Extended NSPT usage for enlarged block size

Abstract

Systems, methods, and instrumentation for the field of video compression are disclosed herein. In an example, a video encoding device may identify a residual block. The residual block may be associated with a primary transform index and a secondary transform index. The video encoding device may determine whether the secondary transform index is non-zero and whether an enlarged non-separable primary transform (NSPT) is allowed. Based on the secondary transform being non-zero and the enlarged NSPT being allowed, the video encoder may derive a reduced residual block size from a residual block size associated with the residual block, down-sample the residual block to the reduced residual block size, apply NSPT to the reduced residual block to obtain a transformed reduced block, and transform the transformed reduced block to the residual block. Quantization, transformation, and entropy coding of the transformed reduced block are performed. The primary transform index and the secondary transform index may be encoded.

Description

[0001] Cross-references to related applications This application claims the benefit of European Patent Application No. 23306116.7, filed on June 30, 2023, the disclosure of which is incorporated herein by reference in its entirety. Background Technology

[0002] Video coding systems can be used to compress digital video signals, for example, to reduce the storage and / or transmission bandwidth required for such signals. Video coding systems can include, for example, block-based, wavelet-based, and / or object-based systems. Summary of the Invention

[0003] This paper discloses systems, methods, and instruments associated with the use of extended NSPT for expanding block size.

[0004] In this example, a video encoding device can identify residual blocks. These residual blocks can be associated with a primary transform index and a secondary transform index. The video encoding device can determine whether the secondary transform index is non-zero and whether expanding the Inseparable Primary Transform (NSPT) is permitted. Based on the secondary transform being non-zero and expanding the NSPT being permitted for the residual block, the video encoder can derive a reduced residual block size from the residual block size associated with the residual block, downsample the residual block to the reduced residual block size, apply the NSPT to the reduced residual block to obtain a transformed reduced block, and perform quantization, transform, and entropy coding on the transformed reduced block. The primary transform index and the secondary transform index can be encoded.

[0005] In the example, the reduced residual block size may be associated with the largest region of the supported NSPT included in the residual region. In the example, downsampling of the residual block may use an interpolation filter. In the example, the upper-left region of the reduced residual block size may include coefficients transformed by the NSPT, and the remainder of the reduced residual block size may include zero coefficients. In the example, the primary and secondary transforms may be applied by the video coding device based on the secondary transform index being zero or the expansion of the Inseparable Primary Transform (NSPT) not being allowed for the residual block. In the example, allowing the expansion of the NSPT for the residual block may include applying the expansion of the NSPT to a block size of 32×4 or 4×32.

[0006] In this example, a video decoding device can decode the quantized coefficients of a residual block. The device can compare the scan position of the last significant coefficient in the residual block with a threshold. Based on the scan position of the last significant coefficient in the residual block being below the threshold, the secondary transform index and the primary transform index can be decoded. In this example, the threshold can be a scan position threshold associated with comparing the residual block size with a reduced block size. Based on the secondary transform index being non-zero and the expansion of the NSPT being allowed for the residual block, the device can derive a reduced NSPT block from the residual block, apply an inverse NSPT to the reduced NSPT block to obtain an NSPT-transformed sub-block, and convert (e.g., upsample) the NSPT-transformed sub-block to the size of the residual block.

[0007] In the example, applying the inverse NSPT to a reduced NSPT block size could mean applying the inverse NSPT to the upper left region of the reduced NSPT block size. In the example, the reduced NSPT block size from the residual block could be derived from the video decoding device based on (e.g., further based on) NSPTs that are not permitted for the residual block. In the example, the primary and secondary transforms can be applied by the video decoding device based on the secondary transform index being zero or the expanded non-separable primary transform (NSPT) being not permitted for the residual block. In the example, allowing the expanded NSPT for the residual block could include applying the expanded NSPT to a block size of 32×4 or 4×32.

[0008] These examples can be executed by a device having a processor. The device can be an encoder or a decoder. These examples can be executed by a computer program product stored on a non-transient computer-readable medium and comprising program code instructions. These examples can be executed by a computer program including program code instructions.

[0009] The systems, methods, and instruments described herein may relate to decoders. In some examples, the systems, methods, and instruments described herein may relate to encoders. In some examples, the systems, methods, and instruments described herein may relate to signals (e.g., from an encoder and / or received by a decoder). A computer-readable medium may include instructions for causing one or more processors to perform the methods described herein. A computer program product may include instructions that, when executed by one or more processors, cause the one or more processors to implement the methods described herein. Attached Figure Description

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

[0011] Figure 1B The illustration shows a device that can be used according to one embodiment. Figure 1A The diagram shows a system diagram of an example wireless transmit / receive unit (WTRU) used in a communication system.

[0012] Figure 1C The illustration shows a device that can be used according to one embodiment. Figure 1A The diagram shows a system diagram of an example radio access network (RAN) and an example core network (CN) used in a communication system.

[0013] Figure 1D The illustration shows a device that can be used according to one embodiment. Figure 1A The diagram shows a system diagram of a further example RAN and a further example CN used within the communication system.

[0014] Figure 2 The illustration shows a sample video encoder.

[0015] Figure 3 The illustration shows an example video decoder.

[0016] Figure 4 The illustration shows an example of a system that can implement various aspects and examples.

[0017] Figure 5 The illustration shows an example of ROI for LFNST16.

[0018] Figure 6 The illustration shows an example of ROI for LFNST8.

[0019] Figure 7 The illustration shows an example NSPT in which a single inseparable transformation replaces a two-stage transformation (DCT2-LFNST).

[0020] Figure 8 An example of the residual coding process is illustrated.

[0021] Figure 9 An example of the residual decoding process is illustrated.

[0022] Figure 10 The illustration shows an example block residual coding process using the extended NSPT process.

[0023] Figure 11 The illustration shows an example of a transform block derived from downsampling.

[0024] Figure 12 The illustration shows an example block residual decoding process using the extended NSPT procedure. Detailed Implementation

[0025] A more detailed understanding can be obtained from the following description, which is given in conjunction with the accompanying drawings as examples.

[0026] Figure 1A This diagram illustrates an example communication system 100 in which one or more of the disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content (such as voice, data, video, messaging, broadcasting, etc.) to multiple wireless users. The communication system 100 enables multiple wireless users to access such content by sharing 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 Extended OFDM (ZT UW DTS-s OFDM), Unique Word OFDM (UW-OFDM), Resource Block Filtered OFDM, Filter Bank Multicarrier (FBMC), etc.

[0027] like Figure 1A As shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, Public Switched Telephone Network (PSTN) 108, Internet 110, and other networks 112. Although it will be appreciated, the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, and 102d can be any type of device configured to operate and / or communicate in a wireless environment. As an example, WTRUs 102a, 102b, 102c, and 102d (any of which may be referred to as a “station” and / or “STA”) may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain scenarios), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. Any of WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0028] The communication system 100 may also include base station 114a and / or base station 114b. Each of base stations 114a and 114b may be any type of device configured to wirelessly interface with at least one of WTRUs 102a, 102b, 102c, and 102d to facilitate access to one or more communication networks, such as CN 106 / 115, the Internet 110, and / or other networks 112. As an example, base stations 114a and 114b may be any of a base transceiver station (BTS), Node-B, eNode B, home node B, home eNode B, gNB, NR NodeB, site controller, access point (AP), wireless router, etc. Although base stations 114a and 114b are depicted as single elements, it will be understood that base stations 114a and 114b may include any number of interconnected base stations and / or network elements.

[0029] Base station 114a may be part of RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as base station controllers (BSCs), radio network controllers (RNCs), relay nodes, etc. Base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies, which may be referred to as cells (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a specific geographic area for a radio service, which may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Therefore, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology, and multiple transceivers may be used for each sector of the cell. For example, beamforming can be used to transmit and / or receive signals in a desired spatial direction.

[0030] Base stations 114a and 114b can communicate with one or more of WTRUs 102a, 102b, 102c, and 102d via air interface 116, which can be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, millimeter wave, infrared (IR), ultraviolet (UV), visible light, etc.). Air interface 116 can be established using any suitable radio access technology (RAT).

[0031] More specifically, as noted above, communication system 100 can be a multiple access system and can employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, base station 114a in RAN 104 / 113, and WTRUs 102a, 102b, and 102c can implement radio technologies such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which can use Wideband CDMA (WCDMA) to establish air interfaces 115 / 116 / 117. WCDMA can include communication protocols such as High-Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA can include High-Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High-Speed ​​UL Packet Access (HSUPA).

[0032] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c can implement radio technologies such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which can use Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-A Pro) to establish air interface 116.

[0033] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c can implement radio technologies such as NR radio access, which can use a new radio (NR) to establish an air interface 116.

[0034] In one embodiment, base station 114a and WTRUs 102a, 102b, and 102c can implement multiple radio access technologies. For example, base station 114a and WTRUs 102a, 102b, and 102c can jointly implement LTE radio access and NR radio access, for example, using the dual connectivity (DC) principle. Therefore, the air interface utilized by WTRUs 102a, 102b, and 102c can be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., eNBs and gNBs).

[0035] In other embodiments, base station 114a and WTRUs 102a, 102b, 102c can implement the following radio technologies, such as IEEE 802.11 (i.e., WiFi), IEEE 802.16 (i.e., WiMAX), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Provisional Standard 2000 (IS-2000), Provisional Standard 95 (IS-95), Provisional Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data Rate GSM Evolution (EDGE), GSMEDGE (GERAN), etc.

[0036] Figure 1A Base station 114b can be, for example, a wireless router, a home node B, a home eNode B, or an access point, and can utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a commercial area, home, vehicle, campus, industrial facility, air corridor (e.g., for drone use), road, etc. In one embodiment, base station 114b and WTRUs 102c, 102d can implement radio technologies such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, base station 114b and WTRUs 102c, 102d can implement radio technologies such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, base station 114b and WTRUs 102c, 102d can utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or femtocell. Figure 1A As shown, base station 114b may have a direct connection to Internet 110. Therefore, base station 114b may not be required to access Internet 110 via CN 106 / 115.

[0037] RAN 104 / 113 can communicate with CN 106 / 115, which can be any type of network configured to provide voice, data, application, and / or Voice over Internet Protocol (VoIP) services to one or more of WTRUs 102a, 102b, 102c, and 102d. Data may have different Quality of Service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. CN 106 / 115 can provide call control, billing services, location-based services, prepaid calling, internet connectivity, video distribution, etc., and / or perform advanced security functions, such as user authentication. Although... Figure 1AAlthough not shown, it will be understood that RAN104 / 113 and / or CN 106 / 115 can communicate directly or indirectly with other RANs that use the same RAT as RAN 104 / 113 or a different RAT. For example, in addition to being connected to RAN 104 / 113, which can utilize NR radio technology, CN106 / 115 can also communicate with another RAN (not shown) that uses GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0038] CN 106 / 115 may also act as a gateway for WTRU 102a, 102b, 102c, 102d to access PSTN 108, the Internet 110, and / or other networks 112. PSTN 108 may include a circuit-switched telephone network providing Common Old-Style Telephone Service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices using common communication protocols such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) from the TCP / IP Internet Protocol suite. Network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, network 112 may include another CN connected to one or more RANs, which may use the same RAT as RAN 104 / 113 or a different RAT.

[0039] Some or all of the WTRUs 102a, 102b, 102c, and 102d in communication system 100 may include multi-mode capabilities (e.g., WTRUs 102a, 102b, 102c, and 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). For example, Figure 1A The WTRU 102c shown can be configured to communicate with a base station 114a that can use cellular-based radio technology and a base station 114b that can use IEEE 802 radio technology.

[0040] Figure 1B This is a system diagram illustrating example WTRU 102. (Example:) Figure 1B As shown, WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power supply 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138, etc. It will be appreciated that WTRU 102 may include any sub-combination of the above-described elements while remaining consistent with the embodiments.

[0041] Processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple 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. As implied above, processor 118 may include multiple processors. Processor 118 may perform signal encoding, data processing, power control, input / output processing, and / or any other function that enables WTRU 102 to operate in a wireless environment. Processor 118 may be coupled to transceiver 120, which may be coupled to transmitting / receiving element 122. Although Figure 1B The processor 118 and transceiver 120 are depicted as separate components, but it will be understood that the processor 118 and transceiver 120 can be integrated together in an electronic package or chip.

[0042] Transmitting / receiving element 122 can be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) via air interface 116. For example, in one embodiment, transmitting / receiving element 122 can be an antenna configured to transmit and / or receive RF signals. In one embodiment, transmitting / receiving element 122 can be a transmitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In yet another embodiment, transmitting / receiving element 122 can be configured to transmit and / or receive both RF and optical signals. It will be appreciated that transmitting / receiving element 122 can be configured to transmit and / or receive any combination of wireless signals.

[0043] Although the transmitting / receiving element 122 is in Figure 1B While depicted as a single element, WTRU 102 may include any number of transmitting / receiving elements 122. More specifically, WTRU 102 may employ MIMO technology. Thus, in one embodiment, WTRU 102 may include two or more transmitting / receiving elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals via air interface 116.

[0044] Transceiver 120 can be configured to modulate signals to be transmitted by transmitting / receiving element 122 and demodulate signals received by transmitting / receiving element 122. As noted above, WTRU 102 can have multi-mode capability. Thus, for example, transceiver 120 may include multiple transceivers for enabling WTRU 102 to communicate via multiple RATs (such as NR and IEEE 802.11).

[0045] The processor 118 of WTRU 102 can be coupled to the speaker / microphone 124, keypad 126, and / or display / touchpad 128 (e.g., a liquid crystal display (LCD) unit or an organic light-emitting diode (OLED) display unit), and can receive user input data from them. The processor 118 can also output user data to the speaker / microphone 124, keypad 126, and / or display / touchpad 128. Additionally, the processor 118 can access information from any type of suitable memory (such as non-removable memory 130 and / or removable memory 132), and store data in that memory. Non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), hard disk, or any other type of memory storage device. Removable memory 132 may include a subscriber identity module (SIM) card, memory stick, secure digital storage (SD) card, etc. In other embodiments, processor 118 may access information from memory that is not physically located on WTRU 102 (such as on a server or home computer (not shown)) and store data in that memory.

[0046] The processor 118 can receive power from the power supply 134 and can be configured to distribute and / or control the power going to other components in the WTRU 102. The power supply 134 can be any suitable device for powering the WTRU 102. For example, the power supply 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.

[0047] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) about the current location of the WTRU 102. In addition to, or instead of, information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) via 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 understood that the WTRU 102 may acquire location information using any suitable location determination method, while remaining consistent with the embodiments.

[0048] The processor 118 may be further coupled to other peripherals 138, which may include one or more software and / or hardware modules providing additional features, functions, and / or wired or wireless connectivity. For example, peripherals 138 may include accelerometers, electronic compasses, satellite transceivers, digital cameras (for photos and / or videos), Universal Serial Bus (USB) ports, vibration devices, television transceivers, hands-free headsets, Bluetooth® modules, FM radio units, digital music players, media players, video game player modules, internet browsers, virtual reality and / or augmented reality (VR / AR) devices, activity trackers, etc. Peripherals 138 may include one or more sensors, which may be one or more of the following: gyroscopes, accelerometers, Hall effect sensors, magnetometers, orientation sensors, proximity sensors, temperature sensors, time sensors, geolocation sensors, altimeters, light sensors, touch sensors, magnetometers, barometers, gesture sensors, biometric sensors, and / or humidity sensors.

[0049] WTRU 102 may include a full-duplex radio, for which the transmission and reception of some or all signals (e.g., associated with specific subframes for both UL (e.g., for transmission) and downlink (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit to reduce and / or substantially eliminate self-interference via hardware (e.g., a choke) or via signal processing (e.g., a separate processor (not shown) or via processor 118). In one embodiment, WTRU 102 may include a half-duplex radio, for which the transmission and reception of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) or downlink (e.g., for reception)) may be concurrent and / or simultaneous.

[0050] Figure 1C The diagram illustrates a system diagram of RAN 104 and CN 106 according to an embodiment. As noted above, RAN 104 can employ E-UTRA radio technology to communicate with WTRUs 102a, 102b, and 102c via air interface 116. RAN 104 can also communicate with CN 106.

[0051] RAN 104 may include eNode-Bs 160a, 160b, and 160c, although it will be understood that RAN 104 may include any number of eNode-Bs while remaining consistent with the embodiments. eNode-Bs 160a, 160b, and 160c may each include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c via air interface 116. In one embodiment, eNode-Bs 160a, 160b, and 160c may implement MIMO technology. Therefore, eNode-B 160a may, for example, use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU 102a.

[0052] Each of the eNode-B 160a, 160b, and 160c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, and user scheduling in the UL and / or DL, etc. Figure 1C As shown, eNode-B 160a, 160b, and 160c can communicate with each other via the X2 interface.

[0053] Figure 1C The CN 106 shown may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) Gateway (or PGW) 166. Although each of the foregoing elements is depicted as part of CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than a CN operator.

[0054] The MME 162 can connect to each of the eNode-Bs 162a, 162b, and 162c in RAN 104 via the S1 interface and can act as a control node. For example, the MME 162 can be responsible for authenticating users of WTRUs 102a, 102b, and 102c, activating / deactivating bearers, and selecting a specific serving gateway during the initial attachment of WTRUs 102a, 102b, and 102c. The MME 162 can provide control plane functions for handover between RAN 104 and other RANs (not shown) employing other radio technologies, such as GSM and / or WCDMA.

[0055] The SGW 164 can connect to each of the eNode Bs 160a, 160b, and 160c in RAN 104 via the S1 interface. The SGW 164 can typically route and forward user data packets to / from WTRUs 102a, 102b, and 102c. The SGW 164 can perform other functions, such as anchoring the user plane during inter-eNode B handover, triggering paging when DL data is available for WTRUs 102a, 102b, and 102c, and managing and storing the context of WTRUs 102a, 102b, and 102c.

[0056] SGW 164 can be connected to PGW 166, which can provide WTRU 102a, 102b, 102c with access to a packet-switched network (such as Internet 110) to facilitate communication between WTRU 102a, 102b, 102c and IP-enabled devices.

[0057] CN 106 facilitates communication with other networks. For example, CN 106 can provide WTRUs 102a, 102b, and 102c with access to a circuit-switched network (such as PSTN 108) to facilitate communication between WTRUs 102a, 102b, and 102c and conventional terrestrial line communication equipment. For example, CN 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server), which acts as an interface between CN 106 and PSTN 108. Additionally, CN 106 can provide WTRUs 102a, 102b, and 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0058] Despite WTRU in Figures 1A-1D While described as a wireless terminal, it is envisioned that, in some representative embodiments, such a terminal may use (e.g., temporarily or permanently) a wired communication interface with a communication network.

[0059] In a representative embodiment, the other network 112 may be a WLAN.

[0060] In an Infrastructure Basic Services Set (BSS) mode, a WLAN may have an access point (AP) for the BSS and one or more stations (STAs) 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 into and / or out of the BSS. Traffic originating outside the BSS destined for a STA can be delivered to the STA via the AP. Traffic from a STA to a destination outside the BSS can be sent to the AP for delivery to the appropriate destination. Traffic between STAs within the BSS can be sent via the AP, for example, where a source STA can send traffic to the AP, and the AP can deliver the traffic to the destination STA. Traffic between STAs within the BSS can be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic can be sent between source and destination STAs (e.g., directly between them) using a direct link setup (DLS). In some representative embodiments, the DLS may use 802.11e DLS or 802.11z Tunneled DLS (TDLS). A WLAN using the Standalone BSS (IBSS) mode may not have an access point (AP), and STAs within or using the IBSS (e.g., all STAs) can communicate directly with each other. The IBSS communication mode may sometimes be referred to as a "self-organizing" communication mode in this document.

[0061] When using 802.11ac infrastructure operation mode or a similar operation mode, the AP can transmit beacons on a fixed channel, such as a primary channel. The primary channel can be of fixed width (e.g., a bandwidth of 20 MHz) or dynamically set via signaling. The primary channel can be the operating channel of the BSS and can be used by STAs to establish connections with the AP. In some representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) can be implemented, for example, in an 802.11 system. For CSMA / CA, STAs including the AP (e.g., each STA) can sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, that STA can back off. A STA (e.g., only one station) can transmit at any given time within a given BSS.

[0062] High-throughput (HT) STAs can communicate using a 40MHz wide channel, for example, by combining a primary 20MHz channel with adjacent or non-adjacent 20MHz channels to form a 40MHz wide channel.

[0063] Very High Throughput (VHT) STAs can support channels with widths of 20MHz, 40MHz, 80MHz, and / or 160MHz. 40MHz and / or 80MHz channels can be formed by combining consecutive 20MHz channels. A 160MHz channel can be formed by combining eight consecutive 20MHz channels or by combining two non-consecutive 80MHz channels (which can be referred to as an 80+80 configuration). For the 80+80 configuration, after channel coding, data is transmitted via a segment resolver that divides the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time-domain processing can be performed separately on each stream. The streams can be mapped onto two 80MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the above operations for the 80+80 configuration can be reversed, and the combined data can be sent to the Media Access Control (MAC).

[0064] Operating modes below 1 GHz are supported by 802.11af and 802.11ah. The channel operating bandwidth and carrier are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV white space (TVWS) spectrum, while 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to representative embodiments, 802.11ah can 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) certain and / or limited bandwidths. MTC devices may include batteries with a lifespan exceeding a threshold (e.g., to maintain a very long battery life).

[0065] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include a channel that can be designated as the primary channel. The primary channel can have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be set and / or limited by the STA that supports the minimum bandwidth operating mode among all STAs operating in the BSS. In the 802.11ah example, for STAs that support (e.g., only support) the 1MHz mode (e.g., MTC type devices), the primary channel can be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings can depend on the status of the primary channel. If the primary channel is busy, for example because an STA (which only supports the 1MHz operating mode) is transmitting to the AP, the entire available band may be considered busy, even if most of the band is still idle and could be available.

[0066] In the United States, the available frequency band for 802.11ah is from 902MHz to 928MHz. In South Korea, the available frequency band is from 917.5MHz to 923.5MHz. In Japan, the available frequency band is from 916.5MHz to 927.5MHz. Depending on the country code, the total available bandwidth for 802.11ah is 6MHz to 26MHz.

[0067] Figure 1D The diagram illustrates a system diagram of RAN 113 and CN 115 according to an embodiment. As noted above, RAN 113 may employ NR radio technology to communicate with WTRUs 102a, 102b, and 102c via air interface 116. RAN 113 may also communicate with CN 115.

[0068] RAN 113 may include gNBs 180a, 180b, and 180c, although it will be understood that RAN 113 may include any number of gNBs while remaining consistent with the embodiments. gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c via air interface 116. In one embodiment, gNBs 180a, 180b, and 180c may implement MIMO technology. For example, gNBs 180a and 180b may utilize beamforming to transmit signals to and / or receive signals from gNBs 180a, 180b, and 180c. Therefore, gNB 180a may, for example, use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU 102a. In one embodiment, gNBs 180a, 180b, and 180c can implement carrier aggregation technology. For example, gNB 180a can transmit multiple component carriers to WTRU 102a (not shown). A subset of these component carriers can be on unlicensed spectrum, while the remaining component carriers can be on licensed spectrum. In one embodiment, gNBs 180a, 180b, and 180c can implement Cooperative Multipoint (CoMP) technology. For example, WTRU 102a can receive cooperative transmissions from gNBs 180a and 180b (and / or gNB 180c).

[0069] WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using transmissions associated with scalable digitization. For example, OFDM symbol spacing and / or OFDM subcarrier spacing can vary depending on different transmissions, different cells, and / or different portions of the radio transmission spectrum. WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using subframes of various or scalable lengths or transmission time intervals (TTIs) (e.g., containing different numbers of OFDM symbols and / or absolute times of varying durations).

[0070] gNBs 180a, 180b, and 180c can be configured to communicate with WTRUs 102a, 102b, and 102c in standalone and / or non-standalone configurations. In standalone configuration, WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c without also accessing other RANs (e.g., eNode-Bs 160a, 160b, and 160c). In standalone configuration, WTRUs 102a, 102b, and 102c can utilize one or more of gNBs 180a, 180b, and 180c as mobility anchors. In standalone configuration, WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using signals in unlicensed frequency bands. In a non-standalone configuration, WTRUs 102a, 102b, and 102c can communicate with / connect to gNBs 180a, 180b, and 180c, and simultaneously communicate with / connect to another RAN (such as eNode-Bs 160a, 160b, and 160c). For example, WTRUs 102a, 102b, and 102c can implement DC principles to communicate substantially simultaneously with one or more gNBs 180a, 180b, and 180c and one or more eNode-Bs 160a, 160b, and 160c. In a non-standalone configuration, eNode-B 160a, 160b, and 160c can act as mobility anchors for WTRU 102a, 102b, and 102c, and gNB 180a, 180b, and 180c can provide additional coverage and / or throughput to serve WTRU 102a, 102b, and 102c.

[0071] Each of gNBs 180a, 180b, and 180c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and / or DL, network slicing support, dual connectivity, interoperability between NR and E-UTRA, routing of user plane data to User Plane Functions (UPF) 184a and 184b, routing of control plane information to Access and Mobility Management Functions (AMF) 182a and 182b, etc. Figure 1D As shown, gNB 180a, 180b, and 180c can communicate with each other via the Xn interface.

[0072] Figure 1DThe CN 115 shown may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. Although each of the foregoing elements is depicted as part of the CN 115, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0073] AMF 182a and 182b can connect to one or more of the gNBs 180a, 180b, and 180c in RAN 113 via the N2 interface and can act as control nodes. For example, AMF 182a and 182b can be responsible for authenticating users of WTRU 102a, 102b, and 102c, supporting network slicing (e.g., handling different PDU sessions with different requirements), selecting specific SMF183a and 183b, managing registration areas, terminating NAS signaling, mobility management, etc. Network slices can be used by AMF 182a and 182b to customize CN support for WTRU 102a, 102b, and 102c based on the service types utilized by WTRU 102a, 102b, and 102c. For example, different network slices can be built for different use cases, such as services that rely on Ultra Reliable Low Latency (URLLC) access, services that rely on Enhanced Massive Mobile Broadband (eMBB) access, and services for Machine Type Communication (MTC) access. AMF 162 can provide control plane functions for handover between RAN 113 and other RANs (not shown) employing other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0074] SMFs 183a and 183b can connect to AMFs 182a and 182b in CN 115 via the N11 interface. SMFs 183a and 183b can also connect to UPFs 184a and 184b in CN 115 via the N4 interface. SMFs 183a and 183b can select and control UPFs 184a and 184b, and configure traffic routing through UPFs 184a and 184b. SMFs 183a and 183b can perform other functions, such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, and providing downlink data notifications. PDU session types can be IP-based, non-IP-based, Ethernet-based, etc.

[0075] UPF 184a and 184b can connect to one or more of gNBs 180a, 180b, and 180c in RAN 113 via the N3 interface. These gNBs can provide WTRU 102a, 102b, and 102c with access to packet-switched networks (such as the Internet 110) to facilitate communication between WTRU 102a, 102b, 102c and IP-enabled devices. UPF 184a and 184b can 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, and providing mobility anchoring.

[0076] CN 115 can facilitate communication with other networks. For example, CN 115 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between CN 115 and PSTN 108. Additionally, CN 115 can provide WTRUs 102a, 102b, and 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, WTRUs 102a, 102b, and 102c can connect to local data networks (DNs) 185a and 185b via the N3 interface to UPFs 184a and 184b and the N6 interface between UPFs 184a and 184b and DNs 185a and 185b.

[0077] Given Figures 1A-1D as well as Figures 1A-1D The corresponding descriptions may be performed by one or more emulation devices (not shown) to perform one or more of the functions described herein with respect to one or more of the following: WTRU102a-d, base station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or one or more other devices described herein. An emulation device may be one or more devices configured to emulate one or more of the functions described herein. For example, an emulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0078] Simulation devices can be designed to perform tests on one or more other devices in a laboratory environment and / or a carrier network environment. For example, the one or more simulation devices can perform one or more or all of their functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices within the communication network. The one or more simulation devices can perform one or more or all of their functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. Simulation devices can be directly coupled to another device for testing purposes and / or can use over-the-air wireless communication to perform tests.

[0079] The 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 devices can be used in test scenarios in a test laboratory and / or in non-deployed (e.g., testing) wired and / or wireless communication networks to perform testing on one or more components. The one or more simulation devices can be test rigs. Direct RF coupling and / or wireless communication via RF circuitry (e.g., which may include one or more antennas) can be used by the simulation devices to transmit and / or receive data.

[0080] This application describes various aspects, including tools, features, examples, models, schemes, etc. Many of these aspects are described in detail and are often described in a way that may sound restrictive, at least to illustrate individual characteristics. However, this is for clarity of purpose and does not limit the application or scope of those aspects. Indeed, all the different aspects can be combined and interchanged to provide further aspects. Furthermore, this aspect can also be combined and interchanged with aspects described in earlier filings.

[0081] The aspects described and conceived in this application can be implemented in many different forms. Figures 5-12 Some examples can be provided, but other examples can be thought of. Figures 5-12 The discussion does not limit the breadth of implementation methods. At least one aspect generally relates to video encoding and decoding, and at least one other aspect generally relates to the transmission of a generated or encoded bitstream. These and other aspects can be implemented as methods, apparatus, computer-readable storage media having instructions stored thereon for encoding or decoding video data according to any of the described methods, and / or computer-readable storage media having bitstreams generated according to any of the described methods stored thereon.

[0082] In this application, the terms “reconstructed” and “decoded” may be used interchangeably, as may the terms “pixel” and “sample”, and may the terms “image”, “picture” and “frame” be used interchangeably.

[0083] This document describes various methods, each of which includes one or more steps or actions for implementing the described method. Unless a specific order of steps or actions is required for the proper operation of the method, the order and / or use of specific steps and / or actions may be modified or combined. Additionally, terms such as "first," "second," etc., may be used in various examples to modify elements, components, steps, operations, etc., such as, for example, "first decoding" and "second decoding." The use of such terms does not imply a sequence of operations unless specifically required. Thus, in this example, the first decoding need not be performed before the second decoding, but may occur, for example, before, during, or in the time period overlapping with the second decoding.

[0084] The various methods and other aspects described in this application can be used to modify, for example Figure 2 and Figure 3 The modules of the video encoder 200 and decoder 300 shown herein, for example, a decoding module. Furthermore, the subject matter disclosed herein can be applied, for example, to any type, format, or version of video encoding, whether or not described in a standard or recommendation, whether pre-existing or future-developed, and any extensions to such standards and recommendations. Unless otherwise indicated or technically excluded, the aspects described herein may be used individually or in combination.

[0085] Various numerical values, such as bits, bit depth, etc., are used in the examples described in this application. These and other specific values ​​are used for the purpose of describing the examples, and the aspects described are not limited to these specific values.

[0086] Figure 2 This is a diagram illustrating an example video encoder. Variations of the example encoder 200 can be conceived, but encoder 200 is described below for clarity without depicting all expected variations.

[0087] Before being encoded, the video sequence may undergo pre-encoding processing (201), such as applying color transformations to the input color image (e.g., a conversion from RGB 4:4:4 to YCbCr 4:2:0), or performing remapping of the input image components to obtain a more resilient signal distribution for compression (e.g., using histogram equalization with one of the color components). Metadata may be associated with preprocessing and attached to the bitstream.

[0088] In encoder 200, the image is encoded by encoder elements as described below. The image to be encoded is partitioned (202) and processed in units such as coding units (CUs). Each unit is encoded using, for example, an intra-frame or inter-frame mode. When a unit is encoded in an intra-frame mode, it performs intra-frame prediction (260). In an inter-frame mode, motion estimation (275) and compensation (270) are performed. The encoder determines (205) which of the intra-frame or inter-frame modes to use for encoding the unit and indicates the intra-frame / inter-frame decision by, for example, a prediction mode flag. The prediction residual is calculated, for example, by subtracting (210) the prediction block from the original image block.

[0089] The predicted residual is then transformed (225) and quantized (230). The quantized transform coefficients, motion vectors, and other syntax elements are entropy encoded (245) to output a bit stream. The encoder can skip the transform and apply the quantization directly to the untransformed residual signal. The encoder can bypass both the transform and quantization, i.e., encode the residual directly without applying the transform or quantization process.

[0090] The encoder decodes the encoded blocks to provide a reference for further prediction. The quantized transform coefficients are dequantized (240) and inverse transformed (250) to decode the prediction residuals. The decoded prediction residuals and the predicted blocks are combined (255) to reconstruct the image blocks. A loop filter (265) is applied to the reconstructed image to perform, for example, deblocking / SAO (sample adaptive offset) filtering to reduce coding artifacts. The filtered image is stored in a reference image buffer (280).

[0091] Figure 3 This is a diagram illustrating an example video decoder. In the example decoder 300, the bitstream is decoded by decoder elements, as described below. The video decoder 300 generally performs the same operations as... Figure 2 The encoding passes described herein are mutually decoded passes. Encoder 200 generally also performs video decoding as part of the encoding of video data.

[0092] Specifically, the input to the decoder includes a video bitstream, which can be generated by the video encoder 200. First, entropy decoding (330) is performed on the bitstream to obtain transform coefficients, motion vectors, and other encoded information. Image partitioning information indicates how the image should be partitioned. Therefore, the decoder can partition (335) the image based on the decoded image partitioning information. The transform coefficients are dequantized (340) and inverse transformed (350) to decode the prediction residuals. The decoded prediction residuals and the predicted blocks are combined (355) to reconstruct the image blocks. The predicted blocks (370) can be obtained from intra-frame prediction (360) or motion-compensated prediction (i.e., inter-frame prediction) (375). A loop filter (365) is applied to the reconstructed image. The filtered image is stored in a reference image buffer (380).

[0093] The decoded image can undergo further post-decoding processing (385), such as inverse color transformation (e.g., conversion from YCbCr 4:2:0 to RGB 4:4:4), or inverse remapping, performing the inverse operation of the remapping process performed in pre-encoding processing (201). Post-decoding processing can utilize metadata derived in pre-encoding processing and signaled in the bitstream. In one example, the decoded image (e.g., after the application of a loop filter (365) and / or after post-decoding processing (385) in the case of post-decoding processing) can be sent to a display device for presentation to a user.

[0094] Figure 4 This is a diagram illustrating examples of systems in which the various aspects and examples described herein can be implemented. System 400 may be embodied as a device including the various components described below and configured to perform one or more of the aspects described in this document. Examples of such devices include, but are not limited to, various electronic devices such as personal computers, laptop computers, smartphones, tablet computers, digital multimedia set-top boxes, digital television receivers, personal video recording systems, connected home appliances, and servers. Elements of system 400 may be embodied individually or in combination in a single integrated circuit (IC), multiple ICs, and / or discrete components. For example, in at least one example, the processing and encoder / decoder elements of system 400 are distributed across multiple ICs and / or discrete components. In various examples, 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 and / or output ports. In various examples, system 400 is configured to implement one or more of the aspects described in this document.

[0095] System 400 includes: at least one processor 410 configured to execute instructions loaded therein for implementing various aspects, such as those described in this document. Processor 410 may include embedded memory, input / output interfaces, and various other circuitry as known in the art. System 400 includes at least one memory 420 (e.g., a volatile memory device and / or a non-volatile memory device). System 400 includes: a storage device 440 which may include non-volatile memory and / or volatile memory, including but not limited to electrically erasable programmable read-only memory (EEPROM), read-only memory (ROM), programmable read-only memory (PROM), random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash memory, disk drives, and / or optical disk drives. Storage device 440 may include internal storage devices, attached storage devices (including removable and non-removable storage devices), and / or network-accessible storage devices, as non-limiting examples.

[0096] System 400 includes an encoder / decoder module 430 configured to, for example, process data to provide encoded or decoded video, and the encoder / decoder module 430 may include its own processor and memory. The encoder / decoder module 430 represents one or more modules that may be included in a device to perform encoding and / or decoding functions. It is well known that a device may include one or both encoding and decoding modules. Furthermore, the encoder / decoder module 430 may be implemented as a separate element of system 400, or may be incorporated into processor 410 as a combination of hardware and software as known to those skilled in the art.

[0097] Program code to be loaded onto processor 410 or encoder / decoder 430 to execute the various aspects described herein may be stored in storage device 440 and subsequently loaded onto memory 420 for execution by processor 410. According to various examples, one or more of processor 410, memory 420, storage device 440, and encoder / decoder module 430 may store one or more items of various kinds during the execution of the processes described herein. Such stored items may include, but are not limited to, input video, decoded video or portions of decoded video, bitstreams, matrices, variables, and intermediate or final results from the processing of equations, formulas, operations, and operational logic.

[0098] In some examples, the memory within processor 410 and / or encoder / decoder module 430 is used to store instructions and provide working memory for processing required during encoding or decoding. However, in other examples, external memory (e.g., processor 410 or encoder / decoder module 430) is used for one or more of these functions. External memory may be memory 420 and / or storage device 440, such as volatile memory and / or non-volatile flash memory. In several examples, external non-volatile flash memory is used to store, for example, the operating system of a television. In at least one example, fast external volatile memory, such as RAM, is used as working memory for video encoding and decoding operations.

[0099] Input to the components of system 400 can be provided through various input devices as indicated in box 445. Such input devices include, but are not limited to: (i) a radio frequency (RF) section that receives RF signals transmitted over the air, for example, by a broadcaster; (ii) component (COMP) input terminals (or a collection of COMP input terminals); (iii) a universal serial bus (USB) input terminal; and / or (iv) a high-definition multimedia interface (HDMI) input terminal. Figure 4 Other examples not shown include composite video.

[0100] In various examples, the input device of block 445 has associated corresponding input processing elements as known in the art. For example, the RF section may be associated with elements suitable for: (i) selecting a desired frequency (also referred to as selecting a signal or limiting a signal to a frequency band); (ii) down-converting the selected signal; (iii) further limiting the frequency band to a narrower band to select a signal band that may be referred to as a channel in some examples; (iv) demodulating the down-converted and band-limited signal; (v) performing error correction; and / or (vi) demultiplexing to select the desired stream of data packets. The RF section of various examples includes one or more elements to perform these functions, such as frequency selectors, signal selectors, band limiters, channel selectors, filters, downconverters, demodulators, error correctors, and demultiplexers. The RF section may include: a tuner that performs various of these functions, including, for example, down-converting a received signal to a lower frequency (e.g., intermediate frequency or near-baseband frequency) or to baseband. In one set-top box example, the RF section and its associated input processing elements receive RF signals transmitted over a wired (e.g., cable) medium and perform frequency selection by filtering, down-converting, and filtering again to the desired frequency band. Various examples rearrange the order of the components described above (and others), remove some of these components, and / or add other components that perform similar or different functions. Adding components may include inserting components between existing components, such as, for example, inserting amplifiers and analog-to-digital converters. In various examples, the RF section includes an antenna.

[0101] USB and / or HDMI endpoints may include corresponding interface processors for connecting system 400 to other electronic devices across USB and / or HDMI connections. It should be understood that various aspects of input processing, such as Reed-Solomon error correction, may be implemented, for example, within a separate input processing IC or, if necessary, within processor 410. Similarly, aspects of USB or HDMI interface processing may be implemented, either within a separate interface IC or, if necessary, within processor 410. The demodulated, error-corrected, and demultiplexed stream is provided to various processing elements, including, for example, processor 410 and encoder / decoder 430, which operate in conjunction with memory and storage elements to process the data stream as needed for presentation on an output device.

[0102] Various components of the system 400 can be provided within an integrated housing, in which the various components can be interconnected and data can be transmitted therebetween using a suitable connection arrangement 425, such as an internal bus as known in the art, including inter-IC (I2C) bus, wiring and printed circuit board.

[0103] System 400 includes a communication interface 450 that enables communication with other devices via a communication channel 460. The communication interface 450 may include, but is not limited to, a transceiver configured to transmit and receive data on the communication channel 460. The communication interface 450 may include, but is not limited to, a modem or network interface card (NIC), and the communication channel 460 may be implemented over, for example, wired and / or wireless media.

[0104] In various examples, data is streamed or otherwise provided to system 400 using a wireless network such as WiFi (e.g., IEEE 802.11 (IEEE refers to the Institute of Electrical and Electronics Engineers)). In these examples, the Wi-Fi signal is received on a communication channel 460 and a communication interface 450 adapted for Wi-Fi communication. The communication channel 460 in 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 over-the-top communications. Other examples use a set-top box that delivers data over an HDMI connection in input box 445 to provide streaming data to system 400. Still other examples use an RF connection in input box 445 to provide streaming data to system 400. As indicated 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 Bluetooth® networks.

[0105] System 400 can provide output signals to various output devices, including a display 475, a speaker 485, and other peripheral devices 495. Various examples of the display 475 include one or more of the following: for example, a touchscreen display, an organic light-emitting diode (OLED) display, a curved display, and / or a foldable display. The display 475 can be used in televisions, tablets, laptops, cellular phones (mobile phones), or other devices. The display 475 can also be integrated with other components (e.g., as in a smartphone) or separate (e.g., an external monitor for a laptop). In various examples, other peripheral devices 495 include one or more of a standalone digital video disc (or digital multifunction disc) (DVD, for both terms), a disc player, a stereo system, and / or a lighting system. Various examples utilize one or more peripheral devices 495 that provide functionality based on the output of system 400. For example, a disc player performs the function of playing the output of system 400.

[0106] In various examples, signaling such as AV is used to transmit control signals between system 400 and display 475, speaker 485, or other peripheral devices 495. Device-to-device control links, consumer electronics control (CEC), or other communication protocols are implemented with or without user intervention. Output devices can be communicatively coupled to system 400 via dedicated connections through corresponding interfaces 470, 480, and 490. Alternatively, output devices can be connected to system 400 via communication interface 450 using communication channel 460. Display 475 and speaker 485 can be integrated into a single unit with other components of system 400 in electronic devices such as, for example, televisions. In various examples, display interface 470 includes display drivers, such as, for example, timing controller (TCon) chips.

[0107] Display 475 and speaker 485 can alternatively be separated from one or more other components, for example, if the RF section of input 445 is part of a separate set-top box. In various examples where display 475 and speaker 485 are external components, output signals can be provided via dedicated output connections, including, for example, HDMI ports, USB ports, or COMP outputs.

[0108] The example can be implemented by computer software, hardware, or a combination of hardware and software, as implemented by processor 410. As a non-limiting example, the example can be implemented by one or more integrated circuits. As a non-limiting example, memory 420 can be of any type suitable for the technical environment and can be implemented using any suitable data storage technology, such as optical memory devices, magnetic memory devices, semiconductor-based memory devices, fixed memory, and removable memory. As a non-limiting example, processor 410 can be of any type suitable for the technical environment and can encompass one or more of microprocessors, general-purpose computers, special-purpose computers, and processors based on multi-core architectures.

[0109] Various implementations involve decoding. As used in this application, “decoding” can encompass all or part of a process performed, for example, on a received encoded sequence to produce a final output suitable for display. In various examples, such a process includes one or more processes typically performed by a decoder, such as entropy decoding, dequantization, inverse transform, and differential decoding. In various examples, such a process may also or alternatively include a process performed by a decoder of various implementations described in this application, such as: decoding the quantized coefficients of a residual block; comparing the scan position of the last significant coefficient in the residual block with a threshold; decoding the secondary transform index and the primary transform index based on the scan position of the last significant coefficient in the residual block being below the threshold; deriving a reduced NSPT block from the residual block based on the secondary transform index being non-zero and the expansion of the Inseparable Primary Transform (NSPT) being permitted for the residual block; applying the inverse NSPT to the reduced NSPT block to obtain an NSPT-transformed sub-block; and upsampling the NSPT-transformed sub-block to the size of the residual block, etc.

[0110] As further examples, in one example, "decoding" refers only to entropy decoding; in another example, "decoding" refers only to differential decoding; and in yet another example, "decoding" refers to a combination of entropy decoding and differential decoding. Whether the phrase "decoding process" is intended to specifically refer to a subset of operations or generally to a broader decoding process will be clear based on the specific context of the description and is considered to be well understood by those skilled in the art.

[0111] Various implementations involve encoding. In a manner similar to the above discussion of “decoding,” the term “encoding,” as used herein, can encompass all or part of a process performed, for example, on an input video sequence to produce an encoded bitstream. In various examples, such a process includes one or more processes typically performed by an encoder, such as partitioning, differential coding, transform, quantization, and entropy coding. In various examples, such a process may also or alternatively include processes performed by an encoder of various implementations described herein, such as: identifying residual blocks, wherein the residual blocks are associated with a primary transform index and a secondary transform index; determining whether the secondary transform index is non-zero and whether expanding the non-separable primary transform (NSPT) is permitted; deriving a reduced residual block size from the residual block size associated with the residual block based on the secondary transform being non-zero and expanding the NSPT being permitted; downsampling the residual block to the reduced residual block size; applying the NSPT to the reduced residual block to obtain a transformed reduced block; performing quantization, transform, and entropy coding on the transformed reduced block; and encoding the primary transform index and the secondary transform index, etc.

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

[0113] When a diagram is presented as a flowchart, it should be understood that it also provides a block diagram of the corresponding device. Similarly, when a diagram is presented as a block diagram, it should be understood that it also provides a flowchart of the corresponding method / process.

[0114] The implementations and aspects described herein can be implemented, for example, in methods or processes, apparatus, software programs, data streams, or signals. Even if discussed only in the context of a single form of implementation (e.g., discussed only as a method), the features in question can be implemented in other forms (e.g., apparatus or program). Apparatus can be implemented, for example, in appropriate hardware, software, and firmware. Methods can be implemented, for example, in a processor, where processor generally refers to a processing device, including, for example, a computer, microprocessor, integrated circuit, or programmable logic device. Processors also include communication devices, such as, for example, computers, cellular phones, portable / personal digital assistants (“PDAs”), and other devices that facilitate communication of information between end users.

[0115] References to “an example” or “an instance” or “an implementation” or “an implementation” and their variations mean that the specific feature, structure, characteristic, etc., described in connection with the example is included in at least one example. Therefore, the appearance of the phrase “in an example” or “in an instance” or “in an implementation” or “in an implementation” and any variations appearing throughout this application do not necessarily all refer to the same example.

[0116] Additionally, this application may refer to "determining" various pieces of information. Determining information may include one or more of the following: estimated information, calculated information, predicted information, or information retrieved from memory. Obtaining may include receiving, retrieving, constructing, generating, and / or determining.

[0117] Furthermore, this application may refer to "accessing" various pieces of information. Accessing information may include one or more of the following: receiving information, retrieving information (e.g., from memory), storing information, moving information, copying information, calculating information, determining information, predicting information, or estimating information.

[0118] Additionally, this application may refer to "receiving" various pieces of information. As with "access," "receiving" is intended to be a broad term. Receiving information may include one or more of, for example, accessing information or retrieving information (e.g., from memory). Further, "receiving" typically refers to actions performed during operation, such as, for example, storing information, processing information, transmitting information, moving information, copying information, erasing information, calculating information, determining information, predicting information, or estimating information.

[0119] It should be understood that the use of any of the following “ / ”, “and / or”, and “…at least one of” (e.g., in the cases of “A / B”, “A and / or B”, and “at least one of A and B”) is intended to cover the selection of only the first listed option (A), or only the second listed option (B), or the selection of both options (A and B). As a further example, in the cases of “A, B, and / or C” and “at least one of A, B, and C”, this phrase is intended to cover the selection of only the first listed option (A), or only the second listed option (B), or only the third listed option (C), or only the first and second listed options (A and B), or only the first and third listed options (A and C), or only the second and third listed options (B and C), or the selection of all three options (A, B, and C). This can be extended to as many items as are listed, as will be clear to those skilled in the art and related fields.

[0120] Moreover, as used herein, the term “signaling” refers, among other things, to instructing the corresponding decoder to do something. Encoder signals may include, for example, encoding functions on the input of a block using a progress factor, etc. In this way, in one example, the same parameter is used on both the encoder and decoder sides. Thus, for example, the encoder may transmit a specific parameter (explicit signaling) to the decoder so that the decoder can use the same specific parameter. Conversely, if the decoder already has the specific parameter as well as other parameters, then signaling can be used without transmission (implicit signaling) to simply allow the decoder to know and select the specific parameter. Bit saving is achieved in various examples by avoiding the transmission of any actual function. It should be understood that signaling can be done in a variety of ways. For example, in various examples, one or more syntax elements, tags, etc., are used to signal information to the corresponding decoder. Although the foregoing refers to the verb form of the term “signaling,” the term “signaling” may (e.g., it can also) be used as a noun here.

[0121] As will be apparent to those skilled in the art, implementations can generate various signals formatted to carry, for example, information that can be stored or transmitted. The information may include, for example, instructions for performing a method or data generated by one of the described implementations. For example, the signal may be formatted to carry a bit stream of the described example. Such a signal may be formatted as, for example, an electromagnetic wave (e.g., using the radio frequency portion of a spectrum) or a baseband signal. Formatting may include, for example, encoding the data stream and modulating a carrier wave using the encoded data stream. The information carried by the signal may be, for example, analog or digital information. The signal may be transmitted over a variety of different wired or wireless links, as is well known. The signal may be stored on or accessed from a processor-readable medium.

[0122] This document describes numerous examples. Features of the examples may be provided individually or in any combination across various claim classes and types. Further, examples may include one or more of the features, devices, or aspects described individually or in any combination across various claim classes and types. For example, the features described herein may be implemented in a bitstream or signal that includes information generated as described herein. This information may allow a decoder to decode the bitstream, encoder, bitstream, and / or decoder according to any of the described embodiments. For example, the features described herein may be implemented by creating and / or transmitting and / or receiving and / or decoding the bitstream or signal. For example, the features described herein may be implemented using methods, processes, apparatus, media storing instructions, media storing data, or signals. For example, the features described herein may be implemented by a TV, set-top box, cellular phone, tablet, or other electronic device performing decoding. The TV, set-top box, cellular phone, tablet, or other electronic device may display (e.g., using a monitor, screen, or other type of display) the obtained image (e.g., a signal reconstructed from the residual of a video bitstream). The TV, set-top box, cellular phone, tablet, or other electronic device may receive a signal including an encoded image and perform decoding.

[0123] These examples can be executed by a device having at least one processor. The device can be an encoder or a decoder. These examples can be executed by a computer program product stored on a non-transient computer-readable medium and including program code instructions. These examples can be executed by a computer program including program code instructions.

[0124] Low-frequency non-separable transform (LFNST) (e.g., secondary transform) and non-separable master transform (NSPT) can be performed by the video coding device described herein. LFNST can include: multiple LFNST sets (S) and candidates (C), extended to S=35 and C=3. The LFNST set (lfnstTrSetIdx) for a given intra-frame mode (predModeIntra) can be derived according to the following formula: For predModeIntra < 2, lfnstTrSetIdx equals 2. For predModeIntra in [0,34], lfnstTrSetIdx = predModeIntra For predModeIntra in [35, 66], lfnstTrSetIdx = 68 – predModeIntra.

[0125] Three different kernels, LFNST4, LFNST8, and LFNST16, can be defined as indicating the set of LFNST kernels, which can be applied to 4×N / N×4 (N≥4), 8×N / N×8 (N≥8), and M×N (M, N≥16), respectively. The kernel dimension can be specified by the following formula: (LFNST4, LFNST8*, LFNST16*) = (16×16, 32×64, 32×96).

[0126] Forward LFNST can be applied to the upper left low-frequency region, which can be referred to as the region of interest (ROI). If LFNST is applied, the coefficients of the principal transform existing in regions other than the ROI can be cleared to zero.

[0127] Figure 5 The diagram illustrates an example of an ROI for LFNST16. LFNST 16 can comprise six 4×4 sub-blocks, which can be consecutive in scan order (Z-scan). Since the number of input samples can be 96, the transformation matrix for forward LFNST16 can be R×96. R can be chosen as 32 in the ECM. Correspondingly, 32 coefficients (two 4×4 sub-blocks) can be generated from forward LFNST16, which can be placed in coefficient scan order (e.g., as shown). Figure 5 As shown in the image).

[0128] Figure 6 The diagram illustrates an example of an ROI for LFNST8. The forward LFNST8 matrix can be R×64, and R can be chosen to be 32. The generated coefficients can be positioned in the same way as for LFNST16.

[0129] The mapping from intra-prediction modes to these sets is shown in Table 1 below. Table 1: Mapping of intra-frame prediction modes to LFNST set indices.

[0130] Figure 7 An example NSPT is illustrated, in which a single inseparable transformation replaces the two-stage transformation (DCT2-LFNST). This can (e.g., can only) be allowed for small blocks.

[0131] NSPT (e.g., all NSPTs) can include 35 sets and 3 candidates (similar to the current LFNST). The kernel of an NSPT can have at least one of the following shapes: NSPT4×4: 16×16; NSPT4×8 / NSPT8×4: 32×20; NSPT8×8: 64×32; NSPT4×16 / NSPT16×4: 64×24; or NSPT8×16 / NSPT16×8: 128×40. Therefore, NSPT4×8 / NSPT8×4, NSPT8×8, NSPT4×16 / NSPT16×4, and NSPT8×16 / NSPT16×8 can be used to zero out 12, 32, 40, and 88 coefficients, respectively.

[0132] The NSPT transform presented in this paper can replace the DCT2-LFNST stage, where a single, inseparable transform can be used. This can be (e.g., only) allowed for small blocks (e.g., because inseparable transforms for large blocks can require huge memory and computational complexity). The NSPT transform presented in this paper can improve compression efficiency by extending the use of NSPT to larger block sizes without introducing an additional NSPT kernel.

[0133] In the example, the video encoder and / or decoder can derive smaller blocks than the input blocks for some blocks larger than the block size supported by NSPT. The smaller blocks can be encoded using NSPT. NSPT transforms can be applied to the smaller blocks. Quantization and entropy encoding can be performed on the derived smaller residual blocks.

[0134] In the example, the video encoder can subsample the residual block to a lower block size supported by NSPT. The video encoder can apply NSPT designed for the reduced size of the residual block. The video encoder can then quantize and entropy-encode the residual block at a reduced resolution.

[0135] In the example, the video decoder can perform entropy decoding on the residual block. The video decoder can determine whether the decoding result satisfies the maximum NSPT scan position rule, taking into account the reduced residual block size, and can dequantize the residual block. If the determined maximum NSPT scan position condition is satisfied, inverse NSPT can be applied, and the inverse transform block can be upsampled to the original TU size. In the example, the canonical rule can map the original TB size to a reduced TB size for applying NSPT. In the example, the proposed extended NSPT scheme can be applied to block sizes of 32×4 and 4×32. In the example, a difference block can be computed between the reconstructed encoded residual block and the original residual block (e.g., replacing all transform coefficients except those of the reduced size with zero for quantization and entropy coding). The difference block can be (e.g., can then) compressed. In the example, the difference block can be encoded by a transform skipping the encoding process.

[0136] Figure 8 An example of a residual coding process is illustrated. The residual coding process can involve transform, quantization, and transform coefficient entropy coding. The input to the process can be the residual block to be encoded, along with its associated `mts_idx` and `lfnst_idx`. `mts_idx` can be the index of the primary transform used. If NSPT is not allowed for the block under consideration, then `lfnst_idx` can be the index of the secondary transform used. If NSPT is allowed, then `lfnst_idx` can indicate the index of the NSPT transform used for the block under consideration.

[0137] If NSPT is allowed and lfnst_idx is not 0, NSPT can be applied, resulting in a transformed block. Otherwise, if NSPT is not allowed, the main transformation can be applied based on the mts_idx value. If the block size is within the range supported by NSPT and Figure 7 The set of block sizes shown allows NSPT to be enabled for a given block. If lfnst_idx is not 0, then LFNST can be applied by using the LFNST transform kernel derived from the lfnst_idx value (and possibly, the intra-frame mode for intra-frame prediction of the considered CU). The transformed block can (e.g., can then) undergo quantization and entropy coding. The mts_idx and lfnst_idx syntax elements, respectively indicating the primary and secondary transforms used for the considered residual block, can be encoded.

[0138] Figure 9An example of the residual decoding process is illustrated. During decoding, the transform coefficients can be entropy-decoded. The video decoder can (e.g., it can then) check whether the decoded transform coefficients satisfy or violate a canonical condition to enable LFNST or NSPT for the block under consideration. This canonical condition may include checking the position of the last non-zero coefficient in the block. The position of the coefficient in the scan order can be compared with a scan order position threshold. If the scan order is high, then LFNST / NSPT can be canonically disallowed for the block under consideration. The scan order position threshold may depend on the block size.

[0139] If the position of the last significant coefficient violates the position threshold rule for LFNST / NSPT, then lfnst_idx can be inferred as 0. Otherwise, lfnst_idx can be decoded from the bitstream. mts_idx can be (e.g., then) decoded. If lfnst_idx is nonzero and NSPT is allowed with respect to block size, then inverse NSPT can be applied to the dequantized coefficients. If lfnst_idx is nonzero and NSPT is not allowed, then inverse LFNST can be applied. The inverse main transform can be (e.g., then) applied.

[0140] Figure 10 The diagram illustrates an example block residual coding process using the extended NSPT procedure. The video coding device can identify residual blocks. Residual blocks can be associated with primary and secondary transform indices. NSPT is applicable if lfnst_idx is nonzero and the block size allows it. Otherwise, the video coding device can determine whether lfnst_idx is nonzero and whether extended NSPT is allowed. Larger NSPTs can be allowed for certain block sizes larger than the NSPT block size (e.g., such as...). Figure 7 (As shown in the example). In the example, the NSPT can be expanded for block sizes of 32×4 and 4×32.

[0141] If expanding the NSPT is not allowed, then typically the primary and secondary transforms can be applied to the current block. If expanding the NSPT is allowed and the secondary transform is non-zero, then the video coding device can derive a reduced residual block size from the input residual block size. This derivation can map the initial block size to the reduced block size according to one or more predefined rules. In the example, the predefined rules(s) ...

[0142] If the NSPT is increased and the secondary transform is non-zero, the video coding device can downsample the residual block to a reduced residual block size. This downsampling can employ interpolation filters (e.g., filters used for reference picture resampling tools (e.g., RPR) and / or motion-compensated interpolation filters). Other filters (e.g., bilinear filters) can also be used for this downsampling operation.

[0143] If expanding the NSPT is permitted and the secondary transformation is non-zero, the NSPT can be applied to the reduced residual block. This may result in a reduced-size transformed block. From this reduced-size transformed block, a set of transformation coefficients can be obtained and arranged in the resulting block (e.g., as shown in the original block size). Figure 11 (As shown in the diagram). The upper left region of the reduced residual block may include coefficients transformed by NSPT, and the remainder of the reduced residual block may be filled with zero coefficients.

[0144] The video coding device can perform quantization, transform, and entropy coding of transform blocks derived from the proposed extended NSPT process. It can encode both the primary transform index and the secondary transform index.

[0145] Figure 12 The illustration shows an example block residual decoding process using the extended NSPT procedure. The video decoding device can perform entropy decoding on the quantized coefficients of the residual block. The video decoding device can check whether the specification rules for allowing LFNST / NSPT are violated. A scan order threshold can be used to compare the position of the last significant coefficient in the residual block with the threshold to determine whether the input block size allows for a large NSPT. For blocks where a large NSPT is allowed, a reduced block size for which NSPT has been applied (e.g., as shown in the image) can be calculated. Figure 10 (As shown in the diagram). For blocks where large NSPTs are allowed, the scan position threshold can be a scan position threshold associated with the residual block size equal to the reduced block size under consideration. If the scan position of the last significant coefficient in the block is above the considered threshold, then large NSPTs can be disallowed for the block and lfnst_idx can be inferred as 0. If the scan position of the last significant coefficient in the block is below the considered threshold, then large NSPTs can be allowed and the lfnst_idx syntax elements and mts_idx syntax elements can be decoded.

[0146] If lfnst_idx is nonzero and NSPT is allowed for the residual block, then inverse NSPT can be applied. If NSPT is not allowed for the residual block, the video decoding device can determine whether lfnst_idx is nonzero and whether extended NSPT is allowed for the residual block.

[0147] Based on the fact that the secondary transform index is non-zero and that expanding the NSPT is allowed for residual blocks, a reduced NSPT block size can be derived from the input block size (e.g., as shown below). Figure 10 (As shown in the diagram). The inverse NSPT can be applied to the upper left region of the reduced NSPT block. The sub-block transformed by the inverse NSPT can be upsampled to the initial residual block size. In examples where lfnst_idx is 0 or large NSPT is not allowed, the usual inverse LFNST and inverse master transform can be applied.

[0148] The examples in this paper can provide improved compression efficiency by using NSPT on an expanded set of block sizes. The examples in this paper can (e.g., also) provide a reduction in the number of operations involved compared to an introduced NSPT transform kernel adapted to the same addressable block size.

[0149] In the example, the extended NSPT can be applied to block sizes of 32×4 and 4×32 (e.g., only). In the example, the residual signal (e.g., further residual signal) can be encoded (e.g., to improve the residual block) complementary to the downsampled residual-coded NSPT. This can take the form of a difference block between the original residual block and the decoded residual block in the case of inverse NSPT and upsampling. In the example, this difference block can be encoded by transforming and skipping the residual coding mode.

[0150] Although features and elements have been described above in specific combinations, those skilled in the art will appreciate that each feature or element may be used individually or in any combination with other features and elements. Furthermore, the methods described herein can be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via wired or wireless connections) 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 internal hard disks and removable disks), magnetic-optical media, and optical media (such as CD-ROMs and digital multifunction discs (DVDs)). The processor associated with the software can 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, comprising: The processor is configured as follows: Decode the quantized coefficients of the residual block; The scan position of the last significant coefficient in the residual block is compared with the threshold. Based on the fact that the last significant coefficient scan position in the residual block is lower than the threshold, the auxiliary transform index and the main transform index are decoded; The auxiliary transform index is non-zero, and the expansion of the non-separable main transform (NSPT) is permitted for the residual block: The reduced NSPT block size is derived from the residual block; Apply the inverse NSPT to the reduced NSPT block size to obtain NSPT-transformed sub-blocks; and The sub-blocks transformed by NSPT are upsampled to the size of the residual block.

2. A video decoding method, the method comprising: Decode the quantized coefficients of the residual block; The scan position of the last significant coefficient in the residual block is compared with the threshold. Based on the fact that the last significant coefficient scan position in the residual block is lower than the threshold, the auxiliary transform index and the main transform index are decoded; The auxiliary transform index is non-zero, and the expansion of the non-separable main transform (NSPT) is permitted for the residual block: The reduced NSPT block size is derived from the residual block; Apply the inverse NSPT to the reduced NSPT block size to obtain NSPT-transformed sub-blocks; and The sub-blocks transformed by NSPT are converted to the size of the residual block.

3. The video decoding device of claim 1 or the video decoding method of claim 2, wherein the threshold is a scan position threshold associated with comparing the residual block size with the reduced block size.

4. The video decoding apparatus of any one of claims 1 and 3, or the video decoding method of any one of claims 2 to 3, wherein the processor of any one of claims 1 and 3 is further configured to perform the following, or the method of any one of claims 2 to 3 further includes the following: The reduced NSPT block size is further derived from the residual block based on NSPT, which is not allowed for the residual block.

5. The video decoding apparatus as claimed in any one of claims 1 and 3 to 4, or the video decoding method as claimed in any one of claims 2 to 4, wherein applying the inverse NSPT to the reduced NSPT block size means applying the inverse NSPT to the upper left region of the reduced NSPT block size.

6. The video decoding apparatus of any one of claims 1 and 3 to 5, or the video decoding method of any one of claims 2 to 5, wherein the processor of any one of claims 1 and 3 to 5 is further configured to perform the following, or the method of any one of claims 2 to 5 further includes the following: The main and auxiliary transformations are applied based on the fact that the auxiliary transform index is zero or the non-separable main transform (NSPT) is not allowed for the residual block.

7. The video decoding apparatus of any one of claims 1 and 3 to 6 or the video decoding method of any one of claims 2 to 6, wherein extending the NSPT for the residual block is permitted to include extending the NSPT by applying the NSPT to a block size of 32×4 or 4×32.

8. A video encoding device, comprising: The processor is configured as follows: Identify residual blocks, wherein the residual blocks are associated with the primary transform index and the secondary transform index; Determine whether the secondary transform index is non-zero and whether expanding the non-separable primary transform (NSPT) is allowed; This is permitted based on the auxiliary transformation being nonzero and the expansion of NSPT for the residual block: The reduced residual block size is derived from the residual block size associated with the residual block; The residual block is downsampled to the reduced residual block size; Apply NSPT to the reduced residual block size to obtain the transformed reduced block; as well as Perform quantization, transform, and entropy coding on the transformed, smaller blocks; and The primary transform index and the secondary transform index are encoded.

9. A video encoding method, the method comprising: Identify residual blocks, wherein the residual blocks are associated with the primary transform index and the secondary transform index; Determine whether the secondary transform index is non-zero and whether expanding the non-separable primary transform (NSPT) is allowed; This is permitted based on the auxiliary transformation being nonzero and the expansion of NSPT for the residual block: The reduced residual block size is derived from the residual block size associated with the residual block; The residual block is downsampled to the reduced residual block size; Apply NSPT to the reduced residual block size to obtain the transformed reduced block; as well as Perform quantization, transform, and entropy coding on the transformed, smaller blocks; and The primary transform index and the secondary transform index are encoded.

10. The video encoding apparatus of claim 8 or the video encoding method of claim 9, wherein the reduced residual block size is associated with the largest region of supported NSPTs included in the residual region.

11. The video encoding apparatus of any one of claims 8 and 10 or the video encoding method of any one of claims 9 to 10, wherein the downsampling of the residual block uses an interpolation filter.

12. The video encoding apparatus of any one of claims 8 and 10 to 11 or the video encoding method of any one of claims 9 to 11, wherein the upper left region of the reduced residual block size includes coefficients transformed by NSPT, and the remaining portion of the reduced residual block size includes zero coefficients.

13. The video encoding apparatus of any one of claims 8 and 10 to 12, or the video encoding method of any one of claims 9 to 12, wherein the processor of any one of claims 8 and 10 to 12 is further configured to perform the following, or the method of any one of claims 9 to 12 further includes the following: The main and auxiliary transformations are applied based on the fact that the auxiliary transform index is zero or the non-separable main transform (NSPT) is not allowed for the residual block.

14. The video encoding apparatus of any one of claims 8 and 10 to 13 or the video encoding method of any one of claims 9 to 13, wherein extending the NSPT for the residual block is permitted to include extending the NSPT by applying the NSPT to a block size of 32×4 or 4×32.

15. A computer program product stored on a non-transient computer-readable medium and comprising program code instructions for implementing the steps of the method according to at least one of claims 2 to 7 and 9 to 14 when executed by at least one processor.

16. A computer program comprising program code instructions for implementing, when executed by a processor, the program code instructions for performing the steps of the method according to at least one of claims 2 to 7 and 9 to 14.

17. Video data comprising information representing an encoded output generated by any one of the methods according to any one of claims 9 to 14.

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