Intra TMP-LIC merge mode

Abstract

Systems, methods, and instrumentalities are disclosed herein for the field of video compression. In examples, a video decoder or video encoder may obtain a plurality of block vector-based merge predictor candidates for a current block. A predictor may be selected from the plurality of block vector-based merge predictor candidates. The video decoder or video encoder may determine whether local illumination compensation (LIC) is enabled for the current block based on the predictor. Based on a determination that LIC is enabled for the current block, a prediction block may be generated. Based on a determination that LIC is enabled for the current block, LIC parameters may be determined and the LIC parameters may be applied to the prediction block. The current block may be decoded or encoded based on the prediction block.

Description

INTRA TMP-LIC MERGE MODECROSS-REFERENCE TO RELATED APPLICATOINS

[0001] The application claims the benefit of European Patent Application Number 23307370.9, filed December 22, 2023, the contents of which are incorporated by reference in their entirety herein.BACKGROUND

[0002] Video coding systems may be used to compress digital video signals, e.g., to reduce the storage and / or transmission bandwidth needed for such signals. Video coding systems may include, for example, block-based, wavelet-based, and / or object-based systems.SUMMARY

[0003] Systems, methods, and instrumentalities are disclosed herein for the field of video compression.

[0004] In examples, a video decoder or video encoder may obtain a plurality of block vector-based merge predictor candidates for a current block. A predictor may be selected from the plurality of block vector-based merge predictor candidates. In examples, the block vector-based merge predictor candidates may be intra template matching (intraTM P) merge predictor candidates or may be intra block copy (IBC) merge predictor candidates. The video decoder or video encoder may determine whether local illumination compensation (LIC) is enabled for the current block based on the predictor. Based on a determination that LIC is enabled for the current block, a prediction block may be generated. The current block may be decoded or encoded based on the prediction block. In examples, the determination of whether LIC is enabled for the current block may be determined based on an LIC usage of the predictor. Based on a determination that LIC is enabled for the current block, LIC parameters may be determined and the LIC parameters may be applied to the prediction block. The current block may be decoded or encoded based on the LIC parameters and the predicted block.

[0005] In examples, an LIC model may be derived based on the predictor. The plurality of block vectorbased merge candidates may be refined based on the LIC model. The LIC parameters may be determined based on the LIC model. In examples, an encoder may refine a plurality of block vector-based merge predictor candidates based on the determination of LIC being enabled. The encoder may include an indication in video data that indicates that LIC is enabled for the current block based on the determination of LIC being enabled. In examples, a decoder may obtain an LIC indication that indicates that LIC is enabled.Based on the LIC indication, the decoder may determine that the LIC is enabled. The plurality of block vectorbased merge candidates may be refined based on the LIC indication. In examples, the video decoder or video encoder may sort the plurality of block vector-based merge predictor candidates based on a template matching cost to form a final ordered list of merge candidates. The predictor may be selected from the final ordered list of merge candidates.

[0006] These examples may be performed by a device with a processor. The device may be an encoder or a decoder. These examples may be performed by a computer program product which is stored on a non- transitory computer readable medium and includes program code instructions. These examples may be performed by a computer program comprising program code instructions.

[0007] Systems, methods, and instrumentalities described herein may involve a decoder. In some examples, the systems, methods, and instrumentalities described herein may involve an encoder. In some examples, the systems, methods, and instrumentalities described herein may involve a signal (e.g., from an encoder and / or received by a decoder). A computer-readable medium may include instructions for causing one or more processors to perform methods described herein. A computer program product may include instructions which, when the program is executed by one or more processors, may cause the one or more processors to carry out the methods described herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented.

[0009] FIG. 1 B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1A according to an embodiment.

[0010] FIG. 1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1A according to an embodiment.

[0011] FIG. 1 D is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1 A according to an embodiment.

[0012] FIG. 2 illustrates an example video encoder.

[0013] FIG. 3 illustrates an example video decoder.

[0014] FIG. 4 illustrates an example of a a system in which various aspects and examples may be implemented.

[0015] FIG. 5 illustrates an example of a current CTU processing order and its available reference samples in the current CTU and the left CTU.

[0016] FIG. 6 illustrates an example of padding candidates for the replacement of the zero-vector in the IBC list.

[0017] FIG. 7 illustrates an example of an extended reference region for IBC.

[0018] FIG. 8 illustrates an example of an intra template matching search area used.

[0019] FIG. 9 illustrates an example of a spatial part of a filter.

[0020] FIG. 10 illustrates an example of a reference area used to derive filter coefficients.

[0021] FIG. 11 illustrates an example of an intra TMP mode parsing process according to a combination of IntraTMP and LIC.

[0022] FIG. 12 illustrates an example of deriving a LIC indication based on a selected predictor (e.g., IntraTMP merge candidate).

[0023] FIG. 13 illustrates an example of deriving an LIC model based on a selected IntraTMP predictor (e.g., selected merge candidate).

[0024] FIG. 14 illustrates an example of derived an LIC mode based on a merge mechanism with explicit signaling of an LIC indication.

[0025] FIG. 15 illustrates an example of an indication that indicates if an inherited LIC indication is used for a current block.

[0026] FIG. 16 illustrates an example of intra TMP merge list construction according to an LIC indication value.DETAILED DESCRIPTION

[0027] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings.

[0028] FIG. 1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0029] As shown in FIG. 1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a ON 106 / 115, a public switched telephone network(PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a "station” and / or a "STA”, may be configured to transmit and / or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Pi device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE.

[0030] The communications systems 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or the other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a gNB, a NR NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0031] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

[0032] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0033] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink (DL) Packet Access (HSDPA) and / or High-Speed UL Packet Access (HSUPA).

[0034] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0035] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access , which may establish the air interface 116 using New Radio (NR).

[0036] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., a eNB and a gNB).

[0037] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0038] The base station 114b in FIG. 1A may be a wireless router, Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., foruse by drones), a roadway, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106 / 115.

[0039] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may be utilizing a NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0040] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or the other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0041] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with the base station 114a, which may employ acellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0042] FIG. 1 B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1 B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0043] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. As suggested above, the processor 118 may include a plurality of processors. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG. 1 B depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0044] The transmit / receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0045] Although the transmit / receive element 122 is depicted in FIG. 1 B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0046] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit / receive element 122 and to demodulate the signals that are received by the transmit / receive element122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11 , for example.

[0047] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and / or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0048] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium- ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0049] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable locationdetermination method while remaining consistent with an embodiment.

[0050] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and / or Augmented Reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer,a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0051] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the UL (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and / or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception)).

[0052] FIG. 1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0053] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a.

[0054] Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, and the like. As shown in FIG. 1 C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0055] The CN 106 shown in FIG. 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0056] The MME 162 may be connected to each of the eNode-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0057] The SGW 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via the S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter-eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0058] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0059] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0060] Although the WTRU is described in FIGS. 1A-1 D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0061] In representative embodiments, the other network 112 may be a WLAN.

[0062] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic in to and / or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and / or referred to as peer-to- peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.11e DLS or an 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an "ad-hoc” mode of communication.

[0063] When using the 802.11ac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example in in 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0064] High Throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.

[0065] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two noncontiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0066] Sub 1 GHz modes of operation are supported by 802.11 af and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802.11 af and 802.11ah relative to those used in 802.11n, and 802.11ac. 802.11af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11 ah may support Meter Type Control / Machine- Type Communications, such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0067] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11 n, 802.11 ac, 802.11 af, and 802.11 ah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by allSTAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.11 ah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0068] In the United States, the available frequency bands, which may be used by 802.11 ah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11 ah is 6 MHz to 26 MHz depending on the country code.

[0069] FIG. 1 D is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0070] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 108b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0071] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c usingsubframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[0072] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with / connect to gNBs 180a, 180b, 180c while also communicating with / connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.

[0073] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG. 1 D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0074] The CN 115 shown in FIG. 1 D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0075] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency(URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, and / or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0076] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet-based, and the like.

[0077] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0078] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0079] In view of Figures 1A-1 D, and the corresponding description of Figures 1A-1 D, one or more, or all, of the functions described herein with regard to one or more of: WTRU 102a-d, Base Station 114a-b, eNode- B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a- b, and / or any other device(s) described herein, may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0080] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and / or deployed aspart of a wired and / or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and / or may performing testing using over-the-air wireless communications.

[0081] The one or more emulation devices may perform the one or more, including all, functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0082] This application describes a variety of aspects, including tools, features, examples, models, approaches, etc. Many of these aspects are described with specificity and, at least to show the individual characteristics, are often described in a manner that may sound limiting. However, this is for purposes of clarity in description, and does not limit the application or scope of those aspects. Indeed, all of the different aspects may be combined and interchanged to provide further aspects. Moreover, the aspects may be combined and interchanged with aspects described in earlier filings as well.

[0083] The aspects described and contemplated in this application may be implemented in many different forms. FIGS. 5-16 described herein may provide some examples, but other examples are contemplated. The discussion of FIGS. 5-16 does not limit the breadth of the implementations. At least one of the aspects generally relates to video encoding and decoding, and at least one other aspect generally relates to transmitting a bitstream generated or encoded. These and other aspects may be implemented as a method, an apparatus, a computer readable storage medium having stored thereon instructions for encoding or decoding video data according to any of the methods described, and / or a computer readable storage medium having stored thereon a bitstream generated according to any of the methods described.

[0084] In the present application, the terms "reconstructed” and "decoded” may be used interchangeably, the terms "pixel” and "sample” may be used interchangeably, the terms "image,” "picture” and "frame” may be used interchangeably.

[0085] Various methods are described herein, and each of the methods comprises one or more steps or actions for achieving the described method. Unless a specific order of steps or actions is required for proper operation of the method, the order and / or use of specific steps and / or actions may be modified or combined. Additionally, terms such as "first”, "second”, etc. may be used in various examples to modify an element, component, step, operation, etc., such as, for example, a "first decoding” and a "second decoding”. Use ofsuch terms does not imply an ordering to the modified operations unless specifically required. So, in this example, the first decoding need not be performed before the second decoding, and may occur, for example, before, during, or in an overlapping time period with the second decoding.

[0086] Various methods and other aspects described in this application may be used to modify modules, for example, decoding modules, of a video encoder 200 and decoder 300 as shown in FIG. 2 and FIG. 3. Moreover, the subject matter disclosed herein may be applied, for example, to any type, format or version of video coding, whether described in a standard or a recommendation, whether pre-existing or future- developed, and extensions of any such standards and recommendations. Unless indicated otherwise, or technically precluded, the aspects described in this application may be used individually or in combination.

[0087] Various numeric values are used in examples described the present application, such as bits, bit depth, etc. These and other specific values are for purposes of describing examples and the aspects described are not limited to these specific values.

[0088] FIG. 2 is a diagram showing an example video encoder. Variations of example encoder 200 are contemplated, but the encoder 200 is described below for purposes of clarity without describing all expected variations.

[0089] Before being encoded, the video sequence may go through pre-encoding processing (201), for example, applying a color transform to the input color picture (e.g., conversion from RGB 4:4:4 to YCbCr 4:2:0), or performing a remapping of the input picture components in order to get a signal distribution more resilient to compression (for instance using a histogram equalization of one of the color components). Metadata may be associated with the pre-processing, and attached to the bitstream.

[0090] In the encoder 200, a picture is encoded by the encoder elements as described below. The picture to be encoded is partitioned (202) and processed in units of, for example, coding units (CUs). Each unit is encoded using, for example, either an intra or inter mode. When a unit is encoded in an intra mode, it performs intra prediction (260). In an inter mode, motion estimation (275) and compensation (270) are performed. The encoder decides (205) which one of the intra mode or inter mode to use for encoding the unit, and indicates the intra / inter decision by, for example, a prediction mode flag. Prediction residuals are calculated, for example, by subtracting (210) the predicted block from the original image block.

[0091] The prediction residuals are then transformed (225) and quantized (230). The quantized transform coefficients, as well as motion vectors and other syntax elements, are entropy coded (245) to output a bitstream. The encoder can skip the transform and apply quantization directly to the non-transformed residual signal. The encoder can bypass both transform and quantization, i.e., the residual is coded directly without the application of the transform or quantization processes.

[0092] The encoder decodes an encoded block to provide a reference for further predictions. The quantized transform coefficients are de-quantized (240) and inverse transformed (250) to decode predictionresiduals. Combining (255) the decoded prediction residuals and the predicted block, an image block is reconstructed. In-loop filters (265) are applied to the reconstructed picture to perform, for example, deblocking / SAO (Sample Adaptive Offset) filtering to reduce encoding artifacts. The filtered image is stored at a reference picture buffer (280).

[0093] FIG. 3 is a diagram showing an example of a video decoder. In example decoder 300, a bitstream is decoded by the decoder elements as described below. Video decoder 300 generally performs a decoding pass reciprocal to the encoding pass as described in FIG. 2. The encoder 200 also generally performs video decoding as part of encoding video data.

[0094] In particular, the input of the decoder includes a video bitstream, which may be generated by video encoder 200. The bitstream is first entropy decoded (330) to obtain transform coefficients, motion vectors, and other coded information. The picture partition information indicates how the picture is partitioned. The decoder may therefore divide (335) the picture according to the decoded picture partitioning information. The transform coefficients are de-quantized (340) and inverse transformed (350) to decode the prediction residuals. Combining (355) the decoded prediction residuals and the predicted block, an image block is reconstructed. The predicted block may be obtained (370) from intra prediction (360) or motion-compensated prediction (i.e., inter prediction) (375). In-loop filters (365) are applied to the reconstructed image. The filtered image is stored at a reference picture buffer (380).

[0095] The decoded picture can further go through post-decoding processing (385), for example, an inverse color transform (e.g. conversion from YCbCr 4:2:0 to RGB 4:4:4) or an inverse remapping performing the inverse of the remapping process performed in the pre-encoding processing (201). The post-decoding processing can use metadata derived in the pre-encoding processing and signaled in the bitstream. In an example, the decoded images (e.g., after application of the in-loop filters (365) and / or after post-decoding processing (385), if post-decoding processing is used) may be sent to a display device for rendering to a user.

[0096] FIG. 4 is a diagram showing an example of a system in which various aspects and examples described herein may be implemented. System 400 may be embodied as a device including the various components described below and is configured to perform one or more of the aspects described in this document. Examples of such devices, include, but are not limited to, various electronic devices such as personal computers, laptop computers, smartphones, tablet computers, digital multimedia set top boxes, digital television receivers, personal video recording systems, connected home appliances, and servers. Elements of system 400, singly or in combination, may be embodied in a single integrated circuit (IC), multiple ICs, and / or discrete components. For example, in at least one example, the processing and encoder / decoder elements of system 400 are distributed across multiple ICs and / or discrete components. In various examples, the system 400 is communicatively coupled to one or more other systems, or other electronicdevices, via, for example, a communications bus or through dedicated input and / or output ports. In various examples, the system 400 is configured to implement one or more of the aspects described in this document.

[0097] The system 400 includes at least one processor 410 configured to execute instructions loaded therein for implementing, for example, the various aspects described in this document. Processor 410 can include embedded memory, input output interface, and various other circuitries as known in the art. The system 400 includes at least one memory 420 (e.g., a volatile memory device, and / or a non-volatile memory device). System 400 includes a storage device 440, which can include non-volatile memory and / or volatile memory, including, but not limited to, Electrically Erasable Programmable Read-Only Memory (EEPROM), Read-Only Memory (ROM), Programmable Read-Only Memory (PROM), Random Access Memory (RAM), Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM), flash, magnetic disk drive, and / or optical disk drive. The storage device 440 can include an internal storage device, an attached storage device (including detachable and non-detachable storage devices), and / or a network accessible storage device, as non-limiting examples.

[0098] System 400 includes an encoder / decoder module 430 configured, for example, to process data to provide an encoded video or decoded video, and the encoder / decoder module 430 can include its own processor and memory. The encoder / decoder module 430 represents module(s) that may be included in a device to perform the encoding and / or decoding functions. As is known, a device can include one or both of the encoding and decoding modules. Additionally, encoder / decoder module 430 may be implemented as a separate element of system 400 or may be incorporated within processor 410 as a combination of hardware and software as known to those skilled in the art.

[0099] Program code to be loaded onto processor 410 or encoder / decoder 430 to perform the various aspects described in this document may be stored in storage device 440 and subsequently loaded onto memory 420 for execution by processor 410. In accordance with various examples, one or more of processor 410, memory 420, storage device 440, and encoder / decoder module 430 can store one or more of various items during the performance of the processes described in this document. Such stored items can include, but are not limited to, the input video, the decoded video or portions of the decoded video, the bitstream, matrices, variables, and intermediate or final results from the processing of equations, formulas, operations, and operational logic.

[0100] In some examples, memory inside of the processor 410 and / or the encoder / decoder module 430 is used to store instructions and to provide working memory for processing that is needed during encoding or decoding. In other examples, however, a memory external to the processing device (for example, the processing device may be either the processor 410 or the encoder / decoder module 430) is used for one or more of these functions. The external memory may be the memory 420 and / or the storage device 440, for example, a dynamic volatile memory and / or a non-volatile flash memory. In several examples, an externalnon-volatile flash memory is used to store the operating system of, for example, a television. In at least one example, a fast external dynamic volatile memory such as a RAM is used as working memory for video encoding and decoding operations.

[0101] The input to the elements of system 400 may be provided through various input devices as indicated in block 445. Such input devices include, but are not limited to, (i) a radio frequency (RF) portion that receives an RF signal transmitted, for example, over the air by a broadcaster, (ii) a Component (COMP) input terminal (or a set of COMP input terminals), (iii) a Universal Serial Bus (USB) input terminal, and / or (iv) a High Definition Multimedia Interface (HDMI) input terminal. Other examples, not shown in FIG. 4, include composite video.

[0102] In various examples, the input devices of block 445 have associated respective input processing elements as known in the art. For example, the RF portion may be associated with elements suitable for (i) selecting a desired frequency (also referred to as selecting a signal, or band-limiting a signal to a band of frequencies), (ii) downconverting the selected signal, (iii) band-limiting again to a narrower band of frequencies to select (for example) a signal frequency band which may be referred to as a channel in certain examples, (iv) demodulating the downconverted and band-limited signal, (v) performing error correction, and / or (vi) demultiplexing to select the desired stream of data packets. The RF portion of various examples includes one or more elements to perform these functions, for example, frequency selectors, signal selectors, band-limiters, channel selectors, filters, downconverters, demodulators, error correctors, and demultiplexers. The RF portion can include a tuner that performs various of these functions, including, for example, downconverting the received signal to a lower frequency (for example, an intermediate frequency or a nearbaseband frequency) or to baseband. In one set-top box example, the RF portion and its associated input processing element receives an RF signal transmitted over a wired (for example, cable) medium, and performs frequency selection by filtering, downconverting, and filtering again to a desired frequency band. Various examples rearrange the order of the above-described (and other) elements, remove some of these elements, and / or add other elements performing similar or different functions. Adding elements can include inserting elements in between existing elements, such as, for example, inserting amplifiers and an analog- to-digital converter. In various examples, the RF portion includes an antenna.

[0103] The USB and / or HDMI terminals can include respective interface processors for connecting system 400 to other electronic devices across USB and / or HDMI connections. It is to be understood that various aspects of input processing, for example, Reed-Solomon error correction, may be implemented, for example, within a separate input processing IC or within processor 410 as necessary. Similarly, aspects of USB or HDMI interface processing may be implemented within separate interface ICs or within processor 410 as necessary. The demodulated, error corrected, and demultiplexed stream is provided to various processing elements, including, for example, processor 410, and encoder / decoder 430 operating in combination withthe memory and storage elements to process the datastream as necessary for presentation on an output device.

[0104] Various elements of system 400 may be provided within an integrated housing, Within the integrated housing, the various elements may be interconnected and transmit data therebetween using suitable connection arrangement 425, for example, an internal bus as known in the art, including the Inter- IC (I2C) bus, wiring, and printed circuit boards.

[0105] The system 400 includes communication interface 450 that enables communication with other devices via communication channel 460. The communication interface 450 can include, but is not limited to, a transceiver configured to transmit and to receive data over communication channel 460. The communication interface 450 can include, but is not limited to, a modem or network card and the communication channel 460 may be implemented, for example, within a wired and / or a wireless medium.

[0106] Data is streamed, or otherwise provided, to the system 400, in various examples, using a wireless network such as a Wi-Fi network, for example IEEE 802.11 (IEEE refers to the Institute of Electrical and Electronics Engineers). The Wi-Fi signal of these examples is received over the communications channel 460 and the communications interface 450 which are adapted for Wi-Fi communications. The communications channel 460 of these examples is typically connected to an access point or router that provides access to external networks including the Internet for allowing streaming applications and other over-the-top communications. Other examples provide streamed data to the system 400 using a set-top box that delivers the data over the HDMI connection of the input block 445. Still other examples provide streamed data to the system 400 using the RF connection of the input block 445. As indicated above, various examples provide data in a non-streaming manner. Additionally, various examples use wireless networks other than Wi-Fi, for example a cellular network or a Bluetooth® network.

[0107] The system 400 can provide an output signal to various output devices, including a display 475, speakers 485, and other peripheral devices 495. The display 475 of various examples includes one or more of, for example, a touchscreen display, an organic light-emitting diode (OLED) display, a curved display, and / or a foldable display. The display 475 may be for a television, a tablet, a laptop, a cell phone (mobile phone), or other device. The display 475 can also be integrated with other components (for example, as in a smart phone), or separate (for example, an external monitor for a laptop). The other peripheral devices 495 include, in various examples, one or more of a stand-alone digital video disc (or digital versatile disc) (DVD, for both terms), a disk player, a stereo system, and / or a lighting system. Various examples use one or more peripheral devices 495 that provide a function based on the output of the system 400. For example, a disk player performs the function of playing the output of the system 400.

[0108] In various examples, control signals are communicated between the system 400 and the display 475, speakers 485, or other peripheral devices 495 using signaling such as AV. Link, Consumer ElectronicsControl (CEC), or other communications protocols that enable device-to-device control with or without user intervention. The output devices may be communicatively coupled to system 400 via dedicated connections through respective interfaces 470, 480, and 490. Alternatively, the output devices may be connected to system 400 using the communications channel 460 via the communications interface 450. The display 475 and speakers 485 may be integrated in a single unit with the other components of system 400 in an electronic device such as, for example, a television. In various examples, the display interface 470 includes a display driver, such as, for example, a timing controller (T Con) chip.

[0109] The display 475 and speakers 485 can alternatively be separate from one or more of the other components, for example, if the RF portion of input 445 is part of a separate set-top box. In various examples in which the display 475 and speakers 485 are external components, the output signal may be provided via dedicated output connections, including, for example, HDMI ports, USB ports, or COMP outputs.

[0110] The examples may be carried out by computer software implemented by the processor 410 or by hardware, or by a combination of hardware and software. As a non-limiting example, the examples may be implemented by one or more integrated circuits. The memory 420 may be of any type appropriate to the technical environment and may be implemented using any appropriate data storage technology, such as optical memory devices, magnetic memory devices, semiconductor-based memory devices, fixed memory, and removable memory, as non-limiting examples. The processor 410 may be of any type appropriate to the technical environment, and can encompass one or more of microprocessors, general purpose computers, special purpose computers, and processors based on a multi-core architecture, as non-limiting examples.

[0111] Various implementations involve decoding. "Decoding”, as used in this application, can encompass all or part of the processes performed, for example, on a received encoded sequence in order to produce a final output suitable for display. In various examples, such processes include one or more of the processes typically performed by a decoder, for example, entropy decoding, inverse quantization, inverse transformation, and differential decoding. In various examples, such processes also, or alternatively, may include processes performed by a decoder of various implementations described in this application, for example, obtaining a plurality of block vector based merge candidates for a current block, selecting a predictor from the plurality of block vector-based merge candidates, determining whether local illumination compensation (LIC) is enabled for the current block based on the predictor, and decoding the current block based on the determination.

[0112] As further examples, in one example "decoding” refers only to entropy decoding, in another example "decoding” refers only to differential decoding, and in another example "decoding” refers to a combination of entropy decoding and differential decoding. Whether the phrase "decoding process” is intended to refer specifically to a subset of operations or generally to the broader decoding process will beclear based on the context of the specific descriptions and is believed to be well understood by those skilled in the art.

[0113] Various implementations involve encoding. In an analogous way to the above discussion about "decoding”, "encoding” as used in this application can encompass all or part of the processes performed, for example, on an input video sequence in order to produce an encoded bitstream. In various examples, such processes include one or more of the processes typically performed by an encoder, for example, partitioning, differential encoding, transformation, quantization, and entropy encoding. In various examples, such processes also, or alternatively, may include processes performed by an encoder of various implementations described in this application, for example, obtaining a plurality of block vector based merge candidates for a current block, selecting a predictor from the plurality of block vector-based merge candidates, determining whether local illumination compensation (LIC) is enabled for the current block based on the predictor, and encoding the current block based on the determination.

[0114] As further examples, in one example "encoding” refers only to entropy encoding, in another example "encoding” refers only to differential encoding, and in another example "encoding” refers to a combination of differential encoding and entropy encoding. Whether the phrase "encoding process” is intended to refer specifically to a subset of operations or generally to the broader encoding process will be clear based on the context of the specific descriptions and is believed to be well understood by those skilled in the art.

[0115] When a figure is presented as a flow diagram, it should be understood that it also provides a block diagram of a corresponding apparatus. Similarly, when a figure is presented as a block diagram, it should be understood that it also provides a flow diagram of a corresponding method / process.

[0116] The implementations and aspects described herein may be implemented in, for example, a method or a process, an apparatus, a software program, a data stream, or a signal. Even if only discussed in the context of a single form of implementation (for example, discussed only as a method), the implementation of features discussed can also be implemented in other forms (for example, an apparatus or program). An apparatus may be implemented in, for example, appropriate hardware, software, and firmware. The methods may be implemented in, for example, a processor, which refers to processing devices in general, including, for example, a computer, a microprocessor, an integrated circuit, or a programmable logic device. Processors also include communication devices, such as, for example, computers, cell phones, portable / personal digital assistants ("PDAs"), and other devices that facilitate communication of information between end-users.

[0117] Reference to "one example” or "an example” or "one implementation” or "an implementation”, as well as other variations thereof, means that a particular feature, structure, characteristic, and so forth described in connection with the example is included in at least one example. Thus, the appearances of thephrase "in one example” or "in an example” or "in one implementation” or "in an implementation”, as well any other variations, appearing in various places throughout this application are not necessarily all referring to the same example.

[0118] Additionally, this application may refer to "determining” various pieces of information. Determining the information can include one or more of, for example, estimating the information, calculating the information, predicting the information, or retrieving the information from memory. Obtaining may include receiving, retrieving, constructing, generating, and / or determining.

[0119] Further, this application may refer to "accessing” various pieces of information. Accessing the information can include one or more of, for example, receiving the information, retrieving the information (for example, from memory), storing the information, moving the information, copying the information, calculating the information, determining the information, predicting the information, or estimating the information.

[0120] Additionally, this application may refer to "receiving” various pieces of information. Receiving is, as with "accessing”, intended to be a broad term. Receiving the information can include one or more of, for example, accessing the information, or retrieving the information (for example, from memory). Further, "receiving” is typically involved, in one way or another, during operations such as, for example, storing the information, processing the information, transmitting the information, moving the information, copying the information, erasing the information, calculating the information, determining the information, predicting the information, or estimating the information.

[0121] It is to be appreciated that the use of any of the following “ / ”, "and / or”, and "at least one of, for example, in the cases of “A / B”, "A and / or B” and "at least one of A and B”, is intended to encompass the selection of the first listed option (A) only, or the selection of the second listed option (B) only, or the selection of both options (A and B). As a further example, in the cases of "A, B, and / or C” and "at least one of A, B, and C”, such phrasing is intended to encompass the selection of the first listed option (A) only, or the selection of the second listed option (B) only, or the selection of the third listed option (C) only, or the selection of the first and the second listed options (A and B) only, or the selection of the first and third listed options (A and C) only, or the selection of the second and third listed options (B and C) only, or the selection of all three options (A and B and C). This may be extended, as is clear to one of ordinary skill in this and related arts, for as many items as are listed.

[0122] Also, as used herein, the word "signal” refers to, among other things, indicating something to a corresponding decoder. Encoder signals may include, for example, an encoding function on an input for a block using a precision factor, etc. In this way, in an example the same parameter is used at both the encoder side and the decoder side. Thus, for example, an encoder can transmit (explicit signaling) a particular parameter to the decoder so that the decoder can use the same particular parameter. Conversely, if the decoder already has the particular parameter as well as others, then signaling may be used withouttransmitting (implicit signaling) to simply allow the decoder to know and select the particular parameter. By avoiding transmission of any actual functions, a bit savings is realized in various examples. It is to be appreciated that signaling may be accomplished in a variety of ways. For example, one or more syntax elements, flags, and so forth are used to signal information to a corresponding decoder in various examples. While the preceding relates to the verb form of the word "signal”, the word "signal” may (e.g., may also) be used herein as a noun.

[0123] As will be evident to one of ordinary skill in the art, implementations may produce a variety of signals formatted to carry information that may be, for example, stored or transmitted. The information can include, for example, instructions for performing a method, or data produced by one of the described implementations. For example, a signal may be formatted to carry the bitstream of a described example. Such a signal may be formatted, for example, as an electromagnetic wave (for example, using a radio frequency portion of spectrum) or as a baseband signal. The formatting may include, for example, encoding a data stream and modulating a carrier with the encoded data stream. The information that the signal carries may be, for example, analog or digital information. The signal may be transmitted over a variety of different wired or wireless links, as is known. The signal may be stored on, or accessed or received from, a processor- readable medium.

[0124] Many examples are described herein. Features of examples may be provided alone or in any combination, across various claim categories and types. Further, examples may include one or more of the features, devices, or aspects described herein, alone or in any combination, across various claim categories and types. For example, features described herein may be implemented in a bitstream or signal that includes information generated as described herein. The information may allow a decoder to decode a bitstream, the encoder, bitstream, and / or decoder according to any of the embodiments described. For example, features described herein may be implemented by creating and / or transmitting and / or receiving and / or decoding a bitstream or signal. For example, features described herein may be implemented a method, process, apparatus, medium storing instructions, medium storing data, or signal. For example, features described herein may be implemented by a TV, set-top box, cell phone, tablet, or other electronic device that performs decoding. The TV, set-top box, cell phone, tablet, or other electronic device may display (e.g., using a monitor, screen, or other type of display) a resulting image (e.g., an image from residual reconstruction of the video bitstream). The TV, set-top box, cell phone, tablet, or other electronic device may receive a signal including an encoded image and perform decoding.

[0125] These examples may be performed by a device with at least one processor. The device may be an encoder or a decoder. These examples may be performed by a computer program product which is storedon a non-transitory computer readable medium and includes program code instructions. These examples may be performed by a computer program comprising program code instructions.

[0126] Systems, methods, and instrumentalities are disclosed herein for the field of video compression.

[0127] In examples, a video decoder or video encoder may obtain a plurality of block vector-based merge predictor candidates for a current block. A predictor may be selected from the plurality of block vector-based merge predictor candidates. In examples, the block vector-based merge predictor candidates may be intra template matching (intraTMP) merge predictor candidates or may be intra block copy (IBC) merge predictor candidates. The video decoder or video encoder may determine whether local illumination compensation (LIC) is enabled for the current block based on the predictor. Based on a determination that LIC is enabled for the current block, a prediction block may be generated. The current block may be decoded or encoded based on the prediction block. In examples, the determination of whether LIC is enabled for the current block may be determined based on an LIC usage of the predictor. Based on a determination that LIC is enabled for the current block, LIC parameters may be determined and the LIC parameters may be applied to the prediction block. The current block may be decoded or encoded based on the LIC parameters and the predicted block.

[0128] In examples, an LIC model may be derived based on the predictor. The plurality of block vectorbased merge candidates may be refined based on the LIC model. The LIC parameters may be determined based on the LIC model. In examples, an encoder may refine a plurality of block vector-based merge predictor candidates based on the determination of LIC being enabled. The encoder may include an indication in video data that indicates that LIC is enabled for the current block based on the determination of LIC being enabled. In examples, a decoder may obtain an LIC indication that indicates that LIC is enabled. Based on the LIC indication, the decoder may determine that the LIC is enabled. The plurality of block vector-based merge candidates may be refined based on the LIC indication. In examples, the video decoder or video encoder may sort the plurality of block vector-based merge predictor candidates based on a template matching cost to form a final ordered list of merge candidates. The predictor may be selected from the final ordered list of merge candidates.

[0129] Examples of Intra block copy (IBC) are provided herein. IBC is a tool that may be used for screen content coding. IBC may improve the coding efficiency of screen content materials. Since IBC mode may be implemented as a block level coding mode, block matching (BM) may be performed at the encoder to find the optimal block vector (or motion vector) for each coding unit (CU) (e.g., block or coding block). A block vector may indicate the displacement from the current block to a reference block, which may be already reconstructed inside the current picture. The luma block vector of an IBC-coded CU may be in integer precision. The chroma block vector may round to integer precision (e.g., as well). If combined with AMVR,the IBC mode may switch between 1-pel and 4-pel motion vector precisions. An IBC-coded CU may be treated as the third prediction mode other than intra or inter prediction modes. The IBC mode may be applicable to CUs with both width and height smaller than or equal to 64 luma samples.

[0130] At the CU level, IBC mode may be signaled with an indication (e.g., a flag). IBC may be signaled as IBC AMVP mode or IBC skip / merge mode as follows. For IBC skip / merge mode, a merge candidate index may be used to indicate which of the block vectors in the list from neighboring candidate IBC coded blocks is used to predict the current block. The merge list may include spatial, HMVP, and pairwise candidates. For IBC AMVP mode, a block vector difference may be coded in the same way as a motion vector difference. Block vector prediction may use two candidates as predictors, one from left neighbor and one from above neighbor (if IBC coded). If either neighbor is not available, a default block vector may be used as a predictor. An indication may be signaled to indicate the block vector predictor index.

[0131] Examples of an IBC reference region are provided herein. To limit memory consumption and decoder complexity, IBC may (e.g., may only) allow the reconstructed portion of the predefined area including the region of the current CTU and some region of the left CTU.

[0132] FIG. 5 illustrates an example of a current CTU processing order and its available reference samples in the current CTU and the left CTU. As shown in FIG. 5, the blocks (e.g., each block) may represent a 64x64 luma sample unit. Depending on the location of the current coding CU location within the current CTU, the following may apply.

[0133] If the current block falls into the top-left 64x64 block of the current CTU, then (e.g., in addition to the already reconstructed samples in the current CTU) the current block may (e.g., may also) refer to the reference samples in the bottom-right 64x64 blocks of the left CTU (e.g., using CPR mode). The current block may (e.g., may also) refer to the reference samples in the bottom-left 64x64 block of the left CTU and the reference samples in the top-right 64x64 block of the left CTU (e.g., using CPR mode).

[0134] If current block falls into the top-right 64x64 block of the current CTU, then (e.g., in addition to the already reconstructed samples in the current CTU) if the luma location (0, 64) relative to the current CTU has not yet been reconstructed, the current block may (e.g., may also) refer to the reference samples in the bottom-left 64x64 block and bottom-right 64x64 block of the left CTU (e.g., using CPR mode). Otherwise, the current block may (e.g., may also) refer to reference samples in bottom-right 64x64 block of the left CTU.

[0135] If current block falls into the bottom-left 64x64 block of the current CTU, then (e.g., in addition to the already reconstructed samples in the current CTU) if the luma location (64, 0) relative to the current CTU has not yet been reconstructed, the current block may (e.g., may also) refer to the reference samples in the top-right 64x64 block and bottom-right 64x64 block of the left CTU (e.g., using CPR mode). Otherwise, thecurrent block may (e.g., may also) refer to the reference samples in the bottom-right 64x64 block of the left CTU (e.g., using CPR mode).

[0136] If a current block falls into the bottom-right 64x64 block of the current CTU, it may (e.g., may only) refer to the already reconstructed samples in the current CTU (e.g., using CPR mode).

[0137] This restriction may allow the IBC mode to be implemented using local on-chip memory for hardware implementations.

[0138] Examples of IBC merge / AMVP list construction are provided herein. The IBC merge / AMVP list construction may by at least one of the following: if an IBC merge / AMVP candidate is valid (e.g., only if an IBC merge / AMVP candidate is valid), the IBC merge / AMVP candidate may be inserted into the IBC merge / AMVP candidate list; above-right, bottom-left, and above-left spatial candidates and one pairwise average candidate may be added into the IBC merge / AMVP candidate list; or template based adaptive reordering (ARMC-TM) may be applied to IBC merge list.

[0139] The HMVP table size for IBC may be increased to 25 entries. After (e.g., up to 20) IBC merge candidates are derived with full pruning, they may be reordered together. A number of candidates (e.g., the first 6 candidates) with the lowest template matching costs may be selected as the final candidates in the IBC merge list (e.g., after reordering).

[0140] The zero vectors' candidates to pad the IBC Merge / AMVP list may be replaced with a set of BVP candidates located in the IBC reference region. A zero vector may be invalid as a block vector in IBC merge mode. The zero vector may be discarded as BVP in the IBC candidate list.

[0141] FIG. 6 illustrates an example of padding candidates for the replacement of the zero-vector in the IBC list. As shown in FIG. 6, three candidates may be located on the nearest corners of the reference region, and three candidates (e.g., three additional candidates) may be determined in the middle of the three subregions (A, B, and C), whose coordinates may be determined by the width, and height of the current block and the AX and AY parameters.

[0142] FIG. 7 illustrates an example of an extended reference region for IBC. In examples, the reference for IBC may be extended to two CTU rows above the CTU being processed by the encoder or the encoder. The reference area for coding CTU (m,n) is shown in FIG. 7. Specifically, for CTU (m,n) to be coded, the reference area may include CTUs with index (m-2,n-2)... (W,n-2),(0,n-1)... (W,n-1),(0,n)...(m,n), where W may denote the maximum horizontal index within the current tile, slice or picture. The per-sample block vector search (or called local search) range may be limited to [-(C « 1), C » 2] horizontally and [-C, C » 2] vertically to adapt to the reference area extension, where C may denote the CTU size.

[0143] Examples of IBC with template matching are provided herein. Template matching based motion search and refinement may be applied to the case of IBC. An IBC-TM merge mode may be used. IBC-TMmerge mode may involve a merge candidate list for block vector (BV) prediction, which may be different from the merge candidate list used by regular IBC merge mode. The candidates may be selected according to pruning with a motion distance between the candidates as in the regular TM merge mode. The zero motion candidates may be replaced by (-W, 0), (0, -H), (-W, -H) MVs.

[0144] In the IBC-TM merge mode, the selected candidates may be refined with template matching. The TM-merge indication may be signaled to indicate the template matching merge IBC mode.

[0145] In the IBC-TM AMVP mode, (e.g., up to) 3 candidates may be selected from the IBC-TM merge list. The candidates (e.g., each of the candidates) may be refined according to template matching techniques and may be sorted according to their resulting TM cost.

[0146] TM refinement may be performed at integer pel position (e.g., if used for IBC). In IBC-TM AMVP mode, TM refinement may be performed either at integer or 4-pel precision (e.g., depending on the AMVR valu)e. The refinement may be done within the existing IBC reference area.

[0147] Examples of IBC interaction with other coding tools are provided herein. The interaction between IBC mode and other inter coding tools, such as pairwise merge candidate, history-based motion vector predictor (HMVP), combined intra / inter prediction mode (CUP), merge mode with motion vector difference (MMVD), and geometric partitioning mode (GPM), may include one of more of the following:

[0148] IBC may be used with pairwise merge candidate(s) and HMVP. A pairwise IBC merge candidate (e.g., new pairwise IBC merge candidate) may be generated by averaging two IBC merge candidates. For HMVP, IBC motion may be inserted into a history buffer for future referencing. IBC may not be used in combination with affine motion. IBC may be used in combination with CUP, MMVD, and GPM. IBC may not be allowed for the chroma coding blocks (e.g., if DUAL_TREE partition is used).

[0149] The current picture may not be included as one of the reference pictures in the reference picture list 0 for IBC prediction. The derivation process of motion vectors for IBC mode may exclude neighboring blocks (e.g., all neighboring blocks) in inter mode and vice versa. At least one of following IBC design aspects may be applied:

[0150] IBC may share the same process as in regular MV merge including with pairwise merge candidate and history-based motion predictor but may disallow TMVP and zero vector because they are invalid for IBC mode. A separate HMVP buffer (e.g., 5 candidates each) may be used for conventional MV and IBC. Block vector constraints may be implemented in the form of bitstream conformance constraint. The encoder may (e.g., may need to) ensure that no invalid vectors are present in the bit-stream, and merge may not be used if the merge candidate is invalid (e.g., out of range or 0). Such a bitstream conformance constraint may be expressed in terms of a virtual buffer (e.g., as described herein). For deblocking, IBC may be handled as inter mode. If the current block is coded using IBC prediction mode, AMVR may not use quarter-pel. Instead,AMVR may be signaled to indicate (e.g., only indicate) whether MV is inter-pel or 4 integer-pel. The number of IBC merge candidates may be signaled in the slice header separately from the numbers of regular, subblock, and geometric merge candidates.

[0151] Examples of joint usage of IBC and LIC are provided herein. IBC may be used with the inter prediction enhancement tool called local illumination compensation (LIC). LIC is an inter prediction technique that may model local illumination variation between current block and its prediction block as a function of that between current block template and reference block template. The parameters of the function may be denoted by a scale a and an offset p, which may form a linear equation, that is, o*p[x]+p to compensate illumination changes, where p[x] may be a reference sample pointed to by MV at a location x on reference picture. If wrap around motion compensation is enabled, the MV may be clipped with a wrap around offset taken into consideration. Since a and p may be derived based on current block template and reference block template, no signaling overhead may be required for a and p, except that an LIC indication may be signaled for AMVP mode to indicate the use of LIC.

[0152] LIC may be used for uni-prediction inter CUs with at least one of the following modifications: intra neighbor samples may be used in LIC parameter derivation; LIC may be disabled for blocks with less than 32 luma samples; for both non-subblock and affine modes, LIC parameter derivation may be performed based on the template block samples corresponding to the current CU, instead of partial template block samples corresponding to first top-left 16x16 unit; or samples of the reference block template may be generated by using MC with the block MV without rounding it to integer-pel precision.

[0153] Intra block copy with local illumination compensation (IBC-LIC) may aim at compensating the local illumination variation within a picture between the CU coded with IBC and its prediction block with a linear equation. The parameters of the linear equation may be derived the same as LIC for inter prediction except that the reference template may be generated using block vector in IBC-LIC. IBC-LIC may be applied to IBC AMVP mode and IBC merge mode. For IBC AMVP mode, an IBC-LIC indication may be signaled to indicate the use of IBC-LIC. For IBC merge mode, the IBC-LIC indication may be inferred from the merge candidate.

[0154] Examples of intra template matching prediction (intraTMP) mode are provided herein. intraTMP is a special intra prediction mode that may copy the best prediction block from the reconstructed part of the current frame, whose L-shaped template may match the current template. For a predefined search range, the encoder may search for the most similar template to the current template in a reconstructed part of the current frame and may use the corresponding block as a prediction block. The encoder may (e.g., may then) signal the usage of this mode, and the same prediction operation may be performed at the decoder side.

[0155] FIG. 8 illustrates an example of an intra template matching search area used. A sum of absolute differences (SAD) may be used as a cost function. A given search order of the 6 regions may be utilized,(e.g., R4, R5, R6, R1 , R2, and R3 as shown in FIG. 8). Within the regions (e.g., each region), the decoder may construct a candidate list of (e.g., up to 19) template matching block vectors that may be ranked (e.g., in ascending order) according to the template cost (SAD). At least one of the following modes may be supported: single prediction; a fusion of multiple predictors; sub-pel precision; or linear filter model. For a single predictor, a single predictor may be selected from the candidate list. For fusion of multiple predictors, multiple predictors may be blended multiple to derive the final prediction block (e.g., the blending weights are either computed from the template matching cost of each predictor, or with wiener-filter based weight derivation). For sub-pel precision, if a single predictor is used, sub-pel precision may be used with 1 / 2-pel precision, 1 / 4-pel precision and 3 / 4-pel precision (e.g., each with 8 possible directions). For linear filter model, a linear filter model may be learned between the reference template and current template and may apply the linear model to a reference block (e.g., this mode may be used for single predictor if sub-pel precision is not used).

[0156] The dimensions of all regions (SearchRange_w, SearchRange_h) may be set proportional to the block dimension (BlkW, BlkH) to having a fixed number of SAD comparisons per pixel. That is: SearchRange_w = min(64,a * BlkW)SearchRange_h = min(64,a * BlkH) where ‘a’ may be a constant that controls the gain / complexity trade-off. In practice, ‘a’ may be equal to 5.

[0157] The search range of search regions (e.g., all search regions) may be subsampled by a factor of 3 (e.g., to speed-up the template matching process). A refinement process may be performed (e.g., after finding the best match). The refinement may be done via a second template matching search around the best match with a reduced range.

[0158] The Intra template matching tool may be enabled for CUs with a size of less than or equal to 64 in width and height. This maximum CU size for Intra template matching may be configurable. The Intra template matching prediction mode may be signaled at the CU level through a dedicated indication if DIMD is not used for current CU.

[0159] Examples of intra TMP based on a linear filter model (Intra TMP-FLM prediction mode) are provided herein. Intra TMP may be used in combination with convolution filtering as follows.

[0160] FIG. 9 illustrates an example of a spatial part of a filter. In examples, a 6-tap filter, which may include a 5-tap plus sign shape spatial component and a bias term, may be adaptively used to enhance the Intra TMP block prediction. The input to the spatial 5-tap component of the filter may include a center C sample in the reference block (e.g., which is at corresponding locations with the sample in the current block to be predicted) and its above / north (N), below / south (S), left / west (W) and rig ht / east € neighbors, as shown in FIG. 9.

[0161] The bias term B may represent a scalar offset between the input and output and is set to middle luma value (512 for 10-bit content). The output of the filter may be calculated as follows: predLumaVal = cOC + d N + c2S + c3E + c4W + c5B

[0162] FIG. 10 illustrates an example of a reference area used to derive filter coefficients. The filter coefficients ci may be calculated by minimizing the MSE between the reference template and current template (e.g., as shown in FIG. 10). Template size and shapes may be same as in intraTMP. The template size used for training may be four lines above and to the left of the current block depending on their availability. The extensions to the area shown in a blue area may (e.g., may be needed to) support the side samples of the plus shaped spatial filter and may be padded (e.g., if in unavailable areas).

[0163] Usage of the Intra TMP-FLM mode may be signaled by a coded CU level indication. Specifically, Intra TMP-FLM may be considered a sub-mode of Intra TMP. That is, a Intra TMP-FLM indication may be (e.g., may only be) signaled if the intra TMP indication is true.

[0164] The above filtering technique may be proposed in other examples, which may include applying the linear filter model to IBC predicted blocks. This filtered mode may be used as an additional mode for nonmerge IBC blocks. For non-merge blocks, this mode may not be applied together with IBC-LIC, IBC-CIIP, or RR-IBC. For IBC merge modes, this filtering mode may be inherited when a merge mode list is constructed (e.g., so there may be no extra signaling).

[0165] The adaptive usage of the LIC of linear filter model for IBC predicted block may be used together with block-level signaling of the prediction mode, which may lead to increased compression performance. However, with respect to the Intra TMP prediction mode, the combined use (e.g., only the combined use) of Intra TMP with the linear filter model may be considered.

[0166] Examples of intra TMP using LIC are provided herein. The application of LIC to blocks in IntraTMP mode may be allowed. The LIC usage for an IntraTMP mode may be signaled through a CU-level indication, usages of LIC and FLM (CCCM-like filtering) may be mutually exclusive for a given CU; or usages of LIC and fusion in intra TMP may be mutually exclusive (e.g., similarly to FLM). An adaptive template for LIC linear model computation may be (e.g., may further be) used (e.g., as well as multiple linear model) to further increase the compression efficiency (e.g., for screen content coding).

[0167] Examples of using Intra TMP with merge candidates are provided herein. In an example, augmenting the IntraTMP candidate list with predictors specified by a block vector from the neighboring PUs may be provided. Specifically, the same candidate list as for IBC may be considered for IntraTMP. Whenever a block vector is found in the merge list, the block vector may be added to the current IntraTMP candidate list. The candidate list may be refined with a second template matching (e.g., which may be already used in IntraTMP). In this example, the IntraTMP candidate list may be enriched block vectors that may not bepreviously checked by an IntraTMP process. This is because the IntraTMP process may include IBC block vectors, whose search region may be larger than IntraTMP one, and also because the IntraTMP process may include some candidates that are not selected in the first pass of template matching (e.g., the coarse search with subsampled regions). The added block vectors may be correlated with the current block statistics as they were selected previously for predicting nearby blocks.

[0168] Examples of an IBC-LIC model merge mode are provided herein. In examples, the IBC-LIC model merge mode may be proposed to inherit IBC-LIC model parameters from previously coded blocks and to update the additive component of the selected LIC model. In examples, the IBC-LIC model merge mode may be proposed to inherit IBC-LIC model parameters from previously coded blocks. An IBC-LIC model for an IBC-LIC model merge mode may be obtained by constructing a model candidate list which may include model parameters from spatial adjacent and non-adjacent neighbors, history candidates, and default models. The size of the candidate list may be 12. IBC-LIC models may be collected from the blocks previously coded in IBC-LIC and IBC-LIC model merge modes in both adjacent and non-adjacent positions. If an IBC-LIC model candidate is a multi-model IBC-LIC coded block, the parameters from two linear models and the classification threshold may be inherited accordingly. A history IBC-LIC model table with a size of six may be maintained similar to the history-based motion vector prediction (HMVP) table. The IBC-LIC models from spatial neighbors and the history IBC-LIC model table may be added to the IBC-LIC model merge candidate list. If the list is not full, a default model and the scaled models may (e.g., may then) be added to the list. To avoid redundant models, a pruning operation may (e.g., may also) be applied.

[0169] An IBC-LIC model for an IBC-LIC model merge mode may be obtained by selecting an IBC-LIC model from the candidate list and signaling its index in the bitstream. The p parameter of the LIC model may be inherited and may not be modified. In IBC-merge mode, the selected LIC model may be applied to the reference template during merge list reordering. The IBC merge list may (e.g., may then) be sorted (e.g., further sorted) by the inherited IBC LIC indication. The proposed mode may be used (e.g., may be used only) if there is an adjacent block that is coded as IBC-LIC or the proposed mode. In the IBC-AMVP mode, the selected LIC model may be applied to the reference template during BVD prediction. An indication may be signaled to indicate whether the proposed IBC-LIC merge mode is applied or not. If this indication is true, an index may be signaled (e.g., further signaled) to indicate which candidate model may be used by the current block. The indication may be (e.g., may only be) signaled if the current block is not coded as IBC-CIIP, IBC- GPM, TM-Merge, or skip mode.

[0170] Examples herein may improve the compression efficiency of video codecs for blocks coded in intra TMP mode and for blocks employing LIC-based prediction enhancement. IntraTM P-LIC prediction mode may be used together with a merge mode mechanism involving LIC information.

[0171] In examples, intra TMP merge mode may be applied to the derivation of the LIC usage indication (e.g., flag) and LIC model information from the block selected for block vector information in the intra IMP merge mode. In examples, IntraTM P-LIC prediction mode may be combined with the IBC-LIC model merge mode.

[0172] In examples, if block vector information is derived in the Intra-TMP merge mode, the LIC indication may be derived from a merge candidate coding unit (CU) (e.g., block or coding block) coded in IBC-LIC mode or in IntraTMP-LIC mode. If block vector information is derived in the Intra-TMP merge mode, the LIC model information may (e.g., may also) be derived from the intra TMP candidate indicated by the intra TMP index.

[0173] In examples, if an inherited LIC indication is true, then template matching refinement of block vector may be applied. An LIC model may (e.g., may then) be computed based on refined block vector. In examples, if an inherited LIC indication is true, then the LIC model of current CU may be computed. The inherited block vector may (e.g., may then) be refined based on the computed LIC mode.

[0174] In examples, the LIC model may be applied (e.g., may first be applied) to the entire template of the reference block used for template matching based block vector refinement. The inherited block vector may (e.g., may then) be refined based on a LIC-transformed reference template. In examples, the inherited LIC model may be (e.g., may first be applied) to the entire template of the reference block used for template matching based block vector refinement. The inherited block vector may (e.g., may then) be refined based on the LIC-transformed reference template.

[0175] In examples, a similar LIC model merge mode may be applied for coding units coded in IntraTMP- LIC mode as for CUs coded IBC-LIC model merge mode. If a CU is coded / decoded in IntraTMP-LIC, then the associated LIC indication and model information of the CU may be considered when computing the IBC- LIC model merge candidate list of future CUs coded in IBC-LIC or IntraTMP-LIC mode. If a CU is coded in IntraTMP-LIC mode, the IBC-LIC mode merge mode may not be used for the current CU, but the LIC model information may be included in the IBC-LIC merge candidate list for subsequent CUs in current pictures that are coded in IBC-LIC mode.

[0176] In examples, if deriving block vector information in the Intra-TMP merge mode, the LIC indication information may (e.g., may also) be derived from the candidate selected in the IBC merge candidate list. The LIC model information of the current CU may (e.g., may also) be included into the IBC-LIC merge candidate list for subsequent CUs in current pictures that are coded in IBC-LIC mode.

[0177] FIG. 11 illustrates an example of an intra TMP mode parsing process according to a combination of IntraTM P and LIC. As shown in FIG. 11 , if the CU is in intraTMP mode, not in IntraTM P fusion mode and not in FLM mode, then the LIC indication of a considered CU may be parsed. The LIC indication may indicate if LIC is used in the considered CU.

[0178] FIG. 12 illustrates an example of deriving a LIC indication based on a selected predictor (e.g., intraTMP merge candidate). In this example, an LIC indication may not be signaled and decoded at the CU level (e.g., contrary to FIG. 11). The LIC usage for an IntraTMP coding unit may be derived from the merge predictor selected in the merge candidate list. The set of candidate IntraTMP predictors may be derived from the template matching search process of IntraTMP and from the IntraTMP merge candidates. In examples, a video encoder or decoder may obtain a plurality of block vector based (e.g., intraTMP or IBC) merge predictor candidates for a current block. The plurality of block vector-based predictor merge candidates may be refined. The plurality of merge candidates may be sorted based on template matching. A predictor may be selected from the plurality of block vector-based merge candidates (e.g., indicated by a parsed intraTMP index). The video encoder or decoded may determine whether LIC is enabled for the current block based on the selected predictor. The current block may be encoded or decoded based on the determination of whether LIC is enabled for the current block based on the selected predictor.

[0179] When deriving IntraTMP merge candidates, not only may the block vector be derived from a previously coded IBC or IntraTMP CU, but also its LIC indication and possibly its LIC model (a and p parameters). The merge candidates may be refined based on template matching (TM) cost. The final set of candidates may be sorted based on TM cost.

[0180] The LIC indication associated with the current CU (e.g., issued from the parsing stage as shown in FIG. 11) may be checked. If LIC is enabled for the current CU, a prediction block may be generated and LIC linear model parameters (e.g., noted a and b) may be determined for the current CU and applied to the prediction block in the same way as for Inter or IBC CU. Decoding of the current block includes a determination of the LIC parameters and a determination of the (e.g., final) prediction (e.g., prediction block) based on the LIC parameters. For example, the final prediction of the current CU may be computed as pred_Final=axpred_lntraTMP+b as is done for Inter and IBC block in LIC mode.

[0181] If the LIC indication is not enabled for current CU, the FLM filtering taps may be computed based on CU template and prediction block template (e.g., if linear filter model (FLM) usage is on). The linear filter model may be applied to computed final predicted CU. The (e.g., final) prediction of the current CU may be taken as the Intra TMP predicted block, for example, if FLM is off.

[0182] The CU residual block may be decoded and may be added to the final predicted CU (e.g., to produce the reconstructed coding unit) if the (e.g., final) prediction of current CU is obtained. The example as shown in FIG. 12 may end after the CU residual block is decoded and added to the final predicted CU.

[0183] In this example, determining whether LIC is enabled for the current block may be determined based on the selected predictor. In examples, whether LIC enabled for the current block may be determined by an LIC usage of the selected predictor. LIC usage may be fully inferred for coding units coded in IntraTMP mode,through the derivation of LIC information from a previously coded CU (e.g., in IBC or IntraTMP mode). No signaling may be needed to jointly use IntraTMP prediction with LIC, leading to potentially reduced bitrate and improved compression efficiency.

[0184] FIG. 13 illustrates an example of deriving an LIC model based on a selected IntraTMP predictor (e.g., selected merge candidate). In this example, not only may the LIC usage indication be derived through the IntraTMP merge mechanism, but also the LIC model of a CU previously coded in IBC-LIC or IntraTMP- LIC mode. As shown in FIG. 13, no computation (e.g., new computation) of the LIC model for current CU may be needed before applying the LIC step to the prediction block. In examples, the LIC model may be derived based on the selected predictor. The plurality of block vector-based merge candidates may be refined based on the LIC model. The video encoder or decoder may determine the LIC parameters based on the LIC model.

[0185] In examples, the LIC model inherited through the IntraTMP merge mechanism may be taken into account during the block vector refinement process (e.g., for IntraTMP candidate(s) with an inherited LIC indication equal to true). To do so, the reciprocal transform of the LIC operation with inherited LIC model (a,p) may be applied to the template samples of current block. The following operation may be applied to each reconstructed luma sample recY in current CU's template:

[0186] The template matching based refinement of inherited block vector may minimize the TM cost between the template of candidate reference blocks in the already reconstructed part of the picture, and the inverse-LIC transformed template of current block. The block vector with minimum TM cost may be obtained after forward LIC transform is applied to reference template, which may improve block vector selection and improve compression efficiency.

[0187] In examples, the additive part p (e.g., only the additive part p) of the inherited LIC model may be taken into account during the BV refinement process (e.g., a value may be set to 1 in above equation to apply inverse LIC transform to current block's template). In examples, the template matching based sorting of IntraTMP predictors may (e.g., may also) consider the LIC model inherited through the IntraTMP merge mode. For IntraTMP candidates issued from the IntraTMP merge derivation and with the inherited LIC indication equal to true, the forward LIC transform may be applied to the template area of the considered candidate, with inherited LIC model parameters (o,p). IntraTMP candidates (e.g., all IntraTMP candidates), with LIC on or off, may (e.g., may then) be sorted based on template matching cost to form the final ordered list of IntraTMP predictor candidates. In examples (e.g., in the above TM-cost-based sorting process of IntraTMP candidates), the additive part p (e.g., only the additive part p) of the inherited LIC model may beconsidered when applying forward LIC transform to the template of each candidate with the inherited LIC indication equal to true.

[0188] FIG. 14 illustrates an example of derived an LIC mode based on a merge mechanism with explicit signaling of an LIC indication. In examples, an encoder may refine the plurality of block vector-based merge candidates based on determining that LIC is enabled. The encoder may include an indication in video data that indicates LIC is enabled for the current block based on the determination of LIC being enabled. A decoder may obtain the LIC indication that indicates the LIC is enabled. Based on the LIC indication, the decoder may refine the plurality of merge candidates. Based on the LIC indication, the decoder may determine that LIC is enabled.

[0189] As described in FIG. 13, the block vector, LIC indication, and LIC model information may be derived from IntraTMP merge candidates. The differences in FIG. 14 may be at least the following aspects. During the block vector refinement process of IntraTMP candidates, the derived LIC model may be considered the same way as in FIG. 13, only if the parsed LIC indication is equal to true. Otherwise, no LIC model may be considered during the block vector refinement process. During the TM-cost-based sorting of IntraTMP candidate, the inherited LIC model may (e.g., may only) be considered if the LIC indication issued from the parsing of FIG. 11 is true. In that case, a similar sorting process as in FIG. 13 takes place. Otherwise, other IntraTMP candidate sorting examples may be applied. During block prediction, the LIC stage may be applied according to the LIC indication value. If true, then LIC may be applied as follows. If a derived LIC model (o,p) is available (e.g., issued from IntraTMP merge derivation) then the derived LIC mode may be used for the application of LIC on current block prediction. If no LIC model is available (e.g., the IntraTMP candidate selected by the IntraTMP index is not issued from an IntrTMP merge candidate with LIC on), then the LIC model of current block may be computed.

[0190] FIG. 15 illustrates an example of an indication that indicates if an inherited LIC indication is used for a current block. In this example, the LIC-related parsed syntax element may not be a simple LIC usage indication (e.g., as shown in FIG. 11). On the contrary, the LIC-related parsed syntax element may be in an indication indicating if the LIC usage information derived for each IntraTMP prediction candidate is correct or not. During the IntraTMP prediction candidate list construction, intraTMP prediction candidates (e.g., each IntraTMP prediction candidate) may be assigned a LIC indication. This indication may be set to true if the IntraTMP candidate is issued from an IntraTMP merge candidate with the LIC indication on. Otherwise, the indication may be set to false. As such, IntraTMP candidates (e.g., all IntraTMP candidates) issued from template matching search (e.g., as opposed to IntraTMP merge derivation) may be given an initial LIC indication value set to false.

[0191] The final LIC indication of IntraTMP candidates (e.g., each IntraTMP candidate) may (e.g., may then) be computed as follows by the decoder. If the parsed LIC predict indication is true, then the initial assigned LIC value of current CU may be correct and left unchanged. In the opposite case, if parsed LIC predict indication is false, then the initial LIC indication value may be changed to its opposite value. This example may result in reduced entropy of the signaled LIC-related indication, which may result in reduced bitrates.

[0192] FIG. 16 illustrates an example of intra TMP merge list construction according to an LIC indication value. As shown in FIG. 16, the LIC usage indication may be explicitly signaled for CUs (e.g., each CU) coded in IntraTM P-LIC mode.

[0193] This example derives the candidates in the IntraTMP merge mode differently than in FIG. 15. In this example, the type of candidates retrieved in the IntraTMP merge mode may depend on the parsed LIC indication of the considered CU. If the LIC is equal to true, then (e.g., only) IntraTMP merge candidates issued from neighboring and non-neighboring already coded CU in IntraTM P-LIC or IBC-LIC mode may be considered. As such, the overall list of IntraTMP prediction candidates may be made of candidates resulting from usual TM-based IntraTMP search, and merge candidates with LIC indication equal to true.

[0194] If the parsed LIC indication is false for a considered CU, the candidates derived through the IntraTMP merge mechanism may (e.g., may only) include neighboring and non-local CUs coded in IntraTMP or OBC mode, but with LIC indication equal to false. As such, the overall list of IntraTMP prediction candidates may be made of candidates resulting from (e.g., usual) TM-based IntraTMP search, and merge candidates with LIC indication equal to false.

[0195] In examples, the differentiation between IntraTMP merge candidates with LIC information and candidates without LIC information to be inherited may be performed through the Intra TMP index syntax element. That is, some reserved Intra TMP index values may be used to indicate that the LIC model of the selected Intra TMP candidate is inherited in a current CU. Some reserved Intra TMP index values may (e.g., may also) be kept totally and partially unchanged for the current CU, during the block vector refinement, candidate sorting, or LIC transform processes.

[0196] In examples, the IBC-LIC merge model may be applied to examples using the IntraTM P-LIC coding mode. For example, the same LIC merge model for CUs coded in IntraTMP-LIC mode may be used as for IBC-LIC coding mode.

[0197] With regards to syntax signaling and parsing, the decoder side may parse the LIC indication as shown in FIG. 11 for an IntraTMP coding unit. If LIC indication is true, then a LIC merge index may be (e.g., further) parsed, indicating which LIC-model candidate may be selected to perform LIC for a current CU. Inexamples, the LIC merge model may be indicated through a specific CU-level indication, which may be different from the LIC indication as indicated in FIG. 11 , which may be false.

[0198] If the FIG. 11 LIC indication is on, then LIC processes may apply to current CU involving the computation of current CU's LIC model during the prediction process. On the contrary, if the FIG. 11 LIC indication is false and the LIC merge indication is on, then the LIC model used for current CU may be derived from a candidate in the LIC merge candidate list.

[0199] In examples, the current IntraTMP-LIC coding unit may inherit the LIC model of the selected LIC merge model candidate. As shown in FIG. 14, the so-inherited LIC model may be considered during the sorting of the multiple IntraTMP prediction candidates considered in IntraTMP coding mode. To do so, the forward LIC transform may be applied onto the template of each IntraTMP prediction candidate. In examples, the additive part (e.g., only the additive part) of the inherited LIC model may be considered in this sorting process.

[0200] In examples, for applying LIC to the predicted block in the proposed IntraTMP LIC-merge mode, the additive part (e.g., only the additive part) of the inherited LIC model may be kept unchanged. The scaling parameter a may be recomputed during the prediction stage.

[0201] Another example (e.g., which aims at synergizing the IntraTMP-LIC with the LIG merge mode) may include propagating the LIC information (indication (e.g., flag) and model) of the IntraTMP-LIC coding unit to subsequent coding units of the considered picture, which may be coded in IBC-LIC mode. That is, for a CU coded in IBC-LIC mode and with the LIC merge model, the merge candidate list of LIC models constructed for the considered IBC-LIC CU may include LIC models issued from some previous CU coded in IntraTMP- LIC mode (e.g., in addition to LIC models coming from preceding IBC-LIC coding units). This may lead to improved compression performance, since a richer set LIC merge model candidates may be made available to coding units coded in IBC-LIC mode.

[0202] In examples, a current CU coded in IntraTMP-LIC mode may not be used in the LIC merge model designed for IBC-LIC blocks. However, the propagation of LIC information of IntraTMP-LIC CU to IBC-LIC CU using the LIC merge mode or the IBC merge mode may be used. Hence, the IntraTMP-LIC coding / decoding process may be unchanged, but coding units coded in IBC-merge mode or in the LIC-merge mode may benefit from the LIC information associated with preceding coding units coded in IntraTMP-LIC mode. With respect to the usual IBC merge mode, this means that not only may the block vector coming from IntraTMP CUs be integrated into the IBC merge list, but also LIC information coming from these IntraTMP CUs. With respect to the LIC merge mode, this means that in addition to LIC models coming from preceding IBC-LIC CUs, LIC models coming from preceding IntraTMP-LIC CUs may also be considered to construct the LIC model merge candidate list.

[0203] In examples, a hybrid approach between the IntraTMP merge mechanism used for IntraTMP coding unit and the LIC merge model proposed for IBC-LIC coding units may be used for IBC merge and AMVP mode. The propagation of the LIC information associated to IntraTMP-LIC coding units may be propagated to subsequent IBC-LIC coding in same coded picture.

[0204] Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

CLAIMSWhat is Claimed:1 . A device for video decoding, comprising: a processor configured to: obtain a plurality of block vector-based predictor merge candidates for a current block; select a predictor from the plurality of block vector-based merge predictor candidates; determine whether local illumination compensation (LIC) is enabled for the current block based on the predictor; based on a determination that LIC is enabled for the current block, generate a prediction block; and decode the current block based on the prediction block.

2. The device of claim 1 , wherein the processor is further configured to: based on the determination that LIC is enabled for the current block, determine LIC parameters; and, apply the LIC parameters to the prediction block.

3. The device of claim 2, wherein the processor is further configured to: derive an LIC model based on the predictor; refine the plurality of block vector-based merge predictor candidates based on the LIC model; and determine the LIC parameters based on the LIC model.

4. The device of claim 1 , wherein the processor is further configured to: sort the plurality of block vector-based merge predictor candidates based on a template matching cost to form a final ordered list of merge candidates, wherein the predictor is selected from the final ordered list of merge candidates.

5. The device of claim 1 , wherein the determination of whether LIC is enabled for the current block is determined based on an LIC usage of the predictor.

6. The device of claim 1 , wherein the plurality of block vector-based merge predictor candidates are intra template matching (intraTM P) merge predictor candidates or are intra block copy (IBC) merge predictor candidates.

7. A method for video decoding, the method comprising: obtaining a plurality of block vector-based predictor merge candidates for a current block; selecting a predictor from the plurality of block vector-based merge predictor candidates; determining whether local illumination compensation (LIC) is enabled for the current block based on the predictor; based on a determination that LIC is enabled for the current block, generating a prediction block; and decoding the current block based on the prediction block.

8. The method of claim 7, further comprising: based on the determination that LIC is enabled for the current block, determining LIC parameters; and, applying the LIC parameters to the prediction block.

9. The method of claim 8, further comprising: deriving an LIC model based on the predictor; refining the plurality of block vector-based merge predictor candidates based on the LIC model; and determining the LIC parameters based on the LIC model.

10. The method of claim 7, further comprising: sorting the plurality of block vector-based merge predictor candidates based on a template matching cost to form a final ordered list of merge candidates, wherein the predictor is selected from the final ordered list of merge candidates.11 . The method of claim 7, wherein the determination of whether LIC is enabled for the current block is determined based on an LIC usage of the predictor.

12. The method of claim 7, wherein the plurality of block vector-based merge predictor candidates are intra template matching (intraTM P) merge predictor candidates or are intra block copy (IBC) merge predictor candidates.

13. A device for video encoding, comprising: a processor configured to: obtain a plurality of block vector-based predictor merge candidates for a current block; select a predictor from the plurality of block vector-based merge predictor candidates; determine whether local illumination compensation (LIC) is enabled for the current block based on the predictor; based on a determination that LIC is enabled for the current block, generate a prediction block; and encode the current block based on the prediction block.

14. The device of claim 13, wherein the processor is further configured to: based on the determination that LIC is enabled for the current block, determine LIC parameters; and, apply the LIC parameters to the prediction block.

15. The device of claim 14, wherein the processor is further configured to: derive an LIC model based on the predictor; refine the plurality of block vector-based merge predictor candidates based on the LIC model; and determine the LIC parameters based on the LIC model.

16. The device of claim 13, wherein the processor is further configured to: refine the plurality of block vector-based predictor merge candidates based on a determination ofLIC being enabled; and include an LIC indication in video data that indicates that LIC is enabled for the current block based on the determination of LIC being enabled.

17. The device of claim 13, wherein the determination of whether LIC is enabled for the current block is determined based on an LIC usage of the predictor.

18. The device of claim 13, wherein the plurality of block vector-based merge predictor candidates are intra template matching (intraTM P) merge predictor candidates or are intra block copy (IBC) merge predictor candidates.

19. A method for video encoding, the method comprising: obtaining a plurality of block vector-based predictor merge candidates for a current block; selecting a predictor from the plurality of block vector-based merge predictor candidates; determining whether local illumination compensation (LIC) is enabled for the current block based on the predictor; based on a determination that LIC is enabled for the current block, generating a prediction block; and encoding the current block based on the prediction block.

20. The method of claim 19, further comprising: based on the determination that LIC is enabled for the current block, determining LIC parameters; and, applying the LIC parameters to the prediction block.

21. The method of claim 20, further comprising: deriving an LIC model based on the predictor; refining the plurality of block vector-based merge predictor candidates based on the LIC model; and determining the LIC parameters based on the LIC model.

22. The method of claim 19, further comprising: refining the plurality of block vector-based predictor merge candidates based on a determination of LIC being enabled; and including an LIC indication in video data that indicates that LIC is enabled for the current block based on the determination of LIC being enabled.

23. The method of claim 19, wherein the determination of whether LIC is enabled for the current block is determined based on an LIC usage of the predictor.

24. The method of claim 19, wherein the plurality of block vector-based merge predictor candidates are intra template matching (intraTM P) merge predictor candidates or are intra block copy (IBC) merge predictor candidates.

Images