Deblocking filter parameter signaling

Abstract

A video encoder can signal a set of values for one or more deblocking filter parameters in a high-level parameter set. A video decoder can receive and decode the set of values. The video encoder can also encode an index to the set of values at a lower level. The video decoder can decode the index and then use the index to determine a particular value from the set of values to determine the deblocking filter parameters.

Description

[0001] This application claims priority to U.S. Application No. 17 / 122,850, filed December 15, 2020, and U.S. Provisional Application No. 62 / 705,946, filed July 23, 2020, each of which is incorporated herein by reference in its entirety. U.S. Application No. 17 / 122,850, filed December 15, 2020, claims the benefit of U.S. Provisional Application No. 62 / 705,946, filed July 23, 2020. Technical Field

[0002] This disclosure relates to video encoding and video decoding. Background Technology

[0003] Digital video capabilities can be integrated into a wide range of devices, including digital televisions, digital direct broadcasting systems, wireless broadcasting systems, personal digital assistants (PDAs), laptops or desktop computers, tablets, e-book readers, digital cameras, digital recording devices, digital media players, video game devices, video game consoles, cellular or satellite radio phones (so-called "smartphones"), video conferencing equipment, video streaming devices, and more. Digital video devices implement video codec technologies, such as those described in the standards defined by MPEG-2, MPEG-4, ITU-T H.263, ITU-T H.264 / MPEG-4 Part 10, Advanced Video Codec (AVC), ITU-T H.265 / High-Efficiency Video Codec (HEVC), and extensions to these standards. By implementing such video codec technologies, video devices can more efficiently transmit, receive, encode, decode, and / or store digital video information.

[0004] Video coding and decoding techniques include spatial (intra-picture) prediction and / or temporal (inter-picture) prediction to reduce or eliminate redundancy inherent in video sequences. For block-based video coding and decoding, video strips (e.g., video pictures or portions of video pictures) can be segmented into video blocks, which may also be referred to as codec tree units (CTUs), codec units (CUs), and / or codec nodes. Video blocks in an intra-frame coding (I) strip of a picture are encoded using spatial prediction about reference samples in adjacent blocks within the same picture. Video blocks in an inter-frame coding (P or B) strip of a picture can use spatial prediction about reference samples in adjacent blocks within the same picture, or temporal prediction about reference samples in other reference pictures. A picture may be referred to as a frame, and a reference picture may be referred to as a reference frame. Summary of the Invention

[0005] Generally, this disclosure describes techniques for deblocking filtering, including techniques for signaling parameters of the deblocking filter. In some exemplary video codecs, the deblocking filter can be adapted to local content in a sequence and / or in a picture (e.g., at the tile, strip, or block level). Thus, some exemplary video codecs can signal a set of deblocking filter parameters at different levels (e.g., picture level, strip level, block level, etc.). Signaling such deblocking filter parameters at multiple different levels improves the quality and adaptability of the deblocking filter, at the cost of higher signaling overhead.

[0006] To address this issue, this disclosure describes a technique for signaling a set of values ​​(e.g., multiple values) for one or more deblocking filter parameters at a high-level parameter set (e.g., a picture parameter set, a sequence parameter set, a video parameter set, and / or an adaptive parameter set). A video decoder can receive the parameter set in an encoded video bitstream and decode the set of values. A video encoder can then encode an index of the set of values ​​at a lower level (e.g., at a picture, subpicture, slice, slice group, strip, or block). The video decoder can decode this index and then use it to determine specific values ​​based on the set of values ​​to determine the deblocking filter parameters. In this way, the adaptability of the deblocking filter is maintained while reducing signaling overhead.

[0007] In one example, the method includes: decoding a set of values ​​in a parameter set related to the deblocking filter parameter; determining the value of the deblocking filter parameter based on the set of values; and applying the deblocking filter to video data based on the value of the deblocking filter parameter.

[0008] In another example, the device includes a memory and one or more processors communicating with the memory, the one or more processors being configured to: decode a set of values ​​in a parameter set related to the deblocking filter parameters; determine the value of the deblocking filter parameters based on the set of values; and apply the deblocking filter to video data based on the value of the deblocking filter parameters.

[0009] In another example, the device includes: components for decoding a set of values ​​in a parameter set related to the deblocking filter parameters; components for determining the values ​​of the deblocking filter parameters based on the set of values; and components for applying the deblocking filter to video data based on the values ​​of the deblocking filter parameters.

[0010] In another example, the computer-readable storage medium is encoded with instructions that, when executed, cause a programmable processor to: decode a set of values ​​in a parameter set related to the deblocking filter parameters; determine the value of the deblocking filter parameters based on the set of values; and apply the deblocking filter to the video data based on the value of the deblocking filter parameters.

[0011] In another example, the device includes a memory and one or more processors communicating with the memory, the one or more processors being configured to: encode a set of values ​​in the parameter set relating to a deblocking filter parameter; determine the value of the deblocking filter parameter based on a set of values ​​for a specific block relating to the parameter set; and encode an index to a set of values ​​that can be used to determine the value of the deblocking filter parameter for a specific block.

[0012] Details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the specification, drawings, and claims. Attached Figure Description

[0013] Figure 1 This is a block diagram illustrating an exemplary video encoding and decoding system that can perform the techniques of this disclosure.

[0014] Figure 2A and Figure 2B This is a conceptual diagram illustrating an exemplary quadtree binary tree (QTBT) structure and its corresponding codec tree unit (CTU).

[0015] Figure 3 This is a block diagram illustrating an exemplary video encoder that can perform the techniques of this disclosure.

[0016] Figure 4 This is a block diagram illustrating an exemplary video decoder that can perform the techniques of this disclosure.

[0017] Figure 5 This is a flowchart illustrating an exemplary method for encoding the current block according to the technology of this disclosure.

[0018] Figure 6 This is a flowchart illustrating an exemplary method for decoding the current block according to the technology of this disclosure.

[0019] Figure 7 This is a flowchart illustrating another exemplary method for decoding the current block according to the technology of this disclosure. Detailed Implementation

[0020] Generally, this disclosure describes techniques for deblocking filtering, including techniques for signaling parameters of the deblocking filter. In some exemplary video codecs, the deblocking filter may be adapted to local content in a sequence and / or in a picture (e.g., at the slice, strip, or block level). Therefore, some exemplary video codecs may signal a set of deblocking filter parameters at different levels (e.g., picture level, strip level, block level, etc.). Signaling such deblocking filter parameters at multiple different levels improves the quality and adaptability of deblocking filtering, at the cost of higher signaling overhead.

[0021] To address this issue, this disclosure describes a technique for signaling a set of values ​​(e.g., multiple values) for one or more deblocking filter parameters at a high-level parameter set (e.g., a picture parameter set, a sequence parameter set, a video parameter set, and / or an adaptive parameter set). A video decoder can receive the parameter set in an encoded video bitstream and decode the set of values. A video encoder can then encode indices of the set of values ​​at a lower level (e.g., at a picture, subpicture, slice group, strip, or block). The video decoder can decode these indices and then use them to determine specific values ​​from the set of values ​​to determine the deblocking filter parameters. In this way, the adaptability of the deblocking filter is maintained while reducing signaling overhead.

[0022] Figure 1 This is a block diagram illustrating an exemplary video encoding and decoding system 100 capable of implementing the techniques of this disclosure. The techniques of this disclosure generally relate to encoding and / or decoding video data. Typically, video data includes any data used for processing video. Thus, video data can include raw, unencoded video, encoded video, decoded (e.g., reconstructed) video, and video metadata, such as signaling data.

[0023] like Figure 1 As shown, in this example, system 100 includes a source device 102 that provides encoded video data to be decoded and displayed by destination device 116. Specifically, source device 102 provides the video data to destination device 116 via computer-readable medium 110. Source device 102 and destination device 116 can include any of a variety of devices, including desktop computers, laptops, mobile devices, tablets, set-top boxes, mobile phones (such as smartphones), televisions, cameras, display devices, digital media players, video game consoles, video streaming devices, broadcast receiver devices, etc. In some cases, source device 102 and destination device 116 may be equipped for wireless communication and therefore may be referred to as wireless communication devices.

[0024] exist Figure 1In the example, source device 102 includes a video source 104, memory 106, video encoder 200, and output interface 108. Destination device 116 includes an input interface 122, video decoder 300, memory 120, and display device 118. According to this disclosure, the video encoder 200 of source device 102 and the video decoder 300 of destination device 116 can be configured to apply techniques for deblocking filtering. Thus, source device 102 represents an example of a video encoding device, while destination device 116 represents an example of a video decoding device. In other examples, the source and destination devices may include other components or arrangements. For example, source device 102 may receive video data from an external video source such as an external camera. Similarly, destination device 116 may interface with an external display device, rather than including an integrated display device.

[0025] like Figure 1 The system 100 shown is merely an example. Typically, any digital video encoding and / or decoding device can perform techniques for deblocking filtering. Source device 102 and destination device 116 are simply examples of such encoding / decoding devices, where source device 102 generates encoded / decoded video data for transmission to destination device 116. This disclosure refers to "encoding / decoding" devices as devices that perform the encoding and / or decoding of data. Thus, video encoder 200 and video decoder 300 represent examples of encoding / decoding devices, specifically a video encoder and a video decoder, respectively. In some examples, source device 102 and destination device 116 may operate in a substantially symmetrical manner, such that each of source device 102 and destination device 116 includes video encoding and decoding components. Therefore, system 100 can, for example, support one-way or two-way video transmission between source device 102 and destination device 116 for video streaming, video playback, video broadcasting, or video telephony.

[0026] Typically, video source 104 represents the source of video data (i.e., raw, unencoded video data) and provides a continuous series of pictures (also referred to as "frames") of video data to video encoder 200, which encodes the data of the pictures. Video source 104 of source device 102 may include video capture devices such as cameras, video archives containing previously captured raw video, and / or video feed interfaces that receive video from video content providers. As a further alternative, video source 104 may generate computer graphics-based data as source video, or a combination of live video, archived video, and computer-generated video. In each case, video encoder 200 encodes the captured, pre-captured, or computer-generated video data. Video encoder 200 may rearrange the pictures from the order of receipt (sometimes referred to as "display order") into an encoding / decoding order for encoding and decoding. Video encoder 200 may generate a bitstream comprising encoded video data. The source device 102 can then output encoded video data to a computer-readable medium 110 via the output interface 108 for reception and / or retrieval by, for example, the input interface 122 of the destination device 116.

[0027] The memory 106 of source device 102 and the memory 120 of destination device 116 represent general-purpose memory. In some examples, memories 106 and 120 may store raw video data (e.g., raw video from video source 104) and raw decoded video data from video decoder 300. Alternatively or additionally, memories 106 and 120 may store software instructions executable by, for example, video encoder 200 and video decoder 300. Although memories 106 and 120 are shown separately from video encoder 200 and video decoder 300 in this example, it should be understood that video encoder 200 and video decoder 300 may also include internal memory for functionally similar or equivalent purposes. Furthermore, memories 106 and 120 may store encoded video data, such as data output from video encoder 200 and input to video decoder 300. In some examples, portions of memories 106 and 120 may be allocated as one or more video buffers, for example, to store raw, decoded, and / or encoded video data.

[0028] Computer-readable medium 110 can represent any type of medium or device capable of transmitting encoded video data from source device 102 to destination device 116. In one example, computer-readable medium 110 represents a communication medium that enables source device 102 to transmit encoded video data to destination device 116 in real time, for example, via a radio frequency network or a computer-based network. Depending on the communication standard, such as a wireless communication protocol, output interface 108 can modulate the transmitted signal including the encoded video data, and input interface 122 can demodulate the received transmitted signal. The communication medium can include any wireless or wired communication medium, such as radio frequency (RF) spectrum or one or more physical transmission lines. The communication medium can form part of a packet-based network, such as a local area network, a wide area network, or a global network (such as the Internet). The communication medium can include a router, switch, base station, or any other equipment that facilitates communication from source device 102 to destination device 116.

[0029] In some examples, source device 102 can output encoded data to storage device 112 from output interface 108. Similarly, destination device 116 can access encoded data from storage device 112 via input interface 122. Storage device 112 may include any of a variety of distributed or locally accessed data storage media, such as hard disks, Blu-ray discs, DVDs, CD-ROMs, flash memory, volatile or non-volatile memory, or any other suitable digital storage medium for storing encoded video data.

[0030] In some examples, source device 102 may output encoded video data to file server 114 or another intermediate storage device that may store the encoded video generated by source device 102. Destination device 116 may access the stored video data from file server 114 via streaming or download.

[0031] File server 114 can be any type of server device capable of storing encoded video data and sending the encoded video data to destination device 116. File server 114 can represent a web server (e.g., for a website), a server configured to provide file transfer protocol services (such as File Transfer Protocol (FTP) or One-Way Transfer File Delivery (FLUTE) protocol), a Content Delivery Network (CDN) device, a Hypertext Transfer Protocol (HTTP) server, a Multimedia Broadcast Multicast Service (MBMS) or Enhanced MBMS (eMBMS) server, and / or a Network Attached Storage (NAS) device. File server 114 may additionally or alternatively implement one or more HTTP streaming protocols, such as HTTP-based Dynamic Adaptive Streaming (DASH), HTTP Live Streaming (HLS), Real-Time Streaming Protocol (RTSP), HTTP Dynamic Streaming, etc.

[0032] Destination device 116 can access encoded video data from file server 114 via any standard data connection, including an internet connection. This can include wireless channels (e.g., Wi-Fi connections), wired connections (e.g., digital subscriber line (DSL), cable modems, etc.), or combinations thereof, adapted to access encoded video data stored on file server 114. Input interface 122 can be configured to operate according to any one or more of the various protocols described above for retrieving or receiving media data from file server 114, or other such protocols for retrieving media data.

[0033] Output interface 108 and input interface 122 may represent a wireless transmitter / receiver, a modem, a wired network component (e.g., an Ethernet card), a wireless communication component operating according to any of the various IEEE 802.11 standards, or other physical components. In examples where output interface 108 and input interface 122 include wireless components, output interface 108 and input interface 122 may be configured to transmit data such as encoded video data according to cellular communication standards such as 4G, 4G-LTE (Long Term Evolution), LTE Advanced, 5G, or similar standards. In some examples where output interface 108 includes a wireless transmitter, output interface 108 and input interface 122 may be configured according to other wireless standards, such as the IEEE 802.11 specification, the IEEE 802.15 specification (e.g., ZigBee). TM ),Bluetooth TMThe source device 102 and / or destination device 116 may each include a system-on-a-chip (SoC) device. For example, source device 102 may include an SoC device performing functions belonging to video encoder 200 and / or output interface 108, and destination device 116 may include an SoC device performing functions belonging to video decoder 300 and / or input interface 122.

[0034] The technology disclosed herein can be applied to video encoding and decoding to support any of a variety of multimedia applications, such as over-the-air television broadcasting, cable television transmission, satellite television transmission, internet streaming video transmission (such as Dynamic Adaptive Streaming (DASH) via HTTP), digital video encoded onto a data storage medium, decoding of digital video stored on a data storage medium, or other applications.

[0035] The input interface 122 of the destination device 116 receives an encoded video bitstream from a computer-readable medium 110 (e.g., a communication medium, storage device 112, file server 114, etc.). The encoded video bitstream may include signaling information defined by the video encoder 200, which is also used by the video decoder 300, such as syntax elements having values ​​describing the characteristics and / or processing of video blocks or other encoded / decoded units (e.g., stripes, picture groups, sequences, etc.). The display device 118 displays decoded images of the decoded video data to the user. The display device 118 may represent any of a variety of display devices, such as a liquid crystal display (LCD), a plasma display, an organic light-emitting diode (OLED) display, or another type of display device.

[0036] Although not in Figure 1 As shown, but in some examples, each of the video encoder 200 and video decoder 300 may be integrated with the audio encoder and / or audio decoder, and may include appropriate MUX-DEMUX units or other hardware and / or software to process multiplexed streams of audio and video in a common data stream. Where applicable, the MUX-DEMUX unit may conform to the ITU H.223 multiplexer protocol, or other protocols such as User Datagram Protocol (UDP).

[0037] The video encoder 200 and video decoder 300 can each be implemented as any of a variety of suitable encoder and / or decoder circuits, such as one or more microprocessors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), discrete logic, software, hardware, firmware, or any combination thereof. When the technology is partially implemented in software, the device may store instructions for software in a suitable non-transitory computer-readable medium and use one or more processors to execute those instructions in hardware to perform the technology of this disclosure. Each of the video encoder 200 and video decoder 300 may be included in one or more encoders or decoders, either of which may be integrated as part of a combined encoder / decoder (codec (CODEC)) in the respective device. Devices including the video encoder 200 and / or video decoder 300 may include integrated circuits, microprocessors, and / or wireless communication devices, such as cellular phones.

[0038] The video encoder 200 and video decoder 300 can operate according to video codec standards such as ITU-TH.265, also known as High Efficiency Video Coding (HEVC) or its extensions such as Multi-View and / or Scalable Video Coding Extensions. Alternatively, the video encoder 200 and video decoder 300 can operate according to other proprietary or industry standards such as ITU-TH.266, also known as Versatile Video Coding (VVC). A draft of the VVC standard is described below: “Versatile Video Coding (Draft 10)” by Bross et al., ITU-T SG 16WP 3 and ISO / IEC JTC1 / SC 29 / WG 11, 18th meeting (teleconference): June 22-July 1, 2020, JVET-S2001-vA (hereinafter referred to as “VVC Draft 10”). However, the technology disclosed herein is not limited to any particular codec standard.

[0039] Typically, video encoder 200 and video decoder 300 can perform block-based encoding and decoding of images. The term "block" generally refers to a structure that includes data to be processed (e.g., encoded, decoded, or otherwise used in the encoding and / or decoding process). For example, a block may include a two-dimensional matrix of samples of luminance and / or chrominance data. Typically, video encoder 200 and video decoder 300 can encode and decode video data represented in YUV (e.g., Y, Cb, Cr) format. That is, video encoder 200 and video decoder 300 can encode and decode luminance and chrominance components, rather than encoding and decoding red, green, and blue (RGB) data of samples used for images, where chrominance components may include both red and blue chrominance components. In some examples, video encoder 200 converts received RGB formatted data to YUV representation before encoding, and video decoder 300 converts the YUV representation to RGB format. Alternatively, preprocessing and post-processing units (not shown) can perform these conversions.

[0040] This disclosure can generally relate to the encoding and decoding (e.g., encoding and decoding) of images to include processes for encoding or decoding image data. Similarly, this disclosure can relate to the encoding and decoding of blocks of images to include processes for encoding or decoding data for blocks, such as prediction and / or residual encoding and decoding. Encoded video bitstreams typically include a series of values ​​for syntax elements representing encoding and decoding decisions (e.g., encoding and decoding modes) and the segmentation of images into blocks. Therefore, references to encoded or decoded images or blocks should generally be understood as encoding and decoding values ​​of syntax elements used to form images or blocks.

[0041] HEVC defines various blocks, including Codec Units (CUs), Prediction Units (PUs), and Transform Units (TUs). According to HEVC, a video codec (such as a video encoder 200) partitions a Codec Unit (CTU) into CUs based on a quadtree structure. That is, the video codec partitions the CTU and CU into four equal, non-overlapping squares, and each node of the quadtree has zero or four child nodes. Nodes without child nodes can be called "leaf nodes," and the CU of this leaf node can include one or more PUs and / or one or more TUs. The video codec can also partition PUs and TUs. For example, in HEVC, a Residual Quadtree (RQT) represents a partition of a TU. In HEVC, a PU represents inter-frame prediction data, while a TU represents residual data. Intra-frame prediction CUs include intra-frame prediction information, such as intra-frame mode indications.

[0042] As another example, video encoder 200 and video decoder 300 can be configured to operate according to VVC. According to VVC, the video codec (such as video encoder 200) segments the image into multiple codec tree units (CTUs). Video encoder 200 can segment CTUs according to a tree structure, such as a quadtree-binary tree (QTBT) structure or a multi-type tree (MTT) structure. The QTBT structure removes the concept of multiple segmentation types, such as the separation between CUs, PUs, and TUs in HEVC. The QTBT structure includes two levels: a first level segmented according to quadtree segmentation and a second level segmented according to binary tree segmentation. The root node of the QTBT structure corresponds to a CTU. The leaf nodes of the binary tree correspond to codec units (CUs).

[0043] In an MTT partitioning structure, blocks can be partitioned using quadtree (QT), binary tree (BT), and one or more types of triple tree (TT) partitioning (also known as ternary tree (TT)). A triple tree or ternary tree partition is a partition that divides a block into three sub-blocks. In some examples, a triple tree or ternary tree partition divides a block into three sub-blocks without using a center to divide the original block. The partitioning type in an MTT (e.g., QT, BT, and TT) can be symmetric or asymmetric.

[0044] In some examples, the video encoder 200 and the video decoder 300 may use a single QTBT or MTT structure to represent each of the luma and chroma components, while in other examples, the video encoder 200 and the video decoder 300 may use two or more QTBT or MTT structures, such as one QTBT / MTT structure for the luma component and another QTBT / MTT structure for the two chroma components (or two QTBT / MTT structures for the respective chroma components).

[0045] The video encoder 200 and video decoder 300 can be configured to use per-HEVC quadtree segmentation, QTBT segmentation, or MTT segmentation or other segmentation structures. For illustrative purposes, the description of the techniques of this disclosure is presented in relation to QTBT segmentation. However, it should be understood that the techniques of this disclosure can also be applied to video codecs configured to use quadtree segmentation or other types of segmentation.

[0046] In some examples, a CTU includes a codec tree block (CTB) of luma samples, two corresponding CTBs of chroma samples from an image with three sample arrays, or a CTB of samples from a monochrome image or an image encoded using three separate color planes and syntax structures for encoding and decoding the samples. A CTB can be an N×N sample block of some value of N, such that dividing the components into CTBs is a partition. A component is an array or a single sample from one of the three arrays (luma and two chroma) constituting an image in a 4:2:0, 4:2:2, or 4:4:4 color format, or an array or a single sample from an array constituting an image in monochrome format. In some examples, a codec block is an M×N sample block of some values ​​of M and N, such that dividing the CTB into codec blocks is a partition.

[0047] Blocks (e.g., CTUs or CUs) can be grouped in various ways within an image. As an example, a brick can refer to a rectangular area of ​​a row of CTUs within a specific tile in an image. A tile can be a rectangular area of ​​CTUs within a specific tile column or a specific tile row in an image. A tile column is a rectangular area of ​​CTUs whose height is equal to the image height, and whose width is specified by syntax elements (e.g., in an image parameter set). A tile row represents a rectangular area of ​​CTUs whose height is specified by syntax elements (e.g., in an image parameter set), and whose width is equal to the image width.

[0048] In some examples, a slice can be divided into multiple bricks, each brick potentially including one or more CTU rows within the slice. A slice that is not divided into multiple bricks can also be referred to as a brick. However, bricks that are a true subset of a slice may not be referred to as a slice.

[0049] The bricks in an image can also be arranged into strips. A strip can be an integer number of image bricks that can be exclusively contained in a single Network Abstraction Layer (NAL) unit. In some examples, a strip consists of multiple complete slices or a continuous sequence of complete bricks consisting of only one slice.

[0050] This disclosure uses "N×N" and "N multiplied by N" interchangeably to represent the sample size of a block (such as a CU or other video block) in the vertical and horizontal dimensions, for example, 16×16 samples or 16 by 16 samples. Typically, a 16×16 CU has 16 samples in the vertical direction (y = 16) and 16 samples in the horizontal direction (x = 16). Similarly, an N×N CU typically has N samples in the vertical direction and N samples in the horizontal direction, where N represents a non-negative integer value. Samples in a CU can be arranged in rows and columns. Furthermore, a CU does not necessarily need to have the same number of samples in the horizontal direction as in the vertical direction. For example, a CU can include N×M samples, where M is not necessarily equal to N.

[0051] The video encoder 200 encodes video data representing prediction and / or residual information, as well as other information, for the CU (Cumulative Unit). Prediction information indicates how the CU should be predicted to form a prediction block for the CU. Residual information typically represents the point-by-point difference between the CU samples before encoding and the prediction block.

[0052] To predict the Cues (CUs), the video encoder 200 typically forms prediction blocks for the CUs using either inter-frame prediction or intra-frame prediction. Inter-frame prediction generally refers to predicting the CU from data of a previously encoded / decoded image, while intra-frame prediction generally refers to predicting the CU from data of a previously encoded / decoded image of the same image. To perform inter-frame prediction, the video encoder 200 can use one or more motion vectors to generate prediction blocks. The video encoder 200 can typically perform a motion search to identify reference blocks that closely match the CU, for example, in terms of the difference between the CU and a reference block. The video encoder 200 can use sum of absolute differences (SAD), sum of squared differences (SSD), mean absolute difference (MAD), mean squared difference (MSD), or other such difference calculations to compute difference metrics to determine whether a reference block closely matches the current CU. In some examples, the video encoder 200 can use unidirectional or bidirectional prediction to predict the current CU.

[0053] Some examples of VVC also offer an affine motion compensation mode, which can be considered an inter-frame prediction mode. In affine motion compensation mode, the video encoder 200 can determine two or more motion vectors representing non-translational motion, such as zoom in or out, rotation, perspective motion, or other irregular motion types.

[0054] To perform intra-frame prediction, the video encoder 200 can select an intra-frame prediction mode to generate prediction blocks. Some examples of VVC provide sixty-seven intra-frame prediction modes, including modes for various orientations, as well as planar and DC modes. Typically, the video encoder 200 selects an intra-frame prediction mode that describes the neighboring samples of the current block (e.g., a block of a CU) to predict the prediction samples of the current block from them. Assuming the video encoder 200 encodes and decodes CTUs and CUs in raster scan order (from left to right, from top to bottom), such samples are typically located above, above to left, or to the left of the current block in the same frame as the current block.

[0055] The video encoder 200 encodes data representing the prediction mode of the current block. For example, for inter-frame prediction modes, the video encoder 200 may encode data indicating which of the various available inter-frame prediction modes is used, as well as motion information for the corresponding mode. For unidirectional or bidirectional inter-frame prediction, for example, the video encoder 200 may use Advanced Motion Vector Prediction (AMVP) or merging modes to encode motion vectors. The video encoder 200 may use similar modes to encode motion vectors for affine motion compensation modes.

[0056] Following prediction, such as intra-frame or inter-frame prediction of a block, the video encoder 200 can compute residual data for the block. The residual data (such as a residual block) represents the sample-by-sample difference between the block and the predicted block for that block, formed by using the corresponding prediction mode. The video encoder 200 can apply one or more transforms to the residual block to produce transformed data in the transform domain rather than the sample domain. For example, the video encoder 200 can apply a Discrete Cosine Transform (DCT), integer transform, wavelet transform, or conceptually similar transforms to the residual video data. Additionally, the video encoder 200 can apply a second transform after the first transform, such as a Mode-dependent Inseparable Quadratic Transform (MDNSST), a Signal-dependent Transform, a Karhunen-Loeve Transform (KLT), etc. The video encoder 200 generates transform coefficients after applying one or more transforms.

[0057] As described above, after any transform that produces the transform coefficients, the video encoder 200 can perform quantization of the transform coefficients. Quantization generally refers to the process in which transform coefficients are quantized to minimize the amount of data used to represent the coefficients, thereby providing further compression. By performing the quantization process, the video encoder 200 can reduce the bit depth associated with some or all of the coefficients. For example, the video encoder 200 can round an n-bit value to an m-bit value during quantization, where n is greater than m. In some examples, to perform quantization, the video encoder 200 can perform a bit-by-bit right shift of the value to be quantized.

[0058] After quantization, the video encoder 200 can scan the transform coefficients to generate a one-dimensional vector from a two-dimensional matrix including the quantized transform coefficients. The scan can be designed to place higher-energy (and therefore lower-frequency) coefficients before the vector and lower-energy (and therefore higher-frequency) transform coefficients after the vector. In some examples, the video encoder 200 can scan the quantized transform coefficients using a predetermined scan order to produce a serialized vector, and then entropy-encode the quantized transform coefficients of the vector. In other examples, the video encoder 200 can perform an adaptive scan. After scanning the quantized transform coefficients to form a one-dimensional vector, the video encoder 200 can entropy-encode the one-dimensional vector, for example, according to context-adaptive binary arithmetic codec (CABAC). The video encoder 200 can also entropy-encode the values ​​of syntax elements used to describe metadata associated with the encoded video data for use by the video decoder 300 when decoding the video data.

[0059] To perform CABAC, the video encoder 200 can assign context within a context model to the symbols to be transmitted. The context may involve, for example, whether the neighboring values ​​of a symbol are zero. Probability determination can be based on the context assigned to the symbol.

[0060] The video encoder 200 can also generate syntax data for the video decoder 300, such as block-based syntax data, image-based syntax data, and sequence-based syntax data, in image headers, block headers, stripe headers, or other syntax data (such as sequence parameter sets (SPS), picture parameter sets (PPS), or video parameter sets (VPS)). The video decoder 300 can similarly decode such syntax data to determine how to decode the corresponding video data.

[0061] In this way, the video encoder 200 can generate a bitstream that includes encoded video data, such as syntax elements describing the segmentation of images into blocks (e.g., CUs) and prediction and / or residual information for the blocks. Finally, the video decoder 300 can receive the bitstream and decode the encoded video data.

[0062] Typically, the video decoder 300 performs a process reciprocal to that performed by the video encoder 200 to decode the encoded video data of the bitstream. For example, the video decoder 300 can use CABAC in a manner substantially similar to, but reciprocal to, the CABAC encoding process of the video encoder 200 to decode the values ​​for syntax elements in the bitstream. Syntax elements can define segmentation information used to segment the image into CTUs and to segment each CTU according to a corresponding segmentation structure such as a QTBT structure to define the CUs of the CTUs. Syntax elements can also define prediction and residual information for blocks (e.g., CUs) of the video data.

[0063] The residual information can be represented, for example, by quantized transform coefficients. The video decoder 300 can inversely quantize and inversely transform the quantized transform coefficients of the block to reconstruct the residual block of the block. The video decoder 300 uses the prediction mode (intra-frame prediction or inter-frame prediction) notified by signaling and relevant prediction information (e.g., motion information for inter-frame prediction) to form a prediction block for the block. The video decoder 300 can then combine the prediction block and the residual block (on a sample-by-sample basis) to reconstruct the original block. The video decoder 300 can perform additional processing, such as performing a deblocking process to reduce visual artifacts along the block boundaries.

[0064] This disclosure may generally relate to "signaling notification" of some kind of information, such as syntax elements. The term "signaling notification" can generally refer to the communication used to decode values ​​for syntax elements and / or other data in encoded video data. That is, the video encoder 200 may signal the value for a syntax element in the bitstream. Typically, signaling notification refers to generating a value in the bitstream. As described above, the source device 102 may transmit the bitstream to the destination device 116 substantially in real time (or non-real time, such as when storing syntax elements to storage device 112 for later retrieval by the destination device 116).

[0065] According to the technology disclosed herein, video encoder 200 and video decoder 300 are configured to encode and decode a set of values ​​for one or more deblocking filter parameters. As will be explained in more detail below, video encoder 200 may be configured to encode a set of values ​​for deblocking filter parameters in a parameter set and to signal the parameter set in the encoded video bitstream. Video decoder 300 may be configured to receive the parameter set in the encoded video bitstream, decode the set of values ​​in the parameter set associated with the deblocking filter parameters, determine the values ​​of the deblocking filter parameters based on the value set, and apply a deblocking filter to the video data based on the values ​​of the deblocking filter parameters.

[0066] In some exemplary video codec standards such as HEVC and VVC, deblocking filter parameters such as the deblocking filter threshold offset (betaOffset) and the limiting offset (TcOffset) are signaled in a layered manner. The video decoder 300 can use the values ​​of betaOffset and TcOffset to determine the deblocking filter parameters beta(β) and Tc, respectively. The video encoder 200 and the video decoder 300 can use the deblocking filter threshold β to control the manner of deblocking, such as whether to deblock a segment, whether to use strong deblocking or normal deblocking, and / or whether to process one or two samples on one side of the segment. The video encoder 200 and the video decoder 300 can use the limiting value Tc to control the maximum variation in sample amplitude.

[0067] In some examples, the video encoder 200 can signal in the Picture Parameter Set (PPS) to notify the betaOffset and TcOffset for each component. The PPS can be referenced by several pictures. In the Picture Header (PH) that can be used by all stripes in the picture, the video encoder 200 can signal new deblocking filter parameters for use when applying the deblocking filter to the picture. When no new deblocking filter parameters are signaled, the video decoder 300 can use the parameters in the referenced PPS when applying the deblocking filter to the picture. In the Strip Header (SH), the video encoder 200 can signal new deblocking filter parameters for use when applying the deblocking filter to the strip. When no new deblocking filter parameters are signaled, the video decoder 300 can use the parameters in the PH or the referenced PPS when applying the deblocking filter to the strip.

[0068] The hierarchical signaling mechanism described above for deblocking filter parameters allows the parameters to adapt to local codec content and features at the picture level and / or stripe level. However, the signaling overhead for such a hierarchical signaling mechanism may not be optimal in all cases and may lead to reduced decoding efficiency. This disclosure describes techniques for improving the efficiency of signaling deblocking filter parameters (including betaOffset and TcOffset) relative to those used in HEVC and VVC. The techniques of this disclosure can reduce signaling overhead and may therefore increase codec efficiency.

[0069] For example, within a group of pictures (GOP), the video encoder 200 can group pictures into several categories based on certain characteristics of the video (such as picture type, strip type, and / or temporal layer index). Pictures and strips within a category can have similar behaviors and characteristics. Thus, the video encoder 200 can select similar encoding / decoding tools and techniques. Consequently, the video encoder 200 might use the same deblocking filter parameters for pictures within the same category. Therefore, signaling the actual parameters for each picture in a category could increase signaling overhead and reduce encoding / decoding efficiency.

[0070] To reduce the signaling overhead of deblocking filter parameters, for one or more deblocking filter parameters (e.g., deblocking filter threshold offset (BetOffset) and / or limiting value offset (TcOffset)), the video encoder 200 can be configured to encode a set of values ​​from a parameter set (PS) (such as a sequence parameter set (SPS), video parameter set (VPS), picture parameter set (PPS), adaptive parameter set (APS), or other parameter sets or headers in the encoded video bitstream) and signal that set of values. For example, the video encoder 200 can signal a first set of values ​​for the deblocking filter threshold offset (betaOffset) and / or a second set of values ​​for the limiting value offset (TcOffset). The video decoder 300 can be configured to receive and decode this set of values ​​for the deblocking filter parameters.

[0071] The video encoder 200 can then encode the index of the value set at a lower level (e.g., at the picture, subpicture, slice, slice group, strip, or block level). The video decoder 300 can decode the index and then use the index to determine specific values ​​from the value set to determine the deblocking filter parameters. In this way, the deblocking filter adaptability is maintained while reducing signaling overhead. In some examples, to determine the final value of the deblocking filter threshold, the video decoder 300 can add the determined deblocking filter threshold offset to a previously signaled notification or a predetermined basic deblocking filter threshold. Similarly, to determine the final value of the limiting value, the video decoder 300 can add the determined limiting value offset to a previously signaled notification or a predetermined basic limiting value.

[0072] Therefore, in one example of this disclosure, the video decoder 300 can be configured to: receive a set of parameters in the encoded video bitstream; decode a set of values ​​in the parameter set related to deblocking filter parameters; determine the values ​​of the deblocking filter parameters based on the set of values; and apply a deblocking filter to the video data based on the values ​​of the deblocking filter parameters. The parameter set can be one or more of a sequence parameter set, a video parameter set, a picture parameter set, or an adaptive parameter set.

[0073] In one example, the deblocking filter parameters include one or more of a deblocking filter threshold offset or a limiting value offset. The video decoder 300 can also be configured to determine a deblocking filter threshold (β) based on the deblocking filter threshold offset (betaOffset) and apply the deblocking filter to the video data using the deblocking filter threshold (β). Similarly, the video decoder 300 can be configured to determine a limiting value (TcOffset) based on the limiting value offset (TcOffset). c ), and use the limiting value (T) c Apply the deblocking filter to the video data.

[0074] In some examples, for individual parameters (e.g., betaOffset or TcOffset), all sets of values ​​may have the same number of values. This number may be fixed, or the video encoder 200 may signal the values ​​at the sequence and / or GOP level. In another example, for all parameters (e.g., betaOffset and TcOffset), all sets of values ​​may have the same number of values. Again, this number may be fixed, or the number may be signaled at the sequence and / or GOP level. In one example, for the set of values ​​for a deblocking filter parameter, the video encoder 200 may first signal the size of the set (e.g., indicating the number of values ​​in the set), and then signal the values ​​in the set.

[0075] When a deblocking filter is applied to a picture or subpicture (e.g., a subpicture can be a slice, strip, slice group, and / or block), the video decoder 300 can obtain the values ​​of the deblocking filter parameters (e.g., betaOffset and TcOffset) of the picture / subpicture from the set of values ​​signaled in the PS that the picture / subpicture is referencing. In one example, the video decoder 300 may implicitly determine the values ​​of the deblocking filter parameters (e.g., betaOffset and / or TcOffset) for the picture or subpicture based on the codec information associated with the picture or subpicture. The codec information associated with the picture or subpicture may include a temporal layer index, codec type (e.g., bidirectional inter-frame, unidirectional inter-frame, or intra-frame), and / or quantization parameters. In this context, implicitly determining the values ​​of the deblocking filter parameters means that the video decoder 300 determines the values ​​of the deblocking filter parameters without receiving or decoding syntax elements that explicitly indicate the values ​​of the deblocking filter parameters.

[0076] In another example, video decoder 300 can determine the values ​​of deblocking filter parameters (e.g., betaOffset and / or TcOffset) for a picture or subpicture by decoding an index that is explicitly signaled. Video decoder 300 can determine the values ​​of the deblocking filter parameters based on values ​​in a set of referenced values ​​in the PS associated with the decoded index.

[0077] In another example, after obtaining initial values ​​for the deblocking filter parameters (e.g., betaOffset and TcOffset) from a set of deblocking filter parameters, the video decoder 300 can also derive offsets (e.g., from other codec information) or offsets that can be received signaled in the encoded video bitstream. The video decoder 300 can then use the offsets and a function of the initial values ​​determined from that set to determine the final values ​​of the deblocking filter parameters (e.g., betaOffset and TcOffset) for use with pictures and / or subpictures.

[0078] In view of the foregoing, in one example of this disclosure, the video decoder 300 may be configured to: decode a set of values ​​for deblocking filter parameters in a parameter set, determine the values ​​of the deblocking filter parameters based on the set of values, and apply a deblocking filter to video data using the values ​​of the deblocking filter parameters. In one example, the deblocking filter parameters include one or more of betaOffset or TcOffset. In one example, the parameter set is one or more of a sequence parameter set, a video parameter set, a picture parameter set, or an adaptive parameter set. In another example, the video decoder 300 may be configured to decode a syntax element indicating the number of values ​​in the set of values ​​for the deblocking filter parameters in the parameter set.

[0079] In another example, the video decoder 300 can be configured to determine the values ​​of the deblocking filter parameters based on the set of values ​​of codec information, wherein the codec information includes one or more of a time layer index, a codec type, or one or more quantization parameters.

[0080] In another example, the video decoder 300 can be configured to decode an index of a value from the set of values ​​that indicates deblocking filter parameters, and to determine the deblocking filter parameters based on that index.

[0081] In another example, the video decoder 300 can be configured to: determine the initial value of the deblocking filter parameters based on the set of values, decode the offset, and determine the deblocking filter parameters by adding the offset to the initial value of the deblocking filter parameters.

[0082] Figure 2A and Figure 2BThis is a conceptual diagram illustrating an exemplary Quadtree Binary Tree (QTBT) structure 130 and a corresponding Code-Decoder Tree Unit (CTU) 132. Solid lines represent quadtree partitions, and dashed lines indicate binary tree partitions. In each partition node (i.e., a non-leaf node) of the binary tree, a flag is signaled to indicate which partition type (i.e., horizontal or vertical) is used, where in this example, 0 indicates a horizontal partition and 1 indicates a vertical partition. For quadtree partitions, it is not necessary to indicate the partition type because the quadtree node divides the block horizontally and vertically into four equal-sized sub-blocks. Accordingly, the video encoder 200 can encode syntax elements (such as partition information) for the region tree level (i.e., solid lines) of the QTBT structure 130 and syntax elements (such as partition information) for the prediction tree level (i.e., dashed lines) of the QTBT structure 130, and the video decoder 300 can decode these syntax elements. The video encoder 200 can be used to encode video data (such as prediction and transform data) of the CU represented by the terminal leaf nodes of the QTBT structure 130, and the video decoder 300 can decode the video data.

[0083] generally, Figure 2B The CTU 132 can be associated with parameters that define the size of the block corresponding to the nodes of the first-level and second-level QTBT structures 130. These parameters may include the CTU size (representing the size of the sampled CTU 132), the minimum quadtree size (MinQTSize, representing the minimum allowed size of a quadtree leaf node), the maximum binary tree size (MaxBTSize, representing the maximum allowed size of a binary tree root node), the maximum binary tree depth (MaxBTDepth, representing the maximum allowed depth of a binary tree), and the minimum binary tree size (MinBTSize, representing the minimum allowed size of a binary tree leaf node).

[0084] The root node of the QTBT structure corresponding to the CTU can have four child nodes at the first level of the QTBT structure, each of which can be partitioned according to a quadtree partition. That is, the node at the first level is either a leaf node (with no child nodes) or has four child nodes. An example of QTBT structure 130 represents such a node as including a parent node and child nodes with solid lines for branching. If the node at the first level is not larger than the maximum allowed binary tree root node size (MaxBTSize), the node can also be partitioned by the corresponding binary tree. The binary tree partitioning of a node can be iterated until the partitioned node reaches the minimum allowed binary tree leaf node size (MinBTSize) or the maximum allowed binary tree depth (MaxBTDepth). An example of QTBT structure 130 represents such a node with dashed lines for branching. The binary tree leaf node is called a codec unit (CU), which is used for prediction (e.g., intra-frame picture prediction or inter-frame picture prediction) and transformation without any further partitioning. As discussed above, the CU can also be referred to as a "video block" or "block".

[0085] In one example of a QTBT partitioning structure, the CTU size is set to 128×128 (luminance samples and two corresponding 64×64 chrominance samples), MinQTSize is set to 16×16, MaxBTSize is set to 64×64, MinBTSize (for width and height) is set to 4, and MaxBTDepth is set to 4. Quadtree partitioning is first applied to the CTU to generate quadtree leaf nodes. Quadtree leaf nodes can have sizes ranging from 16×16 (i.e., MinQTSize) to 128×128 (i.e., the CTU size). If a leaf quadtree node is 128×128, it will not be further partitioned into a binary tree because its size exceeds MaxBTSize (i.e., 64×64 in this example). Otherwise, the leaf quadtree node will be further partitioned into a binary tree. Therefore, the quadtree leaf node is also used as the root node of the binary tree, and the binary tree depth is 0. When the depth of the binary tree reaches MaxBTDepth (4 in this example), further partitioning is not permitted. A binary tree node with a width equal to MinBTSize (4 in this example) means that no further vertical partitioning (i.e., partition width) is permitted for that binary tree node. Similarly, a binary tree node with a height equal to MinBTSize means that no further horizontal partitioning (i.e., partition height) is permitted for that binary tree node. As described above, the leaf nodes of the binary tree are called CUs and are further processed according to the prediction and transformation without further partitioning.

[0086] Figure 3This is a block diagram illustrating an exemplary video encoder 200 capable of performing the techniques of this disclosure. Provided Figure 3 This disclosure is for illustrative purposes and should not be construed as a constraint on the extensive examples and techniques described herein. For illustrative purposes, this disclosure describes a video encoder 200 based on VVC (ITU-T H.266, under development) and HEVC (ITU-T H.265) technologies. However, the techniques of this disclosure can be implemented by video encoding devices configured to other video codec standards.

[0087] exist Figure 3 In the example, the video encoder 200 includes a video data memory 230, a mode selection unit 202, a residual generation 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 filter unit 216, a decoded picture buffer (DPB) 218, and an entropy encoding unit 220. Any one or all of the video data memory 230, mode selection unit 202, residual generation unit 204, transform processing unit 206, quantization unit 208, inverse quantization unit 210, inverse transform processing unit 212, reconstruction unit 214, filter unit 216, DPB 218, and entropy encoding unit 220 can be implemented in one or more processors or processing circuits. For example, the units of the video encoder 200 can be implemented as one or more circuit or logic elements as part of hardware circuitry or as part of a processor ASIC of an FPGA. Furthermore, the video encoder 200 may include additional or alternative processors or processing circuitry to perform these and other functions.

[0088] The video data storage device 230 can store video data to be encoded by the components of the video encoder 200. The video encoder 200 can obtain data from, for example, a video source 104 (…). Figure 1 The video encoder 200 receives video data stored in video data memory 230. DPB 218 can be used as a reference image memory, storing reference video data for use by the video encoder 200 in predicting subsequent video data. Video data memory 230 and DPB 218 can be formed from any of a variety of memory devices, such as dynamic random access memory (DRAM), including synchronous DRAM (SDRAM), magnetoresistive RAM (MRAM), resistive RAM (RRAM), or other types of memory devices. Video data memory 230 and DPB 218 can be provided by the same memory device or separate memory devices. In various examples, video data memory 230 can be on-chip with other components of the video encoder 200, as illustrated, or off-chip relative to those components.

[0089] In this disclosure, references to video data memory 230 should not be construed as limited to memory within video encoder 200 unless specifically described therein, or to memory external to video encoder 200 unless specifically described therein. Rather, references to video data memory 230 should be understood as reference memory storing video data received by video encoder 200 for encoding (e.g., video data of the current block to be encoded). Figure 1 The memory 106 can also provide temporary storage for the outputs of each unit of the video encoder 200.

[0090] Figure 3 The various units are shown to aid in understanding the operations performed by the video encoder 200. These units can be implemented as fixed-function circuits, programmable circuits, or a combination thereof. A fixed-function circuit is a circuit that provides a specific function and is pre-programmed to perform certain operations. A programmable circuit is a circuit that can be programmed to perform various tasks and provides flexible functionality within the operations it can perform. For example, a programmable circuit can run software or firmware that causes it to operate in a manner defined by the instructions of the software or firmware. A fixed-function circuit can run software instructions (e.g., to receive or output parameters), but the type of operation performed by a fixed-function circuit is typically immutable. In some examples, one or more of the units can be different circuit blocks (fixed-function or programmable), and in some examples, one or more units can be integrated circuits.

[0091] The video encoder 200 may include an arithmetic logic unit (ALU), an essential function unit (EFU), digital circuitry, analog circuitry, and / or a programmable core, all formed by programmable circuitry. In an example where the operation of the video encoder 200 is performed using software executed by programmable circuitry, memory 106 ( Figure 1 The video encoder 200 may store instructions (e.g., object code) of the software received and executed by the video encoder 200, or another memory within the video encoder 200 (not shown) may store such instructions.

[0092] The video data storage unit 230 is configured to store received video data. The video encoder 200 can retrieve images of the video data from the video data storage unit 230 and provide the video data to the residual generation unit 204 and the mode selection unit 202. The video data in the video data storage unit 230 can be the raw video data to be encoded.

[0093] The mode selection unit 202 includes a motion estimation unit 222, a motion compensation unit 224, and an intra-frame prediction unit 226. The mode selection unit 202 may include additional functional units to perform video prediction based on other prediction modes. As an example, the mode selection unit 202 may include a palette unit, an intra-frame block copying unit (which may be part of the motion estimation unit 222 and / or the motion compensation unit 224), an affine unit, a linear model (LM) unit, etc.

[0094] The mode selection unit 202 typically coordinates multiple encoding processes to test combinations of encoding parameters and the resulting rate-distortion values ​​for such combinations. Encoding parameters may include the CTU-CU split, the prediction mode for the CU, the transform type for the CU residual data, the quantization parameters for the CU residual data, etc. The mode selection unit 202 can ultimately select a combination of encoding parameters that has a better rate-distortion value than other test combinations.

[0095] The video encoder 200 can segment images retrieved from the video data storage 230 into a series of CTUs and encapsulate one or more CTUs within a strip. The mode selection unit 202 can segment the CTUs of the image according to a tree structure (such as the QTBT structure or quadtree structure of HEVC described above). As mentioned above, the video encoder 200 can form one or more CUs by segmenting CTUs according to a tree structure. Such CUs can also be commonly referred to as "video blocks" or "blocks".

[0096] Typically, mode selection unit 202 also controls its components (e.g., motion estimation unit 222, motion compensation unit 224, and intra-prediction unit 226) to generate predicted blocks for the current block (e.g., the overlapping portion of PU and TU in the current CU or HEVC). To perform inter-frame prediction for the current block, motion estimation unit 222 may perform a motion search to identify one or more closely matching reference blocks in one or more reference pictures (e.g., one or more previously encoded / decoded pictures stored in DPB 218). Specifically, motion estimation unit 222 may calculate values ​​representing how similar a potential reference block is to the current block, for example, based on sum of absolute differences (SAD), sum of squared differences (SSD), mean absolute difference (MAD), mean squared difference (MSD), etc. Motion estimation unit 222 may typically perform these calculations using the sample-by-sample difference between the current block and the reference block under consideration. Motion estimation unit 222 may identify the reference block with the lowest value obtained from these calculations, indicating the reference block that most closely matches the current block.

[0097] Motion estimation unit 222 can generate one or more motion vectors (MVs), which define the position of a reference block in a reference image relative to a current block in the current image. Motion estimation unit 222 can then provide the motion vectors to motion compensation unit 224. For example, for unidirectional inter-frame prediction, motion estimation unit 222 can provide a single motion vector, while for bidirectional inter-frame prediction, motion estimation unit 222 can provide two motion vectors. Motion compensation unit 224 can then use the motion vectors to generate prediction blocks. For example, motion compensation unit 224 can use the motion vectors to retrieve data for the reference blocks. As another example, if the motion vectors have fractional sample precision, motion compensation unit 224 can interpolate values ​​for the prediction blocks according to one or more interpolation filters. Furthermore, for bidirectional inter-frame prediction, motion compensation unit 224 can retrieve data for the two reference blocks identified by the corresponding motion vectors and combine the retrieved data, for example, by sample-by-sample averaging or weighted averaging.

[0098] As another example, for intra-prediction or intra-prediction codec, intra-prediction unit 226 can generate a prediction block based on samples adjacent to the current block. For example, in directional mode, intra-prediction unit 226 can typically mathematically combine the values ​​of adjacent samples and fill these calculated values ​​in a defined direction across the current block to produce a prediction block. As another example, in DC mode, intra-prediction unit 226 can calculate the average of the adjacent samples of the current block and generate a prediction block to include the average obtained for each sample of the prediction block.

[0099] Mode selection unit 202 provides the prediction block to residual generation unit 204. Residual generation unit 204 receives the raw, uncoded version of the current block from video data memory 230 and the prediction block from mode selection unit 202. Residual generation unit 204 calculates the sample-by-sample difference between the current block and the prediction block. The resulting sample-by-sample difference defines the residual block for the current block. In some examples, residual generation unit 204 may also determine the difference between sample values ​​in the residual block to generate the residual block using Residual Differential Pulse Codec Modulation (RDPCM). In some examples, residual generation unit 204 may be formed using one or more subtractor circuits performing binary subtraction.

[0100] In the example where mode selection unit 202 divides a CU into PUs, each PU can be associated with a luma prediction unit and a corresponding chroma prediction unit. Video encoder 200 and video decoder 300 can support PUs of various sizes. As mentioned above, the size of a CU can refer to the size of its luma codec block, and the size of a PU can refer to the size of the luma prediction unit of the PU. Assuming a specific CU size is 2N×2N, video encoder 200 can support PU sizes of 2N×2N or N×N for intra-frame prediction, and symmetrical PU sizes of 2N×2N, 2N×N, N×2N, N×N, or similar for inter-frame prediction. Video encoder 200 and video decoder 300 can also support asymmetric partitioning of PU sizes of 2N×nU, 2N×nD, nL×2N, and nR×2N for inter-frame prediction.

[0101] In the example where mode selection unit 202 does not further divide the CU into PUs, each CU can be associated with a luma codec block and a corresponding chroma codec block. Similarly, the size of the CU can refer to the size of the luma codec block of the CU. The video encoder 200 and video decoder 300 can support CU sizes of 2N×2N, 2N×N, or N×2N.

[0102] For other video codec techniques, such as intra-block copy mode codec, affine mode codec, and linear model (LM) mode codec, as some examples, mode selection unit 202 generates a prediction block for the current block being encoded via a corresponding unit associated with the codec technique. In some examples, such as palette mode codec, mode selection unit 202 may not generate a prediction block, but instead generate syntax elements indicating how the block should be reconstructed based on the selected palette. In such a mode, mode selection unit 202 can provide these syntax elements to entropy coding unit 220 for encoding.

[0103] As described above, the residual generation unit 204 receives video data of the current block and the corresponding prediction block. Then, the residual generation unit 204 generates a residual block for the current block. To generate the residual block, the residual generation unit 204 calculates the sample-by-sample difference between the prediction block and the current block.

[0104] Transform processing unit 206 applies one or more transformations to the residual block to generate a block of transform coefficients (referred to herein as a "transform coefficient block"). Transform processing unit 206 can apply various transformations to the residual block to form the transform coefficient block. For example, transform processing unit 206 can apply discrete cosine transform (DCT), direction transformation, Karhunen-Loeve transform (KLT), or conceptually similar transformations to the residual block. In some examples, transform processing unit 206 can perform multiple transformations on the residual block, such as primary and secondary transformations, such as rotation transformations. In some examples, transform processing unit 206 does not apply any transformations to the residual block.

[0105] Quantization unit 208 can quantize the transform coefficients in a transform coefficient block to produce a quantized transform coefficient block. Quantization unit 208 can quantize the transform coefficients of the transform coefficient block based on the quantization parameter (QP) value associated with the current block. Video encoder 200 (e.g., via mode selection unit 202) can adjust the degree of quantization applied to the transform coefficient block associated with the current block by adjusting the QP value associated with the CU. Quantization may introduce information loss, and therefore, the quantized transform coefficients may have lower precision than the original transform coefficients generated by transform processing unit 206.

[0106] The inverse quantization unit 210 and the inverse transform processing unit 212 can apply inverse quantization and inverse transform to the quantized transform coefficient block, respectively, to reconstruct the residual block from the transform coefficient block. The reconstruction unit 214 can generate a reconstructed block corresponding to the current block based on the reconstructed residual block and the prediction block generated by the mode selection unit 202 (although it may have some degree of distortion). For example, the reconstruction unit 214 can add samples of the reconstructed residual block to the corresponding samples of the prediction block generated by the mode selection unit 202 to generate the reconstructed block.

[0107] Filter unit 216 can perform one or more filtering operations on the reconstructed block. For example, filter unit 216 can perform a deblocking operation to reduce block artifacts along the edges of the CU. In some examples, the operation of filter unit 216 can be skipped. In some examples, filter unit 216 can be configured to perform the deblocking filter parameter signaling techniques described above in this disclosure. In other examples, other structural units of the video encoder 200 can be configured to perform deblocking filter parameter signaling techniques.

[0108] For example, as described above, filter unit 216 can be configured to determine the values ​​of deblocking filter parameters based on a set of values. In one example, the deblocking filter parameters include one or more of a deblocking filter threshold offset or a limiting value offset. Filter unit 216 can be configured to apply a deblocking filter to video data based on the values ​​of the deblocking filter parameters. Filter unit 216 or another structural unit of video encoder 200 can be configured to signal one or more syntax elements in the parameter set that indicate the set of values ​​related to the deblocking filter parameters.

[0109] The video encoder 200 stores reconstructed blocks in the DPB 218. For example, in an example where the filter unit 216 is not operating, the reconstruction unit 214 can store the reconstructed blocks in the DPB 218. In an example where the filter unit 216 is operating, the filter unit 216 can store the filtered reconstructed blocks in the DPB 218. The motion estimation unit 222 and the motion compensation unit 224 can retrieve a reference image formed by the reconstructed (and potentially filtered) blocks from the DPB 218 to perform inter-frame prediction of blocks in subsequently encoded images. Furthermore, the intra-frame prediction unit 226 can use the reconstructed blocks in the DPB 218 of the current image to perform intra-frame prediction of other blocks in the current image.

[0110] Typically, entropy coding unit 220 can entropy-encode syntax elements received from other functional components of video encoder 200. For example, entropy coding unit 220 can entropy-encode quantized transform coefficient blocks from quantization unit 208. As another example, entropy coding unit 220 can entropy-encode predictive syntax elements (e.g., motion information for inter-frame prediction or intra-frame mode information for intra-frame prediction) from mode selection unit 202. Entropy coding unit 220 can perform one or more entropy coding operations on syntax elements, another example of video data, to generate entropy-encoded data. For example, entropy coding unit 220 can perform context-adaptive variable-length codec (CAVLC), CABAC, variable-to-variable (V2V) length codec, syntax-based context-adaptive binary arithmetic codec (SBAC), probabilistic interval partitioned entropy (PIPE) codec, exponential Golomb codec, or another type of entropy coding operation on the data. In some examples, entropy coding unit 220 can operate in bypass mode, in which syntax elements are not entropy-encoded.

[0111] The video encoder 200 can output a bitstream containing the entropy-encoded syntax elements required to reconstruct strips or images. Specifically, the entropy coding unit 220 can output a bitstream.

[0112] The above operations are described at the block level. This description should be understood as operations applied to luma codec blocks and / or chroma codec blocks. As mentioned above, in some examples, the luma codec block and chroma codec block are the luma and chroma components of the CU. In some examples, the luma codec block and chroma codec block are the luma and chroma components of the PU.

[0113] In some examples, for the chroma codec block, it is not necessary to repeat the operations performed for the luma codec block. As an example, the operations for identifying the motion vector (MV) and reference image for the luma codec block do not need to be repeated for identifying the MV and reference image for the chroma block. Instead, the MV for the luma codec block can be scaled to determine the MV for the chroma block, and the reference image can be the same. As another example, the intra-frame prediction process can be the same for both the luma and chroma codec blocks.

[0114] Video encoder 200 represents an example of a device configured to encode video data, which includes a memory configured to store the video data, and one or more processing units implemented in circuitry and configured to encode a set of values ​​for deblocking filter parameters in a parameter set and to signal the parameter set in the encoded video bitstream.

[0115] Figure 4 This is a block diagram illustrating an exemplary video decoder 300 capable of performing the techniques of this disclosure. Provided Figure 4 This disclosure is for illustrative purposes and not for limiting the techniques extensively illustrated and described herein. For illustrative purposes, this disclosure describes a video decoder 300 based on VVC (ITU-TH.266, under development) and HEVC (ITU-TH.265) technologies. However, the techniques of this disclosure can be implemented by video codec devices configured to other video codec standards.

[0116] exist Figure 4In the example, the video decoder 300 includes an encoded picture buffer (CPB) memory 320, an entropy decoding unit 302, a prediction processing unit 304, an inverse quantization unit 306, an inverse transform processing unit 308, a reconstruction unit 310, a filter unit 312, and a decoded picture buffer (DPB) 314. Any or all of the CPB memory 320, entropy decoding unit 302, prediction processing unit 304, inverse quantization unit 306, inverse transform processing unit 308, reconstruction unit 310, filter unit 312, and DPB 314 can be implemented in one or more processors or processing circuits. For example, the units of the video decoder 300 can be implemented as part of hardware circuitry or as part of a processor, ASIC, or FPGA, or as one or more circuit or logic elements. Furthermore, the video decoder 300 may include additional or alternative processors or processing circuitry to perform these and other functions.

[0117] The prediction processing unit 304 includes a motion compensation unit 316 and an intra-prediction unit 318. The prediction processing unit 304 may include additional units to perform predictions according to other prediction modes. As an example, the prediction processing unit 304 may include a palette unit, an intra-block copying unit (which may form part of the motion compensation unit 316), an affine unit, a linear model (LM) unit, etc. In other examples, the video decoder 300 may include more, fewer, or different functional components.

[0118] CPB memory 320 can store video data to be decoded by components of video decoder 300, such as encoded video bitstreams. For example, it can be stored from computer-readable medium 110 ( Figure 1 The video data stored in the CPB memory 320 is obtained. The CPB memory 320 may include a CPB that stores encoded video data (e.g., syntax elements) from the encoded video bitstream. Furthermore, the CPB memory 320 may store video data other than the syntax elements of the encoded / decoded pictures, such as temporary data representing the output from various units of the video decoder 300. The DPB 314 typically stores decoded pictures that the video decoder 300 may output and / or use as reference video data when decoding subsequent data or pictures from the encoded video bitstream. The CPB memory 320 and DPB 314 may be formed of any of a variety of storage devices, such as DRAM, including SDRAM, MRAM, RRAM, or other types of storage devices. The CPB memory 320 and DPB 314 may be provided by the same memory device or separate memory devices. In various examples, the CPB memory 320 may be placed on-chip with other components of the video decoder 300, or off-chip relative to those components.

[0119] Alternatively or alternatively, in some examples, the video decoder 300 can be derived from the memory 120 ( Figure 1 Retrieving encoded and decoded video data. That is, memory 120 can store data using CPB memory 320 as discussed above. Similarly, when some or all of the functions of video decoder 300 are implemented in software executed by the processing circuitry of video decoder 300, memory 120 can store instructions to be executed by video decoder 300.

[0120] Figure 4 The various units shown are illustrated to aid in understanding the operations performed by the video decoder 300. These units can be implemented as fixed-function circuits, programmable circuits, or a combination thereof. Similar to... Figure 3 Fixed-function circuits are circuits that provide a specific function and are pre-defined in terms of the operations they can perform. Programmable circuits are circuits that can be programmed to perform various tasks and provide flexible functionality in the operations they can perform. For example, a programmable circuit can run software or firmware, causing it to operate in a manner defined by the instructions of the software or firmware. Fixed-function circuits can run software instructions (e.g., to receive or output parameters), but the type of operation performed by a fixed-function circuit is usually immutable. In some examples, one or more units may be different circuit blocks (fixed-function or programmable), and in some examples, one or more units may be integrated circuits.

[0121] The video decoder 300 may include an ALU, an EFU, digital circuitry, analog circuitry, and / or a programmable core formed by programmable circuitry. In an example where the operation of the video decoder 300 is performed by software running on the programmable circuitry, on-chip or off-chip memory may store instructions (e.g., object code) of the software received and executed by the video decoder 300.

[0122] Entropy decoding unit 302 can receive encoded video data from CPB and perform entropy decoding on the video data to reconstruct syntax elements. Prediction processing unit 304, inverse quantization unit 306, inverse transform processing unit 308, reconstruction unit 310, and filter unit 312 can generate decoded video data based on syntax elements extracted from the bitstream.

[0123] Typically, the video decoder 300 reconstructs the image on a block-by-block basis. The video decoder 300 can perform the reconstruction operation separately for each block (where the block currently being reconstructed, i.e., the decoded block, can be referred to as the "current block").

[0124] Entropy decoding unit 302 can entropy decode the syntax elements of the quantized transform coefficients defining the quantized transform coefficient block, as well as transform information (such as quantization parameters (QP) and / or (multiple) transform mode indications). Inverse quantization unit 306 can use the QP associated with the quantized transform coefficient block to determine the degree of quantization, and similarly, determine the degree of inverse quantization to be applied by inverse quantization unit 306. Inverse quantization unit 306 can, for example, perform a bit-by-bit left shift operation to inverse quantize the quantized transform coefficients. Inverse quantization unit 306 can thus form a transform coefficient block including the transform coefficients.

[0125] After the inverse quantization unit 306 forms the transform coefficient block, the inverse transform processing unit 308 can apply one or more inverse transforms to the transform coefficient block to generate a residual block associated with the current block. For example, the inverse transform processing unit 308 can apply the inverse DCT, inverse integer transform, inverse Karhunen-Loeve transform (KLT), inverse rotation transform, inverse direction transform, or another inverse transform to the transform coefficient block.

[0126] Furthermore, the prediction processing unit 304 generates a prediction block based on the prediction information syntax elements entropy-decoded by the entropy decoding unit 302. For example, if the prediction information syntax elements indicate that the current block is inter-frame predicted, the motion compensation unit 316 can generate the prediction block. In this case, the prediction information syntax elements may indicate a reference image in the DPB 314 from which the reference block is retrieved, and a motion vector identifying the position of the reference block in the reference image relative to the current block in the current image. The motion compensation unit 316 can typically be configured in conjunction with the motion compensation unit 224 ( Figure 3 The method described is essentially the same as the method used to perform the inter-frame prediction process.

[0127] As another example, if the prediction information syntax element indicates that the current block is intra-predictable, then intra-prediction unit 318 can generate a prediction block according to the intra-prediction mode indicated by the prediction information syntax element. Furthermore, intra-prediction unit 318 can typically be configured with the same syntax as intra-prediction unit 226. Figure 3 The intra-prediction process is performed in a manner substantially similar to that described above. The intra-prediction unit 318 can retrieve data of neighboring samples from the DPB 314 for the current block.

[0128] Reconstruction unit 310 can use prediction blocks and residual blocks to reconstruct the current block. For example, reconstruction unit 310 can add samples from the residual block to the corresponding samples from the prediction block to reconstruct the current block.

[0129] Filter unit 312 can perform one or more filtering operations on the reconstructed block. For example, filter unit 312 can perform a deblocking operation to reduce block artifacts along the edges of the reconstructed block. The operation of filter unit 312 is not necessarily performed in all examples. Filter unit 312 can be configured to perform the deblocking filter parameter decoding techniques of this disclosure. In other examples, other structural units of video decoder 300 can be configured to decode and parse deblocking filter parameters. In one example of this disclosure, filter unit 312 can be configured to: decode a set of values ​​for deblocking filter parameters in a parameter set, determine the value of the deblocking filter parameter based on the set of values, and apply a deblocking filter to video data using the value of the deblocking filter parameter. In one example, the deblocking filter parameters include one or more of a deblocking filter threshold offset or a limiting value offset.

[0130] The video decoder 300 can store the reconstructed blocks in the DPB 314. For example, in an example where the filter unit 312 is not operated, the reconstruction unit 310 can store the reconstructed blocks in the DPB 314. In an example where the filter unit 312 is operated, the filter unit 312 can store the filtered reconstructed blocks in the DPB 314. As described above, the DPB 314 can provide reference information to the prediction processing unit 304, such as samples of the current image for intra-frame prediction and previous decoded images for subsequent motion compensation. Furthermore, the video decoder 300 can output the decoded image (e.g., decoded video) from the DPB 314 for subsequent presentation in applications such as... Figure 1 Display devices such as 118.

[0131] In this manner, video decoder 300 represents an example of a video decoding device, which includes a memory configured to store video data, and one or more processing units implemented in circuitry and configured to: decode a set of values ​​in a parameter set related to deblocking filter parameters, determine the values ​​of the deblocking filter parameters based on the set of values, and apply a deblocking filter to the video data based on the values ​​of the deblocking filter parameters.

[0132] Figure 5 This is a flowchart illustrating an exemplary method for encoding a current block according to the technology of this disclosure. The current block may include the current CU. Although regarding video encoder 200 ( Figure 1 and Figure 3 This description is provided, but it should be understood that other devices can be configured to perform similar actions. Figure 5 The method.

[0133] In this example, the video encoder 200 initially predicts the current block (350). For example, the video encoder 200 may form a predicted block for the current block. The video encoder 200 may then compute a residual block for the current block (352). To compute the residual block, the video encoder 200 may compute the difference between the original, unencoded block and the predicted block for the current block. The video encoder 200 may then transform and quantize the transform coefficients of the residual block (354). Next, the video encoder 200 may scan the quantized transform coefficients of the residual block (356). During or after the scan, the video encoder 200 may entropy encode the transform coefficients (358). For example, the video encoder 200 may encode the transform coefficients using CAVLC or CABAC. The video encoder 200 may then output the entropy-encoded data of the block (360).

[0134] Figure 6 This is a flowchart illustrating an example method for decoding a current block of video data according to the technology of this disclosure. The current block may include the current CU. Although regarding the video decoder 300 ( Figure 1 and Figure 4 This description is provided, but it should be understood that other devices can be configured to perform similar actions. Figure 6 The method.

[0135] The video decoder 300 can receive entropy-encoded data of the current block, such as entropy-encoded prediction information of the transform coefficients of the residual block corresponding to the current block and entropy-encoded data (370). The video decoder 300 can decode the entropy-encoded data to determine the prediction information for the current block and reproduce the transform coefficients of the residual block (372). The video decoder 300 can predict the current block (374), for example, using an intra-frame or inter-frame prediction mode indicated by the prediction information of the current block to compute a prediction block for the current block. The video decoder 300 can then inversely scan the reproduced transform coefficients (376) to create a block of quantized transform coefficients. The video decoder 300 can then inversely quantize the transform coefficients and apply the inverse transform to the transform coefficients to produce a residual block (378). The video decoder 300 can finally decode the current block by combining the prediction block and the residual block (380).

[0136] Figure 7 This is a flowchart illustrating another exemplary method for decoding the current block according to the technology of this disclosure. Figure 7 The technology can be implemented by one or more structural components of the video decoder 300, including filter unit 312.

[0137] In one example of this disclosure, the video decoder 300 may be configured to decode (400) a set of values ​​in a parameter set that are associated with the deblocking filter parameters. This parameter set may be one or more of a sequence parameter set, a video parameter set, a picture parameter set, or an adaptive parameter set.

[0138] The video decoder 300 can also be configured to: determine the values ​​of deblocking filter parameters based on the set of values ​​(410), and apply the deblocking filter to the video data based on the values ​​of the deblocking filter parameters (420). In one example, the deblocking filter parameters include one or more of a deblocking filter threshold offset or a limiting value offset. In one example, the video decoder 300 is configured to: determine a deblocking filter threshold (β) based on the deblocking filter threshold offset (betaOffset), and apply the deblocking filter to the video data using the deblocking filter threshold (β). In another example, the video decoder 300 is configured to: determine a limiting value (TcOffset) based on the limiting value offset (TcOffset). c ), and the use of the amplitude limit (T) c Apply the deblocking filter to the video data.

[0139] In another example of this disclosure, the video decoder 300 may be configured to decode a syntax element that indicates the number of values ​​in a set of values ​​for deblocking filter parameters in a parameter set.

[0140] In another example of this disclosure, in order to determine the values ​​of the deblocking filter parameters based on the set of values, the video decoder 300 may be configured to determine the values ​​of the deblocking filter parameters based on the set of values, wherein the codec information includes one or more of a time layer index, a codec type, or one or more quantization parameters.

[0141] In another example of this disclosure, in order to determine the value of the deblocking filter parameter based on the set of values, the video decoder 300 may be configured to: decode an index from the set of values ​​indicating the value of the deblocking filter parameter, and determine the deblocking filter parameter based on the index.

[0142] In another example of this disclosure, in order to determine the value of the deblocking filter parameter based on the set of values, the video decoder 300 may be configured to: determine an initial value for the deblocking filter parameter based on the set of values, decode the offset, and determine the deblocking filter parameter by adding the offset to the initial value of the deblocking filter parameter.

[0143] Other illustrative examples of this disclosure are described below.

[0144] Aspect 1 - A method for decoding video data, the method comprising: decoding a set of values ​​for deblocking filter parameters in a parameter set; determining values ​​for the deblocking filter parameters based on the set of values; and applying a deblocking filter to the video data using the values ​​of the deblocking filter parameters.

[0145] Aspect 2 - According to the method of Aspect 1, wherein the deblocking filter parameters include one or more of betaOffset or TcOffset.

[0146] Aspect 3 - According to the method of Aspect 1, wherein the parameter set is one or more of a sequence parameter set, a video parameter set, an image parameter set, or an adaptive parameter set.

[0147] Aspect 4 - According to the method of aspect 1, it further includes: decoding the syntax element indicating the number of values ​​in the value set for the deblocking filter parameters in the parameter set.

[0148] Aspect 5 - According to the method of Aspect 1, wherein determining the value of the deblocking filter parameter based on the value set includes: determining the value of the deblocking filter parameter based on the value set according to encoding and decoding information, wherein the encoding and decoding information includes one or more of a time layer index, encoding and decoding type, or one or more quantization parameters.

[0149] Aspect 6 - The method according to aspect 1, wherein determining the value of the deblocking filter parameter based on the set of values ​​includes: decoding an index from the set of values ​​indicating the value of the deblocking filter parameter; and determining the deblocking filter parameter based on the index.

[0150] Aspect 7 - According to the method of Aspect 1, wherein determining the value of the deblocking filter parameter based on the set of values ​​includes: determining an initial value of the deblocking filter parameter based on the set of values; decoding the offset; and determining the deblocking filter parameter by adding the offset to the initial value of the deblocking filter parameter.

[0151] Aspect 8 - An apparatus for encoding and decoding video data, the apparatus comprising one or more components for performing the methods of any one of aspects 1-7.

[0152] Aspect 9 - The device according to aspect 8, wherein the one or more components include one or more processors implemented in a circuit.

[0153] Aspect 10 - The device according to any one of aspects 8 and 9, the device further includes a memory for storing video data.

[0154] Aspect 11 - The device according to any one of aspects 8-10, the device further includes a display configured to display decoded video data.

[0155] Aspect 12 - An apparatus according to any one of aspects 8-11, wherein the apparatus includes one or more of a camera, a computer, a mobile device, a broadcast receiver device, or a set-top box.

[0156] Aspect 13 - A device according to any one of aspects 8-12, wherein the device includes a video decoder.

[0157] Aspect 14 - A device according to any one of aspects 8-13, wherein the device includes a video encoder.

[0158] Aspect 15 - A computer-readable storage medium having instructions stored thereon, which, when executed, cause one or more processors to perform the method of any one of aspects 1-7.

[0159] It is understood that, depending on the example, certain actions or events of any of the techniques described herein may be performed in a different order, and may be added, combined, or omitted together (e.g., not all described actions or events are necessary for the practice of the technique). Furthermore, in some examples, actions or events may be performed concurrently, for example, through multithreading, interrupt handling, or multiple processors, rather than sequentially.

[0160] In one or more examples, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, these functions may be stored as one or more instructions or code on or through a computer-readable medium and executed by a hardware-based processing unit. A computer-readable medium may include a computer-readable storage medium corresponding to a tangible medium such as a data storage medium, or a communication medium that includes, for example, any medium facilitating the transfer of a computer program from one place to another according to a communication protocol. In this way, a computer-readable medium may generally correspond to (1) a non-transitory tangible computer-readable storage medium, or (2) a communication medium such as a signal or carrier wave. A data storage medium may be any available medium accessible by one or more computers or one or more processors to retrieve instructions, code, and / or data structures for implementing the techniques described in this disclosure. Computer program products may include computer-readable media.

[0161] By way of example and not limitation, such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, flash memory, or any other medium that can be used to store required program code in the form of instructions or data structures and that can be accessed by a computer. Furthermore, any connection is properly referred to as a computer-readable medium. For example, if instructions are transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies (such as infrared, radio, and microwave), then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies (such as infrared, radio, and microwave) are included in the definition of medium. However, it should be understood that computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other transient media, but rather refer to non-transient tangible storage media. As used herein, disks and optical discs include compact optical discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, where disks typically reproduce data magnetically, while optical discs reproduce data optically using lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0162] Instructions can be executed by one or more processors, such as one or more DSPs, general-purpose microprocessors, ASICs, FPGAs, or other equivalent integrated or discrete logic circuits. Therefore, the terms "processor" and "processing circuit" as used herein can refer to any of the foregoing structures or any other structure suitable for implementing the techniques described herein. Additionally, in some aspects, the functionality described herein can be provided in dedicated hardware and / or software modules configured for encoding and decoding, or incorporated into combined codecs. Similarly, these techniques can be fully implemented in one or more circuit or logic elements.

[0163] The techniques disclosed herein can be implemented in a variety of devices or apparatuses, including wireless mobile phones, integrated circuits (ICs), or IC sets (e.g., chipsets). Various components, modules, or units are described in this disclosure to highlight functional aspects of a device configured to perform the disclosed techniques, but implementation by different hardware units is not necessarily required. Rather, as described above, various units can be combined in a codec hardware unit, or provided by a collection of interoperable hardware units including one or more processors as described above, combined with suitable software and / or firmware.

[0164] Various examples have been described. These and other examples are within the scope of the appended claims.

Claims

1. A method for decoding video data, the method comprising: Decode the set of values ​​in the first parameter set that are related to the deblocking filter parameters; Decode the temporal indexes associated with images or sub-images in the video data; For the image or sub-image, a specific value of the deblocking filter parameter is determined based on the decoded temporal layer index and the value set. as well as The deblocking filter is applied to the video data based on the values ​​of the deblocking filter parameters.

2. The method according to claim 1, wherein, The deblocking filter parameters include one or more of the deblocking filter threshold offset or the limiting value offset.

3. The method according to claim 2, further comprising: The deblocking filter threshold β is determined based on the deblocking filter threshold offset betaOffset; as well as The deblocking filter is applied to the video data using the deblocking filter threshold β.

4. The method according to claim 2, further comprising: The limiting value T is determined based on the limiting value offset TcOffset. c ; as well as Using the aforementioned amplitude limit T c The deblocking filter is applied to the video data.

5. The method according to claim 1, wherein, The first parameter set is one or more of a sequence parameter set, a video parameter set, an image parameter set, or an adaptive parameter set, and the method further includes: The first parameter set is received in the encoded video bitstream.

6. The method according to claim 1, further comprising: The syntax element indicating the number of values ​​in the set of values ​​used for the deblocking filter parameters in the first parameter set is decoded.

7. The method of claim 1, wherein the time layer index is in a second parameter set or header of the encoded video bitstream, and wherein the second parameter set or header is at a lower level than the first parameter set.

8. The method according to claim 1, wherein, A portion of the video data associated with the time-layer index includes either images or strips.

9. The method according to claim 1, wherein, Determining the values ​​of the deblocking filter parameters based on the set of values ​​includes: The initial values ​​of the deblocking filter parameters are determined based on the set of values; Decode the offset; and The deblocking filter parameters are determined by adding the offset to the initial value of the deblocking filter parameters.

10. The method according to claim 1, further comprising: Displays an image that includes deblocked and filtered video data.

11. An apparatus configured to decode video data, the apparatus comprising: The memory is configured to store video data; as well as One or more processors, implemented in the circuit and communicating with the memory, are configured to cause the device to: Decode the set of values ​​in the first parameter set that are related to the deblocking filter parameters; Decode the temporal indexes associated with images or sub-images in the video data; For the image or sub-image, a specific value of the deblocking filter parameter is determined based on the decoded temporal layer index and the value set. as well as The deblocking filter is applied to the video data based on the values ​​of the deblocking filter parameters.

12. The apparatus according to claim 11, wherein, The deblocking filter parameters include one or more of the deblocking filter threshold offset or the limiting value offset.

13. The apparatus according to claim 12, wherein, The one or more processors are further configured to cause the device to: The deblocking filter threshold β is determined based on the deblocking filter threshold offset betaOffset; and The deblocking filter is applied to the video data using the deblocking filter threshold β.

14. The apparatus according to claim 12, wherein, The one or more processors are further configured to cause the device to: The limiting value T is determined based on the limiting value offset TcOffset. c ;as well as Using the aforementioned amplitude limit T c The deblocking filter is applied to the video data.

15. The apparatus according to claim 11, wherein, The first parameter set is one or more of a sequence parameter set, a video parameter set, an image parameter set, or an adaptive parameter set, wherein the one or more processors are configured to cause the device to: The first parameter set is received in the encoded video bitstream.

16. The apparatus according to claim 11, wherein, The one or more processors are further configured to cause the device to: The syntax element indicating the number of values ​​in the set of values ​​used for the deblocking filter parameters in the first parameter set is decoded.

17. The apparatus of claim 11, wherein the time layer index is in a second parameter set or header of the encoded video bitstream, and wherein the second parameter set or header is at a lower level than the first parameter set.

18. The apparatus according to claim 11, wherein, A portion of the video data associated with the time-layer index includes either images or strips.

19. The apparatus according to claim 11, wherein, In order to determine the values ​​of the deblocking filter parameters based on the set of values, the one or more processors are further configured to cause the device to: The initial values ​​of the deblocking filter parameters are determined based on the set of values; Decode the offset; and The deblocking filter parameters are determined by adding the offset to the initial value of the deblocking filter parameters.

20. The apparatus of claim 11, further comprising: The display is configured to show an image that includes deblocked video data.

21. An apparatus configured to decode video data, the apparatus comprising: A component used to decode the set of values ​​in the first parameter set that are related to the deblocking filter parameters; A component used to decode temporal layer indexes associated with images or sub-images of video data; A component for determining, for the image or sub-image, a specific value of the deblocking filter parameter based on the set of values, according to the decoded temporal layer index; as well as A component for applying a deblocking filter to the video data based on the values ​​of the deblocking filter parameters.

22. The apparatus of claim 21, further comprising components for performing the steps of the method according to any one of claims 2-10.

23. A non-transitory computer-readable storage medium storing instructions, which, when executed, cause one or more processors of a device configured to decode video data: Decode the set of values ​​in the first parameter set that are related to the deblocking filter parameters; Decode the temporal indexes associated with images or sub-images in the video data; For the image or sub-image, a specific value of the deblocking filter parameter is determined based on the decoded temporal layer index and the value set. as well as The deblocking filter is applied to the video data based on the values ​​of the deblocking filter parameters.

24. The non-transitory computer-readable storage medium of claim 23, wherein the instructions, when executed, also cause one or more processors of the device to perform the method of any one of claims 2-10.

25. A computer program product comprising instructions that, when executed, cause one or more processors of a device configured to decode video data to perform the method according to any one of claims 1-10.

Images