RENDERING STRATEGY BASED ON USER DATA CONFIDENCE LEVEL

Abstract

Systems and methods for rendering XR content based on the confidence level of tracked XR data. One method according to some modalities comprises: obtaining at least a first tracked parameter (e.g., XR data such as pose, gesture, or gaze information, among other possibilities) and a first confidence level associated with the first tracked parameter; determining whether the first confidence level is below a first threshold associated with the first tracked parameter; and for at least one current frame of an extended reality presentation, in response to the determination that the first confidence level is below the first threshold, performing a first default rendering action associated with the first tracked parameter.The possible default actions are specified in a set of strategies, defined for each XR data type and rendering type and sent to the presentation engines in the configuration of an XR application.

Description

RENDERING STRATEGY BASED ON CONFIDENCE LEVEL OF USER DATACROSS-REFERENCE

[0001] This application claims the priority of European Patent Application No. 23306732.1 , filed 9 October 2023, entitled “Rendering Strategy Based on Confidence Level of User Data,” which is incorporated herein by reference in its entirety.BACKGROUND

[0002] The 3GPP specification defines several architectures for an Extended Reality (XR) applications / service. Different modules are specified that provides to a user an XR experience through its User Equipment (UE). An XR runtime module provides to the other modules a set of functionalities such as composition, peripheral management, tracking, and spatial localization. A presentation engine renders and provides frames of different types. One type of frame is a visual frame to be displayed on the UE display (visual renderer). A second type of frame is an audio frame to be sent to the UE speaker(s) (audio renderer). A third type of frame is a haptic frame to feed the UE actuator(s) (haptic renderer). Additional modules include a Scene Manager and Media Access functions.

[0003] The XR runtime and the presentation engine may be on the same device (standalone device, as in FIG. 1 , or they may be on two remote devices (for instance in a cloud or Edge based / split rendering architecture as in FIG. 2).

[0004] In an XR application, the quality of the visual and audio rendering of an XR scene, depends on the XR data, which may be described as information from the user, the UE and the user’s environment. This information may include the user / UE pose (view pose), the gaze direction, a trackable pose, a user input, a hand / body gesture, camera information, and the like. These XR data may be generated from a set of sensors and are provided by the XR Runtime module to the presentation engine that renders and provides visual, audio or haptic frames.

[0005] Open XR, an application Programming Interface (API) for XR applications, provides a set of functions or extensions, to access different types of XR data. These functions include the following functions, among others:• xrLocateViews() to retrieve the viewer pose.• xrLocateSpace() to retrieve the trackable pose.• XR_EXT_hand_tracking and XR_FB_body_tracking extensions to detect hand and body position and gesture.• XR_FB_eye_tracking_social to obtain the position and orientation of the user’s eyes.

[0006] A typical call flow in an XR application is given in the 3GPP SR_MSE TS 26.565 specification and is shown in FIG. 3. The call flow may be described with reference to two main phases. The first phase is the setup of the XR session: split rendering and connection setup, and XR runtime configuration. During this phase, the UE and the split rendering server (SRS) exchange information on XR space, user actions, view configuration, and projection format. The second phase is the rendering loop, scheduled at a predefined frame rate, which includes the transmission of the XR data (pose information and user actions in the SR_MSE case) from the XR Runtime to the SRS and the transmission of the rendered frames from the SRS to the XR Runtime.SUMMARY

[0007] A method according to some embodiments comprises: obtaining at least a first tracked parameter (e.g. XR data such as pose, gesture, or gaze information, among other possibilities) and a first confidence level associated with the first tracked parameter; determining whether the first confidence level is below a first threshold associated with the first tracked parameter; and for at least one current frame of an extended reality presentation, in response to a determination that the first confidence level is below the first threshold, performing a predetermined first rendering action associated with the first tracked parameter.

[0008] In some embodiments, the predetermined first rendering action is at least one of: rendering the current frame using a most-recent value of the tracked parameter associated with a confidence level that is not below the first threshold; presenting a most-recently- rendered frame in place of the current frame; presenting a still image in place of the current frame; or presenting a fade-out effect. Other actions may be used as alternatives or in addition to these.

[0009] In some embodiments, the first tracked parameter is at least one of: a user pose; a user gaze direction; a pose of a trackable; a description of a user input; or a description of a user gesture.

[0010] In some embodiments, the method is performed by a client device in a standalone rendering architecture. In other embodiments, the method is performed by a split rendering server in a split rendering architecture.

[0011] When the method is performed by a split rendering server, in some embodiments, the method further includes receiving, from a client device in the split rendering architecture, data associating the first tracked parameter, the first threshold, and the first rendering action. Such data may be received during a setup process of an extended reality session. In some embodiments, such data may be received in a data object, such as one or more of the strategy objects with a syntax as provided herein.

[0012] Some embodiments further include receiving a plurality of data objects during the setup process, each data object associating a respective tracked parameter with at least one respective threshold and at least one respective rendering action. In some embodiments, a plurality of thresholds are provided in an array, an a plurality of rendering actions are identified in a corresponding array, with each threshold corresponding to a respective one of the rendering actions.

[0013] In some embodiments, the plurality of data objects include respective identifiers to distinguish different data objects associated with the same tracked parameter.

[0014] In some embodiments, the plurality of data objects include respective priority indicators, and wherein a determination of a rendering action is based at least in part on the priority indicators.

[0015] In some embodiments, the plurality of data objects include respective rendering type indicators, wherein the rendering type indicator indicates at least one of: audio rendering, visual rendering, or haptics rendering. The specified rendering action may affect only the identified type of rendering.

[0016] An apparatus according to some embodiments comprises one or more processors configured to perform at least: obtaining at least a first tracked parameter and a first confidence level associated with the first tracked parameter; determining whether the first confidence level is below a first threshold associated with the first tracked parameter; for at least one current frame of an extended reality presentation, based at least in part on a determination that the first confidence level is not below the first threshold, rendering the current frame based on the first tracked parameter; and for the current frame, in response to a determination that the first confidence level is below the first threshold, performing a predetermined first rendering action associated with the first tracked parameter.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 illustrates an XR standalone architecture.

[0018] FIG. 2 illustrates an XR split rendering architecture.

[0019] FIG. 3 illustrates a conventional high-level call flow for split rendering session setup and operation.

[0020] FIG. 4 illustrates a call flow according to an example embodiment using rendering strategy management based on confidence of tracked data.

[0021] FIG. 5 is a flow diagram of a rendering method performed in some embodiments.

[0022] FIG. 6 is a functional block diagram of an apparatus that may be used to implement a client and / or server in some embodiments.DETAILED DESCRIPTION

[0023] For cloud or edge-based rendering as in FIG. 3, predictions (for instance pose prediction) are used to compensate for the round-trip time needed to render the virtual scene through the rendering loop. Those predicted XR data are calculated by the UE (e.g., by extrapolating past poses values) and sent to the split rendering server (SRS). They may also be calculated by the SRS from XR raw data (sensors output and / or flags from the XR runtime module), sent by the UE. Those predicted XR data may be subject to low accuracy level.

[0024] As seen in FIG. 3, at 301 , a split rendering client creates a split rendering session with a split rendering server. At 302, a description of the split rendering output is sent to the scene manager of the split rendering client. At 303, transport connections such as a WebRTC session are established between the scene manager and the split rendering server. In a rendering loop, at 304, pose information and user actions from an XR runtime are received at 304 (e.g. by an XR source management module) and provided to the split rendering server at 305. At 306, the split rendering server performs rendering for the requested pose. At 307, the split rendering server sends the next buffer frame to a media access function of the split rendering client. At 308, the media access function decodes and processes the buffer frame. At 309, the media access function passes raw buffer frames for display to the XR runtime, which composes and renders the frames at 310.

[0025] However, even in a standalone architecture where the round-trip time is not an issue, the quality of the sensors, the lighting condition may lead to inaccurate calculated / measured XR data (for instance the detection and the tracking of a trackable). This low accuracy of XR data, predicted or not, may be expressed by a confidence level, calculated by the UE, and sent to the presentation engine along with the XR data.

[0026] For example, the pose prediction confidence level may affect the rendering quality, and knowledge of this confidence level may be used to improve the quality of experience (QoE). The pose confidence level may be estimated and sent to the presentation engine alongwith the pose prediction. More generally, a confidence level may be estimated for each of the many other XR data that feed the rendering process and thus impact the QoE.

[0027] In the 3GPP SR_MSE TS 26.565 specification, a set of XR data are specified that are sent to the presentation engine (pose and user action). Embodiments described herein relate to the determination and use of confidence level information relating to various different types of this XR data. Further embodiments address the confidence level of other types of XR data that are not yet addressed in this invention may be specified in a future version of this document. Example embodiments further describe methods implemented by a presentation engine to make an appropriate decision if the confidence levels for one or more XR data are too low.

[0028] Example embodiments include actions that may be used by the presentation engine to render the appropriate frames depending on the confidence level of the XR data. In some embodiments, information characterizing these methods may be sent to the presentation engine during the setup of the XR session. During the rendering loop, the presentation engine checks the XR data and their confidence levels and makes rendering decisions according to the appropriate action.

[0029] With regard to a confidence level of the pose prediction, threshold may be defined for each type of XR data that trigger different kinds of decision in case the confidence level is below the threshold. For visual rendering, one of the following actions may be taken in response to a determination of a confidence level below the threshold:• Providing the last rendered image.• Rendering an image from the last correct XR data (with a confidence level above the threshold). This action may be used to consider some modifications of the 3D scene that may have occurred independently from the XR data (such as animated 3D objects, physics simulations, and the like).• Providing a still image displaying for instance a message for the user.

[0030] For audio rendering, one of the following actions may be taken in response to a determination of a confidence level below the threshold:• Rendering an audio frame from the last correct XR data (with a confidence level above the threshold).• Initiating the rendering of a series of audio frames until the confidence value reaches a correct value, for instance to create a fading out effect before muting the sound, or to create a non-spatial version of the original audio content.

[0031] For haptic rendering, one of the following actions may be taken in response to a determination of a confidence level below the threshold:• Rendering a haptic frame from the last correct XR data (with a confidence level above the threshold).• Initiating the rendering of a series of haptic frames until the confidence value returns to a correct value, for instance to create a fading out effect before stopping the haptic effect, or to create a non-directional version of the original haptic content.

[0032] In example embodiments, the presentation engine is configured with information indicating which action to perform based on the confidence level of the XR data. In a standalone architecture, the action(s) may be set by the AR / MR application, at the loading of the scene. In a cloud or edge-based architecture, the action(s) may be negotiated during the setup of the session between the UE and the server, for example during a split rendering session setup. The information indicating the action(s) to be performed may be included in the XR runtime configuration data transmitted during the split rendering session creation.

[0033] FIG. 4 illustrates a call flow diagram of a rendering method that may be performed in some embodiments. In step 401 , the creation of a split rendering session includes providing XR configuring information including information identifying actions (or “strategies”) to be implemented in the case of a low confidence level for XR data. At 402, a description of the split rendering output is sent to the scene manager of the split rendering client. At 403, transport connections such as a WebRTC session are established between the scene manager and the split rendering server. At 404 and 405, the transmission of pose information, user actions, and other XR data is performed, including information regarding the confidence level of the data. In some embodiments, the XR data may be provided with a unique id to distinguish between several XR data of the same type, such as multiple trackables in the scene, multiple user gestures, and the like. At 406, the split rendering server performs rendering for the requested pose based on rendering strategies with respect to the XR data and the confidence levels of that data. At 407, the split rendering server sends the next buffer frame(s) to the media access function of the split rendering client. At 408, the media access function decodes and processes the buffer frame. At 409, the media access function passes raw buffer frames for display to the XR runtime, which composes and renders the frames at 410.

[0034] Example embodiments define methods to be performed by a renderer when the confidence level for an XR data is below a threshold. If the confidence level is above thethreshold, the XR data is considered good enough to be used for the computation of a new frame.

[0035] The following are examples of actions that may be performed in response to a determination that one or more parameters of XR data has a confidence level below a threshold. The following list uses examples relating to audio, visual and haptic rendering, but the listed actions may be used for other types of rendering as well.• USE LAST DATA (for audio, visual and haptics rendering): The last value of the XR data with a correct confidence level is used to render a new frame. The correct XR data is kept by the presentation engine for later use.• USE LAST FRAME (for visual rendering): The last visual frame that was correctly rendered is used, even if some other XR data have a correct confidence level. Each time a frame is rendered from a correct set of XR data, and this frame is stored by the presentation engine for later use.• USE STILL FRAME (for visual rendering): A still image is provided, which may optionally display a message for the user. In some embodiments, the still image may be accompanied by a mute audio frame. In some cases, hints on how to improve the erroneous XR data may be presented (via audio and / or video). A hint may provide a suggestion to move more slowly, or to increase or decrease lighting intensity, for example. In some cases, a waiting message may be presented to the user.• USE_FADING_FRAME (for visual, audio, and haptic rendering): Initiate the rendering of a series of fading out frames until the confidence level returns to a correct value.This series may start, for instance, from the rendered frame related to the last correct XR data. When the confidence level reaches back a correct value, a new frame is rendered using the correct XR data.

[0036] In some cases, one action may be implemented globally for all the XR data. In some cases, one or more actions may be applied for each type of XR data.

[0037] In some embodiments, the data used to configure the renderer on the handling of low confidence levels is provided in the form of an array of “strategy” objects. In one example, each strategy object contains the type of a renderer, the type of the XR data, a data id, a threshold value, and information indicating an action to implement. The syntax of an example strategy object is shown in Table 1 .Table 1.

[0038] In Table 1 and other syntax examples described herein an indication that a syntax element is “mandatory” or “optional” only indicates whether it is mandatory or optional according to the syntax rules of that particular embodiment. A “mandatory” syntax element in one embodiment may be optional or even omitted entirely in a different embodiment.

[0039] The syntax elements of the strategy objects of Table 1 may convey the following information. render_type'. The type of Tenderer that is targeted by the strategy object:• ALL,• VISUAL,• AUDIO,• HAPTIC• [other]

[0040] If this parameter set to ALL or if it is absent, the strategy object is applied to all the Tenderers. datatype’, the type of XR data for which the action is implemented. For instance, it may have the following possible values:• ALL,• VIEW POSE for the user / UE pose,• GAZE POSE for the gaze direction,• TRACKABLE POSE for the pose of a trackable,• USER ACTION for user input,• GESTURE POSE for the description of a user hand / body gesture,• Any other values that identify additional XR data.

[0041] If this parameter is set to ALL, or if it is absent, an action is selected that can be applied to all the XR data types. datajd'. A unique id of an XR data. Multiple elements of an XR scene may produce XR data of the same type (multiple trackables in the scene, multiple user gestures, etc.). And those XR data may have different actions defined by different strategy objects. If this parameter is absent, the strategy object is applied to all objects of the same datatype. This id corresponds to the id that is sent by the XR runtime, during the rendering loop, along with each XR data. threshold’, a confidence level value under which (under or equal) a level is considered invalid. The confidence level may be a float number between 0 and 1. In some embodiments, it may have a finite number of possible values (e.g. 0, 1 / 8, 2 / 8 ,7 / 8,1). decision', the action to apply that may have the following value as described above:• USE LAST DATA,• USE LAST FRAME,• USE STILL FRAME,• USE_FADING_FRAME,• [other]

[0042] In some embodiments, several strategy objects may be specified for a given XR data. This may be done, for example, by defining different threshold values corresponding to different rendering decisions. For example, the xr strategies array may include a strategy object that employs USE STILL FRAME for confidence level lower that 2 / 8 and another strategy object that employs USE LAST DATA for confidence level lower than 5 / 8 (i.e., between 2 / 8 and 5 / 8). If the confidence level is higher than 5 / 8, the XR data is considered valid for the processing of a new rendered image.

[0043] The following is an example of an array of strategy objects using a JSON syntax, although different syntaxes may be used in different embodiments."xr strategies": [”{"render type": "VISUAL","data type": "POSE","data id": 0, "threshold": 0.2, "decision": "USE_STILL_FRAME"} ,{"render type": "VISUAL","data type": "POSE","data id": 0, "threshold": 0.5, "decision": "USE_LAST_DATA"} ,{"render type": "VISUAL", "data_type": "GESTURE", "data id": 1, "threshold": 0.5,"decision": "USE_LAST_FRAME " } , {"render type": "AUDIO", "data_type": "GESTURE", "data id": 1, "threshold": 0.5,"decision": "USE_LAST_FRAME " } , {"render type": "HAPTIC", "data_type": "GESTURE", "data id": 1,"threshold": 0.5,"decision": "USE FADING FRAME"

[0044] In some embodiments, the one or more actions are described in an array of strategy objects (e.g., with only one object for each XR data type), containing the type of the XR data, a list of threshold values, and a list of corresponding actions to apply. It improves the implementation of several strategies for one XR data.Table 2.

[0045] The syntax elements of the strategy objects of Table 2 may convey the following information. render_type, data_type and data_id'. same parameters as described above. thresholds: an array of threshold value to consider for the above data_type, as specified above. decisions', an array of values indicating actions to be performed, each action corresponding to the threshold value of the same index in the threshold array.

[0046] The following is an example of a strategy object description using the syntax elements of Table 2, implemented using a JSON syntax:"xr strategies": [”{"render type": "VISUAL","data type": "POSE","data id": 0,"thresholds": [0.2, 0.5]"decisions": [ "USE_STILL_FRAME" , "USE_LAST_DATA" ]} ,{"render type": "VISUAL","data_type": "GESTURE","data id": 0,"thresholds " : [0.5] ,"decisions " : [ "USE_LAST_FRAME " ]

[0047] In example embodiments, when the presentation engine receives the set of XR data and their confidence level, it determines whether the confidence level is below a threshold, and, in response to a determination that the confidence level is below the threshold, the presentation engine renders a frame according to the indicated action.

[0048] There may be cases in which inconsistent actions are both triggered based on low confidence levels (e.g., USE LAST DATA and USE LAST FRAME). In some embodiments, such a situation may be resolved by implementing a default action, such as a USE LAST FRAME action. In some embodiments, different actions may be assigned different priorities, either by default or through configuration, and the situation may be resolved by implementing the triggered action with the higher priority. In some embodiments, the priority may be expressed by an extra parameter (e.g., priority) in a strategy object, set to a value between 0 (low priority) and 5 (high priority). The absence of this parameter in a strategy object may indicate a low priority. The following is an example of a strategy object description implementing the priority parameter, using a JSON syntax.{"xr strategies": [”{"render type": "VISUAL","data_type": "VIEW_POSE","data id": 0,"threshold": 0.2,"decision": "USE_LAST_FRAME " , "priority": 5} ,{"render type": "VISUAL","data_type" : "TRACKABLE_POSE" ,"data id": 0,"threshold": 0.5,"decision": "USE_LAST_DATA" , "priority": 2} ,{"render type": " VISUAL ","data_type": "GESTURE_POSE" ,"data id" : 1 , "threshold" : 0 . 5 , "decision" : "USE_LAST_FRAME " }] }

[0049] FIG. 5 is a flow chart of a method performed in some embodiments. In some embodiments, the method of FIG. 5 is performed by a split rendering server. In such cases, the method of FIG. 5 may be understood in some embodiments to take place after a setup process has occurred in which strategy objects (or similar data in other forms) have been received from the client. In other embodiments, the method of FIG. 5 is performed by the client itself.

[0050] As shown in FIG. 5, during runtime, information is obtained at 502, 504 regarding different types of tracked XR data and the confidence level of that data. For those types of tracked data that are associated with a predetermined threshold, the confidence levels are compared to the respective thresholds to identify at 506 any types of tracked data with a confidence level below the threshold. If there are none, then rendering of an XR frame may be performed at 509 as usual. The rendered frame may be stored at 51 1 for later use in case one of the confidence levels falls below its corresponding threshold in a future frame.

[0051] If one or more of the confidence levels falls below the corresponding threshold as determined at 506, the rendering actions associated with those thresholds are identified at 508. If none of the identified rendering actions are incompatible with one another, then all such actions may be implemented. If some actions are incompatible (e.g. displaying a prior frame versus displaying a new frame using previous tracked data), then a determination may be made of which rendering action to perform. The determination may be made based on priority data (e.g. from a strategy object) as shown at 510 or otherwise, e.g. an action associated with a lower confidence level may be given priority over an action associated with a higher confidence level. Based on the determination, the one or more selected rendering actions is performed. Actions performed may be, for example, implementing a fade effect (512), rendering a new frame using prior tracked data (514), displaying a still image such as a notification or recommendation to the user (516), or displaying a frame that was previously rendered (518).Example Systems

[0052] The encoding, decoding, processing, and rendering of XR content as described herein may be implemented using a system such as the system of FIG. 6. FIG. 6 is a block diagramof an example of a system in which various aspects and embodiments are implemented. System 1000 can be embodied as a device including the various components described below and is configured to perform one or more of the aspects described in this document. Examples of such devices, include, but are not limited to, various electronic devices such as personal computers, laptop computers, smartphones, tablet computers, digital multimedia set top boxes, digital television receivers, personal video recording systems, connected home appliances, and servers. Elements of system 1000, singly or in combination, can be embodied in a single integrated circuit (IC), multiple ICs, and / or discrete components. For example, in at least one embodiment, the processing and encoder / decoder elements of system 1000 are distributed across multiple ICs and / or discrete components. In various embodiments, the system 1000 is communicatively coupled to one or more other systems, or other electronic devices, via, for example, a communications bus or through dedicated input and / or output ports. In various embodiments, the system 1000 is configured to implement one or more of the aspects described in this document.

[0053] The system 1000 includes at least one processor 1010 configured to execute instructions loaded therein for implementing, for example, the various aspects described in this document. Processor 1010 can include embedded memory, input output interface, and various other circuitries as known in the art. The system 1000 includes at least one memory 1020 (e.g., a volatile memory device, and / or a non-volatile memory device). System 1000 includes a storage device 1040, which can include non-volatile memory and / or volatile memory, including, but not limited to, Electrically Erasable Programmable Read-Only Memory (EEPROM), Read-Only Memory (ROM), Programmable Read-Only Memory (PROM), Random Access Memory (RAM), Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM), flash, magnetic disk drive, and / or optical disk drive. The storage device 1040 can include an internal storage device, an attached storage device (including detachable and non-detachable storage devices), and / or a network accessible storage device, as non-limiting examples.

[0054] System 1000 includes an encoder / decoder module 1030 configured, for example, to process data to provide an encoded scene or decoded scene, and the encoder / decoder module 1030 can include its own processor and memory. The encoder / decoder module 1030 represents module(s) that can be included in a device to perform the encoding and / or decoding functions. As is known, a device can include one or both of the encoding and decoding modules. Additionally, encoder / decoder module 1030 can be implemented as a separate element of system 1000 or can be incorporated within processor 1010 as a combination of hardware and software as known to those skilled in the art.

[0055] Program code to be loaded onto processor 1010 or encoder / decoder 1030 to perform the various aspects described in this document can be stored in storage device 1040 and subsequently loaded onto memory 1020 for execution by processor 1010. In accordance with various embodiments, one or more of processor 1010, memory 1020, storage device 1040, and encoder / decoder module 1030 can store one or more of various items during the performance of the processes described in this document. Such stored items can include, but are not limited to, the input scene, the decoded scene or portions of the decoded scene, the bitstream, matrices, variables, and intermediate or final results from the processing of equations, formulas, operations, and operational logic.

[0056] In some embodiments, memory inside of the processor 1010 and / or the encoder / decoder module 1030 is used to store instructions and to provide working memory for processing that is needed during encoding or decoding. In other embodiments, however, a memory external to the processing device (for example, the processing device can be either the processor 1010 or the encoder / decoder module 1030) is used for one or more of these functions. The external memory can be the memory 1020 and / or the storage device 1040, for example, a dynamic volatile memory and / or a non-volatile flash memory. In several embodiments, an external non-volatile flash memory is used to store the operating system of, for example, a television. In at least one embodiment, a fast external dynamic volatile memory such as a RAM is used as working memory for video coding and decoding operations, such as for MPEG-2 (MPEG refers to the Moving Picture Experts Group, MPEG-2 is also referred to as ISO / IEC 13818, and 13818-1 is also known as H.222, and 13818-2 is also known as H.262), HEVC (HEVC refers to 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).

[0057] The input to the elements of system 1000 can be provided through various input devices as indicated in block 1 130. Such input devices include, but are not limited to, (i) a radio frequency (RF) portion that receives an RF signal transmitted, for example, over the air by a broadcaster, (ii) a Component (COMP) input terminal (or a set of COMP input terminals), (iii) a Universal Serial Bus (USB) input terminal, and / or (iv) a High Definition Multimedia Interface (HDMI) input terminal.

[0058] In various embodiments, the input devices of block 1130 have associated respective input processing elements as known in the art. For example, the RF portion can be associated with elements suitable for (i) selecting a desired frequency (also referred to as selecting a signal, or band-limiting a signal to a band of frequencies), (ii) downconverting the selected signal, (iii) band-limiting again to a narrower band of frequencies to select (for example) a signal frequency band which can be referred to as a channel in certain embodiments, (iv)demodulating the downconverted and band-limited signal, (v) performing error correction, and (vi) demultiplexing to select the desired stream of data packets. The RF portion of various embodiments includes one or more elements to perform these functions, for example, frequency selectors, signal selectors, band-limiters, channel selectors, filters, downconverters, demodulators, error correctors, and demultiplexers. The RF portion can include a tuner that performs various of these functions, including, for example, downconverting the received signal to a lower frequency (for example, an intermediate frequency or a near-baseband frequency) or to baseband. In one set-top box embodiment, the RF portion and its associated input processing element receives an RF signal transmitted over a wired (for example, cable) medium, and performs frequency selection by filtering, downconverting, and filtering again to a desired frequency band. Various embodiments rearrange the order of the above-described (and other) elements, remove some of these elements, and / or add other elements performing similar or different functions. Adding elements can include inserting elements in between existing elements, such as, for example, inserting amplifiers and an analog-to-digital converter. In various embodiments, the RF portion includes an antenna.

[0059] Additionally, the USB and / or HDMI terminals can include respective interface processors for connecting system 1000 to other electronic devices across USB and / or HDMI connections. It is to be understood that various aspects of input processing, for example, Reed-Solomon error correction, can be implemented, for example, within a separate input processing IC or within processor 1010 as necessary. Similarly, aspects of USB or HDMI interface processing can be implemented within separate interface ICs or within processor 1010 as necessary. The demodulated, error corrected, and demultiplexed stream is provided to various processing elements, including, for example, processor 1010, and encoder / decoder 1030 operating in combination with the memory and storage elements to process the datastream as necessary for presentation on an output device.

[0060] Various elements of system 1000 can be provided within an integrated housing, Within the integrated housing, the various elements can be interconnected and transmit data therebetween using suitable connection arrangement 1 140, for example, an internal bus as known in the art, including the Inter- IC (I2C) bus, wiring, and printed circuit boards.

[0061] The system 1000 includes communication interface 1050 that enables communication with other devices via communication channel 1060. The communication interface 1050 can include, but is not limited to, a transceiver configured to transmit and to receive data over communication channel 1060. The communication interface 1050 can include, but is not limited to, a modem or network card and the communication channel 1060 can be implemented, for example, within a wired and / or a wireless medium.

[0062] Data is streamed, or otherwise provided, to the system 1000, in various embodiments, using a wireless network such as a Wi-Fi network, for example IEEE 802.11 (IEEE refers to the Institute of Electrical and Electronics Engineers). The Wi-Fi signal of these embodiments is received over the communications channel 1060 and the communications interface 1050 which are adapted for Wi-Fi communications. The communications channel 1060 of these embodiments is typically connected to an access point or router that provides access to external networks including the Internet for allowing streaming applications and other over- the-top communications. Other embodiments provide streamed data to the system 1000 using a set-top box that delivers the data over the HDMI connection of the input block 1 130. Still other embodiments provide streamed data to the system 1000 using the RF connection of the input block 1 130. As indicated above, various embodiments provide data in a non-streaming manner. Additionally, various embodiments use wireless networks other than Wi-Fi, for example a cellular network or a Bluetooth network.

[0063] The system 1000 can provide an output signal to various output devices, including a display 1 100, speakers 1110, and other peripheral devices 1 120. The display 1 100 of various embodiments includes one or more of, for example, a touchscreen display, an organic lightemitting diode (OLED) display, a curved display, and / or a foldable display. The display 1 100 can be for a television, a tablet, a laptop, a cell phone (mobile phone), or other device. The display 1 100 can also be integrated with other components (for example, as in a smart phone), or separate (for example, an external monitor for a laptop). The other peripheral devices 1 120 include, in various examples of embodiments, one or more of a stand-alone digital video disc (or digital versatile disc) (DVR, for both terms), a disk player, a stereo system, and / or a lighting system. Various embodiments use one or more peripheral devices 1 120 that provide a function based on the output of the system 1000. For example, a disk player performs the function of playing the output of the system 1000.

[0064] In various embodiments, control signals are communicated between the system 1000 and the display 1 100, speakers 1 110, or other peripheral devices 1120 using signaling such as AV. Link, Consumer Electronics Control (CEC), or other communications protocols that enable device-to-device control with or without user intervention. The output devices can be communicatively coupled to system 1000 via dedicated connections through respective interfaces 1070, 1080, and 1090. Alternatively, the output devices can be connected to system 1000 using the communications channel 1060 via the communications interface 1050. The display 1 100 and speakers 1 110 can be integrated in a single unit with the other components of system 1000 in an electronic device such as, for example, a television. In various embodiments, the display interface 1070 includes a display driver, such as, for example, a timing controller (T Con) chip.

[0065] The display 1100 and speaker 1 110 can alternatively be separate from one or more of the other components, for example, if the RF portion of input 1130 is part of a separate set- top box. In various embodiments in which the display 1100 and speakers 1 110 are external components, the output signal can be provided via dedicated output connections, including, for example, HDMI ports, USB ports, or COMP outputs.

[0066] The system 1000 may include one or more sensor devices 1095. Examples of sensor devices that may be used include one or more GPS sensors, gyroscopic sensors, accelerometers, light sensors, cameras, depth cameras, microphones, and / or magnetometers. Such sensors may be used to determine information such as user’s position and orientation. Where the system 1000 is used as the control module for an augmented reality display (such as control modules 124, 1254), the user’s position and orientation may be used in determining how to render image data such that the user perceives the correct portion of a virtual object or virtual scene from the correct point of view. In the case of headmounted display devices, the position and orientation of the device itself may be used to determine the position and orientation of the user for the purpose of rendering virtual content. In the case of other display devices, such as a phone, a tablet, a computer monitor, or a television, other inputs may be used to determine the position and orientation of the user for the purpose of rendering content. For example, a user may select and / or adjust a desired viewpoint and / or viewing direction with the use of a touch screen, keypad or keyboard, trackball, joystick, or other input. Where the display device has sensors such as accelerometers and / or gyroscopes, the viewpoint and orientation used for the purpose of rendering content may be selected and / or adjusted based on motion of the display device.

[0067] The embodiments can be carried out by computer software implemented by the processor 1010 or by hardware, or by a combination of hardware and software. As a nonlimiting example, the embodiments can be implemented by one or more integrated circuits. The memory 1020 can be of any type appropriate to the technical environment and can be implemented using any appropriate data storage technology, such as optical memory devices, magnetic memory devices, semiconductor-based memory devices, fixed memory, and removable memory, as non-limiting examples. The processor 1010 can be of any type appropriate to the technical environment, and can encompass one or more of microprocessors, general purpose computers, special purpose computers, and processors based on a multi-core architecture, as non-limiting examples.Further Embodiments.

[0068] A method according to some embodiments comprises: obtaining a plurality of tracked parameters and associated confidence levels; identifying at least a first one of the tracked parameters having an associated first confidence level below a first threshold associated with the first tracked parameter; identifying a first rendering action associated with a below- threshold confidence level of the first tracked parameter; and performing the first rendering action.

[0069] Some embodiments further comprise: identifying at least a second one of the tracked parameters having an associated second confidence level below a second threshold associated with the second tracked parameter; identifying a second rendering action associated with a below-threshold confidence level of the second tracked parameter; determining whether the second rendering action is compatible with the first rendering action; and performing the second rendering action in response to a determination that the second rendering action is compatible with the first rendering action.

[0070] Some embodiments further comprise: identifying at least a second one of the tracked parameters having an associated second confidence level below a second threshold associated with the second tracked parameter; identifying a second rendering action associated with a below-threshold confidence level of the second tracked parameter; and determining whether the second rendering action is compatible with the first rendering action; wherein, in response to a determination that the second rendering action is not compatible with the first rendering action, the second rendering action is not performed.

[0071] Some embodiments further comprise: identifying at least a second one of the tracked parameters having an associated second confidence level below a second threshold associated with the second tracked parameter; identifying a second rendering action associated with a below-threshold confidence level of the second tracked parameter; and determining whether the second rendering action has a higher priority than the first rendering action; wherein, in response to a determination that the second rendering action does not have a higher priority than the first rendering action, the second rendering action is not performed.

[0072] A method according to some embodiments comprises: obtaining at least a first tracked parameter (e.g. XR data such as pose, gesture, or gaze information, among other possibilities) and a first confidence level associated with the first tracked parameter; determining whether the first confidence level is below a first threshold associated with the first tracked parameter; and for at least one current frame of an extended reality presentation, in response to a determination that the first confidence level is below the first threshold, performing a predetermined first rendering action associated with the first tracked parameter.

[0073] In some embodiments, the predetermined first rendering action is at least one of: rendering the current frame using a most-recent value of the tracked parameter associated with a confidence level that is not below the first threshold; presenting a most-recently- rendered frame in place of the current frame; presenting a still image in place of the current frame; or presenting a fade-out effect. Other actions may be used as alternatives or in addition to these.

[0074] In some embodiments, the first tracked parameter is at least one of: a user pose; a user gaze direction; a pose of a trackable; a description of a user input; or a description of a user gesture.

[0075] In some embodiments, the method is performed by a client device in a standalone rendering architecture. In other embodiments, the method is performed by a split rendering server in a split rendering architecture.

[0076] When the method is performed by a split rendering server, in some embodiments, the method further includes receiving, from a client device in the split rendering architecture, data associating the first tracked parameter, the first threshold, and the first rendering action. Such data may be received during a setup process of an extended reality session. In some embodiments, such data may be received in a data object, such as one or more of the strategy objects with a syntax as provided herein.

[0077] Some embodiments further include receiving a plurality of data objects during the setup process, each data object associating a respective tracked parameter with at least one respective threshold and at least one respective rendering action. In some embodiments, a plurality of thresholds are provided in an array, an a plurality of rendering actions are identified in a corresponding array, with each threshold corresponding to a respective one of the rendering actions.

[0078] In some embodiments, the plurality of data objects include respective identifiers to distinguish different data objects associated with the same tracked parameter.

[0079] In some embodiments, the plurality of data objects include respective priority indicators, and wherein a determination of a rendering action is based at least in part on the priority indicators.

[0080] In some embodiments, the plurality of data objects include respective rendering type indicators, wherein the rendering type indicator indicates at least one of: audio rendering, visual rendering, or haptics rendering. The specified rendering action may affect only the identified type of rendering.

[0081] An apparatus according to some embodiments comprises one or more processors configured to perform at least: obtaining at least a first tracked parameter and a first confidence level associated with the first tracked parameter; determining whether the first confidence level is below a first threshold associated with the first tracked parameter; for at least one current frame of an extended reality presentation, based at least in part on a determination that the first confidence level is not below the first threshold, rendering the current frame based on the first tracked parameter; and for the current frame, in response to a determination that the first confidence level is below the first threshold, performing a predetermined first rendering action associated with the first tracked parameter.

[0082] This disclosure describes a variety of aspects, including tools, features, embodiments, models, approaches, etc. Many of these aspects are described with specificity and, at least to show the individual characteristics, are often described in a manner that may sound limiting. However, this is for purposes of clarity in description, and does not limit the disclosure or scope of those aspects. Indeed, all of the different aspects can be combined and interchanged to provide further aspects. Moreover, the aspects can be combined and interchanged with aspects described in earlier filings as well.

[0083] The aspects described and contemplated in this disclosure can be implemented in many different forms. While some embodiments are illustrated specifically, other embodiments are contemplated, and the discussion of particular embodiments does not limit the breadth of the implementations. At least one of the aspects generally relates to encoding and decoding, and at least one other aspect generally relates to transmitting a bitstream generated or encoded. These and other aspects can be implemented as a method, an apparatus, a computer readable storage medium having stored thereon instructions for encoding or decoding XR content data according to any of the methods described, and / or a computer readable storage medium having stored thereon a bitstream generated according to any of the methods described.

[0084] Various methods are described herein, and each of the methods comprises 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”, etc. may be used in various embodiments to modify an element, component, step, operation, etc., such as, for example, a “first decoding” and a “second decoding”. Use of such terms does not imply an ordering to the modified operations unless specifically required. So, in this example, the first decoding need not be performed before the second decoding, and may occur, for example, before, during, or in an overlapping time period with the second decoding.

[0085] Various numeric values may be used in the present disclosure, for example. The specific values are for example purposes and the aspects described are not limited to these specific values.

[0086] Embodiments described herein may be carried out by computer software implemented by a processor or other hardware, or by a combination of hardware and software. As a nonlimiting example, the embodiments can be implemented by one or more integrated circuits. The processor can be of any type appropriate to the technical environment and can encompass one or more of microprocessors, general purpose computers, special purpose computers, and processors based on a multi-core architecture, as non-limiting examples.

[0087] When a figure is presented as a flow diagram, it should be understood that it also provides a block diagram of a corresponding apparatus. Similarly, when a figure is presented as a block diagram, it should be understood that it also provides a flow diagram of a corresponding method / process.

[0088] The implementations and aspects described herein can be implemented in, for example, a method or a process, an apparatus, a software program, a data stream, or a signal. Even if only discussed in the context of a single form of implementation (for example, discussed only as a method), the implementation of features discussed can also be implemented in other forms (for example, an apparatus or program). An apparatus can be implemented in, for example, appropriate hardware, software, and firmware. The methods can be implemented in, for example, a processor, which refers to processing devices in general, including, for example, a computer, a microprocessor, an integrated circuit, or a programmable logic device. Processors also include communication devices, such as, for example, computers, cell phones, portable / personal digital assistants (“PDAs”), and other devices that facilitate communication of information between end-users.

[0089] Reference to “one embodiment” or “an embodiment” or “one implementation” or “an implementation”, as well as other variations thereof, means that a particular feature, structure, characteristic, and so forth described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase “in one embodiment” or “in an embodiment” or “in one implementation” or “in an implementation”, as well any other variations, appearing in various places throughout this disclosure are not necessarily all referring to the same embodiment.

[0090] Additionally, this disclosure may refer to “determining” various pieces of information. Determining the information can include one or more of, for example, estimating the information, calculating the information, predicting the information, or retrieving the information from memory.

[0091] Further, this disclosure may refer to “accessing” various pieces of information. Accessing the information can include one or more of, for example, receiving the information, retrieving the information (for example, from memory), storing the information, moving the information, copying the information, calculating the information, determining the information, predicting the information, or estimating the information.

[0092] Additionally, this disclosure may refer to “receiving” various pieces of information. Receiving is, as with “accessing”, intended to be a broad term. Receiving the information can include one or more of, for example, accessing the information, or retrieving the information (for example, from memory). Further, “receiving” is typically involved, in one way or another, during operations such as, for example, storing the information, processing the information, transmitting the information, moving the information, copying the information, erasing the information, calculating the information, determining the information, predicting the information, or estimating the information.

[0093] It is to be appreciated that the use of any of the following“and / or”, and “at least one of’, for example, in the cases of “A / B”, “A and / or B” and “at least one of A and B”, is intended to encompass the selection of the first listed option (A) only, or the selection of the second listed option (B) only, or the selection of both options (A and B). As a further example, in the cases of “A, B, and / or C” and “at least one of A, B, and C”, such phrasing is intended to encompass the selection of the first listed option (A) only, or the selection of the second listed option (B) only, or the selection of the third listed option (C) only, or the selection of the first and the second listed options (A and B) only, or the selection of the first and third listed options (A and C) only, or the selection of the second and third listed options (B and C) only, or the selection of all three options (A and B and C). This may be extended for as many items as are listed.

[0094] Also, as used herein, the word “signal” refers to, among other things, indicating something to a corresponding decoder. For example, in certain embodiments the encoder signals a particular one of a plurality of parameters for region-based filter parameter selection for de-artifact filtering. In this way, in an embodiment the same parameter is used at both the encoder side and the decoder side. Thus, for example, an encoder can transmit (explicit signaling) a particular parameter to the decoder so that the decoder can use the same particular parameter. Conversely, if the decoder already has the particular parameter as well as others, then signaling can be used without transmitting (implicit signaling) to simply allow the decoder to know and select the particular parameter. By avoiding transmission of any actual functions, a bit savings is realized in various embodiments. It is to be appreciated that signaling can be accomplished in a variety of ways. For example, one or more syntax elements, flags, and so forth are used to signal information to a corresponding decoder invarious embodiments. While the preceding relates to the verb form of the word “signal”, the word “signal” can also be used herein as a noun.

[0095] Implementations can produce a variety of signals formatted to carry information that can be, for example, stored or transmitted. The information can include, for example, instructions for performing a method, or data produced by one of the described implementations. For example, a signal can be formatted to carry the bitstream of a described embodiment. Such a signal can be formatted, for example, as an electromagnetic wave (for example, using a radio frequency portion of spectrum) or as a baseband signal. The formatting can include, for example, encoding a data stream and modulating a carrier with the encoded data stream. The information that the signal carries can be, for example, analog or digital information. The signal can be transmitted over a variety of different wired or wireless links, as is known. The signal can be stored on a processor-readable medium.

[0096] We describe a number of embodiments. Features of these embodiments can be provided alone or in any combination, across various claim categories and types. Further, embodiments can include one or more of the following features, devices, or aspects, alone or in any combination, across various claim categories and types:• A bitstream or signal that includes one or more of the described syntax elements, or variations thereof.• A bitstream or signal that includes syntax conveying information generated according to any of the embodiments described.• Creating and / or transmitting and / or receiving and / or decoding a bitstream or signal that includes one or more of the described syntax elements, or variations thereof.• Creating and / or transmitting and / or receiving and / or decoding according to any of the embodiments described.• A method, process, apparatus, medium storing instructions, medium storing data, or signal according to any of the embodiments described.

[0097] Note that various hardware elements of one or more of the described embodiments may be referred to as “modules” that carry out (i.e. , perform, execute, and the like) various functions that are described herein in connection with the respective modules. As used herein, a module includes hardware (e.g., one or more processors, one or more microprocessors, one or more microcontrollers, one or more microchips, one or more application-specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more memory devices) deemed suitable for a given implementation. Each described module may also include instructions executable for carrying out the one or more functions described as being carried out by the respective module, and it is noted that those instructions could take the form of or include hardware (i.e., hardwired) instructions, firmware instructions, software instructions, and / or the like, and may be stored in any suitable non-transitory computer- readable medium or media, such as commonly referred to as RAM, ROM, etc.

[0098] Although features and elements are described above in particular combinations, each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, 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 WTRLI, LIE, terminal, base station, RNC, or any host computer.

Claims

CLAIMS1 . A method comprising: obtaining a plurality of tracked parameters and associated confidence levels; identifying at least a first one of the tracked parameters having an associated first confidence level below a first threshold associated with the first tracked parameter identifying a first rendering action associated with a below-threshold confidence level of the first tracked parameter; and performing the first rendering action.

2. An apparatus comprising one or more processors configured to perform at least: obtaining a plurality of tracked parameters and associated confidence levels; identifying at least a first one of the tracked parameters having an associated first confidence level below a first threshold associated with the first tracked parameter identifying a first rendering action associated with a below-threshold confidence level of the first tracked parameter; and performing the first rendering action.

3. The method of claim 1 or the apparatus of claim 2, further comprising: identifying at least a second one of the tracked parameters having an associated second confidence level below a second threshold associated with the second tracked parameter; identifying a second rendering action associated with a below-threshold confidence level of the second tracked parameter; determining whether the second rendering action is compatible with the first rendering action; and performing the second rendering action in response to a determination that the second rendering action is compatible with the first rendering action.

4. The method of claim 1 or the apparatus of claim 2, further comprising: identifying at least a second one of the tracked parameters having an associated second confidence level below a second threshold associated with the second tracked parameter; identifying a second rendering action associated with a below-threshold confidence level of the second tracked parameter; anddetermining whether the second rendering action is compatible with the first rendering action; wherein, in response to a determination that the second rendering action is not compatible with the first rendering action, the second rendering action is not performed.

5. The method of claim 1 or the apparatus of claim 2, further comprising: identifying at least a second one of the tracked parameters having an associated second confidence level below a second threshold associated with the second tracked parameter; identifying a second rendering action associated with a below-threshold confidence level of the second tracked parameter; and determining whether the second rendering action has a higher priority than the first rendering action; wherein, in response to a determination that the second rendering action does not have a higher priority than the first rendering action, the second rendering action is not performed.

6. The method of claim 1 , or claims 3-5 as they depend from claim 1 , or the apparatus of claim 2, or claims 3-5 as they depend from claim 2, wherein the first rendering action is at least one of: rendering the current frame using a most-recent value of the tracked parameter associated with a confidence level that is not below the first threshold; presenting a most-recently-rendered frame in place of the current frame; presenting a still image in place of the current frame; or presenting a fade-out effect.

7. The method of claim 1 , or claims 3-5 as they depend from claim 1 , or the apparatus of claim 2, or claims 3-5 as they depend from claim 2, wherein the first rendering action and the second rendering action are two different actions selected from the following actions: rendering the current frame using a most-recent value of the tracked parameter associated with a confidence level that is not below the first threshold; presenting a most-recently-rendered frame in place of the current frame; presenting a still image in place of the current frame; or presenting a fade-out effect.

8. The method of claim 1 , or claims 3-7 as they depend from claim 1 , or the apparatus of claim 2, or claims 3-7 as they depend from claim 2, wherein the plurality of tracked parameters include at least two different parameters selected from the following parameters: a user pose; a user gaze direction; a pose of a trackable; a description of a user input; or a description of a user gesture.

9. The method of claim 1 , or claims 3-5 as they depend from claim 1 , or the apparatus of claim 2, or claims 3-5 as they depend from claim 2, wherein the first tracked parameter and the second tracked parameter are two different parameters selected from the following parameters: a user pose; a user gaze direction; a pose of a trackable; a description of a user input; or a description of a user gesture.

10. The method of claim 1 , or claims 3-9 as they depend from claim 1 , or the apparatus of claim 2, or claims 3-9 as they depend from claim 2, implemented by a client device in a standalone rendering architecture.

11. The method of claim 1 , or claims 3-9 as they depend from claim 1 , or the apparatus of claim 2, or claims 3-9 as they depend from claim 2, implemented by a split rendering server in a split rendering architecture.

12. The method of claim 11 as it depends from claim 1 , or the apparatus of claim 11 as it depends from claim 2, further comprising receiving, from a client device in the split rendering architecture, data associating the first tracked parameter, the first threshold, and the first rendering action.

13. The method of claim 12 as it depends from claim 1 , or the apparatus of claim 12 as it depends from claim 2, wherein the data associating the first tracked parameter, the first threshold, and the first rendering action is received during a setup process of an extended reality session.

14. The method of claim 13 as it depends from claim 1, or the apparatus of claim 13 as it depends from claim 2, further comprising receiving a plurality of data objects during the setup process, each data object associating a respective tracked parameter with at least one respective threshold and at least one respective rendering action.

15. The method of claim 14 as it depends from claim 1, or the apparatus of claim 14 as it depends from claim 2, wherein the plurality of data objects include respective priority indicators, and wherein the performing of the first rendering action is conditioned at least in part on the priority indicators.