Adaptive streaming of geometry-based point clouds

Abstract

To provide a device and a method for receiving a content related to a geometry-based point cloud.SOLUTION: A client device receives a media presentation description (MPD) file from a content server, identifies from the MPD file a set of pre-selection elements and one or more adaptation sets indicated by attributes associated with at least one pre-selection element of the set of pre-selection elements, determines a geometry-based point cloud compression (GPCC) tile identifier associated with a viewport based on a received first descriptor in the MPD file, selects one or more adaptation sets associated with the GPCC tile identifier using a second descriptor, and requests and receives a point cloud component associated with the selected one or more adaptation sets.SELECTED DRAWING: None

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 042,481, filed June 22, 2020, and U.S. Provisional Patent Application No. 63 / 084,758, filed September 29, 2020, the disclosures of which are incorporated herein by reference in their entireties. [Background technology]

[0002] Video coding systems may be used to compress digital video signals to, for example, reduce the storage capacity and / or transmission bandwidth required for such signals. Video coding systems may include, for example, wavelet-based systems, object-based systems, and / or block-based hybrid video coding systems. Video coding systems may support point cloud coding and storage aspects. However, these systems may lack sufficient mechanisms to support streaming point cloud data over a network. Summary of the Invention

[0003] Systems, methods, and means are disclosed for adaptive streaming of visual media content, such as geometry-based point clouds. Elements, attributes, and metadata associated with point cloud components may be signaled, for example, to enable a streaming client to identify point cloud streams and component substreams of these point cloud streams in a media presentation descriptor (MPD) and to enable the streaming client to select versions of the point cloud and / or point cloud components, for example, based on client support. In embodiments, a streaming client may utilize guidance (e.g., instructions signaled in an MPD file) to make decisions regarding various representations of the point cloud content. For example, the instructions may indicate which set of representations across various point cloud components constitutes a particular quality level. Components of the point cloud content may be divided into multiple tiles or tile portions. A client may stream specific tile portions (e.g., selected tile portions) of a geometry component (e.g., instead of streaming all point cloud data) based on bandwidth availability, for example. The tile bitstreams of a point cloud component may be available in different adaptation sets, eg, an adaptation set (eg, each adaptation set) may represent a tile of the point cloud component.

[0004] Geometry-based point cloud compression (G-PCC) components may be signaled in dynamic streaming over HTTP (DASH). For example, G-PCC components may be signaled using a DASH manifest file or an MPD file. In an embodiment, G-PCC components (e.g., each G-PCC component) may be represented as an adaptation set (e.g., a separate adaptation set) in a DASH MPD file. An adaptation set (e.g., a main adaptation set) may serve as a main access point for G-PCC content. In an embodiment, an adaptation set (e.g., one adaptation set) may be signaled per component per resolution.

[0005] The G-PCC component descriptor may be signaled, for example, to enable a streaming client to identify the adaptation set and / or type of point cloud component in the representation. The G-PCC descriptor may enable a streaming client to distinguish between different point cloud streams present in an MPD file. The streaming client may identify the component streams for each point cloud stream.

[0006] G-PCC preselection may be signaled (e.g., in the MPD) with an identifier (ID) list that includes, for example, the ID of the main adaptation set of the volumetric media and the IDs of the adaptation sets that correspond to the G-PCC components. Preselection may be signaled, for example, using a preselection element within a Period element and / or using a preselection descriptor at the adaptation set level.

[0007] Multiple versions of G-PCC media may be signaled. Multiple versions of the same point cloud media may be signaled, for example, using separate preselections. Preselections representing alternative versions of the same geometry-based point cloud media may, for example, include G-PCC descriptors with the same attribute values.

[0008] One or more G-PCC tiles may be signaled. Tile bounding box information may be signaled, for example, if multiple tiles exist in a geometry-based point cloud. A client may select a tile ID from tile inventory bounding box information (e.g., in an MPD) to stream tiled G-PCC component data, for example.

[0009] A client may identify the tile IDs of point cloud components in an adaptation set, for example, by checking the G-PCC component descriptor. The G-PCC tile ID descriptor may be signaled, for example, to allow a streaming client to distinguish between G-PCC tile streams.

[0010] Characteristics of spatial regions and / or mappings between these regions and G-PCC tiles may be signaled, for example, when 3D spatial regions in geometry-based volumetric media content are static. Characteristics of spatial regions and / or mappings between these regions and corresponding adaptation sets of G-PCC components may be signaled (e.g., using G-PCC 3D region descriptors), for example, when 3D spatial regions are static and / or tile inventory information is not available. Mappings between spatial regions and corresponding adaptation sets of G-PCC components may be signaled (e.g., by G-PCC region ID descriptors or G-PCC component descriptors).

[0011] A timed metadata track (e.g., indicating the position and / or dimensions of the 3D region on the presentation timeline) may be signaled in the adaptation set (e.g., for a dynamic spatial region), e.g., together with the representation, and associated with the main G-PCC adaptation set.

[0012] Streaming client behavior can be based on signaling: DASH clients can be guided by information provided in the MPD, for example.

[0013] Systems, methods, and means are disclosed for receiving content related to a geometry-based point cloud. In an embodiment, a Media Presentation Description (MPD) file may be received, for example, from a content server. A set of preselection elements may be identified from the MPD file. One or more adaptation sets associated with at least one preselection element of the set of preselection elements may be identified. For example, the one or more adaptation sets may be indicated by an attribute associated with one of the preselection elements.

[0014] A geometry-based point cloud compression (GPCC) tile identifier associated with the viewport may be determined. For example, the GPCC tile identifier may be determined based on a received first descriptor in the MPD file. In an embodiment, the first descriptor may be a three-dimensional (3D) region descriptor. The 3D region descriptor may include a region location, one or more region dimensions, and / or a set of tiles associated with the 3D region.

[0015] One or more adaptation sets associated with the GPCC tile identifiers may be selected using a second descriptor. In an embodiment, the second descriptor may be a component descriptor. The component descriptor may include a component type, an attribute type, an index, and / or a set of tiles associated with the bitstream. Point cloud components associated with the selected one or more adaptation sets may be requested. In an embodiment, the point cloud components may be received.

[0016] Each feature disclosed anywhere in this specification is described and can be implemented separately / individually, as well as in combination with any other feature disclosed herein and / or with any feature disclosed elsewhere that may be implicitly or explicitly referenced herein or that may otherwise fall within the scope of the subject matter disclosed herein. [Brief explanation of the drawings]

[0017] [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 exemplary wireless transmit / receive unit (WTRU) that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 1C] 1A 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 illustrated in FIG. 1A, according to one embodiment. [Figure 1D] 1B is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 2] FIG. 1 illustrates an exemplary video encoder. [Figure 3]FIG. 1 illustrates an embodiment of a video decoder. [Figure 4] FIG. 1 illustrates an example system in which various aspects and embodiments may be implemented. [Figure 5] 1 illustrates an example of a bitstream structure for geometry-based point cloud compression (G-PCC). [Figure 6] 10 shows an example structure example where the G-PCC geometry and attribute bitstreams are stored in a single track. [Figure 7] 1 shows an example of a multi-track G-PCC container. [Figure 8] 1 illustrates an exemplary Media Presentation Description (MPD) hierarchical data model. [Figure 9] 10 shows an example of using preselection to group G-PCC components in an MPD. [Figure 10] 10 shows an example of using preselection to group multiple versions of a G-PCC component in an MPD. [Figure 11] 10 shows an example of G-PCC content with multiple tile tracks. DETAILED DESCRIPTION OF THE INVENTION

[0018] A detailed description of illustrative embodiments will now be described with reference to various figures. While the description provides detailed examples of possible implementations, it should be noted that the details are intended to be illustrative and in no way limit the scope of the present application.

[0019] 1A illustrates an exemplary communication system 100 in which one or more disclosed embodiments may be implemented. Communication system 100 may be a multiple-access system that provides content, such as voice, data, video, messaging, broadcasts, etc., to multiple wireless users. Communication system 100 may enable multiple wireless users to access such content through sharing of system resources, including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multicarrier (FBMC), etc.

[0020] 1A, communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RANs 104 / 113, CNs 106 / 115, public switched telephone network (PSTN) 108, the 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, pagers, cellular phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearables, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain contexts), consumer electronics devices, devices operating in commercial and / or industrial wireless networks, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be referred to interchangeably as a UE.

[0021] The communications 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 communications networks, such as the CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an eNodeB, a Home Node B, a Home eNodeB, 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 shown 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.

[0022] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), a relay node, etc. The base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies, which may be referred to as a cell (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 per sector of the cell, for example, using beamforming to transmit and / or receive signals in desired spatial directions.

[0023] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0024] More specifically, as noted above, the communications system 100 may be a multiple-access system and may use one or more channel access schemes, such as, for example, CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114 a and the WTRUs 102 a, 102 b, 102 c 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).

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

[0026] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using New Radio (NR).

[0027] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may jointly implement LTE radio access and NR radio access, 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).

[0028] 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.

[0029] 1A may be, for example, a wireless router, a Home Node B, a Home eNode B, or an access point and may utilize any suitable RAT to facilitate wireless connectivity in a local area such as a location such as a business, 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 through the CN 106 / 115.

[0030] 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 different throughput, latency, error tolerance, reliability, data throughput, and mobility requirements. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calls, Internet connectivity, video distribution, and / or perform high-level security functions such as user authentication. Although not shown in FIG. 1A , it will be understood that the RAN 104 / 113 and / or the CN 106 / 115 may communicate directly or indirectly with other RANs employing 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) employing GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0031] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a public 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 the transmission control protocol (TCP), user datagram protocol (UDP), and / or the internet protocol (IP) of the TCP / IP Internet protocol suite. The network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the network 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0032] Some or all of the WTRUs 102a, 102b, 102c, 102d in the 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 that may use a cellular-based wireless technology and a base station 114b that may use an IEEE 802 wireless technology.

[0033] 1B is a system diagram illustrating an example WTRU 102. As shown in FIG. 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.

[0034] 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. While FIG. 1B depicts 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.

[0035] The transmit / receive element 122 may be configured to transmit signals to or receive signals 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 understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0036] 1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may use MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0037] The transceiver 120 may be configured to modulate signals 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 NR and IEEE 802.11.

[0038] 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. Furthermore, 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 and store data in memory that is not physically located on the WTRU 102, such as on a server or home computer (not shown).

[0039] The processor 118 may receive power from the power source 134, but 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.

[0040] 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 instead 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 being 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 location-determination method while remaining consistent with an embodiment.

[0041] 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, etc. The peripheral device 138 may include one or more sensors, which may be one or more of a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, a direction sensor, a proximity sensor, a temperature sensor, a time sensor, a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0042] The WTRU 102 may include a full-duplex radio where transmission and reception of some or all of the signals (e.g., associated with a particular subframe for both the UL (e.g., for transmission) and 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 through hardware (e.g., chokes) or processor-based signal processing (e.g., via a separate processor (not shown) or processor 118). In one embodiment, the WTRU 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 downlink (e.g., for reception)).

[0043] 1C is a system diagram illustrating the RAN 104 and the CN 106 according to one embodiment. As mentioned above, the RAN 104 may communicate with the WTRUs 102a, 102b, 102c over the air interface 116 using E-UTRA radio technology. The RAN 104 may also communicate with the CN 106.

[0044] The RAN 104 may include eNodeBs 160a, 160b, and 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, and 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In an embodiment, the eNodeBs 160a, 160b, and 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.

[0045] 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, user scheduling, etc. in the UL and / or DL. As shown in FIG. 1C, the eNodeBs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0046] 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.

[0047] 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 attach of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies such as GSM and / or WCDMA.

[0048] The SGW 164 may be connected to each of the eNode-Bs 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-eNode-B handovers, 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.

[0049] 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.

[0050] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional landline 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. Furthermore, 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.

[0051] Although the WTRU is depicted in FIGS. 1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments, such a terminal may use a wired communication interface (e.g., temporarily or permanently) with the communication network.

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

[0053] A WLAN in infrastructure Basic Service Set (BSS) mode may have an access point (AP) 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 a STA may arrive through the AP and be delivered to the STA. Traffic originating from a STA to a destination outside the BSS may be sent to the AP and transmitted to the respective destination. Traffic between STAs within the BSS may be transmitted, for example, through the AP; 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 transmitted between a source STA and a destination STA (e.g., directly between them) in 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 within or using the IBSS (e.g., all of the STAs) may communicate directly with each other. The IBSS mode of communication may be referred to herein as an "ad hoc" communication mode.

[0054] When using the 802.11ac infrastructure mode of operation or a similar mode of operation, an AP may transmit beacons on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width that is dynamically set via signaling. The primary channel may be the operating channel of the BSS and 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 / Collision Avoidance (CSMA / CA) with collision avoidance 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.

[0055] High Throughput (HT) STAs may use 40 MHz wide channels 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.

[0056] A Very High Throughput (VHT) STA may support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz and / or 80 MHz wide channels may be formed by combining 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).

[0057] 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 the TV White Space (TVWS) spectrum, while 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to representative embodiments, 802.11ah may support meter-type control / machine-type communications, such as MTC devices within macro coverage areas. MTC devices may have specific capabilities, including, for example, support for (e.g., only for) specific and / or limited bandwidths. MTC devices may include batteries with above-threshold battery life (e.g., to maintain very long battery life).

[0058] WLAN systems that can support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that can be designated as a primary channel. The primary channel can have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be configured and / or limited by the STAs among all STAs operating in the BSS that support the minimum bandwidth operating mode. In an 802.11ah example, the primary channel can 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 can depend on the condition of the primary channel. For example, if the primary channel is busy due to a STA (that only supports 1 MHz mode of operation) transmitting to the AP, the entire available frequency band may be considered busy, even though most of the frequency band may remain idle and be available for use.

[0059] In the United States, the available frequency band that can be used by 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz depending on the country code.

[0060] 1D is a system diagram illustrating the RAN 113 and the CN 115 according to one embodiment. As mentioned above, the RAN 113 may communicate with the WTRUs 102a, 102b, 102c over the air interface 116 using NR radio technology. The RAN 113 may also communicate with the CN 115.

[0061] The RAN 113 may include gNBs 180a, 180b, and 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, and 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, and 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to transmit and / or receive signals to the gNBs 180a, 180b, and 180c. Thus, the gNB 180a may, for example, transmit wireless signals to and / or receive wireless signals from the WTRU 102a using multiple antennas. In one embodiment, the gNBs 180a, 180b, and 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, and the remaining component carriers may be on a licensed spectrum. In one embodiment, the gNBs 180a, 180b, and 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 180c).

[0062] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with a 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).

[0063] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c 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 gNBs 180a, 180b, 180c while also communicating with and connecting to another RAN, such as eNodeBs 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, while the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

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

[0065] 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. While each of the foregoing elements is shown 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.

[0066] 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, and / or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0067] The SMFs 183a and 183b may be connected to the AMFs 182a and 182b in the CN 115 via an N11 interface. The SMFs 183a and 183b may also be connected to the UPFs 184a and 184b in the CN 115 via an N4 interface. The SMFs 183a and 183b may select and control the UPFs 184a and 184b and configure the routing of traffic through the UPFs 184a and 184b. The SMFs 183a and 183b may perform other functions, such as managing and assigning UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0068] The 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.

[0069] 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 acts as an interface between the CN 115 and the PSTN 108. Additionally, 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.

[0070] 1A-1D and their corresponding descriptions, 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, eNode-Bs 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 simulate network and / or WTRU functions.

[0071] The emulation devices may be designed to implement 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 devices may be directly coupled to another device for testing purposes and / or may perform testing using terrestrial wireless communication.

[0072] 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 implement testing of one or more components. One or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (which may include, e.g., one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0073] This application describes various aspects, including tools, features, examples or embodiments, models, approaches, and the like. Many of these aspects are described with specificity and, at least to illustrate their individual characteristics, are described in what may sometimes sound definitive terms. 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, aspects may similarly be combined and interchanged with aspects described in prior applications.

[0074] Aspects described and contemplated in this application may be implemented in many different forms. While Figures 5-8 described herein may provide some embodiments, other embodiments are also contemplated. Discussion of Figures 5-8 does not limit the scope of implementations. At least one of the 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.

[0075] 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.

[0076] Various methods are described herein, each of which includes one or more steps or actions for achieving the described method. Unless a specific order of steps or actions is required for proper operation of the method, the order and / or use of specific steps and / or actions may be modified or combined. Additionally, terms such as "first," "second," and the like may be used in various embodiments to modify elements, components, steps, operations, etc., such as, for example, "first decoding" and "second decoding." The use of such terms does not imply a modified ordering of operations unless specifically required. Thus, in this example, the first decoding need not be performed before the second decoding, but may occur, for example, before, during, or during an overlapping time with the second decoding.

[0077] Various methods and other aspects described herein may modify (e.g., be used to modify) modules of the video encoder 200 and video decoder 300, as shown in Figures 2 and 3, respectively, such as pre-encoding 201, intra prediction 260, entropy coding 245 and / or entropy decoding module 330, intra prediction 360, and post-decoding 385. Furthermore, the subject matter disclosed herein presents aspects that are not limited to VVC or HEVC and 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 standard and recommendation (including, for example, VVC and HEVC). Unless otherwise indicated or technically excluded, aspects described herein may be used individually or in combination.

[0078] Various numerical values ​​are used in the embodiments described herein, such as minimum and maximum value ranges (e.g., 0 to 1, 0 to N, or 0 to 255), bit values ​​for indications or decisions, default values, ID numbers (e.g., for adaptive ID), etc. These and other specific values ​​are for purposes of describing the embodiments, and the described aspects are not limited to these specific values.

[0079] 2 illustrates an exemplary video encoder. While variations of exemplary encoder 200 are contemplated, encoder 200 is described below for clarity without describing all possible variations.

[0080] Before being encoded, a video sequence may undergo encoding pre-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.

[0081] 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 units of 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 determines (205) whether to use intra mode or inter mode to code the unit, and indicates the intra / inter decision, for example, via a prediction mode flag. A prediction residual is calculated (210), for example, by subtracting the predicted block from the original image block.

[0082] The prediction residual is then transformed (225) and quantized (230). The quantized transform coefficients, as well as motion vectors and other syntax elements, 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 the transform or quantization processes.

[0083] The encoder decodes the coded block to provide a reference for further prediction. The quantized transform coefficients are dequantized (240) and inverse transformed (250) to decode the prediction residual. The decoded prediction residual is combined with the predicted block (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) filtering to reduce coding artifacts. The filtered image is stored in a reference picture buffer (280).

[0084] Figure 3 illustrates an example of a video decoder. In the exemplary decoder 300, a bitstream is decoded by decoder elements as described below. The video decoder 300 generally performs a decoding pass that is the inverse of the encoding pass, as described in Figure 2. The encoder 200 may also generally perform video decoding as part of encoding the video data. For example, the encoder 200 may perform one or more of the video decoding steps presented herein. The encoder reconstructs decoded images and maintains synchronization with the decoder with respect to, for example, one or more of reference pictures, entropy coding contexts, and other decoder-related state variables.

[0085] In particular, the decoder's input includes a video bitstream, which may be generated by the video encoder 200. The bitstream is first entropy decoded (330) to obtain transform coefficients, motion vectors, and other coding information. Picture partition information indicates how the picture is partitioned. The decoder may then partition the picture according to the decoded picture partition information (335). The transform coefficients are dequantized (340) and inverse transformed (350) to decode the prediction residual. The decoded prediction residual is combined with a predicted block (355) to reconstruct an image block. The predicted block may be obtained from intra prediction (360) or 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).

[0086] The decoded picture may further undergo post-decoding processing (385), such as an inverse color conversion (e.g., YCbCr 4:2:0 to RGB 4:4:4 conversion) or an 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.

[0087] FIG. 4 illustrates an example 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 perform one or more of the aspects described herein. Examples of such devices include, but are not limited to, various electronic devices, such as personal computers, laptop computers, smartphones, tablet computers, digital multimedia set-top boxes, digital television receivers, personal video recording systems, connected home appliances, and servers. Elements of system 400, 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.

[0088] The system 400 includes at least one processor 410 configured to execute instructions loaded therein, for example, to implement various aspects described herein. The processor 410 may include embedded memory, input / output interfaces, and various other circuitry known in the art. The system 400 includes at least one memory 420 (e.g., a volatile memory device and / or a non-volatile memory device). The system 400 includes a storage device 440, which may include 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 drives, and / or optical disk drives. Storage devices 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.

[0089] System 400 includes an encoder / decoder module 430 configured to process data to provide, for example, encoded or decoded video, which may include its own processor and memory. Encoder / decoder module 430 represents a module that may be included within 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. Additionally, encoder / decoder module 430 may be implemented as a separate element of system 400 or may be incorporated within processor 410 as a combination of hardware and software, as known to those skilled in the art.

[0090] Program code loaded into the processor 410 or the encoder / decoder 430 to perform various aspects described herein may be stored in the storage device 440 and then loaded onto 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 the execution of the storage 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 operational logic.

[0091] 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 may 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, the external non-volatile flash memory is used to store, for example, the television's operating system. In at least one embodiment, a high-speed external dynamic volatile memory such as RAM is used as working memory for video encoding and decoding operations such as MPEG-2 (MPEG refers to the Moving Picture Experts Group, MPEG-2 is also referred to as ISO / IEC 13818, 13818-1 is also known as H.222, and 13818-2 is also known as H.262), HEVC (HEVC, High Efficiency Video Coding, also known as H.265 and MPEG-H Part 2), or VVC (Versatile Video Coding, a new standard being developed by JVET, the Joint Video Experts Team).

[0092] Input to the elements of system 400 may be provided through a variety of 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 (or a set of COMP inputs), (iii) a Universal Serial Bus (USB) input, and / or (iv) a High Definition Multimedia Interface (HDMI) input. Other examples include composite video, not shown in FIG. 4.

[0093] 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 bandlimiting a signal to a band of frequencies), (ii) downconverting the selected signal, (iii) bandlimiting 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 downconverted, bandlimited signal, (v) performing error correction, and (vi) demultiplexing to select a desired data packet stream. The RF section of various embodiments includes one or more elements that perform these functions, such as a frequency selector, a signal selector, a band limiter, a channel selector, a filter, a downconverter, a demodulator, an error corrector, and a demultiplexer. The RF section may include a tuner that performs various of these functions, including, for example, downconverting received signals to a lower frequency (e.g., an intermediate frequency or near-baseband frequency) or to baseband. In one embodiment of a set-top box, 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, downconverting, and re-filtering 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 that perform similar or different functions. Adding elements may include inserting elements between existing elements, such as inserting an amplifier and an analog-to-digital converter. In various embodiments, the RF section includes an antenna.

[0094] Additionally, the USB and / or HDMI terminals may include respective interface processors for connecting system 400 to other electronic devices via USB and / or HDMI connections. It should be understood that various aspects of the input processing, e.g., Reed-Solomon error correction, may be implemented, for example, within a separate input processing IC or within processor 410, as desired. Similarly, aspects of the USB or HDMI interface processing may be implemented, as desired, within a separate interface IC or within processor 410. The demodulated, error corrected, and demultiplexed stream is provided to various processing elements, including, for example, processor 410 and an encoder / decoder 430, which operates in combination with memory and storage elements to process the data stream as desired for presentation on an output device.

[0095] 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 suitable connection arrangements 425, such as internal buses as are known in the art, including Inter-IC (I2C) buses, wiring, and printed circuit boards.

[0096] 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.

[0097] In various embodiments, data is streamed or otherwise provided to system 400 using a wireless network such as a Wi-Fi network, e.g., IEEE 802.11 (IEEE, the Institute of Electrical and Electronics Engineers). The Wi-Fi signal in these examples 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. In other embodiments, streaming data is provided to system 400 using a set-top box that delivers data via an HDMI connection in input block 445. In yet other embodiments, streaming data is provided 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, such as a cellular network or a Bluetooth network.

[0098] System 400 can provide output signals to various output devices, including a display 475, speakers 485, and other peripheral devices 495. The display 475 of various embodiments includes, for example, one or more of a touchscreen display, an organic light-emitting diode (OLED) display, a curved display, and / or a foldable display. The display 475 may be for a television, a tablet, a laptop, a mobile phone, or other device. The display 475 may also be integrated with other components (e.g., as in a smartphone) or separate (e.g., an external monitor for a laptop). Other peripheral devices 495, in various examples of embodiments, include one or more of a standalone digital video disc (or digital versatile disc) (DVR, for both terms), a disc player, a stereo system, and / or a lighting system. Various embodiments use one or more peripheral devices 495 to provide functionality based on the output of system 400. For example, a disc player performs the function of playing the output of system 400.

[0099] In various embodiments, control signals are communicated between system 400 and display 475, speakers 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 speakers 485 may be integrated into a single unit with other components of system 400 within an electronic device such as a television. In various embodiments, display interface 470 includes a display driver, such as, for example, a timing controller (TCon) chip.

[0100] 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 where display 475 and speakers 485 are external components, the output signal may be provided via a dedicated output connection, including, for example, an HDMI port, a USB port, or a COMP output.

[0101] The embodiments may be executed by the processor 410, or by computer software implemented by hardware, or by a combination of hardware and software. As a non-limiting example, the embodiments may be implemented by one or more integrated circuits. The memory 420 may be of any type appropriate to the technology environment and may be implemented using any suitable data storage technology, such as, by way of non-limiting examples, optical memory devices, magnetic memory devices, semiconductor-based memory devices, fixed memory, and removable memory. The processor 410 may be of any type appropriate to the technology environment and may include, by way of 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.

[0102] Various implementations include decoding. As used herein, "decoding" may encompass all or part of the processes performed on a received encoded sequence to generate a final output suitable for, for example, a display. In various embodiments, such processes may include one or more of the processes typically performed by a decoder, such as entropy decoding, inverse quantization, inverse transform, and differential decoding. In various embodiments, such processes may also, or alternatively, include processes performed by the decoders of the various implementations described herein, such as receiving, decoding, and interpreting signals (e.g., as described herein) indicating elements, attributes, and metadata associated with point cloud components; identifying point cloud streams and their component substreams in a Media Presentation Descriptor (MPD); identifying the version of the point cloud and / or components of the point cloud; decoding the MPD to identify a main adaptation set and other adaptation sets and identify G-PCC components in Geometry-Based Point Cloud Compression (G-PCC) content; decoding the MPD to identify the main adaptation set and other adaptation sets and identify G-PCC components in Geometry-Based Point Cloud Compression (G-PCC) content; decoding the MPD to identify the adaptation sets or point cloud components in the representation; decoding the MPD to identify one or more versions of the G-PCC media; decoding the MPD to identify one or more G-PCC tile groups; decoding the MPD to identify one or more tile IDs of G-PCC components in the adaptation set; decoding the MPD to identify one or more characteristics of spatial regions and mappings between these regions and G-PCC tiles, characteristics of spatial regions and mappings between these regions and corresponding adaptation sets of G-PCC components, and / or mappings between spatial regions and corresponding adaptation sets of G-PCC components; decoding the MPD to identify timed metadata tracks for dynamic spatial regions, etc.

[0103] As a further embodiment, in one example, decoding may refer to entropy decoding, in another embodiment, decoding may refer to differential decoding, and in another embodiment, decoding may refer 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 a broader decoding process in general will be clear based on the context of the particular description and is believed to be well understood by those skilled in the art.

[0104] Various implementations may involve encoding. Similar to the above discussion regarding decoding, encoding as used herein may encompass all or part of the processes performed on an input video sequence to, for example, generate an encoded bitstream. In various embodiments, such processes include one or more of the processes typically performed by an encoder, such as, for example, partitioning, differential encoding, transforming, quantizing, and entropy encoding. In various embodiments, such processes may also, or alternatively, include processes performed by the encoder of the various implementations described herein, such as generating, encoding, and transmitting signals (e.g., as described herein) indicating elements, attributes, and metadata associated with point cloud components; encoding an MPD to indicate point cloud streams and component substreams of these point cloud streams; encoding an MPD to indicate a main adaptation set and other adaptation sets to support identification of geometry-based point cloud compression (G-PCC) components in G-PCC content; encoding an MPD to support identification of adaptation sets or types of point cloud components in the representation; encoding an MPD to indicate a main adaptation set and other adaptation sets; encoding an MPD to support identification of the type of point cloud component in the representation; to identify one or more preselections; encoding the MPD to support identification of one or more versions of G-PCC media; encoding the MPD to support identification of one or more G-PCC tile groups; encoding the MPD to support identification of one or more tile IDs of G-PCC components in an adaptation set; encoding the MPD to support identification of one or more characteristics of spatial regions and a mapping between these regions and G-PCC tiles, characteristics of spatial regions and a mapping between these regions and corresponding adaptation sets of G-PCC components, and / or a mapping between spatial regions and corresponding adaptation sets of G-PCC components; decoding the MPD to identify timed metadata tracks for dynamic spatial regions, etc.

[0105] As a further example, in one embodiment, encoding may refer to entropy encoding, in another embodiment, encoding may refer to differential encoding, and in another embodiment, encoding may refer 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 a broader encoding process in general will be clear based on the context of the particular description and is believed to be well understood by those skilled in the art.

[0106] It should be noted that the syntax elements used herein, such as those shown in Tables 1-23 and that may be otherwise shown in the discussion or figures presented herein, are descriptive terms and therefore do not preclude the use of other syntax element names.

[0107] Where a figure is presented as a flowchart, 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 flowchart of the corresponding method / process.

[0108] During the encoding process, a balance or trade-off between rate and distortion is typically considered, often subject to computational complexity constraints. Rate-distortion optimization is typically formulated to minimize a rate-distortion function, which is a weighted sum of rate and distortion. There are different approaches to solving the rate-distortion optimization problem. For example, these approaches may be based on extensive testing of all encoding options, including all considered modes or coding parameter values, with a thorough evaluation of their coding costs and the associated distortion of the reconstructed signal after encoding and decoding. To reduce the coding complexity, faster approaches may be used, particularly calculation of approximate distortion based on a prediction or prediction residual signal rather than the reconstructed signal. A mixture of these two approaches may be used, for example, by using approximate distortion for some of the possible encoding options and the full distortion for other encoding options. Other approaches may evaluate a subset of the possible encoding options. More generally, many approaches employ any of a variety of techniques to perform the optimization, but the optimization does not necessarily involve a thorough evaluation of both the coding cost and the associated distortion.

[0109] Implementations and aspects described herein may be implemented in, for example, a method or process, an apparatus, a software program, a data stream, or a signal. Even if discussed only in the context of a single implementation (e.g., discussed only as a method), the implementation of the discussed feature may also be implemented in other forms (e.g., an apparatus or a program). An apparatus may be implemented in, for example, appropriate hardware, software, and firmware. The method may be implemented in, for example, 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, for example, communication devices such as computers, mobile phones, handheld / personal digital assistants (PDAs), and other devices that facilitate communication of information between end users.

[0110] References to "one embodiment," "an embodiment," "an example," "one implementation," or "an implementation," and 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, appearances of the phrases "in one embodiment," "in an example," "in one implementation," or "in an implementation" in various places throughout this specification, as well as appearances of any other variations, do not necessarily all refer to the same embodiment or example.

[0111] 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 memory. Obtaining may include receiving, retrieving, constructing, generating, and / or determining.

[0112] 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.

[0113] 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 way, for example, storing information, processing information, transmitting information, moving information, copying information, erasing information, calculating information, determining information, predicting information, or estimating information.

[0114] 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 selection of only the first listed alternative (A), or selection of only the second listed alternative (B), or 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 phrases are intended to encompass selection of only the first listed alternative (A), or selection of only the second listed alternative (B), or selection of only the third listed alternative (C), or selection of only the first and second listed alternatives (A and B), or selection of only the first and third listed alternatives (A and C), or selection of only the second and third listed alternatives (B and C), or selection of all three alternatives (A and B and C). This can be expanded as many times as the number of listed items, as would be apparent to one of ordinary skill in this and related arts.

[0115] Also, as used herein, the term "signal" means, among other things, to indicate something to a corresponding decoder. For example, in some embodiments, an encoder signals (e.g., to a decoder) an MPD, an adaptation set, a representation, a preselection, a G-PCC component, a G-PCCComponent descriptor, a G-PCC descriptor or mandatory property descriptor, a supplemental property descriptor, a G-PCC tile inventory descriptor, a G-PCC static spatial region descriptor, a GPCCTileId descriptor, and a GPCC3DRegionID descriptor, among other descriptors, elements and attributes, metadata, schemas, etc. (e.g., as disclosed herein, including Tables 1-23). ​​In this way, in one embodiment, the same parameters can be used on both the encoder and decoder sides. Thus, for example, an encoder may send (explicitly signal) specific parameters to a decoder so that the decoder may use the same specific parameters. Conversely, if the decoder already has certain parameters as well as other parameters, signaling may be used without transmission (implicit signaling) to simply allow the decoder to know and select certain parameters. By avoiding transmitting any actual functionality, bit savings are realized in various embodiments. It should be understood that signaling may be achieved in various ways. For example, one or more syntax elements, flags, etc. are used in various embodiments to signal information to a corresponding decoder. Although the foregoing refers to the verb form of the word "signaling," the word "signal" may also be used as a noun herein.

[0116] As will be apparent to one skilled in the art, implementations may generate various 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 bitstream of the described embodiments. Such a signal may be formatted, for example, as an electromagnetic wave (e.g., using the 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 signal it carries may be, for example, analog or digital information. The signal may be transmitted over a variety of different wired or wireless links, as is known. The signal may be stored on a processor-readable medium.

[0117] A 3D point cloud may represent (e.g., be used to represent) immersive media. A point cloud may include a set of points represented in three-dimensional (3D) space. In embodiments, the points (e.g., each point) may be associated with one or more coordinates indicating the point's location and / or one or more attributes (e.g., point color, transparency, acquisition time, laser reflectivity, material properties, etc.). A point cloud may be captured or developed using, for example, one or more cameras, depth sensors, and / or light detection and ranging (LiDAR) laser scanners. A point cloud may include multiple points. In examples, the points (e.g., each point) may be represented by a set of coordinates (e.g., x, y, z coordinates) that map in 3D space. The points may be generated based on sampling of an object. In embodiments, the number of points in a point cloud may be on the order of millions or billions. The point cloud may be used to reconstruct one or more objects and / or scenes. Point clouds may be represented and / or compressed, for example, to store and / or transmit (e.g., efficiently store and / or transmit) point cloud data. Point cloud compression may support lossy and / or lossless coding (e.g., encoding or decoding) of geometric coordinates and / or attributes of point clouds. Point clouds may be deployed to support various applications (e.g., telepresence, virtual reality (VR), and / or large-scale dynamic 3D maps). In an embodiment, a library for mesh and point cloud compression may support compression of vertex positions, normals, colors, texture coordinates, and other general-purpose vertex attributes, for example, to improve the efficiency and speed of transmitting 3D content. An example of such a library is DRACO™, developed by GOOGLE™.

[0118] FIG. 5 illustrates an example bitstream structure for geometry-based point cloud compression (G-PCC). A G-PCC bitstream may include a set of G-PCC units, which may be referred to as a type-length-value (TLV) encapsulation structure, for example, as shown in FIG. 5. G-PCC and GPCC may be used interchangeably herein. As shown in FIG. 5, a G-PCC unit may include information about a G-PCC tlv_type and a G-PCC tlv unit payload. FIG. 5 illustrates various tlv unit payload types. Table 1 illustrates an example G-PCC TLV syntax. In an example, a G-PCC TLV unit (e.g., each G-PCC TLV unit) may include a TLV type, a G-PCC TLV unit payload length, and / or a G-PCC TLV unit payload. The TLV type (e.g., tlv_type shown in Table 1) may indicate a G-PCC unit type. Table 2 shows an example of TLV types (e.g., tlv_type shown in Table 1) and associated data unit descriptions. For example, a G-PCC TLV unit of unit type 2 may be a geometry data unit, and a G-PCC TLV unit of unit type 4 may be an attribute data unit. A point cloud may be reconstructed, for example, based on the geometry data unit and the attribute data unit. The geometry and / or attribute G-PCC unit payload may correspond to a media data unit (e.g., a TLV unit) that may be decoded by a G-PCC decoder. The geometry and attribute parameter set G-PCC unit may specify a G-PCC decoder for decoding the corresponding TLV unit. The G-PCC bitstream high-level syntax (HLS) may support slices and / or tile groups for geometry and attribute data. A frame may be divided into multiple tiles and slices. A slice may be a set of points that may be encoded or decoded (e.g., independently encoded or decoded). In an example, a slice may include a geometry data unit and zero or more attribute data units.An attribute data unit may depend on a corresponding geometry data unit, for example, within the same slice. Within a slice, a geometry data unit may appear before any associated attribute unit. The data units of a slice may be contiguous. The ordering of slices within a frame may not be specified. A group of slices may be identified by a common tile identifier. A tile inventory may be implemented that describes the bounding box of a tile (e.g., each tile). A tile may overlap another tile within its bounding box. Each slice may include an index that identifies which tile the slice belongs to. Table 1 shows an example of a G-PCC TLV encapsulation unit payload syntax, Table 2 shows an example of a G-PCC TLV type and data unit description, and Table 3 shows an example of a G-PCC TLV encapsulation unit payload syntax.

[0119] [Table 1]

[0120] [Table 2]

[0121] [Table 3] Examples of elements, attributes, syntax, and semantics are shown and described herein. Elements are distinguished from attributes. Attributes may be identified by an "@" preceding the attribute. Examples of element usage value ranges may be provided in the following format: <minimum> ... <maximum>, where the value of N may indicate that the value is unbounded. The elements, attributes, syntax, and semantics described herein are non-limiting examples that may or may not be implemented alone or in various combinations, with or without example usage, in various implementations.

[0122] A G-PCC container file format may be implemented. Figure 6 shows an example of a sample structure where the G-PCC geometry and attribute bitstreams may be stored in a single track. A video coding device may require, for example, that if the G-PCC bitstream is carried in a single track, that the G-PCC encoded bitstream be represented by a single track declaration. Single track encapsulation of G-PCC data may utilize simple encapsulation, such as ISO base media file format (ISOBMFF) encapsulation, by, for example, storing the G-PCC bitstream in a single track without further processing (e.g., further processing). A sample (e.g., each sample) in a single track (e.g., each sample in a track) may include one or more G-PCC components. Each sample may include one or more TLV encapsulation structures.

[0123] 7 shows an example of a multi-track (e.g., ISOBMFF) G-PCC container structure: the coded G-PCC geometry bitstream and the coded G-PCC attribute bitstream are stored in separate tracks, and each sample in a track may contain at least one TLV encapsulation structure carrying G-PCC component data.

[0124] A multi-track G-PCC ISOBMFF container may contain G-PCC tracks containing Geometry parameter sets, Sequence parameter sets, and / or geometry bitstream samples carrying geometry data TLV units. A G-PCC track may contain track references to other tracks carrying G-PCC attribute component payloads. A multi-track G-PCC ISOBMFF container may contain zero or more G-PCC tracks, each containing a respective attribute attribute parameter set and attribute bitstream samples carrying attribute data TLV units.

[0125] When a G-PCC bitstream is carried on multiple tracks, track referencing tools may be used to link between G-PCC component tracks. For example, TrackReferenceTypeBoxes may be added to a TrackReferenceBox within a TrackBox of a G-PCC track. The TrackReferenceTypeBox may contain, for example, an array of track_IDs that specify the tracks to which the G-PCC track references. To link a G-PCC geometry track to a G-PCC attribute track, the reference_type of the TrackReferenceTypeBox of the G-PCC geometry track may be implemented to identify the associated attribute track. The 4CC of the track reference type may be "gpca". In an embodiment, the referenced track may contain a coded bitstream of G-PCC attribute data.

[0126] If the geometry stream of a G-PCC bitstream contains multiple tiles, each tile or group of tiles may be encapsulated in a separate track, such as a geometry tile track. In an embodiment, the geometry tile track may carry one or more geometry tile TLV units, which may allow direct access to the tiles. The attribute stream of a G-PCC bitstream may contain multiple tiles and be carried in multiple attribute tile tracks.

[0127] G-PCC tile data may be carried in separate geometry and attribute tile tracks within the container. Partial access within the ISOBMFF container of a G-PCC coded stream may be supported. Tiles corresponding to spatial regions within a point cloud scene may be signaled in samples of timed metadata tracks, such as tracks with Dynamic3DSpatialRegionSampleEntry, or in GPCCSpatialRegionInfoBox boxes. This may enable a player and / or streaming client to retrieve a set of tile tracks that carry the information needed to render a particular spatial region or tile within a point cloud scene.

[0128] The G-PCC base track may carry a TLV encapsulation structure. The TLV encapsulation structure may include (e.g., may include only) a sequence parameter set (SPS), a geometry parameter set (GPS), an attribute parameter set (APS), and tile inventory information. To link the G-PCC base track to the geometry tile track, a track reference with a new track reference type may be defined using the four-character code (4CC) "gccg". The new type of track reference may be used to link the G-PCC base track with the geometry tile track (e.g., each of the geometry tile tracks).

[0129] A geometry tile track (e.g., each geometry tile track) can be linked to other attribute G-PCC tile tracks that carry attribute information for each tile or tile group using a track reference tool. The 4CC of these track reference types can be "gpca".

[0130] Alternate tracks may be indicated by an alternate track mechanism (e.g., the alternate_group field of the TrackHeaderBox). In an embodiment, G-PCC component tile tracks containing the same alternate_group value may be different coded versions of the same G-PCC component. Volumetric visual scenes may be coded as alternatives. In such a case, for example, G-PCC tracks that are alternatives to each other may contain the same alternate_group value in their TrackHeaderBoxes.

[0131] A G-PCC component tile track may contain alternatives. In such cases, G-PCC component tile tracks that belong to an alternative group (e.g., all G-PCC component tile tracks) may be referenced by the G-PCC base track and / or the respective G-PCC geometry tile track. In an embodiment, G-PCC component tile tracks that are alternatives to each other may use an alternative grouping mechanism.

[0132] MPEG Dynamic Adaptive Streaming over HTTP (MPEG-DASH), for example, is a delivery format that can dynamically adapt to changing network delivery conditions in order to provide an end user with a video experience (e.g., a better video experience).

[0133] Dynamic HTTP streaming may deliver multimedia content at one or more bit rates that may be available at a server. The multimedia content may include multiple media components (e.g., audio, video, and / or text media components). Different media components may include different characteristics. One or more characteristics of a media component may be described, for example, by a Media Presentation Description (MPD).

[0134] FIG. 8 shows an example MPD hierarchical data model. As shown in FIG. 8, an MPD may describe a sequence of periods (e.g., time intervals). For example, a set of encoded versions of a media content component may not change during a period. A period (e.g., each period) may have a start time and a duration associated with the period. A period (e.g., each period) may include one or more adaptation sets (e.g., an Adaptation Set, such as Adaptation Set 1 shown in FIG. 8). Adaptation Set, adaptation set, adaptationSet, and adaptationset may be used interchangeably herein. In an example, a DASH streaming client may be a WTRU, for example, as described herein with respect to FIGS. 1A-1D. In another example, a DASH streaming client may include a head-mounted device, a head-mounted projector, and / or a head-up display. In another example, a DASH streaming client may include a 3D television. In another example, a DASH streaming client may include one or more cameras (e.g., advanced cameras).

[0135] An adaptation set (e.g., an Adaptation Set, adaptation set, AdaptationSet, or adaptationset) may represent a set of coded versions of one or more media content components that share one or more properties (e.g., the same property), such as, for example, one or more of language, media type, picture aspect ratio, role, accessibility, viewpoint, rating property, etc. In an embodiment, an AdaptationSet may include different bitrates of geometry components and / or attribute components of multimedia content (e.g., G-PCC content). An AdaptationSet may include different bitrates of audio components (e.g., low-quality stereo and / or high-quality surround sound) of multimedia content (e.g., the same multimedia content). In an embodiment, an AdaptationSet (e.g., each Adaptation Set) may include multiple Representations.

[0136] A Representation may describe a deliverable encoded version of one or more media components. Representation and expression may be used interchangeably herein. A Representation may differ from other Representations by, for example, bit rate, resolution, number of channels, and / or other characteristics. A Representation (e.g., each Representation) may contain one or more segments. Attributes of a Representation element (e.g., @id, @bandwidth, @qualityRanking, and / or @dependencyId) may specify (e.g., may be used to specify) one or more properties of a Representation.

[0137] Segments can be retrieved using HTTP requests. Segments (e.g., each segment) can include a URL (e.g., an addressable location on a server). In an embodiment, segments can be downloaded using, for example, an HTTP GET or an HTTP GET with a byte range.

[0138] A DASH client may parse the MPD XML document. For example, the DASH client may select a collection of AdaptationSets (e.g., suitable for the DASH client's environment) based on, for example, the elements of the AdaptationSets (e.g., information provided in each of the elements of the AdaptationSets). The client may select a Representation of the AdaptationSets (e.g., within each AdaptationSet). The client may select a Representation based on, for example, the value of the @bandwidth attribute, client coding capabilities, and / or client rendering capabilities. The client may download an initialization segment of the selected Representation. The client may access the content (e.g., by requesting an entire segment or a byte range of a segment). The client may continue to consume media content, for example, when the presentation has started or during the presentation. The client may request (e.g., continuously request) media segments and / or portions of media segments during the presentation. The client may play the content according to the media presentation timeline. The client may switch from a first Representation to a second Representation based on, for example, updated information from the client's environment. A client may, for example, play content continuously over one or more Periods. A media presentation (e.g., being consumed by the client in a segment) may end, a Period may begin, and / or the MPD may be refetched, for example, towards the end of the announced media in the Representation.

[0139] MPEG-DASH descriptors may provide application-specific information about media content. Descriptor element structures may be similar. Descriptor elements may include, for example, an @schemeIdUri attribute, an @value attribute, and / or an @id attribute, which may provide a URI for identifying the scheme. Element semantics may be specific to the scheme employed. The URI identifying the scheme may be, for example, a URN or a URL. The MPD may provide information on how to use the element. Applications employing the DASH format may, for example, instantiate description elements using the scheme information. A DASH application using an element (e.g., a descriptor element) may define (e.g., initially define) a scheme identifier (e.g., in the form of a URI) and may define the value space of the element (e.g., for when the scheme identifier is used). In embodiments, extension elements and / or attributes may be defined, for example, in a separate namespace of structured data. Descriptors may appear at several levels within the MPD. For example, the presence of an element at the MPD level may indicate that the element is a child of an MPD element. For example, the presence of an element at the Adaptation Set level may indicate that this element is a child element of an AdaptationSet element. For example, the presence of an element at the Representation level may indicate that this element is a child element of a Representation element.

[0140] A bundle (e.g., in MPEG-DASH) may be a set of media components that can be jointly consumed by a decoder instance (e.g., a single decoder instance). A bundle (e.g., each bundle) may contain decoder-specific information and / or may contain a media component (e.g., a main media component) that can bootstrap a decoder. A PreSelection may, for example, reference, identify, and / or define a subset of media components in a bundle that can be jointly consumed (e.g., expected to be jointly consumed).

[0141] An Adaptation Set that includes a main media component may be referred to as a Main Adaptation Set. Main Adaptation Set, Main Adaptation Set, and Main Adaptation Set (e.g., any variation based on capitalization or composition of an adaptation set (e.g., adaptation set)) may be used interchangeably herein. A main media component may be included in a PreSelection that may be associated with a Bundle. A Bundle (e.g., each Bundle) may include one or more Partial Adaptation Sets. Partial Adaptation Sets may be processed in combination with the Main Adaptation Set.

[0142] Table 4 shows an example of PreSelection element semantics. A PreSelection may be defined, for example, through a PreSelection element, for example, as shown in Table 4. In an example, the selection of a PreSelection may be based on attributes and / or elements that may be included in the PreSelection element.

[0143] [Table 4] Multimedia applications such as virtual reality (VR) and immersive 3D graphics may be implemented using or represented by 3D point clouds, which may enable updated forms of interaction and / or communication with one or more virtual worlds. Static and dynamic point clouds may generate large amounts of information. Efficient encoding algorithms may be used to compress the point cloud information, for example, to reduce storage and / or transmission resource utilization by the point cloud information. For example, a bitstream of compressed dynamic point cloud information may utilize fewer transmission resources than a bitstream of uncompressed information.

[0144] A point cloud application may utilize coding, storage, and / or network resources (e.g., streaming point cloud data over a network). In embodiments, the point cloud application may perform live streaming or on-demand streaming of point cloud content, depending, for example, on how the content may be generated. The point cloud application may create, process, and / or transmit or receive large amounts of information representing the point cloud. The point cloud application may support adaptive streaming techniques, for example, to avoid network overload and / or to provide an optimized viewing experience, for example, with respect to varying network capacity and / or other operating conditions.

[0145] MPEG-DASH may provide (e.g., may be used to provide) adaptive delivery of point clouds. MPEG-DASH may be implemented, for example, using signaling to support point cloud media, including point cloud streams. The signaling elements may indicate or enable a streaming client to identify point cloud streams and component substreams of these point cloud streams within an MPD file. The signaling elements may indicate or enable a streaming client to identify one or more types of metadata that may be associated with point cloud components, for example, to enable a streaming client to select a version (e.g., best version) of a point cloud or point cloud component that the streaming client may be configured or configurable to support.

[0146] Components of the point cloud content may be available in different representations. In an embodiment, the multiple representations (e.g., each of the multiple representations) may represent a different quality level. A streaming client may utilize guidance regarding the different representations (e.g., instructions signaled in an MPD file). For example, the instructions may indicate which set of representations across different components constitutes a particular quality level (e.g., to perform graceful quality degradation). Components of the point cloud content may be divided into multiple tiles. A client may stream specific tile portions (e.g., selected tile portions) of a geometry component (e.g., instead of streaming all point cloud data) based on, for example, bandwidth availability. G-PCC component tile bitstreams may be available in different Adaptation Sets, e.g., an Adaptation Set (e.g., each Adaptation Set) may represent a G-PCC component tile.

[0147] G-PCC media content may include several components, such as geometry and / or attributes. A component (e.g., each component in a plurality of components) may be encoded separately, for example, as a substream of a G-PCC bitstream. Components such as geometry and attributes may be encoded, for example, using a G-PCC encoder. The substreams may be decoded together (e.g., along with metadata), for example, to render a point cloud.

[0148] The elements and / or attributes may be defined, for example, as XML elements and / or XML attributes. The XML elements may be defined, for example, within a separate namespace (e.g., "urn:mpeg:mpegI:gpcc:2020"). The namespace designator "gpcc:" may be used herein, for example, to refer to the separate namespace.

[0149] G-PCC Components may be signaled in a DASH MPD. In an embodiment, a G-PCC component (e.g., each G-PCC component) may be represented in a DASH manifest file (e.g., an MPD file) as a separate Adaptation Set, which may be referred to as a Component Adaptation Set, for example. An Adaptation Set containing geometry information may be a Main Adaptation Set, which may serve as an access point (e.g., a main access point) for G-PCC content, for example. In an embodiment, an adaptation set (e.g., one adaptation set) may be signaled per component per resolution. In an embodiment, the Main Adaptation Set may include an @codecs attribute set to "gpc1".

[0150] The EssentialProperty descriptor may be used with an @schemeIdUri attribute set equal to "urn:mpeg:mpegI:gpcc:2020:component" to identify, for example, the type of G-PCC component in a Component Adaptation Set. The EssentialProperty descriptor may be referred to, for example, as a GPCCComponent descriptor.

[0151] In an embodiment (e.g., at the adaptation set level), a GPCCComponent descriptor (e.g., one GPCCComponent descriptor) may be signaled for each point cloud component (e.g., each point cloud component) present in the Representation of the adaptation set.

[0152] Table 5 shows an example of elements and attributes of a GPCCComponent descriptor. In an example, the @value attribute of a GPCCComponent descriptor may not be present. The GPCCComponent descriptor may include the attributes defined in Table 5.

[0153] [Table 5] Table 6 shows an example of an XML schema for the GPCCComponent descriptor corresponding to Table 5.

[0154] [Table 6] The Main Adaptation Set may include, for example, an initialization segment at the adaptation set level (e.g., a single initialization segment) or multiple initialization segments at the representation level (e.g., one initialization segment for each representation). The initialization segment may include a G-PCC parameter set that may initialize (e.g., be used to initialize) a G-PCC decoder. The G-PCC parameter sets for one or more representations (e.g., all representations) may be included in the initialization segment, for example, if there is an initialization segment (e.g., a single initialization segment).

[0155] In an embodiment, the initialization segment of a Representation (e.g., each Representation) may include, for example, a G-PCC parameter set for the Representation and geometry data for the Representation if two or more Representations are signaled in the Main Adaptation Set. Representations of other Component Adaptation Sets (e.g., other Component Adaptation Sets of a point cloud) may list corresponding Representation identifiers from the Main Adaptation Set, for example, using the @dependencyId attribute. Representations in the Main Adaptation Set may be mapped to corresponding Representations in the G-PCC Component Adaptation Set. A media segment of a Representation in a Main Adaptation Set may include, for example, one or more track fragments of a G-PCC track. A media segment of a Representation in a Component Adaptation Set may include, for example, one or more track fragments of the corresponding component track (e.g., at the file format level).

[0156] In an embodiment, a Role descriptor element may be used with values ​​that may be defined for a G-PCC component. For example, one or more geometry components may include a corresponding value of gpcc-geometry, and / or one or more attribute components may include a corresponding value of gpcc-attribute. An EssentialProperty descriptor element (e.g., similar to the EssentialProperty descriptor element described for the example shown in Table 5) may be signaled at the adaptation set level. In an embodiment, an EssentialProperty descriptor element may be signaled (e.g., at the adaptation set level) excluding the component_type attribute. An EssentialProperty descriptor element may be signaled to identify, for example, a geometry component and / or an attribute component.

[0157] In an embodiment, for example, if multiple versions of a G-PCC component are encoded using different codecs, a version (e.g., each version) of the multiple versions of the G-PCC component may be signaled in a separate AdaptationSet with a value of the @codecs attribute set according to the media codec used. Switching (e.g., seamless switching) between Representations across AdaptationSets of multiple versions of a G-PCC component may be supported. Each of the multiple adaptation sets may include a SupplementalProperty descriptor with, for example, @schemeIdURI:mpeg:dash:adaptation-set-switching:2016 set to urn, and / or a @value containing a comma-separated list of AdaptationSet IDs corresponding to other available versions, to indicate that seamless switching between Representations across AdaptationSets of multiple versions of a G-PCC component is supported. In an embodiment, one or more rules for supporting switching across adaptation sets may be applied.

[0158] A G-PCC tile track may be signaled. When multiple tile tracks are present in a G-PCC container, the Main Adaptation Set may include (e.g., include only) the parameter set and tile inventory information from the G-PCC base track. Geometry data and / or attribute data may not be present in the Main Adaptation Set and its Representation. In an embodiment, the @codecs attribute of the Main Adaptation Set may be set to "gpcb," indicating, for example, that the Adaptation Set includes base track data including (e.g., include only) the SPS, GPS, APS, and Tile Inventory information of the G-PCC content.

[0159] A component tile track (e.g., each component tile track) may be signaled in a separate Adaptation Set. A separate Adaptation Set may be referred to as a Tile Component Adaptation Set. When multiple versions of a component of the same tile (e.g., or the same set of tiles) exist and are carried in separate tile tracks, each version may be signaled in a Representation of a Tile Component Adaptation Set. The @codecs attribute of a Tile Component Adaptation Set representing a component tile track of G-PCC media content may be set to "gpt1".

[0160] At the Tile Component Adaptation Set level, a GPCCComponent descriptor may be signaled. In an embodiment, the GPCCComponent descriptor may, for example, include an attribute (e.g., an additional attribute) @tile_ids indicating a list of tiles present in the tile bitstream. The GPCCComponent descriptor may include (e.g., conditionally include) an XML attribute @attr_index, for example, if the component represented by the containing Adaptation Set is a G-PCC attribute component. The @attr_index attribute may signal the order of G-PCC attribute components in the SPS and / or enable distinguishing between G-PCC attribute components, for example, if multiple G-PCC attribute components with the same attribute type (e.g., two or more color attributes) are present in the G-PCC content. A GPCCComponent descriptor present at the Tile Component Adaptation Set level may include elements and / or attributes defined in Table 7.

[0161] [Table 7] Table 8 shows an example of an XML schema for the GPCCComponent descriptor corresponding to Table 7.

[0162] [Table 8] In an embodiment, if multiple tile tracks are present in a container, each Representation in the geometry Tile Component Adaptation Set may reference a corresponding Representation in the Main Adaptation Set, for example, using the @dependencyId attribute. Each Representation in the attribute Tile Component Adaptation Set may reference a corresponding Representation in the geometry Tile Component Adaptation Set, for example, using the @dependencyId attribute.

[0163] G-PCC component tile tracks containing the same alternate_group value may be signaled in the MPD, for example, as a Representation of a Tile Component Adaptation Set.

[0164] A G-PCC descriptor may be signaled. A streaming client may identify (e.g., be able to identify or be configured to identify) the type of point cloud component in an AdaptationSet and / or Representation, for example, by checking the GPCCComponent descriptor in the corresponding element. A streaming client may distinguish between different geometry point cloud streams present in an MPD file.

[0165] A G-PCC descriptor may include, for example, a SupplementalProperty element with a @schemeIdUri attribute equal to urn:mpeg:mpegI:gpcc:2020:gpc". Table 9 shows an example of attributes of a G-PCC descriptor. In an example, one or more (e.g., at most one) G-PCC descriptors may be present at the adaptation set level of the Main Adaptation Set of the G-PCC media.

[0166] [Table 9] The data type of the attribute may be, for example, as defined in an XML schema. Table 10 shows an example of an XML schema for a G-PCC descriptor. The schema may be expressed as an XML schema with the namespace urn:mpeg:mpegI:gpcc:2020, for example.

[0167] [Table 10] A GPCCTileId descriptor may be signaled. A streaming client may identify one or more tile ids present in a G-PCC Tile Component AdaptationSet, for example, by checking a GPCCComponent descriptor. In an embodiment, one or more of the components of a G-PCC tile (e.g., all of the components) may be stored in a single track. For example, a GPCCComponent descriptor may not be signaled in the AdaptationSet associated with that track. In an embodiment, a streaming client may distinguish between different G-PCC tile tracks that may be present in an MPD file. For example, a streaming client may distinguish between different G-PCC tile tracks by identifying their respective tile streams.

[0168] In an embodiment, a SupplementalProperty element having a @schemeIdUri attribute equal to "urn:mpeg:mpegI:gpcc:2020:tileID" may be (e.g., may be referred to as) a GPCCTileId descriptor. The GPCCTileId descriptor may be used to distinguish between different G-PCC tile streams. In an embodiment, one (e.g., at most one) GPCCTileId descriptor may be signaled and / or present at the adaptation set level for G-PCC tiled media. One (e.g., at most one) GPCCTileId descriptor may be signaled or present at the adaptation set level, for example, if a GPCCComponent descriptor is not available at the adaptation set level (e.g., if all G-PCC component data for a tile or group of tiles is in one track).

[0169] In an embodiment, the @value attribute of the GPCCTileId descriptor may not be present. The GPCCTileId descriptor may include one or more attributes shown in Table 11.

[0170] [Table 11] The data types of the attributes may be as provided in an XML Schema. In an example, the XML Schema for the GPCCTileId descriptor may be as shown in the following example schema. This schema may be expressed as an XML Schema that includes the namespace urn:mpeg:mpegI:gpcc:2020, and may be specified as shown in Table 12 below.

[0171] [Table 12] G-PCC Preselection may be signaled. G-PCC preselection may be signaled in the MPD, for example, using a PreSelection element (e.g., defined in DASH), with an identifier (ID) list in the @preselectionComponents attribute including, for example, the ID of the Main Adaptation Set of the volumetric media and the ID of the AdaptationSet corresponding to the G-PCC component. In an embodiment, the @codecs attribute of the PreSelection may be set to "gpc1", which may indicate, for example, that the PreSelection media is a geometry-based point cloud. PreSelection may be signaled, for example, using a PreSelection element within a Period element and / or using a preselection descriptor at the adaptation set level.

[0172] Figure 9 shows an example of using preselection to group G-PCC components in an MPD. Figure 9 shows an example DASH configuration for grouping G-PCC components that may belong to volumetric media (e.g., a single volumetric media) in an MPEG-DASH MPD file.

[0173] Multiple versions of G-PCC media may be signaled. In an embodiment, multiple versions of the same point cloud media may be signaled, for example, using separate PreSelections. PreSelections representing alternative versions of the same geometry-based point cloud media may, for example, include G-PCC descriptors with the same @gpcId value. One or more (e.g., at most one) G-PCC descriptors may exist, for example, at the preselection level. A preselection may be a selectable alternative. The id list of the @preselectionComponents attribute may, for example, include the ID of the Main Adaptation Set, followed by the remaining component Adaptation Set IDs, if the @codecs attribute is set to "gpc1".

[0174] Figure 10 shows an example of using preselection to group multiple versions of a G-PCC component in an MPD. Figure 10 shows an example of a DASH configuration for grouping multiple versions of a G-PCC component that may belong to a single point cloud in an MPEG-DASH MPD file. The grouping / association may be signaled, for example, using a preselection descriptor. Table 13 shows an example of using preselection to signal multiple versions of a G-PCC component in an MPD.

[0175] [Table 13-1]

[0176] [Table 13-2]

[0177] [Table 13-3]

[0178] [Table 13-4]

[0179] [Table 13-5] In an embodiment, a G-PCC component AdaptationSet of a point cloud, or a Representation of an AdaptationSet, may list an identifier of the main AdaptationSet and / or Representation, e.g., using an @dependencyId attribute. For example, there may be a dependency (e.g., an inherent dependency) if segments in the main AdaptationSet are decoded together with segments from the point cloud component's AdaptationSet to reconstruct the point cloud.

[0180] In an embodiment, G-PCC Tile Preselection may be implemented. When G-PCC content is carried using multiple tile tracks, the Main Adaptation Set may signal G-PCC base track data. The Tile Component Adaptation Set may signal G-PCC geometry and / or attribute tile track data.

[0181] G-PCC Tile Preselection may be signaled in the MPD using the PreSelection element described herein. In an embodiment, the @codecs attribute of the Preselection may be set to "gpt1", for example, indicating that the Preselection media is a set of geometry-based point cloud tiles. Preselection may be signaled using a PreSelection element within a Period element, as described herein. Preselection may be signaled using a Preselection descriptor at the Tile Component Adaptation Set level.

[0182] The PreSelection element may contain a list of IDs for the @preselectionComponents attribute. The @preselectionComponents attribute ID list of the G-PCC Tile Preselection may contain a Tile Component Adaptation Set followed by the corresponding attribute Tile Component Adaptation Set ID. The Main Adaptation Set Representation corresponding to the selected geometry Tile Component Adaptation Set Representation may be identified, for example, using the @dependencyId attribute signaled in the Adaptation Set Representation.

[0183] A G-PCC Tile Preselection (e.g., each G-PCC Tile Preselection) may contain one or more GPCCTileId descriptors, which may enable identification of the tiles referenced in each preselection. If no GPCCTileId descriptor is present, the tiles belonging to the G-PCC Tile Preselection may be identified by finding the Geometry Tile Component Adaptation Set from the ID list of the @preselectionComponents attribute and checking the list of tile IDs from the GPCCComponent descriptors present in the Geometry Tile Component Adaptation Set.

[0184] FIG. 11 shows an example of G-PCC content with multiple tile tracks. FIG. 11 may be an exemplary DASH configuration. The G-PCC content may include a geometry component and one or more attribute components (e.g., three attribute components). In this example, the G-PCC bitstream includes six tiles grouped into two tile sets. The first tile set includes tiles 1, 2, and 3, and the second tile set includes tiles 4, 5, and 6. The components of each tile set may be available in two different versions (e.g., encoded at different qualities). The component versions of a tile set (e.g., each component version) may be carried in a separate G-PCC tile track within the ISOBMFF container file. The MPD file may include a Tile Component Adaptation Set for each component of the two tile sets. The Tile Component Adaptation Set (e.g., each Tile Component Adaptation Set) may include two representations (e.g., one for each version of the component). Two preselections may be used in the MPD to signal the two tile sets present in the G-PCC bitstream.

[0185] Table 14 shows an example of a DASH MPD file signaling G-PCC content with multiple tile tracks with a Preselection descriptor.

[0186] [Table 14-1]

[0187] [Table 14-2]

[0188] [Table 14-3]

[0189] [Table 14-4]

[0190] [Table 14-5] In an embodiment, media data may be signaled using separate PreSelections, e.g., if multiple point cloud media are available. A PreSelection representing geometry-based point cloud media data may include a G-PCC descriptor with a unique @gpcId value. One or more (e.g., at most one) G-PCC descriptors may be present, e.g., at the preselection level. There may be an ID of the main adaptation set, an ID (e.g., the first ID) in the list of adaptation set IDs in the @preselectionComponents attribute, and / or an ID of an AdaptationSet corresponding to (e.g., subsequent) point cloud components. The point cloud may be identified, e.g., using a unique value of the @gpcId attribute, as may be defined, e.g., within the G-PCC descriptor.

[0191] G-PCC tile groups may be signaled. In an embodiment, tile bounding box information may be signaled (e.g., using a GPCCTileInventory descriptor), for example, if there are multiple tiles in a geometry-based point cloud. The GPCCTileInventory descriptor may be, for example, a SupplementalProperty element with an @schemeIdUri attribute (e.g., set to "urn:mpeg:mpegI:gpcc:2020:gptl"). The GPCCTileInventory descriptor may be present, for example, at the adaptation set level of the Main Adaptation Set of G-PCC media if the G-PCC media is tiled. Table 15 shows an example of elements and attributes of a GPCCTileInventory descriptor.

[0192] [Table 15] Table 16 shows an example of an XML schema for the GPCCTileInventory descriptor. The data types of the various elements and attributes of the GPCCTileInventory descriptor may be defined according to an XML schema such as, for example, the example schema shown in Table 16.

[0193] [Table 16] A client may select (e.g., initially select) a tile ID from tile inventory bounding box information present in the MPD, for example, if the client is going to stream tiled G-PCC component data from a server. In an embodiment, the G-PCC component with the selected tile_id may be streamed to the client.

[0194] Dynamic G-PCC Tile Inventory information may be signaled. If parameter set data and / or tile inventory information are dynamically changing, information about such changes may be carried in samples of the G-PCC base track. In an embodiment, if there are multiple tiles in the geometry-based point cloud and the tile bounding box information is dynamically changing, the tile bounding box information (e.g., along with parameter set data) may be carried in the Media Segment of the Representation of the Main Adaptation Set.

[0195] A spatial region may be static. The characteristics of the spatial region and / or the mapping between the region and the G-PCC tile may be signaled (e.g., using a GPCC3DRegions descriptor), for example, if the 3D spatial region is static. A 3D spatial region may be static, for example, if the position and dimensions of the region (e.g., each region) do not change over presentation time. A GPCC3DRegions descriptor may be, for example, a SupplementalProperty element with an @schemeIdUri attribute equal to "urn:mpeg:mpegI:gpcc:2020:gpsr". A GPCC3DRegions descriptor (e.g., a single GPCC3DRegions descriptor) may be present, for example, at the adaptation set level and / or representation level in the main G-PCC track, or at the pre-selection level of geometry-based volumetric media content.

[0196] The @value attribute of the GPCC3DRegions descriptor may not be present. The GPCC3DRegions descriptor may include elements and / or attributes (e.g., as specified in Table 17). Table 17 shows example elements and attributes associated with the GPCC3DRegions descriptor.

[0197] [Table 17] The data types of the various elements and attributes of the GPCC3DRegions descriptor may be defined by a schema such as the XML schema shown in Table 18. Table 18 shows an example of an XML schema for the GPCC3DRegions descriptor.

[0198] [Table 18] In an embodiment, the properties of a spatial region and / or the mapping between the spatial region and the corresponding AdaptationSet of a G-PCC component may be signaled (e.g., using a GPCC3DRegions descriptor), e.g., when the 3D spatial region is static and tile inventory information is not available. The GPCC3DRegions descriptor may, for example, be a SupplementalProperty element with an @schemeIdUri attribute equal to "urn:mpeg:mpegI:gpcc:2020:gpsr". A GPCC3DRegions descriptor (e.g., a single GPCC3DRegions descriptor) may be present, for example, at the adaptation set level and / or representation level in the main G-PCC track, or at the pre-selection level for geometry-based volumetric media content.

[0199] The @value attribute of the GPCC3DRegions descriptor may not be present. The GPCC3DRegions descriptor may include elements and attributes (e.g., as specified in Table 19). Table 19 shows example elements and attributes of the GPCC3DRegions descriptor.

[0200] [Table 19] The data types of the various elements and attributes of the GPCC3DRegions descriptor may be defined according to a schema, such as an XML Schema. Table 20 shows an example of an XML Schema for the GPCC3DRegions descriptor.

[0201] [Table 20] In an embodiment, the mapping between a spatial region and a corresponding AdaptationSet of a G-PCC component may be signaled using a GPCC3DRegionId descriptor, for example, if the 3D spatial region is static. The descriptor may be a SupplementalProperty element with an @schemeIdUri attribute equal to "urn:mpeg:mpegI:gpcc:2020:gp3rid". A single GPCC3DRegionId descriptor may be present at the adaptation set level of a G-PCC component (e.g., each G-PCC component). A GPCC3DRegionId may not be present, for example, if a gpsr.spatialRegion@asIds attribute is present in the GPCC3DRegions descriptor.

[0202] The @value attribute of the GPCC3DRegionId descriptor may not be present. The GPCC3DRegionId descriptor may contain one or more attributes shown in Table 21.

[0203] [Table 21] The data type of the attribute may be as provided in an XML Schema. The XML Schema for the GPCC3DRegionID descriptor is shown below. This schema includes the namespace urn:mpeg:mpegI:gpcc:2020 and may be expressed as an XML Schema specified in Table 22.

[0204] [Table 22] In an embodiment, the mapping between a spatial domain and a corresponding AdaptationSet of a G-PCC component may be signaled using a GPCCComponents descriptor, e.g., if the 3D spatial domain is static. The GPCCComponent descriptor may include elements and attributes defined in Table 23. The GPCC3DRegionID descriptor may not be present, e.g., if the @region_Id attribute is present in the GPCCComponents descriptor.

[0205] [Table 23] An example of an XML schema for a GPCCComponent descriptor is shown in Table 24 below.

[0206] [Table 24] In an embodiment, one or more spatial regions may be dynamic. In the case of a 3D division that may be dynamic, timed metadata tracks for signaling the position and / or dimensions of the 3D regions (e.g., each 3D region) on the presentation timeline may be carried in a separate AdaptationSet with a single representation. The timed metadata tracks may be associated (e.g., linked) to the main G-PCC Adaptation Set. Attributes used may include an @associationId attribute and an @associationType value containing the 4CC "gpdr" of the corresponding AdaptationSet or Representation.

[0207] The streaming client behavior may be based on signaling, for example, signaling of one or more descriptors. A DASH client may be guided, for example, by information provided in an MPD. The following is an example client behavior for streaming geometry-based point cloud compressed content, for example, using the signaling examples disclosed herein. The example client behavior may assume, for example, that the association of component AdaptationSets to a main point cloud AdaptationSet is signaled using a G-PCC descriptor.

[0208] A streaming client may, for example, issue (e.g., initially issue) an HTTP request with a destination set to a content server. The streaming client may download an MPD file from the content server. The client may, for example, parse the MPD file to generate corresponding in-memory representations of the XML elements in the MPD file.

[0209] A streaming client may, for example, check the PreSelection element at the period level (e.g., with the @codecs attribute set to "gpc1" or "gpt1") to identify available G-PCC media content within the Period.

[0210] The AdaptationSets (e.g., all AdaptationSets) belonging to the point cloud content represented by a PreSelection element can be identified, for example, by checking the list of IDs in the @preselectionComponents attribute of the PreSelection. The Main Adaptation Set can contain an @id value equal to the @id value of the first ID in the list.

[0211] The streaming client can, for example, identify the number of unique point clouds by checking the G-PCC descriptor of the AdaptationSet and / or group AdaptationSets with the same @gpcId value in the G-PCC descriptor as versions of the same content.

[0212] The streaming client can identify the components of the point cloud (e.g., by checking the GPCCComponent descriptors of the remaining AdaptationSets referenced in the ID list of the @preselectionComponent attribute) and can map the components (e.g., each component) to its corresponding AdaptationSet. In an embodiment, more than one point cloud component may be present in an AdaptationSet.

[0213] A group of AdaptationSets having an @gpcId value present in the G-PCC descriptor corresponding to the desired content may be selected from the ID list of the @preselectionComponent attribute, for example, based on the point cloud content that the user may be interested in streaming. The streaming client may, for example, select an AdaptationSet group having a supported version (e.g., supported resolution) if there are multiple PreSelection descriptors with the same @gpcId value. For example, if there are no multiple PreSelection descriptors with the same @gpcId value, only one AdaptationSet group may be selected.

[0214] The client may start streaming the point cloud by, for example, downloading an initialization segment for the Main Adaptation Set, which contains a parameter set for initializing the G-PCC decoder. The initialization segments of the coded component streams may be downloaded and / or cached in memory.

[0215] The streaming client may begin downloading time-aligned media segments from the Main Adaptation Set and / or the component Adaptation Sets (e.g., in parallel via HTTP). In an embodiment, the downloaded segments may be stored in an in-memory segment buffer. The time-aligned media segments may be removed from their respective buffers and / or concatenated with their respective initialization segments.

[0216] A media container (e.g., ISO Base Media File Format (ISOBMFF)) can be parsed, for example, to extract elementary stream information and structure a G-PCC bitstream, which can be passed to a G-PCC decoder.

[0217] Client behavior for streaming G-PCC media with multiple tiles may be implemented using MPD signaling, for example, as described herein. A client (e.g., a streaming client) may issue an HTTP request and / or download an MPD file from a content server. The client may parse the MPD file to generate corresponding in-memory representations of the XML elements in the MPD file.

[0218] For example, a client can check for AdaptationSet elements with their @codecs attribute set to "gpcb" and PreSelection elements with their @codecs attribute set to "gpt1" at the period level to identify available G-PCC tiled media content within a Period.

[0219] If G-PCC tiled media content is present, the client may identify tiles of interest in the point cloud bitstream, for example, based on the client's current viewport. The client may parse the GPCC3DRegions descriptor and / or find each tile that is within the viewport. If the 3D division is dynamic, a timed metadata Adaptation Set Media Segment may be downloaded, which may convey the position and / or dimensions of the 3D region (e.g., each 3D spatial region) on the presentation timeline. The 3D region that is within the viewport may be identified. Each tile that belongs to the region may be identified.

[0220] If a tile of interest is found, the client may select a PreSelection element that has the tile, for example, by parsing the GPCCTileId descriptor present in the PreSelection element (e.g., each PreSelection element). The @tile_Ids attribute in the GPCCTileId descriptor may list the available tiles. The preselection element that has the tile of interest may be selected. The preselection (e.g., other Preselections) may be ignored.

[0221] If the GPCCTileId descriptor is not available, the tiles present in the PreSelection element can be identified, for example, by finding the Geometry Tile Component Adaptation Set from the id list of the @preselectionComponents attribute and finding the list of tile IDs from the GPCCComponent descriptors present in the Geometry Tile Component Adaptation Set. If the tile of interest is present in the PreSelection element, the Preselection can be selected by the client.

[0222] A group of Tile Component Adaptation Sets to be used to download a Media Segment from a selected Preselection may be identified from the ID list of the @preselectionComponent attribute. In an embodiment, the @preselectionComponents list may include geometry Tile Component Adaptation Set IDs. The @preselectionComponents list may include remaining component Tile Component Adaptation Set IDs. The ID of the Main Adaptation Set may not be present in the @preselectionComponents list. For example, the ID of the Main Adaptation Set may be identified using the @dependencyId attribute present in the Representation of the Geometry Tile Component Adaptation Set.

[0223] The client may start streaming the point cloud by, for example, downloading the Initialization Segment from the Main Adaptation Set, which may include a parameter set for initializing the G-PCC decoder.

[0224] The Initialization Segment for the coded component stream (eg, if present) may be downloaded and / or cached in memory.

[0225] A streaming client may download time-aligned Media Segments from geometry Tile Component Adaptation Sets and / or associated attribute Tile Component Adaptation Sets. The download may be parallelized over HTTP, and the downloaded segments may be stored in an in-memory segment buffer.

[0226] The time-aligned Media Segments may be removed from their respective buffers and / or concatenated with their respective Initialization Segments.

[0227] A media container (e.g., ISOBMFF) can be parsed, for example, to extract elementary stream information. The media container can be structured, and the resulting bitstream can be passed to a G-PCC decoder.

[0228] Many embodiments are described herein. Features of the embodiments may be provided alone or in any combination across various claim categories and types. Furthermore, an embodiment may include one or more of the features, devices, or aspects described herein, alone or in any combination across various claim categories and types, such as, for example, any of the following:

[0229] A decoder, such as exemplary decoder 300, configured to receive, decode, and interpret signals (e.g., as described herein) indicating elements, attributes, and metadata associated with point cloud components; identify point cloud streams and component sub-streams of these point cloud streams in a Media Presentation Descriptor (MPD); identify versions of the point cloud and / or components of this point cloud; decode the MPD to identify a main adaptation set and other adaptation sets and identify G-PCC components in Geometry-Based Point Cloud Compression (G-PCC) content; decode the MPD to identify adaptation sets or point cloud components in a representation; decoding the MPD to identify one or more versions of the G-PCC media; decoding the MPD to identify one or more G-PCC tile groups; decoding the MPD to identify one or more tile IDs of G-PCC components in the adaptation set; decoding the MPD to identify one or more characteristics of spatial regions and mappings between these regions and G-PCC tiles, characteristics of spatial regions and mappings between these regions and corresponding adaptation sets of G-PCC components, and / or mappings between spatial regions and corresponding adaptation sets of G-PCC components; decoding the MPD to identify timed metadata tracks for dynamic spatial regions, etc.

[0230] Decoding tools and techniques including one or more of entropy decoding, inverse quantization, inverse transform, and differential decoding used to enable the methods described herein in a decoder.

[0231] A decoder, such as exemplary decoder 200, configured to: generate, decode, and transmit signals (e.g., as described herein) indicating elements, attributes, and metadata associated with point cloud components; encode an MPD to indicate point cloud streams and component substreams of these point cloud streams; encode the MPD to indicate a main adaptation set and other adaptation sets to support identification of Geometry-Based Point Cloud Compression (G-PCC) components in G-PCC content; encode the MPD to support identification of adaptation sets or types of point cloud components in the representation; encode the MPD to indicate one or more preselection sets; encoding the MPD to support identification of one or more versions of G-PCC media; encoding the MPD to support identification of one or more G-PCC tile groups; encoding the MPD to support identification of one or more tile IDs of G-PCC components in an adaptation set; encoding the MPD to support identification of one or more characteristics of spatial regions and a mapping between these regions and G-PCC tiles, characteristics of spatial regions and a mapping between these regions and corresponding adaptation sets of G-PCC components, and / or a mapping between spatial regions and corresponding adaptation sets of G-PCC components; decoding the MPD to identify timed metadata tracks for dynamic spatial regions, etc.

[0232] Decoding tools and techniques, including one or more of entropy coding, inverse quantization, inverse transform, and differential coding, used in an encoder to enable the embodiments described herein.

[0233] For example, syntax elements inserted into signaling to allow a decoder to identify instructions associated with performing any of the embodiments described herein.

[0234] For example, syntax elements inserted into signaling to enable an encoder to generate or encode instructions associated with performing any of the embodiments described herein.

[0235] A bitstream or signal may include one or more of the described syntax elements or variations of these syntax elements associated with performing any of the embodiments described herein.

[0236] A method, process, apparatus, instruction storage medium, data storage medium, or signal, or variations thereof, for creating and / or transmitting and / or receiving and / or decoding a bitstream or signal including one or more of the described syntax elements.

[0237] A method, process, apparatus, instruction storage medium, data storage medium, or signal for creating and / or transmitting and / or receiving and / or decoding according to any of the embodiments described herein.

[0238] A TV, set-top box, mobile phone, tablet, or other electronic device that performs adaptive streaming of geometry-based point clouds, such as point cloud component sub-streams in a point cloud streaming service, according to any of the embodiments described herein.

[0239] A TV, set-top box, mobile phone, tablet, or other electronic device that performs adaptive streaming of geometry-based point clouds, such as point cloud component sub-streams in a point cloud streaming service, and displays the resulting images (e.g., using a monitor, screen, or other type of display) in accordance with any of the embodiments described herein.

[0240] A TV, set-top box, mobile phone, tablet, or other electronic device that selects (e.g., using a tuner) a channel for receiving a signal containing an encoded image, and performs adaptive streaming of a geometry-based point cloud, such as a point cloud component sub-stream in a point cloud streaming service, according to any of the embodiments described herein.

[0241] A TV, set-top box, mobile phone, tablet, or other electronic device that receives a signal containing an encoded image wirelessly (e.g., using an antenna) and performs adaptive streaming of geometry-based point clouds, such as point cloud component sub-streams in a point cloud streaming service, according to any of the embodiments described herein.

[0242] Although features and elements are described above in particular combinations, those 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. Furthermore, 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 via wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random-access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, 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.< / maximum> < / minimum>

Claims

1. A device, 1. A processor, comprising: receiving a Media Presentation Description (MPD) file from a content server; identifying a set of preselection elements from the MPD file; identifying one or more adaptation sets associated with at least one preselection element of the set of preselection elements, the one or more adaptation sets being indicated by an attribute associated with one of the preselection elements; determining a geometry-based point cloud compression (GPCC) tile identifier associated with a viewport, the GPCC tile identifier being determined based on a received first descriptor in the MPD file; selecting one or more adaptation sets associated with the GPCC tile identifier using a second descriptor; and requesting point cloud components associated with the one or more selected adaptation sets; receiving the point cloud component.

2. The device of claim 1 , wherein the processor is further configured to select, from the set of preselection elements, one or more preselection elements associated with the GPCC tile identifier.

3. The device of claim 2 , wherein the processor is further configured to select one or more adaptation sets associated with the selected one or more preselection elements.

4. The device of claim 1 , wherein the first descriptor is a three-dimensional (3D) region descriptor and the second descriptor is a component descriptor.

5. The device of claim 4 , wherein the component descriptor includes at least one of a component type, an attribute type, an index, or a set of tiles associated with a bitstream.

6. The device of claim 4 , wherein the 3D region descriptor includes at least one of a region location, one or more region dimensions, or a set of tiles associated with the 3D region.

7. The device of claim 1 , wherein each of the one or more adaptation sets includes one or more representations.

8. The device of claim 7 , wherein the one or more representations include at least one of a bit rate, a resolution, a number of channels, or a quality level.

9. 1. A method comprising: receiving a Media Presentation Description (MPD) file from a content server; identifying a set of preselection elements from the MPD file; identifying one or more adaptation sets associated with at least one preselection element of the set of preselection elements, the one or more adaptation sets being indicated by an attribute associated with one of the preselection elements; determining a geometry-based point cloud compression (GPCC) tile identifier associated with a viewport, the GPCC tile identifier being determined based on a received first descriptor in the MPD file; using a second descriptor to select one or more adaptation sets associated with the GPCC tile identifier; and requesting point cloud components associated with the one or more selected adaptive sets; and receiving the point cloud component.

10. The method of claim 9 , further comprising selecting, from the set of preselection elements, one or more preselection elements associated with the GPCC tile identifier.

11. The method of claim 10 , further comprising selecting one or more adaptation sets associated with the selected one or more preselection elements.

12. The method of claim 9 , wherein the first descriptor is a three-dimensional (3D) region descriptor and the second descriptor is a component descriptor.

13. The method of claim 12 , wherein the component descriptor includes at least one of a component type, an attribute type, an index, or a set of tiles associated with a bitstream.

14. The method of claim 12 , wherein the 3D region descriptor comprises at least one of a region location, one or more region dimensions, or a set of tiles associated with the 3D region.

15. The method of claim 9 , wherein each of the one or more adaptation sets includes one or more representations.

16. The method of claim 15 , wherein the one or more representations include at least one of a bit rate, a resolution, a number of channels, or a quality level.

17. The method of claim 9 , comprising selecting one or more preselection elements from the set of preselection elements that represent multiple point cloud streams.

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