KR20230159427A - Picture Orientation and Quality Metrics Supplementary Enhancement Information Messages for Video Coding - Google Patents

Abstract

The video encoder and video decoder are composed of Supplemental Enhancement Information (SEI) messages. The SEI message may include an image orientation transformation type syntax element that indicates how the image may be rotated and/or mirrored. SEI messages may also include quality metrics.

Description

Picture Orientation and Quality Metrics Supplementary Enhancement Information Messages for Video Coding

This application is related to U.S. Patent Application No. 17/653,945, filed March 8, 2022, and U.S. Provisional Application No. 63/170,267, filed April 2, 2021, and U.S. Provisional Application No. 63/170,267, filed June 24, 2021. Claims the benefit of U.S. Provisional Application No. 63/214,378, the entire contents of each of which are incorporated herein by reference. U.S. Patent Application No. 17/653,945, filed March 8, 2022, U.S. Provisional Application No. 63/170,267, filed April 2, 2021, and U.S. Provisional Application No. 63/214,378, filed June 24, 2021 Claim your interests.

Technology field

This disclosure relates to video encoding and video decoding.

Digital video capabilities include digital televisions, digital direct broadcast systems, wireless broadcast systems, personal digital assistants (PDAs), laptop or desktop computers, tablet computers, e-readers, digital cameras, and digital recording devices. can be included in a wide range of devices, including digital media players, video gaming devices, video game consoles, cellular or satellite wireless phones, so-called “smart phones,” teleconferencing devices, video streaming devices, etc. there is. Digital video devices support MPEG-2, MPEG-4, ITU-T H.263, ITU-T H.264/MPEG-4, Part 10, Advanced Video Coding (AVC), and ITU-T H.265/High Efficiency Video. Video coding techniques such as those described in (HEVC), the standards defined by ITU-T H.266/VVC (Versatile Video Coding), and extensions of those standards, as well as the Alliance for Open Media Implements proprietary video codecs/formats such as AV1 (AOMedia Video 1) developed by Media. Video devices may transmit, receive, encode, decode, and/or store digital video information more efficiently by implementing such video coding techniques.

Video coding 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, a video slice (e.g., a video picture or part of a video picture) may be partitioned into video blocks, which are divided into coding tree units (CTUs), coding units (CUs). and/or may also be referred to as coding nodes. Video blocks in an intra-coded (I) slice of a picture are encoded using spatial prediction with respect to reference samples in neighboring blocks of the same picture. Video blocks within an inter-coded (P or B) slice of a picture may use spatial prediction relative to reference samples in neighboring blocks within the same picture, or temporal prediction relative to reference samples in other reference pictures. . Pictures may be referred to as frames, and reference pictures may be referred to as reference frames.

outline

In general, this disclosure describes techniques for coding video data. In particular, the present disclosure provides messages (e.g., Supplemental Enhancement Information (SEI) messages and/or other packetized structures) that include metadata to aid in processing (e.g., decoding, displaying, etc.) video data. Describes techniques for encoding and decoding. Messages of the present disclosure may include syntax elements indicating the orientation of the image and/or the transformation to apply to the decoded image, which may be used to rotate and/or mirror the decoded image to a desired orientation. A syntax element may represent a transformation for a full image or component images (e.g., left and right view stereoscopic images) for display. In another example, the message may include syntax elements representing picture quality metrics. Image quality metrics may indicate the encoding quality of the image, such as quality-based viewport switching and quality-based metric measurements.

A video decoder or other device may decode the message and process an image of the video data according to the message. The picture orientation message may be used to provide the video decoder with instructions for recommended orientation transformations to apply to the decoded picture. In this way, the display of the decoded image may be viewed in a more appropriate orientation. A video decoder may use the quality metrics in post-processing of decoded pictures and/or may use the quality metrics to select higher quality pictures to use for inter prediction.

In one example, the present disclosure describes a method of processing video data, the method comprising receiving a picture, and coding a picture orientation message including a transform type syntax element, wherein the transform type syntax element is a plurality of Among the transformations, indicates the transformation to be applied to the image.

In another example, the disclosure describes an apparatus configured to process video data, the apparatus comprising a memory configured to store an image, and one or more processors implemented in circuitry and in communication with the memory, the one or more processors configured to process video data. and to code an image orientation message comprising a transformation type syntax element, wherein the transformation type syntax element indicates a transformation to be applied to the image, among a plurality of transformations.

In another example, the present disclosure describes an apparatus configured to process video data, the apparatus comprising means for receiving a picture, and means for coding a picture orientation message comprising a transform type syntax element, wherein the transform type syntax element includes: The element represents the transformation to be applied to the image among a plurality of transformations.

In another example, the present disclosure describes a non-transitory computer-readable storage medium storing instructions that, when executed, cause one or more processors of a device configured to process video data to receive an image, and execute a transform type syntax element. and code a picture orientation message comprising, wherein a transformation type syntax element indicates a transformation to be applied to the picture, among a plurality of transformations.

In another example, the present disclosure describes a method of processing video data, the method comprising receiving a picture, and coding a quality metrics message including a quality metrics syntax element, wherein the quality metrics syntax element represents the value of the quality metric related to the image.

In another example, the disclosure describes an apparatus configured to process video data, the apparatus comprising a memory configured to store an image, and one or more processors implemented in circuitry and in communication with the memory, the one or more processors configured to process video data. and configured to code a quality metrics message comprising a quality metrics syntax element, wherein the quality metrics syntax element represents a value of a quality metric associated with the image.

In another example, the present disclosure describes an apparatus configured to process video data, the apparatus comprising means for receiving an image, and means for coding a quality metrics message including a quality metrics syntax element, wherein the quality metrics syntax element includes: The element represents the value of a quality metric related to the image.

In another example, the present disclosure describes a non-transitory computer-readable storage medium storing instructions that, when executed, cause one or more processors of a device configured to process video data to receive an image and generate quality metric syntax elements. Coding a quality metrics message comprising, wherein the quality metrics syntax element represents the value of the quality metric associated with the image.

Details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects and advantages will become apparent from the detailed description, drawings, and claims.

1 is a block diagram illustrating an example video encoding and decoding system that may perform the techniques of this disclosure.
2 is a conceptual diagram illustrating an example rotation of an image.
3 is a conceptual diagram illustrating example transformation types.
4 is a flow chart illustrating an example process for coding an image orientation supplemental enhancement information message.
FIG. 5 is a flow chart illustrating an example process for coding a quality metrics replenishment enhancement information message.
6 is a block diagram illustrating an example video encoder that may perform the techniques of this disclosure.
7 is a block diagram illustrating an example video decoder that may perform the techniques of this disclosure.
8 is a flowchart illustrating an example method for encoding a current block according to the techniques of this disclosure.
9 is a flow chart illustrating an example method for decoding a current block according to the techniques of this disclosure.

details

The present disclosure encodes messages (e.g., Supplemental Enhancement Information (SEI) messages and/or other packetized structures) that include metadata to aid in processing (e.g., decoding, displaying, etc.) video data. and techniques for decoding are described. Messages of the present disclosure may include syntax elements indicating the orientation of the image and/or the transformation to apply to the decoded image, which may be used to rotate and/or mirror the decoded image to a desired orientation. A syntax element may represent a transformation for a full image or component images (e.g., left and right view stereoscopic images) for display. In another example, the message may include syntax elements representing picture quality metrics. Image quality metrics may indicate the encoding quality of the image, such as quality-based viewport switching and quality-based metric measurements.

A video decoder or other device may decode the message and process an image of the video data according to the message. The picture orientation message may be used to provide the video decoder with instructions for recommended orientation transformations to apply to the decoded picture. In this way, the display of the decoded image may be viewed in a more appropriate orientation. A video decoder may use the quality metrics in post-processing of decoded pictures and/or may use the quality metrics to select higher quality pictures to use for inter prediction.

1 is a block diagram illustrating an example video encoding and decoding system 100 that may perform the techniques of this disclosure. Techniques of this disclosure generally relate to coding (encoding and/or decoding) video data. Generally, video data includes arbitrary data for processing video. Accordingly, video data may include raw, unencoded video, encoded video, decoded (e.g., reconstructed) video, and video metadata, such as signaling data.

As shown in FIG. 1 , system 100 includes a source device 102 that provides encoded video data to be decoded and displayed by a destination device 116 in this example. In particular, source device 102 provides video data to destination device 116 via computer-readable medium 110. Source device 102 and destination device 116 include desktop computers, notebook (i.e., laptop) computers, mobile devices, tablet computers, set-top boxes, telephone handsets, such as smartphones, televisions, and cameras. may include any of a wide range of devices, including display devices, digital media players, video gaming consoles, video streaming devices, broadcast receiver devices, and the like. In some cases, source device 102 and destination device 116 may be equipped for wireless communication and thus may be referred to as wireless communication devices.

In the example of FIG. 1 , source device 102 includes video source 104, memory 106, video encoder 200, and output interface 108. Destination device 116 includes input interface 122, video decoder 300, memory 120, and display device 118. According to this disclosure, video encoder 200 of source device 102 and video decoder 300 of destination device 116 may be configured to apply techniques for SEI message coding. Accordingly, 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 device and destination device 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. Likewise, destination device 116 may be interfaced with an external display device, rather than including an integrated display device.

System 100 as shown in FIG. 1 is only one example. In general, any digital video encoding and/or decoding device may perform techniques for coding an SEI message. Source device 102 and destination device 116 are just examples of such coding devices where source device 102 generates coded video data for transmission to destination device 116. This disclosure refers to a “coding” device as a device that performs coding (encoding and/or decoding) of data. Accordingly, video encoder 200 and video decoder 300 represent examples of coding devices, particularly a video encoder and 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 may support one-way or two-way video transmission between source device 102 and destination device 116, for example, for video streaming, video playback, video broadcasting, or video telephony. .

In general, video source 104 represents a source of video data (i.e., raw, unencoded video data) and transmits a sequential series of pictures of the video data to video encoder 200, which encodes the data for the pictures. Video source 104 of source device 102 may be a video capture device, such as a video camera, a video archive containing previously captured raw video, and/or a video content provider. As a further alternative, video source 104 may include computer graphics-based data as the source video, or as a combination of live video, archived video, and computer-generated video. In each case, video encoder 200 encodes captured, pre-captured, or computer-generated video data. Video encoder 200 displays the images in the order in which they are received (sometimes referred to as "display order"). ") may be rearranged in the coding order for coding. Video encoder 200 may generate a bitstream containing encoded video data. Source device 102 may then, for example, The encoded video data may be output via output interface 108 onto computer-readable medium 110 for reception and/or retrieval by input interface 122 of destination device 116.

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

Computer-readable medium 110 may represent any type of medium or device capable of transferring encoded video data from source device 102 to destination device 116. In one example, computer-readable medium 110 may enable source device 102 to transmit encoded video data directly to destination device 116 in real time, e.g., via a radio frequency network or a computer-based network. It represents a communication medium to enable communication. Depending on a communication standard, such as a wireless communication protocol, output interface 108 may modulate a transmitted signal containing encoded video data and input interface 122 may demodulate a received transmitted signal. Communication media may include any wireless or wired communication medium, such as the radio frequency (RF) spectrum or one or more physical transmission lines. The communication medium may 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. Communication media may include routers, switches, base stations, or any other equipment that may be useful to facilitate communication from source device 102 to destination device 116.

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

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

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

Destination device 116 may access encoded video data from file server 114 via any standard data connection, including an Internet connection. This is suitable for accessing encoded video data stored on the file server 114, over a wireless channel (e.g., Wi-Fi connection), a wired connection (e.g., digital subscriber line (DSL), cable modem, etc.), or a combination of both. Input interface 122 may be configured to operate in accordance with any one or more of the various protocols discussed above for retrieving or receiving media data from file server 114, or other such protocols for retrieving media data. there is.

Output interface 108 and input interface 122 include wireless transmitters/receivers, modems, wired networking components (e.g., Ethernet cards), and wireless communications operating in accordance with any of the various IEEE 802.11 standards. It may also represent components, 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 support wireless components such as 4G, 4G-LTE (Long-Term Evolution), LTE Advanced, 5G, etc. Depending on cellular communication standards, it may be configured to transmit data, such as encoded video data. In some examples where output interface 108 includes a wireless transmitter, output interface 108 and input interface 122 may be configured to support other wireless signals, such as the IEEE 802.11 specification, IEEE 802.15 specification (e.g., ZigBee™), Bluetooth™ standard, etc. Depending on standards, it may be configured to transmit data such as encoded video data. In some examples, source device 102 and/or destination device 116 may include respective system-on-a-chip (SoC) devices. For example, source device 102 may include a SoC device to perform functionality due to video encoder 200 and/or output interface 108, and destination device 116 may include video decoder 300. and/or a SoC device to perform functionality due to input interface 122.

The technology of the present disclosure is applicable to over-the-air television broadcasting, cable television transmission, satellite television transmission, Internet streaming video transmission, such as dynamic adaptive streaming over HTTP (DASH), and encoding on data storage media. It may be applied to video coding to support any of a variety of multimedia applications, such as digital video, decoding of digital video stored on a data storage medium, or other applications.

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

Although not shown in FIG. 1, in some examples, video encoder 200 and video decoder 300 may be integrated with an audio encoder and/or an audio decoder, respectively, and include both audio and video in a common data stream. It may also include appropriate MUX-DEMUX units, or other hardware and/or software, to handle multiplexed streams.

Video encoder 200 and video decoder 300 each include 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 programming It may be implemented as any of possible gate arrays (FPGAs), discrete logic, software, hardware, firmware, or any combinations thereof. If the techniques are implemented in part in software, the device may store instructions for the software in a suitable non-transitory computer-readable medium and execute the instructions in hardware using one or more processors to perform the techniques of the present disclosure. . Each of 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 coupled encoder/decoder (CODEC) in the respective device. there is. A device comprising video encoder 200 and/or video decoder 300 may include an integrated circuit, a microprocessor, and/or a wireless communication device, such as a cellular telephone.

Video encoder 200 and video decoder 300 may implement video coding standards such as ITU-T H.265, also referred to as High Efficiency Video Coding (HEVC), or extensions thereof, such as multi-view and/or scalable video coding. It may also work depending on extensions. Alternatively, video encoder 200 and video decoder 300 may operate according to other proprietary or industry standards, such as ITU-T H.266, also referred to as Versatile Video Coding (VVC). In other examples, video encoder 200 and video decoder 300 may encode data according to a proprietary video codec/format, such as AOMedia Video 1 (AV1), an extension of AV1, and/or a successor to AV1 (e.g., AV2). It might work. In other examples, video encoder 200 and video decoder 300 may operate according to another proprietary format or industry standard. However, the techniques of this disclosure are not limited to any particular coding standard or format. In general, video encoder 200 and video decoder 300 may be configured to perform the techniques of this disclosure in conjunction with any video coding techniques that use an SEI message to determine video orientation and/or picture quality metrics. there is.

In general, video encoder 200 and video decoder 300 may perform block-based coding of pictures. The term “block” generally refers to a structure containing data to be processed (eg, to be encoded, decoded, or otherwise used in an encoding and/or decoding process). For example, a block may include a two-dimensional matrix of samples of luminance and/or chrominance data. In general, video encoder 200 and video decoder 300 may code video data represented in YUV (e.g., Y, Cb, Cr) format. That is, rather than coding red, green, and blue (RGB) data for samples of a picture, video encoder 200 and video decoder 300 may code luminance and chrominance components, where chrominance The components may include both red-tinted and blue-tinted chrominance components. In some examples, video encoder 200 converts received data in RGB format to a YUV representation prior to encoding, and video decoder 300 converts the YUV representation to RGB format. Alternatively, pre- and post-processing units (not shown) may perform these transformations.

This disclosure may generally refer to coding (e.g., encoding and decoding) of pictures to include the process of encoding or decoding data of the picture. Similarly, this disclosure may refer to coding of blocks of a picture to include processes for encoding or decoding data for the blocks, such as prediction and/or residual coding, for example. An encoded video bitstream typically contains a set of values for syntax elements that represent coding decisions (eg, coding modes) and partitioning of pictures into blocks. Accordingly, references to coding a picture or block should generally be understood as coding values for syntactic elements that form the picture or block.

HEVC defines various blocks including coding units (CUs), prediction units (PUs) and transform units (TUs). According to HEVC, a video coder (such as video encoder 200) partitions a coding tree unit (CTU) into CUs according to a quadtree structure. That is, the video coder partitions the CTUs and CUs into four identical non-overlapping squares, and each node of the quadtree has either 0 or 4 child nodes. Nodes without child nodes may be referred to as “leaf nodes,” and the CUs of such leaf nodes may include one or more PUs and/or one or more TUs. The video coder may further partition PUs and TUs. For example, in HEVC, the residual quadtree (RQT) represents the partitioning of TUs. In HEVC, PUs represent inter prediction data, while TUs represent residual data. CUs that are intra predicted include intra prediction information such as intra mode indication.

As another example, video encoder 200 and video decoder 300 may be configured to operate in accordance with VVC. In accordance with VVC, a video coder (e.g., video encoder 200) partitions a picture into a plurality of coding tree units (CTUs). Video encoder 200 may partition CTUs according to a tree structure, such as a quadtree-binary tree (QTBT) structure or a Multi-Type Tree (MTT) structure. The QTBT structure eliminates the concept of multiple partition types, such as the separation between CUs, PUs, and TUs in HEVC. The QTBT structure includes two levels: a first level partitioned according to quadtree partitioning, and a second level partitioned according to binary tree partitioning. The root node of the QTBT structure corresponds to CTU. Leaf nodes of binary trees correspond to coding units (CUs).

In an MTT partitioning structure, blocks may be partitioned using quadtree (QT) partitions, binary tree (BT) partitions, and one or more types of triple tree (TT) (also called triple tree (TT)) partitions. A triple or ternary tree partition is a partition in which a block is divided into three sub-blocks. In some examples, a triple or ternary tree partition divides a block into three sub-blocks without splitting the original block through its center. Partitioning types in MTT (eg, QT, BT, and TT) may be symmetric or asymmetric.

When operating according to the AV1 codec, video encoder 200 and video decoder 300 may be configured to code video data into blocks. In AV1, the largest coding block that can be processed is referred to as a superblock. In AV1, a superblock can be either 128x128 luma samples or 64x64 luma samples. However, in subsequent video coding formats (eg, AV2), a superblock may be defined by different (eg, larger) luma sample sizes. In some examples, a superblock is the top level of a block quadtree. Video encoder 200 may further partition the superblock into smaller coding blocks. Video encoder 200 may partition superblocks and other coding blocks into smaller blocks using square or non-square partitioning. Non-square blocks may include N/2xN, NxN/2, N/4xN, and NxN/4 blocks. Video encoder 200 and video decoder 300 may perform separate prediction and transform processes for each of the coding blocks.

AV1 also defines tiles of video data. A tile is a rectangular array of superblocks that may be coded independently from other tiles. That is, video encoder 200 and video decoder 300 may each encode and decode coding blocks within a tile without using video data from other tiles. However, video encoder 200 and video decoder 300 may perform filtering across tile boundaries. Tiles may or may not be uniform in size. Tile-based coding may enable parallel processing and/or multi-threading for encoder and decoder implementations.

In some examples, video encoder 200 and video decoder 300 may use a single QTBT or MTT structure to represent each of the luminance and chrominance components, while in other examples, video encoder 200 and video decoder 300 may use a single QTBT or MTT structure to represent each of the luminance and chrominance components. Decoder 300 may be configured to use two or more QTBT or MTT structures, such as one QTBT/MTT structure for a luminance component and another QTBT/MTT structure for both chrominance components (or a QTBT/MTT structure for each chrominance component). Two QTBT/MTT structures) can also be used.

Video encoder 200 and video decoder 300 may be configured to use quadtree partitioning, QTBT partitioning, MTT partitioning, superblock partitioning, or other partitioning structures.

In some examples, a CTU is a coding tree block (CTB) of luma samples, two corresponding CTBs of chroma samples of a picture with three sample arrays, or three separate color planes and syntax used to code the samples. Contains the CTB of samples of a picture or monochrome picture coded using the structures. A CTB may be an NxN block of samples for some value of N such that the division of the component into CTBs is partitioned. A component is a single sample or array from one of three arrays (luma and two chroma) that make up an image in 4:2:0, 4:2:2, or 4:4:4 color format, or monochrome. A format is a single sample or array of arrays that make up an image. In some examples, a coding block is an NxN block of samples for some values of M and N such that the division of the CTB into coding blocks is a partitioning.

Blocks (eg, CTUs or CUs) may be grouped in various ways in a picture. As an example, a brick may refer to a rectangular area of CTU rows within a specific tile in an image. A tile may be a rectangular area of CTUs within a particular tile row and a particular tile column in a picture. A tile row refers to a rectangular area of CTUs with a height equal to the height of the picture and a width specified by syntax elements (e.g., as in a picture parameter set). A tile row refers to a rectangular region of CTUs with a height specified by syntax elements (e.g., as in a picture parameter set) and a width equal to the width of the picture.

In some examples, a tile may be partitioned into multiple bricks, each of which may contain one or more CTU rows within the tile. A tile that is not partitioned into multiple bricks may also be referred to as a brick. However, bricks that are a true subset of tiles may not be referred to as tiles. Bricks in an image may also be arranged in slices. A slice may be an integer number of bricks of a picture that may be contained exclusively in a single Network Abstraction Layer (NAL) unit. In some examples, a slice contains only a contiguous sequence of multiple complete tiles or complete bricks of one tile.

This disclosure uses “NxN” and “N by N” interchangeably to refer to the sample dimensions of a block (such as a CU or other video block) in terms of the vertical and horizontal dimensions, e.g., 16x16 samples or 16 by 16. You can also use samples. Typically, a 16x16 CU will have 16 samples in the vertical direction (y = 16) and 16 samples in the horizontal direction (x = 16). Likewise, an NxN CU generally 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 may be arranged into rows and columns. Additionally, CUs do not necessarily have to have the same number of samples in the horizontal direction as in the vertical direction. For example, CUs may contain NxM samples, where M is not necessarily equal to N.

Video encoder 200 encodes video data for CUs that represent prediction and/or residual information, and other information. Prediction information indicates how the CU will be predicted to form a prediction block for the CU. Residual information generally represents sample-by-sample differences between samples of a CU before encoding and a prediction block.

To predict a CU, video encoder 200 may form a prediction block for the CU, generally through inter-prediction or intra-prediction. Inter prediction generally refers to predicting a CU from data of a previously coded picture, while intra prediction generally refers to predicting a CU from previously coded data of the same picture. To perform inter prediction, video encoder 200 may use one or more motion vectors to generate a prediction block. Video encoder 200 may generally perform a motion search to identify a reference block that closely matches a CU, e.g., with respect to the difference between the CU and the reference block. Video encoder 200 is capable of calculating sum of absolute differences (SAD), sum of squared differences (SSD), mean absolute difference (MAD), and mean squared differences. ; MSD), or other such difference calculations to determine whether the reference block closely matches the current CU. In some examples, video encoder 200 may predict the current CU using one-way prediction or two-way prediction.

Some examples of VVC also provide an affine motion compensation mode, which may be considered an inter prediction mode. In an affine motion compensation mode, video encoder 200 may determine two or more motion vectors representing non-translational motion, such as zooming in or out, rotation, perspective motion, or other irregular motion types.

To perform intra prediction, video encoder 200 may select an intra prediction mode to generate a prediction block. Some examples of VVC provide 67 intra-prediction modes, including planar and DC modes, as well as various directional modes. In general, video encoder 200 selects an intra prediction mode that describes neighboring samples for a current block (e.g., a block of a CU) for which samples of the current block will be predicted. Such samples are generally the top, top left of the current block in the same picture as the current block, assuming that video encoder 200 codes the CTUs and CUs in raster scan order (left to right, top to bottom). It may be on the side or on the left.

Video encoder 200 encodes data indicating the prediction mode for the current block. For example, for an inter prediction mode, video encoder 200 may encode data indicating which of the various available inter prediction modes is used, as well as motion information for the corresponding mode. For one-way or two-way inter prediction, for example, video encoder 200 may encode motion vectors using advanced motion vector prediction (AMVP) or merge mode. Video encoder 200 may encode motion vectors for an affine motion compensation mode using similar modes.

AV1 includes two general techniques for encoding and decoding coding blocks of video data. Two common techniques are intra prediction (eg, intra frame prediction or spatial prediction) and inter prediction (eg, inter frame prediction or temporal prediction). In the context of AV1, when predicting blocks of the current frame of video data using intra prediction mode, video encoder 200 and video decoder 300 do not use video data from other frames of video data. For most intra prediction modes, video encoder 200 encodes blocks of the current frame based on the difference between sample values in the current block and predicted values generated from reference samples in the same frame. Video encoder 200 determines predicted values generated from reference samples based on intra prediction mode.

Following prediction, such as intra-prediction or inter-prediction of a block, video encoder 200 may calculate residual data for the block. Residual data, such as a residual block, represents sample-by-sample differences between a block and a prediction block for the block, formed using a corresponding prediction mode. Video encoder 200 may apply one or more transforms to the residual block to generate transformed data in the transform domain instead of the sample domain. For example, video encoder 200 may apply a discrete cosine transform (DCT), integer transform, wavelet transform, or conceptually similar transform to the residual video data. Additionally, video encoder 200 may apply a secondary transform subsequent to the first transform, such as a mode dependent non-separable secondary transform (MDNSST), signal dependent transform, Karhunen-Loeve transform (KLT), etc. Video encoder 200 generates transform coefficients following application of one or more transforms.

As mentioned above, following any transforms to generate a transform coefficient, video encoder 200 may perform quantization of the transform coefficient. Quantization generally refers to a process in which transform coefficients are quantized to possibly reduce the amount of data used to represent the transform coefficients, thereby providing additional compression. By performing a quantization process, video encoder 200 may reduce the bit depth associated with some or all of the transform coefficients. For example, video encoder 200 may round down n-bit values to m-bit values during quantization, where n is greater than m. In some examples, to perform quantization, video encoder 200 may perform a bitwise right-shift of the value to be quantized.

Following quantization, video encoder 200 may scan the transform coefficients to generate a one-dimensional vector from a two-dimensional matrix containing the quantized transform coefficients. The scan may be designed to place higher energy (and therefore lower frequency) transform coefficients in front of the vector and lower energy (and therefore higher frequency) transform coefficients behind the vector. In some examples, video encoder 200 may utilize a predefined scan order to scan the quantized transform coefficients to generate a serialized vector and then entropy encode the quantized transform coefficients of the vector. In other examples, video encoder 200 may perform adaptive scan. After scanning the quantized transform coefficients to form a one-dimensional vector, video encoder 200 may entropy encode the one-dimensional vector, for example, according to context adaptive binary arithmetic coding (CABAC). Video encoder 200 may also entropy encode values for syntax elements that describe metadata associated with the encoded video data for use by video decoder 300 in decoding the video data.

To perform CABAC, video encoder 200 may assign a context within a context model to the symbol to be transmitted. Context may relate to, for example, whether neighboring values of a symbol are zero values. The probability determination may be based on the context assigned to the symbol.

Video encoder 200 may transmit syntax data, such as block-based syntax data, picture-based syntax data, and sequence-based syntax data, to video decoder 300, e.g., in a picture header, block header, slice header, or other It may additionally be generated from syntax data, such as sequence parameter set (SPS), picture parameter set (PPS), or video parameter set (VPS). Video decoder 300 may similarly decode such syntax data to determine how to decode the corresponding video data.

In this way, video encoder 200 encodes encoded video data, e.g., syntax elements that describe the partitioning of a picture into blocks (e.g., CUs) and bits that contain prediction and/or residual information for the blocks. You can also create streams. Ultimately, video decoder 300 may receive the bitstream and decode the encoded video data.

In general, video decoder 300 performs a process opposite to that performed by video encoder 200 to decode encoded video data in a bitstream. For example, video decoder 300 may use CABAC to decode values for syntax elements of a bitstream, substantially similar to the CABAC encoding process of video encoder 200, but in a contrasting manner. Syntax elements may define partitioning information for the partitioning of a picture into CTUs, and partitioning of each CTU according to a corresponding partition structure, such as a QTBT structure, thereby defining the CUs of the CTU. Syntax elements may further define prediction and residual information for blocks (eg, CUs) of video data.

Residual information may be represented by, for example, quantized transform coefficients. Video decoder 300 may inverse quantize and inverse transform the quantized transform coefficients of a block to reproduce the residual block for the block. Video decoder 300 uses the signaled prediction mode (intra or inter prediction) and associated prediction information (e.g., motion information for inter prediction) to form a prediction block for the block. Video decoder 300 may then combine the prediction block and the residual block (on a per-sample basis) to reproduce the original block. Video decoder 300 may perform additional processing, such as performing a deblocking process to reduce visual artifacts along the boundaries of a block.

This disclosure may generally refer to “signaling” certain information, such as syntax elements. The term “signaling” generally refers to values and/or for syntax elements used to decode encoded video data. It may also refer to the communication of other data. That is, video encoder 200 may signal values for syntax elements in a bitstream. In general, signaling refers to generating a value in a bitstream. As noted, source device 102 may store the bitstream in non-real-time or substantially real-time, as may occur when storing syntax elements in storage device 112 for later retrieval by destination device 116. It may also be transmitted to the destination device 116.

In general, this disclosure describes techniques for coding video data. In particular, this disclosure describes techniques for decoding SEI messages. SEI messages of the present disclosure may include syntax elements that indicate the orientation of the image. In another example, the SEI message may include syntax elements representing image quality metrics. A video decoder or other device may decode the SEI message and process an image of the video data according to the SEI message.

The Versatile Supplementary Enhancement Information (VSEI) standards (e.g., ITU-T H.274 and ISO/IEC 23002-7) specify video usability information (VUI) messages and some SEI messages to be used with VVC bitstreams. The SEI message allows the video encoder 200 to include metadata in the bitstream that is not necessary for accurate decoding of sample values of the output picture, but can be used for various other purposes. A video encoder may be configured to include any number of SEI Network Abstraction Layer (NAL) units in an access unit, and each SEI NAL unit may include one or more SEI messages. Specifications and systems that use VVC may specify that the encoder generate certain SEI messages or may define special handling of certain types of received SEI messages.

ISO/IEC JTC 1/SC 29/WG 11 N 18277, “Information technology ― High efficiency coding and media delivery in heterogeneous environments ― Part 2: High Efficiency Video Coding,” 2019 (“HEVC”) is a decoded video that is cropped before display. Specifies a display orientation SEI message to inform the decoder (e.g., video decoder 300) of the recommended transformation to be applied to the image. The syntax structure of HEVC's display orientation SEI message is shown in Table 1 below.

Table 1 Display Orientation SEI Message Syntax

As shown in Table 1, HEVC's display orientation SEI message allows the display of horizontal flip (hor_flip), vertical flip (ver_flip), and anticlockwise rotation (anticlockwise_rotation) transformations.

3GPP has technical specifications (TS) 26.114, “IP Multimedia Subsystem (IMS); Multimedia telephony; Media handling and interaction,” 2021 specifies coordination of video orientation (CVO). The CVO signals the current orientation of the image captured on the transmitter side (e.g., at source device 102) to a receiver (e.g., destination device 116) for appropriate rendering and display. CVO information for low rotation granularity is carried in bytes in the following format to support horizontal flips and 90-degree rotations:

LSB represents the least significant bit.

CVO information for higher rotational granularity is conveyed in bytes in the following format:

Some current examples of the VSEI standard do not support orientation metadata. The HEVC display orientation SEI message does not take into account the frame-packing case, where rotation will be applied to each component image instead of the entire image. Figure 2 shows an example of display rotation of a frame packed image where each component image must be rotated separately. As shown in Figure 2, picture 150 includes two component pictures (e.g., a left view picture and a right view picture for stereoscopic video). Using the techniques of this disclosure, video encoder 200 includes a transform type syntax element that instructs video decoder 300 to perform a rotation transform on each of the component pictures to achieve transformed picture 152. You can also send a code and SEI message.

Example VSEI Region-wise Packing (RWP) SEI message provides information to enable remapping of color samples of a cropped decoded picture onto projected pictures. However, the RWP SEI message is used to indicate that omnidirectional video projection is to be applied to the image. RWP SEI messages with rwp_cancel_flag equal to 0 will not be present in the Coded Layered Video Sequence (CLVS) applied to the picture.

Image quality metrics are used to evaluate image quality and coding performance. ISO/IEC 23001-10, ”Information technology ― MPEG systems technologies ― Part 10: Carriage of Timed Metadata Metrics of Media in ISO Base Media File Format,” 2015, peak signal-to-peak signal in ISOBMFF (ISO/IEC Base Media File Format) Specifies the carriage of timed metadata metrics of the media, such as noise ratio (PSNR), structural similarity index measure (SSIM), video quality metric (VQM), and mean opinion score (MOS). Image quality-related rankings are based on OMAF, ISO/IEC JTC1/SC29/WG11 N19042, “Text of ISO/IEC DIS 23090-2 2 ^nd edition OMAF,” 2020, to facilitate quality-dependent viewport switching and measurement of immersive media metrics. and Immersive Media Metrics (IMM), ISO/IEC JTC1/SC29/WG3 N0073, “IS of ISO/IEC 23090-6 Immersive Media Metrics,” 2020. Some picture quality metrics, such as PSNR and SSIM, can only be obtained at the encoder side. SEI messages carrying this information can provide relevant information to system applications.

Image orientation SEI message

According to an example of the disclosure, video encoder 200 is configured to generate and signal an image orientation SEI message that includes one or more syntax elements shown in Table 2 below. In particular, video encoder 200 may be configured to generate and encode a transform type syntax element (e.g., por_transform_type), where the transform type syntax element indicates a transform to be applied to the image, among a plurality of transforms. Video encoder 200 may also be configured to generate and encode one or more of the other syntax elements and flags listed in Table 2. Video decoder 300 may be configured to receive an image orientation SEI message and may process and/or display the image according to syntax elements included therein. For example, video decoder 300 may be configured to apply a transform indicated by a transform type syntax element to a decoded picture.

Table 2 Image orientation SEI message syntax

Typically, a picture orientation (POR) SEI message provides information to inform the video decoder 300 of the recommended transformation to apply to the decoded picture prior to display. In some examples, the decoded picture may be a cropped picture.

A value of 1 for the syntax element por_cancel_flag indicates that the current SEI message cancels the persistence of any previous POR SEI message in the output order. If the value of the syntax element por_cancel_flag is 0, it indicates that POR information follows.

The value of the syntax element por_persistence_flag specifies the persistence of the POR SEI message for the current layer.

The value of the syntax element por_persistence_flag is If 0, specifies that the POR SEI message applies only to the currently decoded image.

The value of the syntax element por_persistence_flag is If 1, specifies that the POR SEI message is applied to the currently decoded picture and persists for all subsequent pictures in the current layer in output order until one or more of the following conditions are true:

- A new CLVS of the current layer starts.

- The bitstream ends.

- In the access unit (AU) associated with the POR SEI message, the picture in the current layer is output following the current picture in output order.

The value of the syntax element por_constituent_picture_matching_flag is 1 to specify that this SEI message is applied individually to each component picture and that the stereoscopic frame packing format is indicated by the frame packing arrangement SEI message. The value of the syntax element por_constituent_picture_matching_flag is A value of 0 specifies that this SEI message applies to cropped decoded images.

When either of the following conditions is true, the value of the syntax element por_constituent_picture_matching_flag will be equal to 0:

- StereoFlag is 0.

- StereoFlag is 1 and fp_arrangement_type is 5.

If the value of StereoFlag is 0, it indicates that there is no frame packing arrangement SEI message with fp_arrangement_cancel_flag 0 applied to the image. If the value of StereoFlag is 1, it indicates that the associated image is a frame packing image.

A value of the syntax element fp_arrangement_type of 5 indicates that the component plane of the output cropped decoded picture in the output order forms temporal interleaving of alternating first and second component frames.

The value of the syntax element por_transform_type specifies the transformation that may be applied to the image (e.g. rotation, mirroring, or a combination of rotation and mirroring). Note that in some examples, mirroring may be referred to as flipping. If the transform indicated by por_transform_type specifies both rotation and mirroring, video decoder 300 may be configured to apply the rotation transform before applying mirroring, and vice versa. Example values for por_transform_type are specified in Table 3 below. Values 8 to 31 of por_transform_type are reserved for future use by ITU-T|ISO/IEC.

Table 3 por_transform_type values

The specific values in Table 3 are examples only. In other examples, more or fewer conversion types may be specified. Additionally, transformations may be specified in a different order than shown in Table 3.

3 is a conceptual diagram illustrating example transformation types. In the example of Table 3, when the transform syntax element has a value of 0, video decoder 300 may not apply the transform. Figure 3 shows the original image 160 to which no transformation has been applied. The different transformation types in Figure 3 will be shown with reference to the original image 160. When the transform syntax element has the value of 1, video decoder 300 may apply a horizontal mirroring transform to original picture 160 to obtain picture 162. Horizontal mirroring may also be referred to as horizontal flipping. When the transform syntax element has a value of 2, video decoder 300 may apply a 180-degree, counterclockwise rotation transform to original picture 160 to obtain picture 164. When the transform syntax element has a value of 3, video decoder 300 may apply a 180-degree, counterclockwise rotation transform to original picture 160, followed by a horizontal mirroring transform to obtain picture 166.

When the transform syntax element has a value of 4, video decoder 300 may apply a 90-degree, counterclockwise rotation transform to original picture 160, followed by a horizontal mirroring transform to obtain picture 168. When the transform syntax element has a value of 5, video decoder 300 may apply a 90-degree, counterclockwise rotation transform to original picture 160 to obtain picture 170. When the transform syntax element has a value of 6, video decoder 300 may apply a 270-degree, counterclockwise rotation transform to original picture 160, followed by a horizontal mirroring transform to obtain picture 172. When the transform syntax element has a value of 7, video decoder 300 may apply a 270-degree, counterclockwise rotation transform to original picture 160 to obtain picture 174.

4 is a flow chart illustrating an example process for coding an image orientation supplemental enhancement information message. 4 illustrates both the encoding and decoding processes of this disclosure. As shown in FIG. 4, the encoding process may be performed by source device 102, which includes video encoder 200. The decoding process may be performed by destination device 116, which includes video decoder 300.

In one example of this disclosure, source device 102 may be configured to receive an image (400). Source device 102 may also be configured to encode a picture (e.g., using video encoder 200) and transmit the encoded video bitstream to destination device 116. Source device 102 may also be configured to determine a recommended conversion type for the image (402). The recommended conversion type may be a conversion type among a plurality of conversion types. Source device 102 may be further configured to encode a picture orientation message including a transformation type syntax element, where the transformation type syntax element indicates a transformation to be applied to the picture, among a plurality of transformations (404).

Destination device 116 may be configured to receive images (410). Destination device 116 may also be configured to decode a picture (e.g., using video decoder 300). Destination device 116 may also decode a picture orientation message that includes a transformation type syntax element, where the transformation type syntax element indicates a transformation to be applied to the picture, among a plurality of transformations (412). The destination device 116 may be further configured to apply 414 a transformation to the image according to a transformation type syntax element to form a transformed image and display 416 the transformed image.

In one example of this disclosure, the image orientation message includes an image orientation SEI message. In another example, the image orientation message includes an image orientation open bitstream unit (OBU).

As described above, the plurality of transformations include two or more of a rotation transformation, a mirroring transformation, or a combination of rotation and mirroring transformations. In a more specific example, the plurality of transformations include a first transformation comprising a horizontal mirroring transformation, a second transformation comprising a 180 degree counterclockwise rotation transformation, and a third transformation comprising a 180 degree counterclockwise transformation followed by a horizontal mirroring transformation. , a fourth transformation comprising a 90 degree counterclockwise transformation followed by a horizontal mirroring transformation, a fifth transformation comprising a 90 degree counterclockwise transformation, a sixth transformation comprising a 270 degree counterclockwise transformation followed by a horizontal mirroring transformation, and a seventh transformation comprising a 270 degree counterclockwise transformation. In a further example, the conversion type syntax element further includes a value indicating that no conversion is applied.

In some examples, video encoder 200 may signal high rotational granularity in the SEI message. Higher rotational granularity and mirroring may be applied to each component image. In general, a high rotational particle size may indicate a relatively small degree of rotation. For example, high rotational granularity may include rotating the image by an angle of less than 90 degrees. In cases where each component picture may be rotated differently, video encoder 200 may specify a separate orientation transformation type or high rotation granularity in the SEI message or other metadata type, each of which applies to one component picture. there is.

In some examples, video encoder 200 may specify a component picture matching flag in CVO signaling. The component image matching flag may indicate the rotational granularity applied to each component image.

Image Quality Metrics SEI Message

According to another example of the disclosure, video encoder 200 generates a picture quality metrics message (e.g., an SEI message and/or other packetized structure) that includes one or more of the syntax elements shown in Table 4 below, and It is configured to signal. Video decoder 300 is configured to receive an image quality metrics SEI message and may process and/or display the image according to syntax elements included therein. For example, destination device 116 and/or video decoder 300 may be configured to apply one or more post-processing techniques to the decoded picture according to quality metrics indicated in the picture quality metrics SEI message. An example post-processing technique may include upscaling the decoded picture based on picture quality. In other examples, video decoder 300 may be configured to use a quality metric to select a particular picture to use for inter prediction. For example, when multiple versions of the same picture are available, video decoder 300 selects the picture with the highest quality metrics (e.g., lowest signal-to-noise ratio) for use as a reference picture in inter prediction. It can also be configured to select.

Table 4 is an example of an image quality metrics SEI message. Picture Quality Metrics SEI message provides quality metrics for each color component of the currently decoded picture.

Table 4 Image Quality Metrics SEI Message Syntax

The value of the syntax element pqm_metric_type indicates the type of quality metric associated with the component specified in Table 5. The values 4 to 127 of pqm_metric_type are ITU-T | Reserved for future use by ISO/IEC and will not be present in payload data conforming to this version of this specification.

Table 5 Interpretation of pqm_metric_type

The PSNR quality metric type is Peak Signal to Noise Ratio. The SSIM quality metric type is Structural Similarity Index. The MS-SSIM quality metric is a multiscale structural similarity index. The VQM quality metric type is video quality metric.

If the value of the syntax element pqm_single_component_flag is 1, it specifies that the image associated with the image quality metrics SEI message contains a single color component. If the value of the syntax element pqm_single_component_flag is 0, it specifies that the image associated with the image quality metrics SEI message contains three color components. The value of pqm_single_component_flag will be the same as (ChromaFormatIdc = = 0).

The value of the syntax element pqm_psnr [ cIdx ] specifies the value of PSNR. The corresponding PSNR of the color component cIdx of the decoded picture is derived (expressed in floating point) as follows:

PSNR = pqm_psnr[　cIdx　] / 100; The exception is that for pqm_psnr[　cIdx　] equal to 0, PSNR = infinity.

The value of the syntax element pqm_ssim[ cIdx ] specifies the value of SSIM. The corresponding SSIM of the color component cIdx of the decoded picture is derived (expressed in floating point) as follows:

SSIM = ( pqm_ssim[　cIdx　] - 127 ) / 128

The value of the syntax element pqm_msssim [ cIdx ] specifies the value of MS-SSIM. The corresponding MS-SSIM of the color component cIdx of the decoded picture is derived (expressed in floating point) as follows:

MS SSIM = ( pqm_msssim[　cIdx　] - 127 ) / 128

The value of the syntax element pqm_vqm[ cIdx ] specifies the value of SSIM. The corresponding VQM of the color component cIdx of the decoded picture is derived (expressed in floating point) as follows:

VQM = pqm_vqm[　cIdx　] / 50

Picture Quality Metrics SEI messages may convey other quality-related metrics, such as Perceptual Evaluation of Video Quality (PEVQ), Mean Opinion Score (MOS), and/or other picture quality metrics.

In some examples, the picture quality metrics SEI message may specify quality metrics for each component picture when the picture is associated with a stereoscopic frame packing arrangement SEI message. The image quality metrics SEI message may specify quality metrics for each region when the image is associated with a region-specific frame packing SEI message. Additional syntax elements may be added to the SEI message to indicate whether image quality metrics exist for each component image or each region.

In another example, an image quality metrics SEI message may convey quality metrics of one or multiple subpictures or regions of interest (ROI) of an image associated with the SEI message. Syntax elements indicating the number of subpictures or ROIs, syntax elements indicating subpicture or ROI positions, and/or syntax elements indicating subpicture or ROI sizes may also be specified in the SEI message.

Additional quality metrics, such as weighted PSNR (PSNR) and weighted-to-spherically uniform PSNR (WS-PSNR), may be included in the SEI message to indicate the quality of high dynamic range (HDR) and 360 video content.

Another example video metrics SEI message format is provided in Table 6.

Table 6 Image quality metrics SEI message syntax

The above picture metrics SEI message provides quality metrics of the currently decoded picture.

The value of the syntax element pqm_cnt_minus1 plus 1 specifies the number of luma component quality metrics indicated by the SEI message.

The value of the syntax element pqm_type [i] indicates the ith quality metric type associated with the decoded picture or video sequence, as specified in Table 7.

Table 7 Interpretation of pqm_type

PSNR _sequence , The wPSNR _sequence , and WS-PSNR _sequence quality metric types represent the PSNR, wPSNR, and WS-PSNR of multiple pictures for the sequence, respectively.

The value of the syntax element pqm_value [i] specifies the value of the ith quality metric. The value of the syntax element pqm_type is If 0, the stored 16-bit unsigned integer pqm_value is interpreted as a PSNR value (in dB) (expressed as floating point) as follows, with the exception that for pqm_value values equal to 0, the PSNR is infinity.

; Here M is an integer (e.g. 100).

The value of the syntax element pqm_type is If 1, the stored 16-bit unsigned integer pqm_value is interpreted as a wPSNR value (in dB) (expressed as floating point) as follows, with the exception that for pqm_value values equal to 0, wPSNR is infinite.

; Here M is an integer (e.g. 100).

The value of the syntax element pqm_type is If 2, the stored 16-bit unsigned integer pqm_value is interpreted as a WS-PSNR value (in dB) (expressed as floating point) as follows, with the exception that for pqm_value values equal to 0, the WS-PSNR is infinite.

; Here M is an integer (e.g. 100).

The value of the syntax element pqm_type is If 3, the quality metric represents the average luma PSNR of the CLVS to which the associated picture belongs. The 16-bit unsigned integer pqm_value is interpreted as the result of a sequence-level PSNR quality metric (in dB) and derived (expressed as floating point) as follows, with the exception that for pqm_value values equal to 0, the PSNR is infinite. ; Here M is an integer (e.g. 100).

The value of the syntax element pqm_type is If 4, the quality metric represents the average luma-weighted PSNR of the CLVS to which the associated picture belongs. The 16-bit unsigned integer pqm_value is interpreted as a sequence-level wPSNR value (in dB) (expressed as floating point), with the exception that for pqm_value values equal to 0, wPSNR is infinite.

; Here M is an integer (e.g. 100).

The value of the syntax element pqm_type is If 5, the quality metric represents the average luma WS-PSNR of the CLVS to which the associated picture belongs. The 16-bit unsigned integer pqm_value is interpreted as a sequence-level WS-PSNR value (in dB) (expressed as floating point), with the exception that for pqm_value values equal to 0, WS-PSNR is infinite.

; Here M is an integer (e.g. 100).

In another example, additional quality metric types may be included in the SEI message to indicate an average quality metric applied to multiple video frames. A first syntax element may be specified in the SEI message to indicate that the quality metric specified in the SEI message applies to the associated picture and persists for all subsequent pictures in the current layer in output order. A second syntax element may be specified in the SEI message to cancel persistence of any previous quality metrics in the output order.

In another example, when an average quality metric, such as sequence level PSNR, is present for any picture in CLVS, an associated picture quality SEI message will be present for the first picture in CLVS. The average picture metric of all SEI messages applying to the same CLVS will have the same content.

FIG. 5 is a flow chart illustrating an example process for coding a quality metrics replenishment enhancement information message. Figure 5 illustrates both the encoding and decoding processes of this disclosure. As shown in FIG. 5, the encoding process may be performed by source device 102, which includes video encoder 200. The decoding process may be performed by destination device 116, which includes video decoder 300.

In one example of this disclosure, source device 102 may be configured to receive an image (500). Source device 102 may also be configured to encode a picture (e.g., using video encoder 200) and transmit the encoded video bitstream to destination device 116. Source device 102 may also be configured to determine a quality metric for an image (502). Source device 102 may be further configured to encode a quality metrics message including a quality metrics syntax element, where the quality metrics syntax element indicates a value of a quality metric associated with the image (504).

In a further example of the present disclosure, source device 102 may be further configured to encode a quality metric type syntax element within a quality metrics message, wherein the quality metric type syntax element is a quality metric type syntax element, among a plurality of quality metric types. Indicates the type of quality metric, indicated by . In one example, the plurality of quality metrics types include peak signal-to-noise ratio (PSNR). In another example, the plurality of types of quality metrics include peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), multiscale structural similarity index (MS-SSIM), video quality metric (VQM), and weighted PSNR (wPSNR). , weighted to spherically uniform PSNR (WS-PSNR), sequence PSNR, sequence wPSNR, or sequence WS-PSNR. In the above example, the quality metric syntax element represents the value of the quality metric indicated by the quality metric type syntax element.

Destination device 116 may be configured to receive images (510). Destination device 116 may also be configured to decode a picture (e.g., using video decoder 300). Destination device 116 may also decode a quality metrics message that includes a quality metrics syntax element, where the quality metrics syntax element indicates a value of a quality metric associated with the image (512). The destination device 116 may be further configured to apply 514 post-processing techniques to the image according to the values of the quality metrics to form a processed image, and to display 516 the processed image.

In a further example of the present disclosure, destination device 116 may be further configured to decode a quality metric type syntax element in a quality metrics message, wherein the quality metric type syntax element is a quality metric type syntax element, among a plurality of quality metric types. Indicates the type of quality metric, indicated by . In one example, the plurality of quality metrics types include peak signal-to-noise ratio (PSNR). In another example, the plurality of types of quality metrics include peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), multiscale structural similarity index (MS-SSIM), video quality metric (VQM), and weighted PSNR (wPSNR). , weighted to spherically uniform PSNR (WS-PSNR), sequence PSNR, sequence wPSNR, or sequence WS-PSNR. In the above example, the quality metric syntax element represents the value of the quality metric indicated by the quality metric type syntax element.

In one example of this disclosure, the quality metrics message includes a quality metrics SEI message. In another example, the quality metrics message includes a quality metrics open bitstream unit (OBU).

In another example of the present disclosure, source device 102 and/or destination device 116 may be configured to code a second quality metrics message that includes a second quality metrics syntax element, wherein the second quality metrics syntax element represents a second value of a second quality metric related to a sub-picture or region of interest of the image.

For purposes of explanation, the above techniques are described in the context of VVC (ITU-T H.266, under development), and HEVC (ITU-T H.265). However, the techniques of this disclosure may be performed by video encoding devices configured with other video coding standards and video coding formats, such as AV1, future versions of AV1, and successors to the AV1 video coding format. For example, in contrast to being an SEI message, the message may be packetized data, such as an open bitstream unit (OBU) that includes at least some of the metadata described in this disclosure. As an example, some or all of the above-described syntax included within a picture orientation SEI message may be included within a picture orientation OBU such that the picture orientation OBU includes a cancellation flag, persistence flag, component picture matching flag, or transformation type syntax element. As another example, any or all of the syntax described above included within an image quality metrics SEI message may be included within an image quality metrics OBU such that the image quality metrics OBU includes one or more syntax elements representing quality metrics of the image.

6 is a block diagram illustrating an example video encoder 200 that may perform the techniques of this disclosure. 6 is provided for illustrative purposes and should not be considered limiting of the techniques as generally illustrated and described in this disclosure. For purposes of explanation, this disclosure describes a video decoder 200 according to the techniques of VVC (ITU-T H.266, under development) and HEVC (ITU-T H.265). However, the techniques of this disclosure may also be performed by video encoding devices configured with other video coding standards and video coding formats, such as AV1 and successors to the AV1 video coding format.

In the example of Figure 6, video encoder 200 includes video data memory 230, mode selection unit 202, residual generation unit 204, transform processing unit 206, quantization unit 208, and 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. 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 Any or all of unit 214, filter unit 216, DPB 218, and entropy encoding unit 220 may be implemented in one or more processors or processing circuitry. For example, units of video encoder 200 may be implemented as one or more circuits or logic elements as part of a hardware circuit or as part of a processor, ASIC, or FPGA. Moreover, video encoder 200 may include additional or alternative processors or processing circuitry to perform these and other functions.

Video data memory 230 may store video data to be encoded by components of video encoder 200. Video encoder 200 may receive video data stored in video data memory 230, for example, from video source 104 (Figure 1). DPB 218 may act as a reference picture memory to store reference video data for use in prediction of subsequent video data by video encoder 200. Video data memory 230 and DPB 218 may include various memory devices, such as DRAM, including synchronous dynamic random access memory (SDRAM), magnetoresistive RAM (MRAM), and resistive RAM (RAM). RAM; RRAM), or any of other types of memory devices. Video data memory 230 and DPB 218 may be provided by the same memory device or separate memory devices. In various examples, video data memory 230 may be on-chip with, or off-chip with respect to, other components of video encoder 200 as illustrated.

In this disclosure, references to video data memory 230 are not to be construed as limited to memory internal to video encoder 200 unless specifically described as such, or memory external to video encoder 200 unless specifically described as such. It shouldn't be. Rather, reference to video data memory 230 should be understood as a reference memory that stores video data that video encoder 200 receives for encoding (e.g., video data for the current block to be encoded). Memory 106 of FIG. 1 may also provide temporary storage of outputs from various units of video encoder 200.

The various units in FIG. 6 are illustrated to aid understanding of the operations performed by video encoder 200. The units may be implemented as fixed function circuits, programmable circuits, or a combination thereof. Fixed function circuits refer to circuits that provide specific functionality and are preset for the operations that can be performed. Programmable circuits refer to circuits that can be programmed to perform various tasks and provide flexible functionality in the operations that may be performed. For example, programmable circuits may execute software or firmware that causes the programmable circuits to operate in a manner defined by instructions of the software or firmware. Fixed function circuits may execute software instructions (eg, to receive parameters or output parameters), but the types of operations that fixed function circuits perform are generally immutable. In some examples, one or more of the units may be separate circuit blocks (fixed function or programmable), and in some examples, one or more of the units may be integrated circuits.

Video encoder 200 may include arithmetic logic units (ALUs), elementary function units (EFUs), digital circuits, analog circuits, and/or programmable cores formed from programmable circuits. It may be possible. In examples where the operation of video encoder 200 is performed using software executed by programmable circuitry, memory 106 (FIG. 1) stores instructions in the software that video encoder 200 receives and executes (e.g. For example, object code), or other memory (not shown) within video encoder 200 may store such instructions.

Video data memory 230 is configured to store received video data. Video encoder 200 may retrieve an image of video data from video data memory 230 and provide the video data to residual generation unit 204 and mode selection unit 202. Video data in video data memory 230 may be raw video data to be encoded.

Mode selection unit 202 includes motion estimation unit 222, motion compensation unit 224, and intra prediction unit 226. Mode selection unit 202 may include additional functional units to perform video prediction according to different prediction modes. By way of example, mode selection unit 202 may be a palette unit, an intra block copy unit (which may be part of motion estimation unit 222 and/or motion compensation unit 224), an affine unit, a linear model (LM) unit, etc. It may also include .

Mode select unit 202 generally adjusts multiple encoding passes to test combinations of encoding parameters and resulting rate distortion values for those combinations. Encoding parameters may include partitioning of CTUs into CUs, prediction modes for CUs, transformation types for residual data of CUs, quantization parameters for residual data of CUs, etc. Mode select unit 202 may ultimately select a combination of encoding parameters that has better rate-distortion values than other tested combinations.

Video encoder 200 may partition a picture retrieved from video data memory 230 into a series of CTUs and encapsulate one or more CTUs within a slice. The mode selection unit 202 has the MTT structure and QTBT structure described above. The CTU of an image may be partitioned according to a tree structure such as a superblock structure or a quadtree structure. As described above, video encoder 200 may form one or more CUs from partitioning a CTU according to a tree structure. Such CUs may also be generally referred to as “video blocks” or “blocks.”

In general, mode select unit 202 also controls its components (e.g., motion estimation unit 222, motion compensation unit 224, and intra prediction unit 226) to select the current block (e.g. , generate a prediction block for the current CU (or, in HEVC, the overlapping portion of PU and TU). For inter prediction of the current block, motion estimation unit 222 performs a motion estimation unit 222 to identify one or more closely matching reference blocks in one or more reference pictures (one or more previously coded pictures stored in DPB 218). You can also perform a search. In particular, motion estimation unit 222 may determine potential reference blocks according to, for example, sum of absolute differences (SAD), sum of squared differences (SSD), mean absolute difference (MAD), mean squared differences (MSD), etc. We can also calculate a value indicating how similar this block is to the current block. Motion estimation unit 222 may perform these calculations generally using sample-by-sample differences between the reference block being considered and the current block. Motion estimation unit 222 may identify the reference block with the lowest value resulting from these calculations, which indicates the reference block that most closely matches the current block.

Motion estimation unit 222 may form one or more motion vectors (MVs) that define positions of reference blocks in reference pictures relative to the position of the current block in the current picture. Motion estimation unit 222 may then provide motion vectors to motion compensation unit 224. For example, for unidirectional inter prediction, motion estimation unit 222 may provide a single motion vector, while for bidirectional inter prediction, motion estimation unit 222 may provide two motion vectors. Motion compensation unit 224 may then use the motion vectors to generate a prediction block. For example, motion compensation unit 224 may use the motion vector to retrieve data of a reference block. As another example, if the motion vector has fractional sample precision, motion compensation unit 224 may interpolate the values for the prediction block according to one or more interpolation filters. Moreover, for two-way inter prediction, motion compensation unit 224 retrieves data for the two reference blocks identified by their respective motion vectors and combines the retrieved data, e.g., through sample-by-sample averaging or weighted averaging. You may.

When operating according to the AV1 video coding format, motion estimation unit 222 and motion compensation unit 224 may perform translational motion compensation, affine motion compensation, nested block motion compensation (OBMC), and/or complex intercompensation. - may be configured to encode coding blocks (e.g., both luma and chroma coding blocks) of video data using compound inter-intra prediction.

As another example, for intra prediction or intra prediction coding, intra prediction unit 226 may generate a prediction block from samples neighboring the current block. For example, for directional modes, intra prediction unit 226 typically generates a prediction block by mathematically combining the values of neighboring samples and populating these calculated values in a defined direction across the current block. You can also create As another example, for DC mode, intra-prediction unit 226 may calculate the average of neighboring samples for the current block and generate a prediction block to include this resulting average for each sample of the prediction block. there is.

When operating according to the AV1 video coding format, intra prediction unit 226 may perform directed intra prediction, undirectional intra prediction, recursive filter intra prediction, chroma-from-luma (CFL) prediction, intra block copy (IBC), and/or Alternatively, it may be configured to encode coding blocks (eg, both luma and chroma coding blocks) of video data using a color palette mode. Mode selection unit 202 may include additional functional units to perform video prediction according to different prediction modes.

Mode selection unit 202 provides the prediction block to residual generation unit 204. Residual generation unit 204 receives a raw, unencoded version of the current block from video data memory 230 and a prediction block from mode select unit 202. The 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 differences between sample values in a residual block to generate the residual block using residual differential pulse code modulation (RDPCM). In some examples, residual generation unit 204 may be formed using one or more subtractor circuits that perform binary subtraction.

In examples where mode select unit 202 partitions CUs into PUs, each PU may be associated with a luma prediction unit and corresponding chroma prediction units. Video encoder 200 and video decoder 300 may support PUs of various sizes. As indicated above, the size of a CU may refer to the size of a luma coding block of the CU, and the size of a PU may refer to the size of a luma prediction unit of the PU. Assuming the size of a particular CU is 2Nx2N, video encoder 200 supports PU sizes of 2Nx2N or NxN for intra prediction and symmetric PU sizes of 2Nx2N, 2NxN, Nx2N, NxN, or similar for inter prediction. You can also apply. Video encoder 200 and video decoder 300 may also support asymmetric partitioning for PU sizes of 2NxnU, 2NxnD, nLx2N, and nRx2N for inter prediction.

In examples where mode select unit 202 does not further partition the CU into PUs, each CU may be associated with a luma coding block and corresponding chroma coding blocks. As above, the size of the CU may refer to the size of the luma coding block of the CU. Video encoder 200 and video decoder 300 may support CU sizes of 2Nx2N, 2NxN, or Nx2N.

For other video coding techniques, such as intra block copy mode coding, affine mode coding, and linear model (LM) mode coding, as some examples, the mode selection unit 202 provides the information on the code being encoded, through the respective units associated with the coding technique. Generates a prediction block for the current block. In some examples, such as palette mode coding, mode select unit 202 may not generate a predictive block, but instead generate syntax elements that indicate how to reconstruct the block based on the selected palette. In such modes, mode select unit 202 may provide these syntax elements to entropy encoding unit 220 to be encoded.

As described above, residual generation unit 204 receives video data for the current block and the corresponding prediction block. Residual generation unit 204 then generates a residual block for the current block. To generate a residual block, residual generation unit 204 calculates sample-by-sample differences between the prediction block and the current block.

Transform processing unit 206 applies one or more transforms to the residual block to generate a block of transform coefficients (referred to herein as a “transform coefficient block”). Transform processing unit 206 may apply various transforms to the residual block to form a transform coefficient block. For example, transform processing unit 206 may apply a discrete cosine transform (DCT), a directional transform, a Karhunen-Loeve transform (KLT), or a conceptually similar transform to the residual block. In some examples, transform processing unit 206 may perform multiple transforms on the residual block, such as a first-order transform and a second-order transform, such as a rotation transform. In some examples, transform processing unit 206 does not apply transforms to the residual block.

When operating in accordance with AV1, transform processing unit 206 may apply one or more transforms to the residual block to generate a block of transform coefficients (referred to herein as a “transform coefficient block”). Transform processing unit 206 may apply various transforms to the residual block to form a transform coefficient block. For example, transform processing unit 206 may include a discrete cosine transform (DCT), an asymmetric discrete sine transform (ADST), an inverted ADST (e.g., inverted ADST), and a horizontal identity transform (IDTX). /vertical transformation combination can be applied. When using an identity transformation, the transformation is skipped in either the vertical or horizontal direction. In some examples, conversion processing may be skipped.

Quantization unit 208 may quantize the transform coefficients in a transform coefficient block to generate a quantized transform coefficient block. Quantization unit 208 may quantize the transform coefficients of the transform coefficient block according to a quantization parameter (QP) value associated with the current block. Video encoder 200 may adjust the degree of quantization applied to transform coefficient blocks associated with the current block by adjusting the QP value associated with the CU (e.g., via mode select unit 202). Quantization may introduce loss of information, and thus quantized transform coefficients may have lower precision than the original transform coefficients generated by transform processing unit 206.

Inverse quantization unit 210 and inverse transform processing unit 212 may apply inverse quantization and inverse transforms, respectively, to the quantized transform coefficient block to reconstruct a residual block from the transform coefficient block. Reconstruction unit 214 may generate a reconstructed block corresponding to the current block (potentially with some degree of distortion) based on the prediction block and the reconstructed residual block generated by mode selection unit 202. It may be possible. For example, reconstruction unit 214 may add samples of the reconstructed residual block to corresponding samples from the prediction block produced by mode select unit 202 to generate a reconstructed block.

Filter unit 216 may perform one or more filter operations on the reconstructed blocks. For example, filter unit 216 may perform deblocking operations to reduce blockiness artifacts along the edges of CUs. Operations of filter unit 216 may be skipped in some examples.

When operating in accordance with AV1, filter unit 216 may perform one or more filter operations on the reconstructed blocks. For example, filter unit 216 may perform deblocking operations to reduce blockiness artifacts along the edges of CUs. In other examples, filter unit 216 may apply a constrained directional enhancement filter (CDEF), which may be applied after deblocking and a series of non-separable nonlinear low-pass directional filters based on the estimated edge directions. May also include application. Filter unit 216 may also include a loop restoration filter applied after CDEF, a separable symmetric normalized Wiener filter, or a dual self-guided filter.

Video encoder 200 stores the reconstructed blocks in DPB 218. For example, in instances where the operations of filter unit 216 are not performed, reconstruction unit 214 may store the reconstructed blocks in DPB 218. In examples in which the operations of filter unit 216 are performed, filter unit 216 may store the filtered reconstructed blocks in DPB 218. Motion estimation unit 222 and motion compensation unit 224 retrieve a reference picture from DPB 218, formed from the reconstructed (and potentially filtered) blocks, and inter-process the blocks of subsequently encoded pictures. It can also be predicted. Additionally, intra prediction unit 226 may use the reconstructed blocks in DPB 218 of the current picture to intra predict other blocks in the current picture.

In general, entropy encoding unit 220 may entropy encode syntax elements received from other functional components of video encoder 200. For example, entropy encoding unit 220 may entropy encode quantized transform coefficient blocks from quantization unit 208. As another example, entropy encoding unit 220 may entropy encode prediction syntax elements (e.g., intra-mode information for intra-prediction or motion information for inter-prediction) from mode selection unit 202. there is. Entropy encoding unit 220 may perform one or more entropy encoding operations on syntax elements, another example of video data, to generate entropy encoded data. For example, entropy encoding unit 220 may include a context adaptive variable length coding (CAVLC) operation, a CABAC operation, a variable-to-variable (V2V) length coding operation, a syntax-based context adaptive binary arithmetic coding (SBAC) operation, A Probabilistic Interval Partitioning Entropy (PIPE) coding operation, an Exponential-Golomb encoding operation, or another type of entropy encoding operation may be performed on the data. In some examples, entropy encoding unit 220 may operate in a bypass mode in which syntax elements are not entropy encoded.

Video encoder 200 may output a bitstream containing entropy encoded syntax elements needed to reconstruct blocks of a picture or slice. In particular, entropy encoding unit 220 may output a bitstream.

According to AV1, entropy encoding unit 220 may be configured as a symbol-to-symbol adaptive multi-symbol arithmetic coder. A syntax element in AV1 contains an alphabet of N elements, and the context (eg, a probability model) contains a set of N probabilities. Entropy encoding unit 220 may store the probability as an n-bit (e.g., 15-bit) cumulative distribution function (CDF). Entropy encoding unit 220 may perform recursive scaling with an update factor based on the alphabet size to update the context.

The operations described above are explained in terms of blocks. Such description should be understood as operations for luma coding blocks and/or chroma coding blocks. As described above, in some examples, the luma coding block and chroma coding blocks are the luma and chroma components of a CU. In some examples, the luma coding block and chroma coding blocks are luma and chroma components of a PU.

In some examples, operations performed on a luma coding block do not need to be repeated for chroma coding blocks. As an example, the operations to identify the motion vector (MV) and reference picture for a luma coding block need not be repeated to identify the MV and reference picture for chroma blocks. Rather, the MV for the luma coding block may be scaled to determine the MV for the chroma blocks, and the reference picture may be the same. As another example, the intra prediction process may be the same for luma coding blocks and chroma coding blocks.

In accordance with the SEI technique discussed above, video encoder 200 includes a memory configured to store video data, and one or more processing units implemented in circuitry configured to receive an image and encode an image orientation message that includes a transform type syntax element. Represents an example of a device configured to encode video data comprising: wherein the transformation type syntax element indicates a transformation to be applied to the image, among a plurality of transformations. Video encoder 200 may be further configured to encode a quality metrics message including a quality metrics syntax element, where the quality metrics syntax element indicates a value of a quality metric associated with the picture.

FIG. 7 is a block diagram illustrating an example video decoder 300 that may perform the techniques of this disclosure. 7 is provided for illustrative purposes and is not limiting to the technology as broadly illustrated and described in this disclosure. For purposes of explanation, this disclosure describes a video decoder 300 according to the techniques of VVC (ITU-T H.266, under development), and HEVC (ITU-T H.265). However, the techniques of this disclosure may be performed by video coding devices configured with other video coding standards.

In the example of FIG. 7 , video decoder 300 includes coded picture buffer (CPB) memory 320, entropy decoding unit 302, prediction processing unit 304, inverse quantization unit 306, and inverse transform processing unit. 308, reconstruction unit 310, filter unit 312, and decoded picture buffer (DPB) 314. CBP 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. ) any or all of may be implemented in one or more processors or processing circuits. For example, units of video decoder 300 may be implemented as one or more circuits or logic elements as part of a hardware circuit, or as part of a processor, ASIC, or FPGA. Moreover, video decoder 300 may include additional or alternative processors or processing circuitry to perform these and other functions.

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

When operating in accordance with AV1, compensation unit 316 may use translational motion compensation, affine motion compensation, OBMC, and/or complex inter-intra prediction, as described above, to code blocks of video data (e.g., luma and Both chroma coding blocks) may be configured to decode. Intra prediction unit 318 uses directed intra prediction, non-directional intra prediction, recursive filter intra prediction, CFL, intra block copy (IBC), and/or color palette modes as described above to code blocks of video data (e.g. For example, both luma and chroma coding blocks) may be configured to decode.

CPB memory 320 may store video data, such as an encoded video bitstream, to be decoded by a component of video decoder 300. Video data stored in CPB memory 320 may be obtained, for example, from computer-readable medium 110 (FIG. 1). CPB memory 320 may include a CPB that stores encoded video data (e.g., syntax elements) from an encoded video bitstream. CPB memory 320 may also store video data other than syntactic elements of coded pictures, such as temporal data representing outputs from various units of video decoder 300. DPB 314 generally stores decoded pictures that video decoder 300 may output and/or use as reference video data when decoding subsequent data or pictures of the encoded video bitstream. CPB memory 320 and DPB 314 may be formed by any of a variety of memory devices, such as DRAM, including SDRAM, MRAM, RRAM, or other types of memory devices. CPB memory 320 and DPB 314 may be provided by the same memory device or separate memory devices. In various examples, CPB memory 320 may be on-chip with, or off-chip relative to, other components of video decoder 300.

Additionally or alternatively, in some examples, video decoder 300 may retrieve coded video data from memory 120 (Figure 1). That is, memory 120 may store data as discussed above with CPB memory 320. Likewise, memory 120 may store instructions to be executed by video decoder 300 when some or all of the functionality of video decoder 300 is implemented in software to be executed by the processing circuitry of video decoder 300. .

The various units shown in FIG. 7 are illustrated to aid understanding of the operations performed by video decoder 300. The units may be implemented as fixed function circuits, programmable circuits, or a combination thereof. Similar to Figure 6, fixed function circuits refer to circuits that provide specific functionality and are preset for the operations that can be performed. Programmable circuits refer to circuits that can be programmed to perform various tasks and provide flexible functionality in the operations that may be performed. For example, programmable circuits may execute software or firmware that causes the programmable circuits to operate in a manner defined by instructions of the software or firmware. Fixed function circuits may execute software instructions (eg, to receive parameters or output parameters), but the types of operations that fixed function circuits perform are generally immutable. In some examples, one or more of the units may be separate circuit blocks (fixed function or programmable), and in some examples, one or more of the units may be integrated circuits.

Video decoder 300 may include ALUs, EFUs, digital circuits, analog circuits, and/or programmable cores formed from programmable circuits. In examples where the operations of video decoder 300 are performed by software executing on programmable circuits, on-chip or off-chip memory may store instructions in the software that video decoder 300 receives and executes (e.g. , object code) can also be stored.

Entropy decoding unit 302 may receive encoded video data from CPB and entropy decode the video data to reproduce syntax elements. Prediction processing unit 304, inverse quantization unit 306, inverse transform processing unit 308, reconstruction unit 310, and filter unit 312 decode video data based on syntax elements extracted from the bitstream. You can also create .

In general, video decoder 300 reconstructs a picture on a block-by-block basis. Video decoder 300 may perform a reconstruction operation on each block individually (where the block currently being reconstructed, i.e., being decoded, may be referred to as a “current block”).

Entropy decoding unit 302 may entropy decode syntax elements defining quantized transform coefficients of a quantized transform coefficient block, as well as transform information, such as quantization parameters (QP) and/or transform mode indication(s). Inverse quantization unit 306 may use the QP associated with the quantized transform coefficient block to determine the degree of quantization and likewise the degree of inverse quantization that inverse quantization unit 306 will apply. Inverse quantization unit 306 may perform a bitwise left-shift operation, for example, to inverse quantize quantized transform coefficients. Inverse quantization unit 306 may thereby form a transform coefficient block containing transform coefficients.

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

Prediction processing unit 304 also generates a prediction block according to prediction information syntax elements that have been entropy decoded by entropy decoding unit 302. For example, if the prediction information syntax elements indicate that the current block is inter predicted, motion compensation unit 316 may generate a prediction block. In this case, the prediction information syntax elements may indicate a motion vector that identifies the location of the reference block in the reference picture relative to the location of the current block in the current picture, as well as the reference picture in DPB 314 from which to retrieve the reference block. It may be possible. Motion compensation unit 316 may perform inter-side processes generally in a manner substantially similar to that described for motion compensation unit 224 (Figure 6).

As another example, if the prediction information syntax element indicates that the current block is intra predicted, intra prediction unit 318 may generate the prediction block according to the intra prediction mode indicated by the prediction information syntax element. Again, intra prediction unit 318 may perform the intra prediction process generally in a manner substantially similar to that described for intra prediction unit 226 (Figure 6). Intra prediction unit 318 may retrieve data of neighboring samples for the current block from DPB 314.

Reconstruction unit 310 may reconstruct the current block using the prediction block and the residual block. For example, reconstruction unit 310 may add samples of the residual block to corresponding samples of the prediction block to reconstruct the current block.

Filter unit 312 may perform one or more filter operations on the reconstructed blocks. For example, filter unit 312 may perform deblocking operations to reduce blockiness artifacts along the edges of reconstructed blocks. The operations of filter unit 312 are not necessarily performed in all examples.

Video decoder 300 may store the reconstructed blocks in DPB 314. For example, in instances where the operations of filter unit 312 are not performed, reconstruction unit 310 may store the reconstructed blocks in DPB 314. In examples in which the operations of filter unit 312 are performed, filter unit 312 may store the filtered reconstructed blocks in DPB 314. As described above, DPB 314 may provide prediction processing unit 304 with reference information, such as samples of the current picture for intra-prediction and previously decoded pictures for subsequent motion compensation. Moreover, video decoder 300 may output decoded pictures (e.g., decoded video) from DPB 314 for subsequent presentation on a display device, such as display device 118 of FIG. 1. there is.

In accordance with the SEI technique discussed above, video decoder 300 includes a memory configured to store video data, and one or more processing units implemented in circuitry configured to receive an image and decode an image orientation message that includes a transform type syntax element. Represents an example of a device configured to decode video data comprising, where the transform type syntax element indicates a transform to be applied to the picture, among a plurality of transforms. Video decoder 300 may be further configured to decode a quality metrics message that includes a quality metrics syntax element, where the quality metrics syntax element indicates a value of a quality metric associated with the picture.

8 is a flowchart illustrating an example method for encoding a current block according to the techniques of this disclosure. The current block may include the current CU. Although described with respect to video encoder 200 ( FIGS. 1 and 6 ), it should be understood that other devices may be configured to perform methods similar to FIG. 8 .

In this example, video encoder 200 initially predicts the current block (350). For example, video encoder 200 may form a prediction block for the current block. Video encoder 200 may then calculate a residual block for the current block (352). To calculate the residual block, video encoder 200 may calculate the difference between the original unencoded block and the prediction block for the current block. Video encoder 200 may then transform the residual block and quantize the transform coefficients of the residual block (354). Next, video encoder 200 may scan the quantized transform coefficients of the residual block (356). During, or following a scan, video encoder 200 may entropy encode the transform coefficients (358). For example, video encoder 200 may encode transform coefficients using CAVLC or CABAC. Video encoder 200 may then output the block's entropy encoded data (360).

9 is a flowchart illustrating an example method for decoding a current block of video data according to the techniques of this disclosure. The current block may include the current CU. Although described with respect to video decoder 300 ( FIGS. 1 and 7 ), it should be understood that other devices may be configured to perform methods similar to FIG. 9 .

Video decoder 300 may receive entropy encoded data for a current block, such as entropy encoded prediction information and entropy encoded data for transform coefficients of a residual block corresponding to the current block (370). Video decoder 300 may entropy decode the entropy encoded data to determine prediction information for the current block and reproduce the transform coefficients of the residual block (372). Video decoder 300 may predict the current block, e.g., using an intra- or inter-prediction mode, as indicated by the prediction information for the current block, to calculate a prediction block for the current block (374 ). Video decoder 300 may inverse scan the reproduced transform coefficients to generate a block of quantized transform coefficients (376). Video decoder 300 may then inverse quantize the transform coefficients and apply an inverse transform to the transform coefficients to generate a residual block (378). Video decoder 300 may ultimately decode the current block by combining the prediction block and the residual block (380).

Other example aspects of the techniques and devices of the present disclosure are described below.

Aspect 1A - A method of processing video data, the method comprising: receiving an image; and coding an image orientation supplemental enhancement information (SEI) message that includes one or more of a cancel flag, a persistence flag, a component image matching flag, or a transformation type syntax element, wherein the transformation type syntax element specifies a rotation to be applied to the image. or a method of processing video data, indicating one or more of mirroring.

Aspect 2A - The method of aspect 1A, wherein coding includes decoding, and the method further comprises processing the image according to the image orientation SEI message.

Aspect 3A - The method of Aspect 1A or Aspect 2A, wherein the picture orientation message comprises a picture orientation supplemental enhancement information (SEI) message.

Aspect 4A - The method of aspect 1A or aspect 2A, wherein the picture orientation message comprises an picture orientation open bitstream unit (OBU).

Aspect 5A - The method of claim 1A, wherein coding comprises encoding.

Aspect 6A - A method of processing video data, the method comprising: receiving an image; and coding a picture quality metrics supplemental enhancement information (SEI) message comprising one or more syntax elements indicating quality metrics of the picture.

Aspect 7A - The method of aspect 6A, wherein coding includes decoding, and the method further comprises processing the image according to the image quality metrics SEI message.

Aspect 8A - The method of either Aspect 6A or Aspect 7A, wherein the image orientation message includes an image quality metrics supplemental enhancement information (SEI) message.

Aspect 9A - The method of any of Aspects 6A-8A, wherein the picture quality metrics message includes one or more syntax elements representing quality metrics of one or more subpictures or regions of interest in the picture associated with the picture quality metrics message. .

Aspect 10A - The method of aspect 9A, wherein the one or more syntax elements represent high dynamic range (HDR) or quality metrics of 360 video content.

Aspect 11A - The method of any of Aspects 6A-10A, wherein coding comprises encoding.

Aspect 12A—Any combination of the methods of Aspects 1A-10A.

Aspect 13A - A device for processing video data, wherein the device includes one or more means for performing the method of any of aspects 1A-12A.

Aspect 14A - The device of aspect 13A, wherein the one or more means comprises one or more processors implemented in circuitry.

Aspect 15A - The device of any of Aspects 13A and 14A, further comprising a memory for storing video data.

Aspect 16A - The device of any of aspects 13A-15A, further comprising a display configured to display decoded video data.

Aspect 17A - The device of any of Aspects 13A-16A, wherein the device comprises one or more of a camera, a computer, a mobile device, a broadcast receiver device, or a set top box.

Aspect 18A - The device of any of aspects 13A-17A, wherein the device comprises a video decoder.

Aspect 19A - The device of any of Aspects 13A-18A, wherein the device comprises a video encoder.

Aspect 20A - A computer-readable storage medium having instructions stored thereon that, when executed, cause one or more processors to perform the method of any of aspects 1A-12A.

Aspect 1B - A method of processing video data, the method comprising: receiving an image; and coding a quality metrics message including a quality metrics syntax element, wherein the quality metrics syntax element represents a value of a quality metric associated with the image.

Aspect 2B - The method of Aspect 1B, further comprising coding a quality metric type syntax element in the quality metrics message, wherein the quality metric type syntax element is one of a quality metric type among the plurality of quality metric types indicated by the quality metric syntax element. Indicates the type and method of processing video data.

Aspect 3B - The method of aspect 2B, wherein the plurality of quality metrics types include peak signal-to-noise ratio (PSNR).

Aspect 4B - The method of aspect 2B, wherein the plurality of quality metrics types are peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), multiscale structural similarity index (MS-SSIM), video quality metric (VQM), weighted. A method of processing video data, comprising two or more of PSNR (wPSNR), weighted to spherically uniform PSNR (WS-PSNR), sequence PSNR, sequence wPSNR, or sequence WS-PSNR.

Aspect 5B - The method of aspect 2B, wherein the quality metric syntax element represents a value of the quality metric indicated by the quality metric type syntax element.

Aspect 6B - The method of aspect 1B, further comprising coding a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element is a second quality metric related to a subpicture of the picture. 2 A method of processing video data that represents a value.

Aspect 7B - The method of aspect 1B, further comprising coding a second quality metrics message comprising a second quality metric syntax element, wherein the second quality metric syntax element is a second quality metric related to a region of interest in the image. 2 A method of processing video data that represents a value.

Aspect 8B - The method of aspect 1B, wherein coding includes decoding and the method further comprises applying a post-processing technique to the image according to the value of the quality metric to form a processed image; and displaying the processed image.

Aspect 9B - The method of aspect 1B, wherein the quality metrics message includes a quality metrics supplemental enhancement information (SEI) message.

Aspect 10B - The method of aspect 1B, wherein the quality metrics message includes a quality metrics open bitstream unit (OBU).

Aspect 11B - An apparatus configured to process video data, comprising: a memory configured to store an image; and one or more processors implemented in circuitry and in communication with the memory, wherein the one or more processors receive the image; An apparatus configured to process video data, configured to code a quality metrics message comprising a quality metrics syntax element, wherein the quality metrics syntax element represents a value of a quality metric associated with the image.

Aspect 12B - The method of Aspect 11B, wherein the one or more processors further code a quality metrics type syntax element in the quality metrics message, wherein the quality metrics type syntax element selects a quality metrics type from among the plurality of quality metrics types indicated by the quality metrics syntax element. A device configured to process video data, configured to indicate a type of metric.

Aspect 13B - The apparatus of aspect 12B, wherein the plurality of quality metrics types include peak signal-to-noise ratio (PSNR).

Aspect 14B - The method of aspect 12B, wherein the plurality of quality metrics types include Peak Signal to Noise Ratio (PSNR), Structural Similarity Index (SSIM), Multiscale Structural Similarity Index (MS-SSIM), Video Quality Metric (VQM), Weighted An apparatus configured to process video data, comprising two or more of PSNR (wPSNR), weighted to spherical uniform PSNR (WS-PSNR), sequence PSNR, sequence wPSNR, or sequence WS-PSNR.

Aspect 15B - The apparatus of aspect 12B, wherein the quality metric syntax element represents a value of the quality metric indicated by the quality metric type syntax element.

Aspect 16B - The method of aspect 11B, wherein the one or more processors are further configured to code a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element is a second quality metrics message related to a subpicture of the picture. An apparatus configured to process video data, the device representing a second value of a quality metric.

Aspect 17B - The method of aspect 11B, wherein the one or more processors are further configured to code a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element is configured to include a second quality metrics message related to a region of interest in the image. An apparatus configured to process video data, the device representing a second value of a quality metric.

Aspect 18B - The apparatus of aspect 11B, wherein an apparatus is configured to decode a quality metrics message, wherein the one or more processors apply a post-processing technique to the image according to the value of the quality metric to form a further processed image; A device configured to process video data, configured to display processed images.

Aspect 19B - The apparatus of aspect 11B, wherein the quality metrics message includes a quality metrics supplemental enhancement information (SEI) message.

Aspect 20B - The apparatus of aspect 11B, wherein the quality metrics message includes a quality metrics open bitstream unit (OBU).

Aspect 21B - An apparatus configured to process video data, comprising: means for receiving an image; and means for coding a quality metrics message comprising a quality metrics syntax element, wherein the quality metrics syntax element represents a value of a quality metric associated with the image.

Aspect 22B - The method of aspect 21B, further comprising means for coding a quality metric type syntax element in the quality metrics message, wherein the quality metric type syntax element is one of a quality metric type, from among the plurality of quality metric types indicated by the quality metric syntax element. A device configured to process video data, representing a type.

Aspect 23B - The apparatus of aspect 22B, wherein the plurality of quality metrics types include peak signal-to-noise ratio (PSNR).

Aspect 24B - The method of aspect 22B, wherein the plurality of quality metrics types include peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), multiscale structural similarity index (MS-SSIM), video quality metric (VQM), weighted. An apparatus configured to process video data, comprising two or more of PSNR (wPSNR), weighted to spherical uniform PSNR (WS-PSNR), sequence PSNR, sequence wPSNR, or sequence WS-PSNR.

Aspect 25B - The apparatus of aspect 22B, wherein the quality metric syntax element represents a value of the quality metric indicated by the quality metric type syntax element.

Aspect 26B - The method of aspect 21B, further comprising means for coding a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element is a second quality metric related to a subpicture of the picture. 2 A device configured to process video data, representing a value.

Aspect 27B - The method of aspect 21B, further comprising means for coding a second quality metrics message comprising a second quality metric syntax element, wherein the second quality metric syntax element is a second quality metric related to a region of interest in the image. 2 A device configured to process video data, representing a value.

Aspect 28B - The method of aspect 21B, wherein the means for coding includes means for decoding, and the apparatus includes means for applying a post-processing technique to the image according to the value of the quality metric to form a processed image; and means for displaying the processed image.

Aspect 29B - The apparatus of aspect 21B, wherein the quality metrics message includes a quality metrics supplemental enhancement information (SEI) message.

Aspect 30B - The apparatus of aspect 21B, wherein the quality metrics message includes a quality metrics open bitstream unit (OBU).

Aspect 31B - A non-transitory computer-readable storage medium storing instructions that, when executed, cause one or more processors of a device configured to process video data to receive an image, comprising: a quality metric comprising a quality metric syntax element; A non-transitory computer-readable storage medium that allows coding a message, wherein the quality metric syntax element represents the value of a quality metric associated with the image.

Aspect 32B - The method of aspect 31B, wherein the instructions further cause the one or more processors to code a quality metrics type syntax element in a quality metrics message, wherein the quality metrics type syntax element is configured to include a plurality of quality metrics indicated by the quality metrics syntax element. Among the types, non-transitory computer-readable storage media that represents a type of quality metric.

Aspect 33B - The non-transitory computer readable storage medium of aspect 32B, wherein the plurality of quality metrics types include peak signal to noise ratio (PSNR).

Aspect 34B - The method of aspect 32, wherein the plurality of quality metrics types include Peak Signal to Noise Ratio (PSNR), Structural Similarity Index (SSIM), Multiscale Structural Similarity Index (MS-SSIM), Video Quality Metric (VQM), Weighted A non-transitory computer-readable storage medium comprising two or more of PSNR (wPSNR), weighted to spherically uniform PSNR (WS-PSNR), sequence PSNR, sequence wPSNR, or sequence WS-PSNR.

Aspect 35B - The non-transitory computer-readable storage medium of aspect 32B, wherein the quality metric syntax element represents a value of the quality metric indicated by the quality metric type syntax element.

Aspect 36B - The method of aspect 31B, wherein the instructions further cause the one or more processors to code a second quality metrics message including a second quality metrics syntax element, wherein the second quality metrics syntax element is associated with a subpicture of the picture. A non-transitory computer-readable storage medium representing a second value of an associated second quality metric.

Aspect 37B - The method of aspect 31B, wherein the instructions further cause the one or more processors to code a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element is to be associated with a region of interest in the image. A non-transitory computer-readable storage medium representing a second value of an associated second quality metric.

Aspects 38B - The device of aspect 31B, wherein the device is configured to decode a quality metrics message, wherein the instructions further cause the one or more processors to perform a post-processing technique on the image according to the value of the quality metric to form a processed image. apply; A non-transitory computer-readable storage medium that allows display of processed images.

Aspect 39B - The non-transitory computer-readable storage medium of aspect 31B, wherein the quality metrics message comprises a quality metrics supplemental enhancement information (SEI) message.

Aspect 40B - The non-transitory computer-readable storage medium of aspect 31B, wherein the quality metrics message comprises a quality metrics open bitstream unit (OBU).

Aspect 1C - A method of processing video data, comprising: receiving an image; and coding a quality metrics message including a quality metrics syntax element, wherein the quality metrics syntax element represents a value of a quality metric associated with the image.

Aspect 2C - The method of Aspect 1C, further comprising coding a quality metric type syntax element in the quality metrics message, wherein the quality metric type syntax element is one of a quality metric type among the plurality of quality metric types indicated by the quality metric syntax element. Indicates the type and method of processing video data.

Aspect 3C - The method of aspect 2C, wherein the plurality of quality metrics types include peak signal-to-noise ratio (PSNR).

Aspect 4C - The method of aspect 2C, wherein the plurality of quality metrics types are Peak Signal to Noise Ratio (PSNR), Structural Similarity Index (SSIM), Multiscale Structural Similarity Index (MS-SSIM), Video Quality Metric (VQM), Weighted A method of processing video data, comprising two or more of PSNR (wPSNR), weighted to spherically uniform PSNR (WS-PSNR), sequence PSNR, sequence wPSNR, or sequence WS-PSNR.

Aspect 5C - The method of any of Aspects 2C-4C, wherein the quality metric syntax element represents a value of the quality metric indicated by the quality metric type syntax element.

Aspect 6C - The method of any of Aspects 1C-5C, further comprising coding a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element is a second quality metrics message related to a subpicture of the picture. A method of processing video data, indicating a second value of a quality metric.

Aspect 7C - The method of any of Aspects 1C-5C, further comprising coding a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element is a second quality metrics message related to a region of interest in the image. A method of processing video data, indicating a second value of a quality metric.

Aspect 8C - The method of any of Aspects 1C-7C, wherein coding includes decoding and the method further comprises applying a post-processing technique to the image according to the value of the quality metric to form a processed image; and displaying the processed image.

Aspect 9C - The method of any of Aspects 1C-8C, wherein the quality metrics message includes a quality metrics supplemental enhancement information (SEI) message.

Aspect 10C - The method of any of Aspects 1C-8C, wherein the quality metrics message includes a quality metrics open bitstream unit (OBU).

Aspect 11C - An apparatus configured to process video data, comprising: a memory configured to store an image; and one or more processors implemented in circuitry and in communication with the memory, wherein the one or more processors receive the image; An apparatus configured to process video data, configured to code a quality metrics message comprising a quality metrics syntax element, wherein the quality metrics syntax element represents a value of a quality metric associated with the image.

Aspect 12C - The method of aspect 11C, wherein the one or more processors are further configured to code a quality metrics type syntax element in the quality metrics message, wherein the quality metrics type syntax element is one of the plurality of quality metrics types indicated by the quality metrics syntax element. , a device configured to process video data, representing a type of quality metric.

Aspect 13C - The apparatus of aspect 12C, wherein the plurality of quality metrics types include peak signal-to-noise ratio (PSNR).

Aspect 14C - The method of aspect 12C, wherein the plurality of quality metrics types include peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), multiscale structural similarity index (MS-SSIM), video quality metric (VQM), weighted. An apparatus configured to process video data, comprising two or more of PSNR (wPSNR), weighted to spherical uniform PSNR (WS-PSNR), sequence PSNR, sequence wPSNR, or sequence WS-PSNR.

Aspect 15C - The apparatus of any of Aspects 12C-14C, wherein the quality metric syntax element represents a value of the quality metric indicated by the quality metric type syntax element.

Aspect 16C - The method of any of Aspects 11C-15C, wherein the one or more processors are further configured to code a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element is a subpicture of the picture. An apparatus configured to process video data, wherein the device indicates a second value of a second quality metric related to .

Aspect 17C - The method of any of Aspects 11C-15C, wherein the one or more processors are further configured to code a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element is configured to include a region of interest in the image. An apparatus configured to process video data, wherein the device indicates a second value of a second quality metric related to .

Aspects 18C - The apparatus of any of aspects 11C-17C, wherein an apparatus is configured to decode a quality metrics message, wherein the one or more processors further perform post-processing techniques on the image according to the values of the quality metrics to form a processed image. apply; A device configured to process video data, configured to display processed images.

Aspect 19C - The apparatus of any of Aspects 11C-18C, wherein the quality metrics message includes a quality metrics supplemental enhancement information (SEI) message.

Aspect 20C - The apparatus of any of aspects 11C-18C, wherein the quality metrics message includes a quality metrics open bitstream unit (OBU).

Aspect 21C - An apparatus configured to process video data, comprising: means for receiving an image; and means for coding a quality metrics message comprising a quality metrics syntax element, wherein the quality metrics syntax element represents a value of a quality metric associated with the image.

Aspect 22C - The method of aspect 21C, further comprising means for coding a quality metric type syntax element in the quality metrics message, wherein the quality metric type syntax element is one of a quality metric type, from among the plurality of quality metric types indicated by the quality metric syntax element. A device configured to process video data, representing a type.

Aspect 23C - The apparatus of aspect 22C, wherein the plurality of quality metrics types include peak signal-to-noise ratio (PSNR).

Aspect 24C - The method of aspect 22C, wherein the plurality of quality metrics types include Peak Signal to Noise Ratio (PSNR), Structural Similarity Index (SSIM), Multiscale Structural Similarity Index (MS-SSIM), Video Quality Metric (VQM), Weighted An apparatus configured to process video data, comprising two or more of PSNR (wPSNR), weighted to spherical uniform PSNR (WS-PSNR), sequence PSNR, sequence wPSNR, or sequence WS-PSNR.

Aspect 25C - The apparatus of any of Aspects 22C-24C, wherein the quality metric syntax element represents a value of the quality metric indicated by the quality metric type syntax element.

Aspect 26C - The method of any of Aspects 21C-25C, further comprising means for coding a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element is a second quality metrics message associated with a subpicture of the picture. An apparatus configured to process video data, the device representing a second value of a quality metric.

Aspect 27C - The method of any of Aspects 21C-25C, further comprising means for coding a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element is a second quality metrics message related to a region of interest in the image. An apparatus configured to process video data, the device representing a second value of a quality metric.

Aspect 28C - The method of any of Aspects 21C-27C, wherein the means for coding comprises means for decoding, and the apparatus comprises means for applying a post-processing technique to the image according to the value of the quality metric to form a processed image; and means for displaying the processed image.

Aspect 29C - The apparatus of any of Aspects 21C-28C, wherein the quality metrics message includes a quality metrics supplemental enhancement information (SEI) message.

Aspect 30C - The apparatus of any of aspects 21C-28C, wherein the quality metrics message includes a quality metrics open bitstream unit (OBU).

Aspect 31C - A non-transitory computer-readable medium storing instructions that, when executed, cause one or more processors of a device configured to process video data to: receive an image and: a quality metrics message comprising a quality metrics syntax element; wherein the quality metric syntax element represents a value of a quality metric associated with the image.

Aspects 32C - The method of aspect 31C, wherein the instructions further cause the one or more processors to code a quality metrics type syntax element in a quality metrics message, wherein the quality metrics type syntax element is configured to include a plurality of qualities indicated by the quality metrics syntax element. Among the types of metrics, a non-transitory computer-readable medium representing a type of quality metric.

Aspect 33C - The non-transitory computer-readable medium of aspect 32C, wherein the plurality of quality metrics types include peak signal-to-noise ratio (PSNR).

Aspect 34C - The method of aspect 32, wherein the plurality of quality metrics types are Peak Signal to Noise Ratio (PSNR), Structural Similarity Index (SSIM), Multiscale Structural Similarity Index (MS-SSIM), Video Quality Metric (VQM), Weighted A non-transitory computer-readable medium comprising two or more of PSNR (wPSNR), weighted to spherically uniform PSNR (WS-PSNR), sequence PSNR, sequence wPSNR, or sequence WS-PSNR.

Aspect 35C - The non-transitory computer-readable medium of aspects 32C-34C, wherein the quality metric syntax element represents a value of the quality metric indicated by the quality metric type syntax element.

Aspect 36C - The method of aspects 31C-35C, wherein the instructions further cause the one or more processors to code a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element is a sub-category of the image. A non-transitory computer-readable medium representing a second value of a second quality metric related to an image.

Aspects 37C - The methods of aspects 31C-35C, wherein the instructions further cause the one or more processors to code a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element is configured to be of interest to the image. A non-transitory computer-readable medium representing a second value of a second quality metric related to a region.

Aspects 38C - The devices of aspects 31C-37C, wherein a device is configured to decode a quality metrics message, wherein the instructions further cause the one or more processors to post-process the image according to the value of the quality metric to form a processed image. apply techniques; A non-transitory computer-readable medium that allows display of processed images.

Aspects 39C - The non-transitory computer-readable medium of aspects 31C-38C, wherein the quality metrics message includes a quality metrics supplemental enhancement information (SEI) message.

Aspects 40C - The non-transitory computer-readable medium of aspects 31C-38C, wherein the quality metrics message includes a quality metrics open bitstream unit (OBU).

Depending on the example, certain acts or events of any of the techniques described herein may be performed in a different sequence, may be added, may be merged, or may be omitted altogether (e.g., all of the described acts may be omitted). It should be recognized that events or events are not required for implementation of the technique. Moreover, in certain examples, acts or events may be performed simultaneously, for example, through multi-threaded processing, interrupt processing, or multiple processors, rather than sequentially.

In one or more examples, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media refers to a type of medium, such as communication media or data storage media, including any medium that facilitates transfer of a computer program from one place to another according to a communication protocol, for example. It may also include a computer-readable storage medium. In this manner, computer-readable media may generally correspond to (1) a tangible computer-readable storage medium, or (2) a communication medium, such as a signal or carrier wave. A data storage medium may be any available medium that can be accessed by one or more computers or one or more processors to retrieve instructions, code and/or data structures for implementation of the techniques described in this disclosure. there is. A computer program product may include computer-readable media.

By way of non-limiting example, such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, flash memory, or the desired program in the form of instructions or data structures. It may include any other medium that can be used to store code and that can be accessed by a computer. Any connection is also properly termed a computer-readable medium. For example, instructions may be sent to a website, server, or other remote location using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves. When transmitted from a source, coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio waves, and microwaves are included within 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 instead refer to non-transitory, tangible storage media. Disk and disc as used herein include compact disk (CD), laser disk, optical disk, digital versatile disk (DVD), floppy disk and Blu-ray disk, where disk ( A disk usually reproduces data magnetically, but a disc reproduces data optically using a laser. Combinations of the above should also be included within the scope of computer-readable media.

Instructions may 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. Accordingly, the terms “processor” and “processing circuitry,” as used herein, may refer to any of the foregoing structures or any other structure suitable for implementation of the techniques described herein. Additionally, in some aspects, the functionality described herein may be provided within dedicated hardware and/or software modules configured for encoding and decoding, or may be integrated in a combined codec. Additionally, the technology may be fully implemented in one or more circuits or logic elements.

The technology of this disclosure may be implemented in a wide variety of devices or apparatuses, including a wireless handset, an integrated circuit (IC) or set of ICs (e.g., a chipset). Various components, modules, or units are described in this disclosure to highlight functional aspects of devices configured to perform the disclosed technology, but do not necessarily require implementation by different hardware units. Rather, as described above, the various units may be combined in a codec hardware unit or provided by a set of interoperable hardware units, including one or more processors as described above, together with suitable software and/or firmware. It may be possible.

Various examples have been described. These and other examples are within the scope of the following claims.

Claims (40)

A method of processing video data, comprising:
Receiving an image; and
Steps for coding a quality metrics message containing quality metrics syntax elements.
wherein the quality metric syntax element represents a value of a quality metric associated with the image. According to claim 1,
Further comprising coding a quality metric type syntax element in the quality metrics message, wherein the quality metric type syntax element indicates a type of quality metric indicated by the quality metric syntax element, among a plurality of quality metrics types. How to process video data. According to claim 2,
The method of processing video data, wherein the plurality of quality metrics types include peak signal-to-noise ratio (PSNR). According to claim 2,
The plurality of quality metrics types include peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), multiscale structural similarity index (MS-SSIM), video quality metric (VQM), weighted PSNR (wPSNR), and weighted-to-spherical. A method of processing video data, comprising two or more of uniform PSNR (WS-PSNR), sequence PSNR, sequence wPSNR, or sequence WS-PSNR. According to claim 2,
wherein the quality metric syntax element represents a value of the quality metric indicated by the quality metric type syntax element. According to claim 1,
further comprising coding a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element represents a second value of a second quality metric related to a subpicture of the picture. How to process data. According to claim 1,
The video further comprising coding a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element represents a second value of a second quality metric related to a region of interest in the image. How to process data. According to claim 1,
Coding includes decoding, and the method
applying a post-processing technique to the image according to the value of the quality metric to form a processed image; and
A method of processing video data, further comprising displaying the processed image. According to claim 1,
The method of processing video data, wherein the quality metrics message includes a quality metrics supplemental enhancement information (SEI) message. According to claim 1,
The method of processing video data, wherein the quality metrics message includes a quality metrics open bitstream unit (OBU). A device configured to process video data, comprising:
a memory configured to store images; and
comprising one or more processors implemented in circuitry and in communication with the memory,
The one or more processors
receive the image;
An apparatus configured to process video data, wherein the apparatus is configured to code a quality metrics message comprising a quality metrics syntax element, wherein the quality metrics syntax element represents a value of a quality metric associated with the picture. According to claim 11,
The one or more processors are additionally
configured to code a quality metric type syntax element in the quality metrics message, wherein the quality metric type syntax element indicates a type of quality metric indicated by the quality metric syntax element, among a plurality of quality metric types. A device configured to process. According to claim 12,
wherein the plurality of quality metrics types include peak signal-to-noise ratio (PSNR). According to claim 12,
The plurality of quality metrics types include peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), multiscale structural similarity index (MS-SSIM), video quality metric (VQM), weighted PSNR (wPSNR), and weighted-to-spherical. A device configured to process video data, comprising two or more of uniform PSNR (WS-PSNR), sequence PSNR, sequence wPSNR, or sequence WS-PSNR. According to claim 12,
wherein the quality metric syntax element represents a value of the quality metric indicated by the quality metric type syntax element. According to claim 11,
The one or more processors are additionally
Processing video data, configured to code a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element represents a second value of a second quality metric related to a subpicture of the picture. A device configured to do so. According to claim 11,
The one or more processors are additionally
Processing video data, configured to code a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element represents a second value of a second quality metric related to a region of interest in the image. A device configured to do so. According to claim 11,
The device is configured to decode the quality metrics message, and the one or more processors further
apply a post-processing technique to the image according to the value of the quality metric to form a processed image;
An apparatus configured to process video data, and configured to display the processed image. According to claim 11,
The apparatus configured to process video data, wherein the quality metrics message includes a quality metrics supplemental enhancement information (SEI) message. According to claim 11,
wherein the quality metrics message includes a quality metrics open bitstream unit (OBU). A device configured to process video data, comprising:
means for receiving images; and
A means of coding a quality metrics message containing quality metrics syntax elements.
and wherein the quality metric syntax element represents a value of a quality metric associated with the image. According to claim 21,
further comprising means for coding a quality metric type syntax element in the quality metrics message, wherein the quality metric type syntax element indicates a type of quality metric indicated by the quality metric syntax element, among a plurality of quality metric types, A device configured to process video data. According to claim 22,
wherein the plurality of quality metrics types include peak signal-to-noise ratio (PSNR). According to claim 22,
The plurality of quality metrics types include peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), multiscale structural similarity index (MS-SSIM), video quality metric (VQM), weighted PSNR (wPSNR), and weighted-to-spherical. A device configured to process video data, comprising two or more of uniform PSNR (WS-PSNR), sequence PSNR, sequence wPSNR, or sequence WS-PSNR. According to claim 22,
wherein the quality metric syntax element represents a value of the quality metric indicated by the quality metric type syntax element. According to claim 21,
and means for coding a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element represents a second value of a second quality metric associated with a subpicture of the picture. A device configured to process data. According to claim 21,
and means for coding a second quality metrics message comprising a second quality metrics syntax element, wherein the second quality metrics syntax element represents a second value of a second quality metric related to a region of interest in the image. A device configured to process data. According to claim 21,
The means for coding comprises means for decoding, and the device
means for applying a post-processing technique to the image according to the value of the quality metric to form a processed image; and
Means for displaying the processed image
A device configured to process video data, further comprising: According to claim 21,
The apparatus configured to process video data, wherein the quality metrics message includes a quality metrics supplemental enhancement information (SEI) message. According to claim 21,
wherein the quality metrics message includes a quality metrics open bitstream unit (OBU). A non-transitory computer-readable storage medium storing instructions, comprising:
When executed, the instructions cause one or more processors of a device configured to process video data to:
Receive the image and:
A non-transitory computer-readable storage medium that allows coding a quality metrics message comprising a quality metrics syntax element, wherein the quality metrics syntax element represents a value of a quality metric associated with the image. According to claim 31,
The instructions also cause the one or more processors to
Coding the quality metrics message with a quality metric type syntax element, wherein the quality metric type syntax element indicates a type of quality metric indicated by the quality metric syntax element, from among a plurality of quality metric types. Available storage media. According to claim 32,
The plurality of quality metrics types include peak signal-to-noise ratio (PSNR). According to claim 32,
The plurality of quality metrics types include peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), multiscale structural similarity index (MS-SSIM), video quality metric (VQM), weighted PSNR (wPSNR), and weighted-to-spherical. A non-transitory computer-readable storage medium comprising two or more of uniform PSNR (WS-PSNR), sequence PSNR, sequence wPSNR, or sequence WS-PSNR. According to claim 32,
wherein the quality metric syntax element represents a value of the quality metric indicated by the quality metric type syntax element. According to claim 31,
The instructions also cause the one or more processors to
coding a second quality metrics message comprising a second quality metrics syntax element, the second quality metrics syntax element representing a second value of a second quality metric associated with a subpicture of the picture. storage media. According to claim 31,
The instructions also cause the one or more processors to
coding a second quality metrics message comprising a second quality metrics syntax element, the second quality metrics syntax element representing a second value of a second quality metric related to a region of interest in the image. storage media. According to claim 31,
The device is configured to decode the quality metrics message, and the instructions also cause the one or more processors to
apply a post-processing technique to the image according to the value of the quality metric to form a processed image;
A non-transitory computer-readable storage medium for displaying the processed image. According to claim 31,
The quality metrics message includes a quality metrics supplemental enhancement information (SEI) message. According to claim 31,
The quality metrics message includes a quality metrics open bitstream unit (OBU).

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