Chroma direct mode

Abstract

A video decoder may be configured to identify chroma blocks in received video data. The video decoder may determine, from the received video data, that DM intra prediction is applied to the chroma block. The video decoder may retrieve data associated with a luma block corresponding to the identified chroma block. The data associated with the luma block may indicate that a DIMD, a TIMD, an IntraTMP, and / or an SGMP are associated with the luma block. Under conditions that the received data indicates that DM intra prediction is applied to the chroma block and the data associated with the corresponding luma block indicates that DIMD and / or TIMD, IntraTMP, and / or SGMP are to be applied to the luma block, the video decoder may determine that DIMD and / or TIMD, IntraTMP, and / or SGMP may similarly be applied to the corresponding chroma block.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of European Patent Application No. 22305489.1 filed on April 8, 2022 and European Patent Application No. 22307025.1 filed on December 23, 2022, the entire contents of all of which are incorporated herein by reference. Background Art

[0003] Video coding systems may be used to compress digital video signals, for example, to reduce the storage and / or transmission bandwidth required for such signals. Summary of the invention

[0004] Disclosed are systems, methods, and means for decoding a chroma block of video data using a mode associated with a corresponding luma block under the condition that a direct mode (DM) is applied to the chroma block of video data. If the chroma block may be in DM mode and the corresponding luma block may have had decode-side intra mode derivation (DIMD), template-based intra mode derivation (TIMD), intra template matching prediction (IntraTMP), and / or spatial geometry prediction mode (SGPM) applied to the luma block, then the chroma block may also have had DIMD, TIMD, IntraTMP, and / or SGPM applied to the chroma block.

[0005] The video encoder may be configured to determine that the chrominance block can be encrypted and decrypted using the same intra-frame prediction mode as the corresponding luminance block. The video encoder may determine that the luminance block and the corresponding chrominance block can be processed using DIMD, TIMD, IntraTMP and / or SGPM. The video encoder may generate encoded video data including an indication of using DM to process the chrominance block. The data may include a flag indicating that DM is used to process the chrominance block. The video data may also include data indicating that the corresponding luminance block can be processed using DIMD, TIMD, IntraTMP and / or SGPM. The video data may also include data indicating that a low-frequency non-separable transform (LFNST) index and / or a multi-transform selection (MTS) index are applied to the luminance block. The encoder may transmit the video data to a video decoder.

[0006] The video decoder may be configured to receive the video data and determine or identify the chrominance block. The video decoder may also determine from the received video data that the DM mode may be applied to the chrominance block. For example, the video decoder may identify a flag indicating that DM may be applied to the chrominance block.

[0007] The video decoder may retrieve data from the video data for the luma block corresponding to the identified chroma block. The data associated with the luma block may indicate an intra prediction mode for the luma block. For example, the data associated with the luma block may indicate that DIMD, TIMD, IntraTMP, and / or SGPM are associated with the luma block and are to be applied to the luma block.

[0008] Under the condition that the received data indicates that DM is applied to the chrominance block and the data associated with the corresponding luma block indicates that DIMD, TIMD, IntraTMP and / or SGPM are to be applied to the luma block, the video decoder may determine that DIMD, TIMD, IntraTMP and / or SGPM are similarly applicable to the corresponding chrominance block. The video decoder may perform the DIMD, TIMD, IntraTMP and / or SGPM as specified in the data associated with the corresponding luma block on the chrominance block. Under the condition that the received data also indicates that LFNST index and / or MTS index are to be applied for the luma block, the video decoder may apply the specified LFNST and / or MTS to the corresponding chrominance block.

[0009] The systems, methods, and means may involve decoders. In some examples, the systems, methods, and means described herein may involve encoders. In some examples, the systems, methods, and means described herein may involve signals (e.g., signals from encoders and / or received by decoders). A computer-readable medium may include instructions for causing one or more processors to perform the methods described herein. A computer program product may include instructions that, when executed by one or more processors, cause the one or more processors to perform the methods described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented.

[0011] Figure 1B is an example of a method that can be used according to an embodiment of the present invention. Figure 1A System diagram of an example wireless transmit / receive unit (WTRU) for use within the communication system illustrated in FIG.

[0012] Figure 1C is an example of a method that can be used according to an embodiment of the present invention. Figure 1A System diagram of an example radio access network (RAN) and an example core network (CN) for use within the communication system illustrated in FIG.

[0013] Figure 1D is an example of a method that can be used according to an embodiment of the present invention. Figure 1ASystem diagram of yet another example RAN and yet another example CN used within the communication system illustrated in FIG.

[0014] Figure 2 An example block-based video encoder is illustrated.

[0015] Figure 3 An example video decoder is illustrated.

[0016] Figure 4 Examples of systems in which various aspects and examples may be implemented are illustrated.

[0017] Figure 5 Example intra prediction modes in VVC and ECM are illustrated.

[0018] Figure 6 An example derivation of a Most Probable Mode (MPM) list is illustrated.

[0019] Fig. 7A and Figure 7B Example signaling of a selected intra-prediction mode is illustrated.

[0020] Figure 8 Example signaling of a selected intra-prediction mode is illustrated.

[0021] Fig. 9 An example intra template matching search area is illustrated.

[0022] Fig.10 An example SGPM template analysis for candidate list construction is illustrated.

[0023] Fig.11 An example process for decoding chroma data using direct mode (DM) intra prediction and DIMD / TIMD is illustrated. DETAILED DESCRIPTION

[0024] A more detailed understanding may be obtained from the following description given by way of example in conjunction with the accompanying drawings.

[0025] Figure 1A1 is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through sharing of system resources (including wireless bandwidth). For example, the communication system 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 multi-carrier (FBMC), etc.

[0026] like Figure 1A As shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, public switched telephone network (PSTN) 108, Internet 110 and other networks 112, but it should be understood 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 “STA”) may be configured to send and / or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated process chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0027] The communication system 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 that is 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 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, an NR Node B, 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.

[0028] 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), a relay node, etc. The base station 114a and / or the base station 114b may be configured to send and / or receive wireless signals on one or more carrier frequencies (which may be referred to as cells (not shown)). These frequencies may be in a licensed spectrum, an unlicensed spectrum, or a combination of licensed and unlicensed spectrums. A cell may provide coverage of wireless services to a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, a cell associated with the base station 114a may be divided into three sectors. Therefore, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver 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 send and / or receive signals in a desired spatial direction.

[0029] 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).

[0030] More specifically, as noted above, the communication 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, etc. 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 use Wideband CDMA (WCDMA) to establish the air interface 115 / 116 / 117. 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).

[0031] 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) that may establish the air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-A Pro).

[0032] In one 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).

[0033] 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 together implement LTE radio access and NR radio access, for example using the dual connectivity (DC) principle. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0034] 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), etc.

[0035] Figure 1A The base station 114b in the may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a business location, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, 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 a femtocell. As Figure 1A As shown, base station 114b may have a direct connection to Internet 110. Therefore, base station 114b may not need to access Internet 110 via CN 106 / 115.

[0036] 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 different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform advanced security functions, such as user authentication. Although not described in detail in the text, the CN 106 / 115 may be 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 different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform advanced security functions, such as user authentication. Figure 1AAlthough not shown in the figure, 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 utilize NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0037] 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 other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides 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), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired communication networks and / or wireless communication 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.

[0038] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication 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 via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0039] Figure 1B is a system diagram illustrating an example WTRU 102. Figure 1B As shown, the WTRU 102 may include, among other things, 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. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0040] 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 associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal decoding, 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. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0041] The send / receive element 122 may be configured to send a signal to a base station (e.g., base station 114a) or receive a signal from the base station by an air interface 116. For example, in one embodiment, the send / receive element 122 may be an antenna configured to send and / or receive an RF signal. In an embodiment, the send / receive element 122 may be a transmitter / detector configured to send and / or receive, for example, IR, UV or visible light signals. In another embodiment, the send / receive element 122 may be configured to send and / or receive both RF signals and optical signals. It should be understood that the send / receive element 122 may be configured to send and / or receive any combination of wireless signals.

[0042] Although the transmit / receive element 122 Figure 1B 1 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.

[0043] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0044] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an 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 a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a 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 a memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0045] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control power to 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, etc.

[0046] 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 from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0047] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules 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 electronic compass, a satellite transceiver, a digital camera (for photos and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, module, a frequency modulation (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, etc. Peripheral device 138 may include one or more sensors, which may be one or more of the following: 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.

[0048] The WTRU 102 may include a full-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for 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 for reducing and / or substantially eliminating self-interference via signal processing performed via hardware (e.g., a choke) or via a processor (e.g., a separate processor (not shown) or via the processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) or downlink (e.g., for reception)) may be concurrent and / or simultaneous.

[0049] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with 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.

[0050] The RAN 104 may include evolved Node-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of evolved Node-Bs while remaining consistent with an embodiment. The evolved Node-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 evolved Node-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0051] Each of the evolved Node 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 UL and / or DL, etc. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0052] Figure 1C The illustrated CN 106 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 is depicted as being part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0053] The MME 162 may be connected to each of the evolved Node-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, etc. 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.

[0054] The SGW 164 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an 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 the user plane during inter-evolved Node-B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

[0055] 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.

[0056] 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 be in communication with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts 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 other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers.

[0057] Although the WTRU Figures 1A to 1D Although described as wireless terminals, it is contemplated that in certain representative embodiments, such terminals may (eg, temporarily or permanently) use a wired communications interface with a communications network.

[0058] In a representative embodiment, the other network 112 may be a WLAN.

[0059] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STA) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or carries traffic away from the BSS. Traffic originating from outside the BSS and leading to the STA may be reached by the AP and may be delivered to the STA. Traffic originating from the STA and leading to a destination outside the BSS may be transmitted to the AP to be delivered to the corresponding destination. Traffic between STAs within the BSS may be transmitted by the AP, for example, wherein the source STA may transmit traffic to the AP, and the AP may deliver traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Direct link establishment (DLS) may be utilized to transmit point-to-point traffic between the source STA and the destination STA (e.g., directly between them). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (eg, all STAs in the STA) may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad hoc" communication mode.

[0060] When using the 802.11ac infrastructure operating mode or a similar operating mode, the AP may send beacons on a fixed channel (such as a primary channel). The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width dynamically set via signaling. The primary channel may be an operating channel of the BSS and may be used by the STA to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access / collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) (including the AP) may listen to the primary channel. In the case where the primary channel is listened / detected and / or determined to be busy by a specific STA, the specific STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0061] High throughput (HT) STAs may communicate using a 40 MHz wide channel, for example, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels to form a 40 MHz wide channel.

[0062] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz channels and / or 80MHz channels can be formed by combining continuous 20MHz channels. 160MHz channels can be formed by combining 8 continuous 20MHz channels, or by combining two non-continuous 80MHz channels (this can be called 80+80 configuration). For 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. Each stream can be processed by inverse fast Fourier transform (IFFT) and time domain processing separately. These streams can be mapped to two 80MHz channels, and data can be sent by the transmitting STA. At the receiver of the receiving STA, the above-mentioned operations for the 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0063] 802.11af and 802.11ah support operating modes below 1GHz. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support instrument type control / machine type communications, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0064] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA (which supports the minimum bandwidth operating mode) from all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) a 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because a STA (supporting only a 1MHz operating mode) is sending to the AP, the entire available frequency band may be considered busy even if most of the frequency bands remain idle and may be available.

[0065] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0066] Figure 1D 1 is a system diagram illustrating the RAN 113 and the CN 115 in accordance with an embodiment. As noted above, the RAN 113 may employ 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.

[0067] 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, the gNBs 180a, 180b may utilize beamforming to send signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may, for example, use multiple antennas to send 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, gNB 180a may transmit multiple component carriers to 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, 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).

[0068] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with parameter sets that may be scalable. For example, 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 the gNBs 180a, 180b, 180c using subframes or Transmission Time Intervals (TTIs) of varying or scalable lengths (e.g., containing varying numbers of OFDM symbols and / or varying absolute time lengths over time).

[0069] 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 a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c while not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gNBs 180a, 180b, 180c as mobility anchors. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with the gNB 180a, 180b, 180c while also communicating / connecting with another RAN, such as the eNode-B 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNode-B 160a, 160b, 160c may act as a mobility anchor for the WTRUs 102a, 102b, 102c, and the gNB 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0070] 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 UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards a user plane function (UPF) 184a, 184b, routing of control plane information towards an access and mobility management function (AMF) 182a, 182b, etc. Figure 1D As shown, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0071] Figure 1DThe illustrated CN 115 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and possible data networks (DNs) 185a, 185b. Although each of the foregoing elements is depicted as part of the CN 115, it should be understood that any of these elements may be owned and / or operated by an entity other than a CN operator.

[0072] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, support of network slicing (e.g., handling of different PDU sessions with different requirements), selecting a specific SMF 183a, 183b, management of registration areas, termination of NAS signaling, mobility management, etc. The AMF 182a, 182b may use network slicing in order to customize CN support for the WTRU 102a, 102b, 102c based on the type of services utilized by the WTRU 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 mobile broadband (eMBB) access, services for machine type communication (MTC) access, etc. 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.

[0073] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 115 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 115 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b, and configure the traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0074] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the 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, etc.

[0075] 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 acts 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 other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b via the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and the N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0076] Given that Figures 1A to 1D as well as Figures 1A to 1D Corresponding to the description of the present invention, one or more or all of the functions described herein with reference to one or more of the following may be performed by one or more simulation devices (not shown): WTRU102a-d, base station 114a-b, evolved Node B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b and / or any other device described herein. The simulation device may be one or more devices configured to mimic one or more or all of the functions described herein. For example, the simulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0077] The simulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more simulation devices may perform one or more functions or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. One or more simulation devices may perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The simulation device may be directly coupled to another device for testing purposes and / or may use over-the-air wireless communications to perform testing.

[0078] One or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device can be used in a test scenario in a test laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via an RF circuit system (e.g., which can include one or more antennas) can be used by the simulation device to send and / or receive data.

[0079] The present application describes a number of aspects, including tools, features, examples, models, methods, etc. Many of these aspects are described in a particular manner, and at least in order to illustrate individual features, are usually described in a manner that may sound restrictive. However, this is to describe clearly and does not limit the application or scope of these aspects. In fact, all different aspects can be combined and interchanged to provide further aspects. In addition, these aspects can also be combined and interchanged with the aspects described in the earlier submission.

[0080] The aspects described and contemplated in this application can be implemented in many different forms. Figures 5 to 11 Some examples may be provided, but others are also contemplated. Figures 5 to 11 The discussion of the present invention does not limit the breadth of specific implementations. At least one of these aspects generally relates to video encoding and decoding, and at least one other aspect generally relates to sending a generated or encoded bitstream. These and other aspects can be implemented as methods, apparatus, a computer-readable storage medium having stored thereon instructions for encoding or decoding video data according to any of the methods, and / or a computer-readable storage medium having stored thereon a bitstream generated according to any of the methods.

[0081] In this application, the terms "reconstruction" and "decoding" are used interchangeably, the terms "pixel" and "sample" are used interchangeably, and the terms "image", "picture" and "frame" are used interchangeably.

[0082] Various methods are described herein, and each method includes one or more steps or actions for implementing the method. Unless the correct operation method requires a specific order of steps or actions, the order and / or purpose of specific steps and / or actions can be modified or combined. In addition, in various examples, terms such as "first", "second" and the like can be used to modify elements, components, steps, operations, etc., such as "first decoding" and "second decoding". Unless specifically required, the use of such terms does not imply the ordering of the modification operation. Therefore, in this example, the first decoding does not need to be performed before the second decoding, and can, for example, occur before, during, or in overlapping time periods of the second decoding.

[0083] The various methods and other aspects described in this application can be used to modify Figure 2 and Figure 3 The modules of the video encoder 200 and decoder 300 shown are, for example, decoding modules. In addition, the subject matter disclosed herein can be applied to, for example, any type, format, or version of video decoding (whether described in a standard or described in a recommendation), whether pre-existing or developed in the future, as well as extensions of any such standards and recommendations. Unless otherwise indicated or technically excluded, the aspects described in this application can be used alone or in combination.

[0084] For the purpose of describing the examples, various numerical values ​​are used in describing the examples of the present application, and the described aspects are not limited to these specific values.

[0085] Figure 2 is a diagram illustrating an example video encoder. Variations of the example encoder 200 are contemplated, but encoder 200 is described herein for clarity without describing all contemplated variations.

[0086] Before being encoded, the video sequence may undergo a pre-encoding process (201), for example, applying a color transform to an input color picture (e.g., conversion from RGB 4:4:4 to YCbCr 4:2:0), or performing a remapping of input picture components to obtain a signal distribution that is more resilient to compression (e.g., using histogram equalization of one of the color components). Metadata may be associated with the pre-processing and appended to the bitstream.

[0087] In encoder 200, a picture is encoded by encoder elements as described herein. The picture to be encoded is partitioned (202) and processed in units such as coding units (CUs). Each unit is encoded, for example, using intra mode or inter mode. When a unit is encoded in intra mode, the unit performs intra prediction (260). Motion estimation (275) and compensation (270) are performed in inter mode. The encoder decides (205) which of intra mode or inter mode to use to encode the unit, and indicates the intra / inter decision by, for example, a prediction mode flag. The prediction residual is calculated, for example, by subtracting (210) the predicted block from the original image block.

[0088] The prediction residual is then transformed (225) and quantized (230). The quantized transform coefficients, along with motion vectors and other syntax elements, are entropy coded (245) to output a bitstream. The encoder may skip the transform and apply quantization directly to the untransformed residual signal. The encoder may bypass the transform and quantization, i.e., directly code the residual without applying the transform or quantization process.

[0089] The encoder decodes the coded block to provide a reference for further prediction. The quantized transform coefficients are dequantized (240) and inverse transformed (250) to decode the prediction residual. The image block is reconstructed by combining the decoded prediction residual and the predicted block (255). An in-loop filter (265) is applied to the reconstructed picture to perform, for example, deblocking / SAO (sample adaptive offset) filtering to reduce coding artifacts. The filtered image is stored at a reference picture buffer (280).

[0090] Figure 3 is a diagram illustrating an example of a video decoder. In the example decoder 300, a bitstream is decoded by a decoder element as described herein. The video decoder 300 generally performs the same Figure 2 The decoding process is the reverse of the encoding process described in . The encoder 200 also typically performs video decoding as part of encoding the video data.

[0091] The input to the decoder includes a video bitstream, which may be generated by the video encoder 200. First, the bitstream is entropy decoded (330) to obtain transform coefficients, motion vectors, and other decoded information. Picture partition information indicates how the picture is partitioned. Therefore, the decoder may partition (335) the picture according to the decoded picture partition information. The transform coefficients are dequantized (340) and inverse transformed (350) to decode the prediction residual. The image block is reconstructed by combining (355) the decoded prediction residual and the predicted block. The predicted block may be obtained (370) from intra-frame prediction (360) or motion compensated prediction (i.e., inter-frame prediction) (375). An in-loop filter (365) is applied to the reconstructed image. The filtered image is stored at a reference picture buffer (380).

[0092] The decoded picture may also undergo post-decoding processing (385), such as an inverse color transform (e.g., a transform from YCbCr 4:2:0 to RGB 4:4:4) or an inverse remapping that performs the inverse of the remapping performed in the pre-encoding process (201). The post-decoding processing may use metadata derived in the pre-encoding process and signaled in the bitstream. In an example, the decoded image (e.g., after applying the in-loop filter (365) and / or after the post-decoding processing (385), if post-decoding processing is used) may be transmitted to a display device for presentation to a user.

[0093] Figure 4 400 is a diagram showing an example of a system in which various aspects and examples described herein can be implemented. System 400 may be embodied as a device including various components described below and configured to perform one or more aspects of the various aspects described in this document. Examples of such devices include, but are not limited to, various electronic devices, such as personal computers, laptop computers, smart phones, tablet computers, digital multimedia set-top boxes, digital television receivers, personal video recording systems, connected home appliances and servers. The elements of system 400 may be embodied in a single integrated circuit (IC), multiple ICs and / or discrete components, either individually or in combination. For example, in at least one example, the processing and encoder / decoder elements of system 400 are distributed over multiple ICs and / or discrete components. In various examples, system 400 is communicatively coupled to one or more other systems or other electronic devices via, for example, a communication bus or through a dedicated input port and / or output port. In various examples, system 400 is configured to implement one or more aspects of the aspects described in this document.

[0094] The system 400 includes at least one processor 410 configured to execute instructions loaded therein for implementing, for example, various aspects described in this document. The processor 410 may include embedded memory, input-output interfaces, and various other circuit systems 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). The system 400 includes a storage device 440, which may include a non-volatile memory and / or a volatile memory, including but not limited to an electrically erasable programmable read-only memory (EEPROM), a read-only memory (ROM), a programmable read-only memory (PROM), a random access memory (RAM), a dynamic random access memory (DRAM), a static random access memory (SRAM), a flash memory, a magnetic disk drive, and / or an optical disk drive. As a non-limiting example, the storage device 440 may include an internal storage device, an attached storage device (including a removable and non-removable storage device), and / or a network-accessible storage device.

[0095] The system 400 includes an encoder / decoder module 430, which is configured to process data, for example, to provide encoded video or decoded video, and the encoder / decoder module 430 may include its own processor and memory. The encoder / decoder module 430 represents a module that may be included in a device to perform encoding and / or decoding functions. As is well known, a device may include one or both of an encoding module and a decoding module. Additionally, the encoder / decoder module 430 may be implemented as a separate element of the system 400, or may be incorporated into the processor 410 as a combination of hardware and software known to those skilled in the art.

[0096] Program code to be loaded onto the processor 410 or the encoder / decoder 430 to perform various aspects described in this document may be stored in the storage device 440 and subsequently loaded onto the memory 420 for execution by the processor 410. According to various examples, one or more of the processor 410, the memory 420, the storage device 440, and the encoder / decoder module 430 may store one or more of various items during the execution of the processes described in this document. Such stored items may include, but are not limited to, input video, decoded video or a portion of decoded video, bitstreams, matrices, variables, and intermediate or final results of processing equations, formulas, operations, and operation logic.

[0097] In some examples, memory inside the processor 410 and / or the encoder / decoder module 430 is used to store instructions and provide working memory for processing required during encoding or decoding. However, in other examples, memory external to the processing device (e.g., the processing device may be the processor 410 or the encoder / decoder module 430) is used for one or more of these functions. The external memory may be a memory 420 and / or a storage device 440, such as a dynamic volatile memory and / or a non-volatile flash memory. In several examples, the external non-volatile flash memory is used to store, for example, an operating system for a television. In at least one example, a fast external dynamic volatile memory (such as RAM) is used as working memory for video encoding and decoding operations.

[0098] Inputs 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) section that receives an RF signal, such as that transmitted 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 ( Figure 4 ) includes composite video.

[0099] In various examples, the input device of block 445 has associated corresponding input processing elements as known in the art. For example, the RF section may be associated with elements applicable to the following: (i) selecting a desired frequency (also referred to as selecting a signal, or band-limiting a signal to a frequency band); (ii) down-converting the selected signal; (iii) again band-limiting to a narrower frequency band to select a signal frequency band that may be referred to as a channel in some examples; (iv) demodulating the down-converted and band-limited signal; (v) performing error correction; and (vi) demultiplexing to select a desired data packet stream. Various examples of the RF section include one or more elements for performing these functions, such as a frequency selector, a signal selector, a band limiter, a channel selector, a filter, a down-converter, a demodulator, an error corrector, and a demultiplexer. The RF section may include a tuner that performs various functions in these functions, including, for example, down-converting a received signal to a lower frequency (e.g., an intermediate frequency or a near-baseband frequency) or to baseband. In a set-top box example, the RF part and its associated input processing element receive the RF signal sent by wired (for example, cable) medium, and filter to the desired frequency band by filtering, down-conversion and again to perform frequency selection.Various examples rearrange the order of above-mentioned (and other) elements, remove some elements in these elements, and / or add other elements that perform similar or different functions.Adding element can include inserting element between existing elements, such as inserting amplifier and analog-to-digital converter.In various examples, the RF part includes antenna.

[0100] Additionally, the USB and / or HDMI terminals may include corresponding interface processors for connecting the system 400 to other electronic devices across the USB and / or HDMI connections. It should be understood that various aspects of input processing (e.g., Reed-Solomon error correction) may be implemented as needed, for example, in a separate input processing IC or in the processor 410. Similarly, various aspects of USB or HDMI interface processing may be implemented as needed in a separate interface IC or in the processor 410. The demodulated, error-corrected, and demultiplexed streams are provided to various processing elements, including, for example, the processor 410 and the encoder / decoder 430, which operate in conjunction with the memory and storage elements to process the data streams as needed for presentation on the output device.

[0101] The various elements of system 400 may be disposed within an integrated housing. Within the integrated housing, the various elements may be interconnected and data may be sent between these elements using a suitable connection arrangement 425 (e.g., an internal bus known in the art, including an inter-IC (I2C) bus, wiring, and a printed circuit board).

[0102] System 400 includes a communication interface 450 that enables communication with other devices via a communication channel 460. Communication interface 450 may include, but is not limited to, a transceiver configured to send and receive data through communication channel 460. Communication interface 450 may include, but is not limited to, a modem or a network card, and communication channel 460 may be implemented, for example, within a wired and / or wireless medium.

[0103] In various examples, data is streamed or otherwise provided to the system 400 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 signals of these examples are received via a communication channel 460 and a communication interface 450 suitable for Wi-Fi communications. The communication channel 460 of these examples is typically connected to an access point or router that provides access to external networks including the Internet to allow streaming applications and other cross-top communications. Other examples provide streaming data to the system 400 using a set-top box that delivers data via an HDMI connection of an input box 445. Still other examples use an RF connection of an input box 445 to provide streaming data to the system 400. As described above, various examples provide data in a non-streaming manner. In addition, various examples use wireless networks other than Wi-Fi, such as cellular networks or network.

[0104] System 400 can provide output signals to various output devices, including display 475, speaker 485 and other peripherals 495. Various examples of display 475 include, for example, one or more of a touch screen display, an organic light emitting diode (OLED) display, a curved display and / or a foldable display. Display 475 can be used for a television, a tablet computer, a laptop, a cellular phone (mobile phone) or other devices. Display 475 can also be integrated with other components (e.g., as in a smart phone), or be independent (e.g., an external monitor for a laptop computer). In various examples, other peripherals 495 include one or more of an independent digital video disc (or digital versatile disc) (DVD, for both terms), a disc player, a stereo system and / or a lighting system. Various examples use one or more peripherals 495, which provide functions based on the output of system 400. For example, a disc player performs the function of playing the output of system 400.

[0105] In various examples, control signals are transmitted between the system 400 and the display 475, speaker 485, or other peripheral device 495 using signaling such as AV.Link, consumer electronics control (CEC), or other communication protocols that enable device-to-device control with or without user intervention. Output devices may be communicatively coupled to the system 400 via dedicated connections through respective interfaces 470, 480, and 490. Alternatively, the output devices may be connected to the system 400 via a communication interface 450 using a communication channel 460. The display 475 and speaker 485 may be integrated into a single unit with other components of the 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 (TCon) chip.

[0106] For example, if the RF portion of input 445 is part of a separate set-top box, display 475 and speaker 485 may alternatively be separate from one or more of the other components. In various examples where display 475 and speaker 485 are external components, output signals may be provided via dedicated output connections including, for example, an HDMI port, a USB port, or a COMP output.

[0107] These examples may be performed by computer software implemented by processor 410 or by hardware or by a combination of hardware and software. As a non-limiting example, these examples may be implemented by one or more integrated circuits. Memory 420 may be of any type suitable for the technical environment and may be implemented using any appropriate data storage technology, such as, as a non-limiting example, optical memory devices, magnetic memory devices, semiconductor-based memory devices, fixed memory, and removable memory. Processor 410 may be of any type suitable for the technical environment and may include, as a non-limiting example, one or more of a microprocessor, a general-purpose computer, a special-purpose computer, and a processor based on a multi-core architecture.

[0108] Various specific implementations involve decoding. As used in this application, "decoding" may cover, for example, all or part of the processes performed on the received encoded sequence to produce a final output suitable for display. In various examples, such processes include one or more processes typically performed by a decoder, such as entropy decoding, inverse quantization, inverse transform, and differential decoding. In various examples, such processes also or alternatively include processes performed by decoders of various specific implementations described in this application, for example, under the condition that the chrominance block can be identified as being in DM, the prediction process associated with the corresponding luminance block is applied to the chrominance block. As another example, 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 specifically refer to a subset of operations or to refer broadly to a broader decoding process will be clear based on the context of the specific description and is considered to be well understood by those skilled in the art.

[0109] Various implementations involve encoding. In a manner similar to the discussion above regarding "decoding", "encoding" as used in this application can encompass, for example, all or part of a process performed on an input video sequence to produce an encoded bitstream. In various examples, such processes include one or more of the processes typically performed by an encoder, such as performing convolution, obtaining latent vectors, generating motion flow data, etc. In various examples, such processes also or alternatively include processes performed by encoders of various implementations described in this application, including, for example, determining that a chroma block may have had the same prediction process applied to the chroma block as the corresponding luminance block and including an indicator in the encoded video data.

[0110] As another example, 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 decoding and entropy encoding. Whether the phrase "encoding process" specifically refers to a subset of operations or broadly refers to a broader encoding process will be clear based on the context of the specific description and is believed to be well understood by those skilled in the art.

[0111] Note that the syntax elements (e.g., coding syntax for latent vectors, attention values, etc.) used herein are descriptive terms. Therefore, they do not exclude the use of other syntax element names.

[0112] When the figures are presented as flow charts, it should be understood that they also provide block diagrams of corresponding devices. Similarly, when the figures are presented as block diagrams, it should be understood that they also provide flow charts of corresponding methods / processes.

[0113] The specific implementations and aspects described herein may be implemented in, for example, methods or processes, devices, software programs, data streams, or signals. Even if discussed only in the context of a single form of specific implementation (e.g., discussed only as a method), the specific implementation of the features discussed may also be implemented in other forms (e.g., devices or programs). Devices may be implemented in, for example, appropriate hardware, software, and firmware. These methods may be implemented in, for example, a processor, which generally refers to a processing device, including, for example, a computer, a microprocessor, an integrated circuit, or a programmable logic device. The processor also includes communication devices, such as, for example, computers, mobile phones, portable / personal digital assistants ("PDAs"), and other devices that facilitate information communication between end users.

[0114] References to "one example" or "an example" or "one implementation" or "an implementation" and other variations thereof mean that a particular feature, structure, characteristic, etc. described in connection with the example is included in at least one example. Thus, the phrases "in one example" or "in an example" or "in one implementation" or "in an implementation" and any other variations appearing in various places throughout this application are not necessarily all referring to the same example.

[0115] Additionally, the present application may involve "determining" various pieces of information. Determining information may include, for example, estimating information, calculating information, predicting information, or retrieving information from a memory. Obtaining may include receiving, retrieving, constructing, generating, and / or determining.

[0116] Furthermore, the present application may refer to "accessing" various information. Accessing information may include, for example, one or more of receiving information, retrieving information (e.g., from a memory), storing information, moving information, copying information, calculating information, determining information, predicting information, or estimating information.

[0117] Additionally, the present application may refer to "receiving" various information. Like "accessing," receiving is intended to be a broad term. Receiving information may include, for example, one or more of accessing information or retrieving information (e.g., from a memory). Furthermore, "receiving" generally involves, in one way or another, during operations such as, for example, storing information, processing information, sending information, moving information, copying information, erasing information, calculating information, determining information, predicting information, or estimating information.

[0118] It should be understood that, for example, in the case of "A / B," "A and / or B," and "at least one of A and B," the use of any of the following " / ," "and / or," and "at least one of" is intended to encompass selecting only the first listed option (A), or only the second listed option (B), or both options (A and B). As a further example, in the case of "A, B, and / or C" and "at least one of A, B, and C," such phrases are intended to encompass selecting only the first listed option (A), or only the second listed option (B), or only the third listed option (C), or only the first listed option and the second listed option (A and B), or only the first listed option and the third listed option (A and C), or only the second listed option and the third listed option (B and C), or all three options (A and B and C). This can be extended to as many items as listed, as will be apparent to one of ordinary skill in this and related arts.

[0119] Moreover, as used herein, the term "signaling" means (among other things) indicating something to a corresponding decoder. The encoder signal may include, for example, an indication of motion stream data, an indication of quantized motion stream data, and the like. Thus, in one example, the same parameters are used at both the encoding end and the decoding end. Thus, for example, the encoder may send (explicit signaling) specific parameters to the decoder so that the decoder can use the same specific parameters. On the contrary, if the decoder already has specific parameters and other parameters, signaling may be used without sending (implicit signaling) to simply allow the decoder to know and select specific parameters. Bit savings are achieved in various examples by avoiding sending any actual function. It should be understood that signaling can be implemented in a variety of ways. For example, in various examples, one or more syntax elements, flags, and the like are used to signal information to the corresponding decoder. Although the verb form of the term "signaling" is mentioned above, the term "signal" may also be used as a noun in this article.

[0120] It will be apparent to one of ordinary skill in the art that a specific implementation may generate a variety of signals formatted to carry, for example, storable or transmittable information. The information may include, for example, instructions for executing a method or data generated by one of the described specific implementations. For example, a signal may be formatted to carry a bit stream of the described examples. Such a signal may be formatted as, for example, an electromagnetic wave (e.g., using a radio frequency portion of a spectrum) or a baseband signal. Formatting may include, for example, encoding a data stream and modulating a carrier using the encoded data stream. The information carried by the signal may be, for example, analog or digital information. As is well known, a signal may be sent over a variety of different wired or wireless links. The signal may be stored on, or accessed or received from, a processor-readable medium.

[0121] Many examples are described herein. The features of the examples may be provided individually or in any combination across various claim categories and types. In addition, the examples may include one or more of the features, devices or aspects described herein individually or in any combination across various claim categories and types. For example, the features described herein may include a bitstream or signal of information generated as described herein to be implemented. This information may allow a decoder to decode a bitstream, an encoder, a bitstream and / or a decoder according to any of the embodiments described. For example, the features described herein may be implemented by creating and / or sending and / or receiving and / or decoding a bitstream or a signal. For example, the features described herein may be implemented by a method, a process, a device, a medium storing instructions, a medium storing data or a signal. For example, the features described herein may be implemented by a TV, a set-top box, a mobile phone, a tablet computer or other electronic devices that perform decoding. A TV, a set-top box, a mobile phone, a tablet computer or other electronic devices may display (e.g., using a monitor, a screen or other type of display) the resulting image (e.g., an image reconstructed from the residual of a video bitstream). A TV, a set-top box, a mobile phone, a tablet computer or other electronic devices may receive a signal including an encoded image and perform decoding.

[0122] Disclosed are systems, methods, and means for encoding and decoding chroma blocks of video data using a mode associated with a corresponding luma block under the condition that a direct mode (DM) is applied to the chroma blocks. If the chroma blocks may be in DM mode and the corresponding luma blocks have had decode-side intra mode derivation (DIMD), template-based intra mode derivation (TIMD), intra template matching prediction (IntraTMP), and / or spatial geometric prediction mode (SGPM) (e.g., prediction processes) applied to the luma blocks, then the chroma blocks may also have DIMD, TIMD, IntraTMP, and / or SGPM (e.g., prediction processes) applied to the chroma blocks.

[0123] A video decoder may be programmed to receive video data and determine or identify a chroma block in the video data. The video decoder may determine from the received video data that direct mode (DM) intra prediction may be associated with the chroma block. For example, the video decoder may identify a flag in the video data indicating that DM intra prediction may be applied to the chroma block.

[0124] The video decoder may retrieve data from the received video data for the luma block corresponding to the identified chroma block. The data associated with the luma block may indicate an intra-prediction mode for the luma block. For example, the data may indicate that DIMD, TIMD, IntraTMP, and / or SGPM are associated with the luma block and are to be applied to the luma block. Under the condition that the received data indicates that DM intra-prediction is applied to the chroma block and the data associated with the corresponding luma block indicates that DIMD, TIMD, IntraTMP, and / or SGPM (e.g., a prediction process) is to be applied to the luma block, the video decoder may determine that DIMD, TIMD, IntraTMP, and / or SGPM (e.g., a prediction process) may be similarly applied to the corresponding chroma block. The video decoder may perform intra-prediction on the chroma block consistent with the intra-prediction mode identified for the luma block, and may perform DIMD, TIMD, IntraTMP, and / or SGPM on the chroma block as specified in the data associated with the corresponding luma block. Under the condition that the received data also indicates a LFNST index or an MTS index for the luma block, the video decoder may apply the specified LFNST and / or MTS to the corresponding chroma block.

[0125] The disclosed systems, methods, and means may be applied in the context of video decoding. The disclosed systems, methods, and means may be applied to the chroma direct mode (DM), where the chroma intra prediction mode may be similar to (e.g., the same as) the luma intra prediction mode. The systems, methods, and means may process chroma blocks using decode-end intra mode derivation (DIMD), template-based intra mode derivation (TIMD), IntraTMP, and / or SGPM under the condition that DIMD, TIMD, IntraTMP, and / or SGPM are applied to the corresponding luma block. If DM is used, the transform index that may be applied to the luma block may also be applied to the associated chroma block.

[0126] Intra-frame prediction may be a basic coding tool used, for example, in hybrid video coding. For a given block to be predicted, the encoder may select, for example, the best intra-frame prediction mode in terms of rate distortion, and may signal the index of its intra-frame prediction mode to the decoder so that the decoder may perform the same prediction for the particular block. Signaling the selected intra-frame prediction mode index may add additional overhead and may reduce the gain from intra-frame prediction. One way to decode the index of the intra-frame prediction mode selected to predict a given block may be to create a most probable mode (MPM) set. If the index of the selected intra-frame prediction mode belongs to the list, using the MPM set may reduce signaling overhead. This method may be used in VVC and HEVC, such as a classical method for signaling the intra-frame prediction mode index (which may be referred to as, for example, signaling based on an MPM list). Signaling based on an MPM list may be used in ECM, where two MPM lists may be used instead of one. It should be understood that with respect to signaling based on an MPM list, signaling of a mode index may be referred to as signaling of a mode for short.

[0127] In HEVC, VVC, and ECM, MPM list-based signaling may (e.g., may only) be dedicated to signaling of the intra-prediction mode selected to predict the luma block. Chroma intra-prediction mode signaling may be different from luma intra-prediction mode signaling. In conjunction with chroma processing, signaling overhead may be kept relatively small because, for a given chroma block pair (e.g., a clustered collocated Cb block and Cr block), the selected intra-prediction mode may be (e.g., may only be) any of the following intra-prediction modes: planar; DC; horizontal; vertical; or the same as the intra-prediction mode selected to predict the luma block collocated with the particular chroma block pair. Direct mode (DM) may be considered to apply when the mode is the same as the intra-prediction mode selected to predict the luma block collocated with the particular chroma block pair. In VVC and ECM, for a given chroma block pair, the selected intra-prediction mode may also be a cross-component linear model (CCLM) mode.

[0128] In ECM, luma intra prediction can be enhanced by two decoding-side mode derivation methods: decoding-side intra mode derivation (DIMD); and template-based intra mode derivation (TIMD). If a given pair of chroma blocks (e.g., a collocated Cb block and Cr block) can be coded using DM intra prediction mode and a luma block collocated with a pair of chroma blocks uses TIMD or DIMD, then the intra prediction mode for the pair of chroma blocks can be the same derived intra mode specified in the data for the luma block. However, since DIMD / TIMD may not be applied to chroma blocks under existing procedures, applying DM to chroma blocks may limit coding performance.

[0129] Disclosed herein are systems, methods, and means for performing DIMD / TIMD on a pair of chroma blocks when DM is selected and a luma block collocated with a given pair of chroma blocks is decoded using DIMD / TIMD. If DM is selected and the luma block complies with multiple transform selection (MTS) and / or low frequency non-separable transform (LFNST) (e.g., a transform process), the corresponding chroma block may also comply with the MTS and / or LFNST (e.g., the transform process). This may achieve chroma MTS and reduce chroma LFNST signaling.

[0130] Sixty-seven core intra prediction modes may be available. To capture arbitrary edge directions present in natural video, the number of directional intra prediction modes in VVC may be extended to 65 from 33 as used in HEVC. Figure 5 Describes the intra prediction modes available in VVC and ECM. Compared to HEVC, the additional directional modes in VVC are available in Figure 5 Indicated by dotted lines in . As shown, this additional mode leads to a denser selection of possible intra prediction modes. The denser directional intra prediction mode can be applied to all block sizes and luminance and chrominance intra prediction. In VVC, several conventional angle intra prediction modes can be adaptively replaced with wide-angle intra prediction modes for non-square blocks.

[0131] From HEVC to VVC, the planar mode and DC mode may remain unchanged, excluding the following minor modifications. In HEVC, an intra-coded block (e.g., each intra-coded block) may have a square shape, and the length of each of the sides of the intra-coded block may be a power of two. Therefore, a division operation may not be required to generate an intra-frame predictor using the DC mode. In VVC, blocks may have a rectangular shape, which generally allows (e.g., requires) the use of a division operation per block. In order to avoid a division operation for DC prediction, the longer side (e.g., only the longer side) may be used to calculate the average value of the non-square block.

[0132] In ECM, the core structure of sixty-seven intra prediction modes can be inherited from VVC. This core structure can be optimized in ECM. The four-tap interpolation for directional intra prediction mode can be changed to six-tap interpolation. Position-dependent intra prediction combination (PDPC) can be supplemented with gradient PDPC.

[0133] Intra-prediction mode signaling may be supported by ECM. Intra-prediction mode signaling may be applied to luma. In ECM, if the intra-prediction mode selected to predict the current luma coding block (CB) is neither DIMD nor a matrix-based intra-prediction (MIP) mode or TIMD (e.g., the mode may be one of the 67 intra-prediction modes mentioned herein), the MPM list of the CB may be used to signal its index. According to some protocols, block differential pulse code modulation (BDPCM), template-based intra-prediction (TMP), intra-block copying (IBC), and palettes may be ignored because these tools may be activated specifically for a specific video sequence (e.g., screen content). In ECM, the general MPM list may be decomposed into a list of six primary MPMs and a list of twenty-two secondary MPMs. Figure 6 An example derivation of a generic MPM list for a current luma CB belonging to an intra slide in an ECM is depicted. The generic MPM list can be constructed by adding candidate intra prediction mode indices in order from the most likely candidate to the least likely candidate for predicting the selected intra prediction mode for the current luma CB. Figure 6 From left to right, the sequential addition of candidate intra prediction mode indices is depicted in the case where the current luma CB may belong to an intra slice. There may be no redundancy in the common list of the MPM, which means that the common list may not contain two identical intra prediction mode indices. Figure 6 An example is illustrated in which each candidate intra-frame prediction mode index may be different from each other. However, in the general example, the time slots of indexes 0 to i-1 included in the general list of the MPM may have been previously filled. If the current candidate intra-frame prediction mode index already exists in the current general list of the MPM, the candidate may be skipped, and if the current candidate intra-frame prediction mode index does not exist in the general list of the MPM, the next candidate intra-frame prediction mode may be inserted at the time slot of index i. Otherwise, the current intra-frame prediction mode index may be inserted at the time slot of index i, and if the current intra-frame prediction mode index does not exist in the general list of the MPM, the next candidate intra-frame prediction mode may be inserted at the time slot of index i+1.

[0134] Fig. 7A and Figure 7B Depicted is an example signaling of the intra prediction mode selected to predict the current luma CB in the ECM. Fig. 7A and Figure 7B In the example signaling depicted in , the signaling can be applied to the encoding end processing. The example signaling can also be applied to the decoding end processing. Fig. 7A and Figure 7BIn, MRL can be used to represent multiple reference lines. If the TIMD flag is equal to 1, the MRL index may belong to {0,1,3}. The MRL index at 0 may indicate that the MRL is not used to predict the current brightness CB. The MRL index at 1 may indicate that the reference samples decoded in the second row above the current brightness CB and the reference samples decoded in the second column on the left side of the current brightness CB can be used for prediction. The MRL index at 3 may indicate that the reference samples decoded in the fourth row above the current brightness CB and the reference samples decoded in the fourth column on the left side of the current brightness CB can be used for prediction. If the TIMD flag is equal to 0, the MRL index may belong to {0,1,3,5,7,12}. ISP represents intra-frame sub-partitioning. The ISP mode index may belong to {0,1,2}. The ISP mode index at 0 may indicate that the ISP may not be used for the current brightness CB. The ISP mode index at 1 may indicate that the current brightness CB can be horizontally divided into brightness transform blocks (TBs). The ISP mode index at 2 may indicate that the current brightness CB can be vertically divided into brightness TBs. In Fig. 7A and Figure 7B In , BDPCM, TMP, IBC, and palettes are omitted because these tools can be turned on specifically for a video sequence (e.g., a specific video sequence).

[0135] Intra prediction mode signaling in chroma may be supported in ECM. Figure 8 Depicted is an example signaling of an intra prediction mode selected to predict a current chroma CB pair (e.g., a concatenated Cb CB and Cr CB) in an ECM. Figure 8 In ECM, if the DM flag is equal to 1, the four possibilities of the current intra prediction mode index can be the index of the planar mode, the horizontal mode, the vertical mode and the DC. To avoid redundancy, if DM is one of the above four modes, in the set of the four modes, the index of the redundant mode can be replaced by the index of the vertical diagonal mode. In ECM, the cross-component linear model (CCLM) can aggregate six different intra prediction modes, which can be represented as LM, MMLM, MDLM_L, MDLM_T, MMLM_L and MMLM_T. In VVC, CCLM can aggregate three (e.g., only three) intra prediction modes.

[0136] Decoding-side intra mode derivation (DIMD) may be supported. For a given luma CB to be predicted, DIMD may derive two intra prediction modes from a template of reconstructed neighboring samples surrounding the CB, and may combine these two predictors with a planar mode predictor using weights derived from gradients in the template. The division operations in the weight derivation may be performed using the same lookup table (LUT)-based integerization scheme used by CCLM. For example, the division operation in the orientation calculation Orient=G y / G x It can be calculated by the following LUT-based scheme:

[0137] x=Floor(Log2(Gx))

[0138] normDiff=((Gx<<4)>>x)&15

[0139] x+=(3+(normDiff!=0)?1:0)

[0140] Orient=(Gy*(DivSigTable[normDiff]|8)+(1<<(x-1)))>>x

[0141] in

[0142] DivSigTable

[16] ={0,7,6,5,5,4,4,3,3,2,2,1,1,1,1,0}.

[0143] These two derived intra modes can be included in the common MPM list. Therefore, for a given luma CB to be predicted, the DIMD process can be performed before creating the MPM list. For a given luma CB, the main intra modes derived by DIMD can be stored and used for MPM list construction of neighboring luma CBs.

[0144] IntraTMP in ECM may be supported. Intra-frame template matching prediction (which may be referred to as IntraTMP or TMP) may be an intra-frame prediction mode, for example, a special intra-frame prediction mode, which may copy a prediction block (e.g., an optimal prediction block) from a reconstructed portion of a current frame, whose L-shaped template matches the current template. For a predefined search range, the encoder may search for a template similar to the current template (e.g., the most similar template) in the reconstructed portion of the current frame, and may use the corresponding block as a prediction block. The encoder may transmit information indicating that the mode is being used. The same prediction operation may be performed at the decoding end.

[0145] Fig. 9 An example intra-frame template matching search area is depicted. This can be done by comparing the L-shaped causal neighbors of the current block with the Fig. 9 Another block in the predefined search area depicted in the figure is matched to generate a prediction signal. Fig. 9 In the depicted example, the search region may consist of: R1: current CTU; R2: upper left CTU; R3: upper CTU; and R4: left CTU. SAD may be used as a cost function.

[0146] Within each region, the decoder may search for a template having a SAD (eg, a minimum SAD) with respect to the current template and may use the corresponding block of the template as a prediction block.

[0147] The size of the region, for example all regions (SearchRange_w, SearchRange_h) may be set proportional to the block size (BlkW, BlkH) to have a fixed number of SAD comparisons per pixel. For example, SearchRange_w may be determined as follows: SearchRange_w = a*BlkW. SearchRange_h may be determined as follows: SearchRange_h = a*BlkH. For both, 'a' may be a constant that controls the gain / complexity tradeoff. For example, 'a' may be equal to 5.

[0148] The intra template matching tool may be enabled for CUs with width and height sizes less than or equal to, for example, 64. This CU size (eg, maximum CU size) used for intra template matching may be configurable.

[0149] Spatial GPM (SGPM) in ECM can be supported. In this mode, several combinations of intra prediction modes and partitions can be tested on the reconstructed template. Fig.10 Depicted is an example SGPM template analysis for candidate list construction.

[0150] In an example implementation, twenty-six (26) partition modes may be tested. For each partition, three intra prediction modes may be predefined. These modes may consist of an intra prediction mode parallel to the partition direction and two modes derived from a TIMD (template-based intra mode derivation) process. In general, seventy-eight (e.g., 26×3=78) combinations may be considered (as indicated in Table 1 below). In each combination, the current partition may be used on the template, and each combination of two modes may be tested. That is, for three modes, three (3) modes may be tested (e.g., the first mode and the second mode, the first mode and the third mode, and the last second mode and the third mode). The distance (SATD) between the reconstructed template and the prediction using the current partition may be calculated. Sixteen (16) candidates (e.g., the best candidates, each of which may contain a partition mode and two intra prediction modes) may be retained and placed in the SGPM candidate list. The encoder may transmit information identifying an index to indicate which of the candidates may be selected based on their rate-distortion analysis.

[0151] Table 1 SGPM combinations of partition mode and intra mode

[0152]

[0153] Fusion for template-based intra mode derivation (TIMD) may be supported. For the current luma CB, for each intra prediction mode in its MPM list supplemented with a default mode, the SATD between the prediction of the template of the CB via a specific mode and the reconstructed samples of the template may be calculated. The two intra prediction modes with the smallest SATD may be selected as TIMD modes. For TIMD, the SATD may be calculated by Figure 5 The direction is inserted between each arrow in to expand the set of directional intra-frame prediction modes from 65 to 129. The set of possible intra-frame prediction modes derived via TIMD can gather 131 modes. After retaining two intra-frame prediction modes from the first test involving the MPM list supplemented with the default mode, for each of the two modes, if the mode is neither planar nor DC, TIMD can also test its two closest extended directional intra-frame prediction modes in terms of predicting SATD. After applying PDPC, the two TIMD modes generated by the two tests can be fused with weights. Such weighted intra-frame prediction can be used to decode the current brightness CB. PDPC can be included in the derivation of TIMD mode.

[0154] The costs of the two selected modes can be compared to a threshold. In this test, a cost factor of 2 can be applied as follows: costMode2<2*costMode1. If this condition is true, fusion can be applied. Otherwise, mode 1 (e.g., only mode 1) can be used. The weights of these modes can be calculated based on their SATD costs as follows:

[0155] weight1=costMode2 / (costMode1+costMode2)

[0156] weight2=1-weight1

[0157] The division operation may be performed using the same lookup table (LUT) based integerization scheme used by the CCLM.

[0158] According to some procedures, chroma MTS may not be supported in VVC or ECM.

[0159] Chroma LFNST may be supported. LFNST may be applied to luma and chroma components. A CU flag, which may be named lfnst_idx, may be signaled to indicate the use of LFNST. LFNST may be (may be, for example, only) allowed for dual trees of intra-predicted CUs.

[0160] Disclosed are systems, methods, and means for encoding and decoding chroma blocks of video data in the event that direct mode (DM) intra prediction may be applied to the chroma blocks. If DM intra prediction is specified for one or more chroma blocks, prediction information specified for the corresponding luma block may be applied to the chroma block. An intra prediction mode specified for the luma block is determined to be applied to the chroma block. If the corresponding luma block is specified to be decoded using DIMD and / or TIMD, the chroma block is also determined to be decoded using DIMD and / or TIMD. Transform information associated with the luma block may be applied to the corresponding chroma block. An MTS index associated with the luma block may be applied to the chroma block, and an LFNST index associated with the luma block may be applied to the corresponding chroma block.

[0161] The video encoder may be configured to determine that the chrominance block can be encrypted and decrypted using the same intra prediction mode as the corresponding luminance block. The video encoder may also be configured to determine that the luminance block and the corresponding chrominance block can be processed using DIMD and / or TIMD. The video encoder may be configured to include encoded video data indicating the use of DM intra prediction to process the chrominance block. The data may include a flag indicating the use of DM intra prediction to process the chrominance block. The video data may also include data indicating that the corresponding luminance block can be processed using DIMD, TIMD, IntraTMP and / or SGPM. The video data may also include data indicating a low frequency non-separable transform (LFNST) index, a multi-transform selection (MTS) index and / or a multi-reference line (MRL) for the luminance block. The encoder may transmit the video data to the video decoder.

[0162] Fig.11 Depicted is an example processing of transmitted data at a video decoder. The video decoder may be configured to receive the video data and determine or identify chrominance blocks in the video data. Fig.11 At 910, the video decoder may determine from the received video data that direct mode (DM) intra prediction may be applied to the chroma block. For example, the video decoder may identify a flag in the video data indicating that DM intra prediction may be applied to the chroma block.

[0163] If the video decoder determines not to apply DM intra processing to a particular chroma block, the decoder may determine at 912 to use conventional chroma intra mode processing to decode the chroma data. As shown, the decoder may determine from the received video data a particular intra prediction mode that was used to encode the chroma block. The decoder may determine which of the DC mode, planar mode, vertical mode, or horizontal mode was used to code the chroma block. At 914, the decoder may use the identified mode in the mode to perform intra prediction.

[0164] At 916, the decoder may decode low frequency non-separable transform (LFNST) index data from the received data. If direct mode (DM) is not applied, LFNST may be performed on the chroma data if a flag (e.g., lfnst_idx) is signaled to indicate that LFNST may be applied to the chroma data. At 918, the decoder may employ the LFNST index data to perform inverse LFNST using the output from the intra prediction at 914.

[0165] At 920, the decoder may perform an inverse transform process on the output from the LFNST process at 918. In the event that direct mode (DM) may not have been specified for a particular chroma block, the decoder may determine that multiple transform selection (MTS) may not be used when processing the chroma block. Fig.11 As shown, the decoder may determine to set the MTS index to 0, which indicates that MTS processing may not be applied to this particular chroma block.

[0166] If the decoder determines from the received data at 910 that a direct mode (DM) intra prediction mode is applied to the received chroma block, the decoder processing may proceed using the intra prediction data associated with the corresponding luma block. Under the condition that the decoder determines that the DM intra prediction mode is applied to the chroma block, the decoder may perform the processing at 930, 914, 918, and 920. At 930, the decoder may retrieve the intra prediction data associated with the corresponding luma block. As shown, the data for the corresponding luma block may identify the intra prediction mode for the luma block, and may also identify whether decoding-side intra mode derivation (DIMD) and / or template-based intra mode derivation (TIMD) is applied to the luma block.

[0167] Under the condition that the received video data indicates that DM intra-frame prediction is applied to the particular chrominance block, at 914, the decoder may use the retrieved data corresponding to the luma block to perform intra-frame prediction on the particular chrominance block. Therefore, the decoder may apply the particular intra-frame prediction mode specified for the corresponding luma block to the chrominance block. If the retrieved data for the luma block indicates that a planar intra-frame prediction mode is applied, the decoder may use the planar mode to perform intra-frame prediction. If the retrieved data for the luma block indicates that a DC mode is applied, the decoder may use the DC mode to perform intra-frame prediction. If the retrieved data for the luma block indicates that a horizontal mode is applied, the decoder may use the horizontal mode to perform intra-frame prediction.

[0168] If the data for the luma block indicates that DIMD or TIMD is to be applied, then at 914, the decoder may apply the specified DIMD or TIMD to the particular chroma block. In the processing associated with the ECM, chroma DIMD may be employed. The same process used for luma DIMD processing may be applied to chroma processing. A flag (e.g., an additional flag) may be transmitted or signaled by the encoder to indicate that chroma DIMD is to be used. The flag may be signaled to the decoder from the encoder and may be retrieved from the received data at 930. If direct mode is utilized to decode chroma and luma is DIMD, the same method may be applied. DIMD for direct mode and may improve the overall bit rate gain.

[0169] Two example implementations may be considered. A first example implementation may use a chroma DIMD process (e.g., a readily available chroma DIMD process) in ECM, which may derive a chroma mode by analyzing the luma of the two chroma channels. A second implementation may reuse the results of luma DIMD. The luma DIMD process may derive two modes, which may be combined with a planar mode using blending weights (e.g., predefined blending weights).

[0170] The first implementation may reuse the existing chroma DIMD architecture. However, the first implementation may be redundant for chroma DIMD signaling. In other words, there may be two (2) ways to signal chroma DIMD, one using the chroma DIMD flag and the other using direct mode. Therefore, a second implementation may be considered in which a prediction (e.g., a new prediction) may be obtained by mixing three (3) intra modes (e.g., two (2) derived modes and a planar mode).

[0171] If the corresponding luma block is TIMD coded, TIMD may be enabled for the chroma block. Thus, if the data for the luma block indicates application of TIMD, at 914, the decoder may apply TIMD to the corresponding chroma block. Chroma TIMD coding may improve compression, and may also improve compression without additionally signaling that it is designated for luma processing. TIMD processing may be performed as described herein.

[0172] Two example implementations may be considered. A first example implementation may use a TIMD process to derive a chrominance mode (e.g., an optimal chrominance mode) by testing possible modes (e.g., all possible modes) on a reconstructed template, and may select a TIMD process that minimizes the SATD between the reconstructed template and the predicted template. A second implementation may include reusing a TIMD mode derived from luma. The first implementation may be applied to two chrominance components. However, the second implementation may have the benefit of reusing a pre-computed mode and combining it with predefined blending weights.

[0173] refer to Fig.11 , the retrieved intra prediction data for the luma block may indicate (e.g., at 930) a luma LFNST index (e.g., a transform process). At 918, the decoder may apply the indicated LFNST for the chroma block. As described in conjunction with 916, if direct mode (DM) is not applied, LFNST may be performed on the chroma data if a flag (e.g., lfnst_idx) is signaled for the dual tree to indicate that LFNST may be applied to the chroma data. However, if direct mode (DM) intra prediction is applied, LFNST may be applied to the chroma data using the same index corresponding to the luma data. In this case, the flag lfnst_idx may not be signaled for the LFNST to be applied to the chroma data.

[0174] The prediction data for the retrieval of the luma block may also indicate (e.g., at 930) a luma MTS index (e.g., a transform process). At 920, the decoder may use the luma MTS index to perform an inverse transform on the chroma block. If direct mode (DM) coding is applied to the chroma data, MTS may be enabled for chroma. The same transform pair selection used for luma data may be used for chroma. In ECM, the luma MTS may be a block size and related to the intra mode. The chroma MTS may also be a block size and related to the intra mode. However, the chroma may have a size that may not be defined for the transform. That is, the chroma may be up to 2×N, N×2, or 2×2. For these and similar cases, MTS may not be used and a DCT-II transform may be used, for example, a DCT-II transform may be used alternatively.

[0175] It should be understood that if direct mode (DM) is applied to chroma data, the MRL index data associated with the luma block may also be used in chroma. MRL may be enabled without additional signaling, as the DM flag may be used to indicate MRL.

[0176] IntraTMP may be employed. If the collocated luma block uses IntraTMP (e.g., at 930), it may be determined that chroma IntraTMP is applied in case of direct mode. The following implementations may be considered: recalculating the IntraTMP of the chroma components (calculating the IntraTMP of Cb and Cr; or calculating them once); and reusing the luma IntraTMP for the chroma components. The first implementation may provide flexibility, such as the highest flexibility, which may result in greater computational complexity than the second implementation.

[0177] SGPM may be employed. If the collocated luma block uses SGPM (e.g., at 930), it may be determined that SGPM is applied in the case of direct mode. The following implementations may be considered: recalculating SGPM for chroma components (calculating the best 2 intra modes and split lines for each component or both components); and reusing luma SGPM for chroma components (reusing chroma 2 intra modes and split lines for each component). The first implementation may provide flexibility, such as the highest flexibility, which may result in greater computational complexity than the second implementation.

[0178] A transform copy flag may be used. A single flag (e.g., a direct mode flag) may be used to signal transform and prediction information. Signaling may be decoupled and two flags may be used. A direct mode flag may be used to copy the luma intra prediction mode, and a second flag may be used to copy the transform information. Using two flags may provide the encoder with additional flexibility in choosing to copy prediction or transform information.

[0179] Although features and elements are described herein in specific combinations, it will be understood by those of ordinary skill in the art that each feature or element may be used alone or in any combination with 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 (sent via a wired or wireless connection) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as built-in hard disks and removable disks), magneto-optical media, and optical media (such as CD-ROM disks and digital versatile disks (DVDs)). A processor associated with software may be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A decoding device, the decoding device comprising: A processor, the processor being configured to: Obtain video data; Determining a chrominance block from the video data; determining, based on the video data, that a direct mode (DM) applies to the chroma block; retrieving data associated with a luma block associated with the chroma block based on a determination that the DM applies to the chroma block, the data associated with the luma block indicating a prediction process; as well as The prediction process is applied to the chroma block. 2 . The apparatus of claim 1 , wherein the processor configured to determine that DM applies to the chroma block is further configured to determine that DM applies to the chroma block based on a flag in the video data.

3. The device according to claim 1, The prediction process includes decoding-end intra mode derivation (DIMD).

4. The device according to claim 1, The prediction process includes template-based intra mode derivation (TIMD).

5. The device according to claim 1, The prediction process includes intra-frame template matching prediction (IntraTMP).

6. The device according to claim 1, The prediction process includes spatial geometric prediction mode (SGPM) prediction.

7. The device according to claim 1, The prediction process includes multiple reference line (MRL) prediction.

8. The apparatus of claim 1, wherein the processor is further configured to: retrieving data associated with the luma block indicating a transform process based on the determination that DM applies to the chroma block; and The transform process is applied to the chroma blocks.

9. The apparatus of claim 8, wherein the transform process is Multiple Transform Selection (MTS).

10. The apparatus of claim 8, wherein the transform process is a Low Frequency Non-Separable Transform (LFNST).

11. The device according to claims 1 to 10, wherein the device is a wireless transmit / receive unit.

12. The device according to claims 1 to 10, wherein the device is a video decoder.

13. The apparatus of claims 1 to 10, further comprising a computing memory communicatively coupled to the processor.

14. A decoding method, the method comprising: Obtain video data; Determining a chrominance block from the video data; determining, based on the video data, that a direct mode (DM) applies to the chroma block; retrieving data associated with a luma block associated with the chroma block based on a determination that the DM applies to the chroma block, the data associated with the luma block indicating a prediction process; as well as The prediction process is applied to the chroma block.

15. The method according to claim 14, The determining that DM is applied to the chroma block comprises determining that DM is applied to the chroma block based on a flag in the video data.

16. The method according to claim 14, The prediction process includes decoding-end intra mode derivation (DIMD).

17. The method according to claim 14, The prediction process includes template-based intra mode derivation (TIMD).

18. The method according to claim 14, The prediction process includes intra-frame template matching prediction (IntraTMP).

19. The method according to claim 14, The prediction process described is the Spatial Geometric Prediction Mode (SGPM).

20. The method according to claim 14, The prediction process includes multiple reference line (MRL) prediction.

21. The method according to claim 14, further comprising: retrieving data associated with the luma block indicating a transform process based on the determination that DM applies to the chroma block; as well as The transform process is applied to the chroma blocks.

22. The method of claim 21, wherein the transform process is Multiple Transform Selection (MTS).

23. The method of claim 21, wherein the transform process is a Low Frequency Non-Separable Transform (LFNST).

24. A computer readable medium comprising instructions for causing one or more processors to perform the method according to any one of claims 14 to 23.

25. A coding device, comprising: A processor, the processor being configured to: determining to decrypt a chrominance block using a prediction process associated with a luma block, the luma block being associated with the chrominance block; generating an indication that a direct mode (DM) applies to the chroma block; generating video data comprising the chrominance block, the indication that DM applies to the chrominance block, the luma block, and data indicating that the luma block is associated with the prediction process; as well as The video data is transmitted.

26. The apparatus of claim 25, wherein the indication that DM applies to the chroma block comprises a flag.

27. The device according to claim 25, The prediction process includes decoding-end intra mode derivation (DIMD).

28. The device according to claim 25, The prediction process includes template-based intra mode derivation (TIMD).

29. The device according to claim 25, The prediction process includes intra-frame template matching prediction (IntraTMP).

30. The device according to claim 25, The prediction process includes spatial geometric prediction mode (SGPM) prediction.

31. The device according to claim 25, The prediction process includes multiple reference line (MRL) prediction.

32. The device according to claim 25, The video data further comprises data indicating that the luminance block is associated with a transform process.

33. The apparatus of claim 32, wherein the transform process is Multiple Transform Selection (MTS).

34. The apparatus of claim 32, wherein the transform process is a Low Frequency Non-Separable Transform (LFNST).

35. The device according to claims 25 to 34, wherein the device is a wireless transmit / receive unit.

36. The device of claims 25 to 34, wherein the device is a video decoder.

37. The apparatus of claims 25 to 34, further comprising a computing memory communicatively coupled to the processor.

38. A method of encoding, the method comprising: determining to decrypt a chrominance block using a prediction process associated with a luma block, the luma block being associated with the chrominance block; generating an indication that a direct mode (DM) applies to the chroma block; generating video data comprising the chrominance block, the indication that DM applies to the chrominance block, the luma block, and data indicating that the luma block is associated with the prediction process; as well as The video data is transmitted.

39. The method of claim 38, wherein the indication that DM applies to the chroma block comprises a flag.

40. The method according to claim 38, The prediction process includes decoding-end intra mode derivation (DIMD).

41. The method according to claim 38, The prediction process includes template-based intra mode derivation (TIMD).

42. The method according to claim 38, The prediction process includes intra-frame template matching prediction (IntraTMP).

43. The method according to claim 38, The prediction process includes spatial geometric prediction mode (SGPM) prediction.

44. The method according to claim 38, The prediction process includes multiple reference line (MRL) prediction.

45. The method according to claim 38, The video data further comprises data indicating that the luminance block is associated with a transform process.

46. ​​The method of claim 45, wherein the transform process is Multiple Transform Selection (MTS).

47. The method of claim 45, wherein the transform process is a Low Frequency Non-Separable Transform (LFNST).

48. An electromagnetic signal carrying computer readable instructions for performing the method according to any one of claims 38 to 47.

49. A computer readable medium comprising instructions for causing one or more processors to perform the method of any one of claims 38 to 47.

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