Template-Based Intra Mode Derivation with Wide-Angle Intra Prediction

Abstract

A system, method, and means for performing video coding to derive an intra-prediction mode for predicting a current block using TIMD with wide-angle intra prediction (WAIP) are disclosed. A Most Probable Mode (MPM) list associated with the current block may be obtained. A test list of intra-prediction modes may be determined from the MPM list. A first intra-prediction mode may be tested, and the first intra-prediction mode may be excluded from the test list or not allowed to be tested due to a WAIP substitution. A prediction for the current block may be generated based on the tested intra-prediction mode. The current block may be decoded using the prediction.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of European Provisional Patent Application No. 22305511.2, filed April 8, 2022, the contents of which are hereby incorporated by reference. [Background technology]

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

[0003] Systems, methods, and means for performing video coding to derive an intra-prediction mode for predicting a current block using template-based intra mode derivation (TIMD) with wide angle intra prediction (WAIP) are disclosed. A most probable mode (MPM) list associated with the current block may be obtained. A test list of intra-prediction modes may be determined from the MPM list. A first intra-prediction mode may be tested, and the first intra-prediction mode may be excluded from the test list or may not be allowed to be tested due to wide angle intra prediction (WAIP) substitution. A prediction for the current block may be generated based on the tested intra-prediction mode. The current block may be processed (e.g., encoded and / or decoded) using the prediction.

[0004] A second intra-prediction mode may be tested, and the second intra-prediction mode may be included in a test list. A prediction for the current block may be generated based on the tested first intra-prediction mode and the tested second intra-prediction mode test. The testing of the first intra-prediction mode may occur prior to the determination of the test list. The current block may be associated with a first shape, and the first intra-prediction mode may be associated with a second shape.

[0005] The first shape may be a rectangle and the second shape may be a square. Adjacent sides of the first shape may have different lengths. The first shape may be a square and the second shape may be a rectangle. Adjacent sides of the second shape may have different lengths.

[0006] Multiple indexes of intra-prediction modes may be generated, and the multiple indexes of the intra-prediction modes may be used to generate a prediction for the current block.

[0007] Weights of multiple indices of intra-prediction modes may be calculated, and at least one of the weights may be a sum of absolute transform difference (SATD). A prediction for the current block may be generated based on a subset of the indexes of intra-prediction modes having the smallest predicted SATD from the multiple indices of intra-prediction modes.

[0008] The generated prediction may be further based on the calculated weights. The calculated weights may include a first calculated weight associated with the tested first intra-prediction mode and a second weight associated with the tested second intra-prediction mode. For the first intra-prediction mode, at least one decoded reference sample may be added.

[0009] The systems, methods, and means described herein may involve a decoder. In some embodiments, the systems, methods, and means described herein may involve an encoder. In some embodiments, the systems, methods, and means described herein may involve a signal (e.g., from an encoder and / or received by a decoder). A computer-readable medium may include instructions for causing one or more processors to perform the methods described herein. A computer program product may include instructions that, when executed by one or more processors, may cause the one or more processors to perform the methods described herein. [Brief description of the drawings]

[0010] [Figure 1A] FIG. 1 is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] 1B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system shown in FIG. 1A, in accordance with one embodiment. [Figure 1C] FIG. 1B is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communication system shown in FIG. 1A, according to one embodiment. [Figure 1D] FIG. 1B is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communication system shown in FIG. 1A, according to one embodiment. [Diagram 2] 1 illustrates an exemplary video encoder. [Diagram 3] 1 illustrates an exemplary video decoder. [Figure 4] 1 illustrates an example of a system in which various aspects and embodiments may be implemented. [Diagram 5]Illustrates an example of an intra-prediction mode in a video coding toolset (eg, versatile video coding (VVC) and enhanced compression model (ECM)). [Figure 6A] 1 illustrates an exemplary derivation of a Most Probable Mode (MPM) list for a current luma coding block (CB) belonging to an intra slice in an ECM. [Figure 6B] 1 illustrates an exemplary derivation of a Most Probable Mode (MPM) list for a current luma coding block (CB) belonging to an intra slice in an ECM. [Figure 7A] 13 illustrates an example of signaling a selected intra-prediction mode for predicting a current luminance CB in an ECM. [Figure 7B] 13 illustrates an example of signaling a selected intra-prediction mode for predicting a current luminance CB in an ECM. [Figure 8] 1 illustrates an example of signaling a selected intra-prediction mode for predicting a current pair of chrominance CB in an ECM. [Figure 9A] 1 illustrates an example relationship between the range of a set of decoded reference samples around a current WxH block to be predicted and the range of allowed intra-prediction angles. [Figure 9B] 1 illustrates an example relationship between the range of a set of decoded reference samples around a current WxH block to be predicted and the range of allowed intra-prediction angles. [Figure 10] 1 illustrates an example of an angle mode being replaced by a wide angle mode for a non-square block whose width is greater than its height. [Figure 11A] Illustrates an example of a template of current luminance CB and a decoded reference sample of that template. [Figure 11B]Illustrates an example of a template of current luminance CB and a decoded reference sample of that template. [Figure 11C] Illustrates an example of a template of current luminance CB and a decoded reference sample of that template. [Figure 12A] 1 illustrates an example of a range of directions added by wide-angle intra prediction (WAIP) and a range of directions replaced by WAIP. [Figure 12B] 1 illustrates an example of a range of directions added by wide-angle intra prediction (WAIP) and a range of directions replaced by WAIP. [Figure 13] Illustrates an example of the range of directions added by WAIP and the range of directions replaced by WAIP when the reference samples for the current block are square. [Figure 14] Illustrates an example of the range of directions added by WAIP and the range of directions replaced by WAIP when the reference samples for the current block are rectangular. [Figure 15] 1 illustrates an example of a template-based intra mode derivation (TIMD) derivation procedure for a current block to be predicted when one or more additional directional intra-prediction modes are allowed. [Figure 16] 1 illustrates an example of a TIMD derivation procedure for a current block to be predicted when one or more additional directional intra-prediction modes are allowed. [Figure 17] 1 illustrates an example of a TIMD derivation procedure for a current block to be predicted when one or more additional directional intra-prediction modes are allowed. [Figure 18A] For example, an example of the addition of decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxH block to be predicted, W>H, when one or more directional intra-prediction modes replaced by WAIP are allowed is illustrated. [Figure 18B]For example, an example of the addition of decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxH block to be predicted, W>H, when one or more directional intra-prediction modes replaced by WAIP are allowed is illustrated. [Figure 18C] For example, an example of the addition of decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxH block to be predicted, W>H, when one or more directional intra-prediction modes replaced by WAIP are allowed is illustrated. [Figure 19A] For example, an example of adding decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxH block to be predicted, H>W, when one or more directional intra-prediction modes replaced by WAIP are allowed is illustrated. [Figure 19B] For example, an example of adding decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxH block to be predicted, H>W, when one or more directional intra-prediction modes replaced by WAIP are allowed is illustrated. [Figure 19C] For example, an example of adding decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxH block to be predicted, H>W, when one or more directional intra-prediction modes replaced by WAIP are allowed is illustrated. [Figure 20A] For example, an example of the addition of decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxH block to be predicted, W>H, when one or more directional intra-prediction modes replaced by WAIP are allowed is illustrated. [Figure 20B] For example, an example of the addition of decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxH block to be predicted, W>H, when one or more directional intra-prediction modes replaced by WAIP are allowed is illustrated. [Figure 20C]For example, an example of the addition of decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxH block to be predicted, W>H, when one or more directional intra-prediction modes replaced by WAIP are allowed is illustrated. [Figure 21A] For example, an example of adding decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxH block to be predicted, H>W, when one or more directional intra-prediction modes replaced by WAIP are allowed is illustrated. [Figure 21B] For example, an example of adding decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxH block to be predicted, H>W, when one or more directional intra-prediction modes replaced by WAIP are allowed is illustrated. [Figure 21C] For example, an example of adding decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxH block to be predicted, H>W, when one or more directional intra-prediction modes replaced by WAIP are allowed is illustrated. [Figure 22A] 13 illustrates an example of adding decoded reference samples during TIMD derivation and prediction via TIMD for a square WxW block to be predicted. [Figure 22B] 13 illustrates an example of adding decoded reference samples during TIMD derivation and prediction via TIMD for a square WxW block to be predicted. [Figure 22C] 13 illustrates an example of adding decoded reference samples during TIMD derivation and prediction via TIMD for a square WxW block to be predicted. [Figure 23A] 13 illustrates an example of adding decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxW block to be predicted. [Figure 23B]13 illustrates an example of adding decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxW block to be predicted. [Figure 23C] 13 illustrates an example of adding decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxW block to be predicted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, in which:

[0012] 1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. Communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcasts, etc., to multiple wireless users. Communications system 100 may enable multiple wireless users to access such content through sharing of system resources, including wireless bandwidth. For example, the communications system 100 may use one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0013] 1A, communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, public switched telephone network (PSTN) 108, Internet 110, and other networks 112, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a "station" and / or "STA," may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, wireless paging, mobile phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (loT) devices, watches or other wearable head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., for remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated processing chain context), consumer electronics devices, devices operating in commercial and / or industrial wireless networks, and the like. Any of the UEs 102a, 102b, 102c, and 102d may be referred to interchangeably as a WTRU.

[0014] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base station transceiver station (BTS), a Node B, an eNode B, a Home Node B, a Home eNode B, a gNB, an NR Node B, a site controller, an access point (AP), a wireless router, etc. Although the base stations 114a, 114b are each illustrated as a single element, it will be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0015] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), a relay node, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as cells (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide wireless service coverage for a particular 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 the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell, for example, using beamforming to transmit and / or receive signals in a desired spatial direction.

[0016] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d via an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0017] More specifically, as noted above, the communications system 100 may be a multiple access system, but may use one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base stations 114a and the WTRUs 102a, 102b, 102c in the RAN 104 / 113 may implement a radio technology, such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA may include communications protocols such as High-Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High-Speed ​​Uplink Packet Access (HSUPA).

[0018] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0019] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology, such as New Radio (NR) radio access, which may establish the air interface 116 using NR technology.

[0020] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, e.g., using dual connectivity (DC) principles. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0021] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology such as IEEE 802.11 (i.e., Wireless Fidelity, WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access, WiMAX), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), or the like.

[0022] 1A may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a localized area, such as an office, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, etc. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology, such as IEEE 802.11, to establish a wireless local area network (WLAN). In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology, such as IEEE 802.15, to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may establish a picocell or a femtocell using a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.). As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not need to access the Internet 110 via the CN 106 / 115.

[0023] The RAN 104 / 113 may communicate with the CN 106 / 115, which may be any type of network configured to provide voice, data, application, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have various quality of service (QoS) requirements, such as, for example, different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high level security functions such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may communicate directly or indirectly with other RANs that use the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, the CN 106 / 115 may also communicate with another RAN (not shown) using GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0024] The CN 106 / 115 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network providing plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as transmission control protocol (TCP), user datagram protocol (UDP), and / or internet protocol (IP) of the TCP / IP Internet protocol suite. The networks 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may use the same RAT as the RANs 104 / 113 or a different RAT.

[0025] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a, which may employ a cellular-based wireless technology, and a base station 114b, which may employ an IEEE 802 wireless technology.

[0026] Figure 1B is a system diagram illustrating an example WTRU 102. As shown in Figure 1B, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be understood that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0027] The 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. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although FIG. 1B illustrates the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0028] The transmit / receive element 122 may be configured to transmit or receive signals to or from a base station (e.g., base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0029] 1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0030] The transceiver 120 may be configured to modulate signals transmitted by the transmit / receive element 122 and demodulate signals received by the transmit / receive element 122. As mentioned above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as, for example, NR and IEEE 802.11.

[0031] The processor 118 of the WTRU 102 may be coupled to and may receive user-entered data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as non-removable memory 130 and / or removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, etc. In other embodiments, the processor 118 may access information from and store data in memory that is not physically located on the WTRU 102, such as on a server or home computer (not shown).

[0032] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control the power to other components in the WTRU 102. The power source 134 may be any suitable device for providing power to the WTRU 102. For example, the power source 134 may include one or more dry batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0033] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may obtain location information by way of any suitable position determination method while remaining consistent with an embodiment.

[0034] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, which may be one or more of a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor, a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0035] The WTRU 102 may include a full-duplex radio where transmission and reception of some or all of the signals associated with a particular subframe (e.g., for both the UL (e.g., for transmission) and the downlink (e.g., for reception) may be parallel and / or simultaneous. The full-duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., via a separate processor (not shown) or via the processor 118). In one embodiment, the WRTU 102 may include a half-duplex radio for transmission and reception of either some or all of the signals (e.g., associated with a particular subframe for either the UL (e.g., for transmission) or the downlink (e.g., for reception)).

[0036] 1C is a system diagram illustrating the RAN 104 and the CN 106, according to one embodiment. As mentioned above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also communicate with the CN 106.

[0037] The RAN 104 may include eNodeBs 160a, 160b, 160c, although it will be understood that the RAN 104 may include any number of eNodeBs while remaining consistent with an embodiment. The eNodeBs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the eNodeBs 160a, 160b, 160c may implement MIMO technology. Thus, the eNodeB 160a may, for example, use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0038] Each of the eNodeBs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, etc. As shown in FIG 1C, the eNodeBs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0039] 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. Although each of the foregoing elements is illustrated 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.

[0040] The MME 162 may be connected to each of the eNodeBs 162a, 162b, 162c in the RAN 104 via an S1 interface and may function as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attachment of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0041] The SGW 164 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-eNodeB handover, triggering paging when DL data is available to the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0042] The SGW 164 may be connected to a PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0043] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include or communicate with an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0044] Although the WTRU is depicted in FIGS. 1A-1D as a wireless terminal, in certain representative embodiments, it is contemplated that such a terminal may use a wired communications interface (e.g., temporarily or permanently) with the communications network.

[0045] In an exemplary embodiment, the other network 112 may be a WLAN.

[0046] A WLAN in infrastructure Basic Service Set (BSS) mode may have an access point (AP) of the BSS and one or more stations (STAs) associated with the AP. The AP may have access or interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic into and / or out of the BSS. Traffic originating from outside the BSS to the STA may arrive through the AP and be delivered to the STA. Traffic originating from the STA to a destination outside the BSS may be sent to the AP to be delivered to the respective destination. Traffic between STAs within the BSS may be sent, for example, through the AP, where the source STA may send traffic to the AP, which may deliver the traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between (e.g., directly between) the source STA and the destination STA using a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may be referred to herein as an "ad-hoc" communication mode.

[0047] When using an 802.11ac infrastructure mode of operation or a similar mode of operation, an AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width that is dynamically set via signaling. The primary channel may be the operating channel of the BSS, but may be used by STAs to establish a connection with the AP. In certain representative embodiments, for example, in an 802.11 system, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented. With CSMA / CA, STAs (e.g., all STAs), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0048] A High Throughput (HT) STA may use a 40 MHz wide channel for communication, which may be formed, for example, through a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels.

[0049] A Very High Throughput (VHT) STA may support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. A 40 MHz and / or 80 MHz channel may be formed by combining multiple contiguous 20 MHz channels. A 160 MHz channel may be formed by combining eight contiguous 20 MHz channels or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, after channel encoding, the data may pass through a segment parser that may split the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time domain processing may be performed separately on each stream. The streams may be mapped to two 80 MHz channels and the data may be transmitted by the transmitting STA. At the receiver of the receiving STA, the operations described above for the 80+80 configuration may be reversed and the combined data may be transmitted to the Medium Access Control (MAC).

[0050] Sub-1 GHz operating modes are supported by 802.11af and 802.11ah. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in TV White Space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support meter-type control / machine-type communication, such as MTC devices in macro coverage areas. MTC devices may have limited capabilities, including certain capabilities, for example, support for (e.g., support only for) certain and / or limited bandwidths. MTC devices may include batteries with above-threshold battery life (e.g., to maintain very long battery life).

[0051] WLAN systems that may support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that may be designated as a primary channel. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be configured and / or limited by the STAs among all STAs operating in the BSS that support the smallest bandwidth operating mode. In an 802.11ah embodiment, the primary channel may be 1 MHz wide for STAs (e.g., MTC-type devices) that support (e.g., only) the 1 MHz mode, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) configuration may depend on the status of the primary channel. For example, if the primary channel is active due to a STA (that only supports the 1 MHz mode of operation) transmitting to the AP, the entire available frequency band may be considered active even though most of the frequency band may remain dormant and available.

[0052] In the United States, the available frequency bands that can be used by 802.11ah are 902MHz to 928MHz. In South Korea, the available frequency bands are 917.5MHz to 923.5MHz. In Japan, the available frequency bands are 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz depending on the country code.

[0053] 1D is a system diagram illustrating the RAN 113 and the CN 115, according to one embodiment. As mentioned above, the RAN 113 may employ NR radio technology and communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also communicate with the CN 115.

[0054] The RAN 113 may include gNBs 180a, 180b, 180c, although it will be understood that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 108b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may transmit and / or receive wireless signals to and from the WTRU 102a, for example, using multiple antennas. In one embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In one embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNBs 180a and 180b (and / or gNB 180c).

[0055] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of different or scalable lengths (e.g., including different numbers of OFDM symbols and / or lasting different lengths of absolute time).

[0056] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c without accessing another RAN (e.g., eNodeBs 160a, 160b, 160c, etc.). In a standalone configuration, the WTRUs 102a, 102b, 102c may utilize one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in unlicensed bands. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate with and connect to a gNB 180a, 180b, 180c while also communicating with and connecting to another RAN, such as an eNodeB 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeBs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0057] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data to User Plane Functions (UPFs) 184a, 184b, routing of control plane information to Access and Mobility Management Functions (AMFs) 182a, 182b, etc. As shown in FIG. 1D, the gNBs 180a, 180b, 180c may communicate with each other via an Xn interface.

[0058] 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. Although each of the foregoing elements is illustrated 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.

[0059] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may function as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, managing registration areas, terminating NAS signaling, mobility management, etc. Network slicing may be used by the AMF 182a, 182b to customize the CN support of the WTRUs 102a, 102b, 102c based on the type of service utilizing the WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, etc. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0060] The SMFs 183a, 183b may be connected to the AMFs 182a, 182b in the CN 115 via an N11 interface. The SMFs 183a, 183b may also be connected to the UPFs 184a, 184b in the CN 115 via an N4 interface. The SMFs 183a, 183b may select and control the UPFs 184a, 184b and configure the routing of traffic through the UPFs 184a, 184b. The SMFs 183a, 183b may perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0061] The UPFs 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPFs 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, etc.

[0062] The CN 115 may facilitate communication with other networks. For example, the CN 115 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b through the UPFs 184a, 184b via an N3 interface to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

[0063] 1A-1D and the corresponding description thereof, one or more or all of the functions described herein with respect to one or more of the WTRUs 102a-d, base stations 114a-b, eNodeBs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-b, UPFs 184a-b, SMFs 183a-b, DNs 185a-b, and / or any other devices described herein may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0064] The emulation device may be designed to perform one or more tests of other devices in a lab environment and / or an operator network environment. For example, one or more emulation devices may perform one or more or all functions while fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices in the communication network. One or more emulation devices may perform one or more or all functions while temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for testing purposes and / or may perform the tests using terrestrial wireless communication.

[0065] The one or more emulation devices may perform one or more functions, inclusive, while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in test scenarios in a test lab and / or in an undeployed (e.g., test) wired and / or wireless communication network to perform testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (which may include, for example, one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0066] This application describes various aspects, including tools, features, examples, models, techniques, and the like. Many of these aspects are described with specificity and often in a potentially limiting manner to at least illustrate their individual characteristics. However, this is for purposes of clarity of description and does not limit the applicability or scope of the aspects. In fact, all of the different aspects may be combined and interchanged to provide further aspects. Moreover, these aspects may likewise be combined and interchanged with aspects described in prior applications.

[0067] Aspects described and contemplated in this application may be implemented in many different forms. Figures 5-23 described herein may provide some examples, but other examples are contemplated. Discussion of Figures 5-23 is not intended to limit the scope of implementations. At least one of the above aspects generally relates to video encoding and decoding, and at least one other aspect generally relates to transmitting a generated or encoded bitstream. These and other aspects may be implemented as a method, an apparatus, a computer-readable storage medium having stored thereon instructions for encoding or decoding video data according to any of the described methods, and / or a computer-readable storage medium having stored thereon a bitstream generated according to any of the described methods.

[0068] In this application, the terms "reconstructed" and "decoded" may be used interchangeably, the terms "pixel" and "sample" may be used interchangeably, and the terms "image", "picture", and "frame" may be used interchangeably.

[0069] Various methods are described herein, each of which includes one or more steps or acts for achieving the described method. Unless a specific order of steps or acts is required for proper operation of the method, the order and / or use of specific steps and / or acts may be modified or combined. Additionally, terms such as "first", "second", etc. may be used in various embodiments to modify elements, components, steps, operations, etc., such as, for example, "first decode" and "second decode". The use of such terms does not imply any ordering to the modified operations, unless specifically required. Thus, in this embodiment, the first decode need not be performed before the second decode, but may occur, for example, before, during, or during a period of overlap with the second decode.

[0070] Various methods and other aspects described herein may be used to modify modules, such as the decoding modules, of the video encoder 200 and decoder 300, as shown in Figures 2 and 3. Moreover, the subject matter disclosed herein may apply to any type, format, or version of video coding, whether described in a standard or recommendation, whether existing or developed in the future, and to extensions of any such standards and recommendations, for example. Unless otherwise indicated or technically impossible, aspects described herein may be used individually or in combination.

[0071] Various values ​​are used in the examples described in this application, such as the number of intra prediction modes, the number of most probable modes (MPMs), additional intra prediction modes, block size dimensions, ratio of block height to block width, block shapes, prediction mode indexes, wide angle intra prediction (WAIP) modes, angle degrees, angle mode ranges, etc. These specific values ​​and other values ​​are for purposes of illustrating the examples, and the described aspects are not limited to those specific values.

[0072] 2 illustrates an exemplary video encoder. Although variations of the exemplary encoder 200 are contemplated, the encoder 200 is described below for purposes of clarity without describing all possible variations.

[0073] Before encoding, a video sequence may undergo pre-encoding processing (201), such as applying a color transformation to the input color picture (e.g., converting from RGB 4:4:4 to YCbCr 4:2:0) or performing a remapping of the input picture components to obtain a signal distribution that is more resilient to compression (e.g., using histogram equalization of one of the color components). Metadata may be associated with that pre-processing and attached to the bitstream.

[0074] In the encoder 200, a picture is coded by the encoder elements, as described below. The picture to be coded is divided (202) and processed, for example, in coding units (CUs). Each unit is coded, for example, using either intra-mode or inter-mode. When a unit is coded in intra-mode, it performs intra prediction (260). In inter-mode, motion estimation (275) and motion compensation (270) are performed. The encoder decides (205) whether to use intra-mode or inter-mode to code the unit, and indicates the decision, for example, by a prediction mode flag. A prediction residual is calculated (210), for example, by subtracting the prediction block from the original image block.

[0075] The prediction residual is then transformed (225) and quantized (230). The quantized transform coefficients, as well as motion vectors and other syntax elements, such as picture partition information, are entropy coded (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 coded directly without applying a transform or quantization process.

[0076] The encoder decodes the coded block to provide a reference for further prediction. To decode the prediction residual, the quantized transform coefficients are dequantized (240) and inverse transformed (250). The decoded prediction residual and the predicted block are combined (255) to reconstruct an image block. An in-loop filter (265) is applied to the reconstructed picture to perform, for example, deblocking / Sample Adaptive Offset (SAO) / Adaptive Loop filter (ALF) filtering to reduce coding artifacts. The filtered image is stored in a reference picture buffer 280.

[0077] 3 illustrates an example of a video decoder. In the exemplary decoder 300, the bitstream is decoded by decoder elements as described below. The video decoder 300 generally performs a decoding path that is the inverse of the encoding path described in FIG. 2. Furthermore, the encoder 200 generally performs video decoding as part of the video data encoding.

[0078] In particular, the decoder input includes a video bitstream, which may be generated by the video encoder 200. First, the bitstream is entropy decoded (330) to obtain transform coefficients, prediction modes, motion vectors, and other coded information. Picture partition information indicates how the picture is partitioned. Thus, the decoder may partition the picture according to the decoded picture partition information (335). To decode the prediction residual, the transform coefficients are dequantized (340) and inverse transformed (350). The decoded prediction residual and the predicted block are combined (355) to reconstruct an image block. The predicted block may be obtained from intra prediction (360) or from motion-compensated prediction (i.e., inter 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). In some examples, for a given picture, the contents of the reference picture buffer 380 on the decoder 300 side may be identical to the contents of the reference picture buffer 280 on the encoder 200 side (eg, for the same picture).

[0079] The decoded picture may further undergo post-decoding processing (385), such as an inverse color conversion (e.g., from YCbCr 4:2:0 to RGB 4:4:4) or inverse remapping that performs the inverse of the remapping process performed in the pre-encoding processing (201). The post-decoding processing may use metadata derived in the pre-encoding processing and signaled in the bitstream. In an embodiment, the decoded image (e.g., after application of an in-loop filter (365) and / or after post-decoding processing (385), if post-decoding processing is used) may be sent to a display device for rendering to a user.

[0080] FIG. 4 illustrates an example of a system in which various aspects and embodiments described herein may be implemented. System 400 may be embodied as a device including various components described below and configured to implement one or more of the aspects described herein. Examples of such devices include various electronic devices, such as, but not limited to, personal computers, laptop computers, smartphones, tablet computers, digital multimedia set-top boxes, digital television receivers, personal video recording systems, connected appliances, and servers. The elements of system 400, singly or in combination, may be embodied in a single integrated circuit (IC), multiple ICs, and / or separate components. For example, in at least one embodiment, the processing and encoder / decoder elements of system 400 are distributed across multiple ICs and / or separate components. In various embodiments, system 400 is communicatively coupled to one or more other systems or other electronic devices, for example, via a communication bus or through dedicated input and / or output ports. In various embodiments, system 400 is configured to implement one or more of the aspects described herein.

[0081] The system 400 is configured to execute instructions loaded therein, for example to implement various aspects described herein. The system 400 includes at least one processor 410. The processor 410 can include embedded memory, input / output interfaces, and various other circuits known in the art. The system 400 includes at least one memory 420 (e.g., a volatile memory device and / or a non-volatile memory device). The system 400 includes a storage device 440, which can include non-volatile memory and / or volatile memory, including, but not limited to, Electrically Erasable Programmable Read-Only Memory (EEPROM), Read-Only Memory (ROM), Programmable Read-Only Memory (PROM), Random Access Memory (RAM), Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM), Flash, magnetic disk drive, and / or optical disk drive. Storage device(s) 440 may include, by way of non-limiting example, internal storage devices, attached storage devices (including removable and non-removable storage devices), and / or network-accessible storage devices.

[0082] The system 400 includes an encoder / decoder module 430 configured to process data to provide, for example, encoded or decoded video, and the encoder / decoder module 430 may include its own processor and memory. The encoder / decoder module 430 represents a module that may be included in a device to perform encoding and / or decoding functions. As is known, a device may include one or both of an encoding module and a decoding module. It is noted that the encoder / decoder module 430 may be implemented as a separate element of the system 400 or may be incorporated in the processor 410 as a combination of hardware and software known to those skilled in the art.

[0083] Program code to be loaded into the processor 410 or the encoder / decoder 430 to implement various aspects described herein may be stored in the storage device 440 and then loaded into the memory 420 for execution by the processor 410. According to various embodiments, one or more of the processor 410, the memory 420, the storage device 440, and the encoder / decoder module 430 may store one or more of various items during performance of the processes described herein. Such stored items may include, but are not limited to, input video, decoded video or portions of decoded video, bitstreams, matrices, variables, and intermediate or final results from the processing of equations, expressions, operations, and computational logic.

[0084] In some embodiments, memory internal to the processor 410 and / or the encoder / decoder module 430 is used to store instructions and provide working memory for processing required during encoding or decoding. However, in other embodiments, memory external to the processing device (e.g., the processing device can be either the processor 410 or the encoder / decoder module 430) is used for one or more of these functions. The external memory may be the memory 420 and / or the storage device 440, e.g., dynamic volatile memory and / or non-volatile flash memory. In some embodiments, an external non-volatile flash memory is used, e.g., to store the television's operating system. In at least one embodiment, a high-speed external dynamic volatile memory, such as a RAM, is used as working memory for video encoding and decoding operations.

[0085] Inputs to the elements of system 400 may be provided through various input devices, as shown in block 445. Such input devices may include, but are not limited to, (i) a radio frequency (RF) section that receives, for example, RF signals transmitted over the air by a broadcast station, (ii) a component (COMP) input terminal (or set of COMP input terminals), (iii) a universal serial bus (USB) input terminal, and / or (iv) a High Definition Multimedia Interface (HDMI) input terminal. Other examples include composite video, not shown in FIG. 4.

[0086] In various embodiments, the input devices of block 445 have associated respective input processing elements as known in the art. For example, the RF section may be associated with elements suitable for (i) selecting a desired frequency (also referred to as selecting a signal or band-limiting a signal to a band of frequencies), (ii) down-converting the selected signal, (iii) band-limiting again to a narrower frequency band to select a signal frequency band, which in certain embodiments may be referred to as a channel (for example), (iv) demodulating the down-converted band-limited signal, (v) performing error correction, and / or (vi) demultiplexing to select a desired data packet stream. The RF section of various embodiments includes one or more elements for performing these functions, such as a frequency selector, a signal selector, a band limiter, a channel selector, a filter, a down-converter, a demodulator, an error corrector, and a demultiplexer. The RF section may include a tuner to perform various of these functions, including, for example, down-converting a received signal to a lower frequency (e.g., an intermediate frequency or a near-baseband frequency) or to baseband. In one set-top box embodiment, the RF section and its associated input processing elements receive RF signals transmitted over a wired (e.g., cable) medium and perform frequency selection by filtering, down-converting, and filtering again to a desired frequency band. Various embodiments rearrange the order of the above-described (and other) elements, remove some of these elements, and / or add other elements to perform similar or different functions. Adding elements can include inserting elements between existing elements, such as, for example, inserting amplifiers and analog-to-digital converters. In various embodiments, the RF section includes an antenna.

[0087] The USB and / or HDMI terminals may include respective interface processors for connecting the system 400 to other electronic devices via USB and / or HDMI connections. It should be appreciated that various aspects of the input processing, e.g., Reed-Solomon error correction, may be implemented, for example, in a separate input processing IC or in the processor 410, as desired. Similarly, aspects of the USB or HDMI interface processing may be implemented, for example, in a separate interface IC or in the processor 410, as desired. The demodulated, error corrected, and demultiplexed streams are provided to various processing elements, including, for example, the processor 410 and an encoder / decoder 430 operating in combination with memory and storage elements, to process the data streams necessary for presentation to an output device.

[0088] The various elements of system 400 may be provided within an integrated housing in which the various elements may be interconnected and transmit data between them using a suitable connection arrangement 425, such as an internal bus known in the art, including an Inter-IC (I2C) bus, hardwired, and printed circuit boards.

[0089] System 400 includes a communication interface 450 that enables communication with other devices over a communication channel 460. Communication interface 450 may include, but is not limited to, a transceiver configured to transmit and receive data over communication channel 460. Communication interface 450 may include, but is not limited to, a modem or a network card, and communication channel 460 may be implemented in a wired and / or wireless medium, for example.

[0090] Data is streamed or otherwise provided to system 400 in various embodiments using a wireless network such as a Wi-Fi network, e.g., IEEE 802.11 (IEEE refers to the Institute of Electrical and Electronics Engineers). The Wi-Fi signal in these embodiments is received via communication channel 460 and communication interface 450 adapted for Wi-Fi communication. Communication channel 460 in these embodiments is typically connected to an access point or router that provides access to external networks, including the Internet, to enable streaming applications and other over-the-top communications. Other embodiments provide streamed data to system 400 using a set-top box that delivers data via an HDMI connection in input block 445. Still other embodiments provide streamed data to system 400 using an RF connection in input block 445. As noted above, various embodiments provide data in a non-streaming manner. Additionally, various embodiments use wireless networks other than Wi-Fi, e.g., cellular networks or Bluetooth networks.

[0091] System 400 can provide output signals to various output devices, including a display 475, speakers 485, and other peripheral devices 495. Display 475 in various embodiments includes one or more of a touch screen display, an organic light emitting diode (OLED) display, a curved display, and / or a foldable display, for example. Display 475 can be for a television, a tablet, a laptop, a mobile phone, or other device. Furthermore, display 475 can be integrated with other components (e.g., as in a smart phone) or can be separate (e.g., an external monitor for a laptop). Other peripheral devices 495 in various embodiments include one or more of a stand-alone digital video disc (or digital versatile disc) (DVD for both terms), a disc player, a stereo system, and / or a lighting system. Various embodiments 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.

[0092] In various embodiments, control signals are communicated between system 400 and display 475, speaker 485, or other peripheral devices 495 using signaling such as AV.Link, Consumer Electronics Control (CEC), or other communication protocols that allow control between devices with or without user intervention. Output devices may be communicatively coupled to system 400 via dedicated connections through respective interfaces 470, 480, and 490. Alternatively, output devices may be connected to system 400 via communication interface 450 using communication channel 460. Display 475 and speaker 485 may be integrated into a single unit with other components of system 400 in an electronic device such as, for example, a television. In various embodiments, display interface 470 includes a display driver, such as, for example, a timing controller (TCon) chip.

[0093] Display 475 and speakers 485 may alternatively be separate from one or more of the other components, for example, if the RF portion of input 445 is part of a separate set-top box. In various embodiments in which display 475 and speakers 485 are external components, output signals may be provided via dedicated output connections including, for example, an HDMI port, a USB port, or a COMP output.

[0094] These embodiments may be performed by the processor 410, or by computer software implemented by hardware, or by a combination of hardware and software. As a non-limiting example, these embodiments may be implemented by one or more integrated circuits. The memory 420 may be of any type suitable for the technology environment, and may be implemented using any suitable data storage technology, such as, as non-limiting examples, optical memory devices, magnetic memory devices, semiconductor-based memory devices, fixed memories, and removable memories. The processor 410 may be of any type suitable for the technology environment, and may include, as non-limiting examples, one or more of a microprocessor, a general-purpose computer, a special-purpose computer, and a processor based on a multi-core architecture.

[0095] Various implementations involve decoding. As used herein, "decoding" may encompass all or part of the processes performed on a received encoded sequence to provide a final output suitable for, for example, a display. In various embodiments, such processes include processes typically performed by a decoder, such as one or more of entropy decoding, inverse quantization, inverse transform, and differential decoding. In various embodiments, such processes may also or alternatively include processes performed by a decoder in various implementations described herein, such as obtaining a Most Probable Mode (MPM) list associated with the current block, determining a test list of intra-prediction modes from the MPM list, testing a first intra-prediction mode that is excluded from the test list or not allowed to be tested due to a wide-angle intra-prediction (WAIP) permutation, generating a prediction for the current block based on the tested intra-prediction mode, and decoding the current block using the prediction.

[0096] As a further example, in one embodiment, "decoding" refers to entropy decoding only, in another embodiment, "decoding" refers to differential decoding only, and in another embodiment, "decoding" refers to a combination of entropy decoding and differential decoding. Whether the phrase "decoding process" is intended to refer specifically to a subset of operations or to the broader decoding process as a whole will be clear based on the context of the specific description and will be well understood by one of ordinary skill in the art.

[0097] Various implementations involve encoding. Similar to the above discussion regarding "decoding," "encoding" as used herein can encompass, for example, all or part of the processes performed on an input video sequence to produce an encoded bitstream. In various embodiments, such processes include one or more of processes typically performed by an encoder, such as partitioning, differential encoding, transforming, quantizing, and entropy encoding. In various embodiments, such processes may also or alternatively include, for example, processes performed by an encoder in various implementations described herein, namely, obtaining a Most Probable Mode (MPM) list associated with the current block, determining a test list of intra-prediction modes from the MPM list, testing a first intra-prediction mode that is excluded from the test list or not allowed to be tested due to a wide-angle intra-prediction (WAIP) permutation, generating a prediction for the current block based on the tested intra-prediction mode, and encoding the current block using the prediction.

[0098] As a further example, in one embodiment, "encoding" refers to only entropy encoding, while in another embodiment, "encoding" refers to only differential encoding, while in another embodiment, "encoding" refers to a combination of differential and entropy encoding. Whether the phrase "encoding process" is intended to refer specifically to a subset of operations or to the broader encoding process as a whole will be clear based on the context of the specific description and will be well understood by one of ordinary skill in the art.

[0099] It should be noted that the coding syntax for syntax elements used herein, e.g., precision factor, shift, number of fractional bits, intra-prediction mode, index, range, dimension, weight, flag, calculation, shape, etc., are descriptive terms and therefore do not preclude the use of other syntax element names.

[0100] Where a figure is presented as a flow diagram, it should be understood that the figure also provides a block diagram of the corresponding apparatus. Similarly, where a figure is presented as a block diagram, it should be understood that the figure also provides a flow diagram of the corresponding method / process.

[0101] The implementations and aspects described herein may be implemented, for example, in a method or process, an apparatus, a software program, a data stream, or a signal. Even if discussed in the context of only a single implementation form (e.g., discussed only as a method), the implementation of the discussed features may also be implemented in other forms (e.g., an apparatus or a program). An apparatus may be implemented, for example, in appropriate hardware, software, and firmware. A method may be implemented, for example, in a processor, which generally refers to a processing device and includes, for example, a computer, a microprocessor, an integrated circuit, or a programmable logic device. Processors also include communication devices, such as, for example, computers, cellular phones, portable / personal digital assistants ("PDAs"), and other devices that facilitate communication of information between end users.

[0102] References to "one example" or "an example" or "one implementation" or "an implementation," as well as other variations thereof, mean that a particular feature, structure, characteristic, etc. described in connection with an embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one example" or "in an example" or "in one implementation" or "in an implementation" in various places throughout this application, as well as any other variations, are not necessarily all referring to the same embodiment.

[0103] Additionally, the application may refer to "determining" various information. Determining information may include, for example, one or more of estimating information, calculating information, predicting information, or retrieving information from a memory. Obtaining may include receiving, retrieving, constructing, generating, and / or determining.

[0104] Additionally, the application may refer to "accessing" various information. Accessing information may include, for example, one or more of receiving information, retrieving information (e.g., from a memory), storing information, moving information, copying information, calculating information, determining information, predicting information, or estimating information.

[0105] Additionally, the application may refer to "receiving" various information. Receiving, like "accessing," is intended to be a broad term. Receiving information may include, for example, one or more of accessing information or retrieving information (e.g., from a memory). Furthermore, "receiving" generally involves in some manner an operation, such as, for example, storing information, processing information, transmitting information, moving information, copying information, erasing information, calculating information, determining information, predicting information, or estimating information.

[0106] For example, in the case of "A / B," "A and / or B," and "at least one of A and B," it should be understood that the use of any of the following " / ," "and / or," and "at least one of" is intended to encompass the selection of only the first enumerated alternative (A), or the selection of only the second enumerated alternative (B), or the selection of both alternatives (A and B). As a further example, in the case of "A, B, and / or C" and "at least one of A, B, and C," such language is intended to encompass the selection of only the first enumerated alternative (A), or the selection of only the second enumerated alternative (B), or the selection of only the third enumerated alternative (C), or the selection of only the first and second enumerated alternatives (A and B), or the selection of only the first and third enumerated alternatives (A and C), or the selection of only the second and third enumerated alternatives (B and C), or the selection of all three alternatives (A and B and C). This can be expanded as many times as the items listed, as would be apparent to one of ordinary skill in this and related arts.

[0107] Also, as used herein, the term "signaling" specifically means to indicate something to a corresponding decoder. The encoder signal may include, for example, an intra-prediction mode index (e.g., via MPM list-based signaling), etc. In this way, in one embodiment, the same parameters are used at both the encoder and decoder sides. Thus, for example, the encoder may transmit a specific parameter to the decoder so that the decoder can use the same specific parameter (explicit signaling). Conversely, if the decoder already has the specific parameter as well as other parameters, it may use signaling without transmitting, simply to allow the decoder to know and select the specific parameter (implicit signaling). By avoiding the transmission of any actual functionality, bit savings are realized in various embodiments. It should be understood that signaling may be achieved in various ways. For example, in various embodiments, one or more syntax elements, flags, etc. are used to signal information to a corresponding decoder. Although the above relates to the verb form of the term "signal", the term "signal" may also be used as a noun in this specification.

[0108] As will be apparent to one of ordinary skill in the art, implementations may generate a variety of signals formatted to carry information that may be, for example, stored or transmitted. Information may include, for example, instructions for performing a method or data generated by one of the described implementations. For example, a signal may be formatted to carry a bit stream of the described embodiments. Such a signal may be formatted, for example, as an electromagnetic wave (e.g., using a radio frequency portion of the spectrum) or as a baseband signal. Formatting may include, for example, encoding a data stream and modulating a carrier wave with the encoded data stream. The information that the signal carries may be, for example, analog information or digital information. The signal may be transmitted by a variety of different wired or wireless links, as is well known. The signal may be stored in, accessed from, or received from a processor-readable medium.

[0109] Many examples are described herein. Features of the examples may be provided alone or in any combination across various claim categories and types. Furthermore, examples may include one or more of the features, devices, or aspects described herein, alone or in any combination across various claim categories and types. For example, features described herein may be embodied in a bitstream or signal that includes information generated as described herein. The information may enable 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 generating and / or transmitting and / or receiving and / or decoding a bitstream or signal. For example, features described herein may be implemented as a method, process, apparatus, medium storing instructions, medium storing data, or signal. For example, features described herein may be implemented by a TV, a set-top box, a mobile phone, a tablet, or other electronic device that performs decoding. A TV, set-top box, mobile phone, tablet, or other electronic device may display (e.g., using a monitor, screen, or other type of display) the resulting image (e.g., an image from the residual reconstruction of the video bitstream). A TV, set-top box, mobile phone, tablet, or other electronic device may receive a signal that includes the encoded image and perform decoding.

[0110] Intra prediction is a coding tool in video coding (e.g., hybrid video coding). Intra prediction may be used to make a prediction for a block. An encoder may select a (e.g., best) intra prediction mode, e.g., in terms of rate distortion. The encoder may signal an index (e.g., an index associated with the selected intra prediction mode) to a decoder. The decoder may use the signaled index to perform the same prediction for (e.g., each) block performed by the encoder. Signaling the index of the selected intra prediction mode may add extra overhead and reduce the gain from intra prediction. The index of the intra prediction mode selected to predict a given block may be coded to create a set of most probable modes (MPMs), which may reduce signaling overhead, e.g., if the index of the selected intra prediction mode belongs to a list. Signaling the coded intra prediction mode index to create a set of MPMs may be referred to as MPM list-based signaling. For example, video coding using VVC and / or HEVC may be implemented with MPM list-based signaling. In other video coding implementations (e.g., ECM), multiple (e.g., two) MPM lists (e.g., instead of one MPM list) may be implemented. Herein, signaling of mode indexes, such as MPM list-based signaling, may be referred to as signaling of modes.

[0111] The signaling overhead may be limited (e.g., by ECM) using (e.g., additionally and / or alternatively) one or more tools based on (e.g., derived from) decoded pixels surrounding a given block (e.g., in an intra-prediction mode) that may be used to predict a block (e.g., in terms of rate-distortion) (e.g., likely to be best). The first video coding tool may be a Decoder-side Intra Mode Derivation (DIMD). The second video coding tool may be a Template-based Intra Mode Derivation (TIMD). The signaling overhead may be reduced, for example, using the first and / or second tools. Signaling the tools may enable the decoder to obtain an index of the (e.g., likely to be best) intra-prediction mode. In an embodiment (e.g., using DIMD), a template of the decoded pixels above and / or to the left of the current block may be analyzed to infer the template's directionality, from which one or more (e.g., two) directional intra-prediction modes may be selected. A prediction signal may be generated, for example, by blending multiple (e.g., two) modes with a planar mode. In an embodiment (e.g., using TIMD), several intra-prediction modes may be tested against the template of the decoded pixels above and / or to the left of the current block. One or more (e.g., two) modes that result in the smallest Sum of Absolute Transform Differences (SATD) between the template of the decoded pixel and the mode prediction of the template may be selected (e.g., kept or maintained). A prediction signal may be generated, for example, by applying the mode with the smallest SATD or blending multiple (e.g., two) modes.

[0112] In an embodiment (e.g., VVC and / or ECM for non-square blocks), one or more (e.g., some) directional intra-prediction modes may be replaced with one or more other intra-prediction modes to obtain (e.g., maximum) information from decoded reference samples around the current block while maintaining the same number of intra-mode predictions, e.g., without increasing signaling overhead. TIMD can bypass the signaling overhead. The replacement of intra-prediction modes for TIMD may be adapted for rate-distortion efficiency.

[0113] Intra-prediction mode signaling may be provided in various video coding tools (e.g., ECM) and TIMD. In an embodiment, 67 intra-prediction modes may be provided as core intra-prediction modes. Any edge direction presented in a video (e.g., natural video) may be captured by a directional intra-prediction mode. Additional directional intra-prediction modes may be provided in one video coding method, for example, 33 used in one video coding method (e.g., in HEVC) versus 65 used in a second video coding method (e.g., in VVC), or another number.

[0114] Figure 5 illustrates an example of intra-prediction modes in a video coding implementation (e.g., VVC and ECM). Directional intra-prediction modes are illustrated as solid and dotted arrows in Figure 5 to indicate various densities of intra-prediction modes. For example, the solid lines in Figure 5 may illustrate 33 intra-prediction modes for HEVC, and a combination of the solid and dotted lines in Figure 5 may indicate 65 intra-prediction modes in VVC. Directional intra-prediction modes may be applied to one or more (e.g., all) block sizes and / or for luma and / or chrominance intra-prediction.

[0115] Planar mode and DC mode may be similar in HEVC and VVC. In HEVC, an intra-coded block (e.g., each) may have a square shape. The length of each side of the square may be a power of two. A division operation (e.g., in DC mode) may not be implemented to generate an intra predictor. A block may have a rectangular shape (e.g., in VVC). A division operation may be implemented per block (e.g., for rectangular shapes). The longer side may be used, for example, to calculate the average of a non-square block to avoid a division operation (e.g., for prediction in DC mode).

[0116] In an embodiment (e.g., in ECM), there may be 67 intra prediction modes. Directional intra prediction modes may include 4-tap or 6-tap interpolation. Directional intra prediction modes may include Position Dependent Intra Prediction Combination (PDPC), which may be complemented with a gradient PDPC.

[0117] Intra prediction mode signaling may be implemented, for example, in an ECM. Intra prediction mode signaling may include signaling in luminance. If the intra prediction mode selected to predict the current luminance CB is not DIMD, not a Matrix-based Intra Prediction (MIP) mode, not TIMD, and / or one of the 67 intra prediction modes (e.g., as described herein), an index may be signaled, for example, using an MPM list of coding blocks (CB) (e.g., in an ECM). One or more tools, such as Block Differential Pulse Coded Modulation (BDPCM), Template-based Intra Prediction (TMP), Intra Block Copy (IBC), and / or palette, may be ignored, for example, if one or more tools are activated (e.g., exclusively) for one or more (e.g., specific) video sequences (e.g., screen content). An MPM list (e.g., in an ECM) may be decomposed into a list of one or more (e.g., six) primary MPMs and a list of one or more (e.g., 22) secondary MPMs, as shown by example in Figures 6A and 6B. The MPM list may be constructed (e.g., sequentially constructed) by adding candidate intra-prediction mode indexes. The MPM list may be ordered from the candidate intra-prediction mode index that is most likely to be the selected intra-prediction mode for predicting the current luminance CB to the candidate intra-prediction mode index that is least likely to be selected as the intra-prediction mode for predicting the current luminance CB.

[0118] 6A and 6B illustrate an exemplary derivation of an MPM list for a current luminance CB belonging to an intra slice (eg, as implemented in ECM).

[0119] 6A and 6B show (e.g., from left to right) the addition of candidate intra-prediction mode indexes (e.g., sequentially) when, for example, the current luminance CB belongs to an intra slice. Redundancy may not exist in the list of the MPM, for example, there may not be identical intra-prediction mode indexes. FIG. 6A and 6B illustrate an example in which each candidate intra-prediction mode index is different from each other. In an example, the slots of indexes 0 to i-1 included in the list of the MPM may already be filled. A candidate may be skipped, for example, if the current candidate intra-prediction mode index is already present in the current list of the MPM, and the next candidate intra-prediction mode may be inserted, for example, in the slot of index i if it is not present in the list of the MPM. The current intra-prediction mode index may be inserted, for example, in the slot of index i if the current intra-prediction mode index is not present in the list of the MPM, and the next candidate intra-prediction mode index may be inserted, for example, in the slot of index i+1 if the next candidate intra-prediction mode index is not present in the list of the MPM.

[0120] Figures 7A and 7B illustrate an example of signaling an intra-prediction mode selected to predict a current luminance CB in an ECM. The example shown in Figures 7A and 7B describes signaling an intra-prediction mode selected to predict a current luminance CB at the encoder side. This example may be applicable to the decoder side. Figure 7A shows a Multiple Reference Line (MRL). As shown in Figure 7A, the MRL index may belong to {0,1,3}, for example, when the TIMD flag is equal to 1. An MRL index equal to 0 may indicate that the MRL is not used to predict the current luminance CB. An MRL index equal to 1 may indicate that the second row of decoded reference samples above the current luminance CB and the second column of decoded reference samples to the left of the current luminance CB are used for prediction. An MRL index equal to 3 may indicate that the fourth row of decoded reference samples above the current luminance CB and the fourth column of decoded reference samples to the left of the current luminance CB are used for prediction. As shown in FIG. 7A, the MRL index may belong to {0, 1, 3, 5, 7, 12}, for example, when the TIMD flag is equal to 0. FIG. 7A shows an Intra Sub-Partition (ISP). As shown in FIG. 7A, the ISP mode index may belong to {0, 1, 2}. An ISP index equal to 0 may indicate that ISP is not used for the current luminance CB. An ISP mode index equal to 1 may indicate that the current luminance CB is divided horizontally into luminance transform blocks (TBs). An ISP mode index equal to 2 may indicate that the current luminance CB is divided vertically into luminance TBs. In the examples shown in FIGS. 7A and 7B, one or more tools, such as BDPCM, TMP, IBC, and / or palette, may be omitted, for example, if the tools are turned on for one or more video sequences.

[0121] An intra-prediction mode may be signaled to predict chrominance. FIG. 8 illustrates an example of signaling an intra-prediction mode selected to predict a current pair of chrominance CBs (e.g., as implemented in ECM). FIG. 8 illustrates an example of signaling an intra-prediction mode selected to predict a current pair of chrominance CBs (e.g., co-located Cb and Cr CBs). As shown by the example of FIG. 8, multiple (e.g., four) possibilities for the current intra-prediction mode index may include, for example, an index of a planar mode, an index of a horizontal mode, an index of a vertical mode, and an index of DC if a Direct Mode (DM) flag is equal to 1. Redundancy in a set of modes (e.g., four) may be avoided, for example, when one of the set of modes is DM. In such an example, the index of the redundant mode may be replaced by an index of a vertical diagonal mode. A Cross-Component Linear Model (CCLM) may include multiple (e.g., six) different intra-prediction modes, such as LM, MMLM, MDLM_L, MDLM_T, MMLM_L, and MMLM_T, in ECM, etc. A CCLM may include multiple (e.g., three) different intra-prediction modes, such as VVC, etc.

[0122] Wide-angle intra prediction (WAIP) may be implemented. One or more (e.g., some) angular intra prediction modes may be supplemented or replaced with wide-angle modes, such as those implemented for non-square blocks in VVC and / or ECM. The replaced modes may be signaled (e.g., using a primitive method) and remapped (e.g., after parsing) to the index of the wide-angle mode. In an example, the total number of (e.g., core) intra prediction modes may remain unchanged (e.g., 67).

[0123] Figures 9A and 9B illustrate an example of a set of decoded reference samples for a current WxH block to be predicted, including an array of top decoded reference samples having a length equal to 2W + 1 and an array of left decoded reference samples having a length equal to 2H + 1. Figures 9A and 9B show the relationship between the range of the set of decoded reference samples around the current WxH block and the range of allowed intra-prediction angles.

[0124] Table 1 presents an example of indexes for intra prediction modes that are replaced by wide-angle modes in VVC and ECM, for example, depending on the size of the current block to be predicted.

[0125] 9A-9B illustrate an example relationship between the range of a set of decoded reference samples around (eg, surrounding) a current WxH block to be predicted and the range of allowed intra-prediction angles.

[0126] [Table 1]

[0127] FIG. 10 illustrates an example of how angular intra modes may be replaced by wide-angle modes for non-square blocks with widths (e.g., strictly) greater than heights. As shown by the example of FIG. 10, mode 2 may be replaced by wide-angle mode 67. Mode 3 may be replaced by wide-angle mode 68. For example, the current block to predict may be 8×4. The process of replacement may continue (e.g., gradually) until mode 7 is replaced by wide-angle mode 72.

[0128] Template-based intra mode derivation (TIMD) may be implemented. Intra prediction mode derivation via TIMD may be applied (e.g., in the same manner) at the encoder side and the decoder side for a given luminance, such as CB (103) shown in FIG. 11A. (e.g., each) intra prediction mode in the MPM list of luminance CB (e.g., complemented with a default mode) may calculate (e.g., as needed) a prediction of the template (1100 and 1101) of luminance CB from the decoded reference sample of the template (1102). The SATD between the prediction and the template of luminance CB may be calculated. The intra prediction modes (e.g., two) with the smallest (e.g., smallest) SATD may be selected as the TIMD mode. The set of directional intra prediction modes (e.g., for TIMD) may be expanded (e.g., from 65 to 129), for example, by inserting a direction between each solid line and the adjacent dotted line in FIG. 5. The set of possible intra-prediction modes derived via the TIMD may collect 131 modes. One or more (e.g., two) intra-prediction modes may be retained from the first pass of testing with the MPM list and may be supplemented with a default mode. The TIMD may test the closest (e.g., two) extended directional intra-prediction modes (e.g., with respect to the predicted SATD) (for each retained intra-prediction mode that is not PLANAR or DC). In an example, it may be assumed that the template of luminance CB does not fall outside the boundaries of the current frame. Figures 11B and 11C show an example in which at least a portion (e.g., a portion) of the template of luminance CB falls outside the boundaries of the current frame.

[0129] The current luminance CB may be predicted via TIMD, for example, by fusing (e.g., two) predictions of luminance CB via (e.g., two) TIMD modes resulting from (e.g., two) passes of testing with weights (e.g., after applying PDPC). The weights (e.g., calculated weights) used may depend on the prediction SATD of the (e.g., two) TIMD modes. In an example, the generated prediction may be based on the calculated weights. The calculated weights may include a first calculated weight associated with the first intra-prediction mode tested and a second weight associated with the second intra-prediction mode tested.

[0130] 11A-11C illustrate examples of a template of a current luminance CB and a decoded reference sample of the template. t ×H is the left W×H part (1100) and W×h t The example shows that the part (1101) above the current luminance CB (1103) is surrounded by the fully available template including W×H. The intra prediction modes tested are the decoded reference samples (1102) of the template (e.g., during the TIMD derivation step) 1+2w t +2W+2h t +2H can predict the template of the current luminance CB. In one example (e.g., ECM), if W≦8, then w t is equal to 2, otherwise w t is equal to 4. In one example, if H≦8, then h t is equal to 2, otherwise h t is equal to 4. Figure 11B shows the current luminance CB(1103)W×h t But available W×h t The example shows a region (1101) above the current luminance CB (1103) surrounded by a template with W×H. The intra prediction modes tested are the decoded reference samples (1102) of the template (e.g., during the TIMD derivation step) 1+2W+2h tFrom +2H, the template of the current luminance CB can be predicted. FIG. 11C shows the current luminance CB (1103) w t x H is the available W x h t The left part (1100) shows an example surrounded by a template with W×H. The intra prediction modes tested are the decoded reference samples (1102) of the template (e.g., during the TIMD derivation step) 1+2w t From +2W+2H the template of the current luminance CB can be predicted.

[0131] The set of directional intra-prediction modes may be extended, for example, from 65 to 129 for TIMD. Intra-prediction mode substitution in WAIP may be adapted, for example, as shown in Table 2. For example, a given 8×4 luminance CB may use TIMD. Mode 2 may be replaced with wide-angle mode 131, mode 3 may be replaced with wide-angle mode 132, mode 4 may be replaced with wide-angle mode 133, ..., mode 12 may be replaced with wide-angle mode 141, etc. Multiple indices of intra-prediction modes may be generated, and the multiple indices of intra-prediction modes may be used to generate a prediction for the current block. Weights of the multiple indices of intra-prediction modes may be calculated. One of the weights may be the sum of absolute transform differences (SATD), and a prediction for the current block may be generated based on a subset of the index of the intra-prediction mode with the smallest predicted SATD from the multiple indices of intra-prediction modes.

[0132] [Table 2]

[0133] Template-based intra mode derivation (TIMD) may be implemented. TIMD may be implemented with an extended WAIP. A tested intra prediction mode may be selected from the MPM list of the current luminance CB during the TIMD derivation process. The selected intra prediction mode may be supplemented with a default mode. The selected mode may be subject to WAIP substitution (e.g., as described herein) (e.g., as needed). The tested intra prediction mode may not be removed by the wide-angle process, for example, when TIMD is applied to a non-square luminance CB.

[0134] The efficiency of TIMD may be improved, for example, by making one or more (e.g., all) intra-prediction modes (e.g., wide or not wide) available for TIMD. In examples (e.g., implementations), the number of modes tested may be suppressed to reduce the complexity of the search for the best TIMD candidate. Examples (e.g., all examples) may be implemented without extra signaling, regardless of the mode chosen.

[0135] A directional intra prediction mode replaced by WAIP for a rectangular CU may be allowed. In an example (e.g., as shown in FIG. 12A-FIG. 12B), a replaced intra prediction mode (e.g., due to a wide-angle process when performing TIMD on a rectangular CU) may be allowed.

[0136] 12A-12B illustrate an example of a range of directions added by WAIP and a range of directions replaced by WAIP. A range of directions replaced by WAIP may be allowed.

[0137] In one example (e.g., based on Table 2), a range of intra-prediction mode indices [|2,28|] may be allowed for the current 16×4 luminance CB using TIMD. A range of intra-prediction mode indices (e.g., [|131, 157|]) generated by the WAIP process may be allowed (e.g., similarly). In another example (e.g., another), a range of intra-prediction mode indices [|2,30|] may be allowed for the current 32×4 luminance CB using TIMD. A range of intra-prediction mode indices (e.g., [|131, 159|]) resulting from the WAIP process may be allowed (e.g., similarly). In an example, the span of directional intra-prediction modes in TIMD may be used in the ECM. The example (e.g., as described herein) may be extended to a (e.g., any) span of directional space for intra-prediction modes. In an example (e.g., as described herein), an implementation (e.g., using TIMD) may accommodate a density of directional intra-prediction modes that is four times greater than the density shown by the example of FIG. 5, which may be implemented, for example, by adding three directions between each solid line and the adjacent dotted line in FIG. 5.

[0138] Intra prediction modes allowed for CUs of similar shape may be allowed for CUs of other sizes. Modes that would be allowed for other CUs with similar shapes may be allowed when performing TIMD for CUs of a certain size, for example.

[0139] For example, TIMD may be performed for square CUs. For example, wide angles may be allowed for CUs with 1 / 2 or 2 / 1 width / height ratios in addition to other intra prediction modes (e.g., without limiting TIMD search). For example, TIMD may be performed for CUs with 2 / 1 (e.g., or 1 / 2) width / height ratios. Modes allowed in TIMD may include modes that may be allowed for CUs with 4 / 1 or 1 / 1 (e.g., or 1 / 4 or 1 / 1) width / height ratios.

[0140] In one example, the current 4×4 luminance CB may use TIMD. As described herein, the wide angles that would be allowed for 8×4 luminance CB and / or 4×8 luminance CB may be allowed for 4×4 luminance CB (e.g., in addition). For example, the TIMD applied to the 4×4 luminance CB may use 10 modes in the added range of the right part of Figures 12A and 12B and 10 modes in the added range of the left part of Figures 12A and 12B (e.g., in addition to the intra-prediction modes allowed for 4×4 luminance CB).

[0141] FIG. 13 illustrates an example of a range of directions added by WAIP and a range of directions replaced by WAIP when the reference sample for the current block is a square. The current block may be associated with a first shape, and the first intra-prediction mode (e.g., a mode excluded from the test list or not allowed to be tested due to WAIP replacement) may be associated with a second shape. The second shape may be associated with a direction replaced by WAIP. For example, for a rectangular block, before replacing the mode, the mode may be rectangular. In WAIP replacement, for example, the replaced mode may correspond to a shape (e.g., a shape that is a square). In FIG. 13, for example, mode 2 is 45 degrees, which may follow the characteristic of using a square block. The first shape may be a square, and the second shape may be a rectangle. Adjacent sides of the second shape may have different lengths from each other. FIG. 13 illustrates that an intra-prediction mode (e.g., a potential intra-prediction mode) may be used for the current block using TIMD. WAIP modes reserved for adjacent block sizes (e.g., W / H=2 (modes 131-141) and W / H=0.5 (modes 1-9)) may be allowed or included in the TIMD search for the current block, e.g., when W / H=4 and W / H=0.25, etc.

[0142] FIG. 14 illustrates an example of the range of directions added by WAIP and the range of directions replaced by WAIP when the reference sample for the current block is a rectangle. The current block may be associated with a first shape, and the first intra prediction mode (e.g., a mode that is excluded from the test list or not allowed to be tested due to WAIP replacement) may be associated with a second shape. The second shape may be associated with the direction replaced by WAIP. For example, for a square block, the mode may be square before replacing the mode. In WAIP replacement, for example, the replaced mode may correspond to a shape (e.g., a shape that is a rectangle). In FIG. 13, for example, mode 13 is 45 degrees and may follow the characteristic of using a rectangular block. The first shape may be a rectangle, and the second shape may be a square. Adjacent sides of the first shape may have different lengths from each other. In FIG. 13 and FIG. 14, for example, WAIP may use a wide angle that will be allowed for a CU (e.g., another CU) without restricting the TIMD search. WAIP modes reserved for adjacent block sizes (e.g., W / H=1 (2 to 12) and W / H=4 (142 to 149)) may be allowed in the TIMD search for the current block, e.g., when W / H=0.5 and W / H=8.

[0143] Tests for directional intra-prediction modes allowed during TIMD derivation may be added. As described herein with various examples, intra-prediction modes may be additionally allowed for TIMD. Tests for additional intra-prediction modes may be added to the TIMD derivation. FIG. 15 illustrates an example workflow for TIMD derivation for a current block to be predicted. As shown in FIG. 15, the position or implementation order of the additional group of tests within the workflow of TIMD derivation may vary. For example, as shown by the example of FIG. 16,

[0144]

number

[0145] 15 illustrates an example of TIMD derivation for a current block to be predicted, e.g., when one or more additional directional intra-prediction modes are allowed, e.g., as described herein. The example TIMD derivation procedure shown in FIG. 15 illustrates TIMD derivation in ECM and testing for additional allowed directional intra-prediction modes. As shown in FIG. 15,

[0146]

number

[0147] As shown in FIG. 15, 1502 to 1512 may include steps related to the derivation step of the TIMD procedure, and 1514 may be associated with the prediction step of the TIMD procedure. At 1502, an MPM list for the current block may be collected. At 1504, a test list of intra prediction modes may be constructed. A selected candidate intra prediction mode may be tested from the MPM list. Default modes (e.g., DC, horizontal, and / or vertical) may be included. At 1506, a mode (e.g., several modes) in the test list may be tested, and a WAIP permutation may be applied for the test (e.g., each test). At 1508, additional modes that are suppressed by the WAIP permutation and / or disallowed due to the size of the current block (e.g., disallowed in the test list) may be tested. At 1510, extended (e.g., several extended) direction intra prediction modes near i0 and i1 may be tested. At 1512, weights w0, w1 associated with the intra prediction mode may be calculated for blending. At 1514, as part of the prediction, the current block may be predicted via the mode of index i0 or by blending two predictions from the modes of indexes w0, w1 with weights i0, i1.

[0148] As shown in FIG. 16, 1602 to 1612 may include steps related to the derivation step of the TIMD procedure, and 1614 may be associated with the prediction step of the TIMD procedure. FIG. 16 illustrates an example of a TIMD derivation procedure for a current block to be predicted, for example, when / if one or more additional directional intra-prediction modes are allowed, for example, as described herein. At 1602, an MPM list for the current block may be collected. At 1604, a test list of intra-prediction modes may be constructed. A selected candidate intra-prediction mode may be tested from the MPM list. Default modes (e.g., DC, horizontal, and / or vertical) may be included. At 1606, a mode (e.g., several modes) in the test list may be tested, and a WAIP permutation may be applied for the test (e.g., each test). At 1608, extended (e.g., several extended) directional intra-prediction modes near i0 and i1 may be tested. At 1610, additional modes that are suppressed by WAIP substitution and / or disallowed due to the size of the current block (e.g., disallowed in the test list) may be tested. At 1612, weights w0,w1 associated with the intra-prediction modes may be calculated for blending. At 1614, the current block may be predicted via the mode of index i0 or by blending two predictions from the mode of index w0,w1 with weights i0,i1.

[0149] As shown in FIG. 17, 1702 to 1712 may include steps related to the derivation step of the TIMD procedure, and 1714 may be associated with the prediction step of the TIMD procedure. FIG. 17 illustrates an example of a TIMD derivation procedure for a current block to be predicted, for example, when / if one or more additional directional intra-prediction modes are allowed, for example, as described herein. At 1702, additional modes that are suppressed by the WAIP permutation and / or not allowed due to the size of the current block (e.g., not allowed in the test list) may be tested. At 1704, an MPM list for the current block may be collected. At 1706, a test list of intra-prediction modes may be constructed. Selected candidate intra-prediction modes may be tested from the MPM list. Default modes (e.g., DC, horizontal, and / or vertical) may be included. At 1708, modes (e.g., several modes) in the test list may be tested, and a WAIP permutation may be applied for the test (e.g., each test). At 1710, the extension (e.g., several extension) direction intra prediction modes near i0 and i1 may be tested. At 1712, weights w0,w1 associated with the intra prediction modes may be calculated for blending. At 1714, the current block may be predicted via the mode of index i0 or by blending two predictions from the modes of indexes w0,w1 with weights i0,i1.

[0150] In an example (e.g., with additional testing), a given block may be predicted based on (e.g., all) additionally allowed intra-prediction modes that are tested (e.g., systematically) during the TIMD derivation procedure.

[0151] In an example (e.g., involving additional testing), the additionally allowed intra prediction modes may be tested based on (e.g., under) certain circumstances. For example, if the closest non-wide intra prediction mode to the additionally allowed intra prediction mode belongs to the test list (e.g., if the non-wide intra prediction mode was or will be tested during the TIMD derivation procedure), one or more additionally allowed intra prediction modes may be tested (e.g., during the TIMD derivation procedure). For example, the TIMD derivation procedure may be implemented for the current 8×4 luminance CB. The directional intra prediction mode replaced by WAIP may be allowed. The additionally allowed intra prediction mode index may belong to [|2,12|], for example, as shown in Table 2. For example, if the intra prediction mode of index 13 belongs to the test list, the additionally allowed intra prediction modes (e.g., all additionally allowed intra prediction modes) may be tested. In another example (e.g., during the TIMD derivation procedure), if the closest non-wide intra prediction mode to the additionally allowed intra prediction mode belongs to the test list (e.g., if the non-wide intra prediction mode was or will be tested during the TIMD derivation procedure), one or more additionally allowed intra prediction modes may be tested.

[0152]

number

[0153]

number

[0154] In an example (e.g., involving additional testing), an additionally allowed intra-prediction mode may be tested if / when at least one of the directional intra-prediction modes having an opposite direction to the additionally allowed mode belongs to the test list.

[0155] In an example (e.g., involving additional testing), the decision to test an additional allowed intra-prediction mode may depend on the SATD between the template of the current block and the prediction of the template via the intra-prediction modes already tested. In an example, for a non-wide-angle intra-prediction mode that is closest to the additional allowed intra-prediction mode, the SATD between the template of the current block and the mode prediction is the smallest among the modes tested so far.

[0156]

number

[0157]

number

[0158] The intra prediction mode used by the TIMD and WAIP may be stored. The intra prediction mode to be stored may be used, for example, to generate an MPM list of luminances CB surrounding the current luminance CB. The stored mode may be, for example, the closest mode or the backward mode.

[0159] The closest mode 130 may be stored, for example, if the mode selected by the TIMD is in the range [|131, 141|] for a square luminance CB, modes for close shaped CUs are allowed, and angular modes in the range [|2, 130|] (e.g., complemented by planar and DC modes) are used without additional modes. In another example, mode 2 may be stored if an angular mode in the range [|-9, 1|] is selected. In another example with a luminance CB of size 16×8 with allowed angular modes [|13, 141|], mode 13 may be stored if the selected mode is smaller than 13, and mode 141 may be stored if the selected mode is larger than 141.

[0160] In one example of storing a mode with an opposite direction, if the mode selected by the TIMD was the original mode 2, 45° from the bottom left, and mode 2 was removed in a horizontal block, the stored mode could be the original mode 130, 45° from the top right. In one example of a square luminance CB, the stored mode could be equal to 128 plus the value of the mode used when the mode used is below 34 (e.g., a fully horizontal mode). In one example of a square luminance CB, the stored mode could be equal to the mode used minus 128 when the mode used is above 98 (e.g., a fully horizontal mode). In an example (e.g., even with WAIP), there may not be a mode opposite to the mode between 34 and 98 because such an opposite mode uses a reference sample below the current luminance CB.

[0161] For example, an additional flag may be stored to signal that the mode used by the TIMD is not the mode that would have been used for (e.g., normal) intra prediction for the block shape to allow the correct mode to be stored.

[0162] The TIMD may be provided with additional decoded reference samples. During the TIMD derivation procedure, the intra-prediction modes replaced by the WAIP process may be tested following the allowance of the additional modes. The process of predicting the template of the current block from the decoded reference samples of the template may lack decoded reference samples. During the prediction step via the TIMD, the process of predicting the current block from its decoded reference samples may lack decoded reference samples if, for example, an intra-prediction mode that is replaced by WAIP but allowed following the allowance of the additional modes is selected. Providing the additional decoded reference samples to the TIMD may compensate (e.g., make up for) the lack of decoded reference samples during TIMD derivation and / or prediction via TIMD.

[0163] For additionally allowed intra-prediction modes, decoded reference samples may be added. Decoded reference samples may be added for a given block to be predicted (e.g., during TIMD derivation and / or prediction via TIMD) for additionally allowed intra-prediction modes (e.g., allowed as described herein). At least one decoded reference sample may be added for a first intra-prediction mode (e.g., an intra-prediction mode that is excluded from the test list or not allowed to be tested due to wide-angle intra-prediction (WAIP) permutation). The added decoded reference samples may correspond to decoded reference samples that may be used for prediction.

[0164] In the example of a rectangular WxH block (W>H), one or more intra prediction modes may be allowed that are replaced by the WAIP process. Prediction may occur via TIMD. W decoded reference samples below the current block may be considered for prediction via additionally allowed intra prediction modes (e.g., similar to a square WxW block). Figures 18A-18C illustrate an example of adding decoded reference samples for TIMD derivation and prediction via TIMD. In the example of a WxH rectangular block (H>W), H decoded reference samples to the right of the current block may be considered for prediction via additionally allowed intra prediction modes (e.g., similar to a square HxH block). Figures 19A-19C illustrate an example of adding decoded reference samples for TIMD derivation and prediction via TIMD. As shown by the examples of Figures 18A-18C and 19A-19C, the dashed line indicates an angle of +45 degrees in the clockwise direction. 18A-18C show the bottom-most decoded reference sample extrapolated by the intra-prediction mode of index 2 using the mode indexing in the ECM (e.g., for TIMD derivation and prediction via TIMD) (e.g., without considering the interpolation of decoded reference samples for directional modes). FIG. 19A-19C show the right-most decoded reference sample extrapolated by the intra-prediction mode of index 130 using the mode indexing of TIMD in the ECM (e.g., for TIMD derivation and prediction via TIMD) (e.g., without considering the interpolation of decoded reference samples for directional modes). The dashed line depicts the last decoded reference sample that may be used (e.g., exclusively) for prediction (e.g., without considering the interpolation of decoded reference samples for directional modes and PDPC).

[0165] 18A-18C illustrate an example of adding decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxH block, W>H, to be predicted, when one or more directional intra-prediction modes replaced by WAIP are allowed. As shown in FIG. 18A, a current block (1803) may be surrounded by TIMD templates (1800 and 1801) during TIMD derivation. The tested intra-prediction modes may predict the template of the current block from the decoded reference samples of the template (1802 and 1804). The added decoded reference samples (e.g., for one or more allowed additional directional intra-prediction modes replaced by WAIP) are shown at 1804. As shown in FIG. 18B and FIG. 18C, during prediction via TIMD, (e.g., each) intra-prediction mode derived via TIMD may predict the current block (1803) from the associated decoded reference samples (1805 and 1806). The added decoded reference samples (e.g., for one or more allowed additional directional intra-prediction modes replaced by WAIP) are indicated at 1806. Figure 18B illustrates an example of prediction via TIMD when the MRL index indicated by multiRefIdx is equal to 0. Figure 18C illustrates an example of prediction via TIMD when multiRefIdx>0.

[0166] 19A-19C illustrate an example of adding decoded reference samples during TIMD derivation and prediction via TIMD for a rectangular WxH block, H>W, to be predicted, when one or more directional intra-prediction modes replaced by WAIP are allowed. As shown in FIG. 19A, a current block (1903) may be surrounded by TIMD templates (1900 and 1901) during TIMD derivation. The tested intra-prediction modes may predict the template of the current block from the decoded reference samples of the template (1902 and 1904). The added decoded reference samples (e.g., for one or more allowed additional directional intra-prediction modes replaced by WAIP) are shown at 1904. As shown in FIG. 19B and FIG. 19C, during prediction via TIMD, (e.g., each) mode derived via TIMD may predict the current block (1903) from the associated decoded reference samples (1905 and 1906). The added decoded reference samples (e.g., for one or more allowed additional directional intra-prediction modes replaced by WAIP) are indicated at 1906. Figure 19B illustrates an example of prediction via TIMD when the MRL index indicated by multiRefIdx is equal to 0. Figure 19C illustrates an example of prediction via TIMD when multiRefIdx>0.

[0167] In an example (e.g., during TIMD derivation for a rectangular WxH block (W>H)), more decoded reference samples of the template of the current block located at the bottom of the current block may be extracted for prediction via additionally allowed intra-prediction modes. In an example (e.g., during TIMD derivation for a rectangular WxH block (H>W)), more decoded reference samples of the template of the current block located at the rightmost part of the current block may be extracted for prediction via additionally allowed intra-prediction modes. Figures 20 and 21 show examples of extracting more decoded reference samples for prediction, compared to Figures 18 and 19, respectively.

[0168] 20A-20C illustrate an example of adding decoded reference samples during TIMD derivation (e.g., 20A) and prediction via TIMD (e.g., 20B and 20C) for a rectangular WxH block to be predicted, W>H, when one or more directional intra-prediction modes replaced by WAIP are allowed. As shown in FIG. 20A, a current block (2003) (e.g., a horizontal and rectangular current block) may be surrounded by a TIMD template (2000 and 2001) during TIMD derivation. The tested intra-prediction modes may predict the template of the current block from the decoded reference samples of the template (2002 and 2004). The added decoded reference samples (e.g., for one or more allowed additional directional intra-prediction modes replaced by WAIP) are shown at 2004. As shown in Figures 20B and 20C, during prediction via TIMD, (e.g., each) intra-prediction mode derived via TIMD may predict the current block (2003) from associated decoded reference samples (2005 and 2006). Added decoded reference samples (e.g., for one or more allowed additional directional intra-prediction modes replaced by WAIP) are shown at 2006.

[0169] 21A-21C illustrate an example of adding decoded reference samples during TIMD derivation (e.g., 21A) and prediction via TIMD (e.g., 21B and 21C) for a rectangular WxH block to be predicted, H>W, when one or more directional intra-prediction modes replaced by WAIP are allowed. As shown in FIG. 21A, a current block (2103) (e.g., a vertical and rectangular current block) may be surrounded by a TIMD template (2100 and 2101) during TIMD derivation. The tested intra-prediction modes may predict the template of the current block from the decoded reference samples of the template (2102 and 2104). The added decoded reference samples (e.g., for one or more allowed additional directional intra-prediction modes replaced by WAIP) are shown at 2004. As shown in Figures 21B and 21C, during prediction via TIMD, (e.g., each) intra-prediction mode derived via TIMD may predict the current block (2103) from associated decoded reference samples (2105 and 2106). Added decoded reference samples (e.g., for one or more allowed additional directional intra-prediction modes replaced by WAIP) are shown at 2106.

[0170] In examples (e.g., as shown in Figures 18A-18C, 19A-19C, 20A-20C, and 21A-21C), the current block may be predicted by substituting unavailable decoded reference samples in each set of decoded reference samples. The substitution may, for example, replace unavailable decoded reference samples according to the substitution implemented in VVC and ECM. The examples described herein (e.g., as shown in Figures 18A-18C, 19A-19C, 20A-20C, and 21A-21C) may be adapted or generalized to prediction for the current block based on a portion of the template being available and, for example, another portion of the template being outside the boundaries of the current frame.

[0171] In an example (e.g., for a current block of a size using TIMD), additionally allowed intra prediction modes (e.g., intra prediction modes replaced by WAIP) may be allowed for blocks of a near shape. Decoded reference samples used by allowed intra prediction modes for blocks of a near shape may be extracted (e.g., when possible) for TIMD derivation and prediction using TIMD. In one example (e.g., a current WxW block is predicted), a near shape CU may have width / height ratios of 1 / 2 and 2 / 1. Prediction via TIMD may consider decoded reference samples 2W below the current block and decoded reference samples 2W to the right of the current block to predict via additionally allowed intra prediction modes (e.g., as shown by examples in Figures 22A-22C). As shown in Figure 22B, the dashed lines indicate two angles of two extra wide angle intra prediction modes that are additionally allowed (e.g., allowing modes allowed for CUs of a near shape). An extremely wide intra prediction mode for a wide intra prediction mode propagating from top right to bottom left may refer to the mode with the smallest angle with the horizontal axis in absolute value, and an extremely wide intra prediction mode for a wide intra prediction mode propagating from bottom left to top right may refer to the mode with the smallest angle with the vertical axis.

[0172] 22A-22C illustrate an example of adding decoded reference samples during TIMD derivation (e.g., 22A) and prediction via TIMD (e.g., 22B and 22C) for a square WxW block to be predicted. A current block (2203) may be surrounded by associated TIMD templates (2200 and 2201) during TIMD derivation. A tested intra-prediction mode may predict a template of the current block from the decoded reference samples of the template (2202 and 2204). The added decoded reference samples (e.g., according to one or more embodiments described herein) are indicated at 2204. A (e.g., each) prediction mode derived via TIMD may predict the current block (2203) from associated decoded reference samples (2205 and 2206) during prediction via TIMD. The added decoded reference samples according to the first embodiment may be indicated at 2206. Figure 22B illustrates an example of prediction via TIMD when the MRL index indicated by multiRefIdx is equal to 0. Figure 22C illustrates an example of prediction via TIMD when multiRefIdx>0.

[0173] In the example, additional decoded reference samples of the template of the current block may be extracted (e.g., during TIMD derivation) for prediction via additionally allowed intra-prediction modes. The additional decoded reference samples may be located at the bottom of the current block and the rightmost part of the current block. The examples shown in Figures 23A to 23C may be compared with the examples shown in Figures 22A to 22C for a better understanding of the examples.

[0174] 23A-23C illustrate an example of adding decoded reference samples during TIMD derivation (e.g., 23A) and prediction via TIMD (e.g., 23B and 23C) for a rectangular WxW block to be predicted. A current block (2303) may be surrounded by associated TIMD templates (2300 and 2301) during TIMD derivation. A tested intra prediction mode may predict a template of the current block from the decoded reference samples of the template (2302 and 2304). The added decoded reference samples (e.g., according to one or more embodiments described herein) are indicated at 2304. A (e.g., each) prediction mode derived via TIMD may predict the current block (2303) from associated decoded reference samples (2305 and 2306) during prediction via TIMD. The added decoded reference samples according to the first embodiment may be indicated at 2306.

[0175] Although the features and elements are described above in certain combinations, one skilled in the art will understand that each feature or element may be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware embodied 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 memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. 1. A video decoding device comprising a processor, the processor comprising: Obtain a Most Probable Mode (MPM) list associated with the current block; determining a test list of intra-prediction modes from the MPM list; testing a first intra-prediction mode that is excluded from the test list or not allowed to be tested due to a wide-angle intra-prediction (WAIP) substitution; generating a prediction for the current block based on the tested intra-prediction modes; The video decoding device, further configured to decode the current block using the prediction.

2. The processor, testing a second intra-prediction mode included in the test list; 2. The video decoding device of claim 1, further configured to generate the prediction for the current block based on the tested first intra-prediction mode and the tested second intra-prediction mode test.

3. The video decoding device of claim 2 , wherein the testing of the first intra-prediction mode occurs prior to the determination of the test list.

4. The video decoding device of claim 2 , wherein the current block is associated with a first shape and the first intra-prediction mode is associated with a second shape.

5. 5. The video decoding device of claim 4, wherein the first shape is a rectangle and the second shape is a square, and adjacent sides of the first shape have different lengths.

6. 5. The video decoding device of claim 4, wherein the first shape is a square and the second shape is a rectangle, and adjacent sides of the second shape have different lengths.

7. The processor, 2. The video decoding device of claim 1, further configured to generate a plurality of indexes of intra-prediction modes, the plurality of indexes of intra-prediction modes being used to generate the prediction for the current block.

8. The processor, 8. The video decoding device of claim 7, further configured to calculate weights for the plurality of indexes of intra-prediction modes, at least one of the weights being a sum of absolute transform differences (SATD), and the prediction for the current block being generated further based on a subset of indexes of intra-prediction modes having a minimum prediction SATD from the plurality of indexes of intra-prediction modes.

9. The video decoding device of claim 1 , wherein the generated prediction is further based on the calculated weights.

10. 10. The video decoding device of claim 9, wherein the calculated weights include a first calculated weight associated with the first intra-prediction mode tested and a second calculated weight associated with the second intra-prediction mode tested.

11. The video decoding device of claim 1 , wherein the processor is further configured to add at least one decoded reference sample for the first intra-prediction mode.

12. 1. A video encoding device comprising a processor, the processor comprising: Obtain a Most Probable Mode (MPM) list associated with the current block; determining a test list of intra-prediction modes from the MPM list; testing a first intra-prediction mode that is excluded from the test list or not allowed to be tested due to a wide-angle intra-prediction (WAIP) substitution; generating a prediction for the current block based on the tested intra-prediction modes; The video encoding device, further configured to encode the current block using the prediction.

13. The processor, testing a second intra-prediction mode included in the test list; 13. The video decoding device of claim 12, further configured to generate the prediction for the current block based on the tested first intra-prediction mode and the tested second intra-prediction mode test.

14. The video encoding device of claim 13 , wherein the testing of the first intra-prediction mode occurs prior to the determination of the test list.

15. The video encoding device of claim 13 , wherein the current block is associated with a first shape and the first intra-prediction mode is associated with a second shape.

16. 16. The video encoding device of claim 15, wherein the first shape is a rectangle and the second shape is a square, and adjacent sides of the first shape have different lengths.

17. 16. The video encoding device of claim 15, wherein the first shape is a square and the second shape is a rectangle, and adjacent sides of the second shape have different lengths.

18. The processor, 13. The video encoding device of claim 12, further configured to generate a plurality of indexes of intra-prediction modes, the plurality of indexes of intra-prediction modes being used to generate the prediction for the current block.

19. The processor, 20. The video encoding device of claim 18, further configured to calculate weights for the plurality of indexes of intra-prediction modes, at least one of the weights being a sum of absolute transform differences (SATD), and the prediction for the current block being generated further based on a subset of indexes of intra-prediction modes having a minimum prediction SATD from the plurality of indexes of intra-prediction modes.

20. The video encoding device of claim 12 , wherein the generated prediction is further based on the calculated weights.

21. 21. The video encoding device of claim 20, wherein the calculated weights include a first calculated weight associated with the first intra-prediction mode tested and a second calculated weight associated with the second intra-prediction mode tested.

22. The video encoding device of claim 12 , wherein the processor is further configured to add at least one decoded reference sample for the first intra-prediction mode.

23. The device of any preceding claim, further comprising a memory operatively connected to the processor.

24. 1. A method for a video decoder, the method comprising: Obtaining a Most Probable Mode (MPM) list associated with a current block; determining a test list of intra-prediction modes from the MPM list; testing a first intra-prediction mode that is excluded from the testing list or not allowed to be tested due to a wide-angle intra-prediction (WAIP) substitution; generating a prediction for the current block based on the tested intra-prediction modes; and decoding the current block using the prediction.

25. The method further comprising: testing a second intra-prediction mode included in the test list; and 25. The method of claim 24, further comprising: generating the prediction for the current block based on the tested first intra-prediction mode and the tested second intra-prediction mode test.

26. The method of claim 25 , wherein the testing of the first intra-prediction mode occurs prior to the determination of the test list.

27. 26. The method of claim 25, wherein the current block is associated with a first shape and the first intra-prediction mode is associated with a second shape.

28. 28. The method of claim 27, wherein the first shape is a rectangle and the second shape is a square, and adjacent sides of the first shape have different lengths.

29. 28. The method of claim 27, wherein the first shape is a square and the second shape is a rectangle, and adjacent sides of the second shape have different lengths.

30. The method further comprising:

25. The method of claim 24, further comprising generating a plurality of indexes of intra-prediction modes, the plurality of indexes of intra-prediction modes being used to generate the prediction for the current block.

31. The method further comprising:

31. The method of claim 30, further comprising: calculating weights for the plurality of indexes of intra-prediction modes, at least one of the weights being a sum of absolute transform differences (SATD), and the prediction for the current block is further based on a subset of the indexes of intra-prediction modes having a minimum predicted SATD from the plurality of indexes of intra-prediction modes.

32. The method of claim 24 , wherein the generated prediction is further based on the calculated weights.

33. 33. The method of claim 32, wherein the calculated weights include a first calculated weight associated with the first intra-prediction mode tested and a second calculated weight associated with the second intra-prediction mode tested.

34. 25. The video decoding device of claim 24, the method further comprising adding at least one decoded reference sample for the first intra-prediction mode.

35. 1. A method for a video encoder, the method comprising: Obtaining a Most Probable Mode (MPM) list associated with a current block; determining a test list of intra-prediction modes from the MPM list; testing a first intra-prediction mode that is excluded from the testing list or not allowed to be tested due to a wide-angle intra-prediction (WAIP) substitution; generating a prediction for the current block based on the tested intra-prediction modes; encoding the current block using the prediction.

36. The method further comprising: testing a second intra-prediction mode included in the test list; and 36. The method of claim 35, further comprising: generating the prediction for the current block based on the tested first intra-prediction mode and the tested second intra-prediction mode test.

37. 37. The method of claim 36, wherein the testing of the first intra-prediction mode occurs prior to the determination of the test list.

38. 37. The method of claim 36, wherein the current block is associated with a first shape and the first intra-prediction mode is associated with a second shape.

39. 39. The method of claim 38, wherein the first shape is a rectangle and the second shape is a square, and adjacent sides of the first shape have different lengths.

40. 39. The method of claim 38, wherein the first shape is a square and the second shape is a rectangle, and adjacent sides of the second shape have different lengths.

41. The method further comprising:

36. The method of claim 35, further comprising generating a plurality of indexes of intra-prediction modes, the plurality of indexes of intra-prediction modes being used to generate the prediction for the current block.

42. The method further comprising:

42. The method of claim 41, further comprising: calculating weights for the plurality of indexes of intra-prediction modes, at least one of the weights being a sum of absolute transform differences (SATD), and the prediction for the current block is further based on a subset of the indexes of intra-prediction modes having a minimum predicted SATD from the plurality of indexes of intra-prediction modes.

43. 36. The method of claim 35, wherein the generated prediction is further based on the calculated weights.

44. 44. The method of claim 43, wherein the calculated weights include a first calculated weight associated with the first intra-prediction mode tested and a second calculated weight associated with the second intra-prediction mode tested.

45. 36. The method of claim 35, the method further comprising adding at least one decoded reference sample for the first intra-prediction mode.

46. A computer program product comprising program code instructions stored on a non-transitory computer readable medium and for implementing the steps of the method according to at least one of claims 24 to 45 when executed by a processor.

47. A computer program comprising program code instructions for implementing the steps of the method according to at least one of claims 24 to 45, when the computer program is executed by a processor.

48. Video data comprising information representative of coding blocks encoded according to one of the methods of any one of claims 35 to 45.

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