combined qp-specific pre-trained filter

Abstract

During adaptive loop filtering (ALF), multiple quantization parameter (QP)-specific pre-trained filters can be combined. A video coding device, which can be, for example, an encoder device or a decoder device, can include at least one processor configured to determine a plurality of sets of pre-trained ALF QP-specific filters. The video coding device can determine a QP value and can select a plurality of sets of ALF QP-specific filters from the plurality of sets of pre-trained adaptive loop filter (ALF) QP-specific filters based on the QP value. The video coding device can apply each of the plurality of sets of ALF QP-specific filters to video samples associated with video data to generate respective output samples. The video coding device can combine the respective output samples.

Description

[0001] Cross-references to related applications This application claims the benefit of European Patent Application No. 24305050.7, filed on January 9, 2024, the contents of which are hereby incorporated by reference in their entirety. Background Technology

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

[0003] Systems, methods, and means for combining multiple quantization parameter (QP) specific pre-trained filters during adaptive loop filtering (ALF) are disclosed.

[0004] A video encoding device, which may be referred to as an encoder, may include at least one processor and may be configured to determine quantization parameter (QP) values ​​and select multiple adaptive loop filter (ALF) QP-specific filter banks based on the QP values. The video encoding device may be configured to apply each of the multiple ALF QP-specific filter banks to video samples associated with video data to generate corresponding output samples and to combine the corresponding output samples.

[0005] Multiple ALF QP-specific filter banks may include two ALF QP-specific filter banks. The video coding apparatus may be further configured to determine a corresponding weighting factor for each codec tree unit (CTU) included in the video data. The video coding apparatus configured to combine corresponding output samples may be further configured to apply the corresponding weighting factor to a corresponding one of the corresponding output samples. The video coding apparatus may be further configured to send the corresponding weighting factor for each CTU included in the video data.

[0006] The video coding device can be configured to derive a first weighting factor and a second weighting factor based on the QP value. The video coding device configured to combine corresponding output samples can be configured to apply the first weighting factor to the first of the corresponding output samples and apply the second weighting factor to the second of the corresponding output samples.

[0007] A video encoding device can be configured to determine an adaptive filter having at least one added tap. A video encoding device configured to combine corresponding output samples can be configured to apply an adaptive filter having at least one added tap. The video encoding device can be further configured to send an indication of an adaptive filter having at least one added tap.

[0008] A video decoding device, which may be referred to as a decoder, may include at least one processor and may be configured to determine quantization parameter (QP) values ​​and select multiple adaptive loop filter (ALF) QP-specific filter banks based on the QP values. The video decoding device may be configured to apply each of the multiple ALF QP-specific filter banks to video samples associated with video data to generate corresponding output samples and to combine the corresponding output samples.

[0009] Multiple ALF QP-specific filter banks may include two ALF QP-specific filter banks. The video decoding device may further be configured to determine a corresponding weighting factor for each codec tree unit (CTU) included in the video data. The video decoding device, configured to combine corresponding output samples, may further be configured to apply the corresponding weighting factor to one of the corresponding output samples. The corresponding weighting factor can be received in the video data.

[0010] A video decoding device can be configured to determine an adaptive filter with at least one added tap. The video decoding device can receive an indication of an adaptive filter with at least one added tap. A video decoding device configured to combine corresponding output samples can be configured to apply an adaptive filter with at least one added tap.

[0011] A video codec device, which may be, for example, an encoder device or a decoder device, may include at least one processor configured to determine a plurality of pre-trained ALF QP-specific filter banks. The video codec device can determine QP values ​​and can select a plurality of ALF QP-specific filter banks based on the QP values. The video codec device can apply each of the plurality of ALF QP-specific filter banks to video samples associated with video data to generate corresponding output samples. The video encoding device can combine the corresponding output samples.

[0012] The video codec can determine that multiple ALF QP-specific filter banks include two ALF QP-specific filter banks. The video codec can determine a corresponding weighting factor for each CTU included in the video data. The video codec can transmit the video data, and for each CTU included in the video data, it can transmit the corresponding weighting factor. The video codec can be further configured to transmit an indication in the video data that multiple ALF QP-specific filter banks have been applied. Attached Figure Description

[0013] Figure 1A This is a system diagram illustrating an example communication system in which one or more of the disclosed embodiments may be implemented.

[0014] Figure 1B To illustrate, according to an embodiment, it is possible to Figure 1A The diagram shows a system diagram of an example wireless transmit / receive unit (WTRU) used in a communication system.

[0015] Figure 1C To illustrate, according to an embodiment, it is possible to Figure 1A The diagram illustrates a system diagram of an example radio access network (RAN) and an example core network (CN) used within a communication system.

[0016] Figure 1D To illustrate, according to an embodiment, it is possible to Figure 1A The diagram shows another example RAN and another example CN used in the communication system.

[0017] Figure 2 The illustration shows a sample video encoder.

[0018] Figure 3 The illustration shows an example video decoder.

[0019] Figure 4 The illustration shows an example of a system that can implement various aspects and examples.

[0020] Figure 5 The diagram illustrates the workflow of an example loop filter.

[0021] Figure 6 An example implementation of an ALF filter is illustrated.

[0022] Figure 7 The workflow of the example filter is described.

[0023] Figure 8 The illustration shows the example minimum and maximum filter bank indices.

[0024] Figure 9 The illustration shows the shape of a filter that sends an ALF signal to indicate the brightness.

[0025] Figure 10 The illustration shows an example process for combining QP-qualified filters.

[0026] Figure 11 The diagram illustrates the adaptive filter shape for the signal notification of the Example 37 tap.

[0027] Figure 12 An exemplary 40-tap adaptive filter shape for signaling notification is illustrated. Detailed Implementation

[0028] A more detailed understanding can be obtained from the following description, which is given in illustrative form in conjunction with the accompanying drawings.

[0029] Figure 1A The 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 Spread Spectrum OFDM (ZT UW DTS-s OFDM), Unique Word OFDM (UW-OFDM), Resource Block Filtered OFDM, Filter Bank Multicarrier (FBMC), etc.

[0030] 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. However, it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. For example, any of the WTRUs 102a, 102b, 102c, and 102d, 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 the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0031] 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. For example, base stations 114a and 114b may be a basic transceiver station (BTS), Node-B, eNode B, home NodeB, home eNode B, gNB, NR NodeB, site controller, access point (AP), wireless router, etc. Although each of base stations 114a and 114b is depicted as a single element, it will be appreciated that base stations 114a and 114b may include any number of interconnected base stations and / or network elements.

[0032] 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 in permitted spectrum, unpermitted spectrum, or a combination of permitted and unpermitted spectrum. A cell may provide coverage for a specific geographic area, 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 embodiments, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in a desired spatial direction.

[0033] Base stations 114a and 114b can communicate with one or more of WTRUs 102a, 102b, 102c, and 102d via air interface 116. The air interface can be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). Air interface 116 can be established using any suitable radio access technology (RAT).

[0034] 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, 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).

[0035] In the embodiment, base station 114a and WTRUs 102a, 102b, 102c can implement radio technologies such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which can establish air interface 116 using Long Term Evolution (LTE) and / or LTE Advanced (LTE-A) and / or LTE Advanced Pro (LTE-A Pro).

[0036] In the embodiment, base station 114a and WTRUs 102a, 102b, 102c can implement radio technologies such as NR radio access, which can establish air interface 116 using new radio (NR).

[0037] In the embodiments, 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, for example, use the dual connectivity (DC) principle to implement both LTE and NR radio access together. 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).

[0038] In other embodiments, base station 114a and WTRUs 102a, 102b, 102c can implement radio technologies such as IEEE 802.11 (i.e., Wi-Fi), IEEE 802.16 (i.e., Global Microwave Access Interoperability (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 GSM Evolution Data Rate (EDGE), GSM EDGE (GERAN), etc.

[0039] 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 business premises, residence, 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 another 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 cellular-based RATs (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 can have a direct connection to Internet 110. Therefore, it is not required that base station 114b access Internet 110 via CN 106 / 115.

[0040] 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 WTRU 102a, 102b, 102c, and 102d. Data can have varying Quality of Service (QoS) requirements, such as different throughput requirements, latency requirements, fault 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 implement advanced security features such as user authentication. Although not explicitly stated... Figure 1AAs shown, but will be understood, RAN 104 / 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 connecting to RAN 104 / 113, which may be using NR radio technology, CN 106 / 115 can also communicate with another RAN (not shown) using GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0041] CN 106 / 115 can also serve 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 that may employ the same RAT as or a different RAT than RAN 104 / 113.

[0042] 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 base station 114a, which may employ cellular-based radio technology, and with base station 114b, which may employ IEEE 802 radio technology.

[0043] Figure 1B The following diagram illustrates the system of example WTRU 102. Figure 1B As shown, among other things, 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 peripheral devices 138. It will be appreciated that WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with the embodiments.

[0044] 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. Processor 118 may perform signal encoding / decoding, data processing, power control, input / output processing, and / or any other functions that enable WTRU 102 to operate in a wireless environment. Processor 118 may be coupled to transceiver 120, and transceiver 120 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 into an electronic package or chip.

[0045] 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 another 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 signals 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.

[0046] Although the transmitting / receiving element 122 is in Figure 1B While depicted as a single element, WTRU 102 may include any number of transmit / receive elements 122. More specifically, WTRU 102 may employ MIMO technology. Thus, in one embodiment, WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals via air interface 116.

[0047] Transceiver 120 can be configured to modulate signals to be transmitted by transmitting / receiving element 122 and demodulate signals to be received by transmitting / receiving element 122. As noted above, WTRU 102 can have multi-mode capability. Therefore, transceiver 120 can include multiple transceivers for enabling WTRU 102 to communicate via various RATs such as NR and IEEE 802.11, for example.

[0048] The processor 118 of WTRU 102 can be coupled to a speaker / microphone 124, a keypad 126, and / or a 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 these devices. The processor 118 can also output user data to the speaker / microphone 124, keypad 126, and / or display / touchpad 128. Furthermore, the processor 118 can access information from any type of suitable memory and store the data in memory such as non-removable memory 130 and / or removable memory 132. Non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. Removable memory 132 may include a subscriber identity module (SIM) card, memory stick, secure digital storage (SD) card, etc. In other embodiments, the processor 118 can access information from memory that is not physically located on WTRU 102 (such as on a server or home computer (not shown)) and store the data in that memory.

[0049] The processor 118 can receive power from the power supply 134 and can be configured to distribute and / or control power 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 cell units, fuel cell units, etc.

[0050] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or 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 the air interface 116, and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be understood that the WTRU 102 may obtain location information using any suitable location determination method, while remaining consistent with the embodiments.

[0051] The processor 118 may be further coupled to other peripheral devices 138, which may include one or more software and / or hardware modules providing additional features, functions, and / or wired or wireless connectivity. For example, peripheral devices 138 may include accelerometers, electronic compasses, satellite transceivers, digital cameras (for photos and / or video), 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. Peripheral devices 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.

[0052] WTRU 102 may include a full-duplex radio, for which the transmission and reception of some or all signals (e.g., associated with a specific subframe of 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 embodiments, WTRU 102 may include a half-duplex radio, for which the transmission and reception of some or all signals (e.g., associated with a specific subframe of either UL (e.g., for transmission) or downlink (e.g., for reception) may be concurrent and / or simultaneous.

[0053] Figure 1C The diagram illustrates a system diagram of RAN 104 and CN 106 according to an embodiment. As noted above, RAN 104 may employ E-UTRA radio technology to communicate with WTRUs 102a, 102b, and 102c via air interface 116. RAN 104 may also communicate with CN 106.

[0054] RAN 104 may include eNode-B 160a, 160b, 160c, but will be appreciated that RAN 104 may include any number of eNode-Bs while remaining consistent with the embodiments. Each of eNode-B 160a, 160b, 160c may include one or more transceivers for communicating with WTRU 102a, 102b, 102c via air interface 116. In one embodiment, eNode-B 160a, 160b, 160c may implement MIMO technology. Thus, for example, eNode-B 160a may use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU 102a.

[0055] 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, user scheduling in UL and / or DL, etc. Figure 1C As shown, eNode-B 160a, 160b, and 160c can communicate with each other via the X2 interface.

[0056] 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. While each of the foregoing elements is depicted as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0057] The MME 162 can connect to each of the eNode-Bs 162a, 162b, and 162c in RAN 104 via the S1 interface and can be used as a control node. For example, the MME 162 can be responsible for authenticating users of WTRUs 102a, 102b, and 102c, bearer activation / deactivation, selecting a specific serving gateway during the initial attachment of WTRUs 102a and 102c, etc. 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.

[0058] The SGW 164 can connect to each eNode B 160a, 160b, or 160c in RAN 104 via the S1 interface. The SGW 164 can typically route user data packets to or forward user data packets from WTRUs 102a, 102b, or 102c. The SGW 164 can also 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, or 102c, and managing and storing the context of WTRUs 102a, 102b, or 102c.

[0059] The SGW 164 can connect to the PGW 166, which can provide WTRU 102a, 102b, and 102c with access to packet-switched networks such as Internet 110, facilitating communication between WTRU 102a, 102b, 102c and IP-enabled devices.

[0060] CN 106 can facilitate communication with other networks. For example, CN 106 can provide WTRU 102a, 102b, and 102c with access to circuit-switched networks such as PSTN 108 to facilitate communication between WTRU 102a, 102b, and 102c and traditional landline communication equipment. For example, CN 106 may include, or be able to communicate with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) serving as an interface between CN 106 and PSTN 108. Furthermore, CN 106 can provide WTRU 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.

[0061] Despite WTRU in Figures 1A-1D While described as a wireless terminal, it is conceivable that in some representative embodiments, such a terminal may (e.g., temporarily or permanently) use a wired communication interface with a communication network.

[0062] In a representative embodiment, the other network 112 may be a WLAN.

[0063] A WLAN in Infrastructure Basic Services Set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that introduces and / or leads traffic into and / or out of the BSS. Traffic originating outside the BSS and destined for a STA can be delivered to the AP. Traffic originating from a STA and destined for a destination outside the BSS can be sent to the AP for delivery to its respective destination. Traffic between STAs within the BSS can be sent, for example, through the AP, 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 the source STA and the destination STA (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 the IBSS or using the IBSS (e.g., all STAs) can communicate directly with each other. The IBSS communication mode may sometimes be referred to as the "ad-hoc" communication mode in this document.

[0064] When operating in 802.11ac infrastructure mode or a similar mode, the AP can transmit beacons on a fixed channel, such as the primary channel. The primary channel can be of fixed width (e.g., a 20 MHz bandwidth) or dynamically set via signaling. The primary channel can be the operating channel of the BSS and can be used by the STA to establish a connection with the AP. In some representative embodiments, such as in an 802.11 system, Carrier Sense Multiple Access (CSMA / CA) with collision avoidance can be implemented. For CSMA / CA, each STA (e.g., every STA), including the AP, can sense the primary channel. If a particular STA senses / detects and / or determines that the primary channel is busy, that particular STA can exit. A single STA (e.g., only one station) can transmit at any given time within a given BSS.

[0065] High-throughput (HT) STAs can communicate using a 40 MHz wide channel, for example, by combining a primary 20 MHz channel with adjacent or non-adjacent 20 MHz channels to form a 40 MHz wide channel.

[0066] Very High Throughput (VHT) STAs can support channels with widths of 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz. A 40 MHz and / or 80 MHz channel can be formed by combining consecutive 20 MHz channels. A 160 MHz channel can be formed by combining eight consecutive 20 MHz channels, or by combining two non-consecutive 80 MHz channels (this can be referred to as an 80+80 configuration). For the 80+80 configuration, after channel coding, data is passed through a segmented parser that splits the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time-domain processing can be performed on each stream separately. The streams can be mapped onto the two 80 MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the operation of the 80+80 configuration can be reversed, and the combined data can be sent to the Media Access Control (MAC).

[0067] 802.11af and 802.11ah support operating modes below 1 GHz. The channel operating bandwidth and carrier in 802.11af and 802.11ah are reduced compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV whitespace (TVWS) spectrum, while 802.11ah uses non-TVWS spectrum to support 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths. According to a representative embodiment, 802.11ah can support instrument-type control / machine-type communication, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support (e.g., only support) certain and / or limited bandwidths. MTC devices may include batteries with a battery life exceeding a threshold (e.g., to maintain a very long battery life).

[0068] WLAN systems that can support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include channels that can be designated as 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 STAs supporting the minimum bandwidth operating mode from all STAs operating in the BSS. In the example of 802.11ah, for STAs supporting (e.g., only supporting) the 1 MHz mode (e.g., MTC type devices), the primary channel can still be 1 MHz wide even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to STAs (which only support the 1 MHz operating mode) transmitting to the AP, the entire available band may be considered busy even if most of the band remains idle and potentially available.

[0069] In the United States, the available frequency band for 802.11ah is 902 MHz to 928 MHz. In South Korea, the available frequency band is from 917.5 MHz to 923.5 MHz. In Japan, the available frequency band is from 916.5 MHz to 927.5 MHz. Depending on the country code, the total bandwidth available for 802.11ah ranges from 6 MHz to 26 MHz.

[0070] Figure 1D The diagram illustrates a system diagram of RAN 113 and CN 115 according to an embodiment. As noted above, RAN 113 can use NR radio technology to communicate with WTRUs 102a, 102b, and 102c via air interface 116. RAN 113 can also communicate with CN 115.

[0071] RAN 113 may include gNBs 180a, 180b, and 180c; however, it will be understood that RAN 113 may include any number of gNBs while remaining consistent with the embodiments. Each of gNBs 180a, 180b, and 180c may 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. Thus, for example, gNB 180a may use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU 102a. In an embodiment, gNBs 180a, 180b, and 180c may implement carrier aggregation technology. For example, gNB 180a can transmit multiple component carriers to WTRU 102a (not shown). A subset of these component carriers may be located on unlicensed spectrum, while the remaining component carriers may be located on licensed spectrum. In embodiments, gNBs 180a, 180b, and 180c can implement Coordinated Multipoint (CoMP) technology. For example, WTRU 102a can receive coordinated transmissions from gNBs 180a and 180b (and / or gNB 180c).

[0072] WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using transmissions associated with extended digital numerology. For example, OFDM symbol spacing and / or OFDM subcarrier spacing can vary for 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 or transmission time intervals (TTIs) of various or extended lengths (e.g., containing different numbers of OFDM symbols and / or absolute times of varying durations).

[0073] 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 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 / connect with gNBs 180a, 180b, and 180c, and also with another RAN such as eNode-Bs 160a, 160b, and 160c. For example, WTRUs 102a, 102b, and 102c can implement DC principles to communicate essentially 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-Bs 160a, 160b, and 160c can act as mobility anchors for WTRUs 102a, 102b, and 102c, and gNBs 180a, 180b, and 180c can provide additional coverage and / or throughput to serve WTRUs 102a, 102b, and 102c.

[0074] 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, and 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.

[0075] 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. While 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.

[0076] AMF 182a and 182b can connect to one or more of gNBs 180a, 180b, and 180c in RAN 113 via the N2 interface and can be used 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 SMF 183a and 183b, managing registration areas, terminating NAS signaling, mobility management, etc. AMF 182a and 182b can use network slicing to customize CN support for WTRU 102a, 102b, and 102c based on the service types being utilized by WTRU 102a, 102b, and 102c. For example, different network slices can be established for different use cases, such as services relying on Ultra Reliable Low Latency (URLLC) access, services relying on Enhanced Massive Mobile Broadband (eMBB) access, 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.

[0077] 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 the routing of traffic 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, or Ethernet-based.

[0078] UPF 184a and 184b can connect to one or more of gNB 180a, 180b, and 180c in RAN 113 via the N3 interface. The N3 interface can provide WTRU 102a, 102b, and 102c with access to packet-switched networks such as Internet 110, facilitating communication between WTRU 102a, 102b, and 102c and IP-enabled devices. UPF 184 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.

[0079] CN 115 can facilitate communication with other networks. For example, CN 115 may include, or be able to communicate with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) serving as an interface between CN 115 and PSTN 108. Furthermore, 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 may be connected 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.

[0080] Given Figures 1A-1D as well as Figures 1A-1D The corresponding descriptions herein indicate that one or more of the functions described herein in relation to one or more of the following can be implemented by one or more emulation devices (not shown): WTRU 102a-102d, base station 114a-114b, eNode-b 160a-160c, MME 162, SGW 164, PGW 166, gNB 180a-180c, AMF 182a-182b, UPF 184a-184b, SMF 183a-183b, DN 185a-185b, and / or any other device(s) described herein. An emulation device can be one or more devices configured to emulate one or more of the functions described herein. For example, an emulation device can be used to test other devices and / or simulate network and / or WTRU functions.

[0081] Simulation devices can be designed to perform one or more tests on other devices in laboratory and / or carrier network environments. For example, one or more simulation devices can perform one or more 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. One or more simulation devices can perform one or more functions while being temporarily implemented / deployed as part of a wired or wireless communication network. Simulation devices can be directly coupled to another device for testing purposes and / or can be used for testing via over-the-air wireless communication.

[0082] One or more simulation devices can perform one or more functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, simulation devices can be used in test scenarios within test laboratories and / or undeployed (e.g., testing) wired and / or wireless communication networks to perform testing of one or more components. One or more simulation devices can be test rigs. Simulation devices can transmit and / or receive data using direct RF coupling and / or wireless communication via RF circuitry (e.g., which may include one or more antennas).

[0083] This application describes a wide variety of aspects, including tools, features, examples, models, methods, etc. Many of these aspects are described in a targeted manner and, at least to show individual characteristics, are generally described in a way that may sound restrictive. However, this is for clarity and does not limit the application or scope of those aspects. In fact, all the different aspects can be combined and interchanged to provide other aspects. Furthermore, these aspects can also be combined and interchanged with aspects described in earlier applications.

[0084] The aspects described and envisioned in this application can be implemented in many different forms. Figures 5-12 Some examples can be provided, but other examples are also envisioned. Figures 5-12 The discussion does not limit the breadth of implementations. At least one of these aspects generally relates to video encoding and decoding, and at least one other aspect generally relates to the transmission of the generated or encoded bitstream. These and other aspects can be implemented as methods, apparatus, computer-readable storage media having instructions thereon 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.

[0085] In this application, the terms “reconstruction” and “decoding” are used interchangeably, the terms “pixel” and “sample” are used interchangeably, and the terms “image”, “picture” and “frame” are used interchangeably.

[0086] This document describes various methods, each of which includes one or more steps or actions to achieve the described method. Unless a specific order of steps or actions is required for the method to operate correctly, the order and / or use of specific steps and / or actions can be modified or combined. Furthermore, terms such as "first," "second," etc., can be used in various examples to modify elements, components, steps, operations, etc., such as "first decoding" and "second decoding," for example. Unless specifically required, the use of such terms does not imply a reordering of the modified operations. Therefore, in this example, the first decoding does not need to be performed before the second decoding and can occur, for example, before, during, or within a time period overlapping with the second decoding.

[0087] The various methods and other aspects described in this application can be used to modify modules (e.g., decoding modules) of the video encoder 200 and video decoder 300, such as... Figure 2 and Figure 3 As shown. Furthermore, the subject matter disclosed herein can be applied to, for example, any type, format, or version of video codecs, whether described in pre-existing or future-developed standards or recommendations, and any extensions to such standards and recommendations. Unless otherwise indicated or technically excluded, the aspects described in this application may be used alone or in combination.

[0088] Various numerical values, such as filter values ​​and limiting parameters, are used in the examples described in this application. These and other specific values ​​are used for illustrative purposes only, and the aspects described are not limited to these specific values.

[0089] Figure 2 A diagram illustrating an example video encoder is provided. Variations of the example encoder 200 are envisioned, but for clarity, encoder 200 is described below without depicting all anticipated variations.

[0090] Before being encoded, the video sequence can undergo pre-coding (201), for example, by applying color transformations to the input color image (e.g., from RGB 4:4:4 to YCbCr 4:2:0), or by remapping the input image components to obtain a more resilient signal distribution to compression (e.g., using histogram equalization of one of the color components). Metadata can be associated with the pre-processing and attached to the bitstream.

[0091] 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, for example, codec units (CUs). Each unit is encoded using, for example, an intra-frame or inter-frame mode. When a unit is encoded in intra-frame mode, it performs intra-frame prediction (260). In 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 to encode the unit and indicates the intra-frame / inter-frame decision by, for example, a prediction mode flag. For example, the prediction residual is calculated by subtracting (210) the predicted block from the original image block.

[0092] Then, the predicted residual is transformed (225) and quantized (230). The quantized transform coefficients, along with the motion vector and other syntax elements, are entropy encoded / decoded (245) to output a bitstream. The encoder can skip the transform and apply quantization directly to the untransformed residual signal. The encoder can bypass both the transform and quantization, i.e., the residual is directly encoded / decoded without applying either the transform or quantization process.

[0093] The encoder decodes the encoded block to provide a reference for further prediction. The quantized transform coefficients are dequantized (240) and inverse transformed (250) to decode the prediction residual. The decoded prediction residual and the predicted block are combined (255) to reconstruct the image block. An in-loop filter (265) is applied to the reconstructed image to perform, for example, deblocking / SAO (Sample Adaptive Offset) / ALF (Adaptive Loop Filter) filtering to reduce coding artifacts. The filtered image is stored in a reference image buffer (280).

[0094] Figure 3 This diagram illustrates an example of a video decoder. In the example decoder 300, as described below, the bitstream is decoded by decoder elements. The video decoder 300 is typically implemented as follows... Figure 2 The encoder 200 is the inverse of the decoder traversal described in the diagram. The encoder 200 typically also performs video decoding as part of the encoding of the video data.

[0095] Specifically, the input to the decoder includes a video bitstream, which can be generated by the video encoder 200. The bitstream is first entropy decoded (330) to obtain transform coefficients, motion vectors, and other encoding / decoding information. Picture partitioning information indicates how to partition the picture. Therefore, the decoder can partition the picture according to the decoded picture partitioning information (335). The transform coefficients are dequantized (340) and inverse transformed (350) to decode the prediction residual. The decoded prediction residual and the predicted block are combined (355) to reconstruct the image block. The predicted block can be obtained from intra-frame prediction (360) or motion-compensated prediction (i.e., inter-frame prediction) (375) (370). An in-loop filter (365) is applied to the reconstructed image. The filtered image is stored in a reference picture buffer (380). Note that for a given picture, the contents of the reference picture buffer 380 on the decoder 300 side are the same as the contents of the reference picture buffer 280 on the encoder 200 side for the same picture.

[0096] The decoded image can also undergo post-decoding processing (385), such as inverse color transformation (e.g., from YCbCr 4:2:0 to RGB 4:4:4) or inverse remapping of the remapping process performed in the pre-encoding process (201). Post-decoding processing can use metadata derived in the pre-encoding process and signaled in the bitstream. In the example, the decoded image (e.g., after applying the in-loop filter (365) and / or after post-decoding processing (385) if post-decoding processing is used) can be sent to a display device for rendering to the user.

[0097] Figure 4 The diagram illustrates examples of systems in which the various aspects and examples described herein may be implemented. System 400 may be embodied as a device including the various components described below and configured to implement one or more aspects described in this document. Examples of such devices include, but are not limited to, various electronic devices such as personal computers, laptops, smartphones, tablets, 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 aspects described in this document.

[0098] System 400 includes at least one processor 410 configured to execute instructions loaded thereon to implement various aspects, such as those described in this document. Processor 410 may include embedded memory, input / output interfaces, and various other circuitry 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. As a non-limiting example, storage device 440 may include internal storage devices, attached storage devices (including removable and non-removable storage devices), and / or network-accessible storage devices.

[0099] 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 can 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. Additionally, as those skilled in the art will appreciate, 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.

[0100] Program code to be loaded onto processor 410 or encoder / decoder 430 to implement the various aspects described in this document may be stored in storage device 440 and subsequently loaded onto memory 420 for execution by processor 410. 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 various items during the execution of the processes described in this document. Such stored items may include, but are not limited to, input video, decoded video or portions of decoded video, bitstreams, matrices, variables, and intermediate or final results from the processing of equations, formulas, operations, and operational logic.

[0101] 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., the processing device could be processor 410 or encoder / decoder module 430) is used for one or more of these functions. External memory could 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.

[0102] Inputs to the components of system 400 may be provided by 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, for example, RF signals transmitted over the air by a broadcaster; (ii) a component (COMP) input terminal (or a set of COMP input terminals); (iii) a universal serial bus (USB) input terminal; and / or (iv) a high-definition multimedia interface (HDMI) input terminal. Figure 4 Other examples not shown include composite video.

[0103] In various examples, the input device of block 445 has associated corresponding input processing elements known in the art. For example, the RF section may be associated with elements suitable for: (i) selecting a desired frequency (also known as selecting a signal, or limiting a signal band to a certain band); (ii) down-converting the selected signal; (iii) band-limiting it again to a narrower band to select, for example, 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 a desired data packet stream. The RF section of various examples includes one or more elements for performing these functions, such as frequency selectors, signal selectors, band limiters, channel selectors, filters, downconverters, demodulators, error correctors, and demultiplexers. The RF section may include tuners that perform 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 baseband. In one set-top box example, the RF section and its associated input processing elements receive RF signals transmitted via a wired (e.g., cable) medium and perform frequency selection by filtering, down-converting, and re-filtering to the desired frequency band. Various examples rearrange the order of the above (and other) components, 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.

[0104] USB and / or HDMI terminals may include corresponding interface processors for connecting system 400 to other electronic devices across USB and / or HDMI connections. It is to be understood that various aspects of input processing, such as Reed-Solomon error correction, may be implemented as needed, for example, within a separate input processing IC or within processor 410. Similarly, aspects of USB or HDMI interface processing may be implemented as needed within a separate interface IC or within processor 410. Demodulated, error-corrected, and demultiplexed streams are provided to various processing elements, including, for example, processor 410 and encoder / decoder 430 operating in conjunction with memory and storage elements, to process the data streams as needed for presentation on an output device.

[0105] Various components of system 400 can be provided within an integrated housing. Within the integrated housing, the various components can be interconnected using a suitable connection arrangement 425 and data can be transmitted therebetween, such as internal buses known in the art, including inter-IC (I2C) buses, wiring, and printed circuit boards.

[0106] 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 via 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, for example, within a wired and / or wireless medium.

[0107] In various examples, data is streamed or otherwise provided to system 400 using a wireless network such as Wi-Fi (e.g., IEEE 802.11 (IEEE refers to the Institute of Electrical and Electronics Engineers)). In these examples, the Wi-Fi signal is received via a communication channel 460 and a communication interface 450 suitable 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 to provide streaming data to system 400, delivering data via an HDMI connection in input box 445. Still other examples use an RF connection in input box 445 to provide streaming data to system 400. As shown 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.

[0108] System 400 can provide output signals to various output devices, including displays 475, speakers 485, and other peripheral devices 495. Displays 475 in various examples include one or more of, for example, touchscreen displays, organic light-emitting diode (OLED) displays, curved displays, and / or foldable displays. Displays 475 can be used in televisions, tablets, laptops, mobile phones, or other devices. Displays 475 can also be integrated with other components (e.g., in smartphones) or standalone (e.g., as an external monitor for a laptop). In various examples, other peripheral devices 495 include one or more of standalone digital video discs (or digital multifunction discs) (DVDs, for both terms), disc players, stereo systems, and / or lighting systems. Various examples use 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.

[0109] In various examples, signaling such as AV links, Consumer Electronics Control (CEC), or other communication protocols that enable device-to-device control with or without user intervention is used to transmit control signals between system 400 and display 475, speaker 485, or other peripheral devices 495. Output devices can be communicatively coupled to system 400 via dedicated connections through their respective 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.

[0110] Alternatively, the display 475 and speaker 485 can 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 the display 475 and speaker 485 are external components, the output signal can be provided via dedicated output connections, including, for example, HDMI ports, USB ports, or COMP outputs.

[0111] The example can be implemented by computer software implemented by processor 410, or by hardware, or by a combination of hardware and software. As a non-limiting example, the example can be implemented by one or more integrated circuits. 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 non-limiting examples. Processor 410 can be of any type suitable for the technical environment and, as a non-limiting example, can encompass one or more of microprocessors, general-purpose computers, special-purpose computers, and processors based on multi-core architectures.

[0112] Various implementations involve decoding. As used in this application, "decoding" can encompass all or part of a process performed on a received coded 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, inverse quantization, inverse transform, and differential decoding. In various examples, such a process also includes, or alternatively includes, processes performed by decoders of the various implementations described in this application, such as adjuncts to multiple QP-specific filtering processes.

[0113] 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. It will be clear, and those skilled in the art, whether the phrase "decoding processing" is intended to specifically refer to a subset of operations or generally to broader decoding processing, based on the specific context of the description.

[0114] Various implementations involve encoding. Similar to the discussion of "decoding" above, the term "encoding" as used in this application can encompass all or part of a process performed on an input video sequence to generate 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 also includes, or alternatively includes, processes performed by encoders of the various implementations described in this application, such as combining multiple QP-specific filtering processes.

[0115] As further examples, in one example, "encoding" refers only to entropy encoding; in another, "encoding" refers only to differential encoding; and in yet another, "encoding" refers to a combination of differential and entropy encoding. It will be clear, and those skilled in the art, whether the phrase "encoding processing" is intended to specifically refer to a subset of operations or generally to broader encoding processing, based on the specific context of the description.

[0116] Note that the grammatical elements used in this article are descriptive terms. Therefore, they do not preclude the use of other grammatical element names.

[0117] 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.

[0118] The implementations and aspects described herein can be implemented, for example, in methods or processes, devices, software programs, data streams, or signals. Even if discussed only in the context of a single implementation (e.g., discussed only as a method), the features discussed can be implemented in other forms (e.g., devices or programs). Devices can be implemented, for example, in appropriate hardware, software, and firmware. Methods can be implemented, for example, in a processor, which 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, mobile phones, portable / personal digital assistants (“PDAs”), and other devices that facilitate information communication between end users.

[0119] The reference to "an example" or "example" or "an implementation" or "implementation" and its variations means that the specific features, structures, characteristics, etc., described in connection with the example are included in at least one example. Therefore, the phrases "in an example" or "in the example" or "in an implementation" or "in the implementation" and any other variations appearing throughout this application do not necessarily all refer to the same example.

[0120] Additionally, this application may involve "determining" various pieces of information. Determining information may include, for example, one or more of estimated information, calculated information, predicted information, or information retrieved from memory. Obtaining may include receiving, retrieving, constructing, generating, and / or determining.

[0121] Furthermore, this application may involve "accessing" various information fragments. Accessing information may include, for example, receiving information, retrieving information (e.g., from memory), storing information, moving information, copying information, calculating information, determining information, predicting information, or estimating information, or one or more of these.

[0122] Additionally, this application may relate to "receiving" various pieces of information. Like "access," receiving is intended to be a broad term. Receiving information may include, for example, accessing information or retrieving information (e.g., from memory) from one or more sources. Furthermore, "receiving" typically relates in one or more ways during operations 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.

[0123] To be clear, for example, in the cases of “A / B,” “A and / or B,” and “at least one of A and B,” the use of any of the following “ / ,” “and / or,” and “at least one of…” is intended to cover selecting only the first listed option (A), or only the second listed option (B), or both options (A and B). As another example, in the cases of “A, B, and / or C” and “at least one of A, B, and C,” this wording is intended to cover selecting only the first listed option (A), or only the second listed option (B), or only the third listed option (C), or only the first 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 all three options (A, B, and C). As will be apparent to those skilled in the art and related fields, this can be extended to as many items as are listed.

[0124] Furthermore, as used herein, the term "signal" refers, among other things, to something indicated to the corresponding decoder. Encoder signals may include, for example, any accompanying terms combined with multiple QP-specific filters. In this way, in the examples, the same parameters are used on both the encoder and decoder sides. Therefore, for example, the encoder may transmit (explicit signaling) specific parameters to the decoder so that the decoder can use the same specific parameters. Conversely, if the decoder already has that specific parameter along with other parameters, then signaling can then be used without transmission (implicit signaling) to simply allow the decoder to know and select that specific parameter. In various examples, bit savings are achieved by avoiding the transmission of any actual functionality. It should be understood that signaling can be done in a variety of ways. For example, in various examples, one or more syntax elements, flags, etc., are used to signal information to the corresponding decoder. While the foregoing refers to the verb form of the term "signal," the term "signal" can also be used as a noun in this document.

[0125] It will be apparent to those skilled in the art that implementations can generate a wide variety of signals formatted to carry, for example, information that can be stored or transmitted. This information may include, for example, instructions for implementing a method or data generated by one of the described implementations. For example, a signal may be formatted to carry a bit stream as described in the example. Such a signal may be formatted, for example, as an electromagnetic wave (e.g., using the radio frequency portion of the spectrum) or a baseband signal. Formatting may include, for example, encoding a data stream and modulating a carrier wave with the encoded data stream. The information carried by the signal may be, for example, analog or digital information. It is well known that signals can be transmitted via a wide variety of wired or wireless links. Signals may be stored on, accessed from, or received from a processor-readable medium.

[0126] This document describes numerous examples. Features of the examples may be provided individually or in any combination across various claim classes and types. Furthermore, examples may include one or more features, devices, or aspects described herein, individually or in any combination, across various claim classes and types. For example, features described herein may be implemented in a bitstream or signal including 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, features described herein may be implemented by creating and / or transmitting and / or receiving and / or decoding a bitstream or signal. For example, features described herein may be implemented by a method, process, device, medium storing instructions, medium storing data, or signal. For example, features described herein may be implemented by a TV, set-top box, mobile phone, tablet computer, or other electronic device that performs decoding. The TV, set-top box, mobile phone, tablet computer, or other electronic device may display (e.g., using a monitor, screen, or other type of display) the obtained image (e.g., an image reconstructed from a residual of a video bitstream). The TV, set-top box, mobile phone, tablet computer, or other electronic device may receive a signal including an encoded image and perform decoding.

[0127] Systems, methods, and means for combining multiple quantization parameter (QP)-specific pre-trained filters during adaptive loop filtering (ALF) are disclosed. A video codec device, which may be, for example, an encoder device or a decoder device, may include at least one processor configured to determine multiple pre-trained ALF QP-specific filter banks. The video codec device can determine QP values ​​and can select multiple ALF QP-specific filter banks based on the QP values. The video codec device can apply each of the multiple ALF QP-specific filter banks to video samples associated with video data to generate corresponding output samples. The video codec device can combine the corresponding output samples.

[0128] In-loop filters can be provided. Block-based intra / inter-frame prediction and transform encoding / decoding, as well as residual quantization, can introduce a variety of artifacts at low to medium bit rates. To reduce these artifacts, in-loop filters such as deblocking filter (DBF), bilateral filter (BIF), sample adaptive offset (SAO), and adaptive loop filter (ALF) can be used.

[0129] Deblocking filtering (DBF) can be designed to smooth discontinuities that may occur along block boundaries. Sample adaptive offset (SAO) can be designed to attenuate artifacts appearing around edges and correct for local average intensity variations (e.g., banding artifacts) using an offset signaled in the bitstream. Bilateral filter (BIF) can be designed to denoise further reconstructed images from artifacts caused by quantization in the transform domain. Adaptive loop filter (ALF) can be determined as the optimal filter on the encoder side according to rate-distortion criteria. ALF filters can be transmitted with the bitstream and can subsequently be retrieved and used on the decoder side.

[0130] In-loop filters can be provided. Example in-loop filters may include a deblocking filter (DBF); a sample adaptive offset (SAO); and an adaptive loop filter (ALF). The deblocking filter can be designed to reduce block discontinuities. The sample adaptive offset can be designed (e.g., primarily designed) to reduce artifacts caused by the quantization of the transform coefficients. The adaptive loop filter and the cross-component adaptive loop filter can be adaptive filters capable of enhancing the reconstructed signal using, for example, Wiener filter coding methods.

[0131] Figure 5 The document describes the workflow of an example loop filter. If the local deblocking condition is met, the luminance and chromaticity reconstructed samples located along the block boundaries can first be filtered with a deblocking filter (DBF). The offset can be locally increased based on the classification using a classifier or an edge classifier with Sample Adaptive Offset (SAO). The adaptive loop filter (ALF) can be performed before the resulting sample values ​​are stored in the reference image cache.

[0132] An adaptive loop filter (ALF) can be provided. An ALF can be an adaptive filter that can be applied to reduce the mean square error (MSE) between the original and reconstructed samples, and can be encoded using, for example, Wiener filter methods.

[0133] ALF filters can be transmitted in the bitstream and decoded on the decoder side before being applied to reconstructed samples. Pre-trained ALF filters can also be hard-encoded at both the encoder and decoder sides.

[0134] ALF can be point-symmetric and DC-neutral with integer coefficients. Figure 6 An example implementation of an ALF filter is described. Figure 6 As shown on the left, ALF can use a 7×7 diamond filter for brightness. Figure 6 As shown on the right, ALF can use a 5×5 diamond filter for chroma.

[0135] It can provide filtering operations. Let... It is to reconstruct the sample, and set This represents its ALF filter value. In the linear implementation of ALF, It can be calculated as follows: in Indicate the filter coefficients, and: in Indicates the same as the i-th coefficient The coordinate offsets corresponding to the associated reconstructed samples.

[0136] In the nonlinear implementation of ALF, equation (1) becomes: in: in It is related to the coefficient The associated limiting parameter, which is determined by the limiting index. Confirmed. Limiting parameters. It can be exported as follows: in Indicate the sample depth, and It can be 0, 1, 2 or 3.

[0137] Integer arithmetic can be used. Let NUM_BITS be the value used to assign ALF filter coefficients. The number of bits represented as a signed integer.

[0138] The ALF filtering operation can be implemented as follows: in and .

[0139] Online filter optimization and offline pre-training can be employed. ALF filter coefficients and clipping indices can be determined at encoding time by, for example, solving the Wiener-Hopf equation to minimize the MSE between the reconstructed samples and their original values ​​at the slice level. If the rate-distortion condition can be satisfied, these coefficients, along with the corresponding clipping indices (if applicable), can be encoded in an adaptive parameter set (APS). For example, an ALF APS might contain a luma filter bank and up to eight chroma filters. Example encoders and decoders can reference up to eight ALF APSs simultaneously.

[0140] The pre-trained luminance filter may have been learned offline and may be hard-coded at both the encoder and decoder sides.

[0141] ALF can be used for luma. ALF for luma can leverage local gradient-based classification to achieve further local adaptation. Therefore, ALF for luma can rely on a filter bank, which can be multiple filters along with a mapping list, with each category of the classification associated with a specific filter in the filter bank. Depending on the classification, geometric filtering transformations, such as, for example, 90-degree rotation, diagonal, or vertical flip, can be applied so that the same filtering coefficients can be applied to different categories / gradient directions.

[0142] There may be many pre-trained luminance filter banks available on the encoder and decoder sides. The encoder can determine (e.g., select) whether it should transmit a luminance filter bank that may have been optimized for the current slice / frame based on rate-distortion criteria.

[0143] At the codec tree unit (CTU) level, the encoder can determine whether to perform ALF and can select a luminance filter bank that can (e.g., should) be used between a pre-trained filter bank and a filter bank that may have already been transmitted.

[0144] In some examples, the chroma ALF may not implement local classification, but it can be used, for example, by using a region adaptive filter instead. Up to eight ALF chroma filters can be available simultaneously on both the encoder and decoder sides, and each chroma CTB can signal which filter to use.

[0145] ALF can be further developed. An intermediate step can be introduced for brightness filtering, which can include filtering the reconstructed samples with a pre-trained filter before using an online-trained adaptive filter. This pre-trained filter can be referred to as a "fixed filter". Figure 7 The workflow of an example filtering process is depicted. As shown in the figure, samples can undergo DBF processing before being processed by one of SAO, BIF, or CCSAO. Then, the resulting samples can be processed by ALF.

[0146] In the example, there may be three fixed filters, which can be labeled as follows: , and Two of them, and It can be based on local classification and can be related to quantization parameters (QP).

[0147] A classification-based fixed filter can be used. Two Laplacian-based classifiers (one for each classification-based fixed filter) can be applied to a 2×2 block. Within each classifier, activity and orientation values ​​can be derived based on vertical, horizontal, and diagonal gradients using a window surrounding each 2×2 block. For each 2×2 block, the mean around the window can be calculated. For each sample within that window, the difference between the sample value and the mean can be calculated. A scaling factor can be determined based on the activity values ​​derived from the Laplacian classifier. The square root of the sum of squared differences can be further quantized using the scaling factor. . The value can be an integer between 0 and 7, inclusive. Let The category index is provided by an 896-class Laplacian classifier based on activity and orientation values ​​using the i-th fixed filter. Final category index. It can be exported as: .

[0148] By using the two exported category indexes and Two double-rhombus fixed filters can be selected from two fixed filter banks. The first fixed filter... This can be applied to the sample values ​​before DBF and the ALF input, where a 13×13 rhombus is applied to the ALF input, and an additional 9×9 rhombus is applied to the sample values ​​before DBF. Second fixed filter. Can be applied to The output of the sample values ​​before DBF is used to form a 9×9 rhombus.

[0149] A fixed ALF filter with quantization parameter (QP) correlation can be used. (Fixed filter) and It may be QP-dependent. For each fixed filter and There may be eight different hard-coded filter banks on the encoder and decoder sides, each applied to a given QP range. Each of these fixed filter banks can use its own 512 pre-trained filter banks. Filter banks can be dedicated to the classifier (e.g., i=0 or 1) and the stated QP range. Figure 8 The indices of the example minimum (910) and maximum (912) filter banks, depending on QP, are depicted. During encoding, given the QP value of the current slice, the encoder can choose between two fixed filter banks, such as... Figure 8 As illustrated, the index of the fixed filter bank selected for each CTU can be signaled in the bitstream.

[0150] A Gaussian fixed filter can be used. A third brightness fixed filter with a diamond 7×7 shape can be used without classification. This fixed filter can be called a Gaussian fixed filter.

[0151] A signaling luminance filter can be used. After fixed filtering, the signaling luminance filter can be applied to the following: ALF input samples; samples before the deblocking filter (DBF); the outputs of two classification-based fixed filters; the output of a Gaussian fixed filter; and residual data.

[0152] The final value of the brightness filter sample can be calculated as follows: in It is the neighboring sample and the current sample The difference in amplitude limits between them; It is the intermediate sample generated by the first fixed filter and the current sample. The difference in amplitude limits between them; It is the intermediate sample generated by the third fixed filter and the current sample The difference in amplitude limits between them; It is a co-located intermediate sample generated by the first fixed filter and the current sample. The difference in amplitude limits between them; It is the co-located intermediate sample generated by the second fixed filter and the current sample The difference in amplitude limits between them; The co-located intermediate samples generated by the third fixed filter and the current sample The difference in amplitude limits between them; It is the neighboring samples before DBF and the current sample The difference in amplitude limits between them; It is the co-located samples before DBF and the current samples The difference in the amplitude limit between them, and among them These are the adjacent residual sample values ​​after amplitude limiting; and It is the residual sample after being filtered by a fixed filter and then clipped. For the residual sample, the fixed filter can be a fixed filter from the first fixed filter bank.

[0153] Figure 9 The filter shape for an example brightness ALF signal notification is depicted. The complete filter shape of the ALF using residual samples as additional input is shown below. Figure 9 As shown.

[0154] A 2x2 ALF classifier can be used as an alternative for luminance. Luminance classification can be extended with additional alternative classifiers. For signal-notified luminance filter banks, a signal flag can be used to indicate whether an alternative classifier has been applied. Geometric transformations are not suitable for alternative band-based classifiers. If a band-based classifier is applied, the sum of sample values ​​for the 2×2 luminance blocks can be calculated. The class index can then be calculated as follows: (11).

[0155] Sample encoder designs can be provided. The encoder can initially select a fixed filter bank for each classifier of each CTU based on distortion comparison.

[0156] Based on those per CTU decisions, statistics can be collected across the entire current slice to derive the coefficients and limiting index of the filter bank for optimal signaling.

[0157] Based on the signaling cost of the new optimal filter bank and the corresponding quality gain on the slice, the encoder can determine (e.g., decide) to signal the new optimal filter bank in the ALF APS. In the example, up to four luminance filter banks can be signaled in the same ALF APS.

[0158] Each CTU can signal which filter bank it can use from each available filter bank (e.g., the set of each filter bank for all reference ALF APS).

[0159] Multiple pre-trained QP-specific filter banks may be available on the encoder and decoder sides. However, only one filter bank may have been used, and the corresponding index may have already been signaled in the bitstream. Improvements can be made.

[0160] In the example, the Adaptive In-Loop Filtering (ALF) framework can be presented as two consecutive steps: a first step using a pre-trained, QP-specific "fixed" filter bank (e.g., filters that may have been learned offline for a given QP range and can be hard-coded at both the encoder and decoder sides); and a second filtering step using filters determined at encoding time and transmitted in the bitstream. Within this framework, for a given fixed filter, multiple QP-qualified fixed filter banks can be applied, and the corresponding results can be combined into an adaptive (e.g., ultimately adaptive) filtering result.

[0161] Figure 10An example processing for combining QP-qualified filters is described. In step 1110, several QP-specific pre-trained filters can be determined to be available on both the encoder and decoder sides. Based on the current QP value, in step 1112, a subset of QP-qualified filters can be selected and applied to the adaptively filtered input samples. In step 1114, the outputs of the selected QP-qualified filters can be combined to generate an adaptively filtered output.

[0162] In the example, each CTU may not have a fixed filter bank index for signaling notifications.

[0163] There may be several example implementations to combine the corresponding results of a qualified fixed filter. This article may describe different implementations.

[0164] In the example, the number of QP-qualified fixed filter banks can be equal to 2.

[0165] Considering a given fixed filter, two QP-qualified fixed filter banks can be applied, and in addition to the ALF syntax elements specifying the signaling filter to be used, the weighting factor determined at encoding time can also be signaled to each CTU in the bitstream.

[0166] Signals in the bitstream can be used to indicate whether a conventional ALF process or a combination method is used.

[0167] One or more of the following example implementations can be adopted: fixed filter fusion per CTU, wherein each CTU signals one or more weighting factors, wherein two weighting factors (e.g., one for each fixed filter) or a single weighting factor can be used for two fixed filters; one or more additional taps in the signaled filter shape, wherein the variant can depend on the affected fixed filter; unclassified fixed filtering, wherein the filter bank can be reduced to a single filter; combining two or more QP-qualified filters; fixed filter combination with derived weighting factors, wherein lookup tables or direct calculation can be used.

[0168] A video encoding / decoding approach can be employed where Adaptive In-Loop Filtering (ALF) can be presented as two consecutive steps: a first step using a pre-trained, QP-specific "fixed" filter bank (e.g., filters trained offline for a given QP range and hard-coded at both the encoder and decoder sides); and a second filtering step using the outputs of the fixed filters. The filters can be determined at encoding time and included in the video data (e.g., transmitted in a bitstream).

[0169] In the example, given a fixed filter, multiple QP-qualified fixed filter banks can be applied. At least one fixed filter bank index can be determined, for example, as follows: in Indicates the function for rounding down.

[0170] In the example, the number of QP-qualified fixed filter banks can be equal to 2. The index of the QP-qualified fixed filter banks can be, for example... and ,or and .

[0171] The example implementation combines the outputs of a QP-qualified fixed filter bank into the final ALF result.

[0172] Fixed filter fusion can be employed using weighting factors for each CTU. In the example, the result of combining QP-qualified fixed filter banks can depend on signaling of at least one weighting factor at the CTU level. The weighting factor can range from 0 to 1, inclusive, and can take intermediate values. The total number of values ​​can be predetermined.

[0173] In the example, at least one weighting factor can be negative and / or at least one weighting factor can be better than (e.g., greater than) 1.

[0174] In one example, the weighting factor can be encoded as an unsigned integer with a given number of bits. In another example, the weighting factor can be encoded using a variable-length code. In yet another example, the weighting factor can be binary and encoded with its own context using Context Adaptive Binary Arithmetic Coding (CABAC).

[0175] For CTUs or CTU groups with the ALF flag set to off, signaling to the weighting factor may not be necessary (e.g., it may not be required).

[0176] In the example, a signal can be sent at the CTU level to notify a single weighting factor. .

[0177] set up and These respectively indicate the results of adaptive filtering for signal notification using a lower fixed filter bank index and a higher fixed filter bank index. Regardless of the classifier, the same index can be used for both fixed filters (e.g., ...). and The weighting factors can be combined to obtain the results of a QP-qualified fixed filter bank as follows: .

[0178] One weighting factor can be used for each fixed filter. In the example, the two weighting factors can be signaled at the CTU level. and ,in control The merging of QP-qualified fixed filter banks, and control The merging of QP-qualified fixed filter banks.

[0179] The output of the ALF process can be defined as follows: .

[0180] in: Indicates the use of a lower fixed filter bank index for fixed filters. and fixed filter The results of adaptive filtering for both signal notifications; Indicates the use of a lower fixed filter bank index for fixed filters. and higher fixed filter bank index for fixed filters The result of adaptive filtering for signal notification; Indicates the use of a higher fixed filter bank index for fixed filters. and lower fixed filter bank index for fixed filters The result of adaptive filtering for signal notification; and Indicates the use of a higher fixed filter bank index for fixed filters. and fixed filter The result of adaptive filtering for both signaling methods. In the example, the second weighting factor... It can be relative to the first weighting factor Perform differential encoding and decoding.

[0181] Processing can be performed on the encoder side. For each CTU, the encoder can jointly determine one or more optimal weighting factors for combining a fixed filter bank that is QP qualified with the optimal filter bank for signal notification. This can be performed, for example, by testing each combination of filter banks available for each signal notification and each allowed weighting factor value.

[0182] Tap pairs for QP-qualified fixed filter outputs can be used in the signaling filter. In the example, the signaling adaptive filter can be extended with at least one additional tap. At least one tap pair can be applied as follows: a first tap can be applied to the output of the QP-qualified fixed filter selected when using a lower fixed filter bank index; a second tap can be applied to the output of the QP-qualified fixed filter selected when using a higher fixed filter bank index.

[0183] In the nonlinear example, a "tap" can refer to a filter coefficient and its corresponding limiting index. In the linear case, a "tap" can refer to a filter coefficient.

[0184] Additional filter coefficients and (if applicable) additional clipping indices can be determined at encoding time, for example, by using iterative optimization methods that rely on solving the Wiener-Hopf system equations at the slice level.

[0185] A single additional tap can be used for a fixed filter. In the example, a single fixed filter, for example, only fixed filter number 1 (#1), can be applied to two QP-qualified fixed filter banks.

[0186] In the example, the adaptive filter that signals can have 37 taps. Taps numbered 0 through 9 can be applied to the BIF / SAO output samples. Taps numbered 10 through 27 and 30 can be applied to the output samples of fixed filter number 0. Taps 31 and 32 can be applied to the QP-qualified fixed filters of fixed filter number 1 at lower and higher indices, respectively. Taps 28-29 and 34 can be applied to the samples before DBF. Taps 33 and 35 can be applied to the residual samples and the filtered residual samples, respectively. Tap 36 can be applied to the output samples of fixed filter 2. Figure 11 An example of this adaptive filter shape for 37-tap signal notification is provided. Figure 11 An example depicting the shape of an adaptive filter with 37 taps for signal notification is shown, which presents a tap pair for a QP-qualified fixed filter bank with fixed filter number 1.

[0187] In the example, the signaling filter can have 40 taps, where taps numbered 0 through 9 can be applied to the BIF / SAO output samples. Taps 10-27 and 34 can be applied to the output samples of fixed filter number 0. Taps 35 and 36 can be applied to the QP-qualified fixed filters of fixed filter number 1, with lower and higher indices respectively. Taps 28-31 and 39 can be applied to the output samples of fixed filter number 2. Taps 32-33 and 37 can be applied to samples prior to DBF. Tap 38 can be applied to the residual samples. Figure 12An example of the shape of this adaptive filter for 40-tap hair signal notification is depicted in the image. Figure 12 An example depicting the shape of an adaptive filter with 40 taps for signal notification is shown, which presents a tap pair for a QP-qualified fixed filter bank with fixed filter number 1.

[0188] In the example, the adaptive filter that sends the signal notification can present a tap pair for both fixed filter number 0 and fixed filter number 1.

[0189] In the example, consider that the fixed filter used to combine QP-qualified filters may not depend on the local sample classification. The classification can present a single class for each sample, and the filter bank can be reduced to a single filter.

[0190] In the example, two or more QP-qualified filters can be combined. In the example, three or more QP-qualified fixed filter banks can be combined. If three fixed filter banks are combined, the indices of the QP-qualified fixed filter banks can be, for example, , and .

[0191] In examples where weighting factors are signaled at the CTU level, CTU group level, slice / picture level, or sequence level, the number of weighting factors can be equal to the number of QP-qualified filters to be combined minus one. For example, in the case of three QP-qualified filters, if , and The results of adaptive filtering for signal notification using lower, intermediate, and higher fixed filter bank indices are indicated separately, and the combination uses two weighting factors. and As shown below: .

[0192] In the example, additional taps can be used in the signaled adaptive filter shape. If a fixed filter combination is performed directly during the signaled filter optimization step, the combination can depend on the tap tuple. For example, in the case of three QP-qualified filters, the result of combining their respective filters can depend on the tap triplet.

[0193] A fixed filter combination with derived weighting factors (e.g., without signaling) can be provided. In the example, the result of a QP-qualified fixed filter bank can rely on weighting factors derived from information available from the decoder. In this example, the syntactic cost of adaptive filtering can be reduced because there is no need to signal the weighting factors.

[0194] A lookup table (LUT) can be used. In the example, the weighting factor can be obtained from the lookup table (LUT). The size of the LUT can be equal to the divisor (e.g., the denominator) in the integer division of equation (12).

[0195] Tables 1 and 2 provide examples of this type of LUT: index Weighting factor 0 1.0 1 0.75 2 0.5 3 0.25 Table 1: Example of a weighted factor lookup table. index Weighting factor 0 0.0 1 0.25 2 0.5 3 0.75 Table 2: Another example of a weighted factor lookup table.

[0196] Accessing the LUT based on the QP value is shown below: or: in Indicates the function for rounding down.

[0197] In the example, a weighting factor can be calculated. This calculation may involve, for example, the QP value.

[0198] In the example, if N=2, then the weighting factor... It can be exported as follows: or: in It can be a real or rational number depending on QP, and can be stored as a floating-point or fixed-point number, which can be defined, for example: in Indicates the function for rounding down.

[0199] Weighting factor The results can be used to combine QP-qualified fixed filter banks, for example, as shown in equation (13).

[0200] Although the features and elements have been described above in specific combinations, those skilled in the art will appreciate that each feature or element can be used alone 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 over 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 storage devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROMs and digital versatile discs (DVDs). A processor associated with the software can be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A video decoding device, comprising: The processor is configured to at least: Determine the quantization parameter (QP) value; Based on the QP value, select multiple adaptive loop filter (ALF) QP-specific filter banks; Each of the plurality of ALF QP specific filter banks is applied to the video sample associated with the video data to generate the corresponding output sample; as well as Combine the corresponding output samples.

2. The video decoding device according to claim 1, The plurality of ALF QP-specific filter banks includes two ALF QP-specific filter banks.

3. The video decoding device according to claim 2, The processor is further configured as follows: Determine the appropriate weighting factor for each codec tree unit (CTU) included in the video data.

4. The video decoding device according to claim 3, The processor configured to combine the corresponding output samples is further configured to apply the corresponding weighting factor to the corresponding one of the corresponding output samples.

5. The video decoding device according to claim 1, The processor configured to combine the corresponding output samples is further configured to apply an adaptive filter with at least one added tap for signaling notification.

6. The video decoding device according to claim 2, The processor is further configured as follows: The first and second weighting factors are derived based on the QP value, and The processor configured to combine the corresponding output samples is further configured to apply a first weighting factor to the first of the corresponding output samples and apply a second weighting factor to the second of the corresponding output samples.

7. A video decoding method, comprising: The processor is configured to at least: Determine the quantization parameter (QP) value; Based on the QP value, select multiple adaptive loop filter (ALF) QP-specific filter banks; Each of the plurality of ALF QP specific filter banks is applied to the video sample associated with the video data to generate the corresponding output sample; as well as Combine the corresponding output samples.

8. The method according to claim 7, The plurality of ALF QP-specific filter banks includes two ALF QP-specific filter banks.

9. The method of claim 8, wherein the method further comprises: Determine the appropriate weighting factor for each codec tree unit (CTU) included in the video data.

10. The method according to claim 9, The combination of the corresponding output samples further includes applying the corresponding weighting factor to the corresponding one of the corresponding output samples.

11. The method according to claim 7, The combination of the corresponding output samples includes the application of an adaptive filter with at least one added tap for signal notification.

12. The method of claim 8, wherein the method further comprises: The first and second weighting factors are derived based on the QP value, and The combination of the corresponding output samples includes applying a first weighting factor to the first of the corresponding output samples and applying a second weighting factor to the second of the corresponding output samples.

13. A video encoding device, comprising: The processor is configured to at least: Determine the quantization parameter (QP) value; Based on the QP value, select multiple adaptive loop filter (ALF) QP-specific filter banks; Each of the plurality of ALF QP specific filter banks is applied to the video sample associated with the video data to generate the corresponding output sample; as well as Combine the corresponding output samples.

14. The video encoding device according to claim 13, The plurality of ALF QP-specific filter banks includes two ALF QP-specific filter banks.

15. The video encoding device according to claim 14, The processor is further configured as follows: Determine the appropriate weighting factor for each codec tree unit (CTU) included in the video data.

16. The video encoding device according to claim 15, The processor is further configured to send a corresponding weighting factor for each CTU included in the video data.

17. The video encoding device according to claim 15, The processor configured to combine the corresponding output samples is further configured to apply the corresponding weighting factor to the corresponding one of the corresponding output samples.

18. The video encoding device according to claim 13, The processor is further configured to determine an adaptive filter with at least one added tap; and The processor configured to combine the corresponding output samples is further configured to apply an adaptive filter with at least one added tap.

19. The video encoding device according to claim 18, The processor is further configured to send an instruction for an adaptive filter with at least one added tap.

20. The video encoding device according to claim 14, The processor is further configured as follows: The first and second weighting factors are derived based on the QP value, and The processor configured to combine the corresponding output samples is further configured to apply a first weighting factor to the first of the corresponding output samples and apply a second weighting factor to the second of the corresponding output samples.

21. A video coding method, comprising: Determine the quantization parameter (QP) value; Based on the QP value, select multiple adaptive loop filter (ALF) QP-specific filter banks; Each of the plurality of ALF QP specific filter banks is applied to the video sample associated with the video data to generate the corresponding output sample; as well as Combine the corresponding output samples.

22. The method according to claim 21, The plurality of ALF QP-specific filter banks includes two ALF QP-specific filter banks.

23. The method of claim 22, further comprising: Determine the appropriate weighting factor for each codec tree unit (CTU) included in the video data.

24. The method of claim 23, further comprising: Send the corresponding weighting factor for each CTU included in the video data.

25. The method according to claim 23, The combination of the corresponding output samples further includes applying the corresponding weighting factor to the corresponding one of the corresponding output samples.

26. The method of claim 21, further comprising: Determine an adaptive filter with at least one added tap. The combination of the corresponding output samples further includes the application of an adaptive filter with at least one added tap.

27. The method of claim 26, further comprising: Send an instruction for an adaptive filter with at least one added tap.

28. The method of claim 22, further comprising: The first and second weighting factors are derived based on the QP value, and The combination of corresponding output samples further includes applying a first weighting factor to the first of the corresponding output samples and applying a second weighting factor to the second of the corresponding output samples.

29. A computer program product stored on a computer-readable medium and comprising program code instructions, which, when executed by a processor, are configured to perform the method steps according to any one of claims 7 to 12 and 21 to 28.

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