Patent Publication Number: US-2022217318-A1

Title: V3c video component track alternatives

Description:
CROSS-REFERENCE TO RELATED APPLICATION AND PRIORITY CLAIM 
     This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 63/134,006 filed on Jan. 5, 2021, U.S. Provisional Patent Application No. 63/136,265 filed on Jan. 12, 2021, U.S. Provisional Patent Application No. 63/171,369 filed on Apr. 6, 2021, U.S. Provisional Patent Application No. 63/179,744 filed on Apr. 26, 2021 and U.S. Provisional Patent Application No. 63/181,056 filed on Apr. 28, 2021, which are hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     This disclosure relates generally to video processing devices and processes. More specifically, this disclosure relates to visual volumetric video-based coding (V3C) video component track alternatives. 
     BACKGROUND 
     ISO/IEC 23090-10 carriage of visual volumetric video-based coding (V3C) data supports alternative representation of V3C video component tracks. However, the use of such features with the combination with a V3C atlas tile track is not fully provided. 
     SUMMARY 
     This disclosure provides V3C video component track alternatives. 
     In a first embodiment, a decoding device includes a communication interface and a processor operably coupled to the communication interface. The communication interface is configured to receive a plurality of tracks in a compressed bitstream. The processor is configured to identify an atlas track corresponding to a point cloud compression (PCC) component and identify a set of first component tracks that is referenced by the atlas track and at least one second component track, each of the at least one second component track is an alternative version of a first component track of the set of first component tracks. The processor is also configured to determine which of the set of first component tracks and the at least one second component track are appropriate versions of the PCC component. The processor is further configured to decode the appropriate version of the PCC component from among the set of first component tracks and the at least one second component track. 
     In a second embodiment, a decoding device includes a communication interface and a processor operably coupled to the communication interface. The communication interface is configured to receive a dynamic adaptive streaming over HTTP (DASH) media presentation description (MPD) about a point cloud compression (PCC) data and a plurality of tracks in a compressed bitstream. The processor is configured to, based on information in the DASH MPD, identify a first atlas bitstream and a second atlas bitstream that is an alternative version of the first atlas bitstream based on the first atlas bitstream and the second atlas bitstream having a same value of an atlas ID. The processor is also configured to determine which of a first atlas track and a second atlas track is an appropriate version of the PCC data. The processor is further configured to decode the appropriate version of the PCC data. 
     In a third embodiment, a method includes receiving a plurality of tracks in a compressed bitstream. The method also includes identifying an atlas track corresponding to a point cloud compression (PCC) component and identifying a set of first component tracks that is referenced by the atlas track and at least one second component track, each of the at least one second component track is an alternative version of a first component track of the set of first component tracks. The method further includes determining which of the set of first component tracks and the at least one second component track are appropriate versions of the PCC component. In addition, the method includes decoding the appropriate version of the PCC component from among the set of first component tracks and the at least one second component track. 
     In a fourth embodiment, an encoder device includes a processor and a communication interface operably coupled to the processor. The processor is configured to encode an atlas track corresponding to a point cloud compression (PCC) component. The processor is also configured to encode the PCC component in a first component track that references the atlas track. The processor is further configured to encode an alternative version of the PCC component from the first component track in a second component track. The communication interface is configured to transmit a compressed bitstream including the atlas track, the first component track, and the second component track. 
     Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims. 
     Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term “couple” and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with one another. The terms “transmit,” “receive,” and “communicate,” as well as derivatives thereof, encompass both direct and indirect communication. The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and/or. The phrase “associated with,” as well as derivatives thereof, means to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The term “controller” means any device, system, or part thereof that controls at least one operation. Such a controller may be implemented in hardware or a combination of hardware and software and/or firmware. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase “at least one of,” when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be needed. For example, “at least one of: A, B, and C” includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C. 
     Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A “non-transitory” computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device. 
     Definitions for other certain words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many if not most instances, such definitions apply to prior as well as future uses of such defined words and phrases. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts: 
         FIG. 1  illustrates an example communication system in accordance with an embodiment of this disclosure; 
         FIGS. 2 and 3  illustrate example electronic devices in accordance with an embodiment of this disclosure; 
         FIG. 4  illustrates a block diagram of an example environment-architecture in accordance with an embodiment of this disclosure; 
         FIGS. 5A-5C  illustrates an example files in accordance with this disclosure; and 
         FIG. 6  illustrates an example method for V3C video component track alternatives according to this disclosure. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 through 6 , described below, and the various embodiments used to describe the principles of the present disclosure are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any type of suitably arranged device or system. 
     Alternative content representation is defined in ISO/IEC 23090-10 Carriage of Video-based Point Cloud Compression Data in a very high level. 1.1.1.1 V3C content alternatives provide that V3C content may be encoded as different versions in the file format. Different alternatives are indicated by the alternative tracks mechanism defined in ISO/IEC 14496-12 (i.e., altenate_group field of the TrackHeaderBox). V3C atlas tracks which have the same alternate_group value shall be different versions of the same V3C content. 
     1.1.1.2 V3C video component alternatives provides that V3C video component tracks may have alternatives. In such a case, only ne of the V3C video component tracks that belong to an alternative group shall be referenced by the V3C atlas track or V3C atlas tile track. V3C video component tracks which are alternatives of each other should use the alternate grouping mechanism, as defined in ISO/IEC 14496-12. 
     As a single content of V-PCC is composed of many components and combination of components that can widely vary. A detailed description about complicated or complex cases needs further defining. When a V3C content has alternatives, a sample entry of a track belongs to all V3C contents in an alternative relationship that may not provide enough information to show the differences between alternative versions. The application may use additional external mechanisms, e.g., dynamic adaptive streaming over HTTP (DASH) media presentation description (MPD), scene descriptions, etc., to get information to select one appropriate version for display. 
       FIG. 1  illustrates an example communication system  100  in accordance with an embodiment of this disclosure. The embodiment of the communication system  100  shown in  FIG. 1  is for illustration only. Other embodiments of the communication system  100  can be used without departing from the scope of this disclosure. 
     The communication system  100  includes a network  102  that facilitates communication between various components in the communication system  100 . For example, the network  102  can communicate IP packets, frame relay frames, Asynchronous Transfer Mode (ATM) cells, or other information between network addresses. The network  102  includes one or more local area networks (LANs), metropolitan area networks (MANs), wide area networks (WANs), all or a portion of a global network such as the Internet, or any other communication system or systems at one or more locations. 
     In this example, the network  102  facilitates communications between a server  104  and various client devices  106 - 116 . The client devices  106 - 116  may be, for example, a smartphone, a tablet computer, a laptop, a personal computer, a wearable device, a HMD, or the like. The server  104  can represent one or more servers. Each server  104  includes any suitable computing or processing device that can provide computing services for one or more client devices, such as the client devices  106 - 116 . Each server  104  could, for example, include one or more processing devices, one or more memories storing instructions and data, and one or more network interfaces facilitating communication over the network  102 . As described in more detail below, the server  104  can transmit a compressed bitstream, representing a point cloud, to one or more display devices, such as a client device  106 - 116 . In certain embodiments, each server  104  can include an encoder. 
     Each client device  106 - 116  represents any suitable computing or processing device that interacts with at least one server (such as the server  104 ) or other computing device(s) over the network  102 . The client devices  106 - 116  include a desktop computer  106 , a mobile telephone or mobile device  108  (such as a smartphone), a PDA  110 , a laptop computer  112 , a tablet computer  114 , and an HMD  116 . However, any other or additional client devices could be used in the communication system  100 . Smartphones represent a class of mobile devices  108  that are handheld devices with mobile operating systems and integrated mobile broadband cellular network connections for voice, short message service (SMS), and Internet data communications. The HMD  116  can display a 360° scene including one or more 3D point clouds. In certain embodiments, any of the client devices  106 - 116  can include an encoder, decoder, or both. For example, the mobile device  108  can record a video and then encode the video enabling the video to be transmitted to one of the client devices  106 - 116 . In another example, the laptop computer  112  can be used to generate a virtual 3D point cloud, which is then encoded and transmitted to one of the client devices  106 - 116 . 
     In this example, some client devices  108 - 116  communicate indirectly with the network  102 . For example, the mobile device  108  and PDA  110  communicate via one or more base stations  118 , such as cellular base stations or eNodeBs (eNBs). Also, the laptop computer  112 , the tablet computer  114 , and the HMD  116  communicate via one or more wireless access points  120 , such as IEEE 802.11 wireless access points. Note that these are for illustration only and that each client device  106 - 116  could communicate directly with the network  102  or indirectly with the network  102  via any suitable intermediate device(s) or network(s). In certain embodiments, the server  104  or any client device  106 - 116  can be used to compress a point cloud, generate a bitstream that represents the point cloud, and transmit the bitstream to another client device such as any client device  106 - 116 . 
     In certain embodiments, any of the client devices  106 - 114  transmit information securely and efficiently to another device, such as, for example, the server  104 . Also, any of the client devices  106 - 116  can trigger the information transmission between itself and the server  104 . Any of the client devices  106 - 114  can function as a VR display when attached to a headset via brackets, and function similar to HMD  116 . For example, the mobile device  108  when attached to a bracket system and worn over the eyes of a user can function similarly as the HMD  116 . The mobile device  108  (or any other client device  106 - 116 ) can trigger the information transmission between itself and the server  104 . 
     In certain embodiments, any of the client devices  106 - 116  or the server  104  can create a 3D point cloud, compress a 3D point cloud, transmit a 3D point cloud, receive a 3D point cloud, render a 3D point cloud, or a combination thereof. For example, the server  104  can then compress 3D point cloud to generate a bitstream and then transmit the bitstream to one or more of the client devices  106 - 116 . For another example, one of the client devices  106 - 116  can compress a 3D point cloud to generate a bitstream and then transmit the bitstream to another one of the client devices  106 - 116  or to the server  104 . 
     Although  FIG. 1  illustrates one example of a communication system  100 , various changes can be made to  FIG. 1 . For example, the communication system  100  could include any number of each component in any suitable arrangement. In general, computing and communication systems come in a wide variety of configurations, and  FIG. 1  does not limit the scope of this disclosure to any particular configuration. While  FIG. 1  illustrates one operational environment in which various features disclosed in this patent document can be used, these features could be used in any other suitable system. 
       FIGS. 2 and 3  illustrate example electronic devices in accordance with an embodiment of this disclosure. In particular,  FIG. 2  illustrates an example server  200 , and the server  200  could represent the server  104  in  FIG. 1 . The server  200  can represent one or more encoders, decoders, local servers, remote servers, clustered computers, and components that act as a single pool of seamless resources, a cloud-based server, and the like. The server  200  can be accessed by one or more of the client devices  106 - 116  of  FIG. 1  or another server. 
     As shown in  FIG. 2 , the server  200  includes a bus system  205  that supports communication between at least one processing device (such as a processor  210 ), at least one storage device  215 , at least one communications interface  220 , and at least one input/output (I/O) unit  225 . The server  200  can represent one or more local servers, one or more compression servers, or one or more encoding servers, such as an encoder. In certain embodiments, the encoder can perform decoding. 
     The processor  210  executes instructions that can be stored in a memory  230 . The processor  210  can include any suitable number(s) and type(s) of processors or other devices in any suitable arrangement. Example types of processors  210  include microprocessors, microcontrollers, digital signal processors, field programmable gate arrays, application specific integrated circuits, and discrete circuitry. In certain embodiments, the processor  210  can encode a 3D point cloud stored within the storage devices  215 . In certain embodiments, encoding a 3D point cloud also decodes the 3D point cloud to ensure that when the point cloud is reconstructed, the reconstructed 3D point cloud matches the 3D point cloud prior to the encoding. 
     The memory  230  and a persistent storage  235  are examples of storage devices  215  that represent any structure(s) capable of storing and facilitating retrieval of information (such as data, program code, or other suitable information on a temporary or permanent basis). The memory  230  can represent a random-access memory or any other suitable volatile or non-volatile storage device(s). For example, the instructions stored in the memory  230  can include instructions for encode an atlas track corresponding to a PCC component, instructions for encoding the PCC component in a first component track that references the atlas tracks, instructions for encoding an alternative version of the PCC component from the first component track in a second component track, as well as instructions for transmitting a compressed bitstream including the atlas track, the first component track, and the second component track. 
     The instructions stored in the memory  230  can also include instructions for receiving a plurality of tracks in a compressed bitstream, instructions for identifying an atlas track corresponding to a PCC component, instructions for identifying a set of first component tracks that is referenced by the atlas track and at least one second component track, instructions for determining which of the set of first component tracks and the at least one second component track are appropriate versions of the PCC component; and instructions for decoding the appropriate version of the PCC component from among the set of first component tracks and the at least one second component tracks. The instructions stored in the memory  230  can also include instructions for rendering a 360° scene, as viewed through a VR headset, such as HMD  116  of  FIG. 1 . The persistent storage  235  can contain one or more components or devices supporting longer-term storage of data, such as a read only memory, hard drive, Flash memory, or optical disc. 
     The communications interface  220  supports communications with other systems or devices. For example, the communications interface  220  could include a network interface card or a wireless transceiver facilitating communications over the network  102  of  FIG. 1 . The communications interface  220  can support communications through any suitable physical or wireless communication link(s). For example, the communications interface  220  can transmit a bitstream containing a 3D point cloud to another device such as one of the client devices  106 - 116 . 
     The I/O unit  225  allows for input and output of data. For example, the I/O unit  225  can provide a connection for user input through a keyboard, mouse, keypad, touchscreen, or other suitable input device. The I/O unit  225  can also send output to a display, printer, or other suitable output device. Note, however, that the I/O unit  225  can be omitted, such as when I/O interactions with the server  200  occur via a network connection. 
     Note that while  FIG. 2  is described as representing the server  104  of  FIG. 1 , the same or similar structure could be used in one or more of the various client devices  106 - 116 . For example, a desktop computer  106  or a laptop computer  112  could have the same or similar structure as that shown in  FIG. 2 . 
       FIG. 3  illustrates an example electronic device  300 , and the electronic device  300  could represent one or more of the client devices  106 - 116  in  FIG. 1 . The electronic device  300  can be a mobile communication device, such as, for example, a mobile station, a subscriber station, a wireless terminal, a desktop computer (similar to the desktop computer  106  of  FIG. 1 ), a portable electronic device (similar to the mobile device  108 , the PDA  110 , the laptop computer  112 , the tablet computer  114 , or the HMD  116  of  FIG. 1 ), and the like. In certain embodiments, one or more of the client devices  106 - 116  of  FIG. 1  can include the same or similar configuration as the electronic device  300 . In certain embodiments, the electronic device  300  is an encoder, a decoder, or both. For example, the electronic device  300  is usable with data transfer, image or video compression, image or video decompression, encoding, decoding, and media rendering applications. 
     As shown in  FIG. 3 , the electronic device  300  includes an antenna  305 , a radio-frequency (RF) transceiver  310 , transmit (TX) processing circuitry  315 , a microphone  320 , and receive (RX) processing circuitry  325 . The RF transceiver  310  can include, for example, a RF transceiver, a BLUETOOTH transceiver, a WI-FI transceiver, a ZIGBEE transceiver, an infrared transceiver, and various other wireless communication signals. The electronic device  300  also includes a speaker  330 , a processor  340 , an input/output (I/O) interface (IF)  345 , an input  350 , a display  355 , a memory  360 , and a sensor(s)  365 . The memory  360  includes an operating system (OS)  361 , and one or more applications  362 . 
     The RF transceiver  310  receives, from the antenna  305 , an incoming RF signal transmitted from an access point (such as a base station, WI-FI router, or BLUETOOTH device) or other device of the network  102  (such as a WI-FI, BLUETOOTH, cellular, 5G, LTE, LTE-A, WiMAX, or any other type of wireless network). The RF transceiver  310  down-converts the incoming RF signal to generate an intermediate frequency or baseband signal. The intermediate frequency or baseband signal is sent to the RX processing circuitry  325  that generates a processed baseband signal by filtering, decoding, and/or digitizing the baseband or intermediate frequency signal. The RX processing circuitry  325  transmits the processed baseband signal to the speaker  330  (such as for voice data) or to the processor  340  for further processing (such as for web browsing data). 
     The TX processing circuitry  315  receives analog or digital voice data from the microphone  320  or other outgoing baseband data from the processor  340 . The outgoing baseband data can include web data, e-mail, or interactive video game data. The TX processing circuitry  315  encodes, multiplexes, and/or digitizes the outgoing baseband data to generate a processed baseband or intermediate frequency signal. The RF transceiver  310  receives the outgoing processed baseband or intermediate frequency signal from the TX processing circuitry  315  and up-converts the baseband or intermediate frequency signal to an RF signal that is transmitted via the antenna  305 . 
     The processor  340  can include one or more processors or other processing devices. The processor  340  can execute instructions that are stored in the memory  360 , such as the OS  361  in order to control the overall operation of the electronic device  300 . For example, the processor  340  could control the reception of forward channel signals and the transmission of reverse channel signals by the RF transceiver  310 , the RX processing circuitry  325 , and the TX processing circuitry  315  in accordance with well-known principles. The processor  340  can include any suitable number(s) and type(s) of processors or other devices in any suitable arrangement. For example, in certain embodiments, the processor  340  includes at least one microprocessor or microcontroller. Example types of processor  340  include microprocessors, microcontrollers, digital signal processors, field programmable gate arrays, application specific integrated circuits, and discrete circuitry. 
     The processor  340  is also capable of executing other processes and programs resident in the memory  360 , such as operations that receive and store data. The processor  340  can move data into or out of the memory  360  as required by an executing process. In certain embodiments, the processor  340  is configured to execute the one or more applications  362  based on the OS  361  or in response to signals received from external source(s) or an operator. Example, applications  362  can include an encoder, a decoder, a VR or AR application, a camera application (for still images and videos), a video phone call application, an email client, a social media client, a SMS messaging client, a virtual assistant, and the like. In certain embodiments, the processor  340  is configured to receive and transmit media content. 
     The processor  340  is also coupled to the I/O interface  345  that provides the electronic device  300  with the ability to connect to other devices, such as client devices  106 - 114 . The I/O interface  345  is the communication path between these accessories and the processor  340 . 
     The processor  340  is also coupled to the input  350  and the display  355 . The operator of the electronic device  300  can use the input  350  to enter data or inputs into the electronic device  300 . The input  350  can be a keyboard, touchscreen, mouse, track ball, voice input, or other device capable of acting as a user interface to allow a user in interact with the electronic device  300 . For example, the input  350  can include voice recognition processing, thereby allowing a user to input a voice command. In another example, the input  350  can include a touch panel, a (digital) pen sensor, a key, or an ultrasonic input device. The touch panel can recognize, for example, a touch input in at least one scheme, such as a capacitive scheme, a pressure sensitive scheme, an infrared scheme, or an ultrasonic scheme. The input  350  can be associated with the sensor(s)  365  and/or a camera by providing additional input to the processor  340 . In certain embodiments, the sensor  365  includes one or more inertial measurement units (IMUs) (such as accelerometers, gyroscope, and magnetometer), motion sensors, optical sensors, cameras, pressure sensors, heart rate sensors, altimeter, and the like. The input  350  can also include a control circuit. In the capacitive scheme, the input  350  can recognize touch or proximity. 
     The display  355  can be a liquid crystal display (LCD), light-emitting diode (LED) display, organic LED (OLED), active matrix OLED (AMOLED), or other display capable of rendering text and/or graphics, such as from websites, videos, games, images, and the like. The display  355  can be sized to fit within an HMD. The display  355  can be a singular display screen or multiple display screens capable of creating a stereoscopic display. In certain embodiments, the display  355  is a heads-up display (HUD). The display  355  can display 3D objects, such as a 3D point cloud. 
     The memory  360  is coupled to the processor  340 . Part of the memory  360  could include a RAM, and another part of the memory  360  could include a Flash memory or other ROM. The memory  360  can include persistent storage (not shown) that represents any structure(s) capable of storing and facilitating retrieval of information (such as data, program code, and/or other suitable information). The memory  360  can contain one or more components or devices supporting longer-term storage of data, such as a read only memory, hard drive, Flash memory, or optical disc. The memory  360  also can contain media content. The media content can include various types of media such as images, videos, three-dimensional content, VR content, AR content, 3D point clouds, and the like. 
     The electronic device  300  further includes one or more sensors  365  that can meter a physical quantity or detect an activation state of the electronic device  300  and convert metered or detected information into an electrical signal. For example, the sensor  365  can include one or more buttons for touch input, a camera, a gesture sensor, an IMU sensors (such as a gyroscope or gyro sensor and an accelerometer), an eye tracking sensor, an air pressure sensor, a magnetic sensor or magnetometer, a grip sensor, a proximity sensor, a color sensor, a bio-physical sensor, a temperature/humidity sensor, an illumination sensor, an Ultraviolet (UV) sensor, an Electromyography (EMG) sensor, an Electroencephalogram (EEG) sensor, an Electrocardiogram (ECG) sensor, an IR sensor, an ultrasound sensor, an iris sensor, a fingerprint sensor, a color sensor (such as a Red Green Blue (RGB) sensor), and the like. The sensor  365  can further include control circuits for controlling any of the sensors included therein. 
     The electronic device  300  can encode an atlas track corresponding to a PCC component. The electronic device  300  can encode the PCC component in a first component track that references the atlas track. The electronic device  300  can encode an alternative version of the PCC component from the first component track in a second component track. The electronic device  300  can transmit a compressed bitstream including the atlas track, the first component track, and the second component track. The electronic device  300  can encode the media content to generate a bitstream, such that the bitstream can be transmitted directly to another electronic device or indirectly such as through the network  102  of  FIG. 1 . Another electronic device, similar to the electronic device  300 , can receive a bitstream directly from the electronic device  300  or indirectly such as through the network  102  of  FIG. 1 . 
     Similarly, when decoding media content included in a bitstream that represents a 3D point cloud, the electronic device  300  receives a compressed bitstream. In certain embodiments, the electronic device  300  can identify an atlas track corresponding to a PCC component. The electronic device  300  can identify a set of first component tracks that is referenced by the atlas track and at least one second component track, where each of the at least one second component track is an alternative version of a first component track of the set of first component tracks. The electronic device  300  can determine which of the set of first component tracks and the at least one second component tracks are appropriate versions of the PCC component. The electronic device  300  can decode the appropriate version of the PCC component from among the set of first component tracks and the at least one second component track. In certain embodiments, after reconstructing the 3D point cloud, the electronic device  300  can render the 3D point cloud in three dimensions via the display  355 . 
     Although  FIGS. 2 and 3  illustrate examples of electronic devices, various changes can be made to  FIGS. 2 and 3 . For example, various components in  FIGS. 2 and 3  could be combined, further subdivided, or omitted and additional components could be added according to particular needs. As a particular example, the processor  340  could be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). In addition, as with computing and communication, electronic devices and servers can come in a wide variety of configurations, and  FIGS. 2 and 3  do not limit this disclosure to any particular electronic device or server. 
       FIG. 4  illustrates a block diagram of an example environment-architecture  400  for storage of V3C video component alternatives in accordance with an embodiment of this disclosure. The embodiment of  FIG. 4  is for illustration only. Other embodiments can be used without departing from the scope of this disclosure. 
     As shown in  FIG. 4 , the example environment-architecture  400  includes an encoder  410  and a decoder  450  in communication over a network  402 . The network  402  can be the same as or similar to the network  102  of  FIG. 1 . In certain embodiments, the network  402  represents a “cloud” of computers interconnected by one or more networks, where the network is a computing system utilizing clustered computers and components that act as a single pool of seamless resources when accessed. Also, in certain embodiments, the network  402  is connected with one or more servers (such as the server  104  of  FIG. 1 , the server  200 ), one or more electronic devices (such as the client devices  106 - 116  of  FIG. 1 , the electronic device  300 ), the encoder  410 , and the decoder  450 . Further, in certain embodiments, the network  402  can be connected to an information repository (not shown) that contains media content that can be encoded by the encoder  410 , decoded by the decoder  450 , or rendered and displayed on an electronic device. 
     In certain embodiments, the encoder  410  and the decoder  450  can represent the server  104 , one of the client devices  106 - 116  of  FIG. 1 , or another suitable device. The encoder  410  and the decoder  450  can include internal components similar to the server  200  of  FIG. 2  and electronic device  300  of  FIG. 3 . In certain embodiments, the encoder  410  and the decoder  450  can be a “cloud” of computers interconnected by one or more networks, where each is a computing system utilizing clustered computers and components to act as a single pool of seamless resources when accessed through the network  402 . In some embodiments, a portion of the components included in the encoder  410  or the decoder  450  can be included in different devices, such as multiple servers  104  or  200 , multiple client devices  106 - 116 , or other combination of different devices. In certain embodiments, the encoder  410  is operably connected to an electronic device or a server while the decoder  450  is operably connected to an electronic device. In certain embodiments, the encoder  410  and the decoder  450  are the same device or operably connected to the same device. 
     The encoder  410  receives media content from another device such as a server (similar to the server  104  of  FIG. 1 , the server  200  of  FIG. 2 ) or an information repository (such as a database). The encoder  410  can encode an atlas track corresponding to a PCC component, encode the PCC component in a first component track that references the atlas track, encode an alternative version of the PCC component from the first component track in a second component track, and transmit a compressed bitstreams including the atlas track, the first component track, and the second component track. The encoder  410  transmits frames representing the media content as an encoded bitstream. The bitstream can be transmitted to an information repository (such as a database) or an electronic device that includes a decoder (such as the decoder  450 ), or the decoder  450  itself through the network  402 . 
     The decoder  450  can receive a bitstream that represents media content. In certain embodiments, the decoder  450  can identify an atlas track corresponding to a PCC component, identify a set of first component tracks that is referenced by the atlas track and at least one second component track, where each of the at least one second component track is an alternative version of a first component track of the set of first component tracks, determine which of the set of first component tracks and the at least one second component tracks are appropriate versions of the PCC component, and decode the appropriate version of the PCC component from among the set of first component tracks and the at least one second component track. 
     Although  FIG. 4  illustrates examples of an encoder and a decoder, various changes can be made to  FIG. 4 . For example, various components in  FIG. 4  could be combined, further subdivided, or omitted and additional components could be added according to particular needs. As a particular example, the encoder  410  or decoder  450  could be divided into multiple components. In addition, as with computing and communication, encoders and decoders can come in a wide variety of configurations, and  FIG. 4  does not limit this disclosure to any particular encoder or decoder. 
       FIGS. 5A through 5C  illustrates an example files  500 ,  502 ,  504  in accordance with this disclosure. In particular,  FIG. 5A  illustrates file  500 ,  FIG. 5B  illustrates file  502 , and  FIG. 5C  illustrates file  504 . The embodiments of the files  500 ,  502 ,  504  illustrated in  FIGS. 5A through 5C  are for illustration only.  FIGS. 5A through 5C  do not limit the scope of this disclosure to any particular implementation of an electronic device. 
     As shown in  FIGS. 5A through 5C , the file  500  can include at atlas track  506  and a plurality of component tracks  508 . More than one version of a component can be stored in a video-based PCC (V-PCC) file  500 . Decoding can begin from at an atlas track  506  and the file  500  can include a combination of atlas tracks  506  and component tracks  508 . An atlas track  506  is a first track read for processing of a PCC component. For decoding a PCC component, an atlas track  506  and the corresponding component tracks  508  associated with the atlas track  506  are decoded. The term “atlas” can be interchangeable with “patches”. A single atlas track  506  can be used per V-PCC objects, where an atlas track  506  includes a group of patches. A file  500  can include multiple atlas tracks  506  when atlas tracks  506  contain totally different objects or differently encoded versions of an object. 
     Track alternatives are indicated by the alternate track mechanism defined in ISO/IEC 14496-12 (i.e., alternate_group field of the TrackHeaderBox). V3C content can have many versions. In certain embodiments, tracks including V3C contents in alternative relationship have the same alternate_group value  512  in their TrackHeaderBox. A single V3C content may have alternative representation of V3C video components. V3C video component tracks  508  that have the same alternate_group value  512  are different representations of the same V3C video component. 
     When V3C content has alternatives, more than two V3C contents in an alternative relationship are not to be played together, which means that one of the two V3C contents does not need to be processed. All V3C video component tracks  508  that include V3C contents in alternative relationship shall be referenced by one and only one V3C atlas track or V3C atlas tile track. When V3C content have alternatives in a file  500 , a sample entry of component tracks  508  belonging to the V3C content in alternative relationships may not provide enough information to show the differences between the alternative versions. The application may use additional external mechanisms, e.g. DASH 1MPD, scene descriptions, and so on, to get information to select one appropriate version for play. 
     When a V3C video component track  508  has alternatives versions, only one of the V3C video component tracks  508  that belong to a same alternative group is referenced by the V3C atlas track  506  or V3C atlas tile track  520 . V3C video component tracks  508  not directly referenced by the V3C atlas track  506  or V3C atlas tile track  520  are also represented as restricted video and have a generic restricted sample entry ‘resv’ with additional requirements. When a V3C video component track  508  has alternatives, a sample entry of each alternative component track  508  provides enough information to show the differences between the alternative representations in order to select one appropriate representation for playing by the application. 
       FIG. 5A  shows an example of a V3C content using track alternatives of V3C video components tracks  508 . A scheme type value  514  for the component tracks  508  with a track ID value  516  within the range of  2  and  8 , ‘vvvc’ indicates they are the V3C video components tracks. The component tracks  508  with a track ID value  516  of  2 ,  3 , and  4  are known as the V3C video component track  508  related to the V3C atlas track  506  with track ID value  516  of  1 . The relationship between the components tracks  508  related to the atlas track  506  is included in information of the atlas track  506  that directly lists the component track  508 . Even though the component tracks  508  with track ID values  516  of  5 ,  6 ,  7 , and  8  are not directly listed, these component tracks  508  are also identified as V3C video component tracks  508  related to the same V3C atlas track  506  by having same alternative group value  512  of track alternative group information with the component tracks  508  with track ID values  516  of  2 ,  3 , and  4 . The component tracks  508  with the alternate group values  512  of  10 ,  11 , and  12 , respectively, are the alternative representations for the same components of V3C content. The original format value  518  in RestrictedSchemeInfoBox shows that the component tracks  508  with a track ID value  516  of  2 ,  3 , and  4  are AVC encoded representations and the component tracks  508  with track ID values  516  of  5 ,  6 , and  7  are HEVC encoded alternative representations of the component tracks  508  with track ID value of  2 ,  3  and  4 , respectively. The original format value  518  in RestrictedSchemeInfoBox shows that the component tracks  508  with a track ID value  516  of  8  is a VVC encoded alternative representation of the component tracks  508  with a track ID value  516  of  4  and  7 . 
     As shown in  FIG. 5B , file  502  includes V3C content that uses track alternatives of V3C video components tracks  508  with V3C atlas tile tracks  520 . The scheme type value  514  of the component tracks  508  with track ID values  516  within the range between 21 and 28 are set to ‘vvvc’, which indicates the component tracks  508  are V3C video components tracks. The track reference information in the V3C atlas tile tracks  520  show that the component tracks  508  with track ID values  516  of  21 ,  22  and  23  are V3C video components tracks  508  related to V3C atlas tile track  520  with a track ID value  516  of  11  and the component tracks  508  with track ID values  516  within the range between 24, 25 and 26 are V3C video components tracks  508  related to V3C atlas tile track  520  with track ID value  516  of  12 . Based on the alternate group value  512 , the component tracks  508  with track ID values  516  of  27  and  28  are identified as the alternative representation  522  of the component track  508  with a track ID value  516  of  24  and  25 , respectively, which means that they are also the V3C component tracks  508  related to the V3C atlas track  506  with track ID value  516  of  12 . The original format value  518  in RestrictedSchemeInfoBox shows that the component tracks  508  with a track ID value of  24  and  25  are AVC encoded representations and the component tracks  508  with a track ID value  516  of  27  and  28  are HEVC encoded alternative representations  522  of the component tracks  508  with a track ID value  516  of  24  and  25 , respectively. 
     As shown in  FIG. 5C , file  504  includes V3C contents that can have alternative representations  522 . The component tracks  508  with track ID values  516  in the range between 1 and 4 comprises one V3C content and the component tracks  508  with track ID value  516  in the range between 10 and 18 comprises other V3C content. Two V3C atlas tracks  506  with a same alternative group value  512  indicates that the V3C contents included in each of the V3C atlas tracks  506  are alternatives to each other. In certain embodiments, the V3C content with V3C atlas track  506  with a track ID value  516  of  1  is a version that does not use the V3C atlas tile mechanism. The V3C content with V3C atlas track  506  with a track ID value  516  of  10  is a version that uses the V3C atlas tile mechanism. For the V3C video component tracks  508 , the scheme type value  514  of the component tracks  508  is ‘vvvc.’ The V3C video component tracks  508  are directly referenced by either V3C atlas track  506  or V3C atlas tile tracks  520 . The track reference information in the V3C atlas tracks  506  with a track ID value of  1  shows that the component tracks  508  with track ID values  516  of  2 ,  3  and  4  are the V3C video components tracks  508  in the atlas track  506 . The track reference information in the V3C atlas tile tracks  520  show that the component tracks  508  with a track ID value  516  of  13 ,  14  or  15  are the V3C video components tracks related to V3C atlas tile track  520  with a track ID value  516  of  11  and the component tracks  508  with track ID values  516  of  16 ,  17  or  18  are the V3C video components tracks  508  related to V3C atlas tile track  520  with a track ID value  516  of  12 . All the V3C video component tracks  508  are referenced by a single V3C atlas track  506  or a single V3C atlas tile track  520 . 
     For DASH 1MPD with video component alternatives, the value of @codecs parameter of the AdapationSet element for each video components shall be set to ‘resv.vvvc.XXXX’, where XXXX corresponds to the four-character code (4CC) of the video codec from the original format value  518  in RestrictedSchemeInfoBox of Sample Entry (e.g., ‘avcl’ or ‘hvcl’). 
     For DASH MPD, v3c:@atlas_id and VideoComponent@atlas_id, the parameter indicates the atlas id of the component track  508  carried by the adaptation set, which is present if multiple versions of the same volumetric media are signalled in separate adaptation sets, i.e. V3C content alternatives are presented, and video components associated to each versions of the are also signalled in separate adaptation sets. 
     As shown in  FIG. 5C , file  504  includes two V3C contents that have alternative representations  522 . There are thirteen adaptation sets. As adaptation set  524  does not have atlas tile encoding and adaptation set  526  does has atlas tile, the adaptation sets  524 ,  526  are encoded as alternatives  528 . However, adaptation sets  524  and  526  are defined as individual adaptation sets. Two atlas tile tracks are also defined as individual adaptation sets as they are alternatives each other. As the video component tracks  508  associated to the atlas track  506  without atlas tile encoding in adaptation set  524  are alternatives  528  to the video components tracks  508  associated to the atlas track  520  with atlas tile encoding in adaptation set  526 . All three component tracks  508  are defined as individual adaptation sets. All video component tracks  508  associated with atlas tile tracks  520  are defined as individual adaptation sets. Atlas tile preselection is used to indicate alternative relationship of video components associated each atlas tile tracks  520 . A same value of vID is assigned to both atlas tracks  506  as they are representing same V3C content and alternative each other. The atlasId parameter is provided to each adaptation sets for atlas tracks as they are alternative relationship each other. As the video component tracks are part of different versions of V3C content, adaptation sets for the video component tracks also have an atlas Id parameter to reference an associated atlas track so that relationship of video component tracks and atlas track can be known. 
     
       
         
           
               
             
               
                   
               
             
            
               
                 &lt;?xml version=“1.0” encoding=“UTF-8”?&gt; 
               
               
                 &lt;MPD 
               
               
                  xmlns=“urn:mpeg:dash:schema:mpd:2011” 
               
               
                  xmlns:v3c=“urn:mpeg:mpegI:v3c:2020” 
               
               
                  type=“static” 
               
               
                  mediaPresentationDuration=“PT10S” 
               
               
                  minBufferTime=“PT1S” 
               
               
                  profiles=“urn:mpeg:dash:profile:isoff-on-demand:2011”&gt; 
               
               
                 &lt;Period&gt; 
               
               
                  &lt;!-- Main V3C AdaptationSet --&gt; 
               
               
                  &lt;AdaptationSet id=“1” codecs=“v3c1”&gt; 
               
               
                   &lt;!-- V3C Descriptor --&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” 
               
               
                 Id=“1” atlasId=“1” /&gt; 
               
               
                   &lt;Representation id=“1”&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Atlas Adaptation Set 1 --&gt; 
               
               
                  &lt;AdaptationSet id=“2” codecs=“v3c1”&gt; 
               
               
                   &lt;!-- V3C Descriptor --&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” 
               
               
                 atlasId=“2” /&gt; 
               
               
                   &lt;Representation id=“2”&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Atlas Tile Adaptation Set 1 --&gt; 
               
               
                  &lt;AdaptationSet id=“3” codecs=“v3t1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” tiles=“1 2 3” /&gt; 
               
               
                   &lt;Representation dependencyId=“2”&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Atlas Tile Adaptation Set 2 --&gt; 
               
               
                  &lt;AdaptationSet id=“4” codecs=“v3t1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” tiles=“4 5 6”/&gt; 
               
               
                   &lt;Representation dependencyId=“2”&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Occupancy --&gt; 
               
               
                  &lt;AdaptationSet id=“5” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“occp” atlasId=“1” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“6” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“occp” atlasId=“2” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“7” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“occp” atlasId=“2” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Geometry --&gt; 
               
               
                  &lt;AdaptationSet id=“8” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“geom” atlasId=“1” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“9” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“geom” atlasId=“2” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“10” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“geom” atlasId=“2” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Attribute --&gt; 
               
               
                  &lt;AdaptationSet id=“11” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“attr” atlasId=“1” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“12” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“attr” atlasId=“2” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“13” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty chemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“attr” atlasId=“2” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Atlas Tile Preselections --&gt; 
               
               
                  &lt;Preselection id=“1” tag=“1” preselectionComponents=“2 6 9 12” codecs=“v3t1”&gt; 
               
               
                   &lt;!-V3C Descriptor --&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” /&gt; 
               
               
                  &lt;/Preselection&gt; 
               
               
                  &lt;Preselection id=“2” tag=“2” preselectionComponents=“3 7 10 13” codecs=“v3t1”&gt; 
               
               
                   &lt;!-V3C Descriptor --&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” Id=“1” /&gt; 
               
               
                  &lt;/Preselection&gt; 
               
               
                 &lt;/Period&gt; 
               
               
                 &lt;/MPD&gt; 
               
               
                   
               
            
           
         
       
     
     For DASH MPD, v3c:@alt_id and VideoComponent@alt_id, the parameter indicating an alternative version of a V3C content carried by the adaptation set is present if multiple versions of same volumetric media are signalled in separate adaptation sets. For example when V3C content alternatives are presented, video components associated to each versions of the are also signalled in separate adaptation sets. Below is Table 1 for elements and attributes for the V3C video component descriptor. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Elements and attributes for the V3C video component descriptor. 
               
            
           
           
               
               
               
               
            
               
                 Elements and attributes 
                 Use 
                 Data type 
                 Description 
               
               
                   
               
               
                   videoComponent@ alt_id 
                 CM 
                 xs:integer 
                 Indicates the id of the alternative 
               
               
                   
                   
                   
                 representation of a V3C Content the 
               
               
                   
                   
                   
                 component represented by the Adaptation 
               
               
                   
                   
                   
                 Set is comprising. This attribute shall be 
               
               
                   
                   
                   
                 present if multiple versions of same 
               
               
                   
                   
                   
                 volumetric media are signalled in separate 
               
               
                   
                   
                   
                 Adaptation Sets and video components 
               
               
                   
                   
                   
                 associated to each versions of the are also 
               
               
                   
                   
                   
                 signalled in separate Adaptation Sets. 
               
               
                   
               
               
                 Key: 
               
               
                 For attributes: M = Mandatory, O = Optional, OD = Optional with Default Value, CM = Conditionally Mandatory. 
               
               
                 For elements: &lt;minOccurs&gt; . . . &lt;maxOccurs&gt; (N = unbounded) 
               
               
                 Elements are bold; attributes are non-bold and preceded with an @. 
               
            
           
         
       
     
     Below is Table 2 for attributes for the V3C descriptor. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Attributes for the V3C descriptor 
               
            
           
           
               
               
               
               
            
               
                 Attributes 
                 Use 
                 Data type 
                 Description 
               
               
                   
               
               
                 v3c:@alt_id 
                 CM 
                 xs:integer 
                 Indicates the id of the alternative representation of a 
               
               
                   
                   
                   
                 V3C Content the atlas represented by the Adaptation Set 
               
               
                   
                   
                   
                 is comprsing. This attribute shall be present if multiple 
               
               
                   
                   
                   
                 versions of same volumetric media are signalled in 
               
               
                   
                   
                   
                 separate Adaptation Sets 
               
               
                   
               
               
                 Key: 
               
               
                 For attributes: M = Mandatory, O = Optional, OD = Optional with Default Value, CM = Conditionally Mandatory. 
               
               
                 For elements: &lt;minOccurs&gt; . . . &lt;maxOccurs&gt; (N = unbounded) 
               
               
                 Elements are bold; attributes are non-bold and preceded with an @. 
               
            
           
         
       
     
     This embodiment describes the case of file  504  with two V3C contents in alternative relationship as depicted in  FIG. 5C . There are thirteen adaptation sets. There are two atlas adaptation sets. The same value of vID is assigned to both atlas tracks  506  as they are representing the same V3C content and are alternatives to each other. As the tile track without atlas tile encoding and the tile track with atlas tile encoding are alternatives to each other, the tile tracks are defined as individual adaptation sets and different values are assigned to the @alt_id attribute. Two atlas tile tracks are also defined as individual adaptation sets as they are alternatives each other. The Alternative relationship of the atlas tile adaptation sets are indicated by having same value of @dependencyId. As the video component tracks associated to the atlas track without atlas tile encoding are alternatives to the video components tracks associated to the atlas track with atlas tile encoding, video component tracks are defined as individual adaptation sets. As the video component tracks are part of different version of V3C content, adaptation sets for the video component tracks also have alt_id parameter to reference atlas track associated with so that relationship of video component tracks and atlas track can be known. All video component tracks associated with atlas tile tracks are defined as individual adaptation sets. For the representation atlas tile encoding is used, more than one video components with same @type value are assigned with same value of @alt_id. Preselection is provided to describe the relationship between the atlas tile adaptation sets and the video component adaptation sets. 
     
       
         
           
               
             
               
                   
               
             
            
               
                  &lt;?xml version=“1.0” encoding=“UTF-8”?&gt; 
               
               
                 &lt;MPD 
               
               
                  xmlns=“urn:mpeg:dash:schema:mpd:2011” 
               
               
                  xmlns:v3c=“urn:mpeg:mpegI:v3c:2020” 
               
               
                  type=“static” 
               
               
                  mediaPresentationDuration=“PT10S” 
               
               
                  minBufferTime=“PT1S” 
               
               
                  profiles=“urn:mpeg:dash:profile:isoff-on-demand:2011”&gt; 
               
               
                 &lt;Period&gt; 
               
               
                  &lt;!-- Main V3C AdaptationSet --&gt; 
               
               
                  &lt;AdaptationSet id=“1” codecs=“v3c1”&gt; 
               
               
                    &lt;!-- V3C Descriptor --&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” 
               
               
                 vId=“1” alt_id=“1” /&gt; 
               
               
                    &lt;Representation id=“1”&gt; 
               
               
                     ... 
               
               
                    &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                   &lt;!-- Atlas Adaptation Set 1 --&gt; 
               
               
                  &lt;AdaptationSet id=“2” codecs=“v3c1”&gt; 
               
               
                    &lt;!-- V3C Descriptor --&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” 
               
               
                 vId=“1” alt_id =“2” /&gt; 
               
               
                    &lt;Representation id=“2”&gt; 
               
               
                     ... 
               
               
                    &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                   &lt;!-- Atlas Tile Adaptation Set 1 --&gt; 
               
               
                  &lt;AdaptationSet id=“3” codecs=“v3t1”&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” 
               
               
                 tile_ids=“1 2 3” /&gt; 
               
               
                    &lt;Representation dependencyId=“2”&gt; 
               
               
                     ... 
               
               
                    &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Atlas Tile Adaptation Set 2 --&gt; 
               
               
                  &lt;AdaptationSet id=“4” codecs=“v3t1”&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” 
               
               
                 tile_ids=“4 5 6”/&gt; 
               
               
                    &lt;Representation dependencyId=“2”&gt; 
               
               
                     ... 
               
               
                    &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Occupancy --&gt; 
               
               
                  &lt;AdaptationSet id=“5” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                    &lt;EssentialProperty 
               
               
                 schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                     &lt;v3c:videoComponent type=“occp” alt_id =“1” /&gt; 
               
               
                    &lt;/EssentialProperty&gt; 
               
               
                    &lt;Representation&gt; 
               
               
                     ... 
               
               
                    &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“6” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                    &lt;EssentialProperty 
               
               
                 schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                     &lt;v3c:videoComponent type=“occp” alt_id =“2” tile_ids=“1 2 3” /&gt; 
               
               
                    &lt;/EssentialProperty&gt; 
               
               
                    &lt;Representation&gt; 
               
               
                     ... 
               
               
                    &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                   &lt;AdaptationSet id=“7” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                    &lt;EssentialProperty 
               
               
                 schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                     &lt;v3c:videoComponent type=“occp” alt_id =“2” tile_ids=“4 5 6”/&gt; 
               
               
                    &lt;/EssentialProperty&gt; 
               
               
                    &lt;Representation&gt; 
               
               
                     ... 
               
               
                    &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Geometry --&gt; 
               
               
                  &lt;AdaptationSet id=“8” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                    &lt;EssentialProperty 
               
               
                 schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                     &lt;v3c:videoComponent type=“geom” alt_id =“1” /&gt; 
               
               
                    &lt;/EssentialProperty&gt; 
               
               
                    &lt;Representation&gt; 
               
               
                     ... 
               
               
                    &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“9” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                    &lt;EssentialProperty 
               
               
                 schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                     &lt;v3c:videoComponent type=“geom” alt_id =“2” tile_ids=“1 2 3” 
               
               
                 /&gt; 
               
               
                    &lt;/EssentialProperty&gt; 
               
               
                    &lt;Representation&gt; 
               
               
                     ... 
               
               
                    &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                   &lt;AdaptationSet id=“10” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                    &lt;EssentialProperty 
               
               
                 schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                     &lt;v3c:videoComponent type=“geom” alt_id =“2” tile_ids=“4 5 6”/&gt; 
               
               
                    &lt;/EssentialProperty&gt; 
               
               
                    &lt;Representation&gt; 
               
               
                     ... 
               
               
                    &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Attribute --&gt; 
               
               
                  &lt;AdaptationSet id=“11” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                    &lt;EssentialProperty 
               
               
                 schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                     &lt;v3c:videoComponent type=“attr” alt_id=“1” /&gt; 
               
               
                    &lt;/EssentialProperty&gt; 
               
               
                    &lt;Representation&gt; 
               
               
                     ... 
               
               
                    &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“12” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                    &lt;EssentialProperty 
               
               
                 schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                     &lt;v3c:videoComponent type=“attr” alt_id =“2” tile_ids=“1 2 3” /&gt; 
               
               
                    &lt;/EssentialProperty&gt; 
               
               
                    &lt;Representation&gt; 
               
               
                     ... 
               
               
                    &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                   &lt;AdaptationSet id=“13” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                    &lt;EssentialProperty 
               
               
                 schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                     &lt;v3c:videoComponent type=“attr” alt_id =“2” tile_ids=“4 5 6”/&gt; 
               
               
                    &lt;/EssentialProperty&gt; 
               
               
                    &lt;Representation&gt; 
               
               
                     ... 
               
               
                    &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Atlas Tile Preselections --&gt; 
               
               
                  &lt;Preselection id=“1” tag=“1” preselectionComponents=“2 6 9 12” codecs=“v3t1”&gt; 
               
               
                    &lt;!-V3C Descriptor --&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” 
               
               
                 vId=“1” /&gt; 
               
               
                  &lt;/Preselection&gt; 
               
               
                  &lt;Preselection id=“2” tag=“2” preselectionComponents=“3 7 10 13” codecs=“v3t1”&gt; 
               
               
                    &lt;!-V3C Descriptor --&gt; 
               
               
                    &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” 
               
               
                 vId=“1” /&gt; 
               
               
                  &lt;/Preselection&gt; 
               
               
                 &lt;/Period&gt; 
               
               
                 &lt;/MPD&gt; 
               
               
                   
               
            
           
         
       
     
     For DASH MPD, v3c:@vId, v3c:@atlas_id and VideoComponent@atlas_id, the parameter indicating an alternative version of a V3C content carried by the adaptation set is present if multiple versions of same volumetric media are signalled in separate adaptation sets. For example, when V3C content alternatives are presented, video components associated to each versions of the are also signalled in separate adaptation sets. The atlas tracks are signalled in separate adaptation sets. For the atlas tile tracks not using atlas tile encoding, separate preselections including each of such atlas adaptation sets are defined to indicate the video component tracks associated with each atlas tracks. The atlas tile tracks using atlas tile encoding are not directly included in any preselection but the preselection for each atlas tile tracks are defined to indicate the video component tracks associated with each atlas tile tracks. Through the dependency relationship between the atlas tile track and the atlas track that comprises one of alternative representations of a V3C content, it can be known that the atlas tile tracks are part of one alternative representations of a V3C content indirectly. 
     This embodiment describes the case of two V3C contents in an alternative relationship as depicted in the  FIG. 5C . There are thirteen adaptation sets. There are two atlas adaptation sets. The same value of @vID and @atlas_id is assigned to both atlas tracks as they are representing the same V3C content and are alternative to each other. As the tile track without atlas tile encoding and the tile track with atlas tile encoding are alternatives each other, the tile tracks are defined as individual adaptation sets and the same values are assigned for the @atlas_id attribute. Two atlas tile tracks are also defined as individual adaptation sets as they are alternatives each other. Component alternative relationship of the atlas tile adaptation sets are indicated by having same value of @dependencyId. All video component tracks associated with atlas tile tracks are defined as individual adaptation sets. Atlas tile preselection is used to indicate alternative relationship of video components associated each atlas tile tracks. Two preselections to indicate the video components for each atlas tile tracks are defined. As there are two atlas tracks with the same value of @vID and @atlas_id, the client can understand that there are two alternative versions of an V3C content. As one of the preselections includes one of the atlas adaptations set, the client can understand that such preselection defines one representation of the V3C content. As two preselection includes the atlas tile adaptation sets and the atlas tile adaptation sets are dependent on the atlas tile track, which is not part of any preselection, then the client can understand that such preselections are part of another representation of the V3C content using the atlas tile track. 
     
       
         
           
               
             
               
                   
               
             
            
               
                 &lt;?xml version=“1.0” encoding=“UTF-8”?&gt; 
               
               
                 &lt;MPD 
               
               
                  xmlns=“urn:mpeg:dash:schema:mpd:2011” 
               
               
                  xmlns:v3c=“urn:mpeg:mpegI:v3c:2020” 
               
               
                  type=“static” 
               
               
                  mediaPresentationDuration=“PT10S” 
               
               
                  minBufferTime=“PT1S” 
               
               
                  profiles=“urn:mpeg:dash:profile:isoff-on-demand:2011”&gt; 
               
               
                 &lt;Period&gt; 
               
               
                  &lt;!-- Main V3C AdaptationSet 1 --&gt; 
               
               
                  &lt;AdaptationSet id=“1” codecs=“v3c1”&gt; 
               
               
                   &lt;!-- V3C Descriptor --&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” 
               
               
                 atlas_id=“1” /&gt; 
               
               
                   &lt;Representation id=“1”&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                 &lt;!-- Main V3C AdaptationSet 2 --&gt; 
               
               
                  &lt;AdaptationSet id=“2” codecs=“v3c1”&gt; 
               
               
                   &lt;!-- V3C Descriptor --&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” 
               
               
                 atlas_id=“1”/&gt; 
               
               
                   &lt;Representation id=“2”&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                 &lt;!-- Atlas Tile Adaptation Set 1 --&gt; 
               
               
                  &lt;AdaptationSet id=“3” codecs=“v3t1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” tile_ids=“1 2 3” /&gt; 
               
               
                   &lt;Representation dependencyId=“2”&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Atlas Tile Adaptation Set 2 --&gt; 
               
               
                  &lt;AdaptationSet id=“4” codecs=“v3t1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” tile_ids=“4 5 6”/&gt; 
               
               
                   &lt;Representation dependencyId=“2”&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Occupancy --&gt; 
               
               
                  &lt;AdaptationSet id=“5” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“occp” atlas_id=“1”/&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“6” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“occp” atlas_id=“1” tile_ids=“1 2 3” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“7” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“occp” atlas_id=“1” tile_ids=“4 5 6” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Geometry --&gt; 
               
               
                  &lt;AdaptationSet id=“8” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“geom” atlas_id=“1”/&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“9” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“geom” atlas_id=“1” tile_ids=“1 2 3” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“10” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“geom” atlas_id=“1” tile_ids=“4 5 6” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Attribute --&gt; 
               
               
                  &lt;AdaptationSet id=“11” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“attr” atlas_id=“1” tile_ids=“4 5 6” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“12” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“attr” atlas_id=“1” tile_ids=“1 2 3” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;AdaptationSet id=“13” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” /&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”&gt; 
               
               
                    &lt;v3c:videoComponent type=“attr” atlas_id=“1” tile_ids=“4 5 6” /&gt; 
               
               
                   &lt;/EssentialProperty&gt; 
               
               
                   &lt;Representation&gt; 
               
               
                    ... 
               
               
                   &lt;/Representation&gt; 
               
               
                  &lt;/AdaptationSet&gt; 
               
               
                  &lt;!-- Atlas Tile Preselections --&gt; 
               
               
                  &lt;Preselection id=“1” tag=“1” preselectionComponents=“1 5 8 11” codecs=“v3c1”&gt; 
               
               
                   &lt;!-V3C Descriptor --&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” 
               
               
                 atlas_id=“1”/&gt; 
               
               
                  &lt;/Preselection&gt; 
               
               
                  &lt;Preselection id=“2” tag=“2” preselectionComponents=“3 6 9 12” codecs=“v3t1”&gt; 
               
               
                   &lt;!-V3C Descriptor --&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” 
               
               
                 atlas_id=“1”/&gt; 
               
               
                  &lt;/Preselection&gt; 
               
               
                  &lt;Preselection id=“3” tag=“3” preselectionComponents=“4 7 10 13” codecs=“v3t1”&gt; 
               
               
                   &lt;!-V3C Descriptor --&gt; 
               
               
                   &lt;EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” 
               
               
                 atlas_id=“1”/&gt; 
               
               
                  &lt;/Preselection&gt; 
               
               
                 &lt;/Period&gt; 
               
               
                 &lt;/MPD&gt; 
               
               
                   
               
            
           
         
       
     
     Although  FIGS. 5A through 5C  illustrate files  500 ,  502 ,  504 , various changes may be made to  FIGS. 5A through 5C . For example, the sizes, shapes, and dimensions of the files  500 ,  502 ,  504  and each file&#39;s individual components can vary as needed or desired. Also, the number and placement of various components of the files  500 ,  502 ,  504  can vary as needed or desired. In addition, the files  500 ,  502 ,  504  may be used in any other suitable media processing process and is not limited to the specific processes described above. 
       FIG. 6  illustrates an example method  600  for V3C video component track alternatives according to this disclosure. For ease of explanation, the method  600  of  FIG. 6  is described as being performed using the electronic device  300  of  FIG. 3 . However, the method  600  may be used with any other suitable system and any other suitable electronic device. 
     As shown in  FIG. 6 , the electronic device  300  can receive a plurality of tracks in a compressed bitstream at step  602 . The plurality of tracks can be received from an internal storage, such as memory  360 . The plurality of tracks can also be received wirelessly through a transceiver, such as transceiver  310 . The plurality of tracks can be received directly from an external device through an input, such as input  350 . 
     The electronic device  300  identifies an atlas track  506  corresponding to a PCC component at step  604 . The atlas track  506  can be a first track in a file  500 . The electronic device  300  can identify information in an atlas track that corresponds to the PCC component required for display to the user. 
     The electronic device  300  identifies a set of first component tracks that is referenced by the atlas track and at least one second component tracks, where each of the at least one second component track is an alternative version of a first component track of the set of first component tracks at step  606 . The atlas track  506  can include information that references one or more component tracks for PCC content. The at least one second component tracks are not directly referenced by the atlas track but have an indicator that matches one of the first component tracks. The indicator could be an alternate track value. Multiple tracks (more than two) could include the same alternate track value. Each of the tracks with the alternate track value or alternatives for the PCC component. Other information included in the alternative component tracks can be used to indicate a suitable version of the PCC component. For example, each of the alternative component tracks could include an original format value. The PCC component could use the original format value to determine the suitable version of the PCC component based on the encoding type. 
     Alternative component tracks could be included under alternative atlas tracks. Atlas tracks with a same alternate group value could indicate different versions of the same object, encoded similarly or differently. In other words, a PCC component could have characteristics that are different other than the encoding type. The alternate components could be different colors, orientations, etc. 
     The electronic device  300  determines which of the set of first component tracks and the at least one second component track are appropriate versions of the PCC component at step  608 . The electronic device  300  can determine the appropriate version based on the characteristics of the decoder, the requirements from the user, etc. The appropriate version is indicated through one or more of the values in the component track. 
     The electronic device  300  decodes the appropriate version of the PCC component from among the set of first component tracks and the at least one second component track at step  610 . The electronic device  300  decodes only the appropriate version of the PCC component, without processing any other of the alternative component tracks, alternative atlas tracks, or alternative atlas tile tracks. The PCC component can then be display appropriately to a user. 
     Although  FIG. 6  illustrates one example of a method  600  for V3C video component track alternatives, various changes may be made to  FIG. 6 . For example, while shown as a series of steps, various steps in  FIG. 6  may overlap, occur in parallel, or occur any number of times. 
     Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims. None of the description in this application should be read as implying that any particular element, step, or function is an essential element that must be included in the claims scope. The scope of patented subject matter is defined by the claims.