WO2020119814A1 - 图像重建方法和装置 - Google Patents

图像重建方法和装置 Download PDF

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Publication number
WO2020119814A1
WO2020119814A1 PCT/CN2019/125393 CN2019125393W WO2020119814A1 WO 2020119814 A1 WO2020119814 A1 WO 2020119814A1 CN 2019125393 W CN2019125393 W CN 2019125393W WO 2020119814 A1 WO2020119814 A1 WO 2020119814A1
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prediction
block
current coding
coding unit
mode
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PCT/CN2019/125393
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English (en)
French (fr)
Inventor
赵寅
杨海涛
赵日洋
李忠良
张恋
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华为技术有限公司
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Priority to EP19894750.9A priority Critical patent/EP3890321A4/en
Publication of WO2020119814A1 publication Critical patent/WO2020119814A1/zh
Priority to US17/345,295 priority patent/US11924438B2/en
Priority to US18/430,963 priority patent/US20240205419A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
    • H04N19/119—Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
    • H04N19/103—Selection of coding mode or of prediction mode
    • H04N19/107—Selection of coding mode or of prediction mode between spatial and temporal predictive coding, e.g. picture refresh
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
    • H04N19/12—Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264
    • H04N19/122—Selection of transform size, e.g. 8x8 or 2x4x8 DCT; Selection of sub-band transforms of varying structure or type
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/134—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or criterion affecting or controlling the adaptive coding
    • H04N19/157—Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter
    • H04N19/159—Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
    • H04N19/17—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object
    • H04N19/176—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object the region being a block, e.g. a macroblock
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
    • H04N19/186—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being a colour or a chrominance component

Definitions

  • the present application relates to the technical field of video encoding and decoding, and more specifically, to an image reconstruction method and device.
  • Digital video capabilities can be incorporated into a variety of devices, including digital TVs, digital live broadcast systems, wireless broadcasting systems, personal digital assistants (PDAs), laptop or desktop computers, tablet computers, electronics Book readers, digital cameras, digital recording devices, digital media players, video game devices, video game consoles, cellular or satellite radio phones (so-called "smart phones"), video teleconferencing devices, video streaming devices And the like.
  • Digital video devices implement video compression techniques, for example, in the standards defined by MPEG-2, MPEG-4, ITU-T H.263, ITU-T H.264/MPEG-4 Part 10 Advanced Video Coding (AVC), The video coding standard H.265/high efficiency video coding (HEVC) standard and the video compression technology described in the extension of such standards.
  • Video devices can more efficiently transmit, receive, encode, decode, and/or store digital video information by implementing such video compression techniques.
  • Video compression techniques perform spatial (intra-image) prediction and/or temporal (inter-image) prediction to reduce or remove redundancy inherent in video sequences.
  • a video slice ie, a video frame or a portion of a video frame
  • the image block in the to-be-intra-coded (I) slice of the image is encoded using spatial prediction regarding reference samples in adjacent blocks in the same image.
  • An image block in an inter-coded (P or B) slice of an image may use spatial prediction relative to reference samples in neighboring blocks in the same image or temporal prediction relative to reference samples in other reference images.
  • the image may be referred to as a frame, and the reference image may be referred to as a reference frame.
  • Embodiments of the present application provide a video image encoding and decoding method, device, and corresponding encoder and decoder, which can improve encoding and decoding performance to a certain extent.
  • an embodiment of the present application provides a video decoding method, including:
  • the dividing the luma block of the current coding unit into at least two luma prediction blocks according to the size information of the current coding unit includes:
  • the first division mode is used to divide the luminance block of the current coding unit, X is a positive integer, and the first division mode includes four equal divisions or Asymmetric division; or,
  • the luminance block of the current coding unit is divided using a quadrant division method, and Y is a positive integer; or,
  • a four-part division method is used to perform the luminance block of the current coding unit Division, wherein the division direction of the four-division division mode is perpendicular to the side to be divided of the current coding unit, A and B are positive integers, and the side length of the side to be divided of the current coding unit is at the brightness
  • the width of the current coding unit, the side length of the non-dividing side of the current coding unit is the vertical division of the luminance block Or the height of the current coding unit during vertical asymmetric division; or, the side length of the side to be divided of the current coding unit is when the division mode of the luminance block is horizontal quadrant or horizontal asymmetric division
  • the second coding mode is used to divide the luminance block of the current coding unit,
  • the second division mode does not include quadrant and asymmetric division, the division direction of the second division mode is perpendicular to the to-be-divided side of the current coding unit, and C and D are positive integers; or,
  • the third division mode When the side length of the current coding unit's to-be-divided side is less than T, use a third division mode to divide the luminance block of the current coding unit, where the division direction of the third division mode is perpendicular to the current coding unit
  • an embodiment of the present application provides a video decoding method, including:
  • the size information of the current coding unit determine whether the current coding unit satisfies the condition of dividing the luminance block of the current coding unit into at least two luminance prediction blocks, and the condition includes at least one of the following conditions:
  • Condition 1 The value of the aspect ratio of the current coding unit is greater than or equal to 1/N and less than or equal to N, where N is a positive number;
  • the maximum side length of the current coding unit is a first threshold, and the first threshold is a positive number;
  • the width-to-height ratio of the divided luminance prediction block is greater than or equal to 1/M, and less than or equal to M, where M is a positive number ,
  • the width-to-height ratio of the divided luma prediction block is obtained according to the size information of the current coding unit;
  • Condition 4 If the luminance block of the current coding unit is divided into at least two luminance prediction blocks, the width and height of the divided luminance prediction block are both greater than or equal to a second threshold, and the second threshold is a positive integer , The width and height of the divided luma prediction block are obtained according to the size information of the current coding unit;
  • the minimum side length of the current coding unit is a third threshold, and if the luminance block of the current coding unit is divided into at least two luminance prediction blocks, the width and height of the divided luminance prediction block are greater than Or equal to a fourth threshold, the third threshold is a positive integer, the fourth threshold is a positive integer, and the width and height of the divided luminance prediction block are obtained according to the size information of the current coding unit;
  • the size information of the prediction unit of the current coding unit is obtained.
  • the prediction information of the current coding unit is obtained according to the size information of the prediction unit of the current coding unit.
  • an embodiment of the present application provides a video decoding method.
  • the method includes:
  • the luminance transformation block is obtained in at least one of the following ways:
  • Manner 1 In the case that the current coding unit uses the intra prediction method for prediction, if the first division method is vertical quartering or asymmetric vertical bisection, the luminance block is vertically quartered Dividing in a divided manner to obtain the brightness transform block;
  • Method 2 In the case that the current coding unit uses the intra prediction method for prediction, if the first division method is horizontal quartering or asymmetric horizontal bisection, the luminance block is divided into four equal divisions Obtaining the brightness transform block;
  • Manner 3 In the case that the current coding unit uses the inter prediction method for prediction, if the first division method is vertical quartering or asymmetric vertical bisection, the luminance block is vertically divided into four equal parts Dividing by way of obtaining the brightness transform block or using the brightness block as the brightness transform block;
  • a reconstructed block of the luminance block is obtained.
  • an embodiment of the present application provides a video decoding method.
  • the method includes:
  • the chroma transformation block of the current coding unit is obtained in at least one of the following ways:
  • Method 1 When the current coding unit uses the intra prediction method for prediction, use the chroma block of the current coding unit as the chroma transform block;
  • a reconstructed block of the chroma block is obtained.
  • a decoding apparatus including the first aspect or the second aspect or the third aspect or the fourth aspect, or the first aspect or the second aspect or the third aspect or the fourth aspect
  • the module of the method in any implementation mode.
  • a decoder includes: a nonvolatile memory and a processor coupled to each other, and the processor calls program codes stored in the memory to perform the first aspect or the second
  • the aspect or the third aspect or the fourth aspect, or the first aspect or the second aspect or the third aspect or the fourth aspect may implement some or all steps of the method.
  • a computer-readable storage medium storing program code, wherein the program code includes a method for performing the first aspect or the second aspect or the third aspect or the fourth aspect , Or instructions of some or all steps of the method in any one of the implementation manners of the first aspect, the second aspect, the third aspect, or the fourth aspect.
  • a computer program product that, when the computer program product runs on a computer, causes the computer to execute the first aspect or the second aspect or the third aspect or the fourth aspect, or the first aspect or the first aspect
  • the instructions in part or all of the steps in the method in any of the second aspect or the third aspect or the fourth aspect.
  • the present application also provides an image reconstruction method and device, which can reduce the complexity of video encoding and decoding and improve encoding and decoding performance.
  • an image reconstruction method includes: obtaining a prediction mode of a current coding unit, and/or obtaining a prediction division method of the current coding unit, the current coding unit including a luminance coding block and color Degree coding block, the prediction division method is a method of dividing the current coding unit into a prediction block or a prediction unit; according to the prediction division method and/or the prediction mode, a transform block of the current coding unit is obtained; According to the transform block, a reconstructed image block of the current coding unit is generated.
  • the transform block of the current coding unit can be obtained, At this time, generating the reconstructed image block of the current coding unit according to the transform block can reduce the complexity of video encoding and decoding, and improve the encoding and decoding efficiency.
  • the prediction division mode of the current coding unit may be determined according to the prediction mode.
  • the prediction mode may include an intra prediction mode and an inter prediction mode.
  • the obtaining the transform block of the current coding unit according to the prediction division mode and/or the prediction mode includes: according to the prediction division mode And/or the prediction mode, dividing the current coding unit into transform blocks.
  • the current coding unit can be divided into transform blocks Therefore, the complexity of video encoding and decoding can be reduced, and the encoding and decoding efficiency can be improved.
  • the obtaining the prediction mode of the current coding unit includes: parsing or deriving the prediction mode from a code stream, and the prediction mode includes an intra prediction mode And inter prediction modes.
  • the prediction mode obtained by parsing or deriving from the code stream mentioned above can be executed by the decoder.
  • the prediction mode may be directly obtained.
  • the obtaining the prediction division mode of the current coding unit includes: determining a candidate that the current coding unit is allowed to use according to the size of the current coding unit Prediction division method; determining the prediction division method from the allowed candidate prediction division methods.
  • the prediction division mode can be determined, therefore, the video coding can be reduced.
  • the complexity of decoding improves coding and decoding efficiency.
  • the acquiring the prediction division mode of the current coding unit includes: determining the prediction division of the current coding unit according to the size of the current coding unit the way.
  • the prediction division method can be determined directly according to the size of the current coding unit (no need to parse the code stream or only a small amount of information in the code stream), therefore, the video can be reduced
  • the complexity of codec improves the efficiency of codec.
  • the method further includes: when the prediction mode is an intra prediction mode, dividing the luminance coding block using the prediction division mode , A luma prediction block is obtained, the chroma coding block is not divided, and the chroma coding block is used as a chroma prediction block.
  • the method further includes: in a case where the prediction mode is an inter prediction mode, not dividing the current coding unit, and dividing the current coding unit
  • the coding unit serves as a prediction unit.
  • the current coding unit is not divided, which can avoid the generation of an encoding block that is too small in size, and can improve codec efficiency.
  • the method further includes: when the prediction mode is an inter prediction mode, dividing the current coding unit in any of the following ways : Use the prediction division method to divide the luma coding block to obtain a luma prediction block, use the prediction division method to divide the chroma coding block to obtain a chroma prediction block; or use the prediction division method Divide the luma coding block to obtain a luma prediction block.
  • the prediction mode is an inter prediction mode
  • dividing the current coding unit in any of the following ways : Use the prediction division method to divide the luma coding block to obtain a luma prediction block, use the prediction division method to divide the chroma coding block to obtain a chroma prediction block; or use the prediction division method Divide the luma coding block to obtain a luma prediction block.
  • the prediction mode is an inter prediction mode
  • dividing the current coding unit in any of the following ways : Use the prediction division method to divide the luma coding block to obtain a luma prediction
  • the obtaining the transform block of the current coding unit according to the prediction division mode and/or the prediction mode includes: in the prediction mode is In the intra prediction mode, and when the prediction division method of the luminance coding block is vertical quartile or asymmetric vertical bisector, the vertical quartile is used to divide the luminance coding block to obtain luminance Transform block, do not divide the chroma coding block, and use the chroma coding block as a chroma transform block; or the prediction mode is an intra prediction mode, and the prediction division method of the luma coding block is In the case of horizontal quartiles or asymmetric horizontal halves, use the horizontal quartiles to divide the luma coding block to obtain a luma transform block, do not divide the chroma coding block, and use the chroma coding block as the color Degree transformation block.
  • the transform block of the current coding unit is obtained directly according to the prediction division method and/or the prediction mode (no need to parse the code stream or only a small amount of information in the code stream), so , Can reduce the complexity of video encoding and decoding, and improve encoding and decoding efficiency.
  • the obtaining the transform block of the current coding unit according to the prediction division mode and/or the prediction mode includes: in the prediction mode is In the case of the inter prediction mode, the current coding unit is not divided, and the current coding unit is used as a transformation unit.
  • the transform block of the current coding unit is obtained directly according to the prediction division method and/or the prediction mode (no need to parse the code stream or only a small amount of information in the code stream), so , Can reduce the complexity of video encoding and decoding, and improve encoding and decoding efficiency.
  • the method further includes: determining whether to allow the current coding unit to be divided if the size of the current coding unit satisfies at least one of the following conditions To obtain a prediction block: the ratio of the width and height of the current coding unit is less than P, where P is a positive integer; or the maximum side length of the current coding unit is equal to a preset threshold; when it is determined that the current coding is allowed Only when the unit is divided to obtain a prediction block, the prediction division mode of acquiring the current coding unit is executed.
  • the size of the current coding unit it can be determined whether the current coding unit is allowed to be divided to obtain a prediction block. Therefore, the complexity of video encoding and decoding can be reduced and the encoding and decoding efficiency can be improved. .
  • an image reconstruction device including: an acquisition unit for acquiring a prediction mode of a current coding unit, and/or a prediction division mode of the current coding unit, the current coding unit including luminance coding Block and chroma coding block, the prediction division method is a method of dividing the current coding unit into a prediction block or a prediction unit; a processing unit is used to obtain all data according to the prediction division method and/or the prediction mode A transform block of the current coding unit; a reconstruction unit, configured to generate a reconstructed image block of the current coding unit according to the transform block.
  • the transform block of the current coding unit can be obtained, At this time, generating the reconstructed image block of the current coding unit according to the transform block can reduce the complexity of video encoding and decoding, and improve the encoding and decoding efficiency.
  • the prediction division mode of the current coding unit may be determined according to the prediction mode.
  • the prediction mode may include an intra prediction mode and an inter prediction mode.
  • the processing unit is specifically configured to divide the current coding unit into transform blocks according to the prediction division mode and/or the prediction mode.
  • the current coding unit may be divided into transform blocks, therefore, the complexity of video encoding and decoding can be reduced, and the encoding and decoding efficiency can be improved.
  • the acquiring unit is specifically configured to: parse or derive the prediction mode from a code stream, and the prediction mode includes an intra prediction mode and an inter prediction mode.
  • the prediction mode obtained by parsing or deriving from the code stream mentioned above can be executed by the decoder.
  • the prediction mode may be directly obtained.
  • the acquisition unit is specifically configured to: determine, according to the size of the current coding unit, a candidate prediction division method allowed by the current coding unit; from the The prediction division mode is determined from the candidate prediction division modes allowed to be used.
  • the prediction division mode can be determined, therefore, the video coding can be reduced.
  • the complexity of decoding improves coding and decoding efficiency.
  • the acquisition unit is specifically configured to: determine the prediction division manner of the current coding unit according to the size of the current coding unit.
  • the prediction division method can be determined directly according to the size of the current coding unit (no need to parse the code stream or only a small amount of information in the code stream), therefore, the video can be reduced
  • the complexity of codec improves the efficiency of codec.
  • the processing unit is further configured to: when the prediction mode is an intra prediction mode, use the prediction division method to encode the luminance block Performing division to obtain a luma prediction block, without dividing the chroma coding block, and using the chroma coding block as a chroma prediction block.
  • the processing unit is further configured to: when the prediction mode is an inter prediction mode, do not divide the current coding unit, and divide all The current coding unit is used as a prediction unit.
  • the current coding unit is not divided, which can avoid the generation of an encoding block that is too small in size, and can improve codec efficiency.
  • the processing unit is further configured to: when the prediction mode is the inter prediction mode, perform the current coding unit in any one of the following ways Divide: use the prediction division method to divide the luma coding block to obtain a luma prediction block, use the prediction division method to divide the chroma coding block to obtain a chroma prediction block; or use the prediction A division method divides the luminance coding block to obtain a luminance prediction block, when there are two luminance prediction blocks and at least one side of at least one luminance prediction block of the two luminance prediction blocks is 4 , The chroma coding block is not divided, and the chroma coding block is used as a chroma prediction block.
  • the processing unit is specifically configured to: when the prediction mode is an intra prediction mode, and the prediction division manner of the luminance coding block is vertical In the case of quadrant or asymmetrical vertical dichotomy, the vertical quadrant is used to divide the luma coding block to obtain a luma transform block, the chroma coding block is not divided, and the chroma coding block is used as Chroma transform block; or when the prediction mode is an intra prediction mode, and the prediction division of the luma coding block is horizontal quartile or asymmetric horizontal halving, use horizontal quartile
  • the luma coding block is divided to obtain a luma transform block, the chroma coding block is not divided, and the chroma coding block is used as a chroma transform block.
  • the transform block of the current coding unit is obtained directly according to the prediction division method and/or the prediction mode (no need to parse the code stream or only a small amount of information in the code stream), so , Can reduce the complexity of video encoding and decoding, and improve encoding and decoding efficiency.
  • the processing unit is specifically configured to: when the prediction mode is an inter prediction mode, do not divide the current coding unit and divide all
  • the current coding unit is described as a transformation unit.
  • the transform block of the current coding unit is obtained directly according to the prediction division method and/or the prediction mode (no need to parse the code stream or only a small amount of information in the code stream), so , Can reduce the complexity of video coding and decoding, improve coding and decoding efficiency.
  • the processing unit is further configured to: when the size of the current coding unit meets at least one of the following conditions, determine whether to allow the current coding unit Divide to obtain a prediction block: the ratio of the width and height of the current coding unit is less than P, where P is a positive integer; or the maximum side length of the current coding unit is equal to a preset threshold; Only when the current coding unit is divided to obtain the prediction block, the method of obtaining the prediction division of the current coding unit is executed.
  • the size of the current coding unit it can be determined whether the current coding unit is allowed to be divided to obtain a prediction block. Therefore, the complexity of video encoding and decoding can be reduced and the encoding and decoding efficiency can be improved. .
  • a device for decoding video data includes:
  • Memory used to store video data in the form of code stream
  • the video decoder is used to implement part or all of the steps of any method of the ninth aspect.
  • a device for encoding video data includes:
  • Memory used to store video data in the form of code stream
  • a video encoder for implementing part or all of the steps of any method of the ninth aspect.
  • an embodiment of the present application provides an apparatus for decoding video data, including: a memory and a processor, where the processor calls program codes stored in the memory to perform any method of the ninth aspect Part or all steps.
  • the above memory is a non-volatile memory.
  • the aforementioned memory and processor are coupled together.
  • an embodiment of the present application provides a computer-readable storage medium that stores a program code, where the program code includes a portion for performing any method of the ninth aspect Or instructions for all steps.
  • an embodiment of the present application provides a computer program product that, when the computer program product runs on a computer, causes the computer to perform part or all of the steps of any of the methods of the ninth aspect.
  • the transform block of the current coding unit can be obtained, At this time, generating the reconstructed image block of the current coding unit according to the transform block can reduce the complexity of video encoding and decoding, and improve the encoding and decoding efficiency.
  • FIG. 1 is a block diagram of an example of a video encoding and decoding system 10 for implementing an embodiment of the present invention
  • FIG. 1B is a block diagram of an example of a video decoding system 40 for implementing an embodiment of the present invention
  • FIG. 2 is a block diagram of an example structure of an encoder 20 for implementing an embodiment of the present invention
  • FIG. 3 is a block diagram of an example structure of a decoder 30 for implementing an embodiment of the present invention.
  • FIG. 4 is a block diagram of an example of a video decoding device 400 for implementing an embodiment of the present invention
  • FIG. 5 is a block diagram of another example of an encoding device or a decoding device used to implement an embodiment of the present invention.
  • FIG. 6 is a schematic block diagram of a block division method
  • FIG. 7 is a schematic block diagram of a block division method
  • FIG. 8 is a schematic block diagram of a block division method
  • FIG. 9 is a schematic block diagram of a block division method
  • FIG. 10 is a schematic block diagram of a block division method
  • FIG. 11 is a schematic block diagram of a video communication system for implementing embodiments of the present invention.
  • FIG. 12 is a schematic flowchart of an image reconstruction method according to an embodiment of the present application.
  • FIG. 13 is a schematic diagram of four equal divisions and asymmetric divisions according to an embodiment of the present application.
  • FIG. 14 is a schematic block diagram of an image reconstruction device according to an embodiment of the present application.
  • 15 is a schematic block diagram of an image reconstruction device according to an embodiment of the present application.
  • the corresponding device may include one or more units such as functional units to perform the one or more method steps described (eg, one unit performs one or more steps , Or multiple units, each of which performs one or more of multiple steps), even if such one or more units are not explicitly described or illustrated in the drawings.
  • the corresponding method may include one step to perform the functionality of one or more units (eg, one step executes one or more units Functionality, or multiple steps, each of which performs the functionality of one or more of the multiple units), even if such one or more steps are not explicitly described or illustrated in the drawings.
  • the features of the exemplary embodiments and/or aspects described herein may be combined with each other.
  • Video coding generally refers to processing a sequence of pictures that form a video or video sequence.
  • picture In the field of video coding, the terms “picture”, “frame” or “image” may be used as synonyms.
  • Video coding as used herein means video coding or video decoding.
  • Video encoding is performed on the source side and usually includes processing (eg, by compressing) the original video picture to reduce the amount of data required to represent the video picture, thereby storing and/or transmitting more efficiently.
  • Video decoding is performed on the destination side and usually involves inverse processing relative to the encoder to reconstruct the video picture.
  • the "encoding" of video pictures involved in the embodiments should be understood as referring to the “encoding” or “decoding” of video sequences.
  • the combination of the encoding part and the decoding part is also called codec (encoding and decoding).
  • the video sequence includes a series of pictures, which are further divided into slices, and the slices are further divided into blocks.
  • Video encoding is performed in units of blocks.
  • the concept of blocks is further expanded.
  • a macroblock can be further divided into multiple prediction blocks that can be used for predictive coding.
  • basic concepts such as coding unit (CU), prediction unit (PU), and transform unit (TU) are used to functionally divide a variety of block units and adopt a new tree-based structure Describe it.
  • the CU can be divided into smaller CUs according to the quadtree, and the smaller CU can continue to be divided to form a quadtree structure.
  • the CU is the basic unit for dividing and coding the encoded image.
  • PU can correspond to the prediction block and is the basic unit of predictive coding.
  • the CU is further divided into multiple PUs according to the division mode.
  • the TU can correspond to the transform block and is the basic unit for transforming the prediction residual.
  • CU regardless of CU, PU or TU, they all belong to the concept of block (or image block) in essence.
  • the 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 use inter-picture (temporal) or intra-picture (spatial) prediction to encode picture regions.
  • Each CU can be further split into one, two, or four PUs according to the PU split type.
  • the same prediction process is applied within a PU, and related information is transmitted to the decoder on the basis of the PU.
  • the CU may be divided into transform units (TU) according to other quadtree structures similar to the coding tree used for the CU.
  • quad-tree and binary-tree (QTBT) split frames are used to split the coding blocks.
  • the CU may have a square or rectangular shape.
  • the image block to be encoded in the current encoded image may be referred to as the current block.
  • the reference block is a block that provides a reference signal for the current block, where the reference signal represents a pixel value within the image block.
  • the block in the reference image that provides the prediction signal for the current block may be a prediction block, where the prediction signal represents a pixel value or a sample value or a sample signal within the prediction block. For example, after traversing multiple reference blocks, the best reference block is found. This best reference block will provide a prediction for the current block. This block is called a prediction block.
  • the original video picture can be reconstructed, that is, 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).
  • further compression is performed by, for example, quantization to reduce the amount of data required to represent the video picture, but the decoder side cannot fully reconstruct the video picture, that is, the quality of the reconstructed video picture is better than the original video picture. The quality is lower or worse.
  • Several video coding standards of H.261 belong to "lossy hybrid video codec” (ie, combining spatial and temporal prediction in the sample domain with 2D transform coding for applying quantization in the transform domain).
  • Each picture of the video sequence is usually divided into non-overlapping block sets, which are usually encoded at the block level.
  • the encoder side usually processes the encoded video at the block (video block) level.
  • the prediction block is generated by spatial (intra-picture) prediction and temporal (inter-picture) prediction.
  • the encoder duplicates the decoder processing loop so that the encoder and decoder generate the same prediction (eg, intra prediction and inter prediction) and/or reconstruction for processing, ie, encoding subsequent blocks.
  • FIG. 1A exemplarily shows a schematic block diagram of a video encoding and decoding system 10 applied in an embodiment of the present invention.
  • the video encoding and decoding system 10 may include a source device 12 and a destination device 14, the source device 12 generates encoded video data, and therefore, the source device 12 may be referred to as a video encoding device.
  • the destination device 14 may decode the encoded video data generated by the source device 12, and therefore, the destination device 14 may be referred to as a video decoding device.
  • Various implementations of source device 12, destination device 14, or both may include one or more processors and memory coupled to the one or more processors.
  • Source device 12 and destination device 14 may include various devices, including desktop computers, mobile computing devices, notebook (eg, laptop) computers, tablet computers, set-top boxes, telephone handsets such as so-called "smart" phones, etc. Devices, televisions, cameras, display devices, digital media players, video game consoles, in-vehicle computers, wireless communication devices, or the like.
  • FIG. 1A depicts the source device 12 and the destination device 14 as separate devices
  • device embodiments may also include the functionality of the source device 12 and the destination device 14 or both, ie, the source device 12 or the corresponding Functionality of the destination device 14 or the corresponding functionality.
  • the source device 12 or corresponding functionality and the 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 can be made between the source device 12 and the destination device 14 via the link 13, and the destination device 14 can receive the encoded video data from the source device 12 via the link 13.
  • Link 13 may include one or more media or devices capable of moving encoded video data from source device 12 to destination device 14.
  • 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.
  • the source device 12 may modulate the encoded video data according to a communication standard (eg, a wireless communication protocol), and may transmit the modulated video data to the destination device 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.
  • RF radio frequency
  • 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 (eg, the Internet).
  • the one or more communication media may include routers, switches, base stations, or other devices that facilitate communication from source device 12 to destination device 14.
  • the source device 12 includes an encoder 20.
  • the source device 12 may further include a picture source 16, a picture pre-processor 18, and a communication interface 22.
  • the encoder 20, the picture source 16, the picture preprocessor 18, and the communication interface 22 may be hardware components in the source device 12, or may be software programs in the source device 12. They are described as follows:
  • Picture source 16 which can include or can be any kind of picture capture device, for example, to capture real-world pictures, and/or any kind of pictures or comments (for screen content encoding, some text on the screen is also considered to be encoded Part of the picture or image) generation device, for example, a computer graphics processor for generating computer animation pictures, or for acquiring and/or providing real-world pictures, computer animation pictures (for example, screen content, virtual reality, VR) pictures) in any category of equipment, and/or any combination thereof (for example, augmented reality (AR) pictures).
  • the picture source 16 may be a camera for capturing pictures or a memory for storing pictures.
  • the picture source 16 may also include any type of (internal or external) interface that stores previously captured or generated pictures and/or acquires or receives pictures.
  • the picture source 16 When the picture source 16 is a camera, the picture source 16 may be, for example, a local or integrated camera integrated in the source device; when the picture source 16 is a memory, the picture source 16 may be a local or integrated, for example, integrated in the source device Memory.
  • the interface When the picture source 16 includes an interface, the interface may be, for example, an external interface that receives pictures from an external video source.
  • the external video source is, for example, an external picture capture device, such as a camera, an external memory, or an external picture generation device.
  • the external picture generation device for example It is an external computer graphics processor, computer or server.
  • the interface may be any type of interface according to any proprietary or standardized interface protocol, such as a wired or wireless interface, an optical interface.
  • the picture can be regarded as a two-dimensional array or matrix of pixels (picture elements).
  • the pixels in the array can also be called sampling points.
  • the number of sampling points in the horizontal and vertical directions (or axes) of the array or picture defines the size and/or resolution of the picture.
  • three color components are usually used, that is, a picture can be represented or contain three sampling arrays.
  • the picture includes corresponding red, green, and blue sampling arrays.
  • each pixel is usually expressed in a brightness/chroma format or color space. For example, for a picture in YUV format, it includes the brightness component indicated by Y (sometimes also indicated by L) and the two indicated by U and V.
  • the luma component Y represents luminance or gray-scale horizontal intensity (for example, both are the same in gray-scale pictures), and the two chroma components U and V represent chroma or color information components.
  • the picture in the YUV format includes a luminance sampling array of luminance sampling values (Y), and two chrominance sampling arrays of chrominance values (U and V). RGB format pictures can be converted or transformed into YUV format and vice versa, this process is also called color transformation or conversion. If the picture is black and white, the picture may include only the brightness sampling array.
  • the picture transmitted from the picture source 16 to the picture processor may also be referred to as original picture data 17.
  • the picture pre-processor 18 is configured to receive the original picture data 17 and perform pre-processing on the original picture data 17 to obtain the pre-processed picture 19 or the pre-processed picture data 19.
  • the pre-processing performed by the picture pre-processor 18 may include trimming, color format conversion (eg, conversion from RGB format to YUV format), color grading, or denoising.
  • the encoder 20 (or video encoder 20) is used to receive the pre-processed picture data 19, and process the pre-processed picture data 19 in a related prediction mode (such as the prediction mode in various embodiments herein), thereby
  • the encoded picture data 21 is provided (the structural details of the encoder 20 will be further described below based on FIG. 2 or FIG. 4 or FIG. 5).
  • the encoder 20 may be used to execute various embodiments described below to implement the application of the chroma block prediction method described in the present invention on the encoding side.
  • the communication interface 22 can be used to receive the encoded picture data 21, and can transmit the encoded picture data 21 to the destination device 14 or any other device (such as a memory) through the link 13 for storage or direct reconstruction.
  • the other device may be any device used for decoding or storage.
  • the communication interface 22 may be used, for example, to encapsulate the encoded picture data 21 into a suitable format, such as a data packet, for transmission on the link 13.
  • the destination device 14 includes a decoder 30, and optionally, the destination device 14 may further include a communication interface 28, a picture post-processor 32, and a display device 34. They are described as follows:
  • the communication interface 28 may be used to receive the encoded picture data 21 from the source device 12 or any other source, such as a storage device, such as an encoded picture data storage device.
  • the communication interface 28 can be used to transmit or receive the encoded picture data 21 via the link 13 between the source device 12 and the destination device 14 or via any type of network.
  • the link 13 is, for example, a direct wired or wireless connection.
  • the category of network is, for example, a wired or wireless network or any combination thereof, or any category of private and public networks, or any combination thereof.
  • the communication interface 28 may be used, for example, to decapsulate the data packet transmitted by the communication interface 22 to obtain the encoded picture data 21.
  • Both the communication interface 28 and the communication interface 22 can be configured as a one-way communication interface or a two-way communication interface, and can be used, for example, to send and receive messages to establish a connection, confirm and exchange any other communication link and/or for example encoded picture data Information about data transmission.
  • the decoder 30 (or referred to as the decoder 30) is used to receive the encoded picture data 21 and provide the decoded picture data 31 or the decoded picture 31 (hereinafter, the decoder 30 will be further described based on FIG. 3 or FIG. 4 or FIG. 5 Structural details).
  • the decoder 30 may be used to execute various embodiments described below to implement the application of the chroma block prediction method described in the present invention on the decoding side.
  • the post-picture processor 32 is configured to perform post-processing on the decoded picture data 31 (also referred to as reconstructed picture data) to obtain post-processed picture data 33.
  • the post-processing performed by the image post-processor 32 may include: color format conversion (for example, conversion from YUV format to RGB format), color adjustment, retouching or resampling, or any other processing, and may also be used to convert the post-processed image data 33 Transmission to the display device 34.
  • the display device 34 is used to receive post-processed picture data 33 to display pictures to, for example, a user or a viewer.
  • the display device 34 may be or may include any type of display for presenting reconstructed pictures, for example, an integrated or external display or monitor.
  • the display may include a liquid crystal display (liquid crystal display, LCD), an organic light emitting diode (organic light emitting diode, OLED) display, a plasma display, a projector, a micro LED display, a liquid crystal on silicon (LCoS), Digital Light Processor (DLP) or other displays of any kind.
  • FIG. 1A depicts source device 12 and destination device 14 as separate devices
  • device embodiments may also include the functionality of source device 12 and destination device 14 or both, ie source device 12 or The corresponding functionality and the destination device 14 or corresponding functionality.
  • the source device 12 or corresponding functionality and the 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 .
  • Source device 12 and destination device 14 may include any of a variety of devices, including any type of handheld or stationary device, for example, notebook or laptop computers, mobile phones, smartphones, tablets or tablet computers, cameras, desktops Computers, set-top boxes, televisions, cameras, in-vehicle devices, display devices, digital media players, video game consoles, video streaming devices (such as content service servers or content distribution servers), broadcast receiver devices, broadcast transmitter devices And so on, and can not use or use any kind of operating system.
  • handheld or stationary device for example, notebook or laptop computers, mobile phones, smartphones, tablets or tablet computers, cameras, desktops Computers, set-top boxes, televisions, cameras, in-vehicle devices, display devices, digital media players, video game consoles, video streaming devices (such as content service servers or content distribution servers), broadcast receiver devices, broadcast transmitter devices And so on, and can not use or use any kind of operating system.
  • Both the encoder 20 and the decoder 30 can be implemented as any of various suitable circuits, for example, one or more microprocessors, digital signal processors (DSPs), application-specific integrated circuits (application-specific integrated circuits) circuit, ASIC), field-programmable gate array (FPGA), discrete logic, hardware, or any combination thereof.
  • DSPs digital signal processors
  • ASIC application-specific integrated circuits
  • FPGA field-programmable gate array
  • the device may store the instructions of the software in a suitable non-transitory computer-readable storage medium, and may use one or more processors to execute the instructions in hardware to perform the techniques of the present disclosure . Any one of the foregoing (including hardware, software, a combination of hardware and software, etc.) may be regarded as one or more processors.
  • the video encoding and decoding system 10 shown in FIG. 1A is only an example, and the technology of the present application may be applied to video encoding settings that do not necessarily include any data communication between encoding and decoding devices (for example, video encoding or video decoding).
  • data can be retrieved from local storage, streamed on the network, and so on.
  • the video encoding device may encode the data and store the data to the memory, and/or the video decoding device may retrieve the data from the memory and decode the data.
  • encoding and decoding are performed by devices that do not communicate with each other but only encode data to and/or retrieve data from memory and decode the data.
  • FIG. 1B is an explanatory 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 exemplary embodiment.
  • the video decoding system 40 can implement a combination of various technologies in the embodiments of the present invention.
  • the video decoding system 40 may include an imaging device 41, an encoder 20, a decoder 30 (and/or a video encoder/decoder implemented by the logic circuit 47 of the processing unit 46), an antenna 42 , One or more processors 43, one or more memories 44, and/or display devices 45.
  • the imaging device 41, the antenna 42, the processing unit 46, the logic circuit 47, the encoder 20, the decoder 30, the processor 43, the memory 44, and/or the display device 45 can communicate with each other.
  • the video coding system 40 is shown with the encoder 20 and the decoder 30, in different examples, the video coding system 40 may include only the encoder 20 or only the decoder 30.
  • antenna 42 may be used to transmit or receive an encoded bitstream of video data.
  • the display device 45 may be used to present video data.
  • the logic circuit 47 may be implemented by the processing unit 46.
  • the processing unit 46 may include application-specific integrated circuit (ASIC) logic, a graphics processor, a general-purpose processor, and the like.
  • the video decoding system 40 may also include an optional processor 43, which may similarly include application-specific integrated circuit (ASIC) logic, a graphics processor, a general-purpose processor, and the like.
  • the logic circuit 47 may be implemented by hardware, such as dedicated hardware for video encoding, and the processor 43 may be implemented by general-purpose software, an operating system, and so on.
  • the memory 44 may be any type of memory, such as volatile memory (for example, static random access memory (Static Random Access Memory, SRAM), dynamic random access memory (Dynamic Random Access Memory, DRAM), etc.) or non-volatile Memory (for example, flash memory, etc.), etc.
  • volatile memory for example, static random access memory (Static Random Access Memory, SRAM), dynamic random access memory (Dynamic Random Access Memory, DRAM), etc.
  • non-volatile Memory for example, flash memory, etc.
  • the memory 44 may be implemented by cache memory.
  • the logic circuit 47 can access the memory 44 (eg, to implement an image buffer).
  • the logic circuit 47 and/or the processing unit 46 may include memory (eg, cache, etc.) for implementing image buffers and the like.
  • the encoder 20 implemented by a logic circuit may include an image buffer (eg, implemented by the processing unit 46 or the memory 44) and a graphics processing unit (eg, implemented by the processing unit 46).
  • the graphics processing unit may be communicatively coupled to the image buffer.
  • the graphics processing unit may include the encoder 20 implemented by a logic circuit 47 to implement the various modules discussed with reference to FIG. 2 and/or any other encoder system or subsystem described herein.
  • Logic circuits can be used to perform the various operations discussed herein.
  • decoder 30 may be implemented by logic circuit 47 in a similar manner to implement the various modules discussed with reference to decoder 30 of FIG. 3 and/or any other decoder systems or subsystems described herein.
  • the decoder 30 implemented by the logic circuit may include an image buffer (implemented by the processing unit 2820 or the memory 44) and a graphics processing unit (for example, implemented by the processing unit 46).
  • the graphics processing unit may be communicatively coupled to the image buffer.
  • the graphics processing unit may include a decoder 30 implemented by a logic circuit 47 to implement various modules discussed with reference to FIG. 3 and/or any other decoder system or subsystem described herein.
  • antenna 42 may be used to receive an encoded bitstream of video data.
  • the encoded bitstream may include data related to encoded video frames, indicators, index values, mode selection data, etc. discussed herein, such as data related to encoded partitions (eg, transform coefficients or quantized transform coefficients , (As discussed) optional indicators, and/or data that defines the code segmentation).
  • the video coding system 40 may also include a decoder 30 coupled to the antenna 42 and used to decode the encoded bitstream.
  • the display device 45 is used to present video frames.
  • the decoder 30 may be used to perform the reverse process.
  • the decoder 30 may be used to receive and parse such syntax elements and decode the relevant video data accordingly.
  • encoder 20 may entropy encode syntax elements into an encoded video bitstream. In such instances, decoder 30 may parse such syntax elements and decode relevant video data accordingly.
  • the decoding method described in this embodiment of the present invention is mainly used in a decoding process, and this process exists in both the encoder 20 and the decoder 30.
  • FIG. 2 shows a schematic/conceptual block diagram of an example of an encoder 20 for implementing an embodiment of the present invention.
  • 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, decoded picture buffer (DPB) 230, prediction processing unit 260, and entropy encoding unit 270.
  • the prediction processing unit 260 may include an inter prediction unit 244, an intra prediction unit 254, and a mode selection unit 262.
  • the 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 based on a hybrid video codec.
  • 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 the forward signal path of the encoder 20, while, for example, the inverse quantization unit 210, the inverse transform processing unit 212, the heavy
  • the structural unit 214, the buffer 216, the loop filter 220, the decoded picture buffer (DPB) 230, and the prediction processing unit 260 form a backward signal path of the encoder, where the backward signal path of the encoder corresponds The signal path for the decoder (see decoder 30 in FIG. 3).
  • the encoder 20 receives a picture 201 or an image block 203 of the picture 201 through, for example, an input 202, for example, forming a picture in a picture sequence of a video or a video sequence.
  • the image block 203 may also be referred to as a current picture block or a picture block to be coded
  • the picture 201 may be referred to as a current picture or a picture to be coded (especially when the current picture is distinguished from other pictures in video coding, other pictures such as the same video sequence That is, the previously encoded and/or decoded pictures in the video sequence of the current picture are also included).
  • An embodiment of the encoder 20 may include a division unit (not shown in FIG. 2) for dividing the picture 201 into a plurality of blocks such as an image block 203, usually into a plurality of non-overlapping blocks.
  • the segmentation unit can be used to use the same block size and corresponding grid that defines the block size for all pictures in the video sequence, or to change the block size between pictures or subsets or picture groups, and divide each picture into The corresponding block.
  • the prediction processing unit 260 of the encoder 20 may be used to perform any combination of the above-mentioned segmentation techniques.
  • image block 203 is also or can be regarded as a two-dimensional array or matrix of sampling points with sample values, although its size is smaller than picture 201.
  • the image block 203 may include, for example, one sampling array (for example, the brightness array in the case of a black and white picture 201) or three sampling arrays (for example, one brightness array and two chroma arrays in the case of a color picture) or An array of any other number and/or category 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 shown in FIG. 2 is used to encode the picture 201 block by block, for example, to perform encoding and prediction on each image block 203.
  • the residual calculation unit 204 is used to calculate the 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), for example, by subtracting the sample value of the picture image block 203 sample by sample (pixel by pixel) The sample values of the block 265 are depredicted to obtain the residual block 205 in the sample domain.
  • the transform processing unit 206 is used to apply a transform such as discrete cosine transform (DCT) or discrete sine transform (DST) to the sample values of the residual block 205 to obtain transform coefficients 207 in the transform domain .
  • the transform coefficient 207 may also be referred to as a transform residual coefficient, and represents a 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 by AVS, AVS2, and AVS3. Compared with the orthogonal DCT transform, this integer approximation is usually scaled by a factor. In order to maintain the norm of the residual block processed by the forward and inverse transform, an additional scaling factor is applied as part of the transform process.
  • the scaling factor is usually selected based on certain constraints, for example, the scaling factor is a power of two used for the shift operation, the bit depth of the transform coefficient, the accuracy, and the trade-off between implementation cost and so on.
  • a specific scaling factor can be specified for the inverse transform by the inverse transform processing unit 212 on the decoder 30 side (and corresponding inverse transform by the inverse transform processing unit 212 on the encoder 20 side), and accordingly, the encoder can be The 20 side specifies the corresponding scaling factor for the positive transform by the transform processing unit 206.
  • the quantization unit 208 is used to quantize the transform coefficient 207 by, for example, applying scalar quantization or vector quantization to obtain the quantized transform coefficient 209.
  • the quantized transform coefficient 209 may also be referred to as the quantized residual coefficient 209.
  • the quantization process can reduce the bit depth associated with some or all of the transform coefficients 207. For example, n-bit transform coefficients can be rounded down to m-bit transform coefficients during quantization, where n is greater than m.
  • the degree of quantization can be modified by adjusting the quantization parameter (QP). For example, for scalar quantization, different scales can be applied to achieve thinner or coarser quantization. Smaller quantization steps correspond to finer quantization, while larger quantization steps correspond to coarser quantization.
  • a suitable quantization step size can be indicated by a quantization parameter (QP).
  • the quantization parameter may be an index of a predefined set of suitable quantization steps.
  • smaller quantization parameters may correspond to fine quantization (smaller quantization step size)
  • larger quantization parameters may correspond to coarse quantization (larger quantization step size)
  • the quantization may include dividing by the quantization step size and the corresponding quantization or inverse quantization performed by, for example, inverse quantization 210, or may include multiplying the quantization step size.
  • AVS AVS2, AVS3, quantization parameters can be used to determine the quantization step size.
  • the quantization step size can be calculated based on the quantization parameter using fixed-point approximation that includes equations for division. Additional scaling factors can be introduced for quantization and inverse quantization to restore the norm of the residual block that may be modified due to the scale used in the fixed-point approximation of the equations for quantization step size and quantization parameter.
  • the scale of inverse transform and inverse quantization may be combined.
  • a custom quantization table can be used and signaled from the encoder to the decoder in a bitstream, for example. Quantization is a lossy operation, where the larger the quantization step, the greater the loss.
  • the inverse quantization unit 210 is used to apply the inverse quantization of the quantization unit 208 on the quantized coefficients to obtain the inverse quantized coefficients 211, for example, based on or using the same quantization step size as the quantization unit 208, apply the quantization scheme applied by the quantization unit 208 Inverse quantization scheme.
  • the inverse quantized coefficient 211 may also be referred to as the inverse quantized residual coefficient 211, which corresponds to the transform coefficient 207, although the loss due to quantization is usually not the same as the transform coefficient.
  • the inverse transform processing unit 212 is used to apply the inverse transform of the transform applied by the transform processing unit 206, for example, inverse discrete cosine transform (DCT) or inverse discrete sine transform (DST), in the sample domain
  • the inverse transform block 213 is obtained.
  • 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 (eg, summer 214) is used to add the inverse transform block 213 (ie, the reconstructed residual block 213) to the prediction block 265 to obtain the reconstructed block 215 in the sample domain, for example, The sample values of the reconstructed residual block 213 and the sample values of the prediction block 265 are added.
  • 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, for example, intra prediction.
  • the encoder may be used to use the unfiltered reconstructed blocks and/or corresponding sample values stored in the buffer unit 216 for any type of estimation and/or prediction, such as intra prediction.
  • an embodiment of the encoder 20 may be configured such that the buffer unit 216 is used not only for storing the reconstructed block 215 for intra prediction 254, but also for the loop filter unit 220 (not shown in FIG. 2) Out), and/or, for example, causing the buffer unit 216 and the decoded picture buffer unit 230 to form a buffer.
  • Other embodiments may be used to use the filtered block 221 and/or blocks or samples from the decoded picture buffer 230 (neither shown in FIG. 2) as an input or basis for intra prediction 254.
  • the loop filter unit 220 (or simply “loop filter” 220) is used to filter the reconstructed block 215 to obtain the filtered block 221, so as to smoothly perform pixel conversion or improve video quality.
  • the loop filter unit 220 is intended to represent one or more loop filters, such as deblocking filters, sample-adaptive offset (SAO) filters, or other filters, such as bilateral filters, Adaptive loop filter (adaptive loop filter, ALF), or sharpening or smoothing filter, or collaborative filter.
  • the loop filter unit 220 is shown as an in-loop filter in FIG. 2, in other configurations, the loop filter unit 220 may be implemented as a post-loop filter.
  • the filtered block 221 may also be referred to as the filtered reconstructed block 221.
  • the decoded picture buffer 230 may store the reconstructed coding block after the loop filter unit 220 performs a filtering operation on the reconstructed coding block.
  • Embodiments of the encoder 20 may be used to output loop filter parameters (eg, sample adaptive offset information), for example, directly output or by the entropy encoding unit 270 or any other
  • the entropy coding unit outputs after entropy coding, for example, so that the decoder 30 can receive and apply the same loop filter parameters for decoding.
  • the decoded picture buffer (DPB) 230 may be a reference picture memory for storing reference picture data for the encoder 20 to encode video data.
  • DPB 230 can be formed by any of a variety of memory devices, such as dynamic random access memory (dynamic random access (DRAM) (including synchronous DRAM (synchronous DRAM, SDRAM), magnetoresistive RAM (magnetoresistive RAM, MRAM), resistive RAM (resistive RAM, RRAM)) or other types of memory devices.
  • DRAM dynamic random access
  • the DPB 230 and the buffer 216 may be provided by the same memory device or separate memory devices.
  • a decoded picture buffer (DPB) 230 is used to store the filtered block 221.
  • the decoded picture buffer 230 may be further used to store other previous filtered blocks of the same current picture or different pictures such as previous reconstructed pictures, such as the previously reconstructed and filtered block 221, and may provide the complete previous The reconstructed ie decoded pictures (and corresponding reference blocks and samples) and/or partially reconstructed current pictures (and corresponding reference blocks and samples), for example for inter prediction.
  • a decoded picture buffer (DPB) 230 is used to store the reconstructed block 215.
  • the prediction processing unit 260 also known as the block prediction processing unit 260, is used to receive or acquire the image block 203 (current image block 203 of the current picture 201) and reconstructed picture data, such as the same (current) picture from the buffer 216 Reference samples and/or reference picture data 231 of one or more previously decoded pictures from the decoded picture buffer 230, and used to process such data for prediction, that is, to provide an inter prediction block 245 or The prediction block 265 of the intra prediction block 255.
  • the mode selection unit 262 may be used to select a prediction mode (eg, intra or inter prediction mode) and/or the corresponding prediction block 245 or 255 used as the prediction block 265 to calculate the residual block 205 and reconstruct the reconstructed block 215.
  • a prediction mode eg, intra or inter prediction mode
  • the corresponding prediction block 245 or 255 used as the prediction block 265 to calculate the residual block 205 and reconstruct the reconstructed block 215.
  • An embodiment of the mode selection unit 262 may be used to select a prediction mode (eg, from those prediction modes supported by the prediction processing unit 260), which provides the best match or the minimum residual (the minimum residual means Better compression in transmission or storage), or provide minimum signaling overhead (minimum signaling overhead means better compression in transmission or storage), or consider or balance both at the same time.
  • the mode selection unit 262 may be used to determine a prediction mode based on rate distortion optimization (RDO), that is, to select a prediction mode that provides minimum bit rate distortion optimization, or to select a prediction mode in which the related rate distortion at least meets the prediction mode selection criteria .
  • RDO rate distortion optimization
  • the encoder 20 is used to determine or select the best or optimal prediction mode from the (predetermined) prediction mode set.
  • the set of prediction modes 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 the developing H.266.
  • non-directional modes such as DC (or mean) mode and planar mode
  • directional modes as defined in the developing H.266.
  • the set of inter prediction modes depends on the available reference pictures (ie, for example, the aforementioned at least partially decoded pictures stored in DBP 230) and other inter prediction parameters, for example, depending on whether the entire reference picture is used or only used A part of the reference picture, for example a search window area surrounding the area of the current block, to search for the best matching reference block, and/or for example depending on whether pixel interpolation such as half-pixel and/or quarter-pixel interpolation is applied.
  • the set of inter prediction modes may include, for example, advanced motion vector (Advanced Motion Vector Prediction, AMVP) mode and merge mode.
  • AMVP Advanced Motion Vector Prediction
  • the set of inter prediction modes may include an improved control point-based AMVP mode according to an embodiment of the present invention, and an improved control point-based merge mode.
  • intra prediction unit 254 may be used to perform any combination of inter prediction techniques described below.
  • the embodiments of the present invention may also apply skip mode and/or direct mode.
  • the prediction processing unit 260 may be further used to split the image block 203 into smaller block partitions or sub-blocks, for example, iteratively using quad-tree (QT) segmentation, binary-tree (BT) segmentation Or triple-tree (TT) or extended quad-tree (EQT, Extended Quad-Tree) segmentation, or any combination thereof, and for performing predictions for each of block partitions or sub-blocks, for example, where mode selection This includes selecting the tree structure of the divided image block 203 and selecting the prediction mode applied to each of the block partitions or sub-blocks.
  • QT quad-tree
  • BT binary-tree
  • TT triple-tree
  • EQT Extended Quad-Tree
  • 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 acquire a picture image block 203 (current picture image block 203 of the current picture 201) and a decoded picture 231, or at least one or more previously reconstructed blocks, for example, one or more other/different
  • the reconstructed block of the previously decoded picture 231 is used for motion estimation.
  • the video sequence may include the current picture and the 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 that form the video sequence.
  • the encoder 20 may be used to select a reference block from multiple reference blocks of the same or different pictures in multiple other pictures, and provide a reference picture and/or provide a reference to a motion estimation unit (not shown in FIG. 2)
  • the offset (spatial offset) between the position of the block (X, Y coordinates) and the position of the current block is used as an inter prediction parameter. This offset is also called motion vector (MV).
  • the motion compensation unit is used to acquire inter prediction parameters and perform inter prediction based on or using inter prediction parameters to obtain inter prediction blocks 245.
  • the motion compensation performed by the motion compensation unit may include extracting or generating a prediction block based on a motion/block vector determined by motion estimation (possibly performing interpolation of sub-pixel accuracy). Interpolation filtering can generate additional pixel samples from known pixel samples, potentially increasing the number of candidate prediction blocks that can be used to encode picture blocks.
  • the motion compensation unit 246 may locate the prediction block pointed to by the motion vector in a reference picture list. Motion compensation unit 246 may also generate syntax elements associated with blocks and video slices for use by decoder 30 when decoding picture blocks of video slices.
  • the above inter prediction unit 244 may transmit a syntax element to the entropy encoding unit 270, where the syntax element includes inter prediction parameters (such as an inter prediction mode selected for the current block prediction after traversing multiple inter prediction modes Instructions).
  • inter prediction parameters such as an inter prediction mode selected for the current block prediction after traversing multiple inter prediction modes Instructions.
  • the decoding terminal 30 may directly use the default prediction mode for decoding. It can be understood 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 acquire, for example, a picture block 203 (current picture block) that receives the same picture and one or more previously reconstructed blocks, such as reconstructed neighboring blocks, for intra estimation.
  • the encoder 20 may be used to select an intra prediction mode from a plurality of (predetermined) intra prediction modes.
  • Embodiments of the encoder 20 may be used to select an intra-prediction mode based on optimization criteria, for example, based on a minimum residual (eg, an intra-prediction mode that provides the prediction block 255 that is most similar to the current picture block 203) or a minimum code rate distortion.
  • a minimum residual eg, an intra-prediction mode that provides the prediction block 255 that is most similar to the current picture block 203
  • a minimum code rate distortion eg, an intra-prediction mode that provides the prediction block 255 that is most similar to the current picture block 203
  • the intra prediction unit 254 is further used to determine the intra prediction block 255 based on the intra prediction parameters of the intra prediction mode as selected. In any case, after selecting the intra-prediction mode for the block, the intra-prediction unit 254 is also used to provide the intra-prediction parameters to the entropy encoding unit 270, that is, to provide an indication of the selected intra-prediction mode for the block Information. In one example, the intra prediction unit 254 may be used to perform any combination of intra prediction techniques.
  • the above-mentioned intra-prediction unit 254 may transmit a syntax element to the entropy encoding unit 270, where the syntax element includes intra-prediction parameters (such as an intra-prediction mode selected for the current block prediction after traversing multiple intra-prediction modes) Instructions).
  • the intra prediction parameters may not be carried in the syntax element.
  • the decoding terminal 30 may directly use the default prediction mode for decoding.
  • the entropy coding unit 270 is used to encode an entropy coding algorithm or scheme (for example, variable length coding (VLC) scheme, context adaptive VLC (context adaptive VLC, CAVLC) scheme, arithmetic coding scheme, context adaptive binary arithmetic) Encoding (context adaptive) binary arithmetic coding (CABAC), syntax-based context-adaptive binary arithmetic coding (SBAC), probability interval entropy (probability interval interpartitioning entropy, PIPE) encoding or other entropy Encoding method or technique) applied to a single or all of the quantized residual coefficients 209, inter prediction parameters, intra prediction parameters and/or loop filter parameters (or not applied) to obtain the output 272 to For example, the encoded picture data 21 output in the form of an encoded bit stream 21.
  • VLC variable length coding
  • CABAC context adaptive binary arithmetic
  • SBAC syntax-based context-adaptive binary arithmetic coding
  • the encoded bitstream can be transmitted to the video decoder 30 or archived for later transmission or retrieval by the video decoder 30.
  • the entropy encoding unit 270 may also be used to entropy encode other syntax elements of the current video slice being encoded.
  • video encoder 20 may be used to encode video streams.
  • the non-transform based encoder 20 may directly quantize the residual signal without the transform processing unit 206 for certain blocks or frames.
  • the encoder 20 may have a quantization unit 208 and an inverse quantization unit 210 combined into a single unit.
  • the encoder 20 may be used to implement the encoding method described in the following embodiments.
  • the video encoder 20 can directly quantize the residual signal without processing by the transform processing unit 206, and accordingly, without processing by the inverse transform processing unit 212; or, for some For 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, quantization unit 208, inverse quantization unit 210, and inverse transform processing unit 212; or, the video encoder 20 may convert The reconstructed image block is directly stored as a reference block without processing by the 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, quantization unit 208, inverse quantization unit 210, and inverse transform processing unit 212 are optional. It should be understood that the inter prediction unit 244 and the intra prediction unit 254 may be selectively enabled according to different application scenarios.
  • FIG. 3 shows a schematic/conceptual block diagram of an example of a decoder 30 for implementing an embodiment of the present invention.
  • the video decoder 30 is used to receive encoded picture data (eg, encoded bitstream) 21, for example, encoded by the encoder 20, to obtain the decoded picture 231.
  • encoded picture data eg, encoded bitstream
  • video decoder 30 receives video data from video encoder 20, such as an encoded video bitstream and associated syntax elements representing picture blocks of the encoded video slice.
  • the decoder 30 includes an entropy decoding unit 304, an inverse quantization unit 310, an inverse transform processing unit 312, a reconstruction unit 314 (such as a summer 314), a buffer 316, a loop filter 320, a The decoded picture buffer 330 and the prediction processing unit 360.
  • the prediction processing unit 360 may include an inter prediction unit 344, an intra prediction unit 354, and a mode selection unit 362.
  • video decoder 30 may perform a decoding pass that is generally reciprocal to the encoding pass described with reference to video encoder 20 of FIG. 2.
  • the entropy decoding unit 304 is used to perform entropy decoding on the encoded picture data 21 to obtain, for example, quantized coefficients 309 and/or decoded encoding parameters (not shown in FIG. 3), for example, inter prediction, intra prediction parameters , Any or all of the loop filter parameters and/or other syntax elements (decoded).
  • the entropy decoding unit 304 is further used to forward inter prediction parameters, 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.
  • the inverse quantization unit 310 can be functionally the same as the inverse quantization unit 110
  • the inverse transform processing unit 312 can be functionally the same as the inverse transform processing unit 212
  • the reconstruction unit 314 can be functionally the same as the reconstruction unit 214
  • the buffer 316 can be functionally
  • the loop filter 320 may be functionally the same as the loop filter 220
  • the decoded picture buffer 330 may be functionally the same as the decoded picture buffer 230.
  • the prediction processing unit 360 may include an inter prediction unit 344 and an intra prediction unit 354, where the inter prediction unit 344 may be similar in function to the inter prediction unit 244, and the intra prediction unit 354 may be similar in function to the intra prediction unit 254 .
  • the prediction processing unit 360 is generally used to perform block prediction and/or obtain the prediction block 365 from the encoded data 21, and receive or obtain prediction-related parameters and/or information about the entropy decoding unit 304 (explicitly or implicitly). Information about the selected prediction mode.
  • the intra prediction unit 354 of the prediction processing unit 360 is used to signal-based the intra prediction mode and the previous decoded block from the current frame or picture. Data to generate a prediction block 365 for the picture block of the current video slice.
  • the inter prediction unit 344 eg, motion compensation unit
  • Other syntax elements generate a prediction block 365 for the video block of the current video slice.
  • a prediction block may be generated from a reference picture in a reference picture list.
  • the video decoder 30 may construct the reference frame lists: list 0 and list 1 using default construction techniques based on the reference pictures stored in the DPB 330.
  • the prediction processing unit 360 is used to determine the prediction information for the video block of the current video slice by parsing the motion vector and other syntax elements, and use the prediction information to generate the prediction block for the current video block being decoded.
  • the prediction processing unit 360 uses some received syntax elements to determine the prediction mode (e.g., intra or inter prediction) of the video block used to encode the video slice, and the inter prediction slice type ( For example, B slice, P slice, or GPB slice), construction information for one or more of the reference picture lists for slices, motion vectors for each inter-coded video block for slices, The inter prediction status and other information of each inter-coded video block of the slice to decode the video block of the current video slice.
  • the prediction mode e.g., intra or inter prediction
  • the inter prediction slice type For example, B slice, P slice, or GPB slice
  • the syntax elements received by the video decoder 30 from the bitstream include an adaptive parameter set (adaptive parameter set, APS), a sequence parameter set (SPS), and a picture parameter set (picture parameter (set, PPS) or the syntax element in one or more of the stripe headers.
  • an adaptive parameter set adaptive parameter set
  • SPS sequence parameter set
  • PPS picture parameter set
  • the inverse quantization unit 310 may be used to inverse quantize (ie, inverse quantize) the quantized transform coefficients provided in the bitstream and decoded by the entropy decoding unit 304.
  • the inverse quantization process may include using the quantization parameters calculated by the video encoder 20 for each video block in the video slice to determine the degree of quantization that should be applied and also determine the degree of inverse quantization that should be applied.
  • the inverse transform processing unit 312 is used to apply an inverse transform (eg, inverse DCT, inverse integer transform, or conceptually similar inverse transform process) to the transform coefficients, so as to generate a residual block in the pixel domain.
  • an inverse transform eg, inverse DCT, inverse integer transform, or conceptually similar inverse transform process
  • the reconstruction unit 314 (for example, the summer 314) is used to add the inverse transform block 313 (ie, the reconstructed residual block 313) to the prediction block 365 to obtain the reconstructed block 315 in the sample domain, for example, by adding The sample values of the reconstructed residual block 313 and the sample values of the prediction block 365 are added.
  • the loop filter unit 320 (during the encoding loop or after the encoding loop) is used to filter the reconstructed block 315 to obtain the filtered block 321 to smoothly perform pixel conversion or improve video quality.
  • the loop filter unit 320 may be used to perform any combination of filtering techniques described below.
  • the loop filter unit 320 is intended to represent one or more loop filters, such as deblocking filters, sample-adaptive offset (SAO) filters, or other filters, such as bilateral filters, Adaptive loop filter (adaptive loop filter, ALF), or sharpening or smoothing filter, or collaborative filter.
  • the loop filter unit 320 is shown as an in-loop filter in FIG. 3, in other configurations, the loop filter unit 320 may be implemented as a post-loop filter.
  • the decoded video block 321 in a given frame or picture is then stored in a decoded picture buffer 330 that stores reference pictures for subsequent motion compensation.
  • the decoder 30 is used, for example, to output the decoded picture 31 through the output 332 for presentation to the user or for the user to view.
  • video decoder 30 may be used to decode the compressed bitstream.
  • the decoder 30 may generate the output video stream without the loop filter unit 320.
  • the non-transform based decoder 30 may directly inversely quantize the residual signal without the inverse transform processing unit 312 for certain blocks or frames.
  • the video decoder 30 may have an inverse quantization unit 310 and an inverse transform processing unit 312 combined into a single unit.
  • the decoder 30 is used to implement the decoding method described in the embodiments below.
  • video decoder 30 may be used to decode the encoded video bitstream.
  • the video decoder 30 may generate an output video stream without being processed by the filter 320; or, for certain image blocks or image frames, the entropy decoding unit 304 of the video decoder 30 does not decode the quantized coefficients, and accordingly does not It needs to be processed by the inverse quantization unit 310 and the inverse transform processing unit 312.
  • the loop filter 320 is optional; and in the case of lossless compression, the inverse quantization unit 310 and the inverse transform processing unit 312 are optional.
  • the inter prediction unit and the intra prediction unit may be selectively enabled.
  • the processing results for a certain link can be further processed and then output to the next link, for example, in interpolation filtering, motion vector derivation or loop filtering, etc. After the link, the results of the corresponding link are further clipped or shift shifted.
  • the motion vector of the control point of the current image block derived from the motion vector of the adjacent affine coding block, or the motion vector of the sub-block of the current image block derived can be further processed, and this application does not do this limited.
  • 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 range of the motion vector is -2 ⁇ (bitDepth-1) ⁇ 2 ⁇ (bitDepth-1)-1, where the " ⁇ " symbol indicates a power. If bitDepth is 16, the value ranges from -32768 to 32767. If bitDepth is 18, the value ranges from -131072 to 131071.
  • the value of the motion vector (such as the motion vectors MV of four 4x4 sub-blocks in an 8x8 image block) is constrained so that the maximum difference between the integer parts of the four 4x4 sub-blocks MV does not exceed N pixels, for example no more than one pixel.
  • ux (vx+2 bitDepth )%2 bitDepth
  • vx is the horizontal component of the motion vector of the image block or the sub-block of the image block
  • vy is the vertical component of the motion vector of the image block or the sub-block of the image block
  • ux and uy are intermediate values
  • bitDepth represents the bit width
  • the value of vx is -32769, and 32767 is obtained by the above formula. Because in the computer, the value is stored in the form of two's complement, the complement of -32769 is 1,0111,1111,1111,1111 (17 bits), the computer handles the overflow as discarding the high bit, then the value of vx If it is 0111,1111,1111,1111, it is 32767, which is consistent with the result obtained by formula processing.
  • vx Clip3(-2 bitDepth-1 , 2 bitDepth-1 -1, vx)
  • vx is the horizontal component of the motion vector of the image block or the sub-block of the image block
  • vy is the vertical component of the motion vector of the image block or the sub-block of the image block
  • x, y, and z respectively correspond to the MV clamp
  • FIG. 4 is a schematic structural diagram of a video decoding device 400 (for example, a video encoding device 400 or a video decoding device 400) provided by an embodiment of the present invention.
  • the video coding apparatus 400 is suitable for implementing the embodiments described herein.
  • the video coding device 400 may be a video decoder (eg, decoder 30 of FIG. 1A) or a video encoder (eg, encoder 20 of FIG. 1A).
  • the video decoding device 400 may be one or more components in the decoder 30 of FIG. 1A or the encoder 20 of FIG. 1A described above.
  • the video decoding device 400 includes: an inlet port 410 for receiving data and a receiving unit (Rx) 420, a processor for processing data, a logic unit or a central processing unit (CPU) 430, and a transmitter unit for transmitting data (Tx) 440 and exit port 450, and a memory 460 for storing data.
  • the video decoding device 400 may further include a photoelectric conversion component and an electro-optical (EO) component coupled to the inlet port 410, the receiver unit 420, the transmitter unit 440, and the outlet port 450 for the outlet or inlet of the optical signal or the electrical signal.
  • EO electro-optical
  • the processor 430 is implemented by hardware and software.
  • the processor 430 may be implemented as one or more CPU chips, cores (eg, multi-core processors), FPGA, ASIC, and DSP.
  • the processor 430 communicates with the inlet port 410, the receiver unit 420, the transmitter unit 440, the outlet port 450, and the memory 460.
  • the processor 430 includes a decoding module 470 (for example, an encoding module 470 or a decoding module 470).
  • the encoding/decoding module 470 implements the embodiments disclosed herein to implement the chroma block prediction method provided by the embodiments of the present invention. For example, the encoding/decoding module 470 implements, processes, or provides various encoding operations.
  • the encoding/decoding module 470 provides a substantial improvement in the function of the video decoding device 400 and affects the conversion of the video decoding device 400 to different states.
  • the encoding/decoding module 470 is implemented with instructions stored in the memory 460 and executed by the processor 430.
  • the memory 460 includes one or more magnetic disks, tape drives, and solid state drives, and can be used as an overflow data storage device for storing programs when these programs are selectively executed, and storing instructions and data read during the execution of the programs.
  • the memory 460 may be volatile and/or non-volatile, and may be read only memory (ROM), random access memory (RAM), random access memory (ternary content-addressable memory (TCAM), and/or static Random Access Memory (SRAM).
  • FIG. 5 is a simplified block diagram of an apparatus 500 that can be used as either or both of the source device 12 and the destination device 14 in FIG. 1A according to an exemplary embodiment.
  • the device 500 can implement the technology of the present application.
  • FIG. 5 is a schematic block diagram of an implementation manner of an encoding device or a decoding device (referred to simply as a decoding device 500) according to an embodiment of the present application.
  • the decoding device 500 may include a processor 510, a memory 530, and a bus system 550.
  • the processor and the memory are connected through a bus system, the memory is used to store instructions, and the processor is used to execute the instructions stored in the memory.
  • the memory of the decoding device stores the program code, and the processor can call the program code stored in the memory to perform various video encoding or decoding methods described in this application, especially various new decoding methods. In order to avoid repetition, they are not described in detail here.
  • the processor 510 may be a central processing unit (Central Processing Unit, referred to as "CPU"), and the processor 510 may also be other general-purpose processors, digital signal processors (DSPs), dedicated integrated Circuit (ASIC), ready-made programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.
  • the 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 storage device may also be used as the memory 530.
  • the memory 530 may include code and data 531 accessed by the processor 510 using the bus 550.
  • the memory 530 may further include an operating system 533 and an application program 535 including at least one program that allows the processor 510 to perform the video encoding or decoding method described in this application (in particular, the decoding method described in this application).
  • the application program 535 may include applications 1 to N, which further include a video encoding or decoding application that performs the video encoding or decoding method described in this application (referred to as a video coding application for short).
  • the bus system 550 may also include a power bus, a control bus, and a status signal bus. However, for clear explanation, various buses are marked as the bus system 550 in the figure.
  • the decoding device 500 may also include one or more output devices, such as a display 570.
  • the display 570 may be a tactile display that combines the display with a tactile unit that operably senses touch input.
  • the display 570 may be connected to the processor 510 via the bus 550.
  • CTU coding tree unit (coding tree unit), an image is composed of multiple CTUs, a CTU usually corresponds to a square image area, including the brightness pixels and chrominance pixels in the image area (or may only contain brightness pixels , Or may only contain chroma pixels); CTU also contains syntax elements that indicate how to divide the CTU into at least one coding unit (CU), and a method of decoding each coding unit to obtain a reconstructed image.
  • CU coding unit
  • CU coding unit, usually corresponding to an A ⁇ B rectangular area, including A ⁇ B luminance pixels and its corresponding chrominance pixels, A is the width of the rectangle, B is the height of the rectangle, A and B may be the same or different
  • the values of A and B are usually integer powers of 2, such as 256, 128, 64, 32, 16, 8, and 4.
  • An encoding unit can decode to obtain a reconstructed image of an A ⁇ B rectangular area through decoding.
  • the decoding process usually includes prediction, inverse quantization, and inverse transform to generate a predicted image and residual. The predicted image and residual are superimposed and reconstructed. image.
  • Quadtree A tree-like structure in which a node can be divided into four child nodes.
  • the H265 video coding standard uses a quadtree-based CTU division method: CTU as the root node, each node corresponds to a square area; a node can no longer be divided (in this case, the corresponding area is a CU), or this
  • the node is divided into four next-level nodes, that is, the square area is divided into four square areas of the same size (the length and width are half of the length and width of the area before division), and each area corresponds to a node. As shown in Figure 6 (a).
  • Binary tree A tree structure in which a node can be divided into two child nodes.
  • a node on a binary tree structure may not be divided, or the node may be divided into two nodes at a lower level.
  • Trigeminal tree A tree structure in which a node can be divided into three child nodes.
  • a node on a tri-tree structure may not be divided, or the node may be divided into three nodes at the next level.
  • Video decoding (video decoding): the process of restoring the video stream to a reconstructed image according to specific grammar rules and processing methods.
  • Video encoding The process of compressing an image sequence into a code stream
  • Video encoding The general term for video encoding and video decoding.
  • the Chinese translation is the same as video encoding.
  • VTM New codec reference software developed by JVET.
  • AVS2 Second-generation digital audio and video codec technology standard (AVS)
  • the video coding standard divides a frame of images into non-overlapping coding tree units (CTU).
  • the size of the CTU can be set to 64 ⁇ 64 (the size of the CTU can also be set to other values, such as the increase of the CTU size in the JVET reference software JEM (128 ⁇ 128 or 256 ⁇ 256).
  • the 64 ⁇ 64 CTU contains a rectangular pixel lattice of 64 pixels in each column and each pixel contains a luminance component or/and a chrominance component.
  • the video codec uses the quad-tree (QT)-based CTU division method, which uses the CTU as the root node of the quad-tree.
  • the CTU is recursively divided into several leaves Node (leaf node).
  • a node corresponds to an image area. If the node is not divided, the node is called a leaf node, and its corresponding image area forms a CU; if the node continues to be divided, the image area corresponding to the node is divided into four areas of the same size (which The length and width are each half of the divided area), each area corresponds to a node, you need to determine whether these nodes will be divided.
  • Whether a node is divided is indicated by the split_cu_flag of the division flag bit corresponding to this node in the code stream.
  • the quad-tree level (qtDepth) of the root node is 0, and the quad-tree level of the child node is +1 of the quad-tree level of the parent node.
  • the size and shape of the node in the following refers to the size and shape of the image area corresponding to the node.
  • this leaf node When a node is parsed as a leaf node, this leaf node is a CU, and further parses the coding information corresponding to the CU (including CU prediction mode, transform coefficients and other information, such as the coding_unit() syntax structure in H.265), Then, according to the coding information, the CU is subjected to decoding processing such as prediction, inverse quantization, inverse transform, and loop filtering to generate a reconstructed image corresponding to the CU.
  • the quadtree structure allows the CTU to be divided into a group of CUs of suitable size according to the local characteristics of the image, for example, smooth regions are divided into larger CUs, and texture-rich regions are divided into smaller CUs.
  • a CTU divided into a group of CUs corresponds to a coding tree (coding tree). Which coding tree should be used for CTU is usually determined by the encoder's rate-distortion optimization (RDO) technology.
  • RDO rate-distortion optimization
  • the encoder tries a variety of CTU division methods, each of which corresponds to a rate-distortion cost (RD cost); the encoder compares the RD costs of various tried division methods and finds the division method with the smallest RD cost as the CTU
  • the optimal division method is used for the actual coding of the CTU.
  • the various CTU division methods tried by the encoder need to comply with the division rules specified by the decoder, so that these can be correctly recognized by the decoder.
  • the video coding standard is a block-based coding method.
  • a frame of image needs to be divided into non-overlapping coding tree units (CTU).
  • the size of the CTU can be set to 64 ⁇ 64 (the size of the CTU can also be set to other values, such as (The CTU size in JVET reference software JEM is increased to 128 ⁇ 128 or 256 ⁇ 256).
  • the CTU can be divided into several coding units CU according to the quad-tree (QT) structure.
  • Each CU contains one luma coding block (CB) and two chroma coding blocks (CB) and corresponding syntax elements. (Including information such as the CU's prediction mode and transform coefficients, such as the coding_unit() syntax structure in H.265).
  • the coding unit CU can be further divided into one or more prediction units (Prediction Unit, PU) and transform units (Transform Unit, TU).
  • the prediction unit is the basic unit for performing prediction operations, including intra prediction and inter prediction.
  • the CU determines all PU prediction methods and division methods included in this unit.
  • the transformation unit is the basic unit for transformation and quantization, which is divided on the basis of CU.
  • the division of CU to TU uses quad-tree (QT), called “transformation tree” or residual quadtree (Residual Quad Tree, RQT).
  • QT quad-tree
  • RQT residual quadtree
  • TT Triple Tree
  • BT Binary Tree
  • a CU can be divided into multiple PUs, CU to PU is divided into only one layer, the smallest PU is 4x4. As shown in Figure 7, a 2Nx2N CU can be divided into 8 PU modes. For inter prediction, the optional methods are as shown in FIG. 7. For intra prediction, there are only 2Nx2N or NxN methods.
  • AVS2 proposes a division method of four points (including horizontal four points, vertical four points) and asymmetric partition (AMP).
  • the asymmetric division includes asymmetric horizontal dichotomy and asymmetric vertical dichotomy, as shown in FIG. 8 below, and the horizontal quarter and vertical quarters are shown in FIGS. 8(e) and (f).
  • the size of the current coding block is WxH, that is, the horizontal direction contains W pixels, and the vertical direction contains H pixels.
  • the division method of the CU into multiple TUs is quad-tree (QT), and may also be binary tree, tri-tree tree division, the above-mentioned horizontal quadrant, and vertical quadrant.
  • QT quad-tree
  • Binary tree division includes two ways: horizontal bisection and vertical bisection, and the CU is divided into 2 TUs. As shown in Figure 9.
  • the trigeminal tree division includes horizontal three-point division and vertical three-point division, and divides the CU into three TUs.
  • the level three division divides the current CU level into two Wx (H/4) size TUs and one Wx (H/2) size TU; as shown in FIG. 10.
  • the present invention proposes a method for dividing PB (prediction block) by CU. According to the size of the CU to be divided, the dividing method of dividing PB is determined, without the need to obtain through the code stream, and the complexity of encoding and decoding is reduced.
  • the invention also proposes a method of dividing TB (transform block) by CU.
  • TB transform block
  • one side length of the luminance TB obtained after CU division is 4, the corresponding chromaticity TB size and the CU chromaticity block size the same. In this way, the generation of chroma blocks with side length 2 can be avoided, and the maximum throughput of the decoder can be reduced, which is advantageous for the decoder.
  • the present invention proposes a method for dividing PB (prediction block) by CU. According to the size of the CU to be divided, the division method allowed for dividing PB is determined to reduce the complexity of encoding and decoding.
  • the present invention also proposes a method of dividing TB (transform blocks) by CU, which can determine the division mode of TB according to the division mode of PB. In this way, the complexity of encoding and decoding can be reduced and the encoding and decoding can be improved performance.
  • the invention is applied to a video codec.
  • the video communication system is shown in Fig. 5, 18 is a video encoder and 24 is a video decoder.
  • the invention should be applied to modules 18 and 24.
  • the video data format in this embodiment is YUV4:2:0 format.
  • a similar method can be used for YUV4:2:2 data.
  • Step 1 Analyze the code stream to obtain the prediction method of the current coding unit.
  • the prediction mode of the current coding unit is inter prediction or intra prediction.
  • Step 2 Determine whether the current coding block (or called current coding unit) needs to be divided into at least two luminances PB.
  • the current coding block may be divided into at least one of four equal divisions (including horizontal four divisions, vertical four divisions), and asymmetric division AMP, and may also be other divisions, which are not limited in the present invention .
  • whether the current coding block needs to be divided into at least two brightness PBs can be identified by a syntax element, so whether the current coding block needs to be divided into at least two brightness PBs can be parsed from the code stream.
  • whether the current coding block needs to be divided into at least two luminances PB can also be derived based on the width and height of the current coding unit, and the derivation method needs to satisfy the following conditions:
  • Condition 1 The value of the aspect ratio W/H of the current coding block is between 1/N and N (including 1/N or N), where N is 2, for example.
  • the maximum side length of the current coding block is maxSize (or called the first threshold), for example, maxSize is 64 or 32.
  • the width-to-height ratio of the divided PB is between 1/M and M (including 1/M or M), and M is 8, for example.
  • Condition 4 The width and height of the divided PB are greater than or equal to the threshold minSize (or called the second threshold), where minSize is an integer greater than 1, for example, minSize is 4.
  • Condition 5 The minimum side length of the current coding block is S (or called the third threshold), and the width and height of the divided PB are greater than or equal to K (or called the fourth threshold), for example, S is 16, K Is 4.
  • step 3 to step 6 are performed.
  • Step 3 Determine the brightness PB division method of the current coding block.
  • the information of the brightness PB division mode of the current coding block is usually transmitted in the code stream, and the brightness PB division mode of the current coding block can be obtained by parsing the corresponding syntax element in the code stream.
  • the brightness PB division mode allowed by the current coding block is determined by the width and height of the current coding block and/or the width and height of the divided brightness PB.
  • the determination method may include One of the following methods.
  • Method 1 When the width and height of the current coding block are less than or equal to X, quadrant and AMP division can be used, where X is an integer greater than 16, for example, X is 32 or 64.
  • Method 2 When the width and height of the current coding block are equal to Y, only four equal divisions are used, and AMP division cannot be used, where Y is an integer greater than 16, for example, Y is 64.
  • Method 3 When the length of the side of the current coding block to be divided is equal to A, and the length of the non-divided side is equal to B, the division of the side to be divided can only be divided into four equal parts, and AMP cannot be used.
  • a and B are greater than An integer of 4, for example, A is 64, B is 32, and if A is 32 and B is 32, the edge to be divided is the width of the current coding block, then the division of the edge to be divided refers to the vertical quadrant, vertical Straight 1:3 asymmetric division, vertical 3:1 asymmetric division; the edge to be divided is the height of the current coding block, then the division of the edge to be divided refers to horizontal quadrant, horizontal 1:3 asymmetric division, Level 3:1 asymmetric division.
  • Method 4 When the length of the side of the current coding block to be divided is equal to C, and the length of the non-divided side is equal to D, the division of the side to be divided does not use quartile and AMP.
  • C and D are integers greater than 4, for example, C is 32 and D is 64, and for example, C is 32 and D is 32.
  • the to-be-divided side of the above coding block is the side perpendicular to the dividing direction: when the dividing mode is vertical quartering and asymmetric vertical bisection, the side to be divided is the width of the coding block; when the dividing mode is horizontal quartering, non- When the symmetric horizontal dichotomy, the side to be divided is the height of the coding block.
  • the non-division side of the coding block is the side parallel to the division direction: when the division mode is vertical quartering and asymmetric vertical bisection, the non-division side is the height of the coding block; when the division mode is horizontal quartering, non-division In symmetric horizontal dichotomy, the side to be divided is the width of the coding block.
  • Step 4 Divide the current coding block according to the corresponding division method to obtain the luma PB and the chroma PB.
  • the current coding block uses intra prediction, its luma block is divided according to the luma PB division mode of the current coding block to obtain each luma PB; the chroma block of the current coding block is not divided, corresponding to one chroma PB.
  • the current coding block uses inter prediction, one of the following methods can be used:
  • Method 1 The chroma block and the luma block of the current coding block are divided according to the luma PB division mode of the current coding block, to obtain each luma PB and chroma PB.
  • Method 2 When the luma block is divided into at least 2 luma PBs, and at least one side of the divided luma PB has a side length of 4, the chroma block is not divided and becomes a chroma PB; otherwise, the current coding block The chroma block and the luma block are divided according to the luma PB division method of the current coding block to obtain each luma PB and chroma PB.
  • the motion information of the chroma component is the motion information of the luminance PB at the center position of the current coding block.
  • the center position refers to: if the size of the current coding block is WxH, the coordinates of the center position relative to the upper left vertex of the current coding block are (W/2, H/2).
  • Step 5 Determine the division method of the luminance TB and chrominance TB of the current coding block to obtain the size of each TB.
  • intra prediction When intra prediction is used for the current coding block, one of the following methods can be used to obtain the TB.
  • the brightness PB is divided into a vertical quadrant or an asymmetric vertical dichotomy, its brightness block is divided into four brightness TBs according to the vertical quadrant.
  • the chroma block is not divided and becomes a chroma TB.
  • the brightness block can be divided into 4 brightness TBs according to the vertical quartering mode or directly become 1 brightness TB without division;
  • the luminance block may be divided into 4 TBs or not divided into 1 TB according to the horizontal quartiles. Whether the luma block is divided into 4 TBs or 1 TB can be determined by parsing the syntax elements in the code stream.
  • the TB division of the chroma block can be in one of the following ways:
  • Method 1 The TB division method of the chroma block is the same as the TB division method of the luma block.
  • Method 2 The chroma block is not divided and becomes a chroma TB.
  • Method 3 When the luma block is divided into 4 luma TB in a quartile manner and the side length of one side of the luma TB is E (for example, 4), the chroma block is not divided and becomes a chroma TB
  • Step 6 Obtain the prediction information of each brightness PB, and obtain the residual information of each brightness TB.
  • the prediction information of the luminance PB and the residual information of the luminance TB can be obtained by parsing the corresponding syntax elements in the code stream, or can also be obtained by derivation.
  • the prediction information of the luminance PB includes: prediction mode (indicating intra prediction or inter prediction mode), intra prediction mode, motion information, and the like.
  • the intra prediction mode of the luma block can be one of the plane mode (Planar Mode), DC mode (DC Mode), and angle mode (Angular Mode);
  • the motion information can include the prediction direction (forward, backward, or bidirectional), reference frame Index (reference), motion vector (motion vector) and other information.
  • the residual information of the luminance TB includes: coded block flag (coded block flag, cbf), transform coefficient, transform type (eg, DCT-2, DST-7, DCT-8), etc.
  • Step 7 Obtain the prediction information of each chroma PB, and obtain the residual information of the chroma TB.
  • the prediction information of the chroma PB and the residual information of the chroma TB can be obtained by parsing the corresponding syntax elements in the code stream, or can also be obtained by derivation.
  • the intra prediction mode of the chroma PB may be one of a DC mode, a planar mode, an angle mode, and a linear model mode.
  • the transform type of chroma TB can be DCT-2 transform by default.
  • the inter prediction processing or the intra prediction processing can be performed on each luminance PB according to the prediction mode corresponding to each luminance PB, to obtain an inter prediction image of each luminance PB or Intra prediction image. Then, based on the residual information of each brightness TB, the transform coefficient is subjected to inverse quantization and inverse transform processing to obtain a residual image of each brightness TB. The predicted image of each luminance PB and the residual image of each luminance TB are added to generate a reconstructed image of the luminance block.
  • the inter prediction process or the intra prediction process can be performed on the chroma PB according to the prediction mode of the chroma PB, to obtain an inter prediction image of the chroma PB or Intra prediction image.
  • the transform coefficient is subjected to inverse quantization and inverse transform processing to obtain a residual image.
  • the predicted image of each chroma PB and the residual image of each chroma TB are added to produce a reconstructed image of chroma blocks.
  • the optional PB and TB division methods of the current CU are determined according to the width and height of the current CU, to avoid the PB size exceeding the size of the hardware pipeline unit (such as 32x32).
  • the chroma TB is limited to not divided to avoid the generation of a chroma TB with a side length of 2.
  • FIG. 12 is a schematic flowchart of a method 1200 for processing an encoding block according to an embodiment of the present application.
  • the method 1200 for processing an encoding block shown in FIG. 12 may be performed by the encoder 20 shown in FIG. 2 above, or may also be performed by the decoder 30 shown in FIG. 3 above.
  • the method 1200 shown in FIG. 12 includes steps 1210, 1220, and 1230, and these steps are described in detail below.
  • S1210 Obtain a prediction mode of the current coding unit, and/or obtain a prediction division mode of the current coding unit, where the current coding unit includes a luma coding block and a chroma coding block, and the prediction division mode is to divide the current
  • the coding unit is divided into prediction blocks or prediction units.
  • the prediction mode may include an intra prediction mode and an inter prediction mode
  • the prediction division mode may include quadrant division and asymmetric division (AMP).
  • asymmetric division may include vertical 3:1 asymmetric division, vertical 1:3 asymmetric division, horizontal 1:3 asymmetric division, and horizontal 3:1 asymmetric division.
  • Four equal divisions may be It includes a vertical quadrant and a horizontal quadrant, where the size of the current coding block is W*H, that is, the horizontal direction contains W pixels, and the vertical direction contains H pixels.
  • FIG. 13 is only an example and not a limitation.
  • the prediction division manner of the current coding block described in this application may also include other division manners, which is not limited in this embodiment of the application.
  • the acquiring the prediction mode of the current coding unit (CU) may include: acquiring the prediction mode.
  • the obtaining the prediction mode of the current coding unit may include: parsing or deriving the prediction mode from a code stream, and the prediction mode includes an intra prediction mode and an inter prediction mode.
  • the obtaining the prediction division mode of the current coding unit may include: obtaining the prediction division mode.
  • the obtaining the prediction mode of the current coding unit may include: determining a candidate prediction division method allowed by the current coding unit according to the size of the current coding unit; The prediction division mode is determined from the candidate prediction division modes allowed to be used.
  • determining the prediction division mode from the allowed candidate prediction division modes may refer to: parsing the indicator indicating the prediction division mode from the code stream, and according to the prediction division mode identifier, from all The prediction division method is determined among the allowed candidate prediction division methods.
  • the code stream (video data) format may be YUV4:2:0 format or YUV4:2:2 format, or may be other formats, which is not limited in this application.
  • the acquiring the prediction division mode of the current coding unit may also include: determining the prediction division mode of the current coding unit according to the size of the current coding unit.
  • the prediction division mode can be determined, therefore, the video coding can be reduced.
  • the complexity of decoding improves coding and decoding efficiency.
  • the acquiring the prediction division mode of the current coding unit may further include: determining the prediction division mode of the current coding unit according to the prediction mode.
  • the prediction division mode can be determined, therefore, the complexity of video encoding and decoding can be reduced Degree, improve the efficiency of codec.
  • the above determination of the prediction division mode of the current coding unit according to the size of the current coding unit may be implemented in one of the following ways:
  • the prediction division mode of the current coding unit is quadrant division or asymmetric division, where, M can be an integer greater than 16. For example, M is 32 or 64.
  • the prediction division mode of the current coding unit is a quadrant division, where N may be an integer greater than 16. For example, N is 64.
  • the prediction division of the current coding unit is divided into four equal parts.
  • the length of the side to be divided is 64, and the length of the side to be not divided is 32; or, the length of the side to be divided is 32, and the length of the side to be not divided is 32.
  • the side to be divided is a side perpendicular to the dividing direction of the current coding unit
  • the non-to-be-divided side is a side parallel to the dividing direction of the current coding unit.
  • the edges to be divided in a, b, and e in FIG. 13 are the width of the coding unit, and the edges to be divided are the height of the coding unit; the edges in c, d, and f in FIG. 13 are the coding The height of the unit, and the width of the coding unit is the side not to be divided.
  • the prediction division of the current coding unit is not divided into four divisions or asymmetric division. It should be noted that, if the prediction division mode of the current coding unit includes quadrant division or asymmetric division, then the current coding unit is no longer divided.
  • the length of the side to be divided is 32, and the length of the side to be not divided is 64; or, the length of the side to be divided is 32, and the length of the side to be not divided is 32.
  • the prediction division mode of the current coding unit is asymmetric division, and the preset first threshold is greater than or equal to 16.
  • An integer, wherein the first threshold may be an integer greater than or equal to 16.
  • the first threshold is 16; or, the first threshold is 32.
  • the edge to be divided of the current coding unit is an edge perpendicular to the dividing direction.
  • the edge to be divided is the width of the current coding unit; when the prediction division method is horizontal quartering and asymmetric horizontal bisection, the edge to be divided is The height of the current coding unit.
  • the to-be-divided side of the current coding unit is the side parallel to the dividing direction.
  • the non-dividing edge is the height of the current coding unit
  • the side to be divided is The width of the current coding unit
  • the prediction division manner of the current coding unit may also be determined by other methods, which is not limited in this embodiment of the application.
  • the method 1200 may further include S1201.
  • S1201 Determine whether to allow the current coding unit to be divided to obtain a prediction block.
  • prediction block PB
  • PB prediction block
  • the current coding unit it may be determined whether the current coding unit is allowed to be divided to obtain a prediction block:
  • the current coding unit when the size of the current coding unit satisfies at least one of the following conditions, it may be determined that the current coding unit is allowed to be divided to obtain a prediction block:
  • the ratio of the width and height of the current coding unit is less than P, where;
  • the maximum side length of the current coding unit is equal to the preset first threshold
  • the ratio of the width and height of the prediction block obtained by the current coding unit being pre-divided is between 1/Q and Q;
  • the width and height of the prediction block obtained by the current coding unit being pre-divided are greater than or equal to a preset second threshold
  • the minimum side length of the current coding block is equal to the preset third threshold, and the width and height of the prediction block obtained by the current coding unit being pre-divided are greater than or equal to the preset fourth threshold.
  • Q and P are positive integers, and the second threshold may be an integer greater than 1.
  • Q may be 8
  • the first threshold may be 64 or 32
  • the second threshold may be 4
  • the above-mentioned pre-division refers to estimating a prediction block that may be obtained after the current coding unit is divided in advance, rather than actually dividing the current coding unit.
  • the current coding unit when the size of the current coding unit does not satisfy any of the above conditions, it may be determined that the current coding unit is not allowed to be divided to obtain a prediction block.
  • the size of the current coding unit it can be determined whether the current coding unit is allowed to be divided to obtain a prediction block. Therefore, the complexity of video encoding and decoding can be reduced and the encoding and decoding efficiency can be improved. .
  • the method for obtaining the prediction division of the current coding unit may be performed only when it is determined that the current coding unit is allowed to be divided to obtain a prediction block.
  • the syntax element may be parsed from the code stream, and the syntax element may be used to determine whether to allow the current coding unit to be divided to obtain the prediction block.
  • the prediction block of the current coding unit may be obtained according to the prediction division mode and/or the prediction mode.
  • the prediction coding method may be used to divide the luma coding block to obtain a luma prediction block, without dividing the chroma coding block, and dividing all
  • the chroma coding block is used as a chroma prediction block.
  • the current coding unit may not be divided, and the current coding unit may be used as the prediction unit.
  • the current coding unit is not divided, which can avoid the generation of an encoding block that is too small in size, and can improve codec efficiency.
  • the current coding unit may be divided in any of the following ways:
  • the chroma coding block is not divided, and the chroma coding block is used as a chroma prediction block; otherwise, the prediction coding method is used to divide the luma coding block to obtain a luma prediction block , Using the prediction division method to divide the chroma coding block to obtain a chroma prediction block.
  • the motion information of the chroma component may be the motion information of the luma coding block at the center position of the current coding unit.
  • the center position may refer to: if the size of the current coding unit is W*H, the coordinates of the center position relative to the upper left vertex of the current coding unit are (W/2, H/2).
  • the transform block of the current coding unit is obtained directly according to the prediction division method and/or the prediction mode (no need to parse the code stream or only a small amount of information in the code stream), so , Can reduce the complexity of video encoding and decoding, and improve encoding and decoding efficiency.
  • S1220 Obtain the transform block of the current coding unit according to the prediction division mode and/or the prediction mode.
  • the transform block (TB) of the current coding unit may be obtained according to the prediction division mode and the prediction mode, or the current coding unit may also be obtained according to the prediction division mode Transform block of the current coding unit, or the transform block of the current coding unit can be obtained according to the prediction mode.
  • the current coding unit can be divided into transform blocks Therefore, the complexity of video encoding and decoding can be reduced, and the encoding and decoding efficiency can be improved.
  • obtaining the transform block of the current coding unit according to the prediction division mode and/or the prediction mode may include: according to the prediction division mode and/or the prediction mode, converting the The current coding unit is divided into transform blocks.
  • the vertical quartering pair can be used
  • the luma coding block is divided to obtain a luma transform block, the chroma coding block is not divided, and the chroma coding block is used as a chroma transform block.
  • the horizontal quadrant may be used to encode the luminance
  • the block is divided to obtain a luma transformation block, the chroma coding block is not divided, and the chroma coding block is used as a chroma conversion block.
  • the current coding unit may not be divided, and the current coding unit may be used as a transformation unit.
  • the luma coding block may not be divided and the luma transform block may be directly obtained.
  • the chroma coding block may not be divided and the chroma transform block may be directly obtained.
  • the current coding unit may be divided into transform blocks in any of the following ways:
  • the vertical quartile may be used for the luminance
  • the coding block is divided to obtain a luminance transformation block.
  • the chroma coding block may not be divided, and the chroma coding block may be used as a chroma transformation block, or the chroma coding block may also be divided using a vertical quadrant Or, the chroma coding block may also be pre-divided according to the vertical quadrant, and when the side length of one side of the obtained chroma transform block is 4, the chroma coding block may not be divided, Let the chroma-encoded block be the chroma transform block.
  • the horizontal quadrant may be used to perform the luma coding block Divide and get the brightness transform block.
  • the chroma coding block may not be divided, and the chroma coding block may be used as a chroma transformation block, or the chroma coding block may also be divided using a horizontal quadrant, Alternatively, when the chroma coding block is pre-divided according to a horizontal quadrant, and when the length of one side of the obtained chroma transform block is 4, the chroma coding block is not divided, and the color The degree coding block is used as the chrominance conversion block.
  • the current coding unit may not be divided, and the current coding unit may be used as a transformation unit.
  • the luma coding block may not be divided and the luma transform block may be directly obtained.
  • the chroma coding block may not be divided and the chroma transform block may be directly obtained.
  • the transform block of the current coding unit is obtained directly according to the prediction division method and/or the prediction mode (no need to parse the code stream or only a small amount of information in the code stream), so , Can reduce the complexity of video encoding and decoding, and improve encoding and decoding efficiency.
  • S1230 Generate a reconstructed image block of the current coding unit according to the transform block.
  • the reconstructed image block of the current coding unit may be generated according to the prediction block and the transform block.
  • the prediction information of the luma prediction block and the residual information of the luma transform block may be parsed or derived from the code stream.
  • the prediction information of the luminance prediction block may include: prediction mode, intra prediction mode, motion information, etc.
  • the prediction mode can indicate an intra prediction mode or an inter prediction mode.
  • the intra prediction mode can be a planar mode, a DC mode, or an angular mode; motion information can include a prediction direction (forward direction) , Backward or bidirectional), reference frame index (reference index) or motion vector (motion vector) and other information.
  • the residual information of the brightness transform block may include: coded block flags (coded block flag, cbf), transform coefficients, transform types (eg, DCT-2, DST-7, DCT-8), etc.
  • coded block flags coded block flag, cbf
  • transform coefficients transform types (eg, DCT-2, DST-7, DCT-8), etc.
  • the inter prediction process or the intra prediction process can be performed on each luma prediction block according to the prediction mode corresponding to each luma prediction block to obtain each luma prediction block Inter prediction image or intra prediction image.
  • the transform coefficients are subjected to inverse quantization and inverse transform processing to obtain the residual image of each brightness transform block.
  • the predicted image of each luminance prediction block and the residual image of each luminance transformation block are added to produce a reconstructed image of the luminance block.
  • the prediction information of the chroma prediction block and the residual information of the chroma transform block can be parsed or derived from the code stream.
  • the intra prediction mode of the chroma prediction block may be a DC mode, a planar mode, an angle mode or a linear model (linear model) mode.
  • the transform type of the chroma transform block may be DCT-2 transform.
  • each chroma prediction block and the residual information of the chroma transform block After obtaining the prediction information of each chroma prediction block and the residual information of the chroma transform block, you can perform inter prediction processing or intra prediction processing on the chroma prediction block according to the prediction mode corresponding to each chroma prediction block to obtain the chroma prediction Inter prediction image or intra prediction image of a block. Then, according to the residual information of the chroma transform block, the transform coefficient is subjected to inverse quantization and inverse transform processing to obtain a residual image. The predicted image of each chroma prediction block and the residual image of each chroma transform block are added to produce a reconstructed image of the chroma block.
  • a reconstructed image block of the current coding unit may be generated.
  • the transform block of the current coding unit can be obtained, At this time, generating the reconstructed image block of the current coding unit according to the transform block can reduce the complexity of video encoding and decoding, and improve the encoding and decoding efficiency.
  • the image reconstruction device 5000 shown in FIG. 14 includes:
  • the obtaining unit 5001 is configured to obtain the prediction mode of the current coding unit, and/or to obtain the prediction division mode of the current coding unit.
  • the current coding unit includes a luma coding block and a chroma coding block, and the prediction division mode is A manner of dividing the current coding unit into prediction blocks or prediction units;
  • the processing unit 5002 is configured to obtain a transform block of the current coding unit according to the prediction division mode and/or the prediction mode;
  • the reconstruction unit 5003 is configured to generate a reconstructed image block of the current coding unit according to the transform block.
  • the transform block of the current coding unit can be obtained, At this time, generating the reconstructed image block of the current coding unit according to the transform block can reduce the complexity of video encoding and decoding, and improve the encoding and decoding efficiency.
  • the processing unit 5002 is specifically configured to divide the current coding unit into transform blocks according to the prediction division mode and/or the prediction mode.
  • the acquiring unit 5001 is specifically configured to parse or derive the prediction mode from a code stream, and the prediction mode includes an intra prediction mode and an inter prediction mode.
  • the obtaining unit 5001 is specifically configured to: according to the size of the current coding unit, determine a candidate prediction division mode allowed by the current coding unit; determine the location from the allowed candidate prediction division mode Describe the prediction division method.
  • the obtaining unit 5001 is specifically configured to determine the prediction division manner of the current coding unit according to the size of the current coding unit.
  • the processing unit 5002 is further configured to: when the prediction mode is an intra prediction mode, use the prediction division method to divide the luma coding block to obtain a luma prediction block.
  • the chroma coding block is divided, and the chroma coding block is used as a chroma prediction block.
  • the processing unit 5002 is further configured to: when the prediction mode is an inter prediction mode, do not divide the current coding unit, and use the current coding unit as the prediction unit.
  • the processing unit 5002 is further configured to: when the prediction mode is an inter prediction mode, divide the current coding unit in any of the following ways: use the prediction division method to divide Dividing the luma coding block to obtain a luma prediction block, using the prediction division method to divide the chroma coding block to obtain a chroma prediction block; or using the prediction division method to divide the luma coding block, Obtaining a luma prediction block, and when there are two luma prediction blocks and at least one side of at least one luma prediction block of the two luma prediction blocks has a length of 4, the chroma coding block is not divided, The chroma coding block is used as a chroma prediction block.
  • the processing unit 5002 is specifically configured to: when the prediction mode is an intra prediction mode, and the prediction division mode of the luminance coding block is a vertical quadrant or an asymmetric vertical bisection Next, divide the luma coded block by using a vertical quadrant to obtain a luma transform block, do not divide the chroma coded block, and use the chroma coded block as a chroma transform block; or in the prediction mode Is an intra prediction mode, and when the prediction division method of the luma coding block is horizontal quadrant or asymmetric horizontal bisection, the luma coding block is divided using horizontal quadrant to obtain a luma transform block , The chroma coding block is not divided, and the chroma coding block is used as a chroma transform block.
  • the processing unit 5002 is specifically configured to: when the prediction mode is an inter prediction mode, do not divide the current coding unit, and use the current coding unit as a transformation unit.
  • the processing unit 5002 is further configured to: when the size of the current coding unit meets at least one of the following conditions, determine whether to allow division of the current coding unit to obtain a prediction block: the current coding The ratio of the width and height of the unit is less than P, where P is a positive integer; or the maximum side length of the current coding unit is equal to a preset threshold; when it is determined that the current coding unit is allowed to be divided to obtain a prediction block The next step is to execute the method of obtaining the prediction division of the current coding unit.
  • the image reconstruction device 5000 may be either an encoding device or a decoding device.
  • the acquisition unit 5001 in the image reconstruction device 5000 may correspond to the prediction processing unit 260 in the encoder 20 shown in FIG. 2, and the processing unit 5002 may correspond to the one shown in FIG. 2
  • the prediction processing unit 260, the transform processing unit 206, or the inverse transform processing unit 212 in the encoder 20, or a unit for performing fast division not shown in FIG. 2, the reconstruction unit 5003 may correspond to that shown in FIG. 2.
  • the acquisition unit 5001 in the image reconstruction apparatus 5000 may correspond to the prediction processing unit 360 or the entropy decoding unit 304 in the decoder 30 shown in FIG. 3, and the processing unit 5002 may correspond to The prediction processing unit 360, the inverse transform processing unit 312 in the decoder 30 shown in FIG. 3, or a unit for performing fast division not shown in FIG. 3, the reconstruction unit 5003 may correspond to the decoder shown in FIG. At least one of the inverse quantization unit 310, the inverse transform processing unit 312, and the reconstruction unit 314 in 30.
  • the acquisition unit 5001, the processing unit 5002, and the reconstruction unit 5003 in the image reconstruction device 5000 may correspond to the encoding/decoding module 470 in the processor 430 shown in FIG. 4,
  • the encoding/decoding module 470 can perform various steps performed by the image reconstruction device 5000.
  • the acquisition unit 5001, the processing unit 5002, and the reconstruction unit 5003 in the image reconstruction device 5000 may correspond to the encoding/decoding module 470 in the processor 430 shown in FIG. 4,
  • the encoding/decoding module 470 can perform various steps performed by the image reconstruction device 5000.
  • the image reconstruction device 5000 described above can be implemented in a variety of devices or equipment, including a wireless handset, an integrated circuit (IC), or a set of ICs (eg, chipsets).
  • IC integrated circuit
  • Various components, modules or units are described in this application to emphasize the functional aspects of the device for performing the disclosed technology, but do not necessarily need to be implemented by different hardware units.
  • various units may be combined in a codec hardware unit in combination with suitable software and/or firmware, or by interoperating hardware units (including one or more processors as described above) Provided, this is not limited in the embodiments of the present application.
  • the above-mentioned image reconstruction device 5000 may also be called a codec device or a codec, and the image reconstruction device 5000 can realize encoding or decoding of a video image.
  • the image reconstruction device 6000 shown in FIG. 15 includes:
  • the memory 6001 is used to store programs
  • the processor 6002 is used to execute the program stored in the memory 6001. When the program stored in the memory 6001 is executed, the processor 6002 is used to:
  • the current coding unit includes a luma coding block and a chroma coding block, and the prediction division mode is to divide the current coding unit The method of dividing into prediction blocks or prediction units;
  • a reconstructed image block of the current coding unit is generated.
  • the acquisition unit 5001, the processing unit 5002, and the reconstruction unit 5003 in the image reconstruction device 5000 may correspond to the processor 6002 in the image reconstruction device 6000, and the processor 6002 can implement the acquisition unit 5001 in the image reconstruction device 5000. 5002 and the function of the reconstruction unit 5003.
  • the memory 6001 in the image reconstruction device 6000 described above may correspond to the memory 530 in FIG. 5, and the processor 6002 may correspond to the processor 510 shown in FIG. 5.
  • the image reconstruction device 6000 may implement the image reconstruction method in FIG. 12 described above. In various embodiments, the image reconstruction device 6000 can also perform various steps performed by the image reconstruction device 5000.
  • the image reconstruction device 6000 may be either an encoding device or a decoding device.
  • the above-mentioned image reconstruction device 6000 may also be called a codec device or a codec, and the image reconstruction device 6000 can realize encoding or decoding of a video image.
  • the processor in the embodiments of the present application may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSPs), and application specific integrated circuits (application specific integrated circuit, ASIC), ready-made programmable gate array (field programmable gate array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc.
  • the general-purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
  • the memory in the embodiments of the present application may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory.
  • the non-volatile memory may be read-only memory (read-only memory, ROM), programmable read-only memory (programmable ROM, PROM), erasable programmable read-only memory (erasable PROM, EPROM), electronically Erasable programmable read only memory (electrically EPROM, EEPROM) or flash memory.
  • the volatile memory may be a random access memory (random access memory, RAM), which is used as an external cache.
  • random access memory random access memory
  • static random access memory static random access memory
  • DRAM dynamic random access memory
  • DRAM synchronous dynamic random access Access memory
  • SDRAM double data rate synchronous dynamic random access memory
  • double data Srate double data Srate
  • DDR SDRAM enhanced synchronous dynamic random access memory
  • ESDRAM synchronous connection dynamic random access memory Take memory (synchlink DRAM, SLDRAM) and direct memory bus random access memory (direct rambus RAM, DR RAM).
  • the above embodiments may be implemented in whole or in part by software, hardware, firmware, or any other combination.
  • the above-described embodiments may be implemented in whole or in part in the form of computer program products.
  • the computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the processes or functions according to the embodiments of the present application are generated in whole or in part.
  • the computer may be a general-purpose computer, a dedicated computer, a computer network, or other programmable devices.
  • the computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be from a website site, computer, server or data center Transmit to another website, computer, server or data center by wired (such as infrared, wireless, microwave, etc.).
  • the computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that contains one or more collections of available media.
  • the usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium.
  • the semiconductor medium may be a solid state drive.
  • the unidirectional communication link from the access network to the terminal is defined as a downlink, and the data transmitted on the downlink is the downlink data.
  • the transmission direction of the downlink data is called the downlink direction; and the terminal to the access network
  • the unidirectional communication link is the uplink, and the data transmitted on the uplink is the uplink data.
  • the transmission direction of the uplink data is called the uplink direction.
  • the resources described in the embodiments of the present application may also be referred to as transmission resources, including one or more of time-domain resources, frequency-domain resources, and code channel resources, and may be used to carry data in an uplink communication process or a downlink communication process Or signaling.
  • B corresponding to A indicates that B is associated with A, and B can be determined according to A.
  • determining B based on A does not mean determining B based on A alone, and B may also be determined based on A and/or other information.
  • Multiple appearing in the embodiments of the present application refers to two or more.
  • connection appearing in the embodiment of the present application refers to various connection methods such as direct connection or indirect connection, so as to realize communication between devices, and the embodiment of the present application does not make any limitation on this.
  • “transmit/transmission” in the embodiments of the present application refers to two-way transmission, including sending and/or receiving operations.
  • “transmission” in the embodiments of the present application includes sending data, receiving data, or sending data and receiving data.
  • the data transmission here includes uplink and/or downlink data transmission.
  • the data may include channels and/or signals, uplink data transmission is uplink channel and/or uplink signal transmission, and downlink data transmission is downlink channel and/or downlink signal transmission.
  • the service (service) appearing in the embodiment of the present application refers to a communication service obtained by the terminal from the network side, including a control plane service and/or a data plane service, such as a voice service and a data traffic service.
  • the transmission or reception of services includes the transmission or reception of service-related data (data) or signaling (signaling).
  • Network and “system” appearing in the embodiments of the present application express the same concept, and the communication system is a communication network.
  • Computer readable media may include computer readable storage media, which corresponds to tangible media, such as data storage media, or communication media including any medium that facilitates transfer of a computer program from one place to another (eg, according to a communication protocol).
  • computer-readable media may generally correspond to (1) non-transitory tangible computer-readable storage media, or (2) communication media, such as signals or carrier waves.
  • Data storage media may be any available media that can be accessed by one or more computers or one or more processors to retrieve instructions, code and/or data structures for implementation of the techniques described in this application.
  • the computer program product may include a computer-readable medium.
  • Such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM, or other optical disk storage devices, magnetic disk storage devices, or other magnetic storage devices, flash memory, or may be used to store instructions or data structures
  • coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology such as infrared, radio, and microwave are used to transmit instructions from a website, server, or other remote source
  • coaxial cable Wire, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of media.
  • the computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other temporary media, but are actually directed to non-transitory tangible storage media.
  • magnetic disks and optical discs include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), and Blu-ray discs, where magnetic discs typically reproduce data magnetically, while optical discs reproduce optically using lasers data. Combinations of the above should also be included in the scope of computer-readable media.
  • DSPs digital signal processors
  • ASICs application specific integrated circuits
  • FPGAs field programmable logic arrays
  • processors may refer to any of the foregoing structure or any other structure suitable for implementation of the techniques described herein.
  • the functions described in 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 in combination Into the combined codec.
  • the techniques can be fully implemented in one or more circuits or logic elements.
  • the technology of the present application can be implemented in a variety of devices or equipment, including wireless handsets, integrated circuits (ICs), or a set of ICs (eg, chipsets).
  • ICs integrated circuits
  • a set of ICs eg, chipsets
  • Various components, modules or units are described in this application to emphasize the functional aspects of the device for performing the disclosed technology, but do not necessarily need to be implemented by different hardware units.
  • various units may be combined in a codec hardware unit in combination with suitable software and/or firmware, or by interoperating hardware units (including one or more processors as described above) provide.

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Abstract

本申请实施例公开了视频图像的图像重建方法和装置。其中，该图像重建方法包括：获取当前编码单元的预测模式，和/或，获取所述当前编码单元的预测划分方式，所述当前编码单元包括亮度编码块和色度编码块，所述预测划分方式为将所述当前编码单元划分成预测块或预测单元的方式；根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块；根据所述变换块，产生所述当前编码单元的重构图像块。本申请实施例的方法能够提高视频编解码效率。

Description

图像重建方法和装置
本申请要求于2018年12月15日提交中国专利局、申请号为201811539678.1、申请名称为“视频编码器、视频解码器及相应方法”的中国专利申请，以及于2018年12月24日提交中国专利局、申请号为201811585506.8、申请名称为“视频编码器、视频解码器及相应方法”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及视频编解码技术领域，并且更具体地，涉及一种图像重建方法和装置。
背景技术
数字视频能力可并入到多种多样的装置中，包含数字电视、数字直播系统、无线广播系统、个人数字助理(personal digital assistant，PDA)、膝上型或桌上型计算机、平板计算机、电子图书阅读器、数码相机、数字记录装置、数字媒体播放器、视频游戏装置、视频游戏控制台、蜂窝式或卫星无线电电话(所谓的“智能电话”)、视频电话会议装置、视频流式传输装置及其类似者。数字视频装置实施视频压缩技术，例如，在由MPEG-2、MPEG-4、ITU-T H.263、ITU-T H.264/MPEG-4第10部分高级视频编码(AVC)定义的标准、视频编码标准H.265/高效视频编码(high efficiency video coding，HEVC)标准以及此类标准的扩展中所描述的视频压缩技术。视频装置可通过实施此类视频压缩技术来更有效率地发射、接收、编码、解码和/或存储数字视频信息。
视频压缩技术执行空间(图像内)预测和/或时间(图像间)预测以减少或去除视频序列中固有的冗余。对于基于块的视频编码，视频条带(即，视频帧或视频帧的一部分)可分割成若干图像块，所述图像块也可被称作树块、编码单元(CU)和/或编码节点。使用关于同一图像中的相邻块中的参考样本的空间预测来编码图像的待帧内编码(I)条带中的图像块。图像的待帧间编码(P或B)条带中的图像块可使用相对于同一图像中的相邻块中的参考样本的空间预测或相对于其它参考图像中的参考样本的时间预测。图像可被称作帧，且参考图像可被称作参考帧。
随着互联网和移动通信技术的快速发展，数字视频正朝着高清晰度、高帧率、高压缩率的方向迈进，视频的格式从720P发展到1080P，甚至出现了4Kx2K、8Kx4K的超高清晰数字视频。这些高清晰度的视频大大增加了视频编解码的复杂度，相应地，对视频进行压缩和解压缩所花费的时间也随之增加。
因此，如何提高视频编解码效率成为一个亟需解决的问题。
发明内容
本申请实施例提供一种视频图像的编解码方法、装置及相应的编码器和解码器，一定程度上提高提高编解码性能。
第一方面，本申请实施例提供了一种视频解码方法，包括：
获取当前编码单元(coding unit)的尺寸信息；
根据所述当前编码单元的尺寸信息，将所述当前编码单元的亮度块划分为至少两个亮度预测块；
对所述至少两个亮度预测块的预测信息进行预测，得到所述当前编码单元的预测信息；
所述根据所述当前编码单元的尺寸信息，将所述当前编码单元的亮度块划分为至少两个亮度预测块包括：
在所述当前编码单元的宽和高均小于或等于X时，使用第一划分方式对所述当前编码单元的亮度块进行划分，X为正整数，所述第一划分方式包括四等分或者非对称划分；或者，
在所述当前编码单元的宽和高均等于Y时，使用四等分的划分方式对所述当前编码单元的亮度块进行划分，Y为正整数；或者，
在所述当前编码单元的待划分边的边长等于A，且所述当前编码单元的非划分边的边长等于B时，使用四等分的划分方式对所述当前编码单元的亮度块进行划分，其中所述四等分的划分方式的划分方向垂直于所述当前编码单元的待划分边，A和B为正整数，所述当前编码单元的待划分边的边长为在所述亮度块的划分方式为数值四等分或者数值非对称划分时所述当前编码单元的宽，所述当前编码单元的非划分边的边长为在所述亮度块的划分方式为竖直四等分或者竖直非对称划分时所述当前编码单元的高；或者，所述当前编码单元的待划分边的边长为在所述亮度块的划分方式为水平四等分或者水平非对称划分时所述当前编码单元的高，所述当前编码单元的非划分边的边长为在所述亮度块的划分方式为水平四等分或者水平非对称划分时所述当前编码单元的宽；或者，
在所述当前编码单元的待划分边的边长等于C，且所述当前编码单元的非划分边的边长等于D时，使用第二划分方式对所述当前编码单元的亮度块进行划分，所述第二划分方式不包括四等分和非对称划分，所述第二划分方式的划分方向垂直于所述当前编码单元的待划分边，C和D为正整数；或者，
在所述当前编码单元的待划分边的边长小于T时，使用第三划分方式对所述当前编码单元的亮度块进行划分，其中所述第三划分方式的划分方向垂直于所述当前编码单元的待划分边，其中T为正数，所述第三划分方式包括非对称划分，不包括四等分划分。
第二方面，本申请实施例提供了一种视频解码方法，包括：
获取当前编码单元(coding unit)的尺寸信息；
根据所述当前编码单元的尺寸信息，判断所述当前编码单元是否满足将所述当前编码单元的亮度块划分为至少两个亮度预测块的条件，所述条件包括以下条件中的至少一项：
条件1：所述当前编码单元的宽高比的值大于或者等于1/N，并且小于或者等于N，N为正数；
条件2：所述当前编码单元的最大边长为第一阈值，所述第一阈值为正数；
条件3：如果将所述当前编码单元的亮度块划分为至少两个亮度预测块，则划分得到的亮度预测块的宽高比值大于或者等于1/M，并且小于或者等于M，M为正数，所述划分得到的亮度预测块的宽高比值根据所述当前编码单元的尺寸信息得到；
条件4：如果将所述当前编码单元的亮度块划分为至少两个亮度预测块，则划分得到的亮度预测块的的宽和高均大于或者等于第二阈值，所述第二阈值为正整数，所述划分得到的亮度预测块的宽和高根据所述当前编码单元的尺寸信息得到；
条件5：所述当前编码单元的最小边长是第三阈值，且如果将所述当前编码单元的亮度块划分为至少两个亮度预测块，则划分得到的亮度预测块的宽和高均大于或等于第四阈值，所述第三阈值为正整数，所述第四阈值为正整数，所述划分得到的亮度预测块的宽和高根据所述当前编码单元的尺寸信息得到；
根据判断结果，得到所述当前编码单元的预测单元的尺寸信息；
根据所述当前编码单元的预测单元的尺寸信息，得到所述当前编码单元的预测信息。
第三方面，本申请实施例提供了一种视频解码方法，所述方法包括：
对当前编码单元的亮度块按照第一划分方式进行划分，得到亮度预测块；
根据所述第一划分方式，按照如下方式中至少一种得到亮度变换块：
方式1：在所述当前编码单元使用帧内预测方式进行预测的情况下，如果所述第一划分方式为竖直四等分或者非对称竖直二分，对所述亮度块进行竖直四等分方式进行划分得到所述亮度变换块；
方式2：在所述当前编码单元使用帧内预测方式进行预测的情况下，如果所述第一划分方式为水平四分或者非对称水平二分，对所述亮度块进行水平四等分方式进行划分得到所述亮度变换块；
方式3：在所述当前编码单元使用帧间预测方式进行预测的情况下，如果所述第一划分方式为竖直四分或者非对称竖直二分，对所述亮度块进行竖直四等分方式进行划分得到所述亮度变换块或者将所述亮度块作为所述亮度变换块；
方式4：在所述当前编码单元使用帧间预测方式进行预测的情况下，如果所述第一划分方式为水平四分或者非对称水平二分，对所述亮度块进行水平四等分方式进行划分得到所述亮度变换块或者将所述亮度块作为所述亮度变换块；
获取所述亮度变换块的残差信息，以及获取所述亮度预测块的预测信息；
根据所述残差信息和所述预测信息，得到所述亮度块的重建块。
第四方面，本申请实施例提供了一种视频解码方法，所述方法包括：
按照如下方式中至少一种得到当前编码单元的色度变换块：
方式1：在所述当前编码单元使用帧内预测方式进行预测的情况下，将所述当前编码单元的色度块作为所述色度变换块；
方式2：在所述当前编码单元使用帧间预测方式进行预测的情况下，将所述当前编码单元的色度块作为所述色度变换块；
方式3：在所述当前编码单元使用帧间预测方式进行预测的情况下，按照与得到所述当前编码单元的亮度变换块相同的划分方式，得到所述色度变换块；
方式4：在所述当前编码单元使用帧间预测方式进行预测的情况下，如果所述当前编码单元的亮度块按照四等分方式划分为4个亮度变换块且任一亮度变换块的其中一条边的边长为E时，将所述当前编码单元的色度块作为所述色度变换块，E为正整数；
获取所述色度变换块的残差信息，以及获取所述当前编码单元的色度预测块的预测信息；
根据所述残差信息和所述预测信息，得到所述色度块的重建块。
第五方面，提供一种的解码装置，该装置包括用于执行上述第一方面或第二方面或第三方面或第四方面，或者第一方面或第二方面或第三方面或第四方面中的任意一种实现方式中的方法的模块。
第六方面，提供一种解码器，该编解码器包括：相互耦合的非易失性存储器和处理器，所述处理器调用存储在所述存储器中的程序代码以执行第一方面或第二方面或第三方面或第四方面，或者第第一方面或第二方面或第三方面或第四方面中的任意一种实现方式中的方法的部分或全部步骤。
第七方面，提供一种计算机可读存储介质，所述计算机可读存储介质存储了程序代码，其中，所述程序代码包括用于执行第一方面或第二方面或第三方面或第四方面，或者第一方面或第二方面或第三方面或第四方面中的任意一种实现方式中的方法的部分或全部步骤的指令。
第八方面，提供一种计算机程序产品，当所述计算机程序产品在计算机上运行时，使得所述计算机执行第一方面或第二方面或第三方面或第四方面，或者第一方面或第二方面或第三方面或第四方面中的任意一种实现方式中的方法的部分或全部步骤的指令。
本申请还提供一种图像重建方法和装置，能够减小视频编解码的复杂度，提高编解码性能。
第九方面，提供了一种图像重建方法，该方法包括：获取当前编码单元的预测模式，和/或，获取所述当前编码单元的预测划分方式，所述当前编码单元包括亮度编码块和色度编码块，所述预测划分方式为将所述当前编码单元划分成预测块或预测单元的方式；根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块；根据所述变换块，产生所述当前编码单元的重构图像块。
在本申请实施例中，根据所述预测划分方式和/或所述预测模式(不需要解析码流或者只需要解析码流中的少量信息)，就可以得到所述当前编码单元的变换块，此时，根据所述变换块，产生所述当前编码单元的重构图像块，能够减小视频编解码的复杂度，提高编解码效率。
可选地，可以根据所述预测模式，确定所述当前编码单元的预测划分方式。其中，，所述预测模式可以包括帧内预测模式和帧间预测模式。
结合第九方面，在第九方面的某些实现方式中，所述根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块，包括：根据所述预测划分方式和/或所述预测模式，将所述当前编码单元划分成变换块。
在本申请实施例中，根据所述预测划分方式和/或所述预测模式(不需要解析码流或者只需要解析码流中的少量信息)，就可以将所述当前编码单元划分成变换块，因此，能够减小视频编解码的复杂度，提高编解码效率。
结合第九方面，在第九方面的某些实现方式中，所述获取当前编码单元的预测模式，包括：从码流中解析或推导得到所述预测模式，所述预测模式包括帧内预测模式和帧间预测模式。
可以看出上述从码流中解析或推导得到所述预测模式，可以由解码器执行。
可选地，当编码器执行第九方面中的方法时，可以直接获取所述预测模式。
结合第九方面，在第九方面的某些实现方式中，所述获取所述当前编码单元的预测划分方式，包括：根据所述当前编码单元的尺寸，确定所述当前编码单元允许使用的候选预测划分方式；从所述允许使用的候选预测划分方式中确定出所述预测划分方式。
在本申请实施例中，根据所述当前编码单元的尺寸(不需要解析码流或者只需要解析码流中的少量信息)，就可以确定出所述预测划分方式，因此，能够减小视频编解码的复杂度，提高编解码效率。
结合第九方面，在第九方面的某些实现方式中，所述获取所述当前编码单元的预测划分方式，包括：根据所述当前编码单元的尺寸，确定所述当前编码单元所述预测划分方式。
在本申请实施例中，直接根据所述当前编码单元的尺寸(不需要解析码流或者只需要解析码流中的少量信息)，就可以确定出所述预测划分方式，因此，能够减小视频编解码的复杂度，提高编解码效率。
结合第九方面，在第九方面的某些实现方式中，所述方法还包括：在所述预测模式为帧内预测模式的情况下，使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，不对所述色度编码块进行划分，并将所述色度编码块作为色度预测块。
结合第九方面，在第九方面的某些实现方式中，所述方法还包括：在所述预测模式为帧间预测模式的情况下，不对所述当前编码单元进行划分，并将所述当前编码单元作为预测单元。
在本申请实施例中，在所述预测模式为帧间预测模式的情况下，不对所述当前编码单元进行划分，可以避免产生尺寸过小的为编码块，能够提高编解码效率。
结合第九方面，在第九方面的某些实现方式中，所述方法还包括：在所述预测模式为帧间预测模式的情况下，按照以下任一种方式对所述当前编码单元进行划分：使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，使用所述预测划分方式对所述色度编码块进行划分，得到色度预测块；或使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，在所述亮度预测块为两个、且所述两个亮度预测块中至少一个亮度预测块的至少一边的长为4的情况下，不对所述色度编码块进行划分，并将所述色度编码块作为色度预测块。
结合第九方面，在第九方面的某些实现方式中，所述根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块，包括：在所述预测模式为帧内预测模式，且所述亮度编码块的所述预测划分方式为竖直四等分或非对称竖直二分的情况下，使用竖直四等分对所述亮度编码块进行划分，得到亮度变换块，不对所述色度编码块进行划分，并将色度编码块作为色度变换块；或在所述预测模式为帧内预测模式，且所述亮度编码块的所述预测划分方式为水平四等分或非对称水平二分的情况下，使用水平四等分对所述亮度编码块进行划分，得到亮度变换块，不对所述色度编码块进行划分，并将色度编码块作为色度变换块。
在本申请实施例中，直接根据所述预测划分方式和/或所述预测模式(不需要解析码流或者只需要解析码流中的少量信息)，得到所述当前编码单元的变换块，因此，能够减小视频编解码的复杂度，提高编解码效率。
结合第九方面，在第九方面的某些实现方式中，所述根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块，包括：在所述预测模式为帧间预测模式的 情况下，不对所述当前编码单元进行划分，并将所述当前编码单元作为变换单元。
在本申请实施例中，直接根据所述预测划分方式和/或所述预测模式(不需要解析码流或者只需要解析码流中的少量信息)，得到所述当前编码单元的变换块，因此，能够减小视频编解码的复杂度，提高编解码效率。
结合第九方面，在第九方面的某些实现方式中，所述方法还包括：在所述当前编码单元的尺寸满足以下至少一个条件的情况下，确定是否允许对所述当前编码单元进行划分以得到预测块：所述当前编码单元的宽和高的比值小于P，其中，P为正整数；或所述当前编码单元的最大边长等于预设的阈值；在确定允许对所述当前编码单元进行划分以得到预测块的情况下，才执行所述获取所述当前编码单元的预测划分方式。
在本申请实施例中，根据所述当前编码单元的尺寸，就可以确定是否允许对所述当前编码单元进行划分以得到预测块，因此，能够减小视频编解码的复杂度，提高编解码效率。
第十方面，提供了一种图像重建装置，包括：获取单元，用于获取当前编码单元的预测模式，和/或，获取所述当前编码单元的预测划分方式，所述当前编码单元包括亮度编码块和色度编码块，所述预测划分方式为将所述当前编码单元划分成预测块或预测单元的方式；处理单元，用于根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块；重构单元，用于根据所述变换块，产生所述当前编码单元的重构图像块。
在本申请实施例中，根据所述预测划分方式和/或所述预测模式(不需要解析码流或者只需要解析码流中的少量信息)，就可以得到所述当前编码单元的变换块，此时，根据所述变换块，产生所述当前编码单元的重构图像块，能够减小视频编解码的复杂度，提高编解码效率。
可选地，可以根据所述预测模式，确定所述当前编码单元的预测划分方式。其中，，所述预测模式可以包括帧内预测模式和帧间预测模式。
结合第十方面，在第十方面的某些实现方式中，所述处理单元具体用于：根据所述预测划分方式和/或所述预测模式，将所述当前编码单元划分成变换块。
在本申请实施例中，根据所述预测划分方式和/或所述预测模式，可以将所述当前编码单元划分成变换块，因此，能够减小视频编解码的复杂度，提高编解码效率。
结合第十方面，在第十方面的某些实现方式中，所述获取单元具体用于：从码流中解析或推导得到所述预测模式，所述预测模式包括帧内预测模式和帧间预测模式。
可以看出上述从码流中解析或推导得到所述预测模式，可以由解码器执行。
可选地，当编码器执行第九方面中的方法时，可以直接获取所述预测模式。
结合第十方面，在第十方面的某些实现方式中，所述获取单元具体用于：根据所述当前编码单元的尺寸，确定所述当前编码单元允许使用的候选预测划分方式；从所述允许使用的候选预测划分方式中确定出所述预测划分方式。
在本申请实施例中，根据所述当前编码单元的尺寸(不需要解析码流或者只需要解析码流中的少量信息)，就可以确定出所述预测划分方式，因此，能够减小视频编解码的复杂度，提高编解码效率。
结合第十方面，在第十方面的某些实现方式中，所述获取单元具体用于：根据所述当前编码单元的尺寸，确定所述当前编码单元所述预测划分方式。
在本申请实施例中，直接根据所述当前编码单元的尺寸(不需要解析码流或者只需要 解析码流中的少量信息)，就可以确定出所述预测划分方式，因此，能够减小视频编解码的复杂度，提高编解码效率。
结合第十方面，在第十方面的某些实现方式中，所述处理单元还用于：在所述预测模式为帧内预测模式的情况下，使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，不对所述色度编码块进行划分，并将所述色度编码块作为色度预测块。
结合第十方面，在第十方面的某些实现方式中，所述处理单元还用于：在所述预测模式为帧间预测模式的情况下，不对所述当前编码单元进行划分，并将所述当前编码单元作为预测单元。
在本申请实施例中，在所述预测模式为帧间预测模式的情况下，不对所述当前编码单元进行划分，可以避免产生尺寸过小的为编码块，能够提高编解码效率。
结合第十方面，在第十方面的某些实现方式中，所述处理单元还用于：在所述预测模式为帧间预测模式的情况下，按照以下任一种方式对所述当前编码单元进行划分：使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，使用所述预测划分方式对所述色度编码块进行划分，得到色度预测块；或使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，在所述亮度预测块为两个、且所述两个亮度预测块中至少一个亮度预测块的至少一边的长为4的情况下，不对所述色度编码块进行划分，并将所述色度编码块作为色度预测块。
结合第十方面，在第十方面的某些实现方式中，所述处理单元具体用于：在所述预测模式为帧内预测模式，且所述亮度编码块的所述预测划分方式为竖直四等分或非对称竖直二分的情况下，使用竖直四等分对所述亮度编码块进行划分，得到亮度变换块，不对所述色度编码块进行划分，并将色度编码块作为色度变换块；或在所述预测模式为帧内预测模式，且所述亮度编码块的所述预测划分方式为水平四等分或非对称水平二分的情况下，使用水平四等分对所述亮度编码块进行划分，得到亮度变换块，不对所述色度编码块进行划分，并将色度编码块作为色度变换块。
在本申请实施例中，直接根据所述预测划分方式和/或所述预测模式(不需要解析码流或者只需要解析码流中的少量信息)，得到所述当前编码单元的变换块，因此，能够减小视频编解码的复杂度，提高编解码效率。
结合第十方面，在第十方面的某些实现方式中，所述处理单元具体用于：在所述预测模式为帧间预测模式的情况下，不对所述当前编码单元进行划分，并将所述当前编码单元作为变换单元。
在本申请实施例中，直接根据所述预测划分方式和/或所述预测模式(不需要解析码流或者只需要解析码流中的少量信息)，得到所述当前编码单元的变换块，因此，能够减小视频编解码的复杂度，提高编解码效率。
结合第十方面，在第十方面的某些实现方式中，所述处理单元还用于：在所述当前编码单元的尺寸满足以下至少一个条件的情况下，确定是否允许对所述当前编码单元进行划分以得到预测块：所述当前编码单元的宽和高的比值小于P，其中，P为正整数；或所述当前编码单元的最大边长等于预设的阈值；在确定允许对所述当前编码单元进行划分以得到预测块的情况下，才执行所述获取所述当前编码单元的预测划分方式。
在本申请实施例中，根据所述当前编码单元的尺寸，就可以确定是否允许对所述当前 编码单元进行划分以得到预测块，因此，能够减小视频编解码的复杂度，提高编解码效率。
第十一方面，提供了一种解码视频数据的设备，该设备包括：
存储器，用于存储码流形式的视频数据；
视频解码器，用于实施第九方面的任意一种方法的部分或全部步骤。
第十二方面，提供了一种编码视频数据的设备，该设备包括：
存储器，用于存储码流形式的视频数据；
视频编码器，用于实施第九方面的任意一种方法的部分或全部步骤。
第十三方面，本申请实施例提供一种解码视频数据的设备，包括：存储器和处理器，所述处理器调用存储在所述存储器中的程序代码以执行第九方面的任意一种方法的部分或全部步骤。
可选地，上述存储器为非易失性存储器。
可选地，上述存储器与处理器互相耦合在一起。
第十四方面，本申请实施例提供一种计算机可读存储介质，所述计算机可读存储介质存储了程序代码，其中，所述程序代码包括用于执行第九方面的任意一种方法的部分或全部步骤的指令。
第十五方面，本申请实施例提供一种计算机程序产品，当所述计算机程序产品在计算机上运行时，使得所述计算机执行第九方面的任意一种方法的部分或全部步骤。
在本申请实施例中，根据所述预测划分方式和/或所述预测模式(不需要解析码流或者只需要解析码流中的少量信息)，就可以得到所述当前编码单元的变换块，此时，根据所述变换块，产生所述当前编码单元的重构图像块，能够减小视频编解码的复杂度，提高编解码效率。
附图说明
图1中A是用于实现本发明实施例的视频编码及解码系统10实例的框图；
图1中B是用于实现本发明实施例的视频译码系统40实例的框图；
图2是用于实现本发明实施例的编码器20实例结构的框图；
图3是用于实现本发明实施例的解码器30实例结构的框图；
图4是用于实现本发明实施例的视频译码设备400实例的框图；
图5是用于实现本发明实施例的另一种编码装置或解码装置实例的框图；
图6是一种块划分方式的示意性框图；
图7是一种块划分方式的示意性框图；
图8是一种块划分方式的示意性框图；
图9是一种块划分方式的示意性框图；
图10是一种块划分方式的示意性框图；
图11是用于实现本发明实施例的一种视频通信系统示意性框图；
图12是本申请实施例的图像重建方法的示意性流程图；
图13是本申请实施例的四等分划分及非对称划分的示意图；
图14是本申请实施例的图像重建装置的示意性框图；
图15是本申请实施例的图像重建装置的示意性框图。
具体实施方式
下面结合本发明实施例中的附图对本发明实施例进行描述。以下描述中，参考形成本公开一部分并以说明之方式示出本发明实施例的具体方面或可使用本发明实施例的具体方面的附图。应理解，本发明实施例可在其它方面中使用，并可包括附图中未描绘的结构或逻辑变化。因此，以下详细描述不应以限制性的意义来理解，且本发明的范围由所附权利要求书界定。例如，应理解，结合所描述方法的揭示内容可以同样适用于用于执行所述方法的对应设备或系统，且反之亦然。例如，如果描述一个或多个具体方法步骤，则对应的设备可以包含如功能单元等一个或多个单元，来执行所描述的一个或多个方法步骤(例如，一个单元执行一个或多个步骤，或多个单元，其中每个都执行多个步骤中的一个或多个)，即使附图中未明确描述或说明这种一个或多个单元。另一方面，例如，如果基于如功能单元等一个或多个单元描述具体装置，则对应的方法可以包含一个步骤来执行一个或多个单元的功能性(例如，一个步骤执行一个或多个单元的功能性，或多个步骤，其中每个执行多个单元中一个或多个单元的功能性)，即使附图中未明确描述或说明这种一个或多个步骤。进一步，应理解的是，除非另外明确提出，本文中所描述的各示例性实施例和/或方面的特征可以相互组合。
视频编码通常是指处理形成视频或视频序列的图片序列。在视频编码领域，术语“图片(picture)”、“帧(frame)”或“图像(image)”可以用作同义词。本文中使用的视频编码表示视频编码或视频解码。视频编码在源侧执行，通常包括处理(例如，通过压缩)原始视频图片以减少表示该视频图片所需的数据量，从而更高效地存储和/或传输。视频解码在目的地侧执行，通常包括相对于编码器作逆处理，以重构视频图片。实施例涉及的视频图片“编码”应理解为涉及视频序列的“编码”或“解码”。编码部分和解码部分的组合也称为编解码(编码和解码)。
视频序列包括一系列图像(picture)，图像被进一步划分为切片(slice)，切片再被划分为块(block)。视频编码以块为单位进行编码处理，在一些新的视频编码标准中，块的概念被进一步扩展。比如，宏块可进一步划分成多个可用于预测编码的预测块(partition)。或者，采用编码单元(coding unit，CU)，预测单元(prediction unit，PU)和变换单元(transform unit，TU)等基本概念，从功能上划分了多种块单元，并采用全新的基于树结构进行描述。比如CU可以按照四叉树进行划分为更小的CU，而更小的CU还可以继续划分，从而形成一种四叉树结构，CU是对编码图像进行划分和编码的基本单元。对于PU和TU也有类似的树结构，PU可以对应预测块，是预测编码的基本单元。对CU按照划分模式进一步划分成多个PU。TU可以对应变换块，是对预测残差进行变换的基本单元。然而，无论CU，PU还是TU，本质上都属于块(或称图像块)的概念。
通过使用表示为编码树的四叉树结构将CTU拆分为多个CU。在CU层级处作出是否使用图片间(时间)或图片内(空间)预测对图片区域进行编码的决策。每个CU可以根据PU拆分类型进一步拆分为一个、两个或四个PU。一个PU内应用相同的预测过程，并在PU基础上将相关信息传输到解码器。在通过基于PU拆分类型应用预测过程获取残差块之后，可以根据类似于用于CU的编码树的其它四叉树结构将CU分割成变换单元(transform unit，TU)。在视频压缩技术最新的发展中，使用四叉树和二叉树(Quad-tree  and binary tree，QTBT)分割帧来分割编码块。在QTBT块结构中，CU可以为正方形或矩形形状。
本文中，为了便于描述和理解，可将当前编码图像中待编码的图像块称为当前块，例如在编码中，指当前正在编码的块；在解码中，指当前正在解码的块。将参考图像中用于对当前块进行预测的已解码的图像块称为参考块，即参考块是为当前块提供参考信号的块，其中，参考信号表示图像块内的像素值。可将参考图像中为当前块提供预测信号的块为预测块，其中，预测信号表示预测块内的像素值或者采样值或者采样信号。例如，在遍历多个参考块以后，找到了最佳参考块，此最佳参考块将为当前块提供预测，此块称为预测块。
无损视频编码情况下，可以重构原始视频图片，即经重构视频图片具有与原始视频图片相同的质量(假设存储或传输期间没有传输损耗或其它数据丢失)。在有损视频编码情况下，通过例如量化执行进一步压缩，来减少表示视频图片所需的数据量，而解码器侧无法完全重构视频图片，即经重构视频图片的质量相比原始视频图片的质量较低或较差。
H.261的几个视频编码标准属于“有损混合型视频编解码”(即，将样本域中的空间和时间预测与变换域中用于应用量化的2D变换编码结合)。视频序列的每个图片通常分割成不重叠的块集合，通常在块层级上进行编码。换句话说，编码器侧通常在块(视频块)层级处理亦即编码视频，例如，通过空间(图片内)预测和时间(图片间)预测来产生预测块，从当前块(当前处理或待处理的块)减去预测块以获取残差块，在变换域变换残差块并量化残差块，以减少待传输(压缩)的数据量，而解码器侧将相对于编码器的逆处理部分应用于经编码或经压缩块，以重构用于表示的当前块。另外，编码器复制解码器处理循环，使得编码器和解码器生成相同的预测(例如帧内预测和帧间预测)和/或重构，用于处理亦即编码后续块。
下面描述本发明实施例所应用的系统架构。参见图1A，图1A示例性地给出了本发明实施例所应用的视频编码及解码系统10的示意性框图。如图1A所示，视频编码及解码系统10可包括源设备12和目的地设备14，源设备12产生经编码视频数据，因此，源设备12可被称为视频编码装置。目的地设备14可对由源设备12所产生的经编码的视频数据进行解码，因此，目的地设备14可被称为视频解码装置。源设备12、目的地设备14或两个的各种实施方案可包含一或多个处理器以及耦合到所述一或多个处理器的存储器。所述存储器可包含但不限于RAM、ROM、EEPROM、快闪存储器或可用于以可由计算机存取的指令或数据结构的形式存储所要的程序代码的任何其它媒体，如本文所描述。源设备12和目的地设备14可以包括各种装置，包含桌上型计算机、移动计算装置、笔记型(例如，膝上型)计算机、平板计算机、机顶盒、例如所谓的“智能”电话等电话手持机、电视机、相机、显示装置、数字媒体播放器、视频游戏控制台、车载计算机、无线通信设备或其类似者。
虽然图1A将源设备12和目的地设备14绘示为单独的设备，但设备实施例也可以同时包括源设备12和目的地设备14或同时包括两者的功能性，即源设备12或对应的功能性以及目的地设备14或对应的功能性。在此类实施例中，可以使用相同硬件和/或软件，或使用单独的硬件和/或软件，或其任何组合来实施源设备12或对应的功能性以及目的地设备14或对应的功能性。
源设备12和目的地设备14之间可通过链路13进行通信连接，目的地设备14可经由链路13从源设备12接收经编码视频数据。链路13可包括能够将经编码视频数据从源设备12移动到目的地设备14的一或多个媒体或装置。在一个实例中，链路13可包括使得源设备12能够实时将经编码视频数据直接发射到目的地设备14的一或多个通信媒体。在此实例中，源设备12可根据通信标准(例如无线通信协议)来调制经编码视频数据，且可将经调制的视频数据发射到目的地设备14。所述一或多个通信媒体可包含无线和/或有线通信媒体，例如射频(RF)频谱或一或多个物理传输线。所述一或多个通信媒体可形成基于分组的网络的一部分，基于分组的网络例如为局域网、广域网或全球网络(例如，因特网)。所述一或多个通信媒体可包含路由器、交换器、基站或促进从源设备12到目的地设备14的通信的其它设备。
源设备12包括编码器20，另外可选地，源设备12还可以包括图片源16、图片预处理器18、以及通信接口22。具体实现形态中，所述编码器20、图片源16、图片预处理器18、以及通信接口22可能是源设备12中的硬件部件，也可能是源设备12中的软件程序。分别描述如下：
图片源16，可以包括或可以为任何类别的图片捕获设备，用于例如捕获现实世界图片，和/或任何类别的图片或评论(对于屏幕内容编码，屏幕上的一些文字也认为是待编码的图片或图像的一部分)生成设备，例如，用于生成计算机动画图片的计算机图形处理器，或用于获取和/或提供现实世界图片、计算机动画图片(例如，屏幕内容、虚拟现实(virtual reality，VR)图片)的任何类别设备，和/或其任何组合(例如，实景(augmented reality，AR)图片)。图片源16可以为用于捕获图片的相机或者用于存储图片的存储器，图片源16还可以包括存储先前捕获或产生的图片和/或获取或接收图片的任何类别的(内部或外部)接口。当图片源16为相机时，图片源16可例如为本地的或集成在源设备中的集成相机；当图片源16为存储器时，图片源16可为本地的或例如集成在源设备中的集成存储器。当所述图片源16包括接口时，接口可例如为从外部视频源接收图片的外部接口，外部视频源例如为外部图片捕获设备，比如相机、外部存储器或外部图片生成设备，外部图片生成设备例如为外部计算机图形处理器、计算机或服务器。接口可以为根据任何专有或标准化接口协议的任何类别的接口，例如有线或无线接口、光接口。
其中，图片可以视为像素点(picture element)的二维阵列或矩阵。阵列中的像素点也可以称为采样点。阵列或图片在水平和垂直方向(或轴线)上的采样点数目定义图片的尺寸和/或分辨率。为了表示颜色，通常采用三个颜色分量，即图片可以表示为或包含三个采样阵列。例如在RBG格式或颜色空间中，图片包括对应的红色、绿色及蓝色采样阵列。但是，在视频编码中，每个像素通常以亮度/色度格式或颜色空间表示，例如对于YUV格式的图片，包括Y指示的亮度分量(有时也可以用L指示)以及U和V指示的两个色度分量。亮度(luma)分量Y表示亮度或灰度水平强度(例如，在灰度等级图片中两者相同)，而两个色度(chroma)分量U和V表示色度或颜色信息分量。相应地，YUV格式的图片包括亮度采样值(Y)的亮度采样阵列，和色度值(U和V)的两个色度采样阵列。RGB格式的图片可以转换或变换为YUV格式，反之亦然，该过程也称为色彩变换或转换。如果图片是黑白的，该图片可以只包括亮度采样阵列。本发明实施例中，由图片源16传输至图片处理器的图片也可称为原始图片数据17。
图片预处理器18，用于接收原始图片数据17并对原始图片数据17执行预处理，以获取经预处理的图片19或经预处理的图片数据19。例如，图片预处理器18执行的预处理可以包括整修、色彩格式转换(例如，从RGB格式转换为YUV格式)、调色或去噪。
编码器20(或称视频编码器20)，用于接收经预处理的图片数据19，采用相关预测模式(如本文各个实施例中的预测模式)对经预处理的图片数据19进行处理，从而提供经编码图片数据21(下文将进一步基于图2或图4或图5描述编码器20的结构细节)。在一些实施例中，编码器20可以用于执行后文所描述的各个实施例，以实现本发明所描述的色度块预测方法在编码侧的应用。
通信接口22，可用于接收经编码图片数据21，并可通过链路13将经编码图片数据21传输至目的地设备14或任何其它设备(如存储器)，以用于存储或直接重构，所述其它设备可为任何用于解码或存储的设备。通信接口22可例如用于将经编码图片数据21封装成合适的格式，例如数据包，以在链路13上传输。
目的地设备14包括解码器30，另外可选地，目的地设备14还可以包括通信接口28、图片后处理器32和显示设备34。分别描述如下：
通信接口28，可用于从源设备12或任何其它源接收经编码图片数据21，所述任何其它源例如为存储设备，存储设备例如为经编码图片数据存储设备。通信接口28可以用于藉由源设备12和目的地设备14之间的链路13或藉由任何类别的网络传输或接收经编码图片数据21，链路13例如为直接有线或无线连接，任何类别的网络例如为有线或无线网络或其任何组合，或任何类别的私网和公网，或其任何组合。通信接口28可以例如用于解封装通信接口22所传输的数据包以获取经编码图片数据21。
通信接口28和通信接口22都可以配置为单向通信接口或者双向通信接口，以及可以用于例如发送和接收消息来建立连接、确认和交换任何其它与通信链路和/或例如经编码图片数据传输的数据传输有关的信息。
解码器30(或称为解码器30)，用于接收经编码图片数据21并提供经解码图片数据31或经解码图片31(下文将进一步基于图3或图4或图5描述解码器30的结构细节)。在一些实施例中，解码器30可以用于执行后文所描述的各个实施例，以实现本发明所描述的色度块预测方法在解码侧的应用。
图片后处理器32，用于对经解码图片数据31(也称为经重构图片数据)执行后处理，以获得经后处理图片数据33。图片后处理器32执行的后处理可以包括：色彩格式转换(例如，从YUV格式转换为RGB格式)、调色、整修或重采样，或任何其它处理，还可用于将将经后处理图片数据33传输至显示设备34。
显示设备34，用于接收经后处理图片数据33以向例如用户或观看者显示图片。显示设备34可以为或可以包括任何类别的用于呈现经重构图片的显示器，例如，集成的或外部的显示器或监视器。例如，显示器可以包括液晶显示器(liquid crystal display，LCD)、有机发光二极管(organic light emitting diode，OLED)显示器、等离子显示器、投影仪、微LED显示器、硅基液晶(liquid crystal on silicon，LCoS)、数字光处理器(digital light processor，DLP)或任何类别的其它显示器。
虽然，图1A将源设备12和目的地设备14绘示为单独的设备，但设备实施例也可以同时包括源设备12和目的地设备14或同时包括两者的功能性，即源设备12或对应的功 能性以及目的地设备14或对应的功能性。在此类实施例中，可以使用相同硬件和/或软件，或使用单独的硬件和/或软件，或其任何组合来实施源设备12或对应的功能性以及目的地设备14或对应的功能性。
本领域技术人员基于描述明显可知，不同单元的功能性或图1A所示的源设备12和/或目的地设备14的功能性的存在和(准确)划分可能根据实际设备和应用有所不同。源设备12和目的地设备14可以包括各种设备中的任一个，包含任何类别的手持或静止设备，例如，笔记本或膝上型计算机、移动电话、智能手机、平板或平板计算机、摄像机、台式计算机、机顶盒、电视机、相机、车载设备、显示设备、数字媒体播放器、视频游戏控制台、视频流式传输设备(例如内容服务服务器或内容分发服务器)、广播接收器设备、广播发射器设备等，并可以不使用或使用任何类别的操作系统。
编码器20和解码器30都可以实施为各种合适电路中的任一个，例如，一个或多个微处理器、数字信号处理器(digital signal processor，DSP)、专用集成电路(application-specific integrated circuit，ASIC)、现场可编程门阵列(field-programmable gate array，FPGA)、离散逻辑、硬件或其任何组合。如果部分地以软件实施所述技术，则设备可将软件的指令存储于合适的非暂时性计算机可读存储介质中，且可使用一或多个处理器以硬件执行指令从而执行本公开的技术。前述内容(包含硬件、软件、硬件与软件的组合等)中的任一者可视为一或多个处理器。
在一些情况下，图1A中所示视频编码及解码系统10仅为示例，本申请的技术可以适用于不必包含编码和解码设备之间的任何数据通信的视频编码设置(例如，视频编码或视频解码)。在其它实例中，数据可从本地存储器检索、在网络上流式传输等。视频编码设备可以对数据进行编码并且将数据存储到存储器，和/或视频解码设备可以从存储器检索数据并且对数据进行解码。在一些实例中，由并不彼此通信而是仅编码数据到存储器和/或从存储器检索数据且解码数据的设备执行编码和解码。
参见图1B，图1B是根据一示例性实施例的包含图2的编码器20和/或图3的解码器30的视频译码系统40的实例的说明图。视频译码系统40可以实现本发明实施例的各种技术的组合。在所说明的实施方式中，视频译码系统40可以包含成像设备41、编码器20、解码器30(和/或藉由处理单元46的逻辑电路47实施的视频编/解码器)、天线42、一个或多个处理器43、一个或多个存储器44和/或显示设备45。
如图1B所示，成像设备41、天线42、处理单元46、逻辑电路47、编码器20、解码器30、处理器43、存储器44和/或显示设备45能够互相通信。如所论述，虽然用编码器20和解码器30绘示视频译码系统40，但在不同实例中，视频译码系统40可以只包含编码器20或只包含解码器30。
在一些实例中，天线42可以用于传输或接收视频数据的经编码比特流。另外，在一些实例中，显示设备45可以用于呈现视频数据。在一些实例中，逻辑电路47可以通过处理单元46实施。处理单元46可以包含专用集成电路(application-specific integrated circuit，ASIC)逻辑、图形处理器、通用处理器等。视频译码系统40也可以包含可选的处理器43，该可选处理器43类似地可以包含专用集成电路(application-specific integrated circuit，ASIC)逻辑、图形处理器、通用处理器等。在一些实例中，逻辑电路47可以通过硬件实施，如视频编码专用硬件等，处理器43可以通过通用软件、操作系统等实施。另外，存 储器44可以是任何类型的存储器，例如易失性存储器(例如，静态随机存取存储器(Static Random Access Memory，SRAM)、动态随机存储器(Dynamic Random Access Memory，DRAM)等)或非易失性存储器(例如，闪存等)等。在非限制性实例中，存储器44可以由超速缓存内存实施。在一些实例中，逻辑电路47可以访问存储器44(例如用于实施图像缓冲器)。在其它实例中，逻辑电路47和/或处理单元46可以包含存储器(例如，缓存等)用于实施图像缓冲器等。
在一些实例中，通过逻辑电路实施的编码器20可以包含(例如，通过处理单元46或存储器44实施的)图像缓冲器和(例如，通过处理单元46实施的)图形处理单元。图形处理单元可以通信耦合至图像缓冲器。图形处理单元可以包含通过逻辑电路47实施的编码器20，以实施参照图2和/或本文中所描述的任何其它编码器系统或子系统所论述的各种模块。逻辑电路可以用于执行本文所论述的各种操作。
在一些实例中，解码器30可以以类似方式通过逻辑电路47实施，以实施参照图3的解码器30和/或本文中所描述的任何其它解码器系统或子系统所论述的各种模块。在一些实例中，逻辑电路实施的解码器30可以包含(通过处理单元2820或存储器44实施的)图像缓冲器和(例如，通过处理单元46实施的)图形处理单元。图形处理单元可以通信耦合至图像缓冲器。图形处理单元可以包含通过逻辑电路47实施的解码器30，以实施参照图3和/或本文中所描述的任何其它解码器系统或子系统所论述的各种模块。
在一些实例中，天线42可以用于接收视频数据的经编码比特流。如所论述，经编码比特流可以包含本文所论述的与编码视频帧相关的数据、指示符、索引值、模式选择数据等，例如与编码分割相关的数据(例如，变换系数或经量化变换系数，(如所论述的)可选指示符，和/或定义编码分割的数据)。视频译码系统40还可包含耦合至天线42并用于解码经编码比特流的解码器30。显示设备45用于呈现视频帧。
应理解，本发明实施例中对于参考编码器20所描述的实例，解码器30可以用于执行相反过程。关于信令语法元素，解码器30可以用于接收并解析这种语法元素，相应地解码相关视频数据。在一些例子中，编码器20可以将语法元素熵编码成经编码视频比特流。在此类实例中，解码器30可以解析这种语法元素，并相应地解码相关视频数据。
需要说明的是，本发明实施例描述的解码方法主要用于解码过程，此过程在编码器20和解码器30均存在。
参见图2，图2示出用于实现本发明实施例的编码器20的实例的示意性/概念性框图。在图2的实例中，编码器20包括残差计算单元204、变换处理单元206、量化单元208、逆量化单元210、逆变换处理单元212、重构单元214、缓冲器216、环路滤波器单元220、经解码图片缓冲器(decoded picture buffer，DPB)230、预测处理单元260和熵编码单元270。预测处理单元260可以包含帧间预测单元244、帧内预测单元254和模式选择单元262。帧间预测单元244可以包含运动估计单元和运动补偿单元(未图示)。图2所示的编码器20也可以称为混合型视频编码器或根据混合型视频编解码器的视频编码器。
例如，残差计算单元204、变换处理单元206、量化单元208、预测处理单元260和熵编码单元270形成编码器20的前向信号路径，而例如逆量化单元210、逆变换处理单元212、重构单元214、缓冲器216、环路滤波器220、经解码图片缓冲器(decoded picture buffer，DPB)230、预测处理单元260形成编码器的后向信号路径，其中编码器的后向信 号路径对应于解码器的信号路径(参见图3中的解码器30)。
编码器20通过例如输入202，接收图片201或图片201的图像块203，例如，形成视频或视频序列的图片序列中的图片。图像块203也可以称为当前图片块或待编码图片块，图片201可以称为当前图片或待编码图片(尤其是在视频编码中将当前图片与其它图片区分开时，其它图片例如同一视频序列亦即也包括当前图片的视频序列中的先前经编码和/或经解码图片)。
编码器20的实施例可以包括分割单元(图2中未绘示)，用于将图片201分割成多个例如图像块203的块，通常分割成多个不重叠的块。分割单元可以用于对视频序列中所有图片使用相同的块大小以及定义块大小的对应栅格，或用于在图片或子集或图片群组之间更改块大小，并将每个图片分割成对应的块。
在一个实例中，编码器20的预测处理单元260可以用于执行上述分割技术的任何组合。
如图片201，图像块203也是或可以视为具有采样值的采样点的二维阵列或矩阵，虽然其尺寸比图片201小。换句话说，图像块203可以包括，例如，一个采样阵列(例如黑白图片201情况下的亮度阵列)或三个采样阵列(例如，彩色图片情况下的一个亮度阵列和两个色度阵列)或依据所应用的色彩格式的任何其它数目和/或类别的阵列。图像块203的水平和垂直方向(或轴线)上采样点的数目定义图像块203的尺寸。
如图2所示的编码器20用于逐块编码图片201，例如，对每个图像块203执行编码和预测。
残差计算单元204用于基于图片图像块203和预测块265(下文提供预测块265的其它细节)计算残差块205，例如，通过逐样本(逐像素)将图片图像块203的样本值减去预测块265的样本值，以在样本域中获取残差块205。
变换处理单元206用于在残差块205的样本值上应用例如离散余弦变换(discrete cosine transform，DCT)或离散正弦变换(discrete sine transform，DST)的变换，以在变换域中获取变换系数207。变换系数207也可以称为变换残差系数，并在变换域中表示残差块205。
变换处理单元206可以用于应用DCT/DST的整数近似值，例如为AVS，AVS2，AVS3指定的变换。与正交DCT变换相比，这种整数近似值通常由某一因子按比例缩放。为了维持经正变换和逆变换处理的残差块的范数，应用额外比例缩放因子作为变换过程的一部分。比例缩放因子通常是基于某些约束条件选择的，例如，比例缩放因子是用于移位运算的2的幂、变换系数的位深度、准确性和实施成本之间的权衡等。例如，在解码器30侧通过例如逆变换处理单元212为逆变换(以及在编码器20侧通过例如逆变换处理单元212为对应逆变换)指定具体比例缩放因子，以及相应地，可以在编码器20侧通过变换处理单元206为正变换指定对应比例缩放因子。
量化单元208用于例如通过应用标量量化或向量量化来量化变换系数207，以获取经量化变换系数209。经量化变换系数209也可以称为经量化残差系数209。量化过程可以减少与部分或全部变换系数207有关的位深度。例如，可在量化期间将n位变换系数向下舍入到m位变换系数，其中n大于m。可通过调整量化参数(quantization parameter，QP)修改量化程度。例如，对于标量量化，可以应用不同的标度来实现较细或较粗的量化。较 小量化步长对应较细量化，而较大量化步长对应较粗量化。可以通过量化参数(quantization parameter，QP)指示合适的量化步长。例如，量化参数可以为合适的量化步长的预定义集合的索引。例如，较小的量化参数可以对应精细量化(较小量化步长)，较大量化参数可以对应粗糙量化(较大量化步长)，反之亦然。量化可以包含除以量化步长以及例如通过逆量化210执行的对应的量化或逆量化，或者可以包含乘以量化步长。根据例如AVS，AVS2，AVS3的一些标准的实施例可以使用量化参数来确定量化步长。一般而言，可以基于量化参数使用包含除法的等式的定点近似来计算量化步长。可以引入额外比例缩放因子来进行量化和反量化，以恢复可能由于在用于量化步长和量化参数的等式的定点近似中使用的标度而修改的残差块的范数。在一个实例实施方式中，可以合并逆变换和反量化的标度。或者，可以使用自定义量化表并在例如比特流中将其从编码器通过信号发送到解码器。量化是有损操作，其中量化步长越大，损耗越大。
逆量化单元210用于在经量化系数上应用量化单元208的逆量化，以获取经反量化系数211，例如，基于或使用与量化单元208相同的量化步长，应用量化单元208应用的量化方案的逆量化方案。经反量化系数211也可以称为经反量化残差系数211，对应于变换系数207，虽然由于量化造成的损耗通常与变换系数不相同。
逆变换处理单元212用于应用变换处理单元206应用的变换的逆变换，例如，逆离散余弦变换(discrete cosine transform，DCT)或逆离散正弦变换(discrete sine transform，DST)，以在样本域中获取逆变换块213。逆变换块213也可以称为逆变换经反量化块213或逆变换残差块213。
重构单元214(例如，求和器214)用于将逆变换块213(即经重构残差块213)添加至预测块265，以在样本域中获取经重构块215，例如，将经重构残差块213的样本值与预测块265的样本值相加。
可选地，例如线缓冲器216的缓冲器单元216(或简称“缓冲器”216)用于缓冲或存储经重构块215和对应的样本值，用于例如帧内预测。在其它的实施例中，编码器可以用于使用存储在缓冲器单元216中的未经滤波的经重构块和/或对应的样本值来进行任何类别的估计和/或预测，例如帧内预测。
例如，编码器20的实施例可以经配置以使得缓冲器单元216不只用于存储用于帧内预测254的经重构块215，也用于环路滤波器单元220(在图2中未示出)，和/或，例如使得缓冲器单元216和经解码图片缓冲器单元230形成一个缓冲器。其它实施例可以用于将经滤波块221和/或来自经解码图片缓冲器230的块或样本(图2中均未示出)用作帧内预测254的输入或基础。
环路滤波器单元220(或简称“环路滤波器”220)用于对经重构块215进行滤波以获取经滤波块221，从而顺利进行像素转变或提高视频质量。环路滤波器单元220旨在表示一个或多个环路滤波器，例如去块滤波器、样本自适应偏移(sample-adaptive offset，SAO)滤波器或其它滤波器，例如双边滤波器、自适应环路滤波器(adaptive loop filter，ALF)，或锐化或平滑滤波器，或协同滤波器。尽管环路滤波器单元220在图2中示出为环内滤波器，但在其它配置中，环路滤波器单元220可实施为环后滤波器。经滤波块221也可以称为经滤波的经重构块221。经解码图片缓冲器230可以在环路滤波器单元220对经重构编码块执行滤波操作之后存储经重构编码块。
编码器20(对应地，环路滤波器单元220)的实施例可以用于输出环路滤波器参数(例如，样本自适应偏移信息)，例如，直接输出或由熵编码单元270或任何其它熵编码单元熵编码后输出，例如使得解码器30可以接收并应用相同的环路滤波器参数用于解码。
经解码图片缓冲器(decoded picture buffer，DPB)230可以为存储参考图片数据供编码器20编码视频数据之用的参考图片存储器。DPB 230可由多种存储器设备中的任一个形成，例如动态随机存储器(dynamic random access memory，DRAM)(包含同步DRAM(synchronous DRAM，SDRAM)、磁阻式RAM(magnetoresistive RAM，MRAM)、电阻式RAM(resistive RAM，RRAM))或其它类型的存储器设备。可以由同一存储器设备或单独的存储器设备提供DPB 230和缓冲器216。在某一实例中，经解码图片缓冲器(decoded picture buffer，DPB)230用于存储经滤波块221。经解码图片缓冲器230可以进一步用于存储同一当前图片或例如先前经重构图片的不同图片的其它先前的经滤波块，例如先前经重构和经滤波块221，以及可以提供完整的先前经重构亦即经解码图片(和对应参考块和样本)和/或部分经重构当前图片(和对应参考块和样本)，例如用于帧间预测。在某一实例中，如果经重构块215无需环内滤波而得以重构，则经解码图片缓冲器(decoded picture buffer，DPB)230用于存储经重构块215。
预测处理单元260，也称为块预测处理单元260，用于接收或获取图像块203(当前图片201的当前图像块203)和经重构图片数据，例如来自缓冲器216的同一(当前)图片的参考样本和/或来自经解码图片缓冲器230的一个或多个先前经解码图片的参考图片数据231，以及用于处理这类数据进行预测，即提供可以为经帧间预测块245或经帧内预测块255的预测块265。
模式选择单元262可以用于选择预测模式(例如帧内或帧间预测模式)和/或对应的用作预测块265的预测块245或255，以计算残差块205和重构经重构块215。
模式选择单元262的实施例可以用于选择预测模式(例如，从预测处理单元260所支持的那些预测模式中选择)，所述预测模式提供最佳匹配或者说最小残差(最小残差意味着传输或存储中更好的压缩)，或提供最小信令开销(最小信令开销意味着传输或存储中更好的压缩)，或同时考虑或平衡以上两者。模式选择单元262可以用于基于码率失真优化(rate distortion optimization，RDO)确定预测模式，即选择提供最小码率失真优化的预测模式，或选择相关码率失真至少满足预测模式选择标准的预测模式。
下文将详细解释编码器20的实例(例如，通过预测处理单元260)执行的预测处理和(例如，通过模式选择单元262)执行的模式选择。
如上文所述，编码器20用于从(预先确定的)预测模式集合中确定或选择最好或最优的预测模式。预测模式集合可以包括例如帧内预测模式和/或帧间预测模式。
帧内预测模式集合可以包括35种不同的帧内预测模式，例如，如DC(或均值)模式和平面模式的非方向性模式，或如H.265中定义的方向性模式，或者可以包括67种不同的帧内预测模式，例如，如DC(或均值)模式和平面模式的非方向性模式，或如正在发展中的H.266中定义的方向性模式。
在可能的实现中，帧间预测模式集合取决于可用参考图片(即，例如前述存储在DBP230中的至少部分经解码图片)和其它帧间预测参数，例如取决于是否使用整个参考图片或只使用参考图片的一部分，例如围绕当前块的区域的搜索窗区域，来搜索最佳匹配参考 块，和/或例如取决于是否应用如半像素和/或四分之一像素内插的像素内插，帧间预测模式集合例如可包括先进运动矢量(Advanced Motion Vector Prediction，AMVP)模式和融合(merge)模式。具体实施中，帧间预测模式集合可包括本发明实施例改进的基于控制点的AMVP模式，以及，改进的基于控制点的merge模式。在一个实例中，帧内预测单元254可以用于执行下文描述的帧间预测技术的任意组合。
除了以上预测模式，本发明实施例也可以应用跳过模式和/或直接模式。
预测处理单元260可以进一步用于将图像块203分割成较小的块分区或子块，例如，通过迭代使用四叉树(quad-tree，QT)分割、二进制树(binary-tree，BT)分割或三叉树(triple-tree，TT)或者扩展四叉树(EQT,Extended Quad-Tree)分割，或其任何组合，以及用于例如为块分区或子块中的每一个执行预测，其中模式选择包括选择分割的图像块203的树结构和选择应用于块分区或子块中的每一个的预测模式。
帧间预测单元244可以包含运动估计(motion estimation，ME)单元(图2中未示出)和运动补偿(motion compensation，MC)单元(图2中未示出)。运动估计单元用于接收或获取图片图像块203(当前图片201的当前图片图像块203)和经解码图片231，或至少一个或多个先前经重构块，例如，一个或多个其它/不同先前经解码图片231的经重构块，来进行运动估计。例如，视频序列可以包括当前图片和先前经解码图片31，或换句话说，当前图片和先前经解码图片31可以是形成视频序列的图片序列的一部分，或者形成该图片序列。
例如，编码器20可以用于从多个其它图片中的同一或不同图片的多个参考块中选择参考块，并向运动估计单元(图2中未示出)提供参考图片和/或提供参考块的位置(X、Y坐标)与当前块的位置之间的偏移(空间偏移)作为帧间预测参数。该偏移也称为运动向量(motion vector，MV)。
运动补偿单元用于获取帧间预测参数，并基于或使用帧间预测参数执行帧间预测来获取帧间预测块245。由运动补偿单元(图2中未示出)执行的运动补偿可以包含基于通过运动估计(可能执行对子像素精确度的内插)确定的运动/块向量取出或生成预测块。内插滤波可从已知像素样本产生额外像素样本，从而潜在地增加可用于编码图片块的候选预测块的数目。一旦接收到用于当前图片块的PU的运动向量，运动补偿单元246可以在一个参考图片列表中定位运动向量指向的预测块。运动补偿单元246还可以生成与块和视频条带相关联的语法元素，以供解码器30在解码视频条带的图片块时使用。
具体的，上述帧间预测单元244可向熵编码单元270传输语法元素，所述语法元素包括帧间预测参数(比如遍历多个帧间预测模式后选择用于当前块预测的帧间预测模式的指示信息)。可能应用场景中，如果帧间预测模式只有一种，那么也可以不在语法元素中携带帧间预测参数，此时解码端30可直接使用默认的预测模式进行解码。可以理解的，帧间预测单元244可以用于执行帧间预测技术的任意组合。
帧内预测单元254用于获取，例如接收同一图片的图片块203(当前图片块)和一个或多个先前经重构块，例如经重构相相邻块，以进行帧内估计。例如，编码器20可以用于从多个(预定)帧内预测模式中选择帧内预测模式。
编码器20的实施例可以用于基于优化标准选择帧内预测模式，例如基于最小残差(例如，提供最类似于当前图片块203的预测块255的帧内预测模式)或最小码率失真。
帧内预测单元254进一步用于基于如所选择的帧内预测模式的帧内预测参数确定帧内预测块255。在任何情况下，在选择用于块的帧内预测模式之后，帧内预测单元254还用于向熵编码单元270提供帧内预测参数，即提供指示所选择的用于块的帧内预测模式的信息。在一个实例中，帧内预测单元254可以用于执行帧内预测技术的任意组合。
具体的，上述帧内预测单元254可向熵编码单元270传输语法元素，所述语法元素包括帧内预测参数(比如遍历多个帧内预测模式后选择用于当前块预测的帧内预测模式的指示信息)。可能应用场景中，如果帧内预测模式只有一种，那么也可以不在语法元素中携带帧内预测参数，此时解码端30可直接使用默认的预测模式进行解码。
熵编码单元270用于将熵编码算法或方案(例如，可变长度编码(variable length coding，VLC)方案、上下文自适应VLC(context adaptive VLC，CAVLC)方案、算术编码方案、上下文自适应二进制算术编码(context adaptive binary arithmetic coding，CABAC)、基于语法的上下文自适应二进制算术编码(syntax-based context-adaptive binary arithmetic coding，SBAC)、概率区间分割熵(probability interval partitioning entropy，PIPE)编码或其它熵编码方法或技术)应用于经量化残差系数209、帧间预测参数、帧内预测参数和/或环路滤波器参数中的单个或所有上(或不应用)，以获取可以通过输出272以例如经编码比特流21的形式输出的经编码图片数据21。可以将经编码比特流传输到视频解码器30，或将其存档稍后由视频解码器30传输或检索。熵编码单元270还可用于熵编码正被编码的当前视频条带的其它语法元素。
视频编码器20的其它结构变型可用于编码视频流。例如，基于非变换的编码器20可以在没有针对某些块或帧的变换处理单元206的情况下直接量化残差信号。在另一实施方式中，编码器20可具有组合成单个单元的量化单元208和逆量化单元210。
具体的，在本发明实施例中，编码器20可用于实现后文实施例中描述的编码方法。
应当理解的是，视频编码器20的其它的结构变化可用于编码视频流。例如，对于某些图像块或者图像帧，视频编码器20可以直接地量化残差信号而不需要经变换处理单元206处理，相应地也不需要经逆变换处理单元212处理；或者，对于某些图像块或者图像帧，视频编码器20没有产生残差数据，相应地不需要经变换处理单元206、量化单元208、逆量化单元210和逆变换处理单元212处理；或者，视频编码器20可以将经重构图像块作为参考块直接地进行存储而不需要经滤波器220处理；或者，视频编码器20中量化单元208和逆量化单元210可以合并在一起。环路滤波器220是可选的，以及针对无损压缩编码的情况下，变换处理单元206、量化单元208、逆量化单元210和逆变换处理单元212是可选的。应当理解的是，根据不同的应用场景，帧间预测单元244和帧内预测单元254可以是被选择性的启用。
参见图3，图3示出用于实现本发明实施例的解码器30的实例的示意性/概念性框图。视频解码器30用于接收例如由编码器20编码的经编码图片数据(例如，经编码比特流)21，以获取经解码图片231。在解码过程期间，视频解码器30从视频编码器20接收视频数据，例如表示经编码视频条带的图片块的经编码视频比特流及相关联的语法元素。
在图3的实例中，解码器30包括熵解码单元304、逆量化单元310、逆变换处理单元312、重构单元314(例如求和器314)、缓冲器316、环路滤波器320、经解码图片缓冲器330以及预测处理单元360。预测处理单元360可以包含帧间预测单元344、帧内预测 单元354和模式选择单元362。在一些实例中，视频解码器30可执行大体上与参照图2的视频编码器20描述的编码遍次互逆的解码遍次。
熵解码单元304用于对经编码图片数据21执行熵解码，以获取例如经量化系数309和/或经解码的编码参数(图3中未示出)，例如，帧间预测、帧内预测参数、环路滤波器参数和/或其它语法元素中(经解码)的任意一个或全部。熵解码单元304进一步用于将帧间预测参数、帧内预测参数和/或其它语法元素转发至预测处理单元360。视频解码器30可接收视频条带层级和/或视频块层级的语法元素。
逆量化单元310功能上可与逆量化单元110相同，逆变换处理单元312功能上可与逆变换处理单元212相同，重构单元314功能上可与重构单元214相同，缓冲器316功能上可与缓冲器216相同，环路滤波器320功能上可与环路滤波器220相同，经解码图片缓冲器330功能上可与经解码图片缓冲器230相同。
预测处理单元360可以包括帧间预测单元344和帧内预测单元354，其中帧间预测单元344功能上可以类似于帧间预测单元244，帧内预测单元354功能上可以类似于帧内预测单元254。预测处理单元360通常用于执行块预测和/或从经编码数据21获取预测块365，以及从例如熵解码单元304(显式地或隐式地)接收或获取预测相关参数和/或关于所选择的预测模式的信息。
当视频条带经编码为经帧内编码(I)条带时，预测处理单元360的帧内预测单元354用于基于信号表示的帧内预测模式及来自当前帧或图片的先前经解码块的数据来产生用于当前视频条带的图片块的预测块365。当视频帧经编码为经帧间编码(即B或P)条带时，预测处理单元360的帧间预测单元344(例如，运动补偿单元)用于基于运动向量及从熵解码单元304接收的其它语法元素生成用于当前视频条带的视频块的预测块365。对于帧间预测，可从一个参考图片列表内的一个参考图片中产生预测块。视频解码器30可基于存储于DPB 330中的参考图片，使用默认建构技术来建构参考帧列表：列表0和列表1。
预测处理单元360用于通过解析运动向量和其它语法元素，确定用于当前视频条带的视频块的预测信息，并使用预测信息产生用于正经解码的当前视频块的预测块。在本发明的一实例中，预测处理单元360使用接收到的一些语法元素确定用于编码视频条带的视频块的预测模式(例如，帧内或帧间预测)、帧间预测条带类型(例如，B条带、P条带或GPB条带)、用于条带的参考图片列表中的一个或多个的建构信息、用于条带的每个经帧间编码视频块的运动向量、条带的每个经帧间编码视频块的帧间预测状态以及其它信息，以解码当前视频条带的视频块。在本公开的另一实例中，视频解码器30从比特流接收的语法元素包含接收自适应参数集(adaptive parameter set，APS)、序列参数集(sequence parameter set，SPS)、图片参数集(picture parameter set，PPS)或条带标头中的一个或多个中的语法元素。
逆量化单元310可用于逆量化(即，反量化)在比特流中提供且由熵解码单元304解码的经量化变换系数。逆量化过程可包含使用由视频编码器20针对视频条带中的每一视频块所计算的量化参数来确定应该应用的量化程度并同样确定应该应用的逆量化程度。
逆变换处理单元312用于将逆变换(例如，逆DCT、逆整数变换或概念上类似的逆变换过程)应用于变换系数，以便在像素域中产生残差块。
重构单元314(例如，求和器314)用于将逆变换块313(即经重构残差块313)添加到预测块365，以在样本域中获取经重构块315，例如通过将经重构残差块313的样本值与预测块365的样本值相加。
环路滤波器单元320(在编码循环期间或在编码循环之后)用于对经重构块315进行滤波以获取经滤波块321，从而顺利进行像素转变或提高视频质量。在一个实例中，环路滤波器单元320可以用于执行下文描述的滤波技术的任意组合。环路滤波器单元320旨在表示一个或多个环路滤波器，例如去块滤波器、样本自适应偏移(sample-adaptive offset，SAO)滤波器或其它滤波器，例如双边滤波器、自适应环路滤波器(adaptive loop filter，ALF)，或锐化或平滑滤波器，或协同滤波器。尽管环路滤波器单元320在图3中示出为环内滤波器，但在其它配置中，环路滤波器单元320可实施为环后滤波器。
随后将给定帧或图片中的经解码视频块321存储在存储用于后续运动补偿的参考图片的经解码图片缓冲器330中。
解码器30用于例如，藉由输出332输出经解码图片31，以向用户呈现或供用户查看。
视频解码器30的其它变型可用于对压缩的比特流进行解码。例如，解码器30可以在没有环路滤波器单元320的情况下生成输出视频流。例如，基于非变换的解码器30可以在没有针对某些块或帧的逆变换处理单元312的情况下直接逆量化残差信号。在另一实施方式中，视频解码器30可以具有组合成单个单元的逆量化单元310和逆变换处理单元312。
具体的，在本发明实施例中，解码器30用于实现后文实施例中描述的解码方法。
应当理解的是，视频解码器30的其它结构变化可用于解码经编码视频位流。例如，视频解码器30可以不经滤波器320处理而生成输出视频流；或者，对于某些图像块或者图像帧，视频解码器30的熵解码单元304没有解码出经量化的系数，相应地不需要经逆量化单元310和逆变换处理单元312处理。环路滤波器320是可选的；以及针对无损压缩的情况下，逆量化单元310和逆变换处理单元312是可选的。应当理解的是，根据不同的应用场景，帧间预测单元和帧内预测单元可以是被选择性的启用。
应当理解的是，本申请的编码器20和解码器30中，针对某个环节的处理结果可以经过进一步处理后，输出到下一个环节，例如，在插值滤波、运动矢量推导或环路滤波等环节之后，对相应环节的处理结果进一步进行Clip或移位shift等操作。
例如，按照相邻仿射编码块的运动矢量推导得到的当前图像块的控制点的运动矢量，或者推导得到的当前图像块的子块的运动矢量，可以经过进一步处理，本申请对此不做限定。例如，对运动矢量的取值范围进行约束，使其在一定的位宽内。假设允许的运动矢量的位宽为bitDepth，则运动矢量的范围为-2^(bitDepth-1)～2^(bitDepth-1)-1，其中“^”符号表示幂次方。如bitDepth为16，则取值范围为-32768～32767。如bitDepth为18，则取值范围为-131072～131071。又例如，对运动矢量(例如一个8x8图像块内的四个4x4子块的运动矢量MV)的取值进行约束，使得所述四个4x4子块MV的整数部分之间的最大差值不超过N个像素，例如不超过一个像素。
可以通过以下两种方式进行约束，使其在一定的位宽内：
方式1，将运动矢量溢出的高位去除：
ux＝(vx+2 bitDepth)％2 bitDepth
vx＝(ux>＝2 bitDepth-1)？(ux-2 bitDepth):ux
uy＝(vy+2 bitDepth)％2 bitDepth
vy＝(uy>＝2 bitDepth-1)？(uy-2 bitDepth):uy
其中，vx为图像块或所述图像块的子块的运动矢量的水平分量，vy为图像块或所述图像块的子块的运动矢量的垂直分量，ux和uy为中间值；bitDepth表示位宽。
例如vx的值为-32769，通过以上公式得到的为32767。因为在计算机中，数值是以二进制的补码形式存储的，-32769的二进制补码为1,0111,1111,1111,1111(17位)，计算机对于溢出的处理为丢弃高位，则vx的值为0111,1111,1111,1111，则为32767，与通过公式处理得到的结果一致。
方法2，将运动矢量进行Clipping，如以下公式所示：
vx＝Clip3(-2 bitDepth-1,2 bitDepth-1-1,vx)
vy＝Clip3(-2 bitDepth-1,2 bitDepth-1-1,vy)
其中vx为图像块或所述图像块的子块的运动矢量的水平分量，vy为图像块或所述图像块的子块的运动矢量的垂直分量；其中，x、y和z分别对应MV钳位过程Clip3的三个输入值，所述Clip3的定义为，表示将z的值钳位到区间[x,y]之间：
Figure PCTCN2019125393-appb-000001
参见图4，图4是本发明实施例提供的视频译码设备400(例如视频编码设备400或视频解码设备400)的结构示意图。视频译码设备400适于实施本文所描述的实施例。在一个实施例中，视频译码设备400可以是视频解码器(例如图1A的解码器30)或视频编码器(例如图1A的编码器20)。在另一个实施例中，视频译码设备400可以是上述图1A的解码器30或图1A的编码器20中的一个或多个组件。
视频译码设备400包括：用于接收数据的入口端口410和接收单元(Rx)420，用于处理数据的处理器、逻辑单元或中央处理器(CPU)430，用于传输数据的发射器单元(Tx)440和出口端口450，以及，用于存储数据的存储器460。视频译码设备400还可以包括与入口端口410、接收器单元420、发射器单元440和出口端口450耦合的光电转换组件和电光(EO)组件，用于光信号或电信号的出口或入口。
处理器430通过硬件和软件实现。处理器430可以实现为一个或多个CPU芯片、核 (例如，多核处理器)、FPGA、ASIC和DSP。处理器430与入口端口410、接收器单元420、发射器单元440、出口端口450和存储器460通信。处理器430包括译码模块470(例如编码模块470或解码模块470)。编码/解码模块470实现本文中所公开的实施例，以实现本发明实施例所提供的色度块预测方法。例如，编码/解码模块470实现、处理或提供各种编码操作。因此，通过编码/解码模块470为视频译码设备400的功能提供了实质性的改进，并影响了视频译码设备400到不同状态的转换。或者，以存储在存储器460中并由处理器430执行的指令来实现编码/解码模块470。
存储器460包括一个或多个磁盘、磁带机和固态硬盘，可以用作溢出数据存储设备，用于在选择性地执行这些程序时存储程序，并存储在程序执行过程中读取的指令和数据。存储器460可以是易失性和/或非易失性的，可以是只读存储器(ROM)、随机存取存储器(RAM)、随机存取存储器(ternary content-addressable memory，TCAM)和/或静态随机存取存储器(SRAM)。
参见图5，图5是根据一示例性实施例的可用作图1A中的源设备12和目的地设备14中的任一个或两个的装置500的简化框图。装置500可以实现本申请的技术。换言之，图5为本申请实施例的编码设备或解码设备(简称为译码设备500)的一种实现方式的示意性框图。其中，译码设备500可以包括处理器510、存储器530和总线系统550。其中，处理器和存储器通过总线系统相连，该存储器用于存储指令，该处理器用于执行该存储器存储的指令。译码设备的存储器存储程序代码，且处理器可以调用存储器中存储的程序代码执行本申请描述的各种视频编码或解码方法，尤其是各种新的解码的方法。为避免重复，这里不再详细描述。
在本申请实施例中，该处理器510可以是中央处理单元(Central Processing Unit，简称为“CPU”)，该处理器510还可以是其他通用处理器、数字信号处理器(DSP)、专用集成电路(ASIC)、现成可编程门阵列(FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件等。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。
该存储器530可以包括只读存储器(ROM)设备或者随机存取存储器(RAM)设备。任何其他适宜类型的存储设备也可以用作存储器530。存储器530可以包括由处理器510使用总线550访问的代码和数据531。存储器530可以进一步包括操作系统533和应用程序535，该应用程序535包括允许处理器510执行本申请描述的视频编码或解码方法(尤其是本申请描述的解码方法)的至少一个程序。例如，应用程序535可以包括应用1至N，其进一步包括执行在本申请描述的视频编码或解码方法的视频编码或解码应用(简称视频译码应用)。
该总线系统550除包括数据总线之外，还可以包括电源总线、控制总线和状态信号总线等。但是为了清楚说明起见，在图中将各种总线都标为总线系统550。
可选的，译码设备500还可以包括一个或多个输出设备，诸如显示器570。在一个示例中，显示器570可以是触感显示器，其将显示器与可操作地感测触摸输入的触感单元合并。显示器570可以经由总线550连接到处理器510。
下面详细阐述本申请实施例的方案：
关键术语定义
CTU：编码树单元(coding tree unit)，一幅图像由多个CTU构成，一个CTU通常对应于一个方形图像区域，包含这个图像区域中的亮度像素和色度像素(或者也可以只包含亮度像素，或者也可以只包含色度像素)；CTU中还包含语法元素，这些语法元素指示如何将CTU划分成至少一个编码单元(coding unit,CU)，以及解码每个编码单元得到重建图像的方法。
CU：编码单元，通常对应于一个A×B的矩形区域，包含A×B亮度像素和它对应的色度像素，A为矩形的宽，B为矩形的高，A和B可以相同也可以不同，A和B的取值通常为2的整数次幂，例如256、128、64、32、16、8、4。一个编码单元可通过解码处理解码得到一个A×B的矩形区域的重建图像，解码处理通常包括预测、反量化、反变换等处理，产生预测图像和残差，预测图像和残差叠加后得到重建图像。
四叉树:一种树状结构，一个节点可划分为四个子节点。H265视频编码标准采用基于四叉树的CTU划分方式：CTU作为根节点，每个节点对应于一个方形的区域；一个节点可以不再划分(此时它对应的区域为一个CU)，或者将这个节点划分成四个下一层级的节点，即把这个方形区域划分成四个大小相同的方形区域(其长、宽各为划分前区域长、宽的一半)，每个区域对应于一个节点。如图6(a)所示。
二叉树：一种树状结构，一个节点可划分成两个子节点。现有采用二叉树的编码方法中，一个二叉树结构上的节点可以不划分，或者把此节点划分成两个下一层级的节点。划分成两个节点的方式有两种：1)水平二分，将节点对应的区域划分成上、下两个相同大小的区域，每个区域对应于一个节点，如图6(b)所示；或者2)竖直二分，将节点对应的区域划分成左、右两个大小相同的区域，每个区域对应于一个节点，如图6(c)所示。
三叉树：一种树状结构，一个节点可划分成三个子节点。现有采用三叉树的编码方法中，一个三叉树结构上的节点可以不划分，或者把此节点划分成三个下一层级的节点。划分成三个节点的方式有两种：1)水平三分，将节点对应的区域划分成上、中、下三个区域，每个区域对应于一个节点，其中上、中、下三个区域的高分别为节点高的1/4、1/2、1/4，如图6(d)所示；或者2)竖直三分，将节点对应的区域划分成左、中、右三个区域，每个区域对应于一个节点，其中左、中、右三个区域的宽分别为节点高的1/4、1/2、1/4，如图6(e)所示。
视频解码(video decoding)：将视频码流按照特定的语法规则和处理方法恢复成重建图像的处理过程。
视频编码(video encoding)：将图像序列压缩成码流的处理过程；
视频编码(video coding)：video encoding和video decoding的统称，中文译名和video encoding相同。
VTM：JVET组织开发的新式编解码器参考软件。
AVS2:第二代数字音视频编解码技术标准(AVS)
视频编码标准把一帧图像分割成互不重叠的编码树单元(CTU)，CTU的大小可设置为64×64(CTU的大小也可设置为其它值，如JVET参考软件JEM中CTU大小增大为128×128或256×256)。64×64的CTU包含由64列、每列64个像素的矩形像素点阵，每个像素包含亮度分量或/和色度分量。
视频编解码使用基于四叉树(quad-tree，简称QT)的CTU划分方法，将CTU作为 四叉树的根节点(root)，按照四叉树的划分方式，将CTU递归划分成若干个叶节点(leaf node)。一个节点对应于一个图像区域，节点如果不划分，则节点称为叶节点，它对应的图像区域形成一个CU；如果节点继续划分，则节点对应的图像区域划分成四个相同大小的区域(其长和宽各为被划分区域的一半)，每个区域对应一个节点，需要分别确定这些节点是否还会划分。一个节点是否划分由码流中这个节点对应的划分标志位split_cu_flag指示。根节点的四叉树层级(qtDepth)为0，子节点的四叉树层级为父节点的四叉树层级+1。为表述简洁，下文中节点的大小和形状即指节点对应的图像区域的大小和形状。
更具体的，对64×64的CTU节点(四叉树层级为0)，根据它对应的split_cu_flag，可选择不划分，成为1个64×64的CU，或者选择划分为4个32×32的节点(四叉树层级为1)。这四个32×32的节点中的每一个节点，又可以根据它对应的split_cu_flag，选择继续划分或者不划分；如果一个32×32的节点继续划分，则产生四个16×16的节点(四叉树层级为2)。以此类推，直到所有节点都不再划分，这样一个CTU就被划分成一组CU。CU的最小尺寸(size)在SPS中标识，例如8×8为最小CU。在上述递归划分过程中，如果一个节点的尺寸等于最小CU尺寸(minimum CU size)，这个节点默认为不再划分，同时也不需要在码流中包含它的划分标志位。
当解析到一个节点为叶节点后，此叶节点为一个CU，进一步解析CU对应的编码信息(包括CU的预测模式、变换系数等信息，例如H.265中的coding_unit()语法结构体)，然后按照这些编码信息对CU进行预测、反量化、反变换、环路滤波等解码处理，产生这个CU对应的重建图像。四叉树结构使得CTU能够根据图像局部特点划分成合适大小的一组CU，例如平滑区域划分成较大的CU，而纹理丰富区域划分为较小的CU。
一种CTU划分成一组CU的划分方式对应于一个编码树(coding tree)。CTU应当采用何种编码树则通常通过编码器的率失真优化(rate distortion optimization,RDO)技术来确定。编码器尝试多种CTU划分方式，每一种划分方式对应于一个率失真代价(RD cost)；编码器比较各种尝试过的划分方式的RD cost，找到RD cost最小的划分方式，作为该CTU最优的划分方式，用于该CTU的实际编码。编码器尝试的各种CTU划分方式均需要符合解码器规定的划分规则，这些才能够被解码器正确识别。
视频编码标准是基于块的编码方式，首先需要把一帧图像分割成互不重叠的编码树单元(CTU)，CTU的大小可设置为64×64(CTU的大小也可设置为其它值，如JVET参考软件JEM中CTU大小增大为128×128或256×256)。CTU又可以按照四叉树(quad-tree，简称QT)结构划分为若干个编码单元CU，每个CU包含一个亮度编码块(CB)和两个色度编码块(CB)及相应的语法元素(包括CU的预测模式、变换系数等信息，例如H.265中的coding_unit()语法结构体)。编码单元CU还可以进一步划分为一个或者多个预测单元(Prediction Unit，PU)和变换单元(Transform Unit，TU)。
预测单元是进行预测运算的基本单元，包括帧内预测和帧间预测两类。CU决定了本单元包含的所有PU预测方式和划分方式。
变换单元是进行变换和量化的基本单元，它是在CU的基础上划分的。CU到TU的划分使用四叉树划分(quad-tree，QT)，称为“变换树”或者残差四叉树(Residual Quad Tree，RQT)。在JVET中，还可以使用三叉树划分(Triple Tree，TT)，也可以使用二叉树(binary tree，BT)的划分方式。
在视频编解码标准中，一个CU可以划分为多个PU，CU到PU仅一层划分，最小的PU为4x4。如图7所示，一个2Nx2N的CU可以划分为8种PU方式。对于帧间预测时，可选的方式如图7中的8种，对于帧内预测只能是2Nx2N或者NxN的方式。
在上述CU划分PU的划分方案的基础上，AVS2提出了四分(包括水平四分、竖直四分)、非对称划分(asymmetric partition，AMP)的划分方法。所述非对称划分包括非对称水平二分和非对称竖直二分，如下图8所示，所述水平四分、竖直四分如图8(e)和(f)所示。其中当前编码块的尺寸为WxH，即水平方向包含W个像素，竖直方向包含H个像素。
CU划分为多个TU的划分方式为四叉树划分(quad-tree，QT)，还可以是二叉树、三叉树划分、上述的水平四分、竖直四分。
二叉树划分包括水平二分和竖直二分两种方式，CU划分为2个TU。如图9所示。
三叉树划分包括水平三分和竖直三分两种方式，将CU划分为3个TU。水平三分将当前CU水平划分为两个Wx(H/4)大小的TU和一个Wx(H/2)大小的TU；如图10所示。
该技术划分的复杂度较高，并且会产生较小的色度块(特别是2x2、2x4、2x8)，对硬件解码器而言，小块的处理代价较高。然而，现有技术一的划分方式会产生2x2、2x4等小块，不利于硬件解码器的实现。
本发明提出了一种CU划分PB(预测块，prediction block)的方法，根据待划分的CU尺寸，来确定划分PB的划分方式，无需通过码流获取，减小编码和解码的复杂度。
本发明还提出了一种CU划分TB(变换块，transform block)的方法，当CU划分后得到的亮度TB的一个边长为4时，对应的色度TB大小与CU的色度块的大小相同。通过这种方式，可以避免产生边长为2的色度块，降低解码器的最大吞吐率，利于解码器实现。
本发明提出了一种CU划分PB(预测块，prediction block)的方法，根据待划分的CU尺寸，来确定划分PB允许使用的划分方式，减小编码和解码的复杂度。
本发明还提出了一种CU划分TB(变换块，transform block)的方法，可根据PB的划分方式来确定TB的划分方式，通过这种方式，可以减小编解码的复杂度，提高编解码性能。
本发明应用于视频编解码器。视频通信系统如图5所示，18为视频编码器，24为视频解码器。本发明应于18和24模块。
涉及一种视频解码中的编码单元(coding unit,CU)划分为预测块PB和变换块TB进行解码的处理方式。本实施例中的视频数据格式为YUV4:2:0格式。对YUV4:2:2数据可采用类似的方式。
步骤1：解析码流，得到当前编码单元的预测方式。
通过解析码流中相应的语法元素，得到当前编码单元的预测方式是帧间预测还是帧内预测。
步骤2：确定当前编码块(或者称为当前编码单元)是否需要被划分成至少两个亮度PB。
具体的，当前编码块的划分方式可以为四等分(包括水平四等分、垂直四等分)、非对称划分AMP中的至少一种，还可以是其它的划分方式，本发明不做限定。
在一些实现方式中，当前编码块是否需要划分为至少两个亮度PB，可以通过语法元素来进行标识，因此判断当前编码块是否需要划分为至少两个亮度PB，可以从码流中解析得到。
在一些实现方式中，当前编码块是否需要划分为至少两个亮度PB，也可以根据当前编码单元的宽高推导得到，推导方法需要满足以下条件：
条件1：当前编码块的宽高比W/H的值在1/N到N之间(包括1/N或N)，N例如为2。
条件2：当前编码块的最大边长为maxSize(或者称为第一阈值)，例如maxSize为64或者32。
条件3：划分得到的PB的宽高比值在1/M到M之间(包括1/M或M)，M例如为8。
条件4：划分得到的PB的宽和高均大于或者等于阈值minSize(或者称为第二阈值)，其中minSize为大于1的整数，例如minSize为4。
条件5：当前编码块的最小边长是S(或者称为第三阈值)，且划分得到的PB的宽和高均大于或等于K(或者称为第四阈值)，例如S为16，K为4。
如果当前编码块需要被划分成至少两个亮度PB，则执行步骤3至步骤6。
步骤3：确定当前编码块的亮度PB划分方式。
当前编码块的亮度PB划分方式信息通常在码流中传输，可以通过解析码流中相应的语法元素得到当前编码块的亮度PB划分方式。所述当前编码块的亮度PB划分方式解析中，通过当前编码块的宽、高或/和划分得到的亮度PB的宽、高来确定当前编码块允许使用的亮度PB划分方式，确定方法可以包含以下方法中的一个。
方法1：当前编码块的宽和高均小于或等于X时，可使用四等分和AMP划分，其中X为大于16的整数，例如X为32或者64。
方法2：当前编码块的宽和高均等于Y时，只使用四等分，不能使用AMP划分，其中Y为大于16的整数，例如Y为64。
方法3：当前编码块待划分边的边长等于A，且非划分边的边长等于B时，待划分边的划分只能使用四等分，不能使用AMP划分,其中，A、B为大于4的整数，例如A为64、B为32，又如A为32、B为32，待划分边为当前编码块的宽，则待划分边的划分方式指的是竖直四等分、竖直1:3非对称划分、竖直3:1非对称划分；待划分边为当前编码块的高，则待划分边的划分方式指的是水平四等分、水平1:3非对称划分、水平3:1非对称划分。
方法4：当前编码块待划分边的边长等于C，且非划分边的边长等于D时，待划分边的划分不使用四分和AMP。其中，C、D为大于4的整数，例如C为32、D为64，又如C为32、D为32。
方法5：当前编码块待划分边的边长小于阈值T时，待划分边的划分可使用AMP划分，不可使用四等分划分，其中T为大于等于16的整数，如T＝16或T＝32。
上述编码块待划分边为垂直于划分方向的边：当划分方式为竖直四等分、非对称竖直二分时，待划分边为编码块的宽；当划分方式为水平四等分、非对称水平二分时，待划分边为编码块的高。编码块待非划分边为平行于划分方向的边：当划分方式为竖直四等 分、非对称竖直二分时，非划分边为编码块的高；当划分方式为水平四等分、非对称水平二分时，待划分边为编码块的宽。
步骤4：对当前编码块按照对应划分方式进行划分，得到亮度PB和色度PB。
如果当前编码块使用的是帧内预测，其亮度块按照当前编码块的亮度PB划分方式进行划分，得到各个亮度PB；当前编码块的色度块不划分，对应于一个色度PB。
如果当前编码块使用的是帧间预测，可采用以下方式中的一种：
方式一：当前编码块的色度块和亮度块按照当前编码块的亮度PB划分方式进行划分，得到各个亮度PB和色度PB。
方式二：当亮度块划分为至少2个亮度PB时，且划分得到的亮度PB中至少有一条边的边长为4时，色度块不划分，成为一个色度PB；否则，当前编码块的色度块和亮度块按照当前编码块的亮度PB划分方式进行划分，得到各个亮度PB和色度PB。当色度块不划分时，色度分量的运动信息为当前编码块中心位置的亮度PB的运动信息。
所述中心位置是指：若当前编码块的大小为WxH，则其中心位置相对于当前编码块左上顶点的坐标为(W/2,H/2)。
步骤5：确定当前编码块的亮度TB和色度TB划分方式，得到各TB的大小。
当当前编码块使用帧内预测时，可以使用以下方法的一种获取TB。
a)如果亮度PB划分方式为竖直四等分或者非对称竖直二分，其亮度块按照竖直四分方式划分为4个亮度TB。
b)如果亮度PB划分方式为水平四分或者非对称水平二分，其亮度块按照水平四分方式划分为4个亮度TB；
c)色度块不划分，成为一个色度TB。
当当前编码块使用帧间预测时，可以使用以下方法的一种获取TB：
a)如果亮度PB划分方式为竖直四分或者非对称竖直二分，其亮度块可以按照竖直四分方式划分为4个亮度TB或者不划分直接成为1个亮度TB；
b)如果亮度PB划分方式为水平四分或者非对称水平二分，其亮度块可以按照水平四分方式划分为4个TB或者不划分成为1个TB。亮度块是否划分成4个TB还是1个TB可以通过解析码流中的语法元素确定。
c)色度块的TB划分可采用以下方式之一：
方式一：色度块的TB划分方式和亮度块的TB划分方式相同。
方式二：色度块不划分，成为一个色度TB。
方式三：当亮度块按照四分方式划分为4个亮度TB且亮度TB的一条边的边长为E(例如可以为4)时，色度块不划分，成为一个色度TB
步骤6：获取各亮度PB的预测信息，获取各亮度TB的残差信息。
亮度PB的预测信息和亮度TB的残差信息可以解析码流中相应的语法元素得到，也可以通过推导得到。
上述亮度PB的预测信息包括：预测模式(指示帧内预测或帧间预测模式)、帧内预测模式、运动信息等。亮度块的帧内预测模式可以为平面模式(Planar Mode)、直流模式(DC Mode)、角度模式(angular Mode)之一；运动信息可包括预测方向(前向、 后向或双向)、参考帧索引(reference index)、运动矢量(motion vector)等信息。
上述亮度TB的残差信息包括：编码块标志位(coded block flag，cbf)、变换系数、变换类型(例如DCT-2,DST-7,DCT-8)等。
步骤7：获取各色度PB的预测信息，获取色度TB的残差信息。
色度PB的预测信息和色度TB的残差信息可以解析码流中相应的语法元素得到，也可以通过推导得到。
色度PB的帧内预测模式可以为直流模式、平面模式、角度模式、线性模型(linear model)模式之一。
色度TB的变换类型可默认为DCT-2变换。
获得各亮度PB的预测信息和亮度TB的残差信息后，可根据各亮度PB相应的预测模式对各亮度PB执行帧间预测处理或帧内预测处理，得到各亮度PB的帧间预测图像或帧内预测图像。再根据各亮度TB的残差信息，将变换系数经过反量化和反变换处理得到各亮度TB的残差图像。将各亮度PB的预测图像和各亮度TB的残差图像相加，产生亮度块的重建图像。
获得各色度PB的预测信息和色度TB的残差信息后，可根据色度PB的预测模式对色度PB执行帧间预测处理或帧内预测处理，得到色度PB的帧间预测图像或帧内预测图像。再根据色度TB的残差信息，将变换系数经过反量化和反变换处理得到残差图像。将各色度PB的预测图像和各色度TB的残差图像相加，产生色度块的重建图像。
通过多种PB和TB划分，提高编码效率。当前CU可选的PB和TB划分方式根据当前CU的宽和高确定，避免PB大小超过硬件流水单元的大小(如32x32)。另一方面，对使用帧间预测的编码单元，当亮度块划分为4个TB且TB的边长为4时，色度TB限制为不划分，以避免产生边长为2的色度TB。
本发明技术方案带来的有益效果可以减小编码和解码的复杂度。
可以避免产生边长为2的色度块，降低解码器的最大吞吐率，利于硬件解码器实现。
图12是本申请实施例的处理编码块的方法1200的示意性流程图。
应理解，图12所示的处理编码块的方法1200可以由上文中图2所示的编码器20执行，也可以由上文中图3所示的解码器30来执行。图12所示的方法1200包括步骤1210、1220及1230，下面对这些步骤进行详细的介绍。
S1210，获取当前编码单元的预测模式，和/或，获取所述当前编码单元的预测划分方式，所述当前编码单元包括亮度编码块和色度编码块，所述预测划分方式为将所述当前编码单元划分成预测块或预测单元的方式。
其中，所述预测模式可以包括帧内预测模式和帧间预测模式，所述预测划分方式可以包括四等分划分及非对称划分(asymmetric partition，AMP)。
如图13所示，非对称划分可以包括竖直3:1非对称划分、竖直1:3非对称划分、水平1:3非对称划分和水平3:1非对称划分，四等分划分可以包括竖直四等分和水平四等分，其中，当前编码块的尺寸为W*H，即水平方向包含W个像素，竖直方向包含H个像素。
应理解，图13中仅为示例而非限定，本申请中所述当前编码块的预测划分方式也可以包括其他的划分方式，本申请实施例对此并不限定。
可选地，当所述方法1200由编码器执行时，所述获取当前编码单元(coding unit，CU) 的预测模式，可以包括：获取所述预测模式。
当所述方法1200由解码器执行时，所述获取当前编码单元的预测模式，可以包括：从码流中解析或推导得到所述预测模式，所述预测模式包括帧内预测模式和帧间预测模式。
类似地，当所述方法1200由编码器执行时，所述获取所述当前编码单元的预测划分方式，可以包括：获取所述预测划分方式。
当所述方法1200由解码器执行时，所述获取当前编码单元的预测模式，可以包括：根据所述当前编码单元的尺寸，确定所述当前编码单元允许使用的候选预测划分方式；从所述允许使用的候选预测划分方式中确定出所述预测划分方式。
其中，从所述允许使用的候选预测划分方式中确定出所述预测划分方式，可以是指：从码流中解析指示所述预测划分方式的标识，根据所述预测划分方式的标识，从所述允许使用的候选预测划分方式中确定出所述预测划分方式。在本申请实施例中，码流(视频数据)格式可以为YUV4:2:0格式或YUV4:2:2格式，也可以为其他格式，本申请对此并不限定。
或者，所述获取所述当前编码单元的预测划分方式，也可以包括：根据所述当前编码单元的尺寸，确定所述当前编码单元的所述预测划分方式。
在本申请实施例中，根据所述当前编码单元的尺寸(不需要解析码流或者只需要解析码流中的少量信息)，就可以确定出所述预测划分方式，因此，能够减小视频编解码的复杂度，提高编解码效率。
或者，所述获取所述当前编码单元的预测划分方式，还可以包括：根据所述预测模式，确定所述当前编码单元的所述预测划分方式。
在本申请实施例中，根据所述预测模式(不需要解析码流或者只需要解析码流中的少量信息)，就可以确定出所述预测划分方式，因此，能够减小视频编解码的复杂度，提高编解码效率。
具体地，上述根据所述当前编码单元的尺寸，确定所述当前编码单元的所述预测划分方式，可以通过下述方式中的一种来实现：
方式一：
在所述当前编码单元的宽小于或等于M，且所述当前编码单元的高小于或等于M的情况下，所述当前编码单元的预测划分方式为四等分划分或非对称划分，其中，M可以为大于16的整数。例如，M为32或者64。
方式二：
在所述当前编码单元的宽等于N，且所述当前编码单元的高等于N的情况下，所述当前编码单元的预测划分方式为四等分划分，其中，N可以为大于16的整数。例如，N为64。
方式三：
在所述当前编码单元的待划分边的边长为大于4的整数，且所述当前编码单元的非待划分边的边长为大于4的整数的情况下，所述当前编码单元的预测划分方式为四等分划分。
例如，待划分边的边长为64，非待划分边的边长为32；或者，待划分边的边长为32， 非待划分边的边长为32。
其中，所述待划分边为垂直于所述当前编码单元的划分方向的边，所述非待划分边为平行于所述当前编码单元的划分方向的边。
例如，如图13所示，图13中a、b和e的待划分边为编码单元的宽，非待划分边为编码单元的高；图13中c、d和f的待划分边为编码单元的高，非待划分边为编码单元的宽。
方式四：
在所述当前编码单元的待划分边的边长为大于4的整数，且所述当前编码单元的非待划分边的边长为大于4的整数的情况下，所述当前编码单元的预测划分方式不为四等分划分或非对称划分。需要说明的，若所述当前编码单元的预测划分方式包括四等分划分或非对称划分，则此时所述当前编码单元不再划分。
例如，待划分边的边长为32，非待划分边的边长为64；或者，待划分边的边长为32，非待划分边的边长为32。
方式五：
所述当前编码单元的待划分边的边长为小于预设的第一阈值时，所述当前编码单元的预测划分方式为非对称划分，所述预设的第一阈值为大于或等于16的整数，其中，所述第一阈值可以为大于或等于16的整数。例如，所述第一阈值为16；或者，所述第一阈值为32。
其中，所述当前编码单元的待划分边为垂直于划分方向的边。
例如，当预测划分方式为竖直四等分、非对称竖直二分时，待划分边为当前编码单元的宽；当预测划分方式为水平四等分、非对称水平二分时，待划分边为当前编码单元的高。
当前编码单元的待非划分边为平行于划分方向的边。
例如，当预测划分方式为竖直四等分、非对称竖直二分时，非划分边为当前编码单元的高；当预测划分方式为水平四等分、非对称水平二分时，待划分边为当前编码单元的宽。
应理解，上述几种方式仅为示例而非限定，本申请中也可以通过其他的方式确定所述当前编码单元的预测划分方式，本申请实施例对此并不限定。
在本申请实施例中，在S1210之前，所述方法1200还可以包括S1201。
S1201，确定是否允许对所述当前编码单元进行划分以得到预测块。
或者，上述确定是否允许对所述当前编码单元进行划分以得到预测块(prediction block，PB)也可以理解为：确定是否需要对所述当前编码单元进行划分以得到预测块。
可选地，可以根据所述当前编码单元的尺寸，确定是否允许对所述当前编码单元进行划分以得到预测块：
例如，在所述当前编码单元的尺寸满足以下至少一个条件的情况下，可以确定允许对所述当前编码单元进行划分以得到预测块：
1、所述当前编码单元的宽和高的比值小于P，其中；
2、所述当前编码单元的最大边长等于预设的第一阈值；
3、所述当前编码单元进行预划分得到的预测块的宽和高的比值位于1/Q至Q；
4、所述当前编码单元进行预划分得到的预测块的宽和高均大于或者等于预设的第二阈值；
5、所述当前编码块的最小边长等于预设的第三阈值，且所述当前编码单元进行预划分得到的预测块的宽和高均大于或者等于预设的第四阈值。
其中，Q与P为正整数，所述第二阈值可以为大于1的整数。
例如，Q可以为8，所述第一阈值可以为64或32，所述第二阈值可以为4，所述第三阈值可以为16，所述第四阈值可以为4。
需要说明的是，上述预划分是指，预先估计出当前编码单元进行划分后可能得到的预测块，而不是对当前编码单元进行实际上的划分。
可选地，在所述当前编码单元的尺寸不满足上述任一个条件的情况下，可以确定不允许对所述当前编码单元进行划分以得到预测块。
在本申请实施例中，根据所述当前编码单元的尺寸，就可以确定是否允许对所述当前编码单元进行划分以得到预测块，因此，能够减小视频编解码的复杂度，提高编解码效率。
进一步地，可以在确定允许对所述当前编码单元进行划分以得到预测块的情况下，才执行所述获取所述当前编码单元的预测划分方式。
或者，也可以从码流中解析得到语法元素，通过语法元素确定是否允许对所述当前编码单元进行划分以得到预测块。
进一步地，在确定允许对所述当前编码单元进行划分的情况下，可以根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的预测块。
例如，在所述预测模式为帧内预测模式的情况下，可以使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，不对所述色度编码块进行划分，并将所述色度编码块作为色度预测块。
再例如，在所述预测模式为帧间预测模式的情况下，可以不对所述当前编码单元进行划分，并将所述当前编码单元作为预测单元。
在本申请实施例中，在所述预测模式为帧间预测模式的情况下，不对所述当前编码单元进行划分，可以避免产生尺寸过小的为编码块，能够提高编解码效率。
再例如，在所述预测模式为帧间预测模式的情况下，可以按照以下任一种方式对所述当前编码单元进行划分：
方式一：
使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，使用所述预测划分方式对所述色度编码块进行划分，得到色度预测块；
方式二：
使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，在所述亮度预测块为两个、且所述两个亮度预测块中至少一个亮度预测块的至少一边的长为4的情况下，不对所述色度编码块进行划分，并将所述色度编码块作为色度预测块；否则，使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，使用所述预测划分方式对所述色度编码块进行划分，得到色度预测块。
在不对所述色度编码块进行划分的情况下，色度分量的运动信息可以为当前编码单元中心位置的亮度编码块的运动信息。
其中，所述中心位置可以是指：若所述当前编码单元的尺寸为W*H，则所述中心位置相对于所述当前编码单元左上顶点的坐标为(W/2，H/2)。
在本申请实施例中，直接根据所述预测划分方式和/或所述预测模式(不需要解析码流或者只需要解析码流中的少量信息)，得到所述当前编码单元的变换块，因此，能够减小视频编解码的复杂度，提高编解码效率。
S1220，根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块。
可选地，可以根据所述预测划分方式和所述预测模式，得到所述当前编码单元的变换块(transform block，TB)，或者，也可以根据所述预测划分方式，得到所述当前编码单元的变换块，或者，还可以根据所述预测模式，得到所述当前编码单元的变换块。
在本申请实施例中，根据所述预测划分方式和/或所述预测模式(不需要解析码流或者只需要解析码流中的少量信息)，就可以将所述当前编码单元划分成变换块，因此，能够减小视频编解码的复杂度，提高编解码效率。
可选地，所述根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块，可以包括：根据所述预测划分方式和/或所述预测模式，将所述当前编码单元划分成变换块。
例如，在所述预测模式为帧内预测模式，且所述亮度编码块的所述预测划分方式为竖直四等分或非对称竖直二分的情况下，可以使用竖直四等分对所述亮度编码块进行划分，得到亮度变换块，不对所述色度编码块进行划分，并将色度编码块作为色度变换块。
或者，在所述预测模式为帧内预测模式，且所述亮度编码块的所述预测划分方式为水平四等分或非对称水平二分的情况下，可以使用水平四等分对所述亮度编码块进行划分，得到亮度变换块，不对所述色度编码块进行划分，并将色度编码块作为色度变换块。
或者，在所述预测模式为帧内预测模式，也可以不对所述当前编码单元进行划分，并将所述当前编码单元作为变换单元。也就是说，可以不对亮度编码块进行划分，直接得到亮度变换块，同样地，也可以不对色度编码块进行划分，直接得到色度变换块。
再例如，在所述预测模式为帧间预测模式的情况下，可以按照以下任一种方式将所述当前编码单元划分成变换块：
方式一：
在所述预测模式为帧间预测模式，且所述亮度编码块的所述预测划分方式为竖直四等分或非对称竖直二分的情况下，可以使用竖直四等分对所述亮度编码块进行划分，得到亮度变换块。
对于所述色度编码块，可以不对所述色度编码块进行划分，并将色度编码块作为色度变换块，或者，也可以使用竖直四等分对所述色度编码块进行划分，或者，还可以在按照竖直四等分对所述色度编码块进行预划分，得到的色度变换块的其中一条边的边长为4时，不对所述色度编码块进行划分，将色度编码块作为色度变换块。
方式二：
在所述预测模式为帧间预测模式，且所述亮度编码块的所述预测划分方式为水平四等分或非对称水平二分的情况下，可以使用水平四等分对所述亮度编码块进行划分，得到亮度变换块。
对于所述色度编码块，可以不对所述色度编码块进行划分，并将色度编码块作为色度变换块，或者，也可以使用水平四等分对所述色度编码块进行划分，或者，还可以在按照水平四等分对所述色度编码块进行预划分，得到的色度变换块的其中一条边的边长为4 时，不对所述色度编码块进行划分，将色度编码块作为色度变换块。
方式三：
在所述预测模式为帧间预测模式的情况下，可以不对所述当前编码单元进行划分，并将所述当前编码单元作为变换单元。也就是说，可以不对亮度编码块进行划分，直接得到亮度变换块，同样地，也可以不对色度编码块进行划分，直接得到色度变换块。
在本申请实施例中，直接根据所述预测划分方式和/或所述预测模式(不需要解析码流或者只需要解析码流中的少量信息)，得到所述当前编码单元的变换块，因此，能够减小视频编解码的复杂度，提高编解码效率。
S1230，根据所述变换块，产生所述当前编码单元的重构图像块。
可选地，可以根据所述预测块和所述变换块，产生所述当前编码单元的重构图像块。
具体地，可以从码流中解析或推导得到所述亮度预测块的预测信息和所述亮度变换块的残差信息。
其中，所述亮度预测块的预测信息可以包括：预测模式、帧内预测模式及运动信息等。预测模式可以指示帧内预测模式或帧间预测模式，帧内预测模式可以为平面模式(planar mode)、直流模式(DC mode)或角度模式(angular mode)；运动信息可以包括预测方向(前向、后向或双向)、参考帧索引(reference index)或运动矢量(motion vector)等信息。
所述亮度变换块的残差信息可以包括：编码块标志位(coded block flag，cbf)、变换系数、变换类型(例如DCT-2,DST-7,DCT-8)等。
在获得各亮度预测块的预测信息和亮度变换块的残差信息后，可以根据各亮度预测块对应的预测模式对各亮度预测块执行帧间预测处理或帧内预测处理，得到各亮度预测块的帧间预测图像或帧内预测图像。再根据各亮度变换块的残差信息，将变换系数经过反量化和反变换处理得到各亮度变换块的残差图像。将各亮度预测块的预测图像和各亮度变换块的残差图像相加，产生亮度块的重建图像。
类似地，可以从码流中解析或推导得到所述色度预测块的预测信息和所述色度变换块的残差信息。
其中，所述色度预测块的帧内预测模式可以为直流模式、平面模式、角度模式或线性模型(linear model)模式。
可选地，所述色度变换块的变换类型可以为DCT-2变换。
在获得各色度预测块的预测信息和色度变换块的残差信息后，可以根据各色度预测块对应的预测模式对色度预测块执行帧间预测处理或帧内预测处理，得到色度预测块的帧间预测图像或帧内预测图像。再根据色度变换块的残差信息，将变换系数经过反量化和反变换处理得到残差图像。将各色度预测块的预测图像和各色度变换块的残差图像相加，产生色度块的重建图像。
此时，根据所述亮度块的重建图像和所述色度块的重建图像，可以产生所述当前编码单元的重构图像块。
在本申请实施例中，根据所述预测划分方式和/或所述预测模式(不需要解析码流或者只需要解析码流中的少量信息)，就可以得到所述当前编码单元的变换块，此时，根据所述变换块，产生所述当前编码单元的重构图像块，能够减小视频编解码的复杂度，提高 编解码效率。
图14是本申请实施例的图像重建装置的示意性框图。图14所示的图像重建装置5000包括：
获取单元5001，用于获取当前编码单元的预测模式，和/或，获取所述当前编码单元的预测划分方式，所述当前编码单元包括亮度编码块和色度编码块，所述预测划分方式为将所述当前编码单元划分成预测块或预测单元的方式；
处理单元5002，用于根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块；
重构单元5003，用于根据所述变换块，产生所述当前编码单元的重构图像块。
在本申请实施例中，根据所述预测划分方式和/或所述预测模式(不需要解析码流或者只需要解析码流中的少量信息)，就可以得到所述当前编码单元的变换块，此时，根据所述变换块，产生所述当前编码单元的重构图像块，能够减小视频编解码的复杂度，提高编解码效率。
可选地，所述处理单元5002具体用于：根据所述预测划分方式和/或所述预测模式，将所述当前编码单元划分成变换块。
可选地，所述获取单元5001具体用于：从码流中解析或推导得到所述预测模式，所述预测模式包括帧内预测模式和帧间预测模式。
可选地，所述获取单元5001具体用于：根据所述当前编码单元的尺寸，确定所述当前编码单元允许使用的候选预测划分方式；从所述允许使用的候选预测划分方式中确定出所述预测划分方式。
可选地，所述获取单元5001具体用于：根据所述当前编码单元的尺寸，确定所述当前编码单元所述预测划分方式。
可选地，所述处理单元5002还用于：在所述预测模式为帧内预测模式的情况下，使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，不对所述色度编码块进行划分，并将所述色度编码块作为色度预测块。
可选地，所述处理单元5002还用于：在所述预测模式为帧间预测模式的情况下，不对所述当前编码单元进行划分，并将所述当前编码单元作为预测单元。
可选地，所述处理单元5002还用于：在所述预测模式为帧间预测模式的情况下，按照以下任一种方式对所述当前编码单元进行划分：使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，使用所述预测划分方式对所述色度编码块进行划分，得到色度预测块；或使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，在所述亮度预测块为两个、且所述两个亮度预测块中至少一个亮度预测块的至少一边的长为4的情况下，不对所述色度编码块进行划分，并将所述色度编码块作为色度预测块。
可选地，所述处理单元5002具体用于：在所述预测模式为帧内预测模式，且所述亮度编码块的所述预测划分方式为竖直四等分或非对称竖直二分的情况下，使用竖直四等分对所述亮度编码块进行划分，得到亮度变换块，不对所述色度编码块进行划分，并将色度编码块作为色度变换块；或在所述预测模式为帧内预测模式，且所述亮度编码块的所述预测划分方式为水平四等分或非对称水平二分的情况下，使用水平四等分对所述亮度编码块进行划分，得到亮度变换块，不对所述色度编码块进行划分，并将色度编码块作为色度变 换块。
可选地，所述处理单元5002具体用于：在所述预测模式为帧间预测模式的情况下，不对所述当前编码单元进行划分，并将所述当前编码单元作为变换单元。
可选地，所述处理单元5002还用于：在所述当前编码单元的尺寸满足以下至少一个条件的情况下，确定是否允许对所述当前编码单元进行划分以得到预测块：所述当前编码单元的宽和高的比值小于P，其中，P为正整数；或所述当前编码单元的最大边长等于预设的阈值；在确定允许对所述当前编码单元进行划分以得到预测块的情况下，才执行所述获取所述当前编码单元的预测划分方式。
上述图像重建装置5000既可以是编码端设备，也可以是解码端设备。
当上述图像重建装置5000为编码端设备时，图像重建装置5000中的获取单元5001可以对应于图2所示的编码器20中的预测处理单元260、处理单元5002可以对应于图2所示的编码器20中的预测处理单元260，变换处理单元206，或者逆变换处理单元212，或者是图2中未示出的用于执行快划分的单元，重构单元5003可以对应于图2所示的编码器20中的逆量化单元210、逆变换处理单元212、残差计算单元204以及重构单元214中至少一项。
当上述图像重建装置5000为解码端设备时，图像重建装置5000中的获取单元5001可以对应于图3所示的解码器30中的预测处理单元360或者熵解码单元304，处理单元5002可以对应于图3所示的解码器30中的预测处理单元360，逆变换处理单元312或者图3中未示出的用于执行快划分的单元，重构单元5003可以对应于图3所示的解码器30中的逆量化单元310、逆变换处理单元312、以及重构单元314中至少一项。
当上述图像重建装置5000为编码端设备时，图像重建装置5000中的获取单元5001、处理单元5002和重构单元5003可以对应于图4所示的处理器430中的编码/解码模块470，该编码/解码模块470能够执行图像重建装置5000执行的各个步骤。
当上述图像重建装置5000为解码端设备时，图像重建装置5000中的获取单元5001、处理单元5002和重构单元5003可以对应于图4所示的处理器430中的编码/解码模块470，该编码/解码模块470能够执行图像重建装置5000执行的各个步骤。
上述图像重建装置5000可在各种各样的装置或设备中实施，包含无线手持机、集成电路(IC)或一组IC(例如，芯片组)。本申请中描述各种组件、模块或单元是为了强调用于执行所揭示的技术的装置的功能方面，但未必需要由不同硬件单元实现。实际上，如上文所描述，各种单元可结合合适的软件和/或固件组合在编码解码器硬件单元中，或者通过互操作硬件单元(包含如上文所描述的一或多个处理器)来提供，本申请实施例中对此并不限定。
另外，上述图像重建装置5000还可以称为编解码设备或者编解码器，通过图像重建装置5000能够实现对视频图像的编码或者解码。
上述单元具体的执行动作可参考上述方法实施例，在此不再赘述。
图15是本申请实施例的图像重建装置的示意性框图。图15所示的图像重建装置6000包括：
存储器6001，用于存储程序；
处理器6002，用于执行存储器6001存储的程序，当存储器6001中存储的程序被执 行时，所述处理器6002用于：
获取当前编码单元的预测模式，和/或，获取所述当前编码单元的预测划分方式，所述当前编码单元包括亮度编码块和色度编码块，所述预测划分方式为将所述当前编码单元划分成预测块或预测单元的方式；
根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块；
根据所述变换块，产生所述当前编码单元的重构图像块。
上述图像重建装置5000中的获取单元5001、处理单元5002和重构单元5003可以对应于图像重建装置6000中的处理器6002，该处理器6002能够实现图像重建装置5000中的获取单元5001、处理单元5002和重构单元5003的功能。
上述图像重建装置6000中的存储器6001可以对应于图5中的存储器530，处理器6002可以对应于图5中的处理器510，该图像重建装置6000可以实现上述图12中的图像重建方法中的各个实施例，该图像重建装置6000也能够执行图像重建装置5000执行的各个步骤。
另外，与上述图像重建装置5000类似，图像重建装置6000既可以是编码端设备，也可以是解码端设备。
同样的，上述图像重建装置6000还可以称为编解码设备或者编解码器，通过图像重建装置6000能够实现对视频图像的编码或者解码。
处理器6002具体的执行动作可参考上述方法实施例，在此不再赘述。
应理解，本申请实施例中的处理器可以为中央处理单元(central processing unit，CPU)，该处理器还可以是其他通用处理器、数字信号处理器(digital signal processor，DSP)、专用集成电路(application specific integrated circuit，ASIC)、现成可编程门阵列(field programmable gate array，FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件等。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。
还应理解，本申请实施例中的存储器可以是易失性存储器或非易失性存储器，或可包括易失性和非易失性存储器两者。其中，非易失性存储器可以是只读存储器(read-only memory，ROM)、可编程只读存储器(programmable ROM，PROM)、可擦除可编程只读存储器(erasable PROM，EPROM)、电可擦除可编程只读存储器(electrically EPROM，EEPROM)或闪存。易失性存储器可以是随机存取存储器(random access memory，RAM)，其用作外部高速缓存。通过示例性但不是限制性说明，许多形式的随机存取存储器(random access memory，RAM)可用，例如静态随机存取存储器(static RAM，SRAM)、动态随机存取存储器(DRAM)、同步动态随机存取存储器(synchronous DRAM，SDRAM)、双倍数据速率同步动态随机存取存储器(double data rate SDRAM，DDR SDRAM)、增强型同步动态随机存取存储器(enhanced SDRAM，ESDRAM)、同步连接动态随机存取存储器(synchlink DRAM，SLDRAM)和直接内存总线随机存取存储器(direct rambus RAM，DR RAM)。
上述实施例，可以全部或部分地通过软件、硬件、固件或其他任意组合来实现。当使用软件实现时，上述实施例可以全部或部分地以计算机程序产品的形式实现。所述计算机程序产品包括一个或多个计算机指令或计算机程序。在计算机上加载或执行所述计算机指 令或计算机程序时，全部或部分地产生按照本申请实施例所述的流程或功能。所述计算机可以为通用计算机、专用计算机、计算机网络、或者其他可编程装置。所述计算机指令可以存储在计算机可读存储介质中，或者从一个计算机可读存储介质向另一个计算机可读存储介质传输，例如，所述计算机指令可以从一个网站站点、计算机、服务器或数据中心通过有线(例如红外、无线、微波等)方式向另一个网站站点、计算机、服务器或数据中心进行传输。所述计算机可读存储介质可以是计算机能够存取的任何可用介质或者是包含一个或多个可用介质集合的服务器、数据中心等数据存储设备。所述可用介质可以是磁性介质(例如，软盘、硬盘、磁带)、光介质(例如，DVD)、或者半导体介质。半导体介质可以是固态硬盘。
本申请实施例定义接入网到终端的单向通信链路为下行链路，在下行链路上传输的数据为下行数据，下行数据的传输方向称为下行方向；而终端到接入网的单向通信链路为上行链路，在上行链路上传输的数据为上行数据，上行数据的传输方向称为上行方向。
本申请实施例中所述的资源也可以称为传输资源，包括时域资源、频域资源、码道资源中的一种或多种，可以用于在上行通信过程或者下行通信过程中承载数据或信令。
应理解，本文中术语“和/或”，仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，本文中字符“/”，表示前后关联对象是一种“或”的关系。
应理解，在本发明实施例中，“与A相应的B”表示B与A相关联，根据A可以确定B。但还应理解，根据A确定B并不意味着仅仅根据A确定B，还可以根据A和/或其它信息确定B。
本申请实施例中出现的“多个”是指两个或两个以上。
本申请实施例中出现的第一、第二等描述，仅作示意与区分描述对象之用，没有次序之分，也不表示本申请实施例中对设备个数的特别限定，不能构成对本申请实施例的任何限制。
本申请实施例中出现的“连接”是指直接连接或者间接连接等各种连接方式，以实现设备间的通信，本申请实施例对此不做任何限定。
本申请实施例中出现的“传输”(transmit/transmission)如无特别说明，是指双向传输，包含发送和/或接收的动作。具体地，本申请实施例中的“传输”包含数据的发送，数据的接收，或者数据的发送和数据的接收。或者说，这里的数据传输包括上行和/或下行数据传输。数据可以包括信道和/或信号，上行数据传输即上行信道和/或上行信号传输，下行数据传输即下行信道和/或下行信号传输。
本申请实施例中出现的业务(service)是指终端从网络侧获取的通信服务，包括控制面业务和/或数据面业务，例如语音业务、数据流量业务等。业务的发送或接收包括业务相关的数据(data)或信令(signaling)的发送或接收。
本申请实施例中出现的“网络”与“系统”表达的是同一概念，通信系统即为通信网络。
应理解，在本申请的各种实施例中，上述各过程的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本申请实施例的实施过程构成任何限定。
本领域技术人员能够领会，结合本文公开描述的各种说明性逻辑框、模块和算法步骤 所描述的功能可以硬件、软件、固件或其任何组合来实施。如果以软件来实施，那么各种说明性逻辑框、模块、和步骤描述的功能可作为一或多个指令或代码在计算机可读媒体上存储或传输，且由基于硬件的处理单元执行。计算机可读媒体可包含计算机可读存储媒体，其对应于有形媒体，例如数据存储媒体，或包括任何促进将计算机程序从一处传送到另一处的媒体(例如，根据通信协议)的通信媒体。以此方式，计算机可读媒体大体上可对应于(1)非暂时性的有形计算机可读存储媒体，或(2)通信媒体，例如信号或载波。数据存储媒体可为可由一或多个计算机或一或多个处理器存取以检索用于实施本申请中描述的技术的指令、代码和/或数据结构的任何可用媒体。计算机程序产品可包含计算机可读媒体。
作为实例而非限制，此类计算机可读存储媒体可包括RAM、ROM、EEPROM、CD-ROM或其它光盘存储装置、磁盘存储装置或其它磁性存储装置、快闪存储器或可用来存储指令或数据结构的形式的所要程序代码并且可由计算机存取的任何其它媒体。并且，任何连接被恰当地称作计算机可读媒体。举例来说，如果使用同轴缆线、光纤缆线、双绞线、数字订户线(DSL)或例如红外线、无线电和微波等无线技术从网站、服务器或其它远程源传输指令，那么同轴缆线、光纤缆线、双绞线、DSL或例如红外线、无线电和微波等无线技术包含在媒体的定义中。但是，应理解，所述计算机可读存储媒体和数据存储媒体并不包括连接、载波、信号或其它暂时媒体，而是实际上针对于非暂时性有形存储媒体。如本文中所使用，磁盘和光盘包含压缩光盘(CD)、激光光盘、光学光盘、数字多功能光盘(DVD)和蓝光光盘，其中磁盘通常以磁性方式再现数据，而光盘利用激光以光学方式再现数据。以上各项的组合也应包含在计算机可读媒体的范围内。
可通过例如一或多个数字信号处理器(DSP)、通用微处理器、专用集成电路(ASIC)、现场可编程逻辑阵列(FPGA)或其它等效集成或离散逻辑电路等一或多个处理器来执行指令。因此，如本文中所使用的术语“处理器”可指前述结构或适合于实施本文中所描述的技术的任一其它结构中的任一者。另外，在一些方面中，本文中所描述的各种说明性逻辑框、模块、和步骤所描述的功能可以提供于经配置以用于编码和解码的专用硬件和/或软件模块内，或者并入在组合编解码器中。而且，所述技术可完全实施于一或多个电路或逻辑元件中。
本申请的技术可在各种各样的装置或设备中实施，包含无线手持机、集成电路(IC)或一组IC(例如，芯片组)。本申请中描述各种组件、模块或单元是为了强调用于执行所揭示的技术的装置的功能方面，但未必需要由不同硬件单元实现。实际上，如上文所描述，各种单元可结合合适的软件和/或固件组合在编码解码器硬件单元中，或者通过互操作硬件单元(包含如上文所描述的一或多个处理器)来提供。
在上述实施例中，对各个实施例的描述各有侧重，某个实施例中没有详述的部分，可以参见其他实施例的相关描述。
以上所述，仅为本申请示例性的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到的变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应该以权利要求的保护范围为准。

Claims (23)

  1. 一种图像重建方法，其特征在于，包括：
    获取当前编码单元的预测模式，和/或，获取所述当前编码单元的预测划分方式，所述当前编码单元包括亮度编码块和色度编码块，所述预测划分方式为将所述当前编码单元划分成预测块或预测单元的方式；
    根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块；
    根据所述变换块，产生所述当前编码单元的重构图像块。
  2. 根据权利要求1所述的方法，其特征在于，所述根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块，包括：
    根据所述预测划分方式和/或所述预测模式，将所述当前编码单元划分成变换块。
  3. 根据权利要求1或2所述的方法，其特征在于，所述获取当前编码单元的预测模式，包括：
    从码流中解析或推导得到所述预测模式，所述预测模式包括帧内预测模式和帧间预测模式。
  4. 根据权利要求1至3中任一项所述的方法，其特征在于，所述获取所述当前编码单元的预测划分方式，包括：
    根据所述当前编码单元的尺寸，确定所述当前编码单元允许使用的候选预测划分方式；
    从所述允许使用的候选预测划分方式中确定出所述预测划分方式。
  5. 根据权利要求1至4中任一项所述的方法，其特征在于，所述获取所述当前编码单元的预测划分方式，包括：
    根据所述当前编码单元的尺寸，确定所述当前编码单元所述预测划分方式。
  6. 根据权利要求1至5中任一项所述的方法，其特征在于，所述方法还包括：
    在所述预测模式为帧内预测模式的情况下，使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，不对所述色度编码块进行划分，并将所述色度编码块作为色度预测块。
  7. 根据权利要求1至5中任一项所述的方法，其特征在于，所述方法还包括：
    在所述预测模式为帧间预测模式的情况下，不对所述当前编码单元进行划分，并将所述当前编码单元作为预测单元。
  8. 根据权利要求1至7中任一项所述的方法，其特征在于，所述方法还包括：
    在所述预测模式为帧间预测模式的情况下，按照以下任一种方式对所述当前编码单元进行划分：
    使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，使用所述预测划分方式对所述色度编码块进行划分，得到色度预测块；或
    使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，在所述亮度预测块为两个、且所述两个亮度预测块中至少一个亮度预测块的至少一边的长为4的情况下，不对所述色度编码块进行划分，并将所述色度编码块作为色度预测块。
  9. 根据权利要求1至8中任一项所述的方法，其特征在于，所述根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块，包括：
    在所述预测模式为帧内预测模式，且所述亮度编码块的所述预测划分方式为竖直四等分或非对称竖直二分的情况下，使用竖直四等分对所述亮度编码块进行划分，得到亮度变换块，不对所述色度编码块进行划分，并将色度编码块作为色度变换块；或
    在所述预测模式为帧内预测模式，且所述亮度编码块的所述预测划分方式为水平四等分或非对称水平二分的情况下，使用水平四等分对所述亮度编码块进行划分，得到亮度变换块，不对所述色度编码块进行划分，并将色度编码块作为色度变换块。
  10. 根据权利要求1至8中任一项所述的方法，其特征在于，所述根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块，包括：
    在所述预测模式为帧间预测模式的情况下，不对所述当前编码单元进行划分，并将所述当前编码单元作为变换单元。
  11. 根据权利要求1至10中任一项所述的方法，其特征在于，所述方法还包括：
    在所述当前编码单元的尺寸满足以下至少一个条件的情况下，确定是否允许对所述当前编码单元进行划分以得到预测块：所述当前编码单元的宽和高的比值小于P，其中，P为正整数；或所述当前编码单元的最大边长等于预设的阈值；
    在确定允许对所述当前编码单元进行划分以得到预测块的情况下，才执行所述获取所述当前编码单元的预测划分方式。
  12. 一种图像重建装置，其特征在于，包括：
    获取单元，用于获取当前编码单元的预测模式，和/或，获取所述当前编码单元的预测划分方式，所述当前编码单元包括亮度编码块和色度编码块，所述预测划分方式为将所述当前编码单元划分成预测块或预测单元的方式；
    处理单元，用于根据所述预测划分方式和/或所述预测模式，得到所述当前编码单元的变换块；
    重构单元，用于根据所述变换块，产生所述当前编码单元的重构图像块。
  13. 根据权利要求12所述的装置，其特征在于，所述处理单元具体用于：根据所述预测划分方式和/或所述预测模式，将所述当前编码单元划分成变换块。
  14. 根据权利要求12或13所述的装置，其特征在于，所述获取单元具体用于：从码流中解析或推导得到所述预测模式，所述预测模式包括帧内预测模式和帧间预测模式。
  15. 根据权利要求12至14中任一项所述的装置，其特征在于，所述获取单元具体用于：根据所述当前编码单元的尺寸，确定所述当前编码单元允许使用的候选预测划分方式；从所述允许使用的候选预测划分方式中确定出所述预测划分方式。
  16. 根据权利要求12至15中任一项所述的装置，其特征在于，所述获取单元具体用于：根据所述当前编码单元的尺寸，确定所述当前编码单元所述预测划分方式。
  17. 根据权利要求12至16中任一项所述的装置，其特征在于，所述处理单元还用于：在所述预测模式为帧内预测模式的情况下，使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，不对所述色度编码块进行划分，并将所述色度编码块作为色度预测块。
  18. 根据权利要求12至16中任一项所述的装置，其特征在于，所述处理单元还用于： 在所述预测模式为帧间预测模式的情况下，不对所述当前编码单元进行划分，并将所述当前编码单元作为预测单元。
  19. 根据权利要求12至18中任一项所述的装置，其特征在于，所述处理单元还用于：在所述预测模式为帧间预测模式的情况下，按照以下任一种方式对所述当前编码单元进行划分：
    使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，使用所述预测划分方式对所述色度编码块进行划分，得到色度预测块；或
    使用所述预测划分方式对所述亮度编码块进行划分，得到亮度预测块，在所述亮度预测块为两个、且所述两个亮度预测块中至少一个亮度预测块的至少一边的长为4的情况下，不对所述色度编码块进行划分，并将所述色度编码块作为色度预测块。
  20. 根据权利要求12至19中任一项所述的装置，其特征在于，所述处理单元具体用于：在所述预测模式为帧内预测模式，且所述亮度编码块的所述预测划分方式为竖直四等分或非对称竖直二分的情况下，使用竖直四等分对所述亮度编码块进行划分，得到亮度变换块，不对所述色度编码块进行划分，并将色度编码块作为色度变换块；或
    在所述预测模式为帧内预测模式，且所述亮度编码块的所述预测划分方式为水平四等分或非对称水平二分的情况下，使用水平四等分对所述亮度编码块进行划分，得到亮度变换块，不对所述色度编码块进行划分，并将色度编码块作为色度变换块。
  21. 根据权利要求12至19中任一项所述的装置，其特征在于，所述处理单元具体用于：在所述预测模式为帧间预测模式的情况下，不对所述当前编码单元进行划分，并将所述当前编码单元作为变换单元。
  22. 根据权利要求12至21中任一项所述的装置，其特征在于，所述处理单元还用于：在所述当前编码单元的尺寸满足以下至少一个条件的情况下，确定是否允许对所述当前编码单元进行划分以得到预测块：所述当前编码单元的宽和高的比值小于P，其中，P为正整数；或所述当前编码单元的最大边长等于预设的阈值；
    在确定允许对所述当前编码单元进行划分以得到预测块的情况下，才执行所述获取所述当前编码单元的预测划分方式。
  23. 一种视频编解码设备，包括：
    存储器；
    处理器，所述处理器调用存储在所述存储器中的程序代码以执行如权利要求1-11中任一项所述的方法。
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