Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/70—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals characterised by syntax aspects related to video coding, e.g. related to compression standards
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
  • H04N19/134—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or criterion affecting or controlling the adaptive coding
  • H04N19/146—Data rate or code amount at the encoder output
  • H04N19/147—Data rate or code amount at the encoder output according to rate distortion criteria
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/46—Embedding additional information in the video signal during the compression process
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/85—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using pre-processing or post-processing specially adapted for video compression
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/85—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using pre-processing or post-processing specially adapted for video compression
  • H04N19/89—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using pre-processing or post-processing specially adapted for video compression involving methods or arrangements for detection of transmission errors at the decoder

Definitions

• This disclosure relates to video encoding and video decoding.
• Digital video capabilities can be incorporated into a wide range of devices, including digital televisions, digital direct broadcast systems, wireless broadcast systems, personal digital assistants (PDAs), laptop or desktop computers, tablet computers, e-book readers, digital cameras, digital recording devices, digital media players, video gaming devices, video game consoles, cellular or satellite radio telephones, so-called “smart phones,” video teleconferencing devices, video streaming devices, and the like.
• PDAs personal digital assistants
• laptop or desktop computers tablet computers
• e-book readers digital cameras
• digital recording devices digital media players
• video gaming devices video game consoles
• cellular or satellite radio telephones so-called “smart phones”
• video teleconferencing devices video streaming devices, and the like.
• Digital video devices implement video coding techniques, such as those described in the standards defined by MPEG-2, MPEG-4, ITU-T H.263, ITU-T H.264/MPEG-4, Part 10, Advanced Video Coding (AVC), ITU-T H.265/High Efficiency Video Coding (HEVC), ITU-T H.266/Versatile Video Coding (VVC), and extensions of such standards, as well as proprietary video codecs/formats such as AOMedia Video 1 (AVI) that was developed by the Alliance for Open Media.
• the 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 remove redundancy inherent in video sequences.
• a video slice e.g., a video picture or a portion of a video picture
• video blocks which may also be referred to as coding tree units (CTlJs), coding units (CUs) and/or coding nodes.
• ClJs coding tree units
• CUs coding units
• Video blocks in an intra- coded (I) slice of a picture are encoded using spatial prediction with respect to reference samples in neighboring blocks in the same picture.
• Video blocks in an inter-coded (P or B) slice of a picture may use spatial prediction with respect to reference samples in neighboring blocks in the same picture or temporal prediction with respect to reference samples in other reference pictures.
• Pictures may be referred to as frames, and reference pictures may be referred to as reference frames.
• this disclosure describes techniques for coding video data.
• this disclosure describes techniques for encoding and decoding messages (e.g., supplemental enhancement information (SEI) messages and/or other packetized structures) that include metadata that assist in processing (e.g., decoding, displaying, etc.) video data.
• the messages of this disclosure may include syntax elements that indicate the orientation of a picture and/or transforms to apply to decoded pictures that may be used to rotate and/or mirror the decoded picture into a desired orientation.
• the syntax elements may indicate transforms for an entire picture or constituent pictures (e.g., left and right view stereoscopic pictures) for display.
• the messages may include syntax elements that indicate picture quality metrics.
• the picture quality metrics may indicate the encoding quality of pictures, such as quality-based viewport switching and quality -based metric measurements.
• a video decoder or other device may decode the messages and process pictures of video data in accordance with the messages.
• the picture orientation message may be used to provide, to a video decoder, instructions on recommended orientation transforms to apply to a decoded picture. In this way, the display of the decoded picture may be shown in a more appropriate orientation.
• a video decoder may use the quality metrics in post processing of a decoded picture, and/or may use the quality metrics to select higher quality pictures to use for inter prediction.
• this disclosure describes a method of processing video data, the method comprising receiving a picture, and coding a picture orientation message that includes a transform type syntax element, wherein the transform type syntax element indicates a transform, from among a plurality of transforms, to be applied to the picture .
• this disclosure describes an apparatus configured to process video data, the apparatus comprising a memory configured to store a picture, and one or more processors implemented in circuitry and in communication with the memory, the one or more processors configured to receive the picture, and code a picture orientation message that includes a transform type syntax element, wherein the transform type syntax element indicates a transform, from among a plurality of transforms, to be applied to the picture .
• this 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 that includes a transform type syntax element, wherein the transform type syntax element indicates a transform, from among a plurality of transforms, to be applied to the picture.
• this 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 a picture, and code a picture orientation message that includes a transform type syntax element, wherein the transform type syntax element indicates a transform, from among a plurality of transforms, to be applied to the picture.
• this disclosure describes a method of processing video data, the method comprising receiving a picture, and coding a quality metrics message that includes a quality metric syntax element, wherein the quality metric syntax element indicates a value of a quality metric related to the picture.
• this disclosure describes an apparatus configured to process video data, the apparatus comprising a memory configured to store a picture, and one or more processors implemented in circuitry 7 and in communication with the memory, the one or more processors configured to receive the picture, and code a quality metrics message that includes a quality metric syntax element, wherein the quality metric syntax element indicates a value of a quality metric related to the picture.
• this disclosure describes an apparatus configured to process video data, the apparatus comprising means for receiving a picture, and means for coding a quality metrics message that includes a quality metric syntax element, wherein the quality metric syntax element indicates a value of a quality ' metric related to the picture, [0014]
• this 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 a picture, and code a quality metrics message that includes a quality metric syntax element, wherein the quality metric syntax element indicates a value of a quality metric related to the picture.
• FIG. 1 is a block diagram illustrating an example video encoding and decoding system that may perform the techniques of this disclosure.
• FIG. 2 is a conceptual diagram illustrating an example rotation of a picture.
• FIG. 3 is conceptual diagram illustrating example transform types.
• FIG. 4 is a flowchart illustrating an example process for coding picture orientation supplemental enhancement information messages.
• FIG. 5 is a flowchart illustrating an example process for coding quality metrics supplemental enhancement information messages.
• FIG. 6 is a block diagram illustrating an example video encoder that may perform the techniques of this disclosure.
• FIG. 7 is a block diagram illustrating an example video decoder that may perform the techniques of this disclosure.
• FIG. 8 is a flowchart illustrating an example method for encoding a current block in accordance with the techniques of this disclosure.
• FIG. 9 is a flowchart illustrating an example method for decoding a current block in accordance with the techniques of this disclosure.
• This disclosure describes techniques for encoding and decoding messages (e.g., supplemental enhancement information (SEI) messages and/or other packetized structures) that include metadata that assist in processing (e.g., decoding, displaying, etc.) video data.
• the messages of this disclosure may include syntax elements that indicate the orientation of a picture and/or transforms to apply to decoded pictures that may be used to rotate and/or mirror the decoded picture into a desired orientation.
• the syntax elements may indicate transforms for an entire picture or constituent pictures (e.g., left and right view stereoscopic pictures) for display.
• the messages may include syntax elements that indicate picture quality metrics.
• the picture quality metrics may indicate the encoding quality of pictures, such as quality-based viewport switching and quality -based metric measurements.
• a video decoder or other de vice may decode the messages and process pictures of video data in accordance with the messages.
• the picture orientation message may be used to provide, to a video decoder, instructions on recommended orientation transforms to apply to a decoded picture. In this way, the display of the decoded picture may be shown in a more appropriate orientation .
• a video decoder may use the quality metrics in post processing of a decoded picture, and/or may use the quality metrics to select higher quality pictures to use for inter prediction.
• FIG. 1 is a block diagram illustrating an example video encoding and decoding system 100 that may perform the techniques of this disclosure.
• the techniques of this disclosure are generally directed to coding (encoding and/or decoding) video data.
• video data includes any data for processing a video.
• video data may include raw, imencoded video, encoded video, decoded (e.g., reconstructed) video, and video metadata, such as signaling data.
• 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.
• source device 102 provides the video data to destination device 116 via a computer-readable medium 110.
• Source device 102 and destination device 116 may comprise any of a wide range of devices, including desktop computers, notebook (i.e., laptop) computers, mobile devices, tablet computers, set-top boxes, telephone handsets such as smartphones, televisions, cameras, display devices, digital media players, video gaming consoles, video streaming device, broadcast receiver devices, or the like.
• source device 102 and destination device 116 may be equipped for wireless communication, and thus may be referred to as wireless communication devices.
• source device 102 includes video source 104, memory 106, video encoder 200, and output interface 108.
• video encoder 200 of source device 102 and video decoder 300 of destination device 116 may be configured to apply the techniques for SEI message coding.
• source device 102 represents an example of a video encoding device
• destination device 116 represents an example of a video decoding device.
• a source device and a destination device may include other components or arrangements.
• source device 102 may receive video data from an external video source, such as an external camera.
• destination device 116 may interface with an external display device, rather than include an integrated display device .
• System 100 as shown in FIG. 1 is merely one example.
• any digital video encoding and/or decoding device may perform techniques for SE1 message coding.
• Source device 102 and destination device 116 are merely examples of such coding devices in which 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.
• video encoder 200 and video decoder 300 represent examples of coding devices, in particular, a video encoder and a video decoder, respectively.
• 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.
• system 100 may support one-way or two-way video transmission between source device 102 and destination device 116, e.g., for video streaming, video playback, video broadcasting, or video telephony.
• video source 104 represents a source of video data (i.e., raw, unencoded video data) and provides a sequential series of pictures (also referred to as “frames”) of the video data to video encoder 200, which encodes data tor the pictures.
• Video source 104 of source device 102 may include a video capture device, such as a video camera, a video archive containing previously captured raw video, and/or a video feed interface to receive video from a video content provider.
• video source 104 may generate computer graphics-based data as the source video, or a combination of live video, archived video, and computer-generated video, in each case, video encoder 200 encodes the captured, pre-captured, or computer-generated video data.
• Video encoder 200 may rearrange the pictures from the received order (sometimes referred to as “display order”) into a coding order for coding. Video encoder 200 may generate a bitstream including encoded video data. Source device 102 may then output the encoded video data via output interface 108 onto computer-readable medium 110 for reception and/or retrieval by, e.g., input interface 122 of destination device 116.
• Memory 106 of source device 102 and memory 120 of destination device 116 represent general purpose memories.
• memories 106, 120 may store raw video data, e.g., 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.
• memory 106 and memory 120 are shown separately from video encoder 200 and video decoder 300 in tins example, it should be understood that video encoder 200 and video decoder 300 may also include internal memories for functionally similar or equivalent purposes.
• memories 106, 120 may store encoded video data, e.g., output from video encoder 200 and input to video decoder 300.
• postions of memories 106, 120 may be allocated as one or snore video buffers, e.g., to store raw, decoded, and/or encoded video data.
• Computer-readable medium 110 may represent any type of medium or device capable of transporting the encoded video data from source device 102 to destination device 116.
• computer-readable medium 110 represents a communication medium to enable source device 102 to transmit encoded video data directly to destination de vice 116 in real-time, e.g., via a radio frequency network or computer-based network.
• Output interface 108 may modulate a transmission signal including the encoded video data, and input interface 122 may demodulate the received transmission signal, according to a communication standard, such as a wireless communication protocol.
• the communication medium may comprise any wireless or wired communication medium, such as a radio frequency (RF) spectrum or one or snore physical transmission lines.
• RF radio frequency
• 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.
• the communication mediiun 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.
• source device 102 may output encoded data from output interface 108 to storage device 112.
• destination device 116 may access encoded data from storage device 112 via input interface 122.
• Storage device 112 may include any of a variety of distributed or locally accessed data storage media such as a hard drive, Blu-ray discs, DVDs, CD-ROMs, flash memory, volatile or non-volatile memory, or any other suitable digital storage media for storing encoded video data, [Q035]
• source device 102 may output encoded video data to file server 114 or another intermediate storage device that may store the encoded video data generated by source device 102.
• Destination device 116 may access stored video data from file server 114 via streaming or download.
• Fil e server 114 may be any type of server device capable of storing encoded video data and transmitting that encoded video data, to the destination device 116.
• File server 114 may represent a web server (e.g., for a website), a server configured to provide a file transfer protocol sen/ice (such as File Transfer Protocol (FTP) or File Delivery' over Unidirectional Transport (FLUTE) protocol), a content delivery network (CDN) device, a hypertext transfer protocol (FITTP) server, a Multimedia Broadcast Multicast Sendee (MBMS) or Enhanced MBMS (eMBMS) server, and/or a network attached storage (NAS) device.
• FTP File Transfer Protocol
• FLUTE File Delivery' over Unidirectional Transport
• CDN content delivery network
• FITTP hypertext transfer protocol
• MBMS Multimedia Broadcast Multicast Sendee
• eMBMS Enhanced MBMS
• NAS network attached storage
• 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 (HL8), Real Time Streaming Protocol (RTSP), HTTP Dynamic Streaming, or the like.
• HTTP streaming protocols such as Dynamic Adaptive Streaming over HTTP (DASH), HTTP Live Streaming (HL8), Real Time Streaming Protocol (RTSP), HTTP Dynamic Streaming, or the like.
• Destination device 116 may access encoded video data from file server 114 through any standard data connection, including an internet connection. This may include a wireless channel (e.g., a Wi-Fi connection), a wired connection (e.g., digital subscriber line (DSL), cable modem, etc.), or a combination of both that is suitable for accessing encoded video data stored on file server 114.
• Input interface 122 may be configured to operate according to 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.
• Output interface 108 and input interface 122 may represent wireless transmitters/receivers, modems, wired networking components (e.g., Ethernet cards), wireless communication components that operate according to any of a variety of IEEE 802.11 standards, or other physical components.
• output interface 108 and input interface 122 may be configured to transfer data, such as encoded video data, according to acellular communication standard, such as 4G, 4G-I.TE (Long-Term Evolution), LTE Advanced, 5G, or the like, in some examples where output interface 108 comprises a wireless transmitter, output interface 108 and input interface 122 may be configured to transfer data, such as encoded video data, according to other wireless standards, such as an IEEE 802.11 specification, an IEEE 802.15 specification (e.g., ZigBeeTM), a BluetoothTM standard, or the like.
• source device 102 and/or destination device 116 may include respective system-on-a-chip (SoC) de vices.
• SoC system-on-a-chip
• source device 102 may include an SoC device to perform the functionality attributed to video encoder 200 and/or output interface 108
• destination device 116 may include an SoC device to perform the functionality atributed to video decoder 300 and/or input interface 122
• the techniques of this disclosure may be applied to video coding in support of any of a variety of multimedia applications, such as over-the-air television broadcasts, cable television transmissions, satellite television transmissions, Internet streaming video transmissions, such as dynamic adaptive streaming over HTTP (DASH), digital video that is encoded onto a data storage medium, decoding of digital video stored on a data storage medium, or other applications.
• multimedia applications such as over-the-air television broadcasts, cable television transmissions, satellite television transmissions, Internet streaming video transmissions, such as dynamic adaptive streaming over HTTP (DASH), digital video that is encoded onto a data storage medium, decoding of digital video stored on a data storage medium, or other applications.
• DASH dynamic adaptive streaming over HTTP
• Input interface 122 of destination device 116 receives an encoded video bitstream from computer-readable medium 110 (e.g., a communication medium, storage device 112, file server 114, or the like).
• the encoded video bitstream may include signaling information defined by video encoder 200, which is also used by video decoder 300, such as syntax elements having values that describe characteristics and/or processing of video blocks or other coded units (e.g., slices, pictures, groups of pictures, sequences, or the like).
• Display device 118 displays decoded pictures of the decoded video data to a user.
• Display device 118 may represent any of a variety of display devices such as a liquid crystal display (LCD), a plasma display, an organic light emitting diode (OLED) display, or another type of display device.
• LCD liquid crystal display
• OLED organic light emitting diode
• video encoder 200 and video decoder 300 may each be integrated with an audio encoder and/or audio decoder, and may include appropriate MUX-DEMUX units, or other hardware and/or software, to handle multiplexed streams including both audio and video in a common data stream.
• Video encoder 200 and video decoder 300 each may be implemented as any of a variety of suitable encoder and/or decoder circuitry, such as one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), discrete logic, software, hardware, firmware or any combinations thereof.
• DSPs digital signal processors
• ASICs application specific integrated circuits
• FPGAs field programmable gate arrays
• a 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 this 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 combined encoder/decoder (CODEC) in a respective device.
• a device including video encoder 200 and/or video decoder 300 may comprise an integrated circuit, a microprocessor, and/or a wireless communication device, such as a cellular telephone.
• Video encoder 200 and video decoder 300 may operate according to a video coding standard, such as ITU-T H.265, also referred to as High Efficiency Video Coding (HEVC) or extensions thereto, such as the multi-view and/or scalable video coding extensions.
• 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).
• video encoder 2.00 and video decoder 300 may operate according to a proprietary video codec/format, such as AQMedia Video 1 (AVI), extensions of AVI, and/or successor versions of AVI (e.g., AV2).
• a proprietary video codec/format such as AQMedia Video 1 (AVI), extensions of AVI, and/or successor versions of AVI (e.g., AV2).
• video encoder 200 and video decoder 300 may operate according to other proprietary formats or industry standards. The techniques of this disclosure, however, 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 SEI messages to determine a picture orientation and/or picture quality metrics.
• video encoder 200 and video decoder 300 may perform block-based coding of pictures.
• the term “block” generally refers to a structure including data to be processed (e.g., encoded, decoded, or otherwise used in the encoding and/or decoding process).
• a block may include a two-dimensional matrix of samples of luminance and/or chrominance data.
• video encoder 200 and video decoder 300 may code video data represented in a YUV (e.g., Y, Cb, Cr) format.
• YUV e.g., Y, Cb, Cr
• video encoder 200 and video decoder 300 may code luminance and chrominance components, where the chrominance components may include both red hue and blue hue chrominance components.
• video encoder 200 converts received RGB formatted data to a YUV representation prior to encoding
• video decoder 300 converts the YUV representation to the RGB format.
• pre- and post-processing units may perform these conversions.
• 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.
• this disclosure may refer to coding of blocks of a picture to include the process of encoding or decoding data for the blocks, e.g., prediction and/or residual coding.
• An encoded video bitstream generally includes a series of values for syntax elements representative of coding decisions (e.g., coding modes) and partitioning of pictures into blocks.
• references to coding a picture or a block should generally be understood as coding values for syntax elements forming the picture or block.
• HEVC defines various blocks, including coding units (CUs), prediction units (PUs), and transform units (TUs).
• 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 CTUs and CUs into four equal, non- overlapping squares, and each node of the quadtree has either zero or four child nodes. Nodes without child nodes may be referred to as “leaf nodes,” and 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.
• a residual quadtree represents partitioning of TUs.
• PUs represent inter-prediction data
• TUs represent residual data.
• CUs that are intra-predicted include intra-prediction information, such as an intra-mode indication.
• video encoder 200 and video decoder 300 may be configured to operate according to VVC.
• a video coder such as video encoder 200 partitions a picture into a plurality of coding tree units (CTUs).
• Video encoder 200 may partition a CTU according to a tree structure, such as a quadtree-binary tree (QTBT) structure or Multi -Type Tree (MTT) structure.
• QTBT quadtree-binary tree
• MTT Multi -Type Tree
• the QTBT structure removes the concepts of multiple partition types, such as the separation between CUs, PUs, and TUs of HEVC.
• a QTBT structure includes two levels: a first level partitioned according to quadtree partitioning, and a second level partitioned according to binary tree partitioning.
• a root node of the QTBT structure corresponds to a CTU.
• Leaf nodes of the binary trees correspond to coding units (CUs).
• blocks may be partitioned using a quadtree (QT) partition, a binary tree (BT) partition, and one or more types of triple tree (T ' T) (al so called ternary tree (TT)) partitions.
• QT quadtree
• BT binary tree
• T ' T triple tree
• TT ternary tree
• a triple or ternary' tree partition is a partition where a block is split into three sub-blocks.
• a triple or ternary tree partition divides a block into three sub-blocks without dividing the original block through the center.
• the partitioning types in MTT e.g., QT, BT, and TT
• video encoder 200 and video decoder 300 may be configured to code video data in blocks, in AVI, the largest coding block that can be processed is called a superblock.
• a superblock can be either 128x128 luma samples or 64x64 luma samples.
• successor video coding formats e.g., AV2
• a superblock may be defined by different (e.g., larger) luma sample sizes.
• a superblock is the top level of a block quadtree.
• Video encoder 200 may further partition a superblock into smaller coding blocks.
• Video encoder 200 may partition a superblock and other coding blocks into smaller blocks using square or nonsquare 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 on each of the coding blocks.
• AVI also defines a tile of video data.
• a tile is a rectangular array of superbloeks that may be coded independently of other tiles. That is, video encoder 200 and video decoder 300 may encode and decode, respectively, 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 be uniform or non-uniform in size. Tile-based coding may enable parallel processing and/or multi-threading for encoder and decoder implementations.
• 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 two or more QTBT or MTT structures, such as one QTBT/MTT structure for the luminance component and another QTBT/MTT structure for both chrominance components (or two QTBT/MTT structures for respective chrominance components).
• Video encoder 200 and video decoder 300 may be configured to use quadtree partitioning, QTBT partitioning, MTT partitioning, superblock partitioning, or other partitioning structures.
• a CTU includes a coding tree block (CTB) of luma samples, two corresponding CTBs of chroma samples of a picture that has three sample arrays, or a CTB of samples of a monochrome picture or a picture that is coded using three separate color planes and syntax structures used to code the samples.
• a CTB may be an NxN block of samples tor some value of N such that the division of a component into CTBs is a partitioning.
• a component is an array or single sample from one of the three arrays (luma and two chroma) that compose a picture in 4:2:0, 4:2:2, or 4:4:4 color format or the array or a single sample of the array that compose a picture in monochrome fonnat.
• a coding block is an MxN block of samples for some values of M and N such that a division of a CTB into coding blocks is a partitioning.
• Tiie blocks e.g., CTUs or CUs
• a brick may refer to a rectangular region of CTU rows within a particular tile in a picture.
• a tile may be a rectangular region of CTUs within a particular tile column and a particular tile row* in a picture.
• a tile column refers to a rectangular region of CTU s having a height equal to the height of the picture and a width specified by syntax elements (e.g., such as in a picture parameter set).
• a tile row refers to a rectangular region of CTUs having a height specified by syntax elements (e.g., such as in a picture parameter set) and a width equal to the width of the picture.
• a tile may be partitioned into multiple bricks, each of which may include 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.
• a brick that is a true subset of a tile may not be referred to as a tile.
• the bricks in a picture may also be arranged in a slice,
• a slice may be an integer number of bricks of a picture that may be exclusively contained in a single network abstraction layer (NAL) unit, in some examples, a slice includes either a number of complete tiles or only a consecutive sequence of complete bricks of one tile.
• NAL network abstraction layer
• 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 vertical and horizontal dimensions, e.g., 16x16 samples or 16 by 16 samples.
• an NxN CU generally has N samples in a vertical direction and N samples in a horizontal direction, where N represents a nonnegative integer value.
• the samples in a CU may be arranged in row's and columns.
• CUs need not necessarily have the same number of samples in the horizontal direction as in the vertical direction.
• CUs may comprise MxM samples, where M is not necessarily equal to N,
• Video encoder 200 encodes video data for CUs representing prediction and/or residual information, and other information.
• Hie prediction information indicates how the CU is to be predicted m order to form a prediction block for the CU.
• the residual information generally represents sample-by-sample differences between samples of the CU prior to encoding and the prediction block.
• video encoder 200 may generally form a prediction block for the CU through inter-prediction or intra-prediction.
• Inter-prediction generally refers to predicting the CU from data of a previously coded picture
• intra-prediction generally refers to predicting the CU from previously coded data of the same picture.
• video encoder 200 may generate the prediction block using one or more motion vectors.
• Video encoder 200 may generally perform a motion search to identify a reference block that closely matches the CU, e.g., m terms of differences between the CU and the reference block.
• Video encoder 200 may calculate a difference metric using a sum of absolute difference (SAD), sum of squared differences (SSD), mean absolute difference (MAD), mean squared differences (MSD), or other such difference calculations to determine whether a reference block closely matches the current CU, In some examples, video encoder 200 may predict the current CU using uni -directional prediction or bi-directional prediction.
• SAD sum of absolute difference
• SSD sum of squared differences
• MAD mean absolute difference
• MSD mean squared differences
• VVC also provide an affine motion compensation mode, which may be considered an inter-prediction mode.
• affine motion compensation mode video encoder 200 may determine two or more motion vectors that represent non-transiational motion, such as zoom in or out, rotation, perspective motion, or other irregular motion types.
• video encoder 200 may select an intra-prediction mode to generate the prediction block.
• Some examples of VVC provide sixty-seven intra- prediction modes, including various directional modes, as well as planar mode and DC mode.
• video encoder 200 selects an intra-prediction mode that describes neighboring samples to a current block (e.g., a block of a CU) from which to predict samples of the current block. Such samples may generally be above, above and to the left, or to the left of the current block in the same picture as the current block, assuming video encoder 200 codes CTUs and CUs in raster scan order (left to right, top to bottom).
• Video encoder 200 encodes data representing the prediction mode tor a current block.
• video encoder 200 may encode data representing which of the various available inter-prediction modes is used, as well as motion information for the corresponding mode.
• video encoder 200 may encode motion vectors using advanced motion vector prediction (AMVP) or merge mode.
• AMVP advanced motion vector prediction
• Video encoder 200 may use similar modes to encode motion vectors for affine motion compensation mode.
• AVI includes two general techniques for encoding and decoding a coding block of video data.
• the two general techniques are intra prediction (e.g., intra frame prediction or spatial prediction) and inter prediction (e.g., inter frame prediction or temporal prediction).
• intra prediction e.g., intra frame prediction or spatial prediction
• inter prediction e.g., inter frame prediction or temporal prediction
• video encoder 200 and video decoder 300 do not use video data from other frames of video data.
• video encoder 200 encodes blocks of a current frame based on the difference betw een 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 the reference samples based on the intra prediction mode.
• video encoder 200 may calculate residual data for the block.
• the residual data such as a residual block, represents sample by sample differences between the block and a prediction block for the block, formed using the corresponding prediction mode.
• Video encoder 200 may apply one or more transforms to the residual block, to produce transformed data in a transform domain instead of the sample domain.
• video encoder 200 may apply a discrete cosine transform (DCT), an integer transform, a wavelet transform, or a conceptually similar transform to residual video data.
• DCT discrete cosine transform
• an integer transform an integer transform
• wavelet transform or a conceptually similar transform
• video encoder 200 may apply a secondary transform following the first transform, such as a mode-dependent non-separab!e secondary' transform (MDNSST), a signal dependent transform, a Karhunen-Loeve transform (KLT), or the like.
• Video encoder 200 produces transform coefficients following application of the one or more transforms.
• video encoder 200 may perform quantization of the transform coefficients.
• 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, providing further compression.
• video encoder 200 may reduce the bit depth associated with some or all of the transform coefficients. For example, video encoder 200 may round an «-bit value down to an m-bit value 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.
• video encoder 200 may scan the transform coefficients, producing a one-dimensional vector from the two-dimensional matrix including the quantized transform coefficients.
• the scan may be designed to place higher energy (and therefore lower frequency) transform coefficients at the front of the vector and to place lower energy (and therefore higher frequency ) transform coefficients at the back of the vector.
• video encoder 200 may utilize a predefined scan order to scan the quantized transform coefficients to produce a serialized vector, and then entropy encode the quantized transform coefficients of the vector.
• video encoder 200 may perform an adaptive scan.
• v ideo encoder 200 may entropy encode the one-dimensional vector, e.g., according to context-adaptive binary arithmetic coding (CABAC).
• Video encoder 2.00 may also entropy encode values for syntax elements describing metadata associated with the encoded video data for use by video decoder 300 in decoding tire video data.
• video encoder 200 may assign a context within a context model to a symbol to be transmitted.
• the context may relate to, for example, whether neighboring values of the symbol are zero-valued or not.
• the probability determination may be based on a context assigned to the symbol.
• Video encoder 200 may further generate 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, a block header, a slice header, or other syntax data, such as a sequence parameter set (SPS), picture parameter set (PPS), or video parameter set (VPS) , Video decoder 300 may likewise decode such syntax data to determine how to decode corresponding video data.
• SPS sequence parameter set
• PPS picture parameter set
• VPS video parameter set
• video encoder 200 may generate a bitstream including encoded video data, e.g., syntax elements describing partitioning of a picture into blocks (e.g., CUs) and prediction and/or residual information for the blocks. Ul timately, video decoder 300 may receive the bitstream and decode the encoded video data.
• encoded video data e.g., syntax elements describing partitioning of a picture into blocks (e.g., CUs) and prediction and/or residual information for the blocks.
• video decoder 300 may receive the bitstream and decode the encoded video data.
• video decoder 300 performs a reciprocal process to that performed by video encoder 200 to decode the encoded video data of the bitstream.
• video decoder 300 may decode values for syntax elements of the bitstream using CABAC in a manner substantially similar to, albeit reciprocal to, the CABAC encoding process of video encoder 200.
• the syntax elements may define partitioning information for partitioning of a picture into CTOs, and partitioning of each CTU according to a corresponding partition structure, such as a QTBT structure, to define CUs of the CTU.
• the syntax elements may further define prediction and residual information for blocks (e.g., CUs) of video data,
• the 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 a residual block for the block.
• Video decoder 300 uses a signaled prediction mode (intra- or inter-prediction) and related 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 sample-by-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 boundaries of the block.
• 10071 J Tills disclosure may generally refer to ‘"signaling” certain information, such as syntax elements.
• signaling may generally refer to the communication of values for syntax elements and/or other data used to decode encoded video data. That is, video encoder 200 may signal values for syntax elements in the bitstream, in general, signaling refers to generating a value in the bitstream.
• source device 102 may transport the bitstream to destination device 116 substantially in real time, or not in real time, such as might occur when storing syntax elements to storage device 112. for later retrieval by destination device 116.
• this disclosure describes techniques for coding video data.
• this disclosure describes techniques for decoding SEI messages.
• the SEI messages of this disclosure may include syntax elements that indicate the orientation of a picture.
• the SEI messages may include syntax elements that indicate picture quality metrics.
• a video decoder or other device may decode the SEI messages and process pictures of video data in accordance with the SEI messages.
• VSEI versatile supplemental enhancement information
• ISO/IEC 23002-7 specifies video usability information (VUI) messages and some of the SEI messages used with the VVC bitstream.
• VUI video usability information
• SEi messages enable video encoder 200 to include metadata in the bitstream that is not required tor the correct decoding of the sample values of the output pictures, but can be used for various other purposes.
• Video encoder 200 may be configured to include any number of SEI network abstraction layer (NAL) units in an access unit, and each SET NAL unit may include one or more SEI messages. Specifications and systems using VVC may specify encoders to generate certain SEI messages or may define specific handling of particular types of received SEI messages.
• NAL SEI network abstraction layer
• HEVC High Efficiency Video Coding
• Table 1 Display orientation SEI message syntax for the indications of a horizontal flip (hor flip), v ertical flip (ver flip), and anticlockwise rotation (antieloekwise_rotation) transformations.
• 3GPP specifies a coordination of video orientation (CVO) in the technical specification (TS) 26.114, ’TP Multimedia Subsystem (IMS): Multimedia telephony: Media handling and interaetion, ,! 202.1.
• the CVO signals the current orientation of the image captured on the sender side (e.g., at source device 102) to the receiver (e.g., destination device 116) for approperiate rendering and displaying.
• CVO information for a lower granularity of rotation is carried as a byte formatted as follows, to support horizontal flip and 90 degree rotation:
• LSB least significant bit
• CVO information for a higher granularity of rotation is carried as a byte formatted as follows:
• FIG. 2 shows an example of display rotation of a frame-packed picture where each constituent picture should be rotated, respectively.
• picture 150 includes two constitutent pictures (e.g., a left view picture and a right view picture for stereoscopic video).
• video encoder 200 may send code and SE1 message that include a transform type sytnax element that instructs video decoder 300 to perform a rotation transform on each of the constitutent pictures to achieve transformed picture 152.
• An example VSE1 region-wise packing (RWP) SEI message provides information to enable remapping of the color samples of cropped decoded pictures onto projected pictures.
• the RWP SEI message is used when the omnidirectional video projection is indicated to be applied to a picture.
• An RWP SEI message with the rwp cancel flag equal to 0 shall not be present in the coded layer video sequence (CLVS) that applies to the picture,
• the picture quality relevant ranking is also specified in OMAF, TSO/IEC JTC1/SC29/WG11 N19042, “Text of ISO/IEC DIS 23090-2 2 nd edition OMAF,” 2020, and Immersive Media Metrics (IMM), ISO/IEC JTC1/SC29AVG3 N0073, “IS of ISO/IEC 23090-6 Immersive Media Metrics,” 2020 to facilitate quality' dependent viewport switching and immersive media metrics measurement.
• Some picture quality metrics, such as PSMR and SSIM can only be obtained at the encoder side. An SEI message to carry' such information is able to provide the relevant information to the system application.
• video encoder 200 is configured to generate and signal a picture orientation SEI message that includes one or more syntax elements shown in Table 2 below.
• video encoder 200 may be configured to generate and encode a transform type syntax element (e.g., porjrasisformjype), wherein the transform type syntax element indicates a transform, from among a plurality of transforms, to be applied to a picture.
• 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 the picture orientation SET message and may process and/or display pictures in accordance with the syntax elements contained therein. For example, video decoder 300 may be configured to apply the transform indicated by the transform type sytnax element to a decoded picture.
• Table 2 Picture orientation SEI message syntax inform video decoder 300 of a transform that is recommended to be applied to a decoded picture prior to display.
• the decoded picture may be a cropped picture.
• the value of syntax element por cancel flag indicates that the current SE1 message cancels the persistence of any previous FOR 8EI message in output order.
• the value of syntax element por_cancel_flag equal to 0 indicates that FOR information follows.
• syntax element porjpersistence__flag specifies the persistence of the POR SE1 message for the current layer.
• syntax element por j persistence_flag 0 specifies that the FOR SEI message applies to the current decoded picture only.
• Tiie value of syntax element por_persistence_flag 1 specifies that the POR SEI message applies to the current decoded picture and persists for all subsequent pictures of the current layer in output order until one or more of the following conditions are true:
• a picture in the current layer in an access unit (AU) associated with a POR SEI message is output that follows the current picture in output order.
• syn tax element por constituent picture matching flag 1 specifies that the this SEI message applies individually to each constituent picture and the stereoscopic frame packing format is indicated by the frame packing arrangement SEI message.
• syntax element por_constituentjpicture_matehing_flag 0 specifies that this SEI message applies to the cropped decoded picture.
• StereoFlag is equal to 1 and ip arrangement type is equal to 5.
• StereoFlag 0 indicates the a frame packing arrangement SEI message with fp_arrangernent_eaneel_flag equal to 0 that applies to the pictore is not present.
• Tire value of StereoFlag 1 indicates the associated picture is a frame packing picture.
• syntax element fp arrangement type equal to 5 indicates the component planes of the output cropped decoded pictures in output order form a temporal interleaving of alternating first and second consti tuent frames.
• por_transform_type specifies a transform (e.g., a rotation, mirroring, or a combination of rotation and mirroring) that may be applied to a picture. Note that in some examples, mirroring may be referred to as flipping. When 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, or vice versa.
• Example values of por_transform_type are specified in Table 3 below. In one example, the values of por_transform_type from 8 to 3 i are reserved for future use by ITU-T
• Table 3 por_transfonn_type values The specific values of Table 3 are just one example. In other examples, more or fewer transform types may be specified. Also, the transforms may be specified in different orders than that shown in Table 3.
• FIG. 3 is conceptual diagram illustrating example transform types, in the example of Table 3, when the transform syntax element has a value of 0, video decoder 300 may apply no transform.
• FIG. 3 shows original picture 160 for which no transform is applied.
• the other transform types in FIG. 3 will be shown with refence to original picture 160.
• 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.
• video decoder 300 may apply a 180 degree, anticlockwise rotation transform to original picture 160 to obtain picture 164.
• video decoder 300 may apply a 180 degree, anticlockwise rotation transform, followed by a horizontal mirroring transform, to original picture 160 to obtain picture 166.
• video decoder 300 may apply a 90 degree, anticlockwise rotation transform, followed by a horizontal mirroring transform, to original picture 160 to obtain picture 168.
• video decoder 300 may apply a 90 degree, anticlockwise rotation transform to original picture 160 to obtain picture 170.
• video decoder 300 may apply a 270 degree, anticlockwise rotation transform, followed by a horizontal mirroring transform, to original picture 160 to obtain picture 172.
• video decoder 300 may apply a 270 degree, anticlockwise rotation transform to original picture 160 to obtain picture 174.
• FIG. 4 is a flowchart illustrating an example process for coding picture orientation supplemental enhancement information messages.
• FIG. 4 shows both encoding and decoding processes of the disclosure.
• the encoding processes may be performed by source device 102, including video encoder 200.
• the decoding processes may be performed by destination device 116, including video decoder 300.
• source device 102 may be configured to receive a picture (400).
• Source device 102 may further be configured to encode the picture (e.g., using video encoder 200) and transmit an encoded video bitstream to destination device 116.
• Source device 102 may further be configured to determine a recommend transform type of the picture (402).
• the recommend transform type may be a transform type from among a plurality' of transform types.
• Source device 102 may be further configured to encode a picture orientation message that includes a transform type syntax element, wherein the transform type syntax element indicates a transform, from among a plurality of transforms, to be applied to the picture (404).
• Destination device 116 may be configured to receive the picture (410). Destination device 116 may further be configured to decode the picture (e.g., using video decoder 300). Destination device 116 may also decode the picture orientation message that includes the transform type syntax element, wherein the transform type syntax element indicates a transform, from among a plurality of transforms, to be applied to the picture (412). Destination device 116 may be further configured to apply the transform to the picture in accordance with the transform type syntax element to form a transformed picture (414), and display the transformed picture (416).
• the picture orientation message comprises a picture orientation SEi message
• the picture orientation message comprises a picture orientation open bitstream unit (GBU).
• the plurality of transforms includes two or more of a rotation transform, a mirroring transform, or a combination of a rotation and mirroring transform.
• the plurality of transforms includes a first transform comprising a horizontal mirroring transform, a second transform comprising a 180 degree anticlockwise rotation transform, a third transform comprising the 180 degree anticlockwise transform followed by the horizontal mirroring transform, a fourth transform comprising a 90 degree anticlockwise transform followed by the horizontal mirroring transform, a fifth transform comprising the 90 degree anticlockwise transform, a sixth transform comprising a 270 degree anticlockwise transform followed by the horizontal mirroring transform, and a seventh transform comprising the 270 degree anticlockwise transform.
• the transform type syntax element further includes a value that indicates no transform is to be applied.
• video encoder 200 may signal a high granularity of rotation in the 8EI message.
• the high granularity of rotation and mirroring may apply to each constituent picture.
• a high granularity of rotation my indicate degrees of rotation at relatively small intervals.
• a high granularity of rotation may include rotating pictures at less than 90 degree angles.
• video encoder 2,00 may specify separate orientation transform types or a high granularity of rotation in the SET message or other metadata type, each applying to one constituent picture.
• video encoder 200 may specify a constituent picture matching flag in CVO signaling.
• the constituent picture matching flag may indicate the granularity of rotation that applies to each constituent picture.
• video encoder 200 is configured to generate and signal a picture quality metrics message (e.g., an SEI message and/or other packetized structures) that includes one or more of the syntax element shown in Table 4 below.
• Video decoder 300 is configured to receive the picture quality metrics SEI message and may process and/or display pictures in accordance with the syntax elements contained therein.
• destination device 116 and/or video decoder 300 may be configured to apply one or more post-processing technqiues to a decoded picture in accordance with the quality metrics indicated in the picture quality metrics SEI message.
• An example post-processing technique may include upscaling a decoded picture based on the picture quality.
• video decoder 300 may be configured to use the quality metrics to select certain pcitures to use for inter-prediction. For example, when multiple versions of the same picture are available, video decoder 300 may be configured to select the picture with the highest quality metrics (e.g., lowest signal-to-noise ratio) to use as a reference picture in inter-prediciton.
• Table 4 is one example picture quality metrics SEI message. The picture quality metrics SEI message provides a quality metric for each color component of a current decoded picture.
• Table 4 Picture quality metrics SEI message syntax metric associated with the component as specified in Table 5.
• the values of pqm__metric_type from 4 to 127 are reserved for future use by ITU-T j ISG/TEC and shall not be present in payload data conforming to this version of this Specification.
• the PSNR quality metric type is peak signal-to-noise ratio.
• the SSIM quality metric type is a structural similarity index.
• the MS-SSIM quality metric is a multiscale structural similarity index.
• the VQM quality metric type is a video quality metric.
• the value of syntax element pqm_smgIe_component_flag 1 specifies that the picture associated with the picture quality ' metrics SEI message contains a single color component.
• the value of syntax element pqm single component flag equal to 0 specifies that the picture associated with the picture quality metrics SEI message contains three color components.
• Hie value of syntax element pqm psnr j cidx specifies the value of the PSNR.
• the corresponding PSNR of the color component cidx of the decoded picture is derived as follows (expressed in floating point):
• syntax element pqm_msssim [ cidx ] specifies the value of the MS- SSIM.
• the corresponding MS-SSIM of the color component cidx of the decoded picture is derived as follows (expressed in floating point):
• MS SSIM ( pqm msssim[ cidx ] - 127 ) / 128 [0117]
• the value of syntax element pqm_vqm[ cidx ] specifies the value of the VQM.
• the corresponding VQM of the color component cidx of the decoded picture is derived as follows (expressed in floating point):
• VQM pqm_vqm[ cidx ] / 50
• the picture quality metrics SEI message may carry' other quality relevant metrics such as perceptual evaluation of video quality (PEVQ), mean opinion score (MOS), and/or other picture quality metrics.
• PEVQ perceptual evaluation of video quality
• MOS mean opinion score
• the picture quality metrics SEI message may specify quality metrics tor each constituent picture when the picture is associated with the stereoscopic frame-packing arrangement SEI message.
• the picture quality metrics SEI message may specify’ quality metrics for each region when the picture is associated with the region-wise frame packing SEI message. Additional syntax elements may be added to the SEI message to indicate if picture quality metrics are present for each constituent picture or each region.
• the picture quality metrics SEI message may carry ' ⁇ quality metrics of one or multiple subpictures or regions of interest (ROIs) of the picture associated with the SEI message.
• ROIs regions of interest
• syntax elements indicating the number of subpictures or ROIs, syntax elements indicating the subpictures or ROIs positions, and/or syntax element indicating the subpictures or ROIs sizes may also be specified in the SEI message,
• Additional quality metrics such as weighted PSNR (wPSNR) and weighted-to- sphericaiiy uniform PSNR (WS-PSNR), may be included in the SEI message to indicate the quality of high dynamic range (HDR) and 360 video content.
• wPSNR weighted PSNR
• WS-PSNR weighted-to- sphericaiiy uniform PSNR
• the picture metrics SEI message above provides quality metrics of the current decoded picture .
• syntax element pqm__cnt_mimisl plus I specifies the number of luma component quality metrics that are indicated by the SEI message.
• syntax element pqm_type[ i ] indicates the i-th quality metric type associated with the decoded picture or video sequence as specified in Table 7.
• syntax element pqm_vahie[ i ] specifies the value of the i-th quality metric.
• the stored 16-bit unsigned integer pqm value is interpreted as PSNR value (in dB) as follows (expressed in floating point), with the exception of PSNR equal to infinity for pqm value value equal to 0. integer (e.g., 100).
• the quality 7 metric indicates the average luma PSNR of the CLVS to which the associated picture belongs.
• the 16-bit unsigned integer pqm value is interpreted as a result of a sequence-level PSNR quality metric (in dB), and derived as follows (expressed in floating point), with the exception of PSNR equal to infinity for pqm_value value is equal to 0. integer (e.g., 100).
• the quality' metric indicates the average luma weighted PSNR of the CLVS to which the associated picture belongs.
• the 16-bit unsigned integer pqm_yalue is interpreted as a sequence-level wPSNR value (in dB) as follows (expressed in floating point), with the exception of wPSNR equal to infinity for pqmjvalue value is equal to 0. integer (e.g., 100).
• the quality 7 metric indicates the average luma WS-PSNR of the CLVS to which the associated picture belongs.
• the 16-bit unsigned integer pqm_va!ue is interpreted as a sequence-level WS-PSNR value (in dB) as follows (expressed in floating point), with the exception of WS- PSNR equal to infinity for pqm value value is equal to 0. integer (e.g, 100).
• additional quality metrics types may be included in the SEi message to indicate the average quality metrics that apply to multiple video frames.
• a first syntax element may he specified in the SEI message to indicate that the quality metric specified in the SEI message applies to the associated picture and persists for ail subsequent pictures of the current layer in output order.
• a second syntax element may be specified in the SEI message to cancel the persistence of any pre vious quality metrics in the output order.
• an average quality metric such as a sequence level P8NR
• the associated picture quality SEI message shall be present for the first picture of the CLVS.
• the average picture metric of all SEI messages that apply to the same CLVS shall have the same content.
• FIG. 5 is a flowchart illustrating an example process for coding quality metrics supplemental enhancement information messages.
• FIG. 5 shows both encoding and decoding processes of the disclosure.
• the encoding processes may be performed by source device 102, including video encoder 200.
• the decoding processes may be performed by destination device 116, including video decoder 300.
• source device 102 may be configured to receive a picture (500).
• Source device 102 may further be configured to encode the picture (e.g,, using video encoder 200) and transmit an encoded video bitstream to destination device 116.
• Source device 102 may further be configured to determine a quality metric for picture (502).
• Source device 102 may be further configured to encode a quality- 7 metrics message that includes a quality metric syntax element, wherein the quality metric syntax element indicates a value of a quality metric related to the picture (504).
• source device 102 may be further configured to encode a quality metric type syntax element in the quality metrics message, wherein the quality metric type syntax element indicates a type of quality metric, from among a plurality of types of quality metrics, indicated by the quality metric syntax element.
• the plurality of types of quality metrics includes a peak signal- to-noise ratio (PSNR).
• the plurality of types of quality metrics includes two more of a peak signal -to-noise ratio (PSNR), a structural similarity index (S8IM), a multiscale structural similarity index (MS-SSIM), a video quality metric (VQM), a weighted PSNR (wPSNR), a weighted-to-spherically uniform PSNR (WS- PSNR), a sequence PSNR, a sequence wPSNR, or a sequence WS-PSNR.
• the quality metric syntax element indicates the value of the quality metric indicated by the quality metric type syntax element.
• Destination device 116 may be configured to receive the picture (510). Destination device 116 may further be configured to decode the picture (e.g., using video decoder 300). Destination device 116 may also decode the quality metrics message that includes the quality metric syntax element, wherein the quality metric syntax element indicates the value of the quality metric related to the picture (512). Destination device 116 may be further configured to apply a post-processing technique to the picture in accordance with the value of the quality metric to form a processed picture (514), and display the processed picture (516).
• destination device 116 may be further configured to decode a quality metric type syntax element in the quality metrics message, wherein the quality metric type syntax element indicates a type of quality metric, from among a plurality of types of quality metrics, indicated by the quality metric syntax element.
• the plurality of types of quality metrics includes a peak signal - to-noise ratio (PSNR).
• the plurality of types of quality metrics includes two more of a peak signal-to-noise ratio (PSNR), a structural similarity index (SSIM), a multiscale structural similarity index (MS-SSIM), a video quality metric (VQM), a weighted PSNR (wPSNR), a weigbted-to-spherically uniform PSNR (WS- PSNR), a sequence PSNR, a sequence wPSNR, or a sequence WS-PSNR.
• the quality metric syntax element indicates the value of the quality metric indicated by the quality metric type syntax element.
• the quality metrics message comprises a quality metrics SE1 message.
• the quality metrics message comprises a quality metrics open bitstream unit (OBU).
• OBU quality metrics open bitstream unit
• source device 102 and/or destinati on device 116 may be configured to code a second quality metrics message that includes a second quality metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality metric related to a subpicture or rcgion-of-interest of the picture.
• the above techniques are described in the context of VVC (ITXJ-T H.266, under development), and HEVC (ITU-T H.265).
• the techniques of this disclosure may be performed by video encoding devices that are configured to other video coding standards and video coding formats, such as AVI, future versions of AVI, and successors to the AVI video coding format.
• the messages may be packetized data such as open bitstream units (QBUs) that include at least some of the metadata described in the present disclosure.
• QBUs open bitstream units
• some or all of the above-described syntax included within the picture orientation SEI message may be included within a picture orientation OBU such that the pic ture orien tation OBU includes one or more of a cancel flag, a persistence flag, a constituent picture matching flag, or a transform type syntax element.
• some or all of the above-described syntax Included within the picture quality metrics SEI message may be included within a picture quality metrics OBU such that the picture quality metrics OBU includes one or more syntax elements indicative of a quality metric of the picture.
• FIG. 6 is a block diagram illustrating an example video encoder 200 that may perform the techniques of this disclosure.
• FIG. 6 is provided for memeposes of explanation and should not be considered limiting of the techniques as broadly exemplified and described in this disclosure.
• this disclosure describes video encoder 200 according to the techniques of VVC (ITU-T H.266, under development), and HEVC (ITU-T H.265).
• the techniques of this disclosure may be performed by- video encoding devices that are configured to other video coding standards and video coding formats, such as AVI and successors to the AVI video coding format.
• video encoder 200 includes video data memory 230, mode selection unit 202, residual generation unit 204, transform processing unit 206, quantization unit 2.08, inverse quantization unit 210, inverse transform processing unit 212, reconstruction unit 214, filter unit 216, decoded picture buffer (DPB) 218, and entropy encoding unit 220.
• Any or ail of video data memory 230, mode selection unit 202, residual generation unit 204, transform processing unit 206, quantization unit 208, inverse quantization unit 210, inverse transform processing unit 212, reconstruction unit 214, filter unit 216, DPB 218, and entropy encoding unit 220 may be implemented in one or more processors or in processing circuitry.
• video encoder 200 may be implemented as one or more circuits or logic elements as part of hardware circuitry', or as part of a processor, ASIC, or FPGA.
• 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 the components of video encoder 200.
• Video encoder 200 may receive the video data stored in video data memory 2.30 from, for example, video source 104 (FIG. 1).
• DPB 218 may act as a reference picture memory that stores reference video data for use in prediction of subsequent video data by video encoder 200.
• Video data memory 230 and DPB 218 may be formed by any of a variety of memory devices, such as dynamic random access memory' (DRAM), including synchronous DRAM (SDRAM), magnetoresistive RAM (MRAM), resistive RAM (RRAM), or other types of memory devices.
• DRAM dynamic random access memory'
• SDRAM synchronous DRAM
• MRAM magnetoresistive RAM
• RRAM resistive RAM
• 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- 7 230 may be on-chip with other components of video encoder 200, as illustrated, or off-chip relative to those components.
• reference to video data memory 230 should not be interpreted as being limited to memory 7 internal to video encoder 200, unless specifically described as such, or memory 7 external to video encoder 200, unless specifically described as such. Rather, reference to video data memory 230 should be understood as reference memory that stores video data that video encoder 200 receives for encoding (e.g., video data for a current block that is to be encoded).
• Memory 106 of FIG. 1 may also provide temporary- 7 storage of outputs from the various units of video encoder 200.
• the various units of FIG. 6 are illustrated to assist with understanding 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 particular functionality, and are preset on 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 can be performed. For instance, programmable circuits may execute software or firmware that cause the programmable circuits to operate in the manner defined by instructions of the software or firmware .
• Fixed-function circuits may execute software instructions (e ,g., to receive parameters or output parameters), but the types of operations that the fixed-function circuits perform are generally immutable.
• 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, in examples where the operations of video encoder 200 are performed using software executed by the programmable circuits, memory 106 (FIG. 1) may store the instructions (e.g., object code) of the software that video encoder 200 receives and executes, or another memory within video encoder 200 (not shown) may store such instructions.
• ALUs arithmetic logic units
• EFUs elementary function units
• digital circuits analog circuits
• programmable cores formed from programmable circuits
• memory 106 FIG. 1
• memory 106 may store the instructions (e.g., object code) of the software that video encoder 200 receives and executes, or another memory within video encoder 200 (not shown) may store such instructions.
• Video data memory 230 is configured to store received video data.
• Video encoder 200 may retrieve a picture of the 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 that is to be encoded.
• Mode selection unit 202 includes a motion estimation unit 222, a motion compensation unit 224, and an intra-prediction unit 226.
• Mode selection unit 202 may include additional functional units to perform video prediction in accordance with other prediction modes.
• mode selection unit 202 may include 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, or the like.
• LM linear model
• Mode selection unit 202 generally coordinates multiple encoding passes to test combinations of encoding parameters and resulting rate-distortion values for such combinations.
• the encoding parameters may include partitioning of CTUs into CUs, prediction modes tor the CUs, transform types for residual data of the CUs, quantization parameters for residual data of the CUs, and so on.
• Mode selection unit 202 may ultimately select the combination of encoding parameters having rate-distortion values that are better than the oilier tested combinations.
• Video encoder 200 may partition a picture retrieved from video data memory 2.30 into a series of CTUs, and encapsulate one or more CTUs within a slice.
• Mode selection unit 202 may partition a CTU of the picture in accordance with a tree structure, such as the MTT structure, QTBT structure, superblock structure, or the quad-tree structure described above.
• video encoder 2.00 may form one or more CUs from partitioning a CTU according to the tree structure.
• Such a CU may also be referred to generally as a 'Video block” or “block.”
• mode selection unit 202 also controls the components thereof (e.g., motion estimation unit 222, motion compensation unit 224, and intra-prediction unit 2.26) to generate a prediction block for a current block (e.g., a current CU, or in HEVC, die overlapping portion of a PU and a TU).
• motion estimation unit 222 may perform a motion search to identify one or more closely matching reference blocks in one or more reference pictures (e.g., one or more previously coded pictures stored in DPB 218).
• motion estimation unit 222 may calculate a value representative of how similar a potential reference block is to the current block, e.g., according to sum of absolute difference (SAD), sum of squared differences (SSD), mean absolute difference (MAD), mean squared differences (MSD), or the like.
• Motion estimation unit 2.22 may generally perform these calculations using sample-by-sample differences between the current block and the reference block being considered.
• Motion estimation unit 222 may identify a reference block having a lowest value resulting from these calculations, indicating a reference block that most closely matches the current block.
• Motion estimation unit 222 may form one or more motion vectors (MVs) that defines the positions of the reference blocks in the reference pictures relative to the position of the current block in a current picture. Motion estimation unit 222. may then provide the motion vectors to motion compensation unit 224. For example, for unidirectional inter-prediction, motion estimation unit 222 may provide a single motion vector, whereas for bi-directional inter-prediction, motion estimation unit 222 may provide two motion vectors. Motion compensation unit 224 may then generate a prediction block using the motion vectors. For example, motion compensation unit 224 may retrieve data of the reference block using the motion vector. As another example, if the motion vector has fractional sample precision, motion compensation unit 224 may interpolate values for the prediction block according to one or more interpolation filters.
• MVs motion vectors
• motion compensation unit 224 may retrieve data for two reference blocks identified by respective motion vectors and combine the retrieved data, e.g., through sample-by-sample averaging or weighted averaging.
• Wien operating according to the AV I video coding format motion estimation unit 222 and motion compensation unit 224 may be configured to encode coding blocks of video data (e.g., both luma and chroma coding blocks) using translational motion compensation, affine motion compensation, overlapped block motion compensation (OBMC), and/or compound inter-intra prediction.
• OBMC overlapped block motion compensation
• intraprediction unit 226 may generate the prediction block from samples neighboring the current block. For example, for directional modes, intra-prediction unit 226 may generally mathematically combine values of neighboring samples and populate these calculated values in die defined direction across the current block to produce the prediction block. As another example, for DC mode, intra-prediction unit 226 may calculate an average of the neighboring samples to the current block and generate the prediction block to include this resulting average for each sample of the prediction block.
• intra prediction unit 226 may be configured to encode coding blocks of video data (e.g., both luma and chroma coding blocks) using directional intra prediction, non-direetional intra prediction, recursive filter intra prediction, chroma-from-luma (CFL) prediction, intra block copy (IBC), and/or color palete mode.
• Mode selection unit 202 may include additional functional units to perform video prediction in accordance with other prediction inodes.
• 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 the prediction block from mode selection unit 202.
• Residual generation unit 204 calculates sample-by-sample differences between the current block and the prediction block.
• the resulting sample-by-sample differences define a residual block for the current block, in some examples, residual generation unit 204 may also determine differences between sample values in the residual block to generate a residual block rising residual differential pulse code modulation (RDPCM).
• RPCM residual block rising residual differential pulse code modulation
• residual generation unit 204 may be formed using one or more subtracter circuits that perform binary subtraction.
• 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 having various sizes. As indicated above, the size of a CU may refer to the size of the 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.
• video encoder 200 may support PU sizes of 2Nx2N or NxN for intra prediction, and symmetric PU sizes of 2Nx2N, 2NxN, Nx2N, NxN, or similar for inter prediction.
• Video encoder 200 and video decoder 300 may also support asymmetric partitioning for PU sizes of 2NxnU, 2NxnD, nLx2N, and nRx2N for inter prediction.
• each CU may be associated with a luma coding block and corresponding chroma coding blocks.
• the size of a CU may refer to the size of the luma coding block of the CU.
• the video encoder 200 and video decoder 300 may support CU sizes of 2Nx2N, 2NxN, orNx2N.
• mode selection unit 202 For other video coding techniques such as an intra-biock copy mode coding, an affine-mode coding, and linear model (LM) mode coding, as some examples, mode selection unit 202, via respective units associated with the coding techniques, generates a prediction block for the current block being encoded. In some examples, such as palette mode coding, mode selection unit 202 may not generate a prediction block, and instead generate syntax elements that indicate the manner in which to reconstruct the block based on a selected palette. In such modes, mode selection unit 202 may provide these syntax elements to entropy encoding unit 220 to be encoded.
• mode selection unit 202 via respective units associated with the coding techniques, generates a prediction block for the current block being encoded.
• mode selection unit 202 may not generate a prediction block, and instead generate syntax elements that indicate the manner in which to reconstruct the block based on a selected palette. In such modes, mode selection unit 202 may provide these syntax elements to entropy encoding unit 220 to be encoded.
• residual generation unit 2.04 receives the 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 the 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 transfonns 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 a residual block to form the transform coefficient block.
• 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 a residual block.
• transform processing unit 2.06 may perform multiple transfonns to a residual block, e.g., a primary transform and a secondary transform, such as a rotational transform.
• transform processing unit 206 does not apply transforms to a residual block.
• transform processing unit 206 may apply one or more transfonns 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 a residual block to form the transform coefficient block.
• transform processing unit 206 may apply a horizontal/vertical transform combination that may include a discrete cosine transform (DCT), an asymmetric discrete sme transform (ADST), a flipped ADST (e.g., an ADST in reverse order), and an identity transform (IDTX).
• DCT discrete cosine transform
• ADST asymmetric discrete sme transform
• IDDTX identity transform
• the transform is skipped in one of the vertical or horizontal directions. In some examples, transform processing may he skipped.
• Quantization unit 208 may quantize the transform coefficients in a transform coefficient block, to produce a quantized transform coefficient block. Quantization unit 208 may quanti ze transform coefficients of a transform coefficient block according to a quantization parameter (QP) value associated with the current block. Video encoder 200 (e.g., via mode selection unit 202 ⁇ may adjust the degree of quantization applied to the transform coefficient blocks associated with the current block by adjusting the QP value associated with the CU. Quantization may introduce loss of information, and thus, quantized transform coefficients may have lower precision than the original transform coefficients produced by transform processing unit 206.
• QP quantization parameter
• inverse quantization unit 210 and inverse transform processing unit 212 may apply inverse quantization and inverse transforms to a quantized transform coefficient block, respectively, to reconstruct a residual block from the transform coefficient block.
• Reconstruction unit 214 may produce a reconstructed block corresponding to the current block (albeit potentially with some degree of distortion) based on the reconstructed residual block and a prediction block generated by mode selection unit 202. For example, reconstruction unit 214 may add samples of the reconstructed residual block to corresponding samples from the prediction block generated by mode selection unit 2.02 to produce the reconstructed block.
• Filter unit 216 may perform one or more filter operations on reconstructed blocks. For example, filter unit 216 may perform deblocking operations to reduce blockiness artifacts along edges of CUs. Operations of filter unit 216 may be skipped, in some examples.
• filter unit 216 may perform one or more filter operations on reconstructed blocks. For example, filter unit 216 may perform deblocking operations to reduce blockiness artifacts along edges of CUs. In other examples, filter unit 216 may apply a constrained directional enhancement filter (CDEF), which may be applied after deblocking, and may include the application of non-separable, non-linear, low-pass directional filters based on estimated edge directions. Filter unit 216 may also include a loop restoration filter, which is applied after CDEF, and may include a separable symmetric normalized Wiener filter or a dual self-guided filter.
• CDEF constrained directional enhancement filter
• Video encoder 200 stores reconstructed blocks in DPB 218. For instance, in examples where operations of filter unit 216 are not performed, reconstruction unit 214 may store reconstructed blocks to DPB 218. In examples where operations of filter unit 216 are performed, filter unit 216 may store the filtered reconstructed blocks to DPB 218.
• Motion estimation unit 222 and motion compensation unit 224 may retrieve a reference picture from DPB 218, formed from the reconstructed (and potentially filtered) blocks, to inter-predict blocks of subsequently encoded pictures.
• intra-prediction unit 226 may use reconstructed blocks in DPB 218 of a current picture to intra-predict other blocks in the current picture.
• entropy encoding unit 220 may entropy encode syntax elements received from other functional componen ts of video encoder 200.
• entropy encoding unit 220 may entropy encode quantized transform coefficient blocks from quantization unit 208.
• entropy encoding unit 2.20 may entropy encode prediction syntax elements (e.g., motion information for inter-prediction or intra- mode information for intra-prediction) from mode selection unit 202.
• Entropy encoding unit 220 may perfomi one or more entropy encoding operations on the syntax elements, which are another example of video data, to generate entropy-encoded data.
• entropy encoding unit 220 may perfomi a context-adaptive variable length coding (CAYLC) operation, a CABAC operation, a variable-to-variable (V2V) length coding operation, a syntax-based context-adaptive binary 7 arithmetic coding (SBAC) operation, a Probabi lity interval Partitioning Entropy ' (PIPE) coding operation, an Exponential - Goiomh encoding operation, or another type of entropy encoding operation on the data.
• entropy encoding unit 220 may operate in bypass mode where syntax elements are not entropy encoded.
• Video encoder 200 may output a bitstream that includes the entropy encoded syntax elements needed to reconstruct blocks of a slice or picture.
• entropy encoding unit 220 may output the bitstream.
• entropy encoding unit 220 may be configured as a symbol -to-symbol adaptive multi-symbol arithmetic coder.
• a syntax element in AVI includes an alphabet of N elements, and a context (e.g., probability model) includes a set of N probabilities.
• Entropy encoding unit 220 may store the probabilities as n-bit (e.g., 15-bit) cumulative distribution functions (CDFs).
• Entropy encoding unit 22 may perform recursive scaling, with an update factor based on the alphabet size, to update the contexts.
• the luma coding block and chroma coding blocks are luma and chroma components of a CU.
• the luma coding block and the chroma coding blocks are luma and chroma components ofa PU.
• operations performed with respect to a luma coding block need not be repeated for the chroma coding blocks.
• operations to identify a motion vector (MY) and reference picture for a luma coding block need not be repeated for identifying a MV and reference picture for the chroma blocks.
• 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.
• the intra-prediction process may be the same for the luma coding block and the chroma coding blocks.
• video encoder 200 represents an example of a device configured to encode video data including a memory- 7 configured to store video data, and one or more processing units implemented in circuitry and configured to receive a picture, and encode a picture orientation message that includes a transform type syntax element, wherein the transform type syntax element indicates a transform, from among a plurality of transforms, to be applied to the picture.
• Video encoder 200 may further he configured to encode a quality metrics message that includes a quality metric syntax element, wherein the quality metric syntax element indicates a value of a quality metric related to the picture.
• FIG. 7 is a block diagram illustrating an example video decoder 300 that may perform the techniques of this disclosure.
• FIG. 7 is provided for purposes of explanation and is not limiting on the techniques as broadly exemplified and described in this disclosure.
• this disclosure describes video decoder 300 according to the techniques of VVC (ITU-T H.266, under development), and HE VC (ITU-T H.265).
• VVC ITU-T H.266, under development
• HE VC ITU-T H.265
• the techniques of this disclosure may be performed by video coding devices that are configured to other video coding standards.
• video decoder 300 includes coded picture buffer (CPB) memory- 7 320, entropy decoding unit 302, prediction processing unit 304, inverse quantization unit 306, inverse transform processing unit 308, reconstruction unit 310, filter unit 312, and decoded picture buffer (DPB) 314.
• CPB memory 7 320, 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 may be implemented in one or more processors or in processing circuitry 7 .
• the uni ts of video decoder 300 may be implemented as one or more circuits or logic elements as part of hardware circuitry, 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 intraprediction unit 318. Prediction processing unit 304 may include additional units to perform prediction in accordance with other 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, or the like. In other examples, video decoder 300 may include more, fewer, or different functional components.
• compensation unit 316 may be configured to decode coding blocks of video data (e.g., both luma and chroma coding blocks) using translational motion compensation, affine motion compensation, OBMC, and/or compound inter-intra prediction, as described above
• intra prediction unit 318 may be configured to decode coding blocks of video data (e.g., both luma and chroma coding blocks) using directional intra prediction, non-directional intra prediction, recursive filter intra prediction, CFL, intra block copy (IBC), and/or color palette mode, as described above.
• CPB memory 320 may store video data, such as an encoded video bitstream, to be decoded by the components of video decoder 300.
• the 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 store video data other than syntax elements of a coded picture, such as temporary data representing outputs from the various units of video decoder 300.
• DPB 314 generally stores decoded pictures, which 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 32.0 and DPB 314 may be provided by the same memory ' device or separate memory' devices.
• CPB memory ' 320 may be on-chip with other components of video decoder 300, or off-chip relative to those components.
• video decoder 300 may 7 retrieve coded video data from memory' 120 (FIG. I). 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 processing circuitry of video decoder 300.
• the various units shown in FIG. 7 are illustrated to assist with understanding the operations performed by video decoder 300.
• the units may be implemented as fixed- function circuits, programmable circuits, or a combination thereof. Similar to FIG. 6, fixed-function circuits refer to circuits that provide particular functionality 7 , and are preset on 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 can be performed. For instance, programmable circuits may execute software or firmware that cause the programmable circuits to operate in the manner defined by instructions of the software or firmware.
• Fixed-function circuits may execute software instructions (e.g., to receive parameters or output parameters), but the types of operations that the fixed-function circuits perform are generally immutable.
• one or more of the units may be distinct 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.
• on-chip or off-chip memory may store instructions (e.g., object code) of the software that video decoder 300 receives and executes.
• Entropy decoding unit 302 may receive encoded video data from the 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 may generate decoded video data based on the syntax elements extracted from the bitstream.
• video decoder 300 reconstructs a picture on a block-by-biock basis.
• Video decoder 300 may perform a reconstruction operation on each block individually (where the block currently being reconstructed, i.e., 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 a quantization parameter (QP) and/or transform mode indication(s).
• Inverse quantization unit 306 may use the QP associated with the quantized transform coefficient block to determine a degree of quantization and, likewise, a degree of inverse quantization for inverse quantization unit 306 to apply.
• Inverse quantization unit 306 may, for example, perform a bitwise left-shift operation to inverse quantize the quantized transform coefficients. Inverse quantization unit 306 may thereby form a transform coefficient block including transform coefficients.
• 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.
• inverse transform processing unit 308 may apply an inverse DCT, an inverse integer transform, an inverse Karhunen-Loeve transform (KL ' T), an inverse rotational transtbrm, an inverse directional transform, or another inverse transform to the transform coefficient block.
• prediction processing unit 304 generates a prediction block according to prediction infonnation syntax elements that were 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 the prediction block.
• the prediction information syntax elements may indicate a reference picture in DPB 314 from which to retrieve a reference block, as well as a motion vector identifying a location of the reference block in the reference picture relative to the location of the current block m the current picture.
• Motion compensation unit 316 may generally perform the inter-prediction process in a manner that is substantially similar to that described with respect to motion compensation unit 224 (FIG. 6).
• intra-prediction unit 318 may generate the prediction block according to an intra-prediction mode indicated by the prediction information syntax elements. Again, intra-prediction unit 318 may generally perform the intraprediction process in a manner that is substantially similar to that described with respect to intra-prediction unit 226 (FIG. 6). Intra-prediction unit 318 may retrieve data of neighboring samples to 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 reconstructed blocks.
• filter unit 312. may perform deblocking operations to reduce blockiness artifacts along edges of the reconstructed blocks. Operations of filter unit 312 are not necessarily performed in ail examples.
• Video decoder 300 may store the reconstructed blocks in DPB 314. For instance, in exampl es where operations of filter unit 312. are not performed, reconstruction unit 310 may store reconstructed blocks to DPB 314. In examples where operations of filter unit 312 are performed, filter unit 312 may store the filtered reconstructed blocks to DPB 314. As discussed above, DPB 314 may provide reference information, such as samples of a current picture for intra-prediction and previously decoded pictures for subsequent motion compensation, to prediction processing unit 304. 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.
• decoded pictures e.g., decoded video
• video decoder 300 represents an example of a device configured to decode video data including a memory configured to store video data, and one or more processing units implemented in circuitry and configured to receive a picture, and decode a picture orientation message that includes a transform type syntax element, wherein die transform type syntax element indicates a transform, from among a plurality of transforms, to be applied to the picture.
• Video decoder 300 may further be configured to decode a quality metrics message that includes a quality metric syntax element, wherein the quality metric syntax element indicates a value of a quality metric related to the picture.
• FIG. 8 is a flowchart illustrating an example method for encoding a current block in accordance with the techniques of this disclosure.
• the current block may comprise a current CU.
• video encoder 200 FIGGS. I and 6
• oilier devices may be configured to perform a method similar to that of FIG. 8.
• 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 a 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 transform coefficients of the residual block (354). Next, video encoder 200 may scan the quantized transform coefficients of the residual block (356). During the scan, or following the scan, video encoder 200 may entropy encode the transform coefficients (358). For example, video encoder 200 may encode the transform coefficients using CAVLC or CABAC. Video encoder 2.00 may then output the entropy encoded data of the block (360).
• FIG. 9 is a flowchart illustrating an example method for decoding a current block of video data in accordance with the techniques of this disclosure.
• the current block may comprise a current CU.
• video decoder 300 FIGGS. 1 and 7
• other devices may be configured to perform a method similar to that of FIG. 9.
• Video decoder 300 may receive entropy encoded data for the current block, such as entropy encoded prediction information and entropy encoded data tor 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 to reproduce transform coefficients of the residual block (372). Video decoder 300 may predict the current block (374), 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. Video decoder 300 may then inverse scan the reproduced transform coefficients (376), to create a block of quantized transfonn coefficients. Video decoder 300 may then inverse quantize the transform coefficients and apply an inverse transform to the transform coefficients to produce a residual block (378). Video decoder 300 may ultimately decode the current block by combining the prediction block and the residual block (380).
• entropy encoded data for the current block
• Aspect 1 A A method of processing video data, the method comprising: receiving a picture; and coding a picture orientation supplemental enhancement information (SE1) message that includes one or more of a cancel flag, a persistence flag, a constituent picture matching flag, or a transform type syntax element, wherein the transform type syntax element indicates one or more of a rotation or a mirroring to be applied to the picture.
• SE1 picture orientation supplemental enhancement information
• Aspect 2A The method of Aspect 1A, wherein coding comprises decoding, and wherein the method further comprises: processing the picture in accordance with the picture 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 (8EI) message.
• Aspect 4A The method of Aspect LA or Aspect 2A, wherein the picture orientation message comprises a picture orientation open bitstream unit (QBU).
• QBU picture orientation open bitstream unit
• Aspect 6A - A method of processing video data, the method comprising: receiving a picture; and coding a picture quality metrics supplemental enhancement information (SET) message that includes one or more syntax elements indicative of a quality metric of the picture.
• SET picture quality metrics supplemental enhancement information
• Aspect 7A The method of Aspect 6A, wherein coding comprises decoding, and wherein the method further comprises: processing the picture in accordance with the picture quality metrics SEI message.
• Aspect 8A The method of Aspect 6A or Aspect 7A, wherein the picture orientation message comprises a picture quality metrics supplemental enhancement information (SEI) message.
• SEI picture quality metrics supplemental enhancement information
• Aspect 9A The method of any of Aspects 6A-8A, wherein the picture quality metrics message comprises one or more syntax elements that indicate quality metrics of one or more subpictures or regions of interest of the picture associated with the picture quality metrics message.
• Aspect 10A The method of Aspect 9A, wherein the one or more syntax elements indicate quality metrics of High Dynamic Range (HDR) or 360 video content.
• HDR High Dynamic Range
• Aspect 11A Tire method of any of Aspects 6A-10A, wherein coding comprises encoding.
• Aspect 12A Any combination of methods of Aspects 1A-1QA.
• Aspect I3A A device for processing video data, the device comprising one or more means for performing the method of any of Aspects 1A-I2A.
• Aspect 14A The device of Aspect 13 A, wherein the one or more means comprise one or more processors implemented in circuitry.
• Aspect 15A The device of any of Aspects 13A and I4A, further comprising a memory' to store the 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 stored thereon instructions that, when executed, cause one or more processors to perform the method of any of Aspects 1A-12A.
• Aspect IB - A method of processing video data, the method comprising: receiving a picture; and coding a quality metrics message that includes a quality metric syntax element, wherein the quality metric syntax element indicates a value of a quality metric related to the picture.
• Aspect 3B The method of Aspect 2.B, wherein the plurality of types of quality metrics includes a peak signal-to-noise ratio (PSNR).
• PSNR peak signal-to-noise ratio
• Aspect 4B The method of Aspect 2B, wherein the plurality of types of quality metrics includes two more of a peak signal-to-noise ratio (PSN R), a structural similarity index (S8IM), a multiscale structural similarity index (MS-SSIM), a video quality metric (VQM), a weighted PSNR (wPSNR), a weighted-to-spherically uniform PSNR (WS- PSNR), a sequence PSNR, a sequence wPSNR, or a sequence WS-PSNR.
• PSN R peak signal-to-noise ratio
• S8IM structural similarity index
• MS-SSIM multiscale structural similarity index
• VQM video quality metric
• wPSNR weighted PSNR
• WS- PSNR weighted-to-spherically uniform PSNR
• sequence PSNR a sequence wPSNR
• WS-PSNR a sequence WS-PSNR
• Aspect 5B The method of Aspect 2B, wherein the quality metric syntax element indicates the value of the quality metric indicated by the quality metric type syntax element.
• Aspect 6B The method of Aspect IB, further comprising: coding a second quality metrics message that includes a second quality metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quali ty metric related to a subpicture of the picture.
• Aspect 7B The method of Aspect IB, further comprising: coding a second quality metrics message that includes a second quality metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality metric related to a region-of-interest of the picture.
• Aspect 8B - Hie method of Aspect IB wherein coding comprises decoding, and wherein the method further comprises: applying a post-processing technique to the picture in accordance with the value of the quality metric to fomi a processed picture; and displaying the processed picture.
• Aspect 9B The method of Aspect IB, wherein the quality metrics message comprises a quality metrics supplemental enhancement information (SEI) message
• SEI quality metrics supplemental enhancement information
• Aspect 10B The method of Aspect IB, wherein the quality metrics message comprises a quality metrics open bitstream unit (QBU).
• QBU quality metrics open bitstream unit
• Aspect HB An apparatus configured to process video data, the apparatus comprising: a memory configured to store a picture; and one or more processors implemented in circuitry and in communication with the memory, the one or more processors configured to: receive the picture; and code a quality 7 metrics message that includes a quality metric syntax element, wherein the quality metric syntax element indicates a value of a quality metric related to the picture.
• Aspect 12B - Hie apparatus of Aspect 11B wherein the one or more processors are further 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, from among a plurality of types of quality metrics, indicated by the quality metric syntax element.
• Aspect 13B The apparatus of Aspect 12B, wherein the plurality of types of quality metrics includes a peak signal -to-noise ratio (PSNR).
• PSNR peak signal -to-noise ratio
• Aspect 14B The apparatus of Aspect 12B, wherein the plurality of types of quality metrics includes two more of a peak signal-to-noise ratio (PSNR), a structural similarity index (SSIM), a multiscale structural similarity index (MS-SS1M), a video quality metric (VQM), a weighted PSNR (w ? PSNR), a weighted-to-spherically uniform PSNR (WS-PSNR), a sequence PSNR, a sequence wPSNR, or a sequence WS-PSNR.
• PSNR peak signal-to-noise ratio
• SSIM structural similarity index
• MS-SS1M multiscale structural similarity index
• VQM video quality metric
• Aspect 16B The apparatus of Aspect 11B, wherein the one or more processors are further configured to: code a second quality metrics message that includes a second quality metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality metric related to a subpicture of the picture.
• Aspect 17B The apparatus of Aspect 11B, wherein the one or more processors are further configured to: code a second quality metrics message that includes a second quality metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality metric related to a region-of-interest of the picture.
• Aspect 18B The apparatus of Aspect I IB, wherein the apparatus is configured to decode the quality metrics message, and wherein the one or more processors are further configured to: apply a post-processing technique to the picture in accordance with the value of the quality metric to form a processed picture; and display the processed picture.
• Aspect 19B The apparatus of Aspect 11B, wherein the quality metrics message comprises a quality metrics supplemental enhancement information (SEI) message.
• SEI quality metrics supplemental enhancement information
• Aspect 20B The apparatus of Aspect 11B, wherein the quality metrics message comprises a quality metrics open bitstream unit (OBU).
• OFU quality metrics open bitstream unit
• Aspect 2 IB - An apparatus configured to process video data, the apparatus comprising: means for receiving a picture; and means tor coding a quality metrics message that includes a quality metric syntax element, wherein the quality metric syntax element indicates a value of a quality metric related to the picture.
• Aspect 22.B The apparatus of Aspect 2 IB, 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, from among a plurality of types of quality metrics, indicated by the quality metric syntax element.
• Aspect 23B The apparatus of Aspect 22B, wherein the plurality of Apes of quality metrics includes a peak signal-to-noise ratio (PSNR).
• PSNR peak signal-to-noise ratio
• Aspect 24B The apparatus of Aspect 22B, wherein the plurality of types of quality metrics includes two more of a peak signal-to-noise ratio (PSNR), a structural similarity index (SSIM), a multiscale structural similarity index (MS-SSIM), a video quality metric (VQM), a weighted PSNR (wPSNR), a weighted-to-spherically uniform PSNR (WS-PSNR), a sequence PSNR, a sequence wPSNR, or a sequence WS-PSNR.
• PSNR peak signal-to-noise ratio
• SSIM structural similarity index
• MS-SSIM multiscale structural similarity index
• VQM video quality metric
• wPSNR weighted PSNR
• WS-PSNR weighted-to-spherically uniform PSNR
• Aspect 26B The apparatus of Aspect 2. IB. further comprising: means for coding a second quality metrics message that includes a second quality metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality metric related to a subpicture of the picture.
• Aspect 27B The apparatus of Aspect 2 IB, further comprising: means for coding a second quality metrics message that includes a second quality 7 metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality metric related to a region-of-interest of the picture.
• Aspect 28B The apparatus of Aspect 2 IB, wherein the means for coding comprises means for decoding, and wherein the apparatus further comprises: means for applying a post-processing technique to the picture in accordance with the value of the quality metric to form a processed picture; and means for displaying the processed picture.
• Aspect 29B The apparatus of Aspect 2 IB, wherein the quality metrics message comprises a quality metrics supplemental enhancement Information (SEI) message.
• SEI quality metrics supplemental enhancement Information
• Aspect 30B The apparatus of Aspect 2 IB, wherein the quality metrics message comprises a quality metrics open bitstream unit (OBU).
• OFU quality metrics open bitstream unit
• Aspect 3 IB - 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 a picture; and code a quality metrics message that includes a quality metric syntax element, wherein the quality metric syntax element indicates a value of a quality metric related to the picture.
• Aspect 32B The non-transitory computer-readable storage medium of Aspect 3 IB, wherein the instructions further cause the one or more processors 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, from among a plurality of types of quality metrics, indicated by the quality metric syntax element.
• Aspect 33B The non-transitory computer-readable storage medium of Aspect 32B, wherein the plurality of types of quality metrics includes a peak signal-to-noise ratio (PSNR).
• PSNR peak signal-to-noise ratio
• Aspect 34B The non-transitory computer-readable storage medium of Aspect 32, wherein the plurality of types of quality metrics includes two more of a peals signal- to-noise ratio (PSNR), a structural similarity index (SSIM), a multiscale structural similarity index (M8-8SIM), a video quality metric (VQM), a weighted PSNR (wPSNR), a weighted-to-spherically uniform PSNR (WS-PSNR), a sequence PSNR, a sequence wPSNR, or a sequence WS-PSNR.
• PSNR peals signal- to-noise ratio
• SSIM structural similarity index
• M8-8SIM multiscale structural similarity index
• VQM video quality metric
• wPSNR weighted PSNR
• WS-PSNR weighted-to-spherically uniform PSNR
• sequence PSNR a sequence wPSNR, or a sequence WS-PSNR.
• Aspect 36B The non-transitory computer-readable storage medium of Aspect 3 IB, wherein the instructions further cause the one or more processors to: code a second quality metrics message that includes a second quality metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality metric related to a subpieture of the picture.
• Aspect 37B The non-transitory computer-readable storage medium of Aspect 3 IB, wherein the instructions further cause the one or more processors to: code a second quality' metrics message that includes a second quality metric syntax element, wherein tire second quality metric syntax element indicates a second value of a second quality metric related to a region-of-interest of the picture.
• Aspect 38B The non-transitory ' computer-readable storage medium of Aspect 3 I B, wherein the device is configured to decode the quality metrics message, aud wherein the instructions further cause the one or more processors to: apply a post-processing technique to the picture in accordance with the value of the quality metric to form a processed picture; and display the processed picture.
• Aspect 39B The non-transitory computer-readable storage medium of Aspect SIB, wherein the quality metrics message comprises a quality metrics supplemental enhancement information (SEI) message.
• SEI quality metrics supplemental enhancement information
• Aspect 40B The non-transitory ' computer-readable storage medium of Aspect 31 B, wherein the quality metrics message comprises a quality metrics open bitstream uni t (OBU).
• OBU quality metrics open bitstream uni t
• Aspect 1C - A method of processing video data, the method comprising: receiving a picture; aud coding a quality metrics message that includes a quality- 7 metric syntax element, wherein the quality metric syntax elemen t indicates a value of a quality metric related to the picture.
• 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 indicates a type of quality metric, from among a plurality of types of quality metrics, indicated by the quality metric syntax element.
• Aspect 3C The method of Aspect 2.C, wherein the plurality of types of quality metrics includes a peak signal-to-noise ratio (PSNR).
• Aspect 4C The method of Aspect 2C, wherein the plurality of types of quality metrics includes two more of a peak signal-to-noise ratio (PSNR), a structural similarity index (SSIM), a multiscale structural similarity index (MS-SSIM), a video quality metric (VQM), a weighted PSNR (wPSNR), a weighted-to-spherically uniform PSNR (WS- PSNR), a sequence PSNR, a sequence wPSNR, or a sequence WS-PSNR.
• PSNR peak signal-to-noise ratio
• SSIM structural similarity index
• MS-SSIM multiscale structural similarity index
• VQM video quality metric
• wPSNR weighted PSNR
• WS- PSNR weighted-to-spherically uniform PSNR
• sequence PSNR a
• Aspect 6C - Hie method of any of Aspects 1C-5C further comprising: coding a second quality metrics message that includes a second quality metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality 7 metric related to a subpicture of the picture.
• Aspect 7C The method of any of Aspects 1C-5C, further comprising: coding a second quality metrics message that includes a second quality metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality metric related to a region-of-interest of the picture.
• Aspect 8C The method of any of Aspects 1C-7C, wherein coding comprises decoding, and wherein the method further comprises: applying a post-processing technique to the picture in accordance with the value of the quality metric to form a processed picture; and displaying the processed picture.
• Aspect 9C The method of any of Aspects 1C-8C, wherein the quality metrics message comprises a quality metrics supplemental enhancement information (SE1) message.
• SE1 quality metrics supplemental enhancement information
• QBU quality metrics open bitstream unit
• Aspect i iC An apparatus configured to process video data, the apparatus comprising: a memory configured to store a picture; and one or more processors implemented in circuitry and in communication with the memory, the one or more processors configured to: receive the picture; and code a quality 7 metrics message that includes a quality metric syntax element, wherein the quality metric syntax element indicates a value of a quality metric related to the picture.
• Aspect 12C The apparatus of Aspect 11C, wherein the one or more processors are further 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, from among a plurality of types of quality metrics, indicated by the quality metric syntax element.
• PSNR peak signal-to-noise ratio
• Aspect I4C The apparatus of Aspect 12C, wherein the plurality of types of quality metrics includes two more of a peak signal-to-noise ratio (PSNR), a structural similarity index (SSIM), a multiscale structural similarity index (MS-SSIM), a video quality metric (VQM), a weighted PSNR (wPSNR), a weighted-to-spherically uniform PSNR (WS-PSNR), a sequence PSNR, a sequence wPSNR, or a sequence WS-PSNR.
• PSNR peak signal-to-noise ratio
• SSIM structural similarity index
• MS-SSIM multiscale structural similarity index
• VQM video quality metric
• wPSNR weighted PSNR
• WS-PSNR weighted-to-spherically uniform PSNR
• Aspect 16C The apparatus of any of Aspects 11C- 15 C, wherein tire one or more processors are further configured to: code a second quality metrics message that includes a second quality 7 metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality metric related to a subpicture of the picture.
• Aspect 17C The apparatus of any of Aspects 11C-15C, wherein the one or more processors are further configured to: code a second quality metrics message that includes a second quality 7 metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality metric related to a region-of-interest of the picture.
• Aspect 18C The apparatus of any of Aspects 11C-17C, wherein the apparatus is configured to decode the quality metrics message, and wherein the one or more processors are further configured to: apply a post-processing technique to the picture in accordance with the value of the quality metric to form a processed picture; and display the processed picture .
• Aspect 19C The apparatus of any of Aspects 11C-18C, wherein the quality metrics message comprises a quality metrics supplemental enhancement information (SEI) message.
• SEI quality metrics supplemental enhancement information
• Aspect 20C The apparatus of any of Aspects 11C-18C, wherein the quality metrics message comprises a quality metrics open bitstream unit (OBU).
• OBU quality metrics open bitstream unit
• Aspect 21C An apparatus configured to process video data, the apparatus comprising: means for receiving a picture; and means for coding a quality metrics message that includes a quality metric syntax element, wherein the quality metric syntax element indicates a value of a quality metric related to the picture.
• Aspect 22 C The apparatus 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 indicates a type of quality metric, from among a plurality of types of quality metrics, indicated by the quality metric syntax element.
• P8NR peak signal -to-noise ratio
• Aspect 24C The apparatus of Aspect 22C, wherein the plurality of types of quality metrics includes two more of a peak signai-to-noise ratio (PSNR), a structural similarity index (8S1M), a multiscale structural similarity index (MS-SSIM), a video quality 7 metric (VQM), a weighted PSNR (wPSNR), a weighted-to-spherically uniform PSNR (WS-PSNR), a sequence PSNR, a sequence wPSNR, or a sequence WS-PSNR.
• PSNR peak signai-to-noise ratio
• 8S1M structural similarity index
• MS-SSIM multiscale structural similarity index
• VQM video quality 7 metric
• wPSNR weighted PSNR
• WS-PSNR weighted-to-spherically uniform PSNR
• sequence PSNR a sequence wPSNR
• WS-PSNR a sequence WS-PSNR
• Aspect 26C The apparatus of any of Aspects 21C-25C, further comprising: means for coding a second quality metrics message that includes a second quality metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality metric related to a subpicture of the picture.
• Aspect 27C The apparatus of any of Aspects 21C-25C, further comprising: means for coding a second quality metrics message that includes a second quality metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality metric related to a region-of-interest of the picture.
• Aspect 28C The apparatus of any of Aspects 21C-27C, wherein the means for coding comprises means for decoding, and wherein the apparatus further comprises: means for applying a post-processing technique to die picture in accordance with the value of the quality metric to form a processed picture; and means tor displaying the processed picture.
• Aspect 29C The apparatus of any of Aspects 2IC-28C, wherein the quality metrics message comprises a quality metrics supplemental enhancement iufonnation (SEI) message.
• SEI quality metrics supplemental enhancement iufonnation
• Aspect 30C The apparatus of any of Aspects 2IC ⁇ 2.BC, wherein the quality metrics message comprises a quality metrics open bitstream unit (OBU).
• OBU quality metrics open bitstream unit
• Aspect 32C The non-transitory computer-readable storage medium of Aspect 31C, wherein the instructions further cause the one or more processors 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, from among a plurality of types of quality metrics, indicated by the quality metric syntax element.
• Aspect 33C the non-transitory computer-readable storage medium of Aspect 32C, wherein the plurality of types of quality metrics includes a peak signal-to-noise ratio
• Aspect 34C The non-transitory computer-readable storage medium of Aspect 32, wherein the plurality of types of quality metrics includes two more of a peak signal- to-noise ratio (PSNR), a structural similarity index (SSIM), a multiscale structural similarity index (MS-SSIM), a video quality metric (VQM), a weighted PSNR (wPSNR), a weighted-to-sphericaily uniform PSNR (WS-PSNR), a sequence PSNR, a sequence wPSNR, or a sequence WS-PSNR.
• PSNR peak signal- to-noise ratio
• SSIM structural similarity index
• MS-SSIM multiscale structural similarity index
• VQM video quality metric
• wPSNR weighted PSNR
• WS-PSNR weighted-to-sphericaily uniform PSNR
• Aspect 35C The non-transitory computer-readable storage medium of any of Aspects 32C-34C, wherein the quality metric syntax element indicates the value of the quality metric indicated by the quality metric type syntax element.
• Aspect 36C The non-transitory computer-readable storage medium of any of Aspects 31C-35C, wherein the instructions further cause the one or more processors to: code a second quality metrics message that includes a second quality metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality metric related to a subpicture of the picture.
• Aspect 37C The non-transitory computer-readable storage medium of any of Aspects 31C-35C, wherein the instructions further cause the one or more processors to: code a second quality metrics message that includes a second quality metric syntax element, wherein the second quality metric syntax element indicates a second value of a second quality metric related to a region-of-interest of the picture.
• Aspect 38C The non-transitory computer-readable storage medium of any of Aspects 31C-37C, wherein the device is configured to decode the quality metrics message, and wherein the instructions further cause the one or snore processors to: apply a post-processing technique to the picture in accordance with the value of the quality metric to fomi a processed picture; and display the processed picture.
• 8EI quality metrics supplemental enhancement information
• Aspect 40C The non-transitory computer-readable storage medium of any of Aspects 3 IC-38C, wherein the quality metrics message comprises a quality metrics open bitstream unit (OBU).
• OBU quality metrics open bitstream unit
• Computer-readable media may include computer-readable storage media, which corresponds to a tangible medium such as data storage media, or communication media including any medium that facilitates transfer of a computer program from one place to another, e.g., according to a communication protocol.
• computer-readable media generally may correspond to (1) tangible computer-readable storage media which is non-transitory or (2) a communication medium such as a signal or carrier wave.
• Data storage media may be any available media that can be accessed by one or more computers or one or more processors to retrieve instructions, code and/or data structures for implementation of the techniques described in this disclosure.
• a computer program product may include a computer-readable medium.
• such computer-readable storage media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, or other magnetic storage devices, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly tenned a computer- readable medium.
• coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave are included in the definition of medium.
• DSL digital subscriber line
• computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other transitory media, but are instead directed to non-transitory, tangible storage media.
• Disk and disc includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc, where disks usually reproduce data magnetically, w hile discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.
• processors such as one or more DSPs, general purpose microprocessors, ASICs, FPGAs, or other equivalent integrated or discrete logic circuitry.
• processors such as one or more DSPs, general purpose microprocessors, ASICs, FPGAs, or other equivalent integrated or discrete logic circuitry.
• processors such as one or more DSPs, general purpose microprocessors, ASICs, FPGAs, or other equivalent integrated or discrete logic circuitry.
• processors such as one or more DSPs, general purpose microprocessors, ASICs, FPGAs, or other equivalent integrated or discrete logic circuitry.
• 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.
• the functionality' described herein may be provided within dedicated hardware and/or software modules configured for encoding and decoding, or incorporated in a combined codec.
• the techniques could be fully implemented in one or more circuits or logic elements.
• Pie techniques of this disclosure may be implemented in a wade variety of devices or apparatuses, including a wareless handset, an integrated circuit (IC) or a set of ICs (e.g., a chip set).
• IC integrated circuit
• a set of ICs e.g., a chip set.
• Various components, modules, or units are described in this disclosure to emphasize functional aspects of devices configured to perform the disclosed techniques, but do not necessarily require real ization by different hardware units. Rather, as described above, various units may be combined in a codec hardware unit or provided by a collection of interoperative hardware units, including one or more processors as described above, in conjunction with suitable software and/or firmware.

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• Compression Or Coding Systems Of Tv Signals (AREA)
• Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)

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