METHOD AND APPARATUS FOR VIDEO CODING - Patent application

Abstract

To provide methods, apparatuses, and non-transitory computer-readable storage mediums for video encoding / decoding.SOLUTION: An apparatus includes processing circuitry that receives metadata associated with a coded video bitstream. The metadata includes labeling information of one or more objects detected in a first picture that is coded in the coded video bitstream. The processing circuitry decodes the labeling information of the one or more objects in the first picture that is coded in the coded video bitstream. The processing circuitry applies the labeling information to the one or more objects in the first picture.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Application No. 63 / 135,530, entitled "SIGNALING OF OBJECTS FOR MACHINE TASKS," filed January 8, 2021, which claims the benefit of priority to U.S. Patent Application No. 17 / 459,753, entitled "METHOD AND APPARATUS FOR VIDEO CODING," filed August 27, 2021. The entire disclosures of the prior applications are incorporated by reference in their entirety into this application.

[0002] This disclosure generally describes embodiments related to video coding. [Background technology]

[0003] The discussion of the background art provided herein is intended to provide a general context for the present disclosure. The work of the inventors named herein, to the extent that their work is described in this background art section, and aspects of the description that may not otherwise qualify as prior art at the time of filing, are not admitted, expressly or impliedly, as prior art to the present disclosure.

[0004] Video coding and decoding can be performed using inter-picture prediction with motion compensation. Uncompressed digital video may include a series of pictures, each with spatial dimensions of, for example, 1920 x 1080 luminance samples and associated chrominance samples. The series of pictures may have a fixed or variable picture rate (also informally known as a frame rate), for example, 60 pictures per second or 60 Hz. Uncompressed video has significant bitrate requirements. For example, 1080p60 4:2:0 video (1920 x 1080 luminance sample resolution at a 60 Hz frame rate) with 8 bits per sample requires a bandwidth approaching 1.5 Gbit / s. One hour of such video requires more than 600 GBytes of storage space.

[0005] One goal of video coding and decoding can be reducing redundancy in the input video signal through compression. Compression can help reduce the aforementioned bandwidth or storage space requirements, sometimes by more than two orders of magnitude. Both lossless and lossy compression, as well as combinations of these, can be used. Lossless compression refers to techniques in which an exact copy of the original signal can be reconstructed from the compressed original signal. With lossy compression, the reconstructed signal may not be identical to the original signal, but the distortion between the original and reconstructed signal is small enough to make the reconstructed signal useful for the intended application. For video, lossy compression is widely adopted. The amount of acceptable distortion depends on the application; for example, users of certain consumer streaming applications may tolerate higher distortion than users of television distribution applications. The achievable compression ratio may reflect that higher acceptable / tolerable distortion can result in a higher compression ratio.

[0006] Video encoders and decoders may utilize techniques from several broad categories, including, for example, motion compensation, transform, quantization, and entropy coding.

[0007] Video codec technology may include a technique known as intra-coding. In intra-coding, sample values ​​are represented without reference to samples or other data from previously reconstructed reference pictures. In some video codecs, pictures are spatially subdivided into blocks of samples. When all blocks of samples are coded in intra mode, the picture may be an intra-picture. Intra-pictures and their derivatives, such as independent decoder refresh pictures, can be used to reset the decoder state and therefore may be used as the first picture in a coded video bitstream and video session or as a still image. Samples of intra-blocks may be subjected to a transform, and the transform coefficients may be quantized before entropy coding. Intra-prediction may be a technique that minimizes sample values ​​in the pre-transform domain. In some cases, the smaller the DC value and the smaller the AC coefficients after the transform, the fewer bits are required at a given quantization step size to represent the block after entropy coding.

[0008] For example, conventional intra-coding, such as that known from MPEG-2 generation coding techniques, does not use intra-prediction. However, some newer video compression techniques include techniques that rely on surrounding sample data and / or metadata obtained during the encoding and / or decoding of spatially adjacent and preceding data blocks in decoding order. Such techniques are hereinafter referred to as "intra-prediction" techniques. Note that, at least in some cases, intra-prediction uses only reference data from the current picture being reconstructed, and does not use reference data from reference pictures.

[0009] Intra-prediction can take many different forms. When two or more of such techniques can be used in a given video coding technique, the technique in use can be coded in intra-prediction mode. In certain cases, a mode can have sub-modes and / or parameters, which can be coded separately or included in the mode's codeword. The codeword used for a given mode, sub-mode, and / or parameter combination can affect coding efficiency gains via intra-prediction, and therefore can also affect the entropy coding technique used to convert the codeword into a bitstream.

[0010] Certain modes of intra prediction were introduced in H.264, improved in H.265, and further refined in newer coding techniques such as the joint exploration model (JEM), versatile video coding (VVC), and benchmark sets (BMS). Predictor blocks can be formed using neighboring sample values ​​belonging to already available samples. The sample values ​​of the neighboring samples are copied into the predictor block according to the direction. A reference to the direction in use may be coded in the bitstream or may itself be predicted.

[0011] Referring to FIG. 1A, depicted at the bottom right is a subset of nine known predictor directions from the 33 possible predictor directions (corresponding to the 33 angular modes of the 35 intra modes) in H.265. The point where the arrows converge (101) represents the sample being predicted. The arrows represent the direction from which the sample is predicted. For example, arrow (102) indicates that sample (101) is predicted from one or more samples to the upper right and at an angle of 45 degrees from horizontal. Similarly, arrow (103) indicates that sample (101) is predicted from one or more samples to the lower left of sample (101) at an angle of 22.5 degrees from horizontal.

[0012] 1A, a square block (104) of 4x4 samples (indicated by a thick dashed line) is depicted in the upper left. The square block (104) contains 16 samples, each labeled with "S," its position in the Y dimension (e.g., row index), and its position in the X dimension (e.g., column index). For example, sample S21 is the second sample (from the top) in the Y dimension and the first sample (from the left) in the X dimension. Similarly, sample S44 is the fourth sample in both the Y and X dimensions within the block (104). Because the block is 4x4 samples in size, S44 is located in the lower right. Reference samples, which follow a similar numbering scheme, are also shown. The reference samples are labeled R, their Y position (e.g., row index), and their X position (column index) relative to the block (104). In both H.264 and H.265, negative values ​​need not be used because the predicted samples are adjacent to the block being reconstructed.

[0013] Intra-picture prediction may work by copying reference sample values ​​from adjacent samples as assigned by the signaled prediction direction. For example, assume that the coded video bitstream includes signaling indicating a prediction direction consistent with the arrow (102) for this block, i.e., the sample is predicted from one or more prediction samples located to the upper right at a 45-degree angle from the horizontal. In this case, samples S41, S32, S23, and S14 are predicted from the same reference sample R05. Then, sample S44 is predicted from reference sample R08.

[0014] In certain cases, the values ​​of multiple reference samples may be combined, for example by interpolation, to calculate a reference sample, especially when the direction is not evenly divisible by 45 degrees.

[0015] The number of possible directions has increased as video coding technology has evolved. In H.264 (2003), nine different directions could be represented. This increased to 33 in H.265 (2013), and as of the time of this disclosure, JEM / VVC / BMS can support up to 65 directions. Experiments have been conducted to identify the most likely directions, and specific entropy coding techniques are used to represent these likely directions with a small number of bits, accepting a certain penalty for less likely directions. Furthermore, the direction itself may be predicted from neighboring directions used in adjacent, already decoded blocks.

[0016] Figure 1B shows a schematic diagram (105) showing 65 intra-prediction directions with JEM to illustrate the increasing number of prediction directions over time.

[0017] The mapping of intra-prediction direction bits in a coded video bitstream to represent directions may vary from one video coding technique to another, ranging, for example, from a simple direct mapping of prediction directions to intra-prediction modes to complex adaptation schemes involving codewords, most likely modes, and similar techniques. However, in all cases, there may be certain directions that are statistically less likely to occur in the video content than certain other directions. Because the goal of video compression is to reduce redundancy, these less likely directions are represented by more bits than more likely directions in well-performing video coding techniques.

[0018] Motion compensation may be a lossy compression technique in which blocks of sample data from a previously reconstructed picture or portion thereof (reference picture) are spatially shifted in a direction indicated by a motion vector (hereinafter, MV) and then used to predict a newly reconstructed picture or portion thereof. In some cases, the reference picture may be the same as the picture currently being reconstructed. The MV may have two dimensions, X and Y, or three dimensions, with the third dimension being an indication of the reference picture in use (the latter may indirectly be a temporal dimension).

[0019] In some video compression techniques, the MV applicable to a particular region of sample data can be predicted from other MVs, e.g., from an MV associated with another region of sample data that is spatially adjacent to the region being reconstructed and precedes that MV in decoding order. Doing so can significantly reduce the amount of data required to code the MV, resulting in the elimination of redundancy and increased compression. For example, when coding an input video signal derived from a camera (known as natural video), MV prediction can work effectively because regions larger than the region to which a single MV is applicable move in similar directions and therefore, in some cases, there is a statistical likelihood that the MV can be predicted using a similar MV derived from the MVs of neighboring regions. This results in the MV found for a given region being similar or identical to the MV predicted from surrounding MVs, and as a result, after entropy coding, it can be represented with fewer bits than would be used to code the MV directly. In some cases, MV prediction can be an example of lossless compression of a signal (i.e., an MV) derived from the original signal (i.e., a sample stream). In other cases, the MV prediction itself can be lossy, for example, due to rounding errors when calculating a predictor from several surrounding MVs.

[0020] Various MV prediction mechanisms are described in H.265 / HEVC (ITU-T Rec. H.265, "High Efficiency Video Coding", December 2016). Among the many MV prediction mechanisms provided by H.265, a technique hereafter referred to as "spatial merging" is described herein.

[0021] Referring to Figure 1C, the current block (111) may contain samples found by the encoder during a motion search process that are predictable from a spatially shifted previous block of the same size. Instead of coding its MV directly, the MV may be derived from metadata associated with one or more reference pictures, e.g., the most recent reference picture (in decoding order), using the MV associated with any one of five surrounding samples represented by A0, A1, and B0, B1, B2 (112 to 116, respectively). In H.265, MV prediction may use a predictor from the same reference picture as neighboring blocks. Summary of the Invention [Means for solving the problem]

[0022] An aspect of the present disclosure provides an apparatus for video encoding / decoding. The apparatus includes a processing circuit that receives metadata associated with a coded video bitstream. The metadata includes labeling information of one or more objects detected in a first picture coded in the coded video bitstream. The processing circuit decodes the labeling information of the one or more objects in the first picture coded in the coded video bitstream. The processing circuit applies the labeling information to the one or more objects in the first picture.

[0023] In one embodiment, the metadata is included in supplementary enhancement information (SEI) messages within the coded video bitstream.

[0024] In one embodiment, the metadata is contained in a separate file from the coded video bitstream.

[0025] In one embodiment, the labeling information indicates the total number of bounding boxes in the first picture and includes position information and size information for each bounding box, each bounding box being associated with one object of the one or more objects in the first picture.

[0026] In one embodiment, the labeling information includes category information indicating a category for each of the one or more objects.

[0027] In one embodiment, the labeling information includes identification information that identifies each of the one or more objects in the video sequence.

[0028] In one embodiment, the position information of one of the bounding boxes includes a position offset of the one of the bounding boxes between the first picture and a second picture coded in the video bitstream.

[0029] In one embodiment, the position information for one of the bounding boxes indicates a position outside the first picture relative to one of the bounding boxes based on an object associated with the one of the bounding boxes that is not present in the first picture.

[0030] In one embodiment, the processing circuitry transmits a request to receive metadata associated with a coded video bitstream.

[0031] An aspect of the present disclosure provides a method for video encoding / decoding. The method may perform any one or a combination of processes performed by an apparatus for video encoding / decoding. In the method, metadata associated with a coded video bitstream is received. The metadata includes labeling information of one or more objects detected in a first picture coded in the coded video bitstream. The labeling information of one or more objects in the first picture coded in the coded video bitstream is decoded. The labeling information is applied to one or more objects in the first picture.

[0032] Aspects of the present disclosure also provide a non-transitory computer-readable medium storing instructions that, when executed by at least one processor, cause the at least one processor to perform any one or combination of methods for video encoding / decoding.

[0033] Further features, nature and various advantages of the disclosed subject matter will become more apparent from the following detailed description and accompanying drawings. [Brief explanation of the drawings]

[0034] [Figure 1A] FIG. 2 is a schematic diagram of an example subset of intra-prediction modes. [Figure 1B] FIG. 1 is a diagram of an exemplary intra-prediction direction. [Figure 1C] FIG. 1 is a schematic diagram of a current block and its surrounding spatial merge candidates in one example. [Figure 2] FIG. 1 is a schematic diagram of a simplified block diagram of a communication system according to one embodiment. [Figure 3] FIG. 1 is a schematic diagram of a simplified block diagram of a communication system according to one embodiment. [Figure 4] FIG. 2 is a schematic diagram of a simplified block diagram of a decoder according to one embodiment. [Figure 5] FIG. 2 is a schematic diagram of a simplified block diagram of an encoder according to one embodiment. [Figure 6] FIG. 4 is a block diagram of an encoder according to another embodiment. [Figure 7] FIG. 10 is a block diagram of a decoder according to another embodiment. [Figure 8] FIG. 1 is a diagram of an exemplary architecture used in machine-based video coding (VCM) according to one embodiment. [Figure 9] FIG. 1 illustrates an exemplary encoder for use in generic video coding (VVC) according to one embodiment. [Figure 10] FIG. 1 is an exemplary flowchart according to one embodiment. [Figure 11] FIG. 1 is a schematic diagram of a computer system according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0035] I. Video Decoder and Encoder Systems Figure 2 shows a simplified block diagram of a communication system (200) according to one embodiment of the present disclosure. The communication system (200) includes multiple terminal devices that may communicate with each other, for example, via a network (250). For example, the communication system (200) includes a first pair of terminal devices (210) and (220) interconnected via the network (250). In the example of Figure 2, the first pair of terminal devices (210) and (220) perform unidirectional transmission of data. For example, the terminal device (210) may code video data (e.g., a stream of video pictures captured by the terminal device (210)) for transmission to another terminal device (220) via the network (250). The encoded video data may be transmitted in the form of one or more coded video bitstreams. The terminal device (220) may receive the coded video data from the network (250), decode the coded video data to reconstruct the video pictures, and display the video pictures according to the reconstructed video data. Unidirectional data transmission may be common, such as in media serving applications.

[0036] In another example, the communication system (200) includes a second pair of terminal devices (230) and (240) that perform bidirectional transmission of coded video data, such as may occur during a video conference. For the bidirectional transmission of data, in one example, each of the terminal devices (230) and (240) may code video data (e.g., a stream of video pictures captured by the terminal device) for transmission to the other of the terminal devices (230) and (240) over the network (250). Each of the terminal devices (230) and (240) may also receive coded video data transmitted by the other of the terminal devices (230) and (240), decode the coded video data to reconstruct video pictures, and display the video pictures on an accessible display device according to the reconstructed video data.

[0037] In the example of FIG. 2 , terminal devices 210, 220, 230, and 240 may be depicted as a server, a personal computer, and a smartphone, although the principles of the present disclosure may not be so limited. Embodiments of the present disclosure are contemplated for use with laptop computers, tablet computers, media players, and / or dedicated videoconferencing equipment. Network 250 represents any number of networks that convey coded video data between terminal devices 210, 220, 230, and 240, including, for example, wired and / or wireless communication networks. Communication network 250 may exchange data over circuit-switched and / or packet-switched channels. Exemplary networks include telecommunications networks, local area networks, wide area networks, and / or the Internet. For purposes of this description, the architecture and topology of network 250 may not be important to the operation of the present disclosure, unless otherwise described herein below.

[0038] 3 illustrates the arrangement of a video encoder and a video decoder in a streaming environment as an example of an application of the disclosed subject matter. The disclosed subject matter may be equally applicable to other video-enabled applications, including, for example, video conferencing, digital TV, storage of compressed video on digital media including CDs, DVDs, memory sticks, and the like.

[0039] The streaming system may include a video source (301), e.g., a capture subsystem (313), which may include a digital camera, generating a stream of uncompressed video pictures (302). In one example, the stream of video pictures (302) includes samples taken by the digital camera. The stream of video pictures (302), shown as a thick line to emphasize its high data volume compared to the encoded video data (304) (or coded video bitstream), may be processed by an electronic device (320) including a video encoder (303) connected to the video source (301). The video encoder (303) may include hardware, software, or a combination thereof to enable or implement aspects of the disclosed subject matter, as described in more detail below. The encoded video data (304) (or coded video bitstream (304)), shown as a thin line to emphasize its lower data volume compared to the stream of video pictures (302), may be stored on a streaming server (305) for future use. One or more streaming client subsystems, such as the client subsystems (306) and (308) of Figure 3, may access the streaming server (305) to retrieve copies (307) and (309) of the encoded video data (304). The client subsystem (306) may include a video decoder (310), for example, within an electronic device (330). The video decoder (310) decodes an input copy (307) of the encoded video data and generates an output stream of video pictures (311) that can be rendered on a display (312) (e.g., a display screen) or other rendering device (not shown). In some streaming systems, the encoded video data (304), (307), and (309) (e.g., a video bitstream) may be encoded according to a particular video coding / compression standard. Examples of such standards include ITU-T Recommendation H.265.In one example, a video coding standard under development is informally known as Versatile Video Coding (VVC), and the disclosed subject matter may be used in the context of VVC.

[0040] It should be noted that the electronic devices (320) and (330) may include other components (not shown). For example, the electronic device (320) may include a video decoder (not shown), and the electronic device (330) may also include a video encoder (not shown).

[0041] 4 shows a block diagram of a video decoder (410) according to one embodiment of the present disclosure. The video decoder (410) may be included in an electronic device (430). The electronic device (430) may include a receiver (431) (e.g., a receiving circuit). The video decoder (410) may be used in place of the video decoder (310) in the example of FIG. 3.

[0042] The receiver (431) can receive one or more coded video sequences to be decoded by the video decoder (410), in the same or another embodiment, one coded video sequence at a time, with the decoding of each coded video sequence being independent of the other coded video sequences. The coded video sequences can be received from a channel (401), which can be a hardware / software link to a storage device that stores the encoded video data. The receiver (431) can receive the encoded video data along with other data, such as a coded audio data stream and / or ancillary data stream, which can be forwarded to a respective using entity (not shown). The receiver (431) can separate the coded video sequences from other data. To combat network jitter, a buffer memory (415) can be connected between the receiver (431) and the entropy decoder / parser (420) (hereinafter "parser (420)"). In certain applications, the buffer memory (415) is part of the video decoder (410). In other applications, the buffer memory may be external to the video decoder (410) (not shown). In still other applications, there may be a buffer memory (not shown) external to the video decoder (410), for example, to combat network jitter, plus another buffer memory (415) internal to the video decoder (410), for example, to handle playout timing. When the receiver (431) is receiving data from a storage / forwarding device with sufficient bandwidth and controllability or from an isosynchronous network, the buffer memory (415) may not be needed or may be small. For use with best-effort packet networks such as the Internet, the buffer memory (415) may be needed, may be relatively large, may advantageously be adaptively sized, and may be implemented at least partially within an operating system or similar element (not shown) external to the video decoder (410).

[0043] The video decoder (410) may include a parser (420) for reconstructing symbols (421) from the coded video sequence. These symbol categories include information used to manage the operation of the video decoder (410) and, in some cases, information for controlling a rendering device (e.g., a display screen), such as the render device (412) that is not an integral part of the electronic device (430) but may be connected to the electronic device (430), as shown in FIG. 4. Control information for the rendering device may be in the form of a Supplemental Enhancement Information (SEI) message or a Video Usability Information (VUI) parameter set fragment (not shown). The parser (420) may parse / entropy decode the received coded video sequence. The coding of the coded video sequence may conform to a video coding technique or standard and may follow various principles, including variable length coding, Huffman coding, and arithmetic coding with or without context sensitivity. The parser (420) may extract from the coded video sequence a set of subgroup parameters for at least one of the subgroups of pixels in the video decoder based on at least one parameter corresponding to the group. The subgroup may include a group of pictures (GOP), a picture, a tile, a slice, a macroblock, a coding unit (CU), a block, a transform unit (TU), a prediction unit (PU), etc. The parser (420) may also extract from the coded video sequence information such as transform coefficients, quantizer parameter values, and MVs.

[0044] The parser (420) may perform entropy decoding / parsing operations on the video sequence received from the buffer memory (415) to generate symbols (421).

[0045] The reconstruction of the symbols (421) may involve several different units, depending on the type of coded video picture or portion thereof (e.g., inter-picture and intra-picture, inter-block and intra-block) and other factors. Which units are involved and how may be controlled by subgroup control information parsed from the coded video sequence by the parser (420). The flow of such subgroup control information between the parser (420) and the following units is not shown for clarity.

[0046] Beyond the functional blocks already described, the video decoder (410) may be conceptually subdivided into several functional units, as described below. In an actual implementation operating under commercial constraints, many of these units may interact closely with each other and may be at least partially integrated with each other. However, for purposes of describing the disclosed subject matter, the following conceptual subdivision into functional units is appropriate.

[0047] The first unit is a scalar / inverse transform unit (451), which receives quantized transform coefficients as well as control information from the parser (420) as symbols (421), including which transform to use, block size, quantization factor, quantization scaling matrix, etc. The scalar / inverse transform unit (451) may output blocks containing sample values ​​that may be input to an aggregator (455).

[0048] In some cases, the output samples of the scaler / inverse transform (451) may relate to intra-coded blocks, i.e., blocks that do not use prediction information from a previously reconstructed picture but may use prediction information from a previously reconstructed portion of the current picture. Such prediction information may be provided by an intra-picture prediction unit (452). In some cases, the intra-picture prediction unit (452) generates blocks of the same size and shape as the block being reconstructed using surrounding already reconstructed information fetched from a current picture buffer (458). The current picture buffer (458), for example, buffers a partially reconstructed and / or fully reconstructed current picture. In some examples, the aggregator (455) adds, on a sample-by-sample basis, prediction information already generated by the intra-prediction unit (452) to the output sample information provided by the scaler / inverse transform unit (451).

[0049] In other cases, the output samples of the scalar / inverse transform unit (451) may relate to an inter-coded, potentially motion-compensated block. In such cases, the motion-compensated prediction unit (453) may access a reference picture memory (457) to fetch samples used for prediction. After motion-compensating the fetched samples according to the symbols (421) related to the block, these samples (in this case referred to as residual samples or residual signals) may be added to the output of the scalar / inverse transform unit (451) by an aggregator (455) to generate output sample information. The addresses in the reference picture memory (457) from which the motion-compensated prediction unit (453) fetches prediction samples may be controlled by MVs available to the motion-compensated prediction unit (453), for example, in the form of symbols (421) that may have X, Y, and reference picture components. Motion compensation may also include interpolation of sample values ​​fetched from the reference picture memory (457) when sub-sample accurate MVs are used, MV prediction mechanisms, etc.

[0050] The output samples of the aggregator (455) may be subjected to various loop filtering techniques in a loop filter unit (456). Video compression techniques may include in-loop filter techniques controlled by parameters contained in the coded video sequence (also called a coded video bitstream) and made available to the loop filter unit (456) as symbols (421) from the parser (420), but may also be responsive to meta-information obtained during decoding of a coded picture or previous portion (in decoding order) of the coded video sequence, as well as to previously reconstructed, loop-filtered sample values.

[0051] The output of the loop filter unit (456) may be a sample stream that may be output to a render device (412) and stored in a reference picture memory (457) for use in future inter-picture prediction.

[0052] Once fully reconstructed, a particular coded picture can be used as a reference picture for future prediction. For example, once a coded picture corresponding to a current picture is fully reconstructed and the coded picture is identified as a reference picture (e.g., by the parser (420)), the current picture buffer (458) can become part of the reference picture memory (457), and a new current picture buffer can be relocated before beginning reconstruction of a subsequent coded picture.

[0053] The video decoder (410) may perform decoding operations according to a predetermined video compression technique in a standard, such as ITU-T Rec. H.265. The coded video sequence may conform to the syntax specified by the video compression technique or standard being used, in the sense that the coded video sequence adheres to both the syntax of the video compression technique or standard and the profile documented in the video compression technique or standard. Specifically, the profile may select some tools from all tools available in the video compression technique or standard as the only tools available for use under that profile. Compliance may also require that the complexity of the coded video sequence be within a range defined by the level of the video compression technique or standard. In some cases, the level limits the maximum picture size, maximum frame rate, maximum reconstruction sample rate (e.g., measured in megasamples per second), maximum reference picture size, etc. The limits set by the level may, in some cases, be further constrained by a Hypothetical Reference Decoder (HRD) specification and metadata for HRD buffer management signaled in the coded video sequence.

[0054] In one embodiment, the receiver (431) may receive additional (redundant) data with the encoded video. The additional data may be included as part of the coded video sequence. The additional data may be used by the video decoder (410) to properly decode the data and / or to more accurately reconstruct the original video data. The additional data may be in the form of, for example, temporal, spatial, or signal-to-noise ratio (SNR) enhancement layers, redundant slices, redundant pictures, forward error correction codes, etc.

[0055] 5 shows a block diagram of a video encoder (503) according to one embodiment of the present disclosure. The video encoder (503) is included in an electronic device (520). The electronic device (520) includes a transmitter (540) (e.g., a transmission circuit). The video encoder (503) may be used in place of the video encoder (303) of the example of FIG. 3.

[0056] The video encoder (503) may receive video samples from a video source (501) (not part of the electronic device (520) in the example of FIG. 5) that may capture video images to be coded by the video encoder (503). In other examples, the video source (501) is part of the electronic device (520).

[0057] The video source (501) may provide a source video sequence coded by the video encoder (503) in the form of a digital video sample stream, which may be of any suitable bit depth (e.g., 8-bit, 10-bit, 12-bit, ...), any color space (e.g., BT.601 Y CrCB, RGB, ...), and any suitable sampling structure (e.g., Y CrCb 4:2:0, Y CrCb 4:4:4). In a media presentation system, the video source (501) may be a storage device that stores already prepared video. In a video conferencing system, the video source (501) may be a camera that captures local image information as a video sequence. Video data may be provided as multiple individual pictures that convey motion when viewed sequentially. The pictures themselves may be organized as a spatial array of pixels, and each pixel may contain one or more samples, depending on the sampling structure, color space, etc., in use. Those skilled in the art will readily understand the relationship between pixels and samples. The following description focuses on samples.

[0058] According to one embodiment, the video encoder (503) may code and compress pictures of a source video sequence into a coded video sequence (543) in real time or under any other time constraint required by the application. Achieving an appropriate coding rate is one function of the controller (550). In some embodiments, the controller (550) controls and is operatively connected to other functional units as described below. For clarity, connections are not shown. Parameters set by the controller (550) may include rate control-related parameters (picture skip, quantizer, lambda value for rate-distortion optimization techniques, ...), picture size, group of pictures (GOP) layout, and maximum MV allowed reference region. The controller (550) may be configured with other appropriate functions associated with the video encoder (503) optimized for a particular system design.

[0059] In some embodiments, the video encoder (503) is configured to operate in a coding loop. As an overly simplified explanation, in one example, the coding loop may include a source coder (530) (e.g., responsible for generating symbols, such as a symbol stream, based on an input picture to be coded and a reference picture) and a (local) decoder (533) embedded in the video encoder (503). The decoder (533) reconstructs symbols to generate sample data in a manner similar to that generated by a (remote) decoder (when any compression between the symbols and the coded video bitstream is lossless in the video compression techniques considered in the disclosed subject matter). The reconstructed sample stream (sample data) is input to a reference picture memory (534). Because decoding of the symbol stream produces bit-exact results regardless of the location (local or remote) of the decoder, the contents of the reference picture memory (534) are also bit-exact between the local encoder and the remote encoder. In other words, the prediction part of the encoder "sees" the exact same sample values ​​as the reference picture samples that the decoder "sees" when using prediction during decoding. This basic principle of reference picture synchrony (and the resulting drift if synchrony cannot be maintained, e.g., due to channel error) is also used in several related technologies.

[0060] The operation of the "local" decoder (533) may be the same as the operation of a "remote" decoder, such as the video decoder (410), already described in detail above in connection with Figure 4. However, with brief reference also to Figure 4, because symbols are available and the encoding / decoding of symbols into / from a coded video sequence by the entropy coder (545) and parser (420) may be lossless, the entropy decoding portion of the video decoder (410), including the buffer memory (415) and parser (420), may not be implemented entirely in the local decoder (533).

[0061] At this point, it can be said that any decoder technology, other than parsing / entropy decoding, present in a decoder must also necessarily exist in substantially the same functional form in the corresponding encoder. For this reason, the disclosed subject matter focuses on the operation of the decoder. A description of the encoder technology can be omitted, since it is the reverse of the decoder technology described generically. Only in certain areas is a more detailed description necessary, as will be provided below.

[0062] In operation, in some examples, the source coder (530) may perform motion-compensated predictive coding, which predictively codes an input picture with reference to one or more previously coded pictures from a video sequence designated as “reference pictures.” In this manner, the coding engine (532) codes differences between pixel blocks of the input picture and pixel blocks of reference pictures that may be selected as predictive references for the input picture.

[0063] The local video decoder (533) may decode coded video data of pictures that may be designated as reference pictures based on symbols generated by the source coder (530). The operation of the coding engine (532) may preferably be a lossy process. When the coded video data is decoded by a video decoder (not shown in FIG. 5), the reconstructed video sequence may typically be a copy of the source video sequence with some errors. The local video decoder (533) may replicate the decoding process that may be performed by the video decoder on the reference pictures and store the reconstructed reference pictures in a reference picture cache (534). In this way, the video encoder (503) may locally store copies of reconstructed reference pictures that have common content as reconstructed reference pictures that will be retrieved (without transmission errors) by the far-end video decoder.

[0064] The predictor (535) may perform a predictive search for the coding engine (532). That is, for a new picture to be coded, the predictor (535) may search the reference picture memory (534) for sample data (as candidate reference pixel blocks) or specific metadata, such as reference picture MV and block shape, that may serve as an appropriate predictive reference for the new picture. The predictor (535) may operate on a sample block-by-pixel block basis to find an appropriate predictive reference. In some cases, as determined by the search results obtained by the predictor (535), the input picture may have predictive references drawn from multiple reference pictures stored in the reference picture memory (534).

[0065] The controller (550) may manage the coding operations of the source coder (530), including, for example, setting the parameters and subgroup parameters used to encode the video data.

[0066] The outputs of all the aforementioned functional units may be subjected to entropy coding in an entropy coder (545), which converts the symbols produced by the various functional units into a coded video sequence by losslessly compressing the symbols according to techniques such as Huffman coding, variable length coding, or arithmetic coding.

[0067] The transmitter (540) may buffer the coded video sequence produced by the entropy coder (545) and prepare it for transmission over a communication channel (560), which may be a hardware / software link, to a storage device that stores the encoded video data. The transmitter (540) may merge the coded video data from the video coder (503) with other data to be transmitted, such as coded audio data and / or auxiliary data streams (sources not shown).

[0068] The controller (550) may manage the operation of the video encoder (503). During coding, the controller (550) may assign a particular coded picture type to each coded picture, which may affect the coding technique that may be applied to the respective picture. For example, pictures are often assigned as one of the following picture types:

[0069] An intra picture (I-picture) may be one that can be coded and decoded without using any other picture in a sequence as a prediction source. Some video codecs allow various types of intra pictures, including, for example, independent decoder refresh ("IDR") pictures. Those skilled in the art are aware of these variations of I-pictures and their respective uses and characteristics.

[0070] A predicted picture (P picture) may be one that can be coded and decoded using intra prediction or inter prediction, which uses at most one MV and reference index to predict the sample values ​​of each block.

[0071] A bidirectionally predicted picture (B picture) may be coded and decoded using intra- or inter-prediction, which uses up to two MVs and reference indices to predict the sample values ​​of each block. Similarly, a multi-predicted picture may use more than two reference pictures and associated metadata for the reconstruction of a single block.

[0072] A source picture is generally spatially subdivided into multiple sample blocks (e.g., blocks of 4x4, 8x8, 4x8, or 16x16 samples each) and may be coded block by block. Blocks may be predictively coded with reference to other (already coded) blocks, as determined by the coding assignment applied to the block's respective picture. For example, blocks of an I-picture may be non-predictively coded, or they may be predictively coded with reference to already coded blocks of the same picture (spatial prediction or intra-prediction). Pixel blocks of a P-picture may be predictively coded via spatial prediction or via temporal prediction with reference to one previously coded reference picture. Blocks of a B-picture may be predictively coded via spatial prediction or via temporal prediction with reference to one or two previously coded reference pictures.

[0073] The video encoder (503) may perform coding operations according to a predetermined video coding technique or standard, such as ITU-T Rec. H.265. In doing so, the video encoder (503) may perform various compression operations, including predictive coding operations that exploit temporal and spatial redundancy in the input video sequence. Thus, the coded video data may conform to a syntax specified by the video coding technique or standard being used.

[0074] In one embodiment, the transmitter (540) may transmit additional data along with the encoded video. The source coder (530) may include such data as part of the coded video sequence. The additional data may include temporal / spatial / SNR enhancement layers, other forms of redundant data such as redundant pictures and slices, SEI messages, VUI parameter set fragments, etc.

[0075] Video may be captured in time sequence as multiple source pictures (video pictures). Intra-picture prediction (often abbreviated as intra-prediction) exploits spatial correlation within a given picture, while inter-picture prediction exploits correlation (temporal or other) between pictures. In one example, a particular picture being encoded / decoded, called the current picture, is divided into blocks. If a block in the current picture is similar to a reference block in a previously coded and still buffered reference picture in the video, the block in the current picture may be coded by a vector called a MV. The MV refers to a reference block in the reference picture and may have a third dimension that identifies the reference picture if multiple reference pictures are used.

[0076] In some embodiments, inter-picture prediction may use a bi-prediction technique. According to the bi-prediction technique, two reference pictures, such as a first reference picture and a second reference picture, are used, both of which are before the current picture in the video in decoding order (but may be past and future, respectively, in display order). A block in the current picture may be coded by a first MV that points to a first reference block in the first reference picture and a second MV that points to a second reference block in the second reference picture. A block may be predicted by a combination of the first reference block and the second reference block.

[0077] Furthermore, in inter-picture prediction, merge mode techniques may be used to improve coding efficiency.

[0078] According to some embodiments of the present disclosure, predictions such as inter-picture prediction and intra-picture prediction are performed on a block-by-block basis. For example, according to the HEVC standard, pictures in a sequence of video pictures are divided into coding tree units (CTUs) for compression, and the CTUs within a picture have the same size, such as 64x64 pixels, 32x32 pixels, or 16x16 pixels. Generally, a CTU includes three coding tree blocks (CTBs), one luma CTB and two chroma CTBs. Each CTU may be recursively quadtree-decomposed into one or more coding units (CUs). For example, a 64x64 pixel CTU may be divided into one CU of 64x64 pixels, four CUs of 32x32 pixels, or 16 CUs of 16x16 pixels. In one example, each CU is analyzed to determine the CU's prediction type, such as an inter-prediction type or an intra-prediction type. A CU is divided into one or more prediction units (PUs) according to temporal and / or spatial predictability. Generally, each PU includes one luma prediction block (PB) and two chroma PBs. In one embodiment, prediction operations in coding (encoding / decoding) are performed in units of prediction blocks. Using a luma prediction block as an example of a prediction block, the prediction block includes a matrix of pixel values ​​(e.g., luma values) of 8x8 pixels, 16x16 pixels, 8x16 pixels, 16x8 pixels, etc.

[0079] 6 shows a diagram of a video encoder (603) according to another embodiment of the present disclosure. The video encoder (603) is configured to receive a processed block (e.g., a predictive block) of sample values ​​in a current video picture in a sequence of video pictures and to encode the processed block into a coded picture that is part of the coded video sequence. In one example, the video encoder (603) is used in place of the video encoder (303) of the example of FIG. 3.

[0080] In an HEVC example, the video encoder (603) receives a matrix of sample values ​​for a processing block, such as a predicted block of 8x8 samples. The video encoder (603) determines whether the processing block is best coded using intra-mode, inter-mode, or bi-predictive mode, e.g., using rate-distortion optimization. If the processing block is to be coded in intra-mode, the video encoder (603) may use intra-prediction techniques to encode the processing block into a coded picture; if the processing block is to be coded in inter-mode or bi-predictive mode, the video encoder (603) may use inter-prediction or bi-prediction techniques, respectively, to encode the processing block into a coded picture. In certain video coding techniques, the merge mode may be an inter-picture prediction sub-mode, and the MVs are derived from one or more MV predictors without the benefit of coded MV components outside the predictors. In certain other video coding techniques, there may be MV components applicable to the current block. In one example, the video encoder (603) includes other components, such as a mode decision module (not shown), to determine the mode of the processing block.

[0081] In the example of Figure 6, the video encoder (603) includes an inter-encoder (630), an intra-encoder (622), a residual calculator (623), a switch (626), a residual encoder (624), a general controller (621), and an entropy encoder (625), which are connected to each other as shown in Figure 6.

[0082] The inter-encoder (630) is configured to receive samples of a current block (e.g., a processing block), compare the block with one or more reference blocks in a reference picture (e.g., blocks in a previous picture and a subsequent picture), generate inter-prediction information (e.g., description of redundant information by inter-encoding technique, MV, merge mode information), and calculate an inter-prediction result (e.g., a predictive block) based on the inter-prediction information using any suitable technique. In some examples, the reference picture is a decoded reference picture that is decoded based on the encoded video information.

[0083] The intra encoder (622) is configured to receive samples of a current block (e.g., a processing block), possibly compare the block with previously coded blocks in the same picture, generate quantized coefficients after transformation, and possibly also generate intra prediction information (e.g., intra prediction direction information according to one or more intra encoding techniques). In one example, the intra encoder (622) also calculates intra prediction results (e.g., predicted blocks) based on the intra prediction information and reference blocks in the same picture.

[0084] The general-purpose controller (621) is configured to determine general-purpose control data and control other components of the video encoder (603) based on the general-purpose control data. In one example, the general-purpose controller (621) determines the mode of the block and provides a control signal to the switch (626) based on the mode. For example, if the mode is intra-mode, the general-purpose controller (621) controls the switch (626) to select intra-mode results for use by the residual calculator (623) and controls the entropy encoder (625) to select intra-prediction information and include the intra-prediction information in the bitstream. If the mode is inter-mode, the general-purpose controller (621) controls the switch (626) to select inter-prediction results for use by the residual calculator (623) and controls the entropy encoder (625) to select inter-prediction information and include the inter-prediction information in the bitstream.

[0085] The residual calculator (623) is configured to calculate the difference (residual data) between the received block and a prediction result selected from the intra-encoder (622) or the inter-encoder (630). The residual encoder (624) is configured to operate on the residual data to encode the residual data and generate transform coefficients. In one example, the residual encoder (624) is configured to transform the residual data from the spatial domain to the frequency domain to generate transform coefficients. The transform coefficients then undergo a quantization process to obtain quantized transform coefficients. In various embodiments, the video encoder (603) also includes a residual decoder (628). The residual decoder (628) is configured to perform an inverse transform to generate decoded residual data. The decoded residual data may be used by the intra-encoder (622) and the inter-encoder (630) as appropriate. For example, the inter-encoder (630) can generate decoded blocks based on the decoded residual data and inter-prediction information, and the intra-encoder (622) can generate decoded blocks based on the decoded residual data and intra-prediction information. In some examples, the decoded blocks are appropriately processed to generate decoded pictures, which may be buffered in a memory circuit (not shown) and used as reference pictures.

[0086] The entropy encoder (625) is configured to format a bitstream to include the encoded block. The entropy encoder (625) is configured to include various information in accordance with an appropriate standard, such as HEVC. In one example, the entropy encoder (625) is configured to include general control data, selected prediction information (e.g., intra-prediction information or inter-prediction information), residual information, and other appropriate information in the bitstream. Note that, according to the disclosed subject matter, when coding a block in a merged sub-mode of either an inter mode or a bi-prediction mode, residual information is not present.

[0087] 7 shows a diagram of a video decoder (710) according to another embodiment of the present disclosure. The video decoder (710) is configured to receive coded pictures that are part of a coded video sequence and decode the coded pictures to generate reconstructed pictures. In one example, the video decoder (710) is used in place of the video decoder (310) of the example of FIG. 3.

[0088] In the example of Figure 7, the video decoder (710) includes an entropy decoder (771), an inter-decoder (780), a residual decoder (773), a reconstruction module (774), and an intra-decoder (772), which are connected to each other as shown in Figure 7.

[0089] The entropy decoder (771) may be configured to reconstruct, from a coded picture, certain symbols that represent the syntax elements of which the coded picture is composed. Such symbols may include, for example, the mode in which the block is coded (e.g., intra mode, inter mode, bi-predictive mode, etc., the latter two being merged or other submodes), prediction information (e.g., intra-prediction information or inter-prediction information), which may identify certain samples or metadata used for prediction by the intra decoder (772) or inter decoder (780), respectively, and residual information, for example in the form of quantized transform coefficients. In one example, if the prediction mode is an inter mode or bi-predictive mode, the inter-prediction information is provided to the inter decoder (780), and if the prediction type is an intra-prediction type, the intra-prediction information is provided to the intra decoder (772). The residual information may be dequantized and provided to the residual decoder (773).

[0090] The inter decoder (780) is configured to receive inter prediction information and generate inter prediction results based on the inter prediction information.

[0091] The intra decoder (772) is configured to receive intra prediction information and generate a prediction result based on the intra prediction information.

[0092] The residual decoder (773) is configured to perform inverse quantization to extract dequantized transform coefficients and process the dequantized transform coefficients to transform the residual from the frequency domain to the spatial domain. The residual decoder (773) may also require certain control information (to include quantizer parameters (QP)), which may be provided by the entropy decoder (771) (the data path not shown in this way may be low volume control information only).

[0093] The reconstruction module (774) is configured to combine, in the spatial domain, the residual output by the residual decoder (773) with a prediction result (possibly output by an inter-prediction module or an intra-prediction module) to form a reconstructed block, which may be part of a reconstructed picture and, therefore, part of a reconstructed video. It should be noted that other appropriate operations, such as a deblocking operation, may be performed to improve visual quality.

[0094] It should be noted that the video encoders (303), (503), and (603) and the video decoders (310), (410), and (710) may be implemented using any suitable technology. In one embodiment, the video encoders (303), (503), and (603) and the video decoders (310), (410), and (710) may be implemented using one or more integrated circuits. In another embodiment, the video encoders (303), (503), and (603) and the video decoders (310), (410), and (710) may be implemented using one or more processors executing software instructions.

[0095] II. Machine video coding Videos or images can be consumed by humans for a variety of purposes, such as entertainment, education, etc. For this reason, video or image coding often exploits the characteristics of the human visual system to improve compression efficiency while maintaining high subjective quality.

[0096] In recent years, with the increase in machine learning applications, many intelligent platforms equipped with abundant sensors utilize video or images for machine vision tasks such as object detection, segmentation, or tracking. How to encode video or images for consumption by machine vision tasks can be an interesting and challenging problem. This has led to the introduction of research into video coding for machines (VCM). To this end, the international standards group MPEG created the Ad-Hoc group "Video Coding for Machines (VCM)" to standardize related technologies for better interoperability between different devices.

[0097] 8 illustrates an exemplary VCM architecture according to one embodiment of the present disclosure. Note that the output of the video decoding module in FIG. 8 is primarily for machine consumption, i.e., machine vision. However, in some cases, the output of the video decoding module can also be used for human vision, as shown in FIG. 8. Additionally, the exemplary VCM architecture may include an interface for a neural network (NN) module.

[0098] A video coding machine system from the client (or decoder) side may typically first perform video decoding to obtain a video sequence in a sample domain. Then, one or more machine tasks may be executed to understand the video content of the video sequence. In some cases, the output of the one or more machine tasks may be labeling information of a target object, for example, in the form of a rectangular bounding box in a decoded image or video sequence.

[0099] III. Versatile Video Coding VVC was recently jointly developed by two international standardization organizations, ITU and ISO / IEC. A version of VVC was finalized in July 2020 and is one of the most advanced video coding standards.

[0100] 9 illustrates an exemplary VVC encoder according to one embodiment of the present disclosure. The VVC encoder includes a transform and quantization (TR+Q) module, an entropy coding module, a motion estimation (ME) module, and a decoder. The decoder includes an inverse transform and inverse quantization (iTR+iQ) module, an intra prediction module, an inter prediction module, a synthesis prediction module, a deblocking filter (Deblk) module, a sample adaptive offset filter (SAO) module, an adaptive loop filter (ALF) module, and a buffer. The encoder receives coding blocks (CB) of an input picture and outputs a coded bitstream and a reconstructed picture. Both the transform and quantization module and the inverse transform and inverse quantization module process transform blocks (TB). Both the intra prediction module and the intra prediction module process PB. The synthesis prediction module combines inter prediction and intra prediction.

[0101] For intra prediction, various coding tools can be included, such as cross-component linear mode (CCLM), multiple reference line prediction (MRLP), intra sub-partitioning (ISP), matrix based intra prediction (MIP), etc.

[0102] For inter prediction, a set of coding tools may be included, such as affine motion model (AFFINE), subblock-based temporal merging candidates (SbTMC), adaptive motion vector resolution (AMVR), geometric partition mode (GPM), combined intra / inter prediction (CIIP), merge mode with motion vector difference (MMVD), bi-predictive with CU weights (BCW), decoder motion vector refinement (DMVR), bi-directional optical flow (BDOF), and prediction refinement using optical flow (PROF).

[0103] Other tools may be included, such as transforms, quantization, and in-loop filters, such as dependent quantization (DQ), multiple transform set (MTS), low frequency non-separable transform (LFNST), luma mapping and chroma scaling (LMCS), cross-component adaptive loop filter (CCALF), adaptive loop filter (ALF), sample adaptive offset filter (SAO), deblocking filter (Deblk), etc.

[0104] In a video coding system, some useful information that is not necessary for correctly decoding a video bitstream may be delivered, such as through one or more supplemental enhancement information (SEI) messages. A decoder may, for example, ignore such information. Alternatively, a decoder may decode the SEI messages for use after decoding a video sequence. In one example, virtual reality (VR) 360-degree video streaming may pack omnidirectional video into 2D conventional video for compression and transmission. After decoding the 2D video, the system may need to process the packed 2D video through servo processing steps before the video can be viewed in a 3D format. For example, the packed 2D video may be transformed back to the spherical domain according to a packing format such as equi-rectangular projection (ERP), cube-map projection (CMP), etc., to display a spherical signal with a hypothesized center view containing the most relevant information of the video content. These steps are not related to correctly decoding the video itself, but are useful for displaying the video content. Information such as packing method (ERP, CMP, etc.) or recommended view-centric information for 360-degree video can be transmitted via SEI messages. By receiving the information, the VR client system can efficiently process the decoded video content.

[0105] IV. Signaling Object Labeling Information In some related video coding standards, such as H.264, HEVC, or the recently completed VVC standard, an input video signal (or sequence) is treated as a waveform without any understanding of the meaning of the video content, such as how many people or objects are in the video or how they move around. On the other hand, machine vision tasks such as object detection, segmentation, or tracking can be designed to understand these types of information from video sequences. After decoding the video sequence, the client (or decoder) side can perform machine tasks to obtain labeling information of target objects in the image or video sequence.

[0106] Executing machine tasks on the client (or decoder) side can incur not only computational costs but also time costs to obtain the results of the machine tasks. In some systems, these costs (e.g., computational and time costs) are undesirable.

[0107] The present disclosure includes a method for transmitting detection or recognition information, such as labeling results, to a client (or decoder) side. Note that the method included in the present disclosure is not limited to the VVC standard. The principles of the method may also be applied to other video coding standards, such as H.264, HEVC, or AV1, developed by the Alliance for Open Media.

[0108] According to aspects of the present disclosure, labeling information, such as one or more bounding boxes, classes, and / or indices of objects for machine vision targets, may be determined at the encoder side rather than being determined at the decoder side after decoding the coded video bitstream. The determined labeling information may be coded and transmitted to the decoder and / or client side in various ways. After decoding the labeling information, the labeling results may be directly applied to the decoded image or video sequence without further machine task execution to understand the video content. In one example, each of the one or more bounding boxes may be applied to a different target object in the decoded image. In another example, the class and / or index of each target object may be displayed in the decoded image. In this manner, machine tasks may be performed independently of the picture resolution.

[0109] In one embodiment, the encoder system may apply a similar machine vision task module, such as the module shown in Figure 9, to obtain the associated labeling information, or may use a different one. For example, the output of the machine vision task may be in the form of a set of bounding boxes for each picture. Each bounding box may be represented by its position and size information.

[0110] According to aspects of the present disclosure, labeling information, such as information about the bounding boxes of objects in each picture, may be delivered by some side information messages in the coded video bitstream. For example, the labeling information may be transmitted via an SEI message in the coded video bitstream. In another embodiment, the labeling information may also be provided separately, such as in a separate file or plug-in file associated with the coded video bitstream.

[0111] In some embodiments, the labeling information includes location information of one or more bounding boxes within each picture. Various reference points and / or size information can be used to indicate the location of the bounding boxes. In one embodiment, the location information of the bounding boxes may include the top-left position of the bounding box and the size of the bounding box.

[0112] Table 1 shows an example syntax table that may be used to signal labeling information including location information of a bounding box within the current picture.

[0113] [Table 1]

[0114] In Table 1, the syntax element num_boxes indicates the total number of bounding boxes in the current picture. The syntax element box_loc_x[i] indicates the horizontal position of the top-left corner of the i-th bounding box relative to the top-left corner of the current picture in luma samples. The syntax element box_loc_y[i] indicates the vertical position of the top-left corner of the i-th bounding box relative to the top-left corner of the current picture in luma samples. The syntax element box_width[i] indicates the width of the i-th bounding box in luma samples. The syntax element box_height[i] indicates the height of the i-th bounding box in luma samples.

[0115] Note that the bounding box expression is not limited to the above format (top left position + size). For example, the top left position + bottom right position can also represent the bounding box.

[0116] Also, note that the location of the bounding box may be represented by any fixed location of the box. The top left corner is an example, and other locations may be used. For example, the center location of the bounding box, as well as the width and height of the bounding box, may be used to represent the bounding box.

[0117] In one embodiment, the labeling information may include category information of each object in the current picture. The category information indicates the category to which the object in the bounding box belongs. For example, the category may be person, car, airplane, etc. Table 2 shows an exemplary syntax table that may be used to signal labeling information including position information of the bounding box in the current picture and category information of the object in the current picture.

[0118] [Table 2]

[0119] In Table 2, the syntax element num_boxes indicates the total number of bounding boxes in the current picture. The syntax element category_id indicates the category to which the object in the i-th boundary belongs. The syntax element box_loc_x[i] indicates the horizontal position of the top-left corner of the i-th bounding box relative to the top-left corner of the current picture in luma samples. The syntax element box_loc_y[i] indicates the vertical position of the top-left corner of the i-th bounding box relative to the top-left corner of the current picture in luma samples. The syntax element box_width[i] indicates the width of the i-th bounding box in luma samples. The syntax element box_height[i] indicates the height of the i-th bounding box in luma samples.

[0120] In one embodiment, in addition to category information, the labeling information may include identification information of one or more objects in the current picture. In one example, the labeling information may include identification information for each object in the current picture. The identification information may be used to identify an object in a video sequence. For example, in object tracking, the identification information may be used to represent the same object in a video sequence. Table 3 shows a syntax table used to signal labeling information including position information of a bounding box in the current picture and category information and identification information of an object in the current picture.

[0121] [Table 3]

[0122] In Table 3, the syntax element num_boxes indicates the total number of bounding boxes in the current picture. The syntax element category_id indicates the category to which the object in the i-th boundary belongs. The syntax element instance_id indicates the identification number of the object in the i-th boundary. The syntax element box_loc_x[i] indicates the horizontal position of the top-left corner of the i-th bounding box relative to the top-left corner of the current picture in luma samples. The syntax element box_loc_y[i] indicates the vertical position of the top-left corner of the i-th bounding box relative to the top-left corner of the current picture in luma samples. The syntax element box_width[i] indicates the width of the i-th bounding box in luma samples. The syntax element box_height[i] indicates the height of the i-th bounding box in luma samples.

[0123] In some machine vision tasks, such as object tracking-related tasks, each object may appear in a different picture. To facilitate signaling the same bounding box across different pictures, the same bounding box ID may be used to represent the same object. In subsequent pictures, the absolute position and size of the bounding box may be signaled. In another embodiment, the relative change to its previous value in the previous picture may be used instead. Table 4 shows an exemplary syntax table that may be used to signal labeling information including position offset information of a bounding box in a current picture. In Table 4, the bounding box in the current picture is described by signaling the upper left corner position and the lower right corner position of the bounding box.

[0124] [Table 4]

[0125] In Table 4, the syntax element num_boxes indicates the total number of bounding boxes in the current picture. The syntax element sign_tl_x[i] indicates the sign of the difference in the horizontal top-left corner position of the i-th bounding box relative to the same bounding box in the previous picture, in luma samples. The syntax element sign_tl_y[i] indicates the sign of the difference in the vertical top-left corner position of the i-th bounding box relative to the same bounding box in the previous picture, in luma samples. The syntax element sign_br_x[i] indicates the sign of the difference in the horizontal bottom-right corner position of the i-th bounding box relative to the same bounding box in the previous picture, in luma samples. The syntax element sign_br_y[i] indicates the sign of the difference in the vertical bottom-right corner position of the i-th bounding box relative to the same bounding box in the previous picture, in luma samples. The syntax element delta_box_tl_loc_x[i] indicates the absolute value of the difference in the horizontal top-left corner position of the i-th bounding box relative to the same bounding box in the previous picture, in luma samples. The syntax element delta_box_tl_loc_y[i] indicates the absolute value of the difference in the vertical top-left corner position of the i-th bounding box relative to the same bounding box in the previous picture, in luma samples. The syntax element delta_box_br_loc_x[i] indicates the absolute value of the difference in the horizontal bottom-right corner position of the i-th bounding box relative to the same bounding box in the previous picture, in luma samples. The syntax element delta_box_br_loc_y[i] indicates the absolute value of the difference in the vertical bottom-right corner position of the i-th bounding box relative to the same bounding box in the previous picture, in luma samples.

[0126] The syntax elements sign_tl_x[i], sign_tl_y[i], sign_br_x[i], sign_br_y[i] may be set equal to 0 if there is no previous picture before the current picture. Alternatively, these syntax elements may be conditionally signaled only if there is a previous picture relative to the current picture in decoding or display order. If not signaled, these syntax elements may be inferred to be 0.

[0127] The variable PrevTopLeftBoxX[i] denotes the horizontal top-left corner location of the i-th bounding box in the previous picture that precedes the current picture in decoding or display order. The variable TopLeftBoxX[i] denotes the horizontal top-left corner location of the i-th bounding box in the current picture.

[0128] TopLeftBoxX[i]=PrevTopLeftBoxX[i]+sign_tl_x[i] * delta_box_tl_loc_x[i]

[0129] The variable PrevTopLeftBoxY[i] denotes the vertical position of the top-left corner of the i-th bounding box in the previous picture that precedes the current picture in decoding or display order. The variable TopLeftBoxY[i] denotes the vertical position of the top-left corner of the i-th bounding box in the current picture.

[0130] TopLeftBoxY[i]=PrevTopLeftBoxY[i]+sign_tl_y[i] * delta_box_tl_loc_y[i]

[0131] The variable PrevBotRightBoxX[i] denotes the location of the bottom right corner of the horizontal bounding box of the previous picture, which precedes the current picture in decoding or display order. The variable BotRightBoxX[i] denotes the location of the bottom right corner of the horizontal bounding box of the current picture.

[0132] BotRightBoxX[i]=PrevBotRightBoxX[i]+sign_br_x[i] * delta_box_br_loc_x[i]

[0133] The variable PrevBotRightBoxY[i] denotes the position of the bottom right vertical corner of the i-th bounding box in the previous picture that precedes the current picture in decoding or display order. The variable BotRightBoxY[i] denotes the position of the bottom right vertical corner of the i-th bounding box in the current picture.

[0134] BotRightBoxY[i]=PrevBotRightBoxY[i]+sign_br_y[i] * delta_box_br_loc_y[i]

[0135] If there is no previous picture before the current picture, the variables PrevTopLeftBoxX[i], PrevTopLeftBoxY[i], PrevBotRightBoxX[i], and PrevBotRightBoxY[i] may be initialized as 0.

[0136] After decoding or display of the current picture is complete, the variables PrevTopLeftBoxX[i], PrevTopLeftBoxY[i], PrevBotRightBoxX[i], and PrevBotRightBoxY[i] may be set equal to TopLeftBoxX[i], TopLeftBoxY[i], BotRightBoxX[i], and BotRightBoxY[i], respectively.

[0137] In one embodiment, the signaled syntax structure is similar to the syntax table above, but a bounding box in the current picture may be described by signaling its top-left corner position plus its width and height. In this case, the signaled delta values ​​may be the delta value of the top-left corner position of the i-th bounding box, the delta values ​​of the width and height of the i-th bounding box, and their respective code values.

[0138] In one embodiment, the object's category information (eg, category_id) and / or identification information (eg, instance_id) may be included in Table 4.

[0139] According to aspects of the present disclosure, the top-left and bottom-right positions of the bounding box may be located within the current picture. However, in some cases, when an object is no longer displayed in the current picture, the bounding box should no longer be displayed in the current picture. In one embodiment, for the i-th bounding box not shown in the current picture, a predetermined position value, such as a position value outside the picture boundary, may be used. For example, if the picture size is 1920 x 1080, the top-left and bottom-right positions of the bounding box may be set to 2000 (greater than the width and height of the picture) to indicate that the object is not present in the current picture and that the bounding box of the object does not need to be displayed.

[0140] According to aspects of the present disclosure, besides being included in metadata information (e.g., SEI messages) of the coded video bitstream, the labeling information may be included in a metadata file (e.g., a plug-in file) separate from the coded video bitstream. The labeling information may be considered as metadata information and may be delivered to the decoder and / or client side via system layer approaches such as real-time transport protocol (RTP), ISO Base Media Format files, and dynamic adaptive streaming over hypertext transport protocol (DASH).

[0141] The client (or decoder) side may request such information from the system layer to enable the labeling information in the decoded picture, if necessary.

[0142] In one embodiment, the client (or decoder) side may send a request message to the encoder side to request labeling information from the system layer.

[0143] In one embodiment, the client (or decoder) side may receive the labeling information from the encoder side without sending a request message.

[0144] In one embodiment, the client may send a request message to the decoder to validate the labeling information in the decoded picture.

[0145] In one embodiment, the decoder may validate the labeling information in the decoder picture without receiving a request message from the client.

[0146] V. Flowchart 10 shows a flowchart outlining an exemplary process (1000) according to one embodiment of the present disclosure. In various embodiments, the process (1000) is performed by processing circuitry such as processing circuitry within the terminal devices (210), (220), (230), and (240), a processing circuitry performing the functions of the video encoder (303), a processing circuitry performing the functions of the video decoder (310), a processing circuitry performing the functions of the video decoder (410), a processing circuitry performing the functions of the intra prediction module (452), a processing circuitry performing the functions of the video encoder (503), a processing circuitry performing the functions of the predictor (535), a processing circuitry performing the functions of the intra encoder (622), and a processing circuitry performing the functions of the intra decoder (772). In some embodiments, the process (1000) is implemented in software instructions, and thus, when the processing circuitry executes the software instructions, the processing circuitry performs the process (1000).

[0147] The process (1000) generally begins at step (S1010), where the process (1000) receives metadata associated with a coded video bitstream. The metadata includes labeling information for one or more objects detected in a first picture coded in the coded video bitstream. The process (1000) then proceeds to step (S1020).

[0148] In step S1020, the process (1000) decodes labeling information of one or more objects in a first picture coded in a coded video bitstream. Then, the process (1000) proceeds to step S1030.

[0149] The process (1000) applies the labeling information to one or more objects in the first picture in step (S1030), and then ends.

[0150] In one example, a bounding box may be applied to the detected object in the first picture. In another example, the category to which the detected object belongs may be displayed in the first picture. In another example, an identification number of the detected object may be displayed in the first picture.

[0151] In one embodiment, the metadata is included in an SEI message within the coded video bitstream.

[0152] In one embodiment, the metadata is contained in a separate file from the coded video bitstream.

[0153] In one embodiment, the labeling information indicates the total number of bounding boxes in the first picture and includes position information and size information for each bounding box, each bounding box being associated with one object of the one or more objects in the first picture.

[0154] In one embodiment, the labeling information includes category information indicating a category for each of the one or more objects.

[0155] In one embodiment, the labeling information includes identification information that identifies each of the one or more objects in the video sequence.

[0156] In one embodiment, the position information of one of the bounding boxes includes a position offset of the one of the bounding boxes between the first picture and a second picture coded in the video bitstream.

[0157] In one embodiment, the position information for one of the bounding boxes indicates a position outside the first picture relative to one of the bounding boxes based on an object associated with the one of the bounding boxes that is not present in the first picture.

[0158] In one embodiment, the process (1000) sends a request to receive metadata associated with a coded video bitstream.

[0159] VI. Computer Systems The techniques described above may be implemented as computer software using computer-readable instructions and physically stored on one or more computer-readable media. For example, Figure 11 illustrates a computer system (1100) suitable for implementing certain embodiments of the disclosed subject matter.

[0160] Computer software may be coded using any suitable machine code or computer language that can be subjected to assembly, compilation, linking, or similar mechanisms to generate code containing instructions that can be executed by one or more computer central processing units (CPUs) and graphics processing units (GPUs), etc., directly, or through interpretation and execution of microcode, etc.

[0161] The instructions may be executed by various types of computers or components thereof, including, for example, personal computers, tablet computers, servers, smartphones, gaming devices, Internet of Things devices, and the like.

[0162] 11 for computer system (1100) are exemplary in nature and are not intended to suggest any limitation as to the scope of use or functionality of the computer software implementing embodiments of the present disclosure, nor should the arrangement of components be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary embodiment of computer system (1100).

[0163] The computer system (1100) may include certain human interface input devices. Such human interface input devices may respond to input by one or more human users through, for example, tactile input (e.g., keystrokes, swipes, data glove movements), audio input (e.g., voice, clapping), visual input (e.g., gestures), or olfactory input (not shown). The human interface devices may be used to capture certain media that do not necessarily involve direct conscious human input, such as audio (e.g., speech, music, ambient sounds), images (e.g., scanned images, photographic images obtained from a still image camera), and video (e.g., two-dimensional video, three-dimensional video, including stereoscopic video).

[0164] The input human interface devices may include one or more of a keyboard (1101), a mouse (1102), a trackpad (1103), a touchscreen (1110), a data glove (not shown), a joystick (1105), a microphone (1106), a scanner (1107), and a camera (1108) (only one of each is shown).

[0165] The computer system (1100) may also include certain human interface output devices. Such human interface output devices may stimulate one or more of a human user's senses, for example, through tactile output, sound, light, and smell / taste. Such human interface output devices may include haptic output devices (e.g., haptic feedback via a touchscreen (1110), data gloves (not shown), or joystick (1105), although some haptic feedback devices may not function as input devices), audio output devices (such as speakers (1109), headphones (not shown)), visual output devices (such as screens (1110), including CRT screens, LCD screens, plasma screens, and OLED screens, each with or without touchscreen input capabilities and with or without haptic feedback capabilities, some of which may output two-dimensional visual output or three- or more-dimensional output by means of stereoscopic output, virtual reality glasses (not shown), holographic displays, smoke tanks (not shown)), and printers (not shown). These visual output devices (such as a screen 1110 ) may be connected to the system bus 1148 via a graphics adapter 1150 .

[0166] The computer system (1100) may also include human-accessible storage devices and associated media such as optical media including CD / DVD ROM / RW (1120) with media such as CD / DVD (1121), thumb drives (1122), removable hard drives or solid state drives (1123), legacy magnetic media such as tape and floppy disks (not shown), and specialized ROM / ASIC / PLD-based devices such as security dongles (not shown).

[0167] Those skilled in the art will also understand that the term "computer-readable medium" as used in connection with the presently disclosed subject matter does not encompass transmission media, carrier waves, or other transitory signals.

[0168] The computer system (1100) may also include a network interface (1154) to one or more communication networks (1155). The one or more communication networks (1155) may be, for example, wireless, wired, or optical. The one or more communication networks (1155) may further be local, wide-area, metropolitan, vehicular and industrial, real-time, and delay-tolerant, etc. Examples of the one or more communication networks (1155) include local area networks such as Ethernet and wireless LAN; cellular networks including GSM, 3G, 4G, 5G, LTE, etc.; wired or wireless TV wide-area digital networks including cable TV, satellite TV, and terrestrial broadcast TV; and vehicular and industrial networks including CANBus. Certain networks typically require an external network interface adapter connected to a particular general-purpose data port or peripheral bus 1149 (e.g., a USB port on the computer system 1100), while others are generally integrated into the core of the computer system 1100 by connecting to the system bus, as described below (e.g., an Ethernet interface for a PC computer system or a cellular network interface for a smartphone computer system). Using any of these networks, the computer system 1100 may communicate with other entities. Such communication may be unidirectional, receive-only (e.g., television broadcast), unidirectional transmit-only (e.g., from a CANbus to a particular CANbus device), or bidirectional, e.g., to other computer systems using local or wide-area digital networks. Specific protocols and protocol stacks may be used with each of these networks and network interfaces, as described above.

[0169] The aforementioned human interface devices, human-accessible storage devices, and network interfaces may be attached to the core (1140) of the computer system (1100).

[0170] The cores (1140) may include one or more central processing units (CPUs) (1141), graphics processing units (GPUs) (1142), dedicated programmable processing units in the form of field programmable gate areas (FPGAs) (1143), task-specific hardware accelerators (1144), and graphics adapters (1150). These devices, along with read-only memory (ROM) (1145), random access memory (1146), and internal mass storage devices (1147) such as non-user-accessible internal hard drives and SSDs, may be connected via a system bus (1148). In some computer systems, the system bus (1148) may be accessible in the form of one or more physical plugs to allow expansion with additional CPUs, GPUs, and the like. Peripheral devices may be connected directly to the core's system bus (1148) or via a peripheral bus (1149). In one example, a screen (1110) may be connected to the graphics adapter (1150). Peripheral bus architectures include PCI, USB, and the like.

[0171] The CPU (1141), GPU (1142), FPGA (1143), and accelerator (1144) may execute specific instructions that, in combination, may constitute the aforementioned computer code. That computer code may be stored in ROM (1145) or RAM (1146). Transient data may be stored in RAM (1146), while persistent data may be stored in, for example, internal mass storage device (1147). Rapid storage and retrieval from any of the memory devices may be enabled through the use of cache memory closely associated with one or more of the CPU (1141), GPU (1142), mass storage device (1147), ROM (1145), RAM (1146), etc.

[0172] The computer-readable medium may bear computer code for performing various computer-implemented operations. The medium and computer code may be those specially designed and constructed for the purposes of the present disclosure, or they may be of the kind well known and available to those skilled in the computer software arts.

[0173] As an example, but not by way of limitation, a computer system (1100) having an architecture, and specifically the core (1140), may provide functionality as a result of a processor (including a CPU, GPU, FPGA, accelerator, etc.) executing software embodied in one or more tangible computer-readable media. Such computer-readable media may be media associated with the user-accessible mass storage devices introduced above, as well as specific storage of the core (1140) that is non-transitory in nature, such as the core's internal mass storage device (1147) or ROM (1145). Software implementing various embodiments of the present disclosure may be stored in such devices and executed by the core (1140). The computer-readable media may include one or more memory devices or chips, depending on particular needs. The software may cause the core (1140) and specifically the processor (including a CPU, GPU, FPGA, etc.) therein to perform particular processes, or particular portions of particular processes, described herein, including defining data structures stored in RAM (1146) and modifying such data structures according to the software-defined processes. Additionally, or alternatively, a computer system may provide functionality as a result of logic hardwired or otherwise embodied in circuitry (e.g., accelerator (1144)), which may operate in place of or in conjunction with software to perform particular processes or portions of particular processes described herein. Where appropriate, references to software may include logic, and vice versa. Where appropriate, references to computer-readable media may encompass circuitry (such as an integrated circuit (IC)) that stores software for execution, circuitry that embodies logic for execution, or both. The present disclosure encompasses any suitable combination of hardware and software.

[0174] While this disclosure has described several exemplary embodiments, there are modifications, substitutions, and various substitute equivalents that fall within the scope of this disclosure. It will thus be appreciated that those skilled in the art can devise numerous systems and methods that, although not explicitly shown or described herein, embody the principles of the present disclosure and are therefore within its spirit and scope.

[0175] Appendix A: Acronyms ALF: Adaptive Loop Filter AMVP: Advanced Motion Vector Prediction APS: Adaptation Parameter Set ASIC: Application-Specific Integrated Circuit ATMVP: Alternative / Advanced Temporal Motion Vector Prediction AV1:AOMedia Video 1 AV2:AOMedia Video 2 BMS: Benchmark Set BV: Block Vector CANBus: Controller Area Network Bus CB: Coding Block CC-ALF: Cross-Component Adaptive Loop Filter CD: Compact Disc CDEF: Constrained Directional Enhancement Filter CPR: Current Picture Referencing CPU: Central Processing Unit CRT: Cathode Ray Tube CTB: Coding Tree Block CTU: Coding Tree Unit CU: Coding Unit DPB: Decoder Picture Buffer DPCM: Differential Pulse-Code Modulation DPS: Decoding Parameter Set DVD: Digital Video Disc FPGA: Field Programmable Gate Area JCCR: Joint CbCr Residual Coding JVET: Joint Video Exploration Team GOP: Group of Pictures GPU: Graphics Processing Unit GSM: Global System for Mobile communication HDR: High Dynamic Range HEVC: High Efficiency Video Coding HRD: Hypothetical Reference Decoder IBC: Intra Block Copy IC: Integrated Circuit ISP: Intra Sub-Partitions JEM: Joint Exploration Model LAN: Local Area Network LCD: Liquid-Crystal Display LR: Loop Restoration Filter LRU: Loop Restoration Unit LTE: Long-Term Evolution MPM: Most Probable Mode MV: Motion Vector OLED: Organic Light-Emitting Diode PB: Prediction Block PCI: Peripheral Component Interconnect PDPC: Position Dependent Prediction Combination PLD: Programmable Logic Device PPS: Picture Parameter Set PU: Prediction Unit RAM: Random Access Memory ROM: Read-Only Memory SAO: Sample Adaptive Offset SCC: Screen Content Coding SDR: Standard Dynamic Range SEI: Supplementary Enhancement Information SNR: Signal-to-Noise Ratio SPS: Sequence Parameter Set SSD: Solid-state drive TU: Transform Unit USB: Universal Serial Bus VPS: Video Parameter Set VUI: Video Usability Information VVC: Versatile Video Coding WAIP: Wide-Angle Intra Prediction [Explanation of symbols]

[0176] 200 Communication Systems 210,220,230,240 Terminal Devices 250 Network 301 Video Sources 302 Video Picture Stream 303 Video Encoder 304 encoded video data 305 Streaming Server 306 Client Subsystem 307 Copy of encoded video data 308 Client Subsystem 309 Copy of encoded video data 310 Video Decoder 311 Video Pictures 312 Display 313 Capture Subsystem 320 Electronic Devices 330 Electronic Devices 401 Channel 410 Video Decoder 412 Render Device 415 Buffer Memory 420 Entropy Decoder / Parser 421 Symbol 430 Electronic Devices 431 Receiver 451 Scaler / Descaler Unit 452 Intra-picture prediction unit 453 Motion Compensation Prediction Unit 455 Aggregator 456 Loop Filter Unit 457 Reference Picture Memory 458 Current Picture Buffer 501 Video Sources 503 Video Encoder 520 Electronic Devices 530 Source Coder 532 Coding Engine 533 Local Video Decoder 534 Reference Picture Memory 535 Predictor 540 Transmitter 543 Video Sequences 545 Entropy Coder 550 Controller 560 Communication Channels 603 Video Encoder 621 General-purpose controller 622 Intra Encoder 623 Residual Calculator 624 Residual Encoder 625 Entropy Encoder 626 Switch 628 Residual Decoder 630 Interencoder 710 Video Decoder 771 Entropy Decoder 772 Intra Decoder 773 Residual Decoder 774 Reconstruction Module 780 Interdecoder 1101 Keyboard 1102 Mouse 1103 Trackpad 1105 Joystick 1106 Microphone 1107 Scanner 1108 Camera 1110 Touchscreen 1120 CD / DVD ROM / RW 1121 Medium 1122 thumb drive 1123 Solid State Drive 1140 cores 1141 Central Processing Unit 1142 Graphics Processing Unit 1143 Field Programmable Gate Area 1144 Hardware Accelerator 1145 Read-Only Memory 1146 Random Access Memory 1147 Internal mass storage 1148 System Bus 1149 Peripheral Bus 1150 graphics adapter 1154 Network Interface 1155 Communication Network

Claims

1. A method of video decoding in a decoder, comprising: receiving metadata associated with a coded video bitstream, the metadata including labeling information of one or more objects detected in a first picture coded in the coded video bitstream, the labeling information including, for the one or more objects, position information including a position of a bounding box surrounding the object in the first picture and a predetermined position value outside a picture boundary of a second picture coded in the coded video bitstream, the value indicating that the bounding box is outside a picture boundary of the second picture and that the object is not shown in the second picture; decoding the labeling information of the one or more objects of the first picture coded in the coded video bitstream; applying the labeling information to the one or more objects in the first picture, wherein the objects are not shown in the second picture and the bounding boxes corresponding to the objects are not displayed in the second picture; A method comprising:

2. The method of claim 1, wherein the metadata is included in a supplemental enhancement information (SEI) message within the coded video bitstream.

3. The method of claim 1, wherein the metadata is contained in a file separate from the coded video bitstream.

4. The labeling information indicates a total number of bounding boxes in the first picture and includes position information and size information of each bounding box; The method of claim 1 , wherein each bounding box is associated with one object of the one or more objects in the first picture.

5. The method described in claim 1, wherein the labeling information includes object identification information, and a first object appearing in the first picture and another picture coded in the coded video bitstream has the same object identification information in both the first picture and the another picture.

6. The method described in claim 1, wherein the labeling information includes identification information that identifies each of the one or more objects in the video sequence.

7. The method described in claim 4, wherein the position information of one of the bounding boxes indicates a position offset of the one of the bounding boxes between the first picture and another picture coded in the coded video bitstream.

8. The method described in claim 1, wherein the labeling information includes position offset information of a bounding box, the position offset information indicating a difference in the relative position of the bounding box between the first picture and a second picture coded in the video bitstream.

9. The method of claim 1, further comprising the step of sending a request to receive the metadata associated with the coded video bitstream.

10. The method described in claim 1, wherein the labeling information includes category information including a category for each of the one or more objects.

11. A step of determining labeling information for one or more objects in a first picture to be encoded in a video bitstream, wherein the labeling information includes, for the one or more objects, position information including a position of a bounding box surrounding the object in the first picture and a value of a predetermined position outside the picture boundary of the second picture to indicate that the bounding box is outside the picture boundary of the second picture to be encoded in the video bitstream, to indicate that the object is not shown in the second picture; encoding metadata associated with the video bitstream, the metadata including the labeling information of the one or more objects in the first picture, the objects not being shown in the second picture, and the bounding boxes corresponding to the objects not being displayed in the second picture; A method comprising:

12. The method of claim 11, wherein the metadata is included in a supplemental enhancement information (SEI) message within the video bitstream.

13. The method of claim 11, wherein the metadata is contained in a file separate from the video bitstream.

14. The method described in claim 11, wherein the labeling information indicates the total number of bounding boxes in the first picture and includes position information and size information for each bounding box, and each bounding box is associated with one of the one or more objects in the first picture.

15. The method described in claim 11, wherein the labeling information includes object identification information, and a first object appearing in the first picture and another picture encoded in the video bitstream has the same object identification information in both the first picture and the another picture.

16. The method described in claim 11, wherein the labeling information includes identification information that identifies each of the one or more objects in the video sequence.

17. The method described in claim 14, wherein the position information of one of the bounding boxes indicates a position offset of the one of the bounding boxes between the first picture and another picture encoded in the video bitstream.

18. The method described in claim 11, wherein the labeling information includes position offset information of a bounding box, the position offset information indicating a difference in the relative position of the bounding box between the first picture and a second picture encoded in the video bitstream.

19. A method for processing visual media data, comprising: processing a video bitstream of the visual media data according to a formatting rule, the formatting rule comprising: the metadata associated with the video bitstream includes labeling information of one or more objects detected in a first picture coded in the video bitstream, the labeling information including, for one of the one or more objects, position information including a position of a bounding box surrounding the object in the first picture and a value of a predetermined position outside a picture boundary of a second picture coded in the video bitstream that indicates that the bounding box is outside a picture boundary of the second picture and the object is not shown in the second picture; the labeling information is applied to the one or more objects in the first picture; the object is not shown in the second picture and the bounding box corresponding to the object is not displayed in the second picture; How to identify that.

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