Chroma multiple transform selection

Abstract

Systems, methods, and tools are disclosed for performing chroma multiple transform selection (MTS). The MTS may be enabled for one or more chroma components associated with a video block or video block data. The device may determine a transform index associated with performing MTS on the chroma component. A decoder may obtain video block data. The decoder may determine that the MTS is for one or more chroma components associated with the video block data. The decoder may perform an inverse transform on the chroma component associated with the video block data using MTS, e.g., to generate chroma prediction residual data. The decoder may decode the video block data based on the chroma prediction residual data. The encoder may be configured to determine the MTS for a chroma component associated with the video block. The encoder may perform a transform on the one or more chroma components associated with the video block using the MTS.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of European Patent Application No. 22305970.0 filed on July 1, 2022, the contents of which are incorporated herein by reference in their entirety. 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. Video coding systems may include, for example, block-based, wavelet-based, and / or object-based systems. Summary of the invention

[0004] Disclosed are systems, methods, and tools for performing chroma multiple transform selection (MTS). MTS may be enabled for one or more chroma components associated with a video block or video block data. A device (e.g., a decoder and / or an encoder) may be configured to determine a transform index associated with performing MTS on one or more chroma components (e.g., a chroma block). A decoder may be configured to obtain video block data. A decoder may be configured to determine that MTS is used for one or more chroma components associated with the video block data. A decoder may be configured to perform an inverse transform on one or more chroma components associated with the video block data using MTS, for example to generate chroma prediction residual data. A decoder may be configured to decode the video block data based on the chroma prediction residual data. An encoder may be configured to obtain a video block. An encoder may be configured to determine that MTS is used for one or more chroma components associated with a video block. An encoder may be configured to perform a transform on one or more chroma components associated with a video block using MTS. An encoder may be configured to encode a video block.

[0005] For example, an MTS transform index (e.g., chroma transform index) for a chroma component may be obtained based on an implicit MTS. For example, an MTS transform index (e.g., chroma transform index) for a chroma component may be obtained based on a luma transform index. The chroma transform index may be the same as a luma transform index for a luma block (e.g., component) associated with the chroma block (e.g., chroma component). The chroma transform index may be derived based on the luma transform index.

[0006] Certain intra prediction modes may affect MTS. For example, an intra prediction mode (e.g., cross component linear model (CCLM), multi-model linear model (MMLM), chroma fusion, etc.) may be determined for a coding block. Signaling of a chroma transform index may be suppressed. The device may determine a chroma transform index independently of a luma transform index, for example, based on a determined intra prediction mode and / or based on not receiving a chroma transform index in video data. The device may determine to perform implicit MTS on a chroma block, for example, based on a determined intra prediction mode and / or based on a chroma transform index in video data that is not received. The device may determine to use a default transform, for example, based on a determined intra prediction mode and / or based on a chroma transform index in video data that is not received.

[0007] Inter-component transform (ICT) may affect MTS. For example, a device may determine whether ICT is used for a coding block. A device may receive an MTS index indication associated with a chroma block. For example, if ICT is enabled, the MTS index indication may be a (e.g., a single, unique) MTS index indication (e.g., a flag). For example, if ICT is not enabled, the MTS index indication may include a first MTS index indication and a second MTS index indication (e.g., separate flags for different chroma components).

[0008] The systems, methods, and means described herein may relate to decoders. In some examples, the systems, methods, and means described herein may relate to encoders. In some examples, the systems, methods, and means described herein may relate to 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 one or more processors to perform the methods described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented.

[0010] Figure 1B is an example of a method that can be used according to an embodiment of the present invention. Figure 1A A system diagram of an example wireless transmit / receive unit (WTRU) for use within the illustrated communication system.

[0011] 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 illustrated communication system.

[0012] Figure 1D is an example of a method that can be used according to an embodiment of the present invention. Figure 1A System diagram of another example RAN and another example CN used within the illustrated communication system.

[0013] Figure 2 An example video encoder is illustrated.

[0014] Figure 3 An example video decoder is illustrated.

[0015] Figure 4 Examples of systems in which various aspects and examples may be implemented are illustrated.

[0016] Figure 6 An example decoder-based MTS performed on chroma components is illustrated.

[0017] Figure 7 An example encoder-based MTS performed on chroma components is illustrated. DETAILED DESCRIPTION

[0018] A more detailed understanding may be obtained from the following description given by way of example in conjunction with the accompanying drawings.

[0019] Figure 1A 1 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.

[0020] like Figure 1AAs 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.

[0021] 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. Although the base stations 114a, 114b are each depicted as a single element, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0022] 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 one 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.

[0023] 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).

[0024] 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).

[0025] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-APro).

[0026] 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).

[0027] In one 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 used 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).

[0028] 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.

[0029] Figure 1AThe 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 one 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.

[0030] 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, delay 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, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level 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, delay requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. Figure 1A Although 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, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0031] The CN 106 / 115 may also act 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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 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 one 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.

[0036] 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.

[0037] 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.

[0038] 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).

[0039] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0040] 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.

[0041] 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.

[0042] The WTRU 102 may include a full-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with 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 one embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with specific subframes for UL (e.g., for transmission) or downlink (e.g., for reception)) may be concurrent and / or simultaneous.

[0043] 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.

[0044] 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.

[0045] 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 the UL and / or DL, etc. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0046] 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.

[0047] 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.

[0048] 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 an inter-evolved Node-B handover, 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] In a representative embodiment, the other network 112 may be a WLAN.

[0053] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for a 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 out of 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 target outside the BSS may be transmitted to the AP to be delivered to the corresponding target. 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 target STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Point-to-point traffic may be transmitted between the source STA and the target STA (e.g., directly between them) using a direct link setup (DLS). 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.

[0054] When using the 802.11ac infrastructure operation mode or a similar operation mode, the AP may send a beacon 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 a working 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 sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0055] 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.

[0056] 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 sending STA. At the receiver of the receiving STA, the above-mentioned operation for 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0057] 802.11af and 802.11ah support operating modes below 1 GHz. 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).

[0058] 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 operation 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 operation 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 operation mode) is sending to the AP, the entire available band may be considered busy even if most of the band remains idle and may be available.

[0059] 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.

[0060] Figure 1D1 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.

[0061] 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 one embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In one embodiment, the gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNB 180a and gNB 180b (and / or gNB 180c).

[0062] 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 transmit time intervals (TTIs) of varying or scalable lengths (e.g., containing different numbers of OFDM symbols and / or continuously varying absolute time lengths).

[0063] 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.

[0064] Each of the gNBs 180a, 180b, 180c may be associated with a specific 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.

[0065] 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 the CN operator.

[0066] 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, and / or 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.

[0067] 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 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.

[0068] 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.

[0069] 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 UPFs 184a, 184b via the N3 interfaces to the UPFs 184a, 184b and the N6 interfaces between the UPFs 184a, 184b and the DNs 185a, 185b.

[0070] 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.

[0071] 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.

[0072] 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 lab 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 RF circuits (e.g., which can include one or more antennas) can be used by the simulation device to send and / or receive data.

[0073] 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 characteristics, 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.

[0074] The aspects described and contemplated in this application can be implemented in many different forms. Figures 5 to 7 Some examples may be provided, but others are also contemplated. Figures 5 to 7 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.

[0075] In this application, the terms "reconstruction" and "decoding" may be used interchangeably, the terms "pixel" and "sample" may be used interchangeably, and the terms "image", "picture" and "frame" may be used interchangeably.

[0076] Various methods are described herein, and each method in the 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.

[0077] like Figure 2 and Figure 3 As shown, various methods and other aspects described in this application can be used to modify modules (e.g., decoding modules) of video encoder 200 and decoder 300. 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.

[0078] Various numerical values ​​are used in the examples described in this application. These and other specific values ​​are for the purpose of describing the examples, and the aspects are not limited to these specific values.

[0079] Figure 2 2 is a schematic diagram illustrating an example video encoder. Variations of the example encoder 200 are contemplated, but the following describes encoder 200 for clarity without describing all contemplated variations.

[0080] Before being encoded, the video sequence may undergo pre-encoding processing (201), such as 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 attached to the bitstream.

[0081] In encoder 200, a picture is encoded by encoder elements as described below. 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). In inter mode, motion estimation (275) and compensation (270) are performed. 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.

[0082] 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 both the transform and quantization, i.e., directly code the residual without applying the transform or quantization process.

[0083] 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).

[0084] Figure 3 is a schematic diagram illustrating an example of a video decoder. In the example decoder 300, the bitstream is decoded by the decoder elements as described below. 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.

[0085] Specifically, 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 can divide (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 can 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).

[0086] The decoded picture may also undergo post-decoding processing (385), such as an inverse color transform (e.g., conversion from YCbCr 4:2:0 to RGB 4:4:4) or performing an inverse remapping that is the inverse of the remapping process 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.

[0087] Figure 4 4 is a schematic 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 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 dedicated input ports and / or output ports. In various examples, system 400 is configured to implement one or more aspects of the aspects described in this document.

[0088] 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 removable and non-removable storage devices), and / or a network-accessible storage device.

[0089] 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. In addition, 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] In various examples, the input device of frame 445 has the corresponding input processing element associated as known in the art.For example, the RF part can be associated with the element suitable for the following: (i) select the required frequency (also referred to as selecting signal, or limiting the signal band to a band), (ii) down-convert the selected signal, (iii) again band-limit to narrower band to select the signal band that (for example) can be called channel in some examples, (iv) demodulate the signal through down-conversion and band-limited, (v) perform error correction, and / or (vi) demultiplex to select the required data packet stream. The RF part of various examples includes one or more elements for performing these functions, such as frequency selector, signal selector, band limiter, channel selector, filter, down-converter, demodulator, error corrector and demultiplexer. The RF part can include a tuner that performs various functions in these functions, including, for example, down-converting the received signal to a lower frequency (for example, intermediate frequency or 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.

[0094] 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 stream as needed for presentation on the output device.

[0095] The various components of system 400 may be disposed within an integrated housing. Within the integrated housing, the various components may be interconnected and transmit data between the components using a suitable connection arrangement 425 (e.g., an internal bus known in the art, including an inter-chip (I2C) bus, wiring, and a printed circuit board).

[0096] 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.

[0097] In various examples, data is streamed or otherwise provided to the system 400 using a wireless network, such as a Wi-Fi network, e.g., 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. Additionally, various examples use wireless networks other than Wi-Fi, such as cellular networks or network.

[0098] 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.

[0099] In various examples, control signals are communicated 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.

[0100] 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.

[0101] 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. As a non-limiting example, processor 410 may be of any type suitable for the technical environment and may include one or more of a microprocessor, a general-purpose computer, a special-purpose computer, and a processor based on a multi-core architecture.

[0102] Various implementations involve decoding. As used in this application, "decoding" may encompass, for example, all or part of a process performed on a received coded sequence to produce a final output suitable for display. In various examples, such processes include one or more of the processes typically performed by a decoder, such as entropy decoding, inverse quantization, inverse transform, and differential decoding. In various examples, such processes also include or additionally include processes performed by a decoder of various implementations described in this application, such as determining a multiple transform selection (MTS) for one or more chroma components associated with video block data, performing an inverse transform on one or more chroma components associated with the video block data using the MTS to generate chroma prediction residual data, decoding the video block data based on the chroma prediction residual data, and the like.

[0103] 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 refer specifically to a subset of operations or 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.

[0104] Various implementations involve encoding. In a manner similar to the discussion above regarding "decoding", "encoding" as used in this application may 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 partitioning, differential encoding, transforms, quantization, and entropy encoding. In various examples, such processes also include or additionally include processes performed by encoders of various implementations described in this application, such as determining an MTS for one or more chroma components associated with a video block, performing a transform on one or more chroma components associated with a video block using the MTS, and the like.

[0105] 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 encoding 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.

[0106] Note that as used herein, syntax elements (e.g., coding syntax for transform index, MTS_CU_flag, MTS_Hor_flag, MTS_Ver_flag, MTS_CU_flag_chroma, MTS_Hor_flag_chroma, MTS_Ver_flag_chroma, etc.) are descriptive terms. Therefore, they do not exclude the use of other syntax element names.

[0107] 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.

[0108] The specific implementations and aspects described herein may be implemented in, for example, a method or process, a device, a software program, a data stream, or a signal. Even if only discussed 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., a device or program). The device 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 equipment, such as, for example, a computer, a mobile phone, a portable / personal digital assistant ("PDA"), and other equipment that facilitates information communication between end users.

[0109] 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.

[0110] Additionally, the present application may involve "determining" various pieces of information. Determining information may include, for example, one or more of estimating information, calculating information, predicting information, or retrieving information from a memory. Obtaining may include receiving, retrieving, constructing, generating, and / or determining.

[0111] 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.

[0112] 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.

[0113] 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 selecting only the second listed option (B), or selecting 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 selecting only the second listed option (B), or selecting only the third listed option (C), or selecting only the first listed option and the second listed option (A and B), or selecting only the first listed option and the third listed option (A and C), or selecting only the second listed option and the third listed option (B and C), or selecting all three options (A and B and C). This can be extended to as many items as listed, as would be apparent to one of ordinary skill in the art and related arts.

[0114] Moreover, as used herein, the word "signaling" especially refers to indicating something to a corresponding decoder. Thus, in an example, the same parameters are used at both the encoder and decoder ends. Therefore, for example, the encoder may send (explicit signaling) specific parameters to the decoder so that the decoder may 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. By avoiding sending any actual function, bit saving is achieved in various examples. It should be understood that signaling can be implemented in a variety of ways. For example, in various examples, one or more grammatical elements, flags, etc. are used to signal information to the corresponding decoder. Although the verb form "signaling" of the word is previously related to, the word may also be used as a noun "signal" herein.

[0115] 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 specific implementations. For example, a signal may be formatted to carry a bit stream of the example. 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.

[0116] 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 in the embodiments. 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) a result 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.

[0117] Disclosed are systems, methods, and tools for performing chroma multiple transform selection (MTS). MTS may be enabled for one or more chroma components associated with a video block or video block data. A device (e.g., a decoder and / or an encoder) may be configured to determine a transform index associated with performing MTS on one or more chroma components (e.g., a chroma block). A decoder may be configured to obtain video block data. A decoder may be configured to determine that MTS is used for one or more chroma components associated with the video block data. A decoder may be configured to perform an inverse transform on one or more chroma components associated with the video block data using MTS, for example to generate chroma prediction residual data. A decoder may be configured to decode the video block data based on the chroma prediction residual data. An encoder may be configured to obtain a video block. An encoder may be configured to determine that MTS is used for one or more chroma components associated with a video block. An encoder may be configured to perform a transform on one or more chroma components associated with a video block using MTS. An encoder may be configured to encode a video block.

[0118] For example, an MTS transform index (e.g., chroma transform index) for a chroma component may be obtained based on an implicit MTS. For example, an MTS transform index (e.g., chroma transform index) for a chroma component may be obtained based on a luma transform index. The chroma transform index may be the same as a luma transform index for a luma block (e.g., component) associated with the chroma block (e.g., chroma component). The chroma transform index may be derived based on the luma transform index.

[0119] Certain intra prediction modes may affect MTS. For example, an intra prediction mode (e.g., cross component linear model (CCLM), multi-model linear model (MMLM), chroma fusion, etc.) may be determined for a coding block. Signaling of a chroma transform index may be suppressed. The device may determine a chroma transform index independently of a luma transform index, for example, based on a determined intra prediction mode and / or based on not receiving a chroma transform index in video data. The device may determine to perform implicit MTS on a chroma block, for example, based on a determined intra prediction mode and / or based on a chroma transform index in video data that is not received. The device may determine to use a default transform, for example, based on a determined intra prediction mode and / or based on a chroma transform index in video data that is not received.

[0120] Inter-component transform (ICT) may affect MTS. For example, a device may determine whether ICT is used for a coding block. A device may receive an MTS index indication associated with a chroma block. For example, if ICT is enabled, the MTS index indication may be a (e.g., a single, unique) MTS index indication (e.g., a flag). For example, if ICT is not enabled, the MTS index indication may include a first MTS index indication and a second MTS index indication (e.g., separate flags for different chroma components).

[0121] The systems, methods, and means described herein may relate to decoders. In some examples, the systems, methods, and means described herein may relate to encoders. In some examples, the systems, methods, and means described herein may relate to 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 one or more processors to perform the methods described herein.

[0122] Transform coding associated with chroma components may be performed. Multiple transform selection (MTS) may be enabled for chroma components and / or may be enabled for luma components. Specific adaptation of MTS may be provided (eg, as described herein).

[0123] Multiple transform selections may be performed. MTS may also be used, for example, for residual coding of inter- and / or intra-coded blocks (e.g., in addition to DCT-II). MTS may use (e.g., multiple) selected transforms, e.g., from DCT8 / DST7. Transform matrices may include DST-VII and DCT-VIII.

[0124] Table 1 illustrates example basis functions of selected DST / DCT.

[0125]

[0126] Table 1

[0127] The transform matrix may be quantized (e.g., more accurately than a transform matrix in a different application), e.g., to maintain orthogonality of the transform matrix. The coefficients (e.g., all coefficients) may have 10 bits, e.g., to keep (e.g., intermediate) values ​​of the transformed coefficients (e.g., after a horizontal transform and after a vertical transform) within a 16-bit range.

[0128] An enabling indication (e.g., a separate enabling indication, a separate MTS flag) may be specified at the SPS level (e.g., separately) for intra and inter, e.g., to control the MTS scheme. For example, if MTS is enabled at the SPS (e.g., when so), an indication (e.g., a CU level flag) may be signaled (e.g., to indicate whether MTS is applied). MTS may be applied (e.g., only) to luma. For example, MTS signaling may be skipped if one or more of the following conditions apply (e.g., when so): the position of the last (e.g., significant) coefficient of a luma transform block (TB) is less than 1 (e.g., DC only); and / or the last (e.g., significant) coefficient of a luma TB is located inside an MTS return-to-zero region.

[0129] DCT2 may be applied, for example, in multiple directions. (For example, if the MTS CU flag is equal to zero), DCT2 may be applied, for example, in two directions based on the MTS CU flag. For example, if the MTS CU flag is equal to one, other flags (e.g., two other flags) may be (e.g., additionally) signaled (e.g., to indicate the transform types for the horizontal and vertical directions, respectively). Table 2 illustrates an example transform and signaling mapping table. For example, the transform selection for ISP and implicit MTS may be used (e.g., unified) by removing intra mode and block shape dependencies. For example, if the current block is in ISP mode or if the current block is an intra block and both intra explicit MTS and inter explicit MTS are enabled (e.g., turned on), DST7 may be used for (e.g., only for) both horizontal and vertical transform kernels. An 8-bit main transform kernel may be used, for example, for transform matrix precision. The transform kernels used (e.g., all transform kernels) can be kept the same, for example, including 4-point DCT-2 and DST-7, 8-point, 16-point, and 32-point DCT-2. Other transform kernels (e.g., including 64-point DCT-2, 4-point DCT-8, 8-point, 16-point, 32-point DST-7, and DCT-8) can use an 8-bit main transform kernel.

[0130]

[0131] Table 2

[0132] High frequency transform coefficients may be zeroed. High frequency transform coefficients may be zeroed for DST-7 blocks and DCT-8 blocks of size (e.g., width, height, or both) equal to 32, e.g., to reduce complexity of large-size DST-7 and DCT-8. Coefficients within the 16x16 lower frequency region may be retained (e.g., only coefficients within the 16x16 lower frequency region).

[0133] The residual of the block may be coded using a transform skip mode. For example, if the CU level MTS_CU_flag is not equal to zero (e.g., when such) (e.g., to avoid redundancy of syntax coding), signaling of the transform skip flag may be suppressed (e.g., not signaled). For example, if LFNST or MIP is activated for the current CU (e.g., when such), the implicit MTS transform may be set to the default transform (e.g., DCT2). For example, if MTS is enabled for an inter-coded block (e.g., when such), implicit MTS may be enabled.

[0134] Execute and / or enable MTS.

[0135] In some examples, DST7 and DCT8 transform cores (eg, only DST7 and DCT8 transform cores) may be utilized (eg, for MTS), such as may be used for intra- and inter-coding.

[0136] A main transform (e.g., an additional main transform) may be employed. The main transform may include DCT5, DST4, DST1 and / or an identity transform (IDT). The MTS set may depend on (e.g., be dependent on) a TU size and / or intra-frame mode information. Different TU sizes (e.g., 16 different TU sizes) may be considered. For (e.g., each) TU size, for example, depending on the intra-frame mode information, a plurality of different (e.g., 5 different) categories may be considered. For (e.g., each) category, a plurality of (e.g., 1, 4, or 6) different transform pairs may be considered. For example, depending on the sum of the absolute values ​​of the transform coefficients, a plurality of intra-frame MTS candidates may be adaptively selected (e.g., between 1, 4, and 6 MTS candidates). For example, the sum may be compared with a threshold (e.g., two fixed thresholds) to determine the (e.g., total) number of allowed MTS candidates. For example, the number of allowed MTS candidates may be determined based on one or more of the following thresholds: 1 candidate: sum<=th0; 4 candidates: th0<sum<=th1; and 6 candidates: sum>th1.

[0137] Multiple categories may be considered (e.g., a total of 80 different categories may be considered). Some of those different categories may (e.g., often) share transform sets (e.g., identical transform sets). The number of unique entries that may exist in the resulting LUT (e.g., 58) is less than the total number of different categories (e.g., less than 80).

[0138] In an example (e.g., for an angular mode), joint symmetry on TU shape and intra prediction may be considered. Mode i (e.g., i>34) with TU shape A×B may be mapped to (e.g., the same) category corresponding to mode j=(68−i) with TU shape B×A. The order of the horizontal and vertical transform kernels may be swapped, for example, for (e.g., each) transform pair. For example, for a 16×4 block with mode 18 (e.g., horizontal prediction) and a 4×16 block with mode 50 (e.g., vertical prediction), the blocks may be mapped to the same category (e.g., where the vertical and horizontal transform kernels are swapped). In an example (e.g., for a wide-angle mode), the (e.g., nearest) conventional angular mode may be used for transform set determination. For example, mode 2 may be used for (e.g., all) modes between -2 and -14. Similarly, mode 66 may be used for modes 67 to 80.

[0139] Chroma prediction modes may be provided and / or enabled.Intra prediction for chroma components may be performed in conventional intra prediction (eg, planar, DC, or angular) and / or in a cross-component prediction model (CCLM), where luma samples may be used as predictions for chroma components.

[0140] For example, a prediction mode using chroma decoder side intra mode derivation (DIMD) may be used. For example, chroma DIMD may be an extension of luma DIMD, where a template surrounding a chroma block (e.g., Cb and Cr components) may be analyzed (e.g., in addition to the collocated luma block) to obtain the directionality of the residual, and the intra mode may be derived (e.g., thereby).

[0141] For example, a prediction mode using an extended CCLM with a multi-model linear model (MLMM) may be used (e.g., where 2 CCLM models are derived using a threshold separating the two models). For example, depending on the pixel value, (e.g., one) portion of the prediction signal may be generated from a first mode and a second portion may be generated from another model.

[0142] For example, prediction may be performed using chroma fusion. Prediction for chroma may include combining conventional intra mode with MMLM mode.

[0143] A joint residual coding mode (eg, JointCbCr) may be used. If a joint residual coding mode is used (eg, when such), the residuals of the chroma components (eg, Cb and Cr) may be coded together, and a single residual may be signaled in the bitstream.

[0144] MTS may be enabled for chroma components (e.g., chroma blocks associated with a coding block). It may be determined that MTS is performed on chroma components. For example, MTS transform indices may be used to perform MTS on chroma components. In an example, an MTS transform pair (e.g., MTS transform index) for a chroma component may be determined (e.g., obtained) based on a luma MTS transform pair. Figure 5 An example of juxtaposed luminance components and chrominance components is shown. Figure 5 As shown, the luma transform index may be used to determine the collocated chroma components. In an example, the MTS transform pairs for the chroma components may be the same as the luma MTS transform pairs.

[0145] For example, the (e.g., same) process used to derive transform pairs for luma components may be used to derive transform pairs for chroma components (e.g., chroma transform indices may be derived based on luma transform indices, such as Figure 5 ). A transform index syntax element may be signaled, for example, to indicate which of a transform pair may be used (e.g., for chroma components). The indication may be signaled at the CU level (e.g., similar to the transform pairs signaled for luma components) or at other levels (e.g., PU, ​​TU).

[0146] In an example, the same indication used to indicate the transform pair to be used for the luma component may be used for the chroma components. The CU level indication (e.g., flag) for MTS may be used for both the luma component and the chroma components. The method may also be used for (e.g., limited) single tree coding, e.g., because the same tree may be shared between luma and chroma components (e.g., so a single indication may be used (e.g., required) to indicate which transform index to use).

[0147] In some examples, separate indications may be signaled for luma and chroma components (e.g., cb and cr). Separate indications may provide (e.g., high) flexibility for selecting different transforms for different components. For example, Table 3 illustrates an example transform and signaling mapping table for chroma components.

[0148]

[0149] Table 3

[0150] In an example, the MTS list for chroma may be modified by the selected MTS for the luma component. For example, the MTS selected for the luma component (e.g., from the MTS list for the luma component, such as, for example, Table 2) may be placed as the first transform in the chroma MTS list (e.g., at the row in Table 3 where MTS_Hor_flag_chroma=0 and MTS_Ver_flag_chroma=0). For example, if there is a good correlation between the luma transform and the chroma transform (e.g., when this is the case), signaling may be reduced (e.g., only 0,0 is signaled).

[0151] In an example, if the MTS selected for the luma component is placed as the first transform in the chroma MTS list (e.g., when so), the other transform pairs in the chroma MTS list may be shifted down in the MTS list. For example (e.g., with respect to Table 2), if the transform pairs DST7 and DCT8 are selected for horizontal and vertical, respectively, for the luma component, the chroma MTS list may be modified by placing DST7 and DCT8 at a row where MTS_Hor_flag_chroma is 0 and MTS_Ver_flag_chroma is 0. Thus, the transform pairs where DST7 is used for horizontal and DST7 is used for vertical may be shifted to a row where MTS_Hor_flag_chroma is 0 and MTS_Ver_flag_chroma is 1, and the transform pairs where DCT8 is used for horizontal and DST7 is used for vertical may be shifted to a row where MTS_Hor_flag_chroma is 1 and MTS_Ver_flag_chroma is 0. For example (e.g., with respect to Table 3), if transform pairs DST7 and DCT8 are selected for horizontal and vertical, respectively, for the luma component, the chroma MTS list may swap transform pairs in which MTS_Hor_flag_chroma is 0 and MTS_Ver_flag_chroma is 0 (e.g., transform pairs DST7 for horizontal and DST7 for vertical), so the chroma MTS list may have transform pairs DST7 and DCT8 for horizontal at rows in which MTS_Hor_flag_chroma is 0 and MTS_Ver_flag_chroma is 0, and may have transform pairs DST7 for horizontal and DST7 for vertical at rows in which MTS_Hor_flag_chroma is 1 and MTS_Ver_flag_chroma is 0. Other transform pairs in the chroma MTS list may remain unchanged (e.g., rows where MTS_Hor_flag_chroma is 0 and MTS_Ver_flag_chroma is 1 are still mapped to transform pairs DCT8 for horizontal and DCT7 for vertical, and rows where MTS_Hor_flag_chroma is 1 and MTS_Ver_flag_chroma is 1 are still mapped to DCT8 for horizontal and DCT8 for vertical).

[0152] The procedure (eg, as described herein) can be extended to dual tree coding. For example, the MTS of the luma component can be obtained at the collocated CU at the upper left corner of the chroma block. In an example, the value can be obtained at the center of the block.

[0153] For example, implicit MTS may be enabled and / or performed, for example, for chroma components. For example, implicit MTS may be performed according to equations 1 and 2:

[0154] trTypeHor = (nTbW ≥ 4 && nTbW ≤ 16) ? DST7 : DCT2 Equation 1

[0155] trTypeVer = (nTbH ≥ 4 && nTbH ≤ 16) ? DST7 : DCT2 Equation 2

[0156] For example, an implicit transform selection may be used instead of signaling an indication describing a selected chroma transform pair. For a chroma block, a transform pair may be derived as a transform pair corresponding to an implicit MTS. The implicit MTS may include, for example, determining an MTS transform index (e.g., an MTS chroma transform index) associated with one or more chroma components based on a block width and / or a block height associated with a video block. For example, a chroma transform index (e.g., an MTS transform index) may be obtained based on performing an implicit MTS, for example, where a transform or inverse transform using the MTS is performed using the chroma transform index. Using an implicit MTS may reduce complexity (e.g., encoder complexity), for example, because an RD search may be suppressed from being performed (e.g., not required) at the encoder side to obtain a (e.g., optimal) transform index, and signaling may also be suppressed from being performed (e.g., may not be required) to describe a selected transform pair.

[0157] Specific modes may also be used for MTS (eg, in addition to other procedures as described herein).

[0158] The chroma intra prediction mode (e.g., future chroma intra prediction mode) may be distinguished from luma intra prediction modes, such as, for example, CCLM / MMLM and / or chroma fusion. An intra prediction mode for a coding block may be determined. The intra prediction mode may affect the MTS transform and the MTS inverse transform performed on the chroma component. For example, whether to obtain a chroma transform index (e.g., an MTS transform index) may be determined based on the determined intra prediction mode.

[0159] In some modes (e.g., CCLM / MMLM and / or chroma fusion), luma-to-chroma prediction may be used. The residual signals corresponding to those signals may be distinguished from the residual signals generated by conventional intra prediction. The transform designs for these residuals may be different (e.g., may not follow the transform design for luma). For example, if the transform design for the residuals from the luma component is different from the residuals from the chroma components, one or more of the following may be performed: if the chroma component is decoded with CCLM / MMLM or chroma fusion mode, signaling of the transform index may be suppressed (e.g., may not be signaled), and a default transform may be used (e.g., DCT-II); if the chroma component is decoded with CCLM / MMLM or chroma fusion mode, signaling of the transform index may be suppressed (e.g., may not be signaled), and an implicit MTS may be used. The chroma transform index may be determined independently of the luma transform index.

[0160] In an example, (e.g., in the special case of ICT) an inter-component transform may be performed. An inter-component transform (ICT) may include, for example, a pre-transform that may use (e.g., exploit) the correlation between Cb and Cr color components. In an example (e.g., on the encoder side), for a given pair of a Cb coding block (CB) and a Cr CB to be encoded, once a Cb residual generated by subtracting a prediction of the Cb CB from an original Cb CB and a Cr residual generated by subtracting a prediction of the Cr CB from an original Cr CB are obtained, ICT may include applying a rotation transform to the two residuals, for example, which may produce (e.g., a single) ICT residual. The (e.g., single) ICT residue may be further encoded, for example, by applying DCT2-DCT2. In an example (e.g., on the decoder side), for a given pair of a Cb CB and a Cr CB to be decoded, once a single reconstructed residual is obtained, an inverse ICT may be applied thereto, for example, which may produce a reconstructed Cb residual and a reconstructed Cr residual.

[0161] The video device may determine whether ICT is used for a coding block. For example, an indication of whether to perform ICT may be signaled. For example, if ICT is selected as a current pair of encoding / decoding a Cb coding block (CB) and a Cr CB (e.g., when such), then (e.g., a unique, single, one) MTS indication (e.g., an MTS index indication) may be signaled for encoding / decoding of the Cb component and the Cr component (e.g., one MTS index indication for both the first chroma block and the second chroma block). In an example, for example, if ICT is suppressed for (e.g., not selected for) encoding / decoding a current pair of Cb CB and Cr CB (e.g., a first MTS index indication may be used for the first chroma block, and a second MTS index indication may be used for the second chroma block) (e.g., when such), then multiple (e.g., two separate) MTS flags may be signaled for encoding / decoding of the Cb component and the Cr component. This may enable (e.g., provide) flexibility for selecting (e.g., optimal) MTS transforms for each chroma component, for example, while disabling this high flexibility when ICT is selected.

[0162] Figure 6 An example decoder-based MTS performed on chroma components is illustrated. Figure 6 As shown at 610 in FIG. , video block data may be obtained. Figure 6 As shown at 620 in FIG. 1 , an MTS may be determined for one or more chrominance components associated with the video block data. Figure 6 As shown at 630 in FIG. 1 , an MTS may be used to perform an inverse transform on one or more chroma components associated with the video block data, for example, to generate chroma prediction residual data. Figure 6 As shown at 640 in FIG. , the video block data may be decoded, for example, based on the chroma prediction residual data.

[0163] Figure 7 An example encoder-based MTS performed on chroma components is illustrated. As shown at 710, a video block may be obtained. Figure 7 As shown at 720 in FIG. 1 , an MTS may be determined for one or more chrominance components associated with a video block. Figure 7 As shown at 730 in FIG. 1 , MTS may be used to perform a transform on one or more chrominance components associated with a video block. Figure 7 As shown at 740 in FIG. , the video blocks may be encoded.

[0164] In an example, a medium (such as video data) may include information associated with performing MTS on chroma components. A bitstream may include information associated with performing MTS on chroma components. Video data and / or a bitstream may include information (e.g., for transmission). Video data and / or a bitstream may be generated by a device (e.g., an encoding device and / or a decoding device). Video data and / or a bitstream may be stored and / or accessed, e.g., for MTS on chroma components. Video data and / or a bitstream may be sent (e.g., to a decoder), e.g., for MTS on chroma components. Video data and / or a bitstream may or may not be sent.

[0165] Although the features and elements are described above in particular 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 video decoding device, the video decoding device comprising: A processor, the processor being configured to: determining a multiple transform select (MTS) for a chroma block associated with the video block data; performing an inverse transform on the chroma block associated with the video block data using the MTS to generate chroma prediction residual data; as well as The video block data is decoded based on the chroma prediction residual data.

2. The video decoding device according to claim 1, wherein the processor is further configured to: A chroma transform index is obtained based on a luma transform index associated with a luma block corresponding to the chroma block, wherein the inverse transform using the MTS is performed using the chroma transform index. 3 . The video decoding device according to claim 2 , wherein the chrominance transform index obtained based on the luma transform index is the same as the luma transform index. 4 . The video decoding apparatus according to claim 2 , wherein the chrominance transform index obtained based on the luma transform index is derived based on the luma transform index.

5. The video decoding device according to claim 1, wherein the processor is further configured to: A chroma transform index is obtained based on an implicit MTS, wherein the inverse transform using the MTS is performed using the chroma transform index.

6. The video decoding device of claim 1 , wherein the chrominance block is associated with a coding block, and wherein the processor is further configured to: determining an intra prediction mode to be used for the coding block; and A determination is made based on the intra prediction mode whether to obtain a chroma transform index based on a luma transform index associated with the coding block.

7. The video decoding apparatus of claim 6 , wherein the chroma transform index is determined independently of a luma transform index based on that the intra prediction mode to be used for the coding block is associated with one of a cross-component linear model (CCLM), a multi-model linear model (MMLM), or chroma fusion.

8. The video decoding device according to claim 6, wherein the processor is further configured to: Based on the intra prediction mode to be used for the coding block being associated with one of a cross-component linear model (CCLM), a multi-model linear model (MMLM), or chroma fusion, it is determined to perform implicit MTS on the chroma block.

9. The video decoding device of claim 1 , wherein the chroma block is a first chroma block associated with a first coding block, and wherein the processor is further configured to: determining an intra prediction mode to be used for a second coding block associated with a second chroma block; determining whether MTS is enabled for the second chroma block based on the intra prediction mode to be used for the second coding block, wherein MTS is determined to be disabled for the second chroma block based on the intra prediction mode to be used for the second coding block being associated with one of a cross-component linear model (CCLM), a multi-model linear model (MMLM), or chroma fusion; and An inverse transform is performed on the second chroma block based on a default transform.

10. The video decoding device of claim 1, wherein the chroma block is a first chroma block associated with a coding block, and wherein the processor is further configured to: determining whether ICT is used for the decoding block; and Based on a determination that ICT is used for the coded block, an MTS index indication associated with the first chroma block and a second chroma block is received, wherein the inverse transform using MTS is performed based on the MTS index indication.

11. The video decoding device according to claim 10, wherein the processor is further configured to: Based on a determination that ICT is suppressed for the decoding block, receiving a first MTS index indication and a second MTS index indication, wherein the first MTS index indication is associated with the first chroma block, wherein the second MTS index indication is associated with the second chroma block, and wherein the inverse transform performed on the first chroma block using MTS is performed based on the first MTS index indication; and Inverse transform is performed on the second chroma block using MTS based on the second MTS index indication.

12. A video encoding device, the video encoding device comprising: A processor, the processor being configured to: determining a multiple transform select (MTS) for a chroma block associated with the video block data; performing a transform on the chroma block associated with the video block data using the MTS to generate chroma prediction residual data; The video block data is encoded based on the chroma prediction residual data.

13. The video encoding device according to claim 12, wherein the processor is further configured to: A chroma transform index is determined based on a luma transform index associated with a luma block corresponding to the chroma block, wherein the transform performed on the chroma block using the MTS is performed using the chroma transform index. 14 . The video encoding apparatus according to claim 13 , wherein the transform index determined based on the luma transform index is the same as the luma transform index. 15 . The video encoding apparatus of claim 13 , wherein the transform index determined based on the luma transform index is implicitly derived from the luma transform index.

16. The video encoding device according to claim 12, wherein the processor is further configured to: A chroma transform index is obtained based on an implicit MTS, wherein the inverse transform using the MTS is performed using the chroma transform index.

17. The video encoding device of claim 12, wherein the chroma block is associated with a coding block, and wherein the processor is further configured to: determining an intra prediction mode to be used for the coding block; and A determination is made based on the intra prediction mode whether to obtain a chroma transform index based on a luma transform index associated with the coding block.

18. The video encoding apparatus of claim 17, wherein the chroma transform index is determined independently of a luma transform index based on that the intra prediction mode to be used for the coding block is associated with one of a cross-component linear model (CCLM), a multi-model linear model (MMLM), or chroma fusion.

19. The video encoding device according to claim 12, wherein the processor is further configured to: Based on the intra prediction mode to be used for the coding block being associated with one of a cross-component linear model (CCLM), a multi-model linear model (MMLM), or chroma fusion, it is determined to perform implicit MTS on the chroma block.

20. The video encoding device of claim 12, wherein the chroma block is a first chroma block associated with a first decoding block, and wherein the processor is further configured to: determining an intra prediction mode to be used for a second coding block associated with a second chroma block; determining whether MTS is enabled for the second chroma block based on the intra prediction mode to be used for the second coding block, wherein MTS is determined to be disabled for the second chroma block based on the intra prediction mode to be used for the second coding block being associated with one of a cross-component linear model (CCLM), a multi-model linear model (MMLM), or chroma fusion; and A transform is performed on the second chroma block based on a default transform.

21. The video encoding device of claim 12, wherein the chroma block is a first chroma block associated with a coding block, and wherein the processor is further configured to: determining whether ICT is used for the decoding block; and Based on the determination that the ICT is used for the decoding block, an MTS index indication associated with the first chroma block and the second chroma block is included in the video data, wherein the transformation using the MTS is performed based on the MTS index indication.

22. The video encoding device according to claim 21, wherein the processor is further configured to: Based on a determination that ICT is suppressed for the decoding block, including in the video data a first MTS index indication and a second MTS index indication, wherein the first MTS index indication is associated with the first chroma block, wherein the second MTS index indication is associated with the second chroma block, and wherein the transform performed on the first chroma block using MTS is performed based on the first MTS index indication; and A transform is performed on the second chroma block using the MTS based on the second MTS index indication.

23. A video decoding device, the video decoding device comprising: A processor, the processor being configured to: determining a multiple transform select (MTS) for a chroma block associated with the video block data; performing an inverse transform on the chroma block associated with the video block data using the MTS to generate chroma prediction residual data; as well as The video block data is decoded based on the chroma prediction residual data.

24. The video decoding device according to claim 23, wherein the processor is further configured to: A chroma transform index is obtained based on a luma transform index associated with a luma block corresponding to the chroma block, wherein the inverse transform using the MTS is performed using the chroma transform index. 25 . The video decoding apparatus according to claim 24 , wherein the chroma transform index obtained based on the luma transform index is the same as the luma transform index.

26. The video decoding apparatus according to claim 24, wherein the chrominance transform index obtained based on the luma transform index is derived based on the luma transform index.

27. The video decoding device according to claim 23, wherein the processor is further configured to: A chroma transform index is obtained based on an implicit MTS, wherein the inverse transform using the MTS is performed using the chroma transform index.

28. The video decoding device of claim 23, wherein the chroma block is associated with a coding block, and wherein the processor is further configured to: determining an intra prediction mode to be used for the coding block; and A determination is made based on the intra prediction mode whether to obtain a chroma transform index based on a luma transform index associated with the coding block.

29. The video decoding apparatus of claim 28, wherein the chroma transform index is determined independently of a luma transform index based on that the intra prediction mode to be used for the coding block is associated with one of a cross-component linear model (CCLM), a multi-model linear model (MMLM), or chroma fusion.

30. The video decoding device according to claim 28, wherein the processor is further configured to: Based on the intra prediction mode to be used for the coding block being associated with one of a cross-component linear model (CCLM), a multi-model linear model (MMLM), or chroma fusion, it is determined to perform implicit MTS on the chroma block.

31. The video decoding device of claim 23, wherein the chroma block is a first chroma block associated with a first coding block, and wherein the processor is further configured to: determining an intra prediction mode to be used for a second coding block associated with a second chroma block; determining whether MTS is enabled for the second chroma block based on the intra prediction mode to be used for the second coding block, wherein MTS is determined to be disabled for the second chroma block based on the intra prediction mode to be used for the second coding block being associated with one of a cross-component linear model (CCLM), a multi-model linear model (MMLM), or chroma fusion; and An inverse transform is performed on the second chroma block based on a default transform.

32. The video decoding device of claim 23, wherein the chroma block is a first chroma block associated with a coding block, and wherein the processor is further configured to: determining whether ICT is used for the decoding block; and Based on a determination that ICT is used for the coded block, an MTS index indication associated with the first chroma block and a second chroma block is received, wherein the inverse transform using MTS is performed based on the MTS index indication.

33. The video decoding device according to claim 32, wherein the processor is further configured to: Based on a determination that ICT is suppressed for the decoding block, receiving a first MTS index indication and a second MTS index indication, wherein the first MTS index indication is associated with the first chroma block, wherein the second MTS index indication is associated with the second chroma block, and wherein the inverse transform performed on the first chroma block using MTS is performed based on the first MTS index indication; and Inverse transform is performed on the second chroma block using MTS based on the second MTS index indication.

34. A video encoding device, the video encoding device comprising: A processor, the processor being configured to: determining a multiple transform select (MTS) for a chroma block associated with the video block data; performing a transform on the chroma block associated with the video block data using the MTS to generate chroma prediction residual data; The video block data is encoded based on the chroma prediction residual data.

35. The video encoding device of claim 34, wherein the processor is further configured to: A chroma transform index is determined based on a luma transform index associated with a luma block corresponding to the chroma block, wherein the transform performed on the chroma block using the MTS is performed using the chroma transform index.

36. The video encoding apparatus of claim 35, wherein the transform index determined based on the luma transform index is the same as the luma transform index.

37. The video encoding apparatus of claim 35, wherein the transform index determined based on the luma transform index is implicitly derived from the luma transform index.

38. The video encoding device of claim 34, wherein the processor is further configured to: A chroma transform index is obtained based on an implicit MTS, wherein the inverse transform using the MTS is performed using the chroma transform index.

39. The video encoding device of claim 34, wherein the chroma blocks are associated with coding blocks, and wherein the processor is further configured to: determining an intra prediction mode to be used for the coding block; and A determination is made based on the intra prediction mode whether to obtain a chroma transform index based on a luma transform index associated with the coding block.

40. The video encoding apparatus of claim 39, wherein the chroma transform index is determined independently of a luma transform index based on that the intra prediction mode to be used for the coding block is associated with one of a cross-component linear model (CCLM), a multi-model linear model (MMLM), or chroma fusion.

41. The video encoding device of claim 34, wherein the processor is further configured to: Based on the intra prediction mode to be used for the coding block being associated with one of a cross-component linear model (CCLM), a multi-model linear model (MMLM), or chroma fusion, it is determined to perform implicit MTS on the chroma block.

42. The video encoding device of claim 34, wherein the chroma block is a first chroma block associated with a first coding block, and wherein the processor is further configured to: determining an intra prediction mode to be used for a second coding block associated with a second chroma block; determining whether MTS is enabled for the second chroma block based on the intra prediction mode to be used for the second coding block, wherein MTS is determined to be disabled for the second chroma block based on the intra prediction mode to be used for the second coding block being associated with one of a cross-component linear model (CCLM), a multi-model linear model (MMLM), or chroma fusion; and A transform is performed on the second chroma block based on a default transform.

43. The video encoding device of claim 34, wherein the chroma block is a first chroma block associated with a coding block, and wherein the processor is further configured to: determining whether ICT is used for the decoding block; and Based on the determination that the ICT is used for the decoding block, an MTS index indication associated with the first chroma block and the second chroma block is included in the video data, wherein the transformation using the MTS is performed based on the MTS index indication.

44. The video encoding device of claim 43, wherein the processor is further configured to: Based on a determination that ICT is suppressed for the decoding block, including in the video data a first MTS index indication and a second MTS index indication, wherein the first MTS index indication is associated with the first chroma block, wherein the second MTS index indication is associated with the second chroma block, and wherein the transform performed on the first chroma block using MTS is performed based on the first MTS index indication; and A transform is performed on the second chroma block using the MTS based on the second MTS index indication.

45. A computer readable medium comprising instructions for causing one or more processors to perform the method of any one of claims 23 to 44.

46. ​​A device, comprising: The device according to any one of claims 1 to 22; as well as At least one of: (i) an antenna configured to receive a signal, the signal comprising data representing an image; (ii) a band limiter configured to limit the received signal to a frequency band comprising the data representing the image; or (iii) a display configured to display the image.

47. Video data comprising data generated by the method according to any one of claims 34 to 44.

48. The device of any one of claims 1 to 22, wherein the device comprises a memory.

Images