may be a fixed-length unsigned integer (e.g., 3 bits, 4 bits), indicating an index of a knowledge base image referenced by the current image to be processed in a reference image configuration set (rcs). And acquiring the pixel value of the knowledge base image of which the index corresponds to the reference to determine the reconstructed pixel value of the current image to be processed.

For example, the structure of part of the syntax elements in table 1-1 above in the bitstream can be seen in fig. 8A. reference _ to _ texture _ picture _ flag and copy _ rec _ texture _ picture _ flag are in the picture header.

It should be understood that the AVS may or may not include a slice header, where a slice header is included, but the slice header is one level lower than the image header. Illustratively, the information at the image level is mainly included in the image header, and thus the slice header may not be used and may be considered to be in the image data.

As an example, the present example describes some syntax elements of a video image decoding method when determining whether inter prediction is performed on a current image to be processed with reference to a knowledge base image in a second manner, as shown in tables 1-2 and tables 1-3.

Tables 1 to 2

Tables 1 to 3

In tables 1-2 and tables 1-3, the library _ picture _ enable _ flag corresponds to the fifth flag. copy _ rec _ texture _ picture _ flag corresponds to the first flag, and copy _ texture _ picture _ idx _ in _ rcs corresponds to the second flag.

When the syntax _ picture _ enable _ flag is equal to 1, the syntax structure corresponding to table 1-3 is decoded.

The picture reconstruction method includes that a reference picture configuration set (for example, a partial syntax structure shown in tables 1-4 below) used by a current picture to be processed is obtained, for example, when a value of an is _ texture _ index _ flag [ i ] [ j ] of a jth reference picture in an ith rcs used by the current picture to be processed is 1, a value of a ReferenceTo L parapherpiceidflag of the current picture to be processed is 1, when values of an is _ texture _ index _ flag [ i ] [ j ] of all jth reference pictures in an ith rcs used by the current picture to be processed are 0, a value of a ReferenceTo L ibraripiptureflag of the current picture to be processed is 0, a value of a ReferenceTo L parapherflag flag is indicative of that the current picture to be processed does not include a reference picture reconstruction mode required to reconstruct a reconstructed from a current picture map _ texture _ flag.

For example, the structure of part of the syntax elements in tables 1-2 and 1-3 in the bitstream can be seen in fig. 8B. copy _ rec _ texture _ picture _ flag is in the picture header and texture _ picture _ enable _ flag is in the sequence header.

Tables 1 to 4

As an example, the present example describes a part of syntax elements of a video image decoding method when determining whether inter prediction is performed on a current image to be processed with reference to a knowledge base image in a third manner, which can be seen from tables 1 to 3 and tables 1 to 4. The syntax element of the video picture decoding method corresponding to the second way is distinguished in that the texture _ picture _ enable _ flag is not included at the sequence level. After the syntax _ picture _ enable _ flag does not need to be decoded, the syntax elements in tables 1 to 3 are decoded, and detailed description is omitted here.

For example, the structure of a part of syntax elements corresponding to the third method in the code stream can be seen in fig. 8C. copy _ rec _ library _ picture _ flag is in the picture header.

As an example, the present example describes a part of syntax elements of a video image decoding method when determining whether inter prediction is performed on a current image to be processed with reference to a knowledge base image in a fourth manner, which can be seen from tables 1 to 5.

Tables 1 to 5

In tables 1 to 5, the library _ picture _ enable _ flag corresponds to the fifth flag. copy _ rec _ texture _ picture _ flag corresponds to the first flag, and copy _ texture _ picture _ idx _ in _ rcs corresponds to the second flag.

When the texture _ picture _ enable _ flag is parsed from the code stream, and when the texture _ picture _ enable _ flag is 1, indicating that a video sequence in which the current picture to be processed is located refers to an inter-prediction reference knowledge base picture, parsing a copy _ rec _ texture _ picture _ flag (e.g., 1-bit flag) from the code stream, where copy _ rec _ texture _ picture _ flag is 1 indicates that a reconstructed pixel value of the current picture is not obtained by using a prediction compensation-based method, directly copying a pixel value of a reference knowledge picture, and when the texture _ rec _ texture _ picture _ flag is 0, indicating that a reconstructed pixel value of the current picture is not directly copied, a reconstructed pixel value of a reference picture may be obtained by a motion compensation mode, and when the texture _ flag is not described by the motion compensation table 362, the reconstructed pixel value of the current picture to be processed does not include a value corresponding to the texture _ flag 2, and when the texture _ flag is not described as a texture _ flag, the current picture to be processed no longer includes a value corresponding to a flag, and a subsequent motion compensation flag.

Illustratively, the structure of the partial syntax elements in tables 1 to 5 above in the bitstream is similar to the structure of the syntax elements corresponding to the second mode in the bitstream, where copy _ rec _ texture _ picture _ flag is in the picture header and texture _ picture _ enable _ flag is in the sequence header.

The following describes a video image encoding method in a first application scenario. For example, referring to fig. 9, only step S902 may be included. Optionally, S901 and S902 may also be included.

And S901, determining the coding information of the current image block to be processed.

S902, coding information into a code stream, wherein the coding information is used for providing reference information and a using method of the reference information for a decoding end so as to recover a reconstructed pixel value of a current image to be processed; when the current image to be processed is determined to be inter-frame predicted to refer to the knowledge base image, the coding information comprises a first identifier, and the first identifier is used for indicating whether the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image.

The first flag is a first value when the pixel value of the current to-be-processed image is the same as the pixel value of the reference knowledge base image, or when the pixel value of the current to-be-processed image is substantially close to the same as the pixel value of the reference knowledge base image (for example, the similarity between the current to-be-processed image and the reference knowledge base image reaches a preset threshold). The following description will be given by taking a case where the pixel value of the current image to be processed is the same as the pixel value of the reference knowledge base image as an example.

Illustratively, when the first value is 1 and the copy _ rec _ library _ picture _ flag value is 1, all subsequent syntax elements related to motion compensation of the current picture to be processed do not need to be coded in the bitstream at this time.

Illustratively, when the first identifier is a first numerical value, a second identifier is further included in the encoded information, and the second identifier is used for indicating a knowledge base image referred by the current image to be processed; wherein the pixel value of the knowledge base image indicated by the second identifier is used for determining a reconstructed pixel value of the current image to be processed.

Illustratively, the second identifier is located after the first identifier.

Illustratively, when the first identifier is a second numerical value, other identifiers for indicating that the reconstructed pixel value of the current image to be processed is determined by a non-copy method may also be included in the encoded information; wherein the first identifier is a second numerical value to indicate that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image. Illustratively, the second value may be 0. When the copy _ rec _ texture _ picture _ flag value is 0, syntax elements related to motion compensation of the current image to be processed need to be coded into the code stream at this time. In this embodiment of the present application, it may further be indicated that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image by: and when the code stream does not comprise the first identifier, indicating that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image. Further, the encoded information may further include other identifiers for indicating that the reconstructed pixel value of the current image to be processed is determined by a non-copy method.

In one example, a fourth identifier may be further included in the encoding information, where the fourth identifier is a syntax element of a picture level, and the fourth identifier is used to indicate whether inter-prediction is performed on a current picture to be processed with reference to a knowledge base picture.

This example corresponds to the coding scheme corresponding to the decoding scheme of the first scheme.

Specifically, when it is determined that inter-frame prediction is performed on a current image to be processed to refer to a knowledge base image, the coding information includes a fourth identifier, the fourth identifier is used for indicating whether inter-frame prediction is performed on the current image to be processed to refer to the knowledge base image, and when the fourth identifier indicates that inter-frame prediction is performed on the current image to be processed to refer to the knowledge base image, the coding information includes the first identifier; when the pixel value of the current image to be processed is the same or substantially close to the same as the pixel value of the referenced knowledge base image, the first identifier is a first numerical value to indicate that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image.

Taking the decoding flow shown in table 1-1 as an example, during encoding, according to whether the current image to be processed refers to a knowledge base image, determining a value of reference _ to _ library _ picture _ flag (corresponding to the fourth identifier), and encoding the reference _ to _ library _ picture _ flag into a code stream; when the current image to be processed refers to the knowledge base image, judging whether the reconstructed pixel value of the current image to be processed can copy the pixel value of the knowledge base image which is referred to by the current image to be processed according to the fact that whether the pixel value of the current image to be processed is the same or is substantially close to the same, determining the value of copy _ rec _ library _ picture _ flag (corresponding to a first identifier), and encoding the copy _ rec _ library _ picture _ flag into a code stream; when the reconstructed pixel value of the current image to be processed can copy the pixel value of the knowledge base image which is referred to by the current image to be processed, determining the value of copied _ texture _ picture _ idx _ in _ rcs (corresponding to a second identifier) according to the index number of the copied knowledge image in rcs, coding the copied _ texture _ picture _ idx _ in _ rcs into a code stream, skipping the coding process (such as block division, motion compensation, merge, quantization and the like) of the current image to be processed, and not coding all subsequent syntax elements related to the coding process in the code stream. When the reconstructed pixel value of the current image to be processed cannot directly copy the pixel value of the knowledge base image referred by the current image to be processed, an encoding process (such as block division, motion compensation, merge, quantization and the like) is performed on the current image to be processed based on the knowledge base image referred by the current image to be processed, and syntax elements related to the encoding process are coded in the code stream.

Illustratively, in the code stream, the first identifier is located after the fourth identifier.

In another example, the encoding information further includes a fifth identifier and a reference image configuration set, where the fifth identifier is a sequence-level syntax element, the fifth identifier indicates whether inter-frame prediction is performed on a video sequence in which a current image to be processed refers to a knowledge base image, and when the fifth identifier indicates that inter-frame prediction is performed on the video sequence in which the current image to be processed refers to the knowledge base image, the encoding information further includes the reference image configuration set, and the reference image configuration set is used to indicate whether inter-frame prediction is performed on the current image to be processed refers to the knowledge base image.

Specifically, the coding information includes a fifth identifier, when the fifth identifier indicates that inter-frame prediction is performed on a video sequence in which a current image to be processed is located with reference to a knowledge base image, the coding information further includes a reference image configuration set, and when the reference image configuration set indicates that inter-frame prediction is performed on the current image to be processed with reference to the knowledge base image, the coding information further includes the first identifier. Illustratively, the first identifier is located after the reference image configuration set in the code stream, and the reference image configuration set is located after the fifth identifier.

This example corresponds to the coding scheme corresponding to the decoding scheme of the second scheme.

Taking the decoding flows shown in tables 1-2 and 1-3 as examples, during encoding, determining a value of a texture _ picture _ enable _ flag (corresponding to a fifth identifier) according to whether a video sequence of a current image to be processed refers to a knowledge base image, and encoding the texture _ picture _ enable _ flag into a code stream, and when the video sequence of the current image to be processed refers to the knowledge base image, further determining a value of ReferenceTo L ibraryPictureFlag according to whether the current image to be processed refers to the knowledge base image, and performing the following operations:

when the ReferenceTo L ibraricpictureflag value is 1, that is, the current to-be-processed image refers to a knowledge base image, it is determined whether the reconstructed pixel value of the current to-be-processed image can copy the reconstructed pixel value of the knowledge base image to which it refers, according to whether the pixel value of the current to-be-processed image is the same as or substantially close to the same as the pixel value of the knowledge base image to which it refers, the value of copy _ rec _ library _ picture _ flag (corresponding to a first flag) is determined, and the copy _ rec _ library _ picture _ flag is encoded into the code stream.

In yet another example, the encoding information further includes a reference picture configuration set, where the reference picture configuration set is used to indicate whether inter-prediction is performed on the current picture to be processed with reference to a knowledge base picture. Specifically, when the reference image configuration set indicates that inter-frame prediction is performed on the current image to be processed with reference to the knowledge base image, the coding information further includes a first identifier. Illustratively, the first identifier is located after the reference picture configuration set in the codestream.

This example corresponds to the coding method corresponding to the decoding method of the third method.

Taking the decoding flow shown in tables 1-3 as an example, during encoding, the ReferenceTo L ibracryppicteflag value is determined according to whether the current image to be processed refers to the knowledge base image, and the following operations are performed:

In yet another example, the encoding information further includes a fifth flag, and when the fifth flag indicates whether inter prediction on a video sequence in which the current image to be processed is located refers to a knowledge base image. The fifth identification is a sequence level syntax element. Specifically, when the fifth identifier indicates that the current image to be processed is inter-frame predicted with reference to the knowledge base image, the encoding information further includes the first identifier. Illustratively, the first identifier is located after the fifth identifier in the codestream.

This example corresponds to the coding scheme corresponding to the decoding scheme of the fourth scheme.

Taking the decoding flow shown in tables 1-5 as an example, during encoding, according to whether the video sequence of the current image to be processed refers to a knowledge base image, determining the value of a texture _ picture _ enable _ flag (corresponding to the fifth identifier), and encoding the texture _ picture _ enable _ flag into a code stream; when a video sequence where a current image to be processed is located refers to a knowledge base image, judging whether a reconstructed pixel value of the current image to be processed can copy a reconstructed pixel value of a knowledge base image which is referred to by the current image to be processed according to whether the pixel value of the current image to be processed is the same or substantially close to the same, determining a value of copy _ rec _ library _ picture _ flag (corresponding to a first identifier), and encoding the copy _ rec _ library _ picture _ flag into a code stream. When the reconstructed pixel value of the current image to be processed can copy the pixel value of the knowledge base image which is referred to by the current image to be processed, determining the value of copied _ texture _ picture _ idx _ in _ rcs (corresponding to a second identifier) according to the index number of the copied knowledge image in rcs, coding the copied _ texture _ picture _ idx _ in _ rcs into a code stream, skipping the coding process (such as block division, motion compensation, merge, quantization and the like) of the current image to be processed, and not coding all subsequent syntax elements related to the coding process of the current image to be processed in the code stream. When the reconstructed pixel value of the current image to be processed cannot directly copy the pixel value of the knowledge base image referred by the current image to be processed, an encoding process (such as block division, motion compensation, merge, quantization and the like) is performed on the current image to be processed based on the knowledge base image referred by the current image to be processed, and syntax elements related to the encoding process of the current image to be processed are coded in the code stream.

A second method for decoding a video image in an application scenario is described with reference to fig. 10.

In the embodiment of the present application, only one knowledge base image that can be referred to by the current image to be processed may exist, in other words, only one available knowledge image may exist in the external knowledge base at any time. In this case, S1001a, when it is determined that inter prediction is performed on the current image to be processed with reference to the knowledge base image, parses the first flag from the codestream. S1002 or S1005 is executed.

In this embodiment, the meaning of the first identifier is the same as that in the embodiment shown in fig. 7, and reference may be made to the description of the embodiment shown in fig. 7 for the first identifier, which is not described herein again.

S1002, when the first identification indicates that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image, acquiring the pixel value of the knowledge base image referred by the current image to be processed. S1004 is executed.

Certainly, multiple knowledge base images which can be referred to by the current image to be processed may also exist in the knowledge base, in this case, the method performs 1001b, and when it is determined that inter-frame prediction is performed on the current image to be processed to refer to a knowledge base image, parses a third identifier from the code stream, where the third identifier is used to indicate a knowledge base image referred to by the current image to be processed. S1003 is executed.

It is to be understood that S1001a and S1001b are examples of two different cases when there are one or more knowledge base images in the knowledge base to which the current image to be processed can refer, respectively.

And S1003, acquiring the pixel value of the knowledge base image indicated by the third identifier. S1004 is executed. For example, the second identifier may be an index of the knowledge base image to which the current image to be processed refers.

Illustratively, the third flag may be represented by a syntax element texture _ picture _ id in standard text or code.

S1004, see S704, is not described herein again.

S1005, see S705, which is not described herein again.

In the mode 1, similar to the first mode, a fourth identifier is parsed from the code stream, where the fourth identifier is a syntax element of an image level, and the fourth identifier indicates whether inter-frame prediction is performed on a current image to be processed with reference to a knowledge base image.

And in the mode 2, a sixth identifier is analyzed from the code stream, the sixth identifier is a sequence level syntax element, the sixth identifier indicates whether inter-frame prediction is performed on the video sequence where the current image to be processed refers to the knowledge base image, when the sixth identifier indicates that inter-frame prediction is performed on the video sequence where the current image to be processed refers to the knowledge base image, a seventh identifier is analyzed from the code stream, and the seventh identifier is used for indicating whether inter-frame prediction is performed on the current image to be processed refers to the knowledge base image.

For example, the sixth flag in the standard text or code may be represented by a syntax element texture _ picture _ enable _ flag, for example, when texture _ picture _ enable _ flag is 1, it indicates that inter-prediction is performed on the video sequence where the current picture to be processed is located, and when texture _ picture _ enable _ flag is 0, it indicates that inter-prediction is performed on the video sequence where the current picture to be processed is located, and does not refer to the knowledge base picture.

Illustratively, the seventh flag in the standard text or code may be represented by a syntax element texture _ picture _ enable _ flag, for example, when reference _ to _ texture _ picture _ flag is 1, it indicates that the current picture to be processed is inter-predicted to refer to the knowledge base picture, and when reference _ to _ texture _ picture _ flag is 0, it indicates that the current picture to be processed is inter-predicted to refer to no knowledge base picture.

Mode 3, whether the current image to be processed is subjected to inter-frame prediction to refer to a knowledge base image is determined based on the reference image configuration set.

In HEVC or VVC, the reference picture configuration set may be represented by rps.

As an example, the present example describes a part of syntax elements of a video image decoding method when determining whether inter prediction is performed on a current image to be processed with reference to a knowledge base image in a manner 1, see table 2-1, so that only one knowledge base image available for encoding the current image to be processed exists in the knowledge base at any time.

TABLE 2-1

In table 2-1, reference _ to _ library _ picture _ flag corresponds to the fourth flag. copy _ rec _ library _ picture _ flag corresponds to the first flag.

The method includes parsing reference _ to _ texture _ picture _ flag (for example, 1-bit flag, which may be carried in a slice header) from a code stream, when reference _ to _ texture _ picture _ flag is 1, indicating that an inter prediction reference knowledge base picture is performed on a current picture to be processed, parsing copy _ rec _ texture _ picture _ flag (for example, 1-bit flag) from the code stream, when copy _ rec _ texture _ picture _ flag is 1, indicating that a reconstructed pixel value of the current picture is not obtained by using a prediction compensation-based method, and may directly copy a pixel value of a reference knowledge picture, when copy _ texture _ picture _ flag is 0, indicating that a reconstructed pixel value of the current picture is not directly copied to a reconstructed pixel value of a knowledge picture to be referred to, when a current picture to be processed does not include a value of a reference texture _ flag, obtaining a reconstructed pixel value of the current picture to be processed by using a motion compensation mode, and when a subsequent motion compensation element flag is set as flag 350, and when the current picture to be processed by a motion compensation element, and the current picture to be processed as a current picture to be processed by a motion compensation element, and a current picture to be processed by a current picture _ texture _.

Note that, when explicit transmission of copy _ rec _ library _ picture _ flag is adopted, in the embodiment of the present application, the element of copy rec L ibrarypicture flag may not be configured, and if (copy rec L ibrarypicture flag ═ 0) in table 2-1 may be represented by if (copy _ rec _ library _ picture _ flag ═ 0).

For example, the structure of the partial syntax elements in the bitstream in table 2-1 can be seen in fig. 11A, copy _ rec _ library _ picture _ flag and Reference to L ibrarypicture flag are in the slice header, L one _ term _ Reference in fig. 11A indicates long-term Reference.

As another example, the present example describes a part of syntax elements of a video image decoding method when determining whether inter prediction is performed on a current image to be processed with reference to a knowledge base image in a manner 2, see table 2-2, so that only one knowledge base image available for encoding the current image to be processed exists in the knowledge base at any time.

Tables 2 to 2

In table 2-2, the texture _ picture _ enable _ flag corresponds to the sixth flag, and the reference _ to _ texture _ picture _ flag corresponds to the seventh flag. copy _ rec _ library _ picture _ flag corresponds to the first flag.

When the parameter.

For example, the structure of part of the syntax elements in table 2-2 above in the bitstream can be seen in fig. 11B. copy _ rec _ feature _ picture _ flag and reference _ to _ feature _ picture _ flag are in the slice header and feature _ picture _ enable _ flag is in the sequence header.

As still another example, the present example describes a part of syntax elements of a video image decoding method when determining whether inter prediction is performed on a current image to be processed with reference to a knowledge base image in manner 2, see table 2-3, taking as an example that there are multiple knowledge base images available in the knowledge base when encoding is performed on the current image to be processed. When only one knowledge base image available for encoding the current image to be processed exists in the knowledge base at any moment, the library _ picture _ id does not need to be analyzed in tables 2 to 3.

Tables 2 to 3

In tables 2-3, the texture _ picture _ enable _ flag corresponds to the sixth flag, and the reference _ to _ texture _ picture _ flag corresponds to the seventh flag. copy _ rec _ feature _ picture _ flag corresponds to the first flag, and feature _ picture _ id corresponds to the third flag.

When the video sequence in which the current picture to be processed is located is parsed from a sequence header of a bitstream, and when the video sequence in which the current picture to be processed is located is parsed, the video sequence in which the current picture to be processed is located is indicated to refer to a knowledge base image for inter-frame prediction, a reference _ to _ feature _ picture _ flag (for example, a 1-bit flag, which may be carried in a slice header) is parsed from the bitstream, and when the reference _ to _ feature _ picture _ flag is equal to 1, the video sequence in which the current picture to be processed is indicated to refer to a knowledge base image for inter-frame prediction, and a copy _ recovery _ feature _ picture _ flag (for example, a 1-bit flag) and a feature _ picture _ id are parsed from the bitstream. The copy _ rec _ texture _ picture _ flag is 1, which means that the reconstructed pixel value of the current image is not obtained by using a method based on prediction compensation, and the pixel value of the knowledge image referred to by the copy _ rec _ texture _ flag may be directly copied, specifically, the pixel value of the knowledge base image indicated by the texture _ id may be copied to determine the reconstructed pixel value of the current image to be processed. And when the copy _ rec _ texture _ picture _ flag is 0, the reconstructed pixel value of the knowledge image which is referred to by the copy _ rec _ texture _ picture _ flag is not directly copied, and the reconstructed pixel value of the current image to be processed can be obtained by referring to the knowledge base image indicated by the texture _ id in a motion compensation mode.

When copy _ rec _ texture _ picture _ flag is equal to 1, the copy rec L ibrarypicture flag is assigned to 1, at this time, a syntax element related to motion compensation of a subsequent image to be processed is not included in the code stream, and when the value of copy _ rec _ texture _ picture _ flag is 0 or does not exist, the copy rec L ibrarypicture flag is assigned to 0, and at this time, a syntax element related to motion compensation of a subsequent image to be processed is included in the code stream.

For example, the structure of some syntax elements in the bitstream in tables 2-3 above can be seen from fig. 11C, copy _ rec _ texture _ picture _ flag and reference _ to _ texture _ picture _ flag, texture _ picture _ id are in the slice header, texture _ picture _ enable _ flag is in the sequence header, L texture _ reference includes information indicating the knowledge base picture carrying the current picture reference to be processed, such as the number of reference knowledge base pictures, the index or id of the knowledge base picture, and so on.

As still another example, the present example describes a part of syntax elements of a video image decoding method when determining whether inter prediction is performed on a current image to be processed with reference to a knowledge base image in manner 3, see tables 2 to 4, taking the case where there are a plurality of knowledge base images available in the knowledge base for encoding the current image to be processed as an example.

Tables 2 to 4

In tables 2-4, copy _ rec _ library _ picture _ flag corresponds to the first flag.

The method includes the steps of obtaining a reference picture configuration set (rps) used by a current picture to be processed, deriving a reference picture flag value according to information of the rps used by the current picture to be processed, for example, when the reference picture in the rps used by the current picture to be processed is a knowledge base picture, the reference picture flag value L of the current picture to be processed is 1, when the reference picture in the rps used by the current picture to be processed is an unknown base picture, the reference picture flag value L of the current picture to be processed is 0, the reference picture flag value L of the current picture to be processed is 1, which indicates that the current picture to be processed is subjected to inter-prediction reference knowledge base picture, and at this time, a reconstruction method for reconstructing the current picture based on a reconstructed reference picture flag 1 may be performed by analyzing the reference picture _ flag _ 1, which indicates that the current picture to be reconstructed can be directly obtained based on a reconstructed reference picture and a reconstructed reference picture-flag _ 1, and a reconstructed reference picture to be reconstructed by a reconstruction method which is not directly performed on the current picture to be processed.

For example, the structure of part of the syntax elements in tables 2-4 above in the bitstream can be seen in fig. 11D. copy _ rec _ texture _ picture _ flag, texture _ picture _ id are in the slice header.

The following describes a video image encoding method in a second application scenario. Illustratively, referring to fig. 12, only step S1202 may be included. Optionally, S1201 and S1202 may also be included.

And S1201, determining the coding information of the current image block to be processed.

S1202, coding the coding information into a code stream; the coding information is used for providing reference information and a using method of the reference information for a decoding end so as to recover a reconstructed pixel value of the current image to be processed; when the current image to be processed is determined to be inter-frame predicted to refer to the knowledge base image, the coding information comprises a first identifier, and the first identifier is used for indicating whether the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image.

When the pixel value of the current image to be processed is the same or substantially close to the same as the pixel value of the referenced knowledge base image, the first identifier is a first numerical value to indicate that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image.

Illustratively, when the pixel value of the current image to be processed is the same or substantially close to the same as the pixel value of the referenced knowledge base image, a third identifier for indicating the knowledge base image referenced by the current image to be processed is further included in the encoded information; wherein the pixel value of the knowledge base image indicated by the third identifier is used for determining a reconstructed pixel value of the current image to be processed.

Illustratively, in the code stream, the third identifier is not in sequence with the first identifier.

Illustratively, when the first flag is a second value, the first flag is used to indicate that the reconstructed pixel value of the current to-be-processed image does not copy the pixel value of the knowledge base image. Correspondingly, when the first identifier is the second numerical value, the encoded information may further include another identifier for indicating that the reconstructed pixel value of the current image to be processed is determined by a non-copy method. Illustratively, the second value may be 0. When the copy _ rec _ texture _ picture _ flag value is 0, syntax elements related to motion compensation of the current image to be processed need to be coded into the code stream at this time.

This example corresponds to the encoding method corresponding to the decoding method of the above-described method 1.

Taking the decoding flow shown in table 2-1 as an example, correspondingly, during encoding, determining a value of reference _ to _ library _ picture _ flag (corresponding to the fourth identifier) according to whether the current image to be processed refers to the knowledge base image, and encoding the reference _ to _ library _ picture _ flag into the code stream; when the current image to be processed refers to the knowledge base image, judging whether the reconstructed pixel value of the current image to be processed can copy the pixel value of the knowledge base image which is referred to by the current image to be processed according to the fact that whether the pixel value of the current image to be processed is the same or is substantially close to the same, determining the value of copy _ rec _ library _ picture _ flag (corresponding to a first identifier), and encoding the copy _ rec _ library _ picture _ flag into a code stream; when the reconstructed pixel value of the current image to be processed can directly copy the pixel value of the knowledge base image which is referred to by the current image to be processed, the encoding process (such as block division, motion compensation, merge, quantization and the like) of the current image to be processed is skipped, and all subsequent syntax elements related to the encoding method are not coded in the code stream. When the reconstructed pixel value of the current image to be processed cannot directly copy the pixel value of the knowledge base image referred by the current image to be processed, an encoding process (such as a traditional encoding process including block division, motion compensation, merge, quantization and the like) is performed on the current image to be processed based on the knowledge base image referred by the current image to be processed, and syntax elements related to the encoding process of the current image to be processed are coded in the code stream.

In another example, the encoding information further includes a reference picture configuration set, where the reference picture configuration set is used to indicate whether inter-prediction is performed on the current picture to be processed with reference to a knowledge base picture. Specifically, when the reference image configuration set indicates that inter-frame prediction is performed on the current image to be processed with reference to the knowledge base image, the coding information further includes a first identifier. Illustratively, the first identifier is located after the reference picture configuration set in the codestream.

This example corresponds to the encoding method corresponding to the decoding method of the above-described method 3.

Taking the decoding flow shown in tables 2-4 as an example, during encoding, the ReferenceTo L ibracryppicteflag value is determined according to whether the current to-be-processed image refers to the knowledge base image, and the following operations are performed:

when the ReferenceTo L ibrarypicture flag value is 1, that is, the current to-be-processed picture refers to a knowledge base picture, it is determined whether the reconstructed pixel value of the current to-be-processed picture can copy the reconstructed pixel value of the knowledge base picture to which it refers, according to whether the pixel value of the current to-be-processed picture is the same as or substantially close to the same as the pixel value of the knowledge base picture to which it refers, the value of copy _ rec _ library _ picture _ flag (corresponding to a first flag) is determined, and the copy _ rec _ library _ picture _ flag is encoded into the code stream.

In yet another example, the encoding information further includes a sixth flag, and when the sixth flag indicates whether inter prediction on a video sequence in which the current image to be processed is located refers to a knowledge base image. Specifically, when the sixth identifier indicates that the current image to be processed is inter-frame predicted with reference to the knowledge base image, the encoding information further includes a seventh identifier, where the seventh identifier is used to indicate whether the current image to be processed refers to the knowledge base image. When the seventh mark indicates that the current image to be processed refers to the knowledge base image, the first mark is further included in the coding information. Illustratively, the first identifier is located after the seventh identifier in the code stream, and the seventh identifier is located after the sixth identifier.

This example corresponds to the encoding method corresponding to the decoding method of the above-described method 2.

Taking the decoding flow shown in table 2-2 as an example, correspondingly, during encoding, according to the value of the library _ picture _ enable _ flag (sixth flag) in the sequence header, it is determined whether the video sequence in which the current image to be processed is located refers to the knowledge base image; when the video sequence where the current image to be processed is located refers to the knowledge base image, determining the value of reference _ to _ library _ picture _ flag (corresponding to the seventh identifier) according to whether the current image to be processed refers to the knowledge base image, and encoding the reference _ to _ library _ picture _ flag into a code stream; when the current image to be processed refers to the knowledge base image, judging whether the reconstructed pixel value of the current image to be processed can copy the pixel value of the knowledge base image which is referred to by the current image to be processed according to the fact that whether the pixel value of the current image to be processed is the same or is substantially close to the same, determining the value of copy _ rec _ library _ picture _ flag (corresponding to a first identifier), and encoding the copy _ rec _ library _ picture _ flag into a code stream; when the reconstructed pixel value of the current image to be processed can directly copy the pixel value of the knowledge base image which is referred to by the reconstructed pixel value, the encoding process (such as block division, motion compensation, merge, quantization and the like) of the current image to be processed is skipped, and all subsequent syntax elements related to the encoding process of the current image to be processed are not coded in the code stream. When the reconstructed pixel value of the current image to be processed cannot directly copy the pixel value of the knowledge base image referred by the current image to be processed, and an encoding process (for example, a conventional encoding process, such as block division, motion compensation, merge, quantization, and the like) is performed on the current image to be processed based on the knowledge base image referred by the current image to be processed, and syntax elements related to the encoding process of the current image to be processed are encoded into the code stream.

Based on the same inventive concept as the above method, as shown in fig. 13, an embodiment of the present application further provides a video image decoding apparatus 1300, where the apparatus 1300 includes an image storage unit 1301 and an decapsulation unit 1302. The apparatus 1300 may further include a decoding unit 1303.

The image storage unit 1301 is used for storing a knowledge base image;

the decapsulation unit 1302 is configured to, when determining to perform inter-frame prediction on a current image to be processed with reference to a knowledge base image, parse the first identifier from the code stream; when the first identifier indicates that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image, acquiring the pixel value of the knowledge base image referred to by the current image to be processed from the image storage unit 1301; and determining a reconstruction pixel value of the current image to be processed according to the acquired pixel value of the knowledge base image.

Illustratively, the decapsulation unit 1302 is further configured to, when the first identifier indicates that a reconstructed pixel value of the current image to be processed copies a pixel value of a knowledge base image, parse a second identifier from the code stream, where the second identifier is used to indicate a knowledge base image referred to by the current image to be processed; the decapsulation unit 1302 is specifically configured to, in terms of obtaining the pixel value of the knowledge base image referred to by the current image to be processed, obtain the pixel value of the knowledge base image indicated by the second identifier from the image storage unit 1301.

Illustratively, the decapsulation unit 1302 is further configured to, when it is determined that inter-frame prediction is performed on a current image to be processed to refer to a knowledge base image, parse a third identifier from the code stream, where the third identifier is used to indicate the knowledge base image referred to by the current image to be processed; the decapsulation unit 1302 is specifically configured to, in terms of obtaining the pixel value of the knowledge base image referred to by the current image to be processed, obtain the pixel value of the knowledge base image indicated by the third identifier from the image storage unit 1301.

Illustratively, the decapsulation unit 1302 is further configured to determine whether inter prediction performed on the current image to be processed refers to a knowledge base image by any one of:

alternatively, the first and second electrodes may be,

analyzing a fifth identification from a code stream, wherein the fifth identification is a sequence level syntax element, the fifth identification indicates whether inter-frame prediction is performed on a video sequence in which a current image to be processed refers to a knowledge base image, and when the fifth identification indicates that inter-frame prediction is performed on the video sequence in which the current image to be processed refers to the knowledge base image, determining whether inter-frame prediction is performed on the current image to be processed refers to the knowledge base image based on a reference image configuration set analyzed from the code stream;

alternatively, the first and second electrodes may be,

and resolving a sixth identification from the code stream, and resolving a seventh identification from the code stream when the sixth identification indicates that the current to-be-processed image is subjected to inter-frame prediction on a video sequence in which the current to-be-processed image is positioned and refers to a knowledge base image, wherein the seventh identification indicates whether the current to-be-processed image is subjected to inter-frame prediction or not to refer to the knowledge base image.

In one possible design, the decapsulating unit 1302 is further configured to, when the first identifier indicates that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image, obtain, by the decoding unit 1303, the reconstructed pixel value of the current image to be processed in a non-copy manner by using the knowledge base image referred to by the current image (e.g., perform a conventional decoding process on the current image to be processed based on the knowledge base image referred to by the current image to be processed).

Illustratively, the first identifier is carried in a slice header, a picture header, or a sequence header.

For example, in terms of determining a reconstructed pixel value of the current image to be processed based on the obtained pixel value of the knowledge base image, the decapsulation unit 1302 is specifically configured to use the obtained pixel value of the knowledge base image as the reconstructed pixel value of the current image to be processed.

It should be further noted that, for the specific implementation process of the image storage unit 1301, the decapsulation unit 1302, and the decoding unit 1303, reference may be made to the detailed description of the embodiment in fig. 7 or fig. 10, and for brevity of the description, no further description is given here.

Exemplarily, at a decoding end, in fig. 13, a position of the image storage unit 1301 corresponds to a position of the DPB330 in fig. 3, in other words, a specific implementation of a function of the image storage unit 1301 can refer to specific details of the DPB330 in fig. 3. The location of the decapsulation unit 1302 corresponds to the location of the decapsulation unit 303 in fig. 3, in other words, the specific implementation of the function of the decapsulation unit 1302 and the specific details of the decapsulation unit 303 in fig. 3 can be referred to each other. The decoding unit 1303 here may correspond to a combination of one or more of the entropy decoding unit 303, the prediction processing unit 360, and the reconstruction unit 314 in the decoder in fig. 3.

Based on the same inventive concept as the above method, as shown in fig. 14, the embodiment of the present application further provides a video image encoding apparatus 1400, where the apparatus 1400 includes an image storage unit 1401 and a bitstream packing unit 1402.

An image storage unit 1401 for storing a knowledge base image;

a code stream packaging unit 1402 for encoding the coding information into a code stream;

when it is determined that the current image to be processed is subjected to inter-frame prediction and refers to a knowledge base image, the coding information comprises a first identifier, and the first identifier is used for indicating whether a reconstructed pixel value of the current image to be processed copies a pixel value of the knowledge base image; when the first identifier is a first numerical value, the first identifier is used for indicating the pixel value of the reconstructed pixel value copy knowledge base image of the current image to be processed.

Illustratively, in the code stream, the second identifier is located after the first identifier.

Illustratively, when it is determined that the current image to be processed refers to a knowledge base image for inter-frame prediction, the encoding information further includes a third identifier, where the third identifier is used to indicate the knowledge base image referred to by the current image to be processed; wherein the pixel value of the knowledge base image indicated by the third identifier is used for determining a reconstructed pixel value of the current image to be processed.

Illustratively, when the first flag is a second value, the first flag is used to indicate that the reconstructed pixel value of the current to-be-processed image does not copy the pixel value of the knowledge base image. Correspondingly, the encoding information further includes other identifiers for indicating that the reconstructed pixel value of the current image to be processed is determined by a non-copy method, which is described in detail in the foregoing embodiments and is not described herein again.

Illustratively, the encoding information further includes a fourth flag, where the fourth flag is a syntax element of an image level, and the fourth flag is used to indicate whether inter-prediction is performed on the current image to be processed with reference to a knowledge base image.

Illustratively, the encoding information further includes a fifth identifier and a reference image configuration set, where the fifth identifier is a sequence level syntax element, the fifth identifier indicates whether inter-frame prediction is performed on a video sequence in which the current image to be processed refers to a knowledge base image, and when the fifth identifier indicates that inter-frame prediction is performed on the video sequence in which the current image to be processed refers to the knowledge base image, the reference image configuration set is used to indicate whether inter-frame prediction is performed on the current image to be processed refers to the knowledge base image.

Illustratively, the encoding information further includes a reference image configuration set, where the reference image configuration set is used to indicate whether inter-prediction is performed on the current image to be processed with reference to a knowledge base image.

Illustratively, the encoding information further includes a sixth identifier, where the sixth identifier is a syntax element of a sequence level, the sixth identifier indicates whether inter-prediction is performed on a video sequence in which the current image to be processed refers to a knowledge base image, and when the sixth identifier indicates that inter-prediction is performed on the video sequence in which the current image to be processed refers to the knowledge base image, the encoding information further includes a seventh identifier, where the seventh identifier is a syntax element of a picture level, and the seventh identifier is used to indicate whether inter-prediction is performed on the current image to be processed refers to the knowledge base image.

It should be further noted that, for the specific implementation process of the image storage unit 1401 and the code stream encapsulation unit 1402, reference may be made to the detailed description of the embodiment in fig. 9 or fig. 12, and for brevity of description, no further description is given here. Exemplarily, at the encoding end, in fig. 14, the position of the image storage unit 1401 corresponds to the position of the DPB230 in fig. 2, in other words, the specific implementation of the function of the image storage unit 1401 may refer to the specific details of the DPB230 in fig. 2. The position of the code stream packaging unit 1402 corresponds to the position of the code stream packaging unit 280 in fig. 2, in other words, the specific implementation of the function of the code stream packaging unit 1402 and the specific details referring to the code stream packaging unit 280 in fig. 2 can be referred to each other.

Those of skill in the art will appreciate that the functions described in connection with the various illustrative logical blocks, modules, and algorithm steps described in the disclosure herein may be implemented as hardware, software, firmware, or any combination thereof. If implemented in software, the functions described in the various illustrative logical blocks, modules, and steps may be stored on or transmitted over as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. The computer-readable medium may include a computer-readable storage medium, which corresponds to a tangible medium, such as a data storage medium, or any communication medium including a medium that facilitates transfer of a computer program from one place to another (e.g., according to a communication protocol). In this manner, a computer-readable medium may generally correspond to (1) a non-transitory tangible computer-readable storage medium, or (2) a communication medium, such as a signal or carrier wave. A data storage medium may be any available medium that can be accessed by one or more computers or one or more processors to retrieve instructions, code and/or data structures for implementing the techniques described herein. The computer program product may include a computer-readable medium.

By way of example, and not limitation, such computer-readable storage media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer.

The instructions may be executed by one or more processors, such as one or more Digital Signal Processors (DSPs), general purpose microprocessors, Application Specific Integrated Circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Thus, the term "processor," as used herein may refer to any of the foregoing structure or any other structure suitable for implementation of the techniques described herein. Additionally, in some aspects, the functions described by the various illustrative logical blocks, modules, and steps described herein may be provided within dedicated hardware and/or software modules configured for encoding and decoding, or incorporated in a combined codec. Also, the techniques may be fully implemented in one or more circuits or logic elements.

The techniques of this application may be implemented in a wide variety of devices or apparatuses, including a wireless handset, an Integrated Circuit (IC), or a set of ICs (e.g., a chipset). Various components, modules, or units are described in this application to emphasize functional aspects of means for performing the disclosed techniques, but do not necessarily require realization by different hardware units. Indeed, as described above, the various units may be combined in a codec hardware unit, in conjunction with suitable software and/or firmware, or provided by an interoperating hardware unit (including one or more processors as described above).

In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

The above description is only an exemplary embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method for decoding video images, comprising:

when the current image to be processed is determined to be subjected to inter-frame prediction and reference to the knowledge base image, analyzing a first identifier from a code stream;

when the first identification indicates that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image, acquiring the pixel value of the knowledge base image referred by the current image to be processed;

and determining a reconstruction pixel value of the current image to be processed according to the acquired pixel value of the knowledge base image.

2. The method of claim 1, further comprising:

when the first identification indicates that the reconstructed pixel value of the current image to be processed copies the pixel value of the knowledge base image, a second identification is analyzed from the code stream, and the second identification is used for indicating the knowledge base image referred by the current image to be processed;

the acquiring the pixel value of the knowledge base image referred by the current image to be processed comprises:

and acquiring the pixel value of the knowledge base image indicated by the second identification.

3. The method of claim 1, further comprising:

when the current image to be processed is determined to be inter-frame predicted and referred to a knowledge base image, analyzing a third identifier from the code stream, wherein the third identifier is used for indicating the knowledge base image referred to by the current image to be processed;

acquiring a pixel value of a knowledge base image referred by the current image to be processed, wherein the pixel value comprises the following steps:

and acquiring the pixel value of the knowledge base image indicated by the third identification.

4. A method according to any one of claims 1 to 3, wherein it is determined whether inter-prediction of the current picture to be processed refers to a knowledge base picture by any one of:

alternatively, the first and second electrodes may be,

analyzing a fifth identifier from the code stream, wherein the fifth identifier is a sequence level syntax element and indicates whether inter-frame prediction is performed on a video sequence in which a current image to be processed refers to a knowledge base image or not; when the fifth identification indicates that inter-frame prediction is carried out on the current video sequence where the image to be processed is located to refer to the knowledge base image, whether inter-frame prediction is carried out on the current image to be processed to refer to the knowledge base image or not is determined based on a reference image configuration set analyzed from the code stream;

alternatively, the first and second electrodes may be,

5. The method of any one of claims 1-4, further comprising:

when the first identification indicates that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image, the reconstructed pixel value of the current image to be processed is obtained in a non-copy mode by using the knowledge base image.

6. The method of any of claims 1-5, wherein the first identifier is carried in a slice header, a picture header, or a sequence header.

7. The method of any one of claims 1-6, wherein determining the reconstructed pixel value of the current image to be processed based on the pixel values of the acquired knowledge base images comprises:

and taking the pixel value of the acquired knowledge base image as a reconstruction pixel value of the current image to be processed.

8. A video image encoding method, comprising:

coding the coding information into a code stream;

9. The method of claim 8, wherein when the first identifier is a first numerical value, a second identifier is further included in the encoded information, and the second identifier is used for indicating a knowledge base image to which the current image to be processed refers; wherein the pixel value of the knowledge base image indicated by the second identifier is used for determining a reconstructed pixel value of the current image to be processed.

10. The method of claim 9, wherein the second marker is located after the first marker in the codestream.

11. The method according to claim 8, wherein when it is determined that the current image to be processed refers to a knowledge base image for inter-prediction, the encoding information further includes a third flag indicating a knowledge base image to which the current image to be processed refers; wherein the pixel value of the knowledge base image indicated by the third identifier is used for determining a reconstructed pixel value of the current image to be processed.

12. The method of any of claims 8-11, wherein when the first identifier is a second value,

the first mark is used for indicating that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image.

13. The method according to any of claims 8-12, wherein a fourth flag is further included in the coding information, the fourth flag is a syntax element of a picture level, and the fourth flag is used for indicating whether inter prediction on the current picture to be processed refers to a knowledge base picture.

14. The method according to any one of claims 8 to 12, wherein the coding information further includes a fifth flag and a reference picture configuration set, the fifth flag is a syntax element of a sequence hierarchy, the fifth flag indicates whether inter-prediction is performed on a video sequence in which the current picture to be processed refers to a knowledge base picture, and when the fifth flag indicates that inter-prediction is performed on the video sequence in which the current picture to be processed refers to the knowledge base picture, the reference picture configuration set is used to indicate whether inter-prediction is performed on the current picture to be processed refers to the knowledge base picture.

15. The method according to any one of claims 8-12, wherein the coding information further comprises a reference picture configuration set indicating whether inter prediction of the current picture to be processed refers to a knowledge base picture.

16. The method according to any one of claims 8 to 12, wherein a sixth flag is further included in the coding information, the sixth flag is a syntax element of a sequence level, the sixth flag indicates whether inter-prediction is performed on the video sequence in which the current picture to be processed refers to a knowledge base picture, and when the sixth flag indicates that inter-prediction is performed on the video sequence in which the current picture to be processed refers to a knowledge base picture, the coding information further includes a seventh flag, the seventh flag is a syntax element of a picture level, and the seventh flag is used to indicate whether inter-prediction is performed on the current picture to be processed refers to a knowledge base picture.

17. The method of any of claims 8-16, wherein the first identifier is carried in a slice header, a picture header, or a sequence header.

18. A video image decoding apparatus, comprising:

an image storage unit for storing a knowledge base image;

19. The apparatus of claim 18, wherein the decapsulating unit is further configured to parse, from the codestream, a second flag indicating a knowledge base image to which the current to-be-processed image refers, when the first flag indicates that reconstructed pixel values of the current to-be-processed image copy pixel values of the knowledge base image;

the decapsulation unit is specifically configured to, in terms of obtaining the pixel value of the knowledge base image referred to by the current image to be processed, obtain the pixel value of the knowledge base image indicated by the second identifier from the image storage unit.

20. The apparatus of claim 18, wherein the decapsulating unit is further configured to, when it is determined that inter-prediction is performed on a current to-be-processed image with reference to a knowledge base image, parse a third identifier from the code stream, where the third identifier is used to indicate a knowledge base image to which the current to-be-processed image refers;

21. The apparatus according to any of claims 18-20, wherein the decapsulating unit is further configured to determine whether inter prediction for the current picture to be processed refers to a knowledge base picture by any of:

alternatively, the first and second electrodes may be,

22. The apparatus according to any of claims 18-21, wherein the apparatus further comprises a decoding unit,

the decapsulation unit is further configured to, when the first identifier indicates that the reconstructed pixel value of the current image to be processed does not copy the pixel value of the knowledge base image, obtain, by the decoding unit, the reconstructed pixel value of the current image to be processed in a non-copy manner using the knowledge base image.

23. The apparatus of any of claims 18-22, wherein the first identifier is carried in a slice header, a picture header, or a sequence header.

24. The apparatus according to any of claims 18 to 23, wherein the decapsulating unit is specifically configured to, in determining the reconstructed pixel value of the current image to be processed based on the pixel values of the acquired knowledge base image, treat the pixel values of the acquired knowledge base image as the reconstructed pixel value of the current image to be processed.

25. A video image encoding apparatus, comprising:

an image storage unit for storing a knowledge base image;

when it is determined that the current image to be processed is subjected to inter-frame prediction and refers to a knowledge base image, the coding information comprises a first identifier, and the first identifier is used for indicating whether a reconstructed pixel value of the current image to be processed copies a pixel value of the knowledge base image;

26. The apparatus according to claim 25, wherein when the first flag is a first value, a second flag is further included in the encoded information, the second flag indicating a knowledge base image to which the current image to be processed refers; wherein the pixel value of the knowledge base image indicated by the second identifier is used for determining a reconstructed pixel value of the current image to be processed.

27. The apparatus of claim 26, wherein the second marker is located after the first marker in the codestream.

28. The apparatus of claim 25, wherein when it is determined that a current to-be-processed image refers to a knowledge base image for inter-prediction, the encoding information further comprises a third flag indicating a knowledge base image to which the current to-be-processed image refers; wherein the pixel value of the knowledge base image indicated by the third identifier is used for determining a reconstructed pixel value of the current image to be processed.

29. The apparatus of any of claims 25-28, wherein when the first identifier is a second value,

30. The apparatus according to any of claims 25-29, wherein the coding information further comprises a fourth flag, the fourth flag is a syntax element of a picture level, and the fourth flag is used for indicating whether inter prediction on a current picture to be processed refers to a knowledge base picture.

31. The apparatus according to any of claims 25-29, wherein the coding information further includes a fifth flag and a reference picture configuration set, the fifth flag is a syntax element of a sequence hierarchy, the fifth flag indicates whether inter-prediction is performed on the video sequence of the current picture to be processed to refer to a knowledge base picture, and when the fifth flag indicates that inter-prediction is performed on the video sequence of the current picture to be processed to refer to a knowledge base picture, the reference picture configuration set is used to indicate whether inter-prediction is performed on the current picture to be processed to refer to a knowledge base picture.

32. The method according to any of claims 25-29, wherein the coding information further comprises a reference picture configuration set indicating whether inter prediction of the current picture to be processed refers to a knowledge base picture.

33. The method according to any one of claims 25 to 29, wherein a sixth flag is further included in the coding information, the sixth flag is a syntax element of a sequence level, the sixth flag indicates whether inter-prediction is performed on the video sequence in which the current picture to be processed refers to a knowledge base picture, and when the sixth flag indicates that inter-prediction is performed on the video sequence in which the current picture to be processed refers to a knowledge base picture, the coding information further includes a seventh flag, the seventh flag is a syntax element of a picture level, and the seventh flag is used to indicate whether inter-prediction is performed on the current picture to be processed refers to a knowledge base picture.

34. The method of any of claims 25-33, wherein the first identifier is carried in a slice header, a picture header, or a sequence header.

35. A video decoding apparatus, comprising: a non-volatile memory and a processor coupled to each other, the processor calling program code stored in the memory to perform the method as described in any one of claims 1-7.

36. A video encoding device comprising: a non-volatile memory and a processor coupled to each other, the processor calling program code stored in the memory to perform the method as described in any one of claims 8-17.