KR20220165693A - Method and apparatus for digital broadcast services - Google Patents

Abstract

A method of operating a receiving device in a multimedia system is disclosed. The method includes a step of receiving event information related to an event that includes a notification to an application, indicating that an action is to occur. When the event information indicates a first event for dynamic adaptive streaming over hypertext transfer protocol (DASH)-based services, the event information is received in a first event information box included in a media presentation description (MPD). When the event information indicates a second event for moving picture experts group media transport (MMT)-based services, the event information is received in a second event information box included in a media processing unit (MPU) in the MMT payload. If the event information indicates the second event for the MMT-based services, the event information includes a value of the event, an identifier (ID) of the event, a start time of the event, a duration of the event, and event data of the event. The present invention is to support an application program service.

Description

Digital broadcast service method and apparatus {METHOD AND APPARATUS FOR DIGITAL BROADCAST SERVICES}

The present invention relates to a method and apparatus for transmitting application program service information and events in a digital broadcast service.

The multimedia service refers to an interactive service such as a video phone, a streaming service such as a Video On Demand (VOD) service, or a multicast and broadcast service. Real-time multimedia services can be divided into interactive services, interactive services, and streaming services according to the type of service, and can also be divided into unicast, multicast, and broadcast according to the number of participating users.

MPEG-2 TS (Moving Picture Experts Group-2 Transport Stream) is a technology used to transmit multimedia contents. It is a bit stream in which a plurality of broadcast programs (a plurality of coded video bit streams) are multiplexed in a transmission environment with errors. It is used as a representative transmission technology for transmitting. As one of the multimedia transmission technologies for supporting multimedia services based on MPEG technology, the MMT (MPEG MEDIA Transport) standard has been proposed. MMT technology is a new standard technology of MPEG for smoothly providing various types of multimedia services through various user terminals such as TV (Television) or mobile devices in various types of network environments. For example, the MMT standard is a heterogeneous network It can be applied to efficiently transmit complex contents through. Here, the composite content refers to a set of content having multimedia elements such as video/audio/application. Also, the heterogeneous network may be, for example, a network in which a broadcasting network and a mobile communication network are mixed.

In order to support an application program service based on a hybrid transmission technology that organically interlocks a broadcast network and a communication network, in addition to receiving data or files necessary to execute an application program service using a broadcast network or a communication network, the terminal receives the application program Signaling information is needed to recognize and select services and related data. Therefore, there is a need for an effective signaling information transmission technology for providing application program services in a communication system using MPEG media transmission technology.

The present invention provides a method and apparatus for supporting a digital broadcasting service.

The present invention provides a method and apparatus for supporting an application program service that operates in conjunction with or independently of a broadcast program transmitted using media transmission technology.

The present invention provides a signaling information transmission method and apparatus for supporting an application program service for digital broadcasting service.

An object of the present invention is to devise a method and device for transmitting application program service related information and event information for controlling the operation of an application program service using MMT transmission technology.

A method of operating a receiving device in a multimedia system according to an embodiment of the present invention includes receiving event information related to an event including a notification to an application indicating that an action will occur, wherein the event information is DASH ( dynamic adaptive streaming over hypertext transfer protocol)-based services, the event information is received in a first event information box included in a media presentation description (MPD), and the event information is MMT ( When indicating a second event for moving picture experts group media transport)-based services, the event information is received in a second event information box included in a media processing unit (MPU) in the MMT payload, and the event information When the information indicates the second event for the MMT-based services, the event information includes a value for the event, an identifier (ID) of the event, a start time of the event, and a duration of the event. , and event data of the event.

A receiving device in a multimedia system according to an embodiment of the present invention; transceiver; and a controller coupled to the transceiver. The controller is configured to receive event information related to an event including a notification to an application indicating that an action is to occur, the event information indicating a first event for dynamic adaptive streaming over hypertext transfer protocol (DASH)-based services. When indicated, the event information is received within a first event information box included in a media presentation description (MPD), wherein the event information indicates a second event for moving picture experts group media transport (MMT)-based services. case, the event information is received in a second event information box included in a media processing unit (MPU) in the MMT payload, and the event information indicates the second event for the MMT-based services, The event information includes a value of the event, an identifier (ID) of the event, a start time of the event, a duration of the event, and event data of the event.

Also other aspects as described above, features and benefits of certain preferred embodiments of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings.
1 is a diagram showing a hierarchical structure of an MMT system according to an embodiment of the present invention.
2 is a schematic diagram of the configuration of an MMT payload according to an embodiment of the present invention.
3 shows a logical structure of an MMT package according to an embodiment of the present invention.
4 illustrates a schematic operation process of a terminal for executing an application program service according to an embodiment of the present invention.
5 is a schematic diagram of a device for receiving information related to an application program service according to an embodiment of the present invention.
6 is a flowchart illustrating a process of processing event information using an MMT signaling message according to an embodiment of the present invention.
7 is a flowchart illustrating a process of processing event information using an MPU according to an embodiment of the present invention.
It should be noted that throughout the drawings, like reference numbers are used to show the same or similar elements, features and structures.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted. This is to more clearly convey the gist of the present invention without obscuring it by omitting unnecessary description.

For the same reason, in the accompanying drawings, some components are exaggerated, omitted, or schematically illustrated. Also, the size of each component does not entirely reflect the actual size. In each figure, the same reference number is assigned to the same or corresponding component.

Advantages and features of the present invention, and methods for achieving them, will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the present embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

At this time, it will be understood that each block of the process flow chart diagrams and combinations of the flow chart diagrams can be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment are described in the flowchart block(s). It creates means to perform functions. These computer program instructions may also be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular way, such that the computer usable or computer readable memory The instructions stored in are also capable of producing an article of manufacture containing instruction means that perform the functions described in the flowchart block(s). The computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to generate computer or other programmable data processing equipment. Instructions for performing processing equipment may also provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is possible for the functions mentioned in the blocks to occur out of order. For example, two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in reverse order depending on their function.

At this time, the term '~unit' used in this embodiment means software or a hardware component such as a field-programmable gate array (FPGA) or application specific integrated circuit (ASIC), and what role does '~unit' have? perform them However, '~ part' is not limited to software or hardware. '~bu' may be configured to be in an addressable storage medium and may be configured to reproduce one or more processors. Therefore, as an example, '~unit' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Functions provided within components and '~units' may be combined into smaller numbers of components and '~units' or further separated into additional components and '~units'. In addition, components and '~units' may be implemented to play one or more CPUs in a device or a secure multimedia card.

In the detailed description of the embodiments of the present disclosure, the OFDM-based wireless communication system will be the main target, but the main subject matter to be claimed in this specification is disclosed in this specification to other communication systems and services having a similar technical background. It can be applied within a range that does not greatly deviate from the scope, and this will be possible with the judgment of a person skilled in the art.

The MMT Protocol (MMTP) defines an application layer protocol for transporting transport frames composed of an MMT Payload Format (PF) over an Internet Protocol (IP) network. The MMT payload is designed to be efficiently delivered in an MMT payload format. In order to efficiently deliver MPEG media data over heterogeneous IP networks, MMT defines encapsulation formats, delivery protocols, and signaling message formats.

MMT technology defines data models such as packages and assets. A package means one independent piece of content, such as a movie, and an asset is a logical entity that classifies elements such as video, audio, or data constituting the content, and one package may consist of a plurality of assets.

1 is a diagram showing a hierarchical structure of an MMT system according to an embodiment of the present invention.

Referring to FIG. 1, a media coding layer 110, an encapsulation function layer (Layer E) 120, and a delivery function layer for constructing and transmitting a multimedia data packet : Layer D) 130, transport protocol layer 140, Internet Protocol (IP) layer 150, and Control Function Layer (Layer C) 100 are shown.

According to an embodiment, the media encoding layer 110 and the encapsulation function layer 120 operate as a multimedia data generation unit that generates multimedia data according to multimedia contents and/or multimedia services. In addition, the delivery function layer 130 operates as a multimedia data configuration unit that configures multimedia data packets based on the multimedia data input from the data generation unit. The delivery function layer 130 corresponding to the multimedia data constructing unit identifies at least one piece of multimedia data provided from the multimedia data generating unit to construct header information, and configures a multimedia data packet by combining the header information and at least one multimedia data. do.

The multimedia data compressed in the media encoding layer 110 is packaged in a form similar to a file format through an encapsulation function layer 120 and output. The encapsulation function layer 120 takes the coded media data or stored media data provided from the media encoding layer 110 as an input and generates a data segment, which is a small unit for the MMT service, and uses the data segment to Create access units for MMT service. Also, the encapsulation function layer 120 creates a packet format for generating, storing, and transmitting complex content by combining and/or dividing the access units.

The delivery function layer 130 converts the data unit(s) output from the encapsulation function layer 120 into an MMT payload format, and then adds an MMT transport packet header to form an MMT transport packet, or Alternatively, it is composed of RTP packets using RTP (Real-time Protocol), an existing transmission protocol.

Packets constructed in the delivery function layer 130 pass through a transport protocol layer 140 such as User Datagram Protocol (UDP) or Transport Control Protocol (TCP), and finally are IP packetized in the Internet Protocol (IP) layer 150 and transmitted. do. The transport protocol layer 140 and the IP layer 150 may operate as a data transmission unit. The control function unit 100, which may be selectively present, generates control information or signaling information required for data transmission and transmits it in addition to data or transmits it through a separate signaling means.

The MMT payload format generated by the delivery function layer 130 defines the logical structure of media unit(s) to be delivered by the MMT protocol or RTP. The MMT payload is specified by a payload format for conveying an encapsulated data unit and other information by MMT layer protocols or other existing Application Transport Protocols. The MMT payload provides information on streaming and information on file transfer. In streaming, the data unit may be an MMT Media Fragment Unit (MFU) or an MMT Processing Unit (MPU). In the case of file delivery, data units may be MMT assets and MMT packages.

2 is a schematic diagram of the configuration of an MMT payload according to an embodiment of the present invention.

Referring to FIG. 2, the MMT payload 200 may include at least one of at least one MMT MFU 210, at least one MPU 230, at least one MMT asset 230, and an MMT package. there is.

The MFU 210 refers to a general container format including coded media data that can be independently processed by a media decoder independent of any specific media codec. MFU (210) is to represent a portion of the fragmented data of the MPU (220), and becomes the smallest unit that can be independently decoded. As an example, when encoding is performed using one frame as an access unit, the MFU 210 may be one video frame, and in other cases, one slice included in one frame.

The MPU 220 is a container format including one or more MFUs and additional delivery and processing related information, and may include various numbers of MFUs generated from a plurality of different access units. The MPU 220 means a coded media data unit that can be completely and independently processed by an MMT compliant entity, and has a specific size according to the application environment. For example, in the case of video, 1 GOP (Group of Picture). As an example, the MPU 220 may include a plurality of picture frames constituting 1 GOP (eg, 1 second video), and the MFU 220 may include each picture frame.

The MMT asset 230 is a data entity composed of one or more MPUs, and is the largest data unit to which the same Composition Information (CI) and transport characteristics are applied. to be. The MMT asset 230 includes only one type of data including packaged or multiplexed data. For example, at least a portion of an elementary stream (ES) of audio, at least a portion of an ES of video, an MPEG-U (User Interface) widget package, and an MPEG-2 At least a portion of a Transport Stream (TS), at least a portion of an MP4 (MPEG-4) file, and all or at least a portion of an MMT package may be each MMT asset 230 .

Here, the elementary stream (ES) is defined by a specific media codec, and may logically be one or more MMT assets. The MMT asset 230 supporting the layered codec and the multi-view codec may overlap with other MMT assets.

MMT Composition Information (MMT-CI) refers to information defining the spatial and temporal relationship of MMT assets, and MMT Transport Characteristics (MMT-TC) refers to MMT assets Defines the Quality of Service (QoS) required for the delivery of MMT-TC may be expressed as Asset Delivery Characteristics (ADC) for a specific delivery environment.

The MMT package 240 is defined as a collection of encoded media data and related information processed by an MMT compliant entity.

3 shows the logical structure of an MMT package according to an embodiment of the present invention. As shown, the MMT package 300 includes one or more MMT assets 320, MMT synthesis information 310, and MMT trans. It consists of one or more ADCs 330 representing port characteristics. The MMT package 240 includes descriptive information such as an identifier and locations of the MMT assets 320, and the MMT assets 320 in the MMT package 240 may be multiplexed or concatenated.

The processing of the MMT package 240 is applied in units of MPUs, and the MMT asset 320 is an aggregate of one or more MPUs having the same MMT asset ID, and the transport characteristics related to each MMT asset 320 are ADC ( 330). The ADC 330 may be used by an entity that packetizes the MMT package to configure parameters of the MMT payload and header information of the MMT packet.

Configuration information of the above package and information necessary for receiving and consuming it in a user terminal are transmitted through an MMT signaling message. The MMT signaling functional area defines message formats related to media consumption and media delivery. Messages related to media consumption provide information necessary for consuming transmitted media data, and are defined as follows.

A PA (Package Access) message similar to the PMT (Program Map Table) of MPEG-2 TS includes all information necessary for reproducing a transmitted package. The PA message is a message that must be transmitted first in order to receive and consume a package, and individual information can be updated as a separate message afterwards. The MPI (Media Presentation Information) message, which provides presentation information, is a composite information (CI) defined by ISO/IEC 23008-11 or a media presentation defined by ISO/IEC (International Organization for Standardization/International Electrotechnical Commission) 23009-1. It is used to transmit various presentation information such as Media Presentation Description (MPD). An MMT Package Table (MPT) message is a message that provides information about a package to be transmitted, and provides an ID of the package and asset information constituting the package. In addition, CRI (Clock Relation Information) messages to provide mapping information between Network Time Protocol (NTP) timestamps and MPEG-2's System Timing Clock (STC) for synchronization between assets and MPEG-2 ES, and for media consumption. A DCI (Device Capability Information) message providing necessary device capability information is defined.

In addition to the convergence of broadcasting and communications and the advancement of transmission networks, high-definition realistic broadcasting service technologies such as UHDTV (Ultra High-Definition Television), 3DTV (3-Dimension TV), and multi-view TV (Multi-view TV), various types of fixed and Innovative technologies that enable next-generation broadcasting and multimedia services, such as N-screen service technology to organically utilize portable multimedia devices, are continuously being introduced to the market. In particular, the application program service that provides various additional information in conjunction with broadcast programs or independently based on hybrid transmission technology that enables convergence multimedia services by organically linking broadcasting networks and communication networks, maximizes realism and realism. Along with the provision of video content, it is considered a key success factor for next-generation broadcasting services. Representative application program service models include viewer participation-type services (simple text messages, quizzes, polls, surveys, popularity votes), TV e-commerce (ticket reservations, auctions, electronic coupons, mobile downloads), weather, sports, and games. It includes application program services, portal services, and customized advertisements that can be provided independently of broadcasting programs, such as .

In order to support an application program service, signaling information for recognizing and selecting an application program service and related data in a terminal is required along with reception of data or files necessary to execute an application program service using a broadcast network or a communication network. There are two types of signaling information related to application program services. That is, the signaling information may be subdivided into signaling information providing overall properties of individual services, such as available application program service lists, application program service names, and transmission information, and event information controlling the operation of application program services. In particular, in the case of an application program service linked to a broadcast program, it is possible to provide more diverse and abundant broadcast services by transmitting event information together.

4 illustrates a schematic operation process of a terminal for executing an application program service according to an embodiment of the present invention. Here, an example of an application program service for a customized advertisement at a specific time in conjunction with a broadcasting program is illustrated.

Referring to FIG. 4, in step 405, the terminal receives and plays audio and video streams of a broadcast program (Show X in the illustrated example) requested by the user from a service provider, and in step 410, the terminal transmits the audio and video streams to the application program service. Signaling information about an application program service associated with the broadcast program is acquired through an application information stream, which is a channel that provides related signaling, and, if necessary, the application program service is executed using a broadcast network or a communication network. receive the necessary data. The signaling information and data may be collectively referred to as application information.

In step 415, while playing the broadcast program, the terminal receives event information transmitted through an event stream, which is a channel providing events, and performs an operation accordingly. In the illustrated example, the terminal receives event information about the execution of an application program service Y that provides additional information on a product being advertised at the middle of Show X, that is, at the start of an advertisement time. In step 420, the terminal executes the application program service Y (ie, advertisement service) based on the event information. When an end event of the application program service Y is received in step 425 after a certain period of time, the terminal terminates the service Y.

MMT technology defines various signaling messages related to media consumption and media delivery, but the main role of these signaling messages is to provide package configuration information and information necessary for receiving individual assets constituting the package. In particular, the MP (MMT Package) table used in the MPT message defines configuration information for each asset constituting the package and location information required to receive each asset. Additional information other than this basic information is provided using a descriptor, and the MPT message defines a container format capable of storing various descriptors.

MPEG CI information that can be used in the MPI table may include time information related to reproduction of the corresponding asset together with location information of an individual asset constituting a package on a logical screen of a terminal. However, the main purpose of MPEG CI is to provide control information for assets transmitted through MMT, and therefore, there are limitations in applying to application program services transmitted through a transport protocol other than MMT.

Hereinafter, a technique for transmitting event information for controlling the operation of the application program service and the related information of the application program service using the MMT transmission technology will be described.

5 is a schematic diagram of a device for receiving information related to an application program service according to an embodiment of the present invention.

Referring to FIG. 5, a data receiver 505 receives a packet transmitted through a communication network or a broadcast network using at least one of transport protocols such as MMT, ROUTE, and HTTP (Hyper Text Transfer Protocol). It may include at least one of MMT data receiver 510, ROUTE data receiver 515, HTTP data receiver 520, and other data receiver 525, and the control unit 500 transmits the received packet according to its type. It is delivered to the file data receiver 530, the media data receiver 540, or the signaling data receiver 550 in

The file data receiver 530 processes the packet transmitted from the data receiver 505 and transfers the data included in the packet to the file processor 535. For example, the file data receiver 530 receives an MMTP (MMT Protocol) packet transmitted in the GFD (Generic File Delivery) mode defined in MMT, reconstructs it into an MMTP payload, and delivers it to the file handler 535, or ROUTE After receiving a packet transmitted through one of various file transfer protocols including the file transfer protocol, desired data is extracted and transmitted to the file processor 535. The file processor 535 reconstructs individual files based on data received from the file data receiver 530 .

The media data receiver 540 and the media processor 545 are elements that process media data. For example, when media data is an MMT Processing Unit (MPU) defined in MMT, the media processor 545 may be a component that processes media data transmitted in the MPU mode of MMTP. At this time, the media data receiver 540 reconstructs the MMTP payload based on the MMTP packet received from the MMT data receiver 515 in the data receiver 505 to generate an MPU, and the media processor 545 transmits the MPU It plays a role of receiving and playing through the service indicator 570.

If the media data is transmitted via a file, the file handler 535 passes the media file to the media processor 545 and the media processor 545 plays the media file to the service indicator 570 . As another example, when media data conforms to the Dynamic Adaptive Streaming over HTTP (DASH) format defined in ISO/IEC 23009-1, the media processor 545 may be a component that processes media data transmitted through the ROUTE protocol. At this time, the media processor 545 processes the ROUTE packet received from the ROUTE data receiver 515 to generate a DASH segment, and the media processor 545 plays the received DASH segment to the service indicator 570. play a role

The media data receiver 540 generates the entire media file conforming to the ISO Base Media File Format (ISOBMFF), such as MPU or DASH segments, and then transfers the media file to the media processor 545, or reduces channel switching time. For this purpose, a part of the media file generated before the entire media file is generated may be transmitted to the media processor 545.

If the packet received from the data receiver 505 includes signaling information, the packet is transferred to the signaling data receiver 550 and used to reconstruct the signaling information. The reconstructed signaling information is delivered to the signaling processor 555, and an additional operation is performed according to the contents of the signaling information. For example, when signaling information is transmitted through MMTP, the signaling data receiver 550 receives an MMTP packet storing signaling information from the MMT data receiver 510 and reconstructs it into an MMTP payload, and the signaling processor 555 receives the MMTP packet Signaling information in the payload is parsed and required information is stored in the signaling information DB (DataBase) 560 . If the signaling information is included in a file and transmitted, the signaling processor 555 receives the file storing the signaling information from the file processor 535, parses the signaling information, and stores necessary information in the DB 560.

The signaling processor 555 interacts with other components based on the parsed signaling information to perform additional operations. For example, when signaling information related to an application program service is received, the signaling processor 555 transfers information necessary for receiving data necessary for execution of the application program service to the file data receiver 530 to obtain the related data. to receive

Event information related to control of application program service may be transmitted through a dedicated signaling channel or embedded in media data. For example, in the case of MMT, event information may be transmitted through a signaling message or inherent in an MPU storing media data. Similarly, in the case of DASH, signaling information may be included in a Media Presentation Description (MPD) or embedded in a DASH segment including media data and transmitted. Accordingly, the media data receiver 540 extracts the event-related information when it is embedded in the media data, delivers it to the signaling processor 555, and ultimately transfers it to the application program manager 565, so that the event-related information is transmitted to the application program. Used to control the operation of program services.

The application program manager 565 stores and manages overall information about application program services, manages the operation of individual application program services, and displays information about each application program service through the service indicator 570 . To this end, the application program manager 565 interacts with the signaling processor 555 and the file processor 535 to receive data and signaling information necessary for providing application program services.

Hereinafter, an operation of transmitting signaling information and event information related to an application program service will be described.

1) Transmission of signaling information related to application program service

Information related to the application program service includes main attributes of the application program service, such as the name, transmission method, and life cycle of the application program service.

As an embodiment, an AIT (Application Information Table) message, which is a signaling message transmitted through an MMT signaling session, may be used to transmit information related to an application program service. <Table 1> below shows an example of a format of an AIT message and an AI (Application Information) table included in the AIT message.

syntax number of bits format AIT_message { message_id 16 uimsbf version 8 uimsbf length 16 uimsbf extension { } message_payload { AI_table() } }

Here, the message_id field means the ID of the AIT message, the version field indicates the version of the AIT message, the length field is the byte size of the AIT message, and indicates the length from the next position of the length field to the end of the AIT message, AI_table() The field contains the AI table.

The AIT message may further include an identifier for identifying a service to which the AIT message is applied in the extension part. In addition, a 1-bit flag for indicating the presence or absence of a Uniform Resource Identifier (URI) for identifying the AIT message may be further included. When the 1-bit flag is on, a field representing the URI is further included in the AIT message. can be included

Information on all application program services included in the MMT package may be transmitted using one AI table (i.e., Complete AI Table) or divided into multiple AI tables (i.e., Subset AI Table) and transmitted. . In the latter case, each Subset AI table is included in an independent AIT message and transmitted.

Table 2 below shows an example of a detailed format of the AI table.

syntax value number of bits format AI_table { table_id 8 uimsbf version 8 uimsbf length N1 16 uimsbf reserved '1111' 4 bslbf AI_table_mode 2 uimsbf reserved '11' 2 bslbf AI_table_descriptors { AI_table_descriptor_length N2 16 uimsbf for (i = 0; i < N2; ++i) AI_table_descriptor_bytes 8 uimsbf } AI_count N3 8 uimsbf for (i = 0; i < N3; ++i) { application_attributes() } }

Here, the table_id field represents the ID of the AI table. The Complete AI table and the Subset AI table may have different table_ids. Values of table_id are assigned sequentially, so the number of the Subset AI table can be calculated from the table_id field. That is, the number of the Subset AI table is calculated as "table_id - table_id of the Base Subset AI table". Here, the Base Subset AI table refers to a Subset AI table numbered 0. Numbers 1 to 14 indicate other (non-base) Subset AI cables, and 15 indicates the Complete AI table.

The version field indicates the version of the AI table, and the new version of the AI table replaces the previous version of the AI table upon receipt. The version field can be interpreted the same as the MPI table of the existing MMT signaling table. (If table_id indicates a complete AI table, if Subset-0 AI table has the same version value as this field (when AI_table_mode is '1'), or if all AI table subsets with lower-subset number have the same version value as this field (when AI_table_mode is '0'), or if processing of the AI table subsets are independent (when AI_table_mode is '2'). If Subset-0 AI table has a newer version, all AI table subsets with higher subset number up to 14 previously stored within an MMT receiving entity are treated as outdated except for the case when AI_table_mode is independent mode. When the AI table subset number is not 0 and AI_table_mode is '1', the contents of the AI table subset with version different from that of subset-0 AI table stored in an MMT receiving entity shall be ignored. Also when the AI table subset number is not 0 and AI_table_mode is '0', the contents of the AI table subset with version different from that of lower-subset AI table subsets stored in an MMT receiving entity shall be ignored. It shall be modulo-256 incremented per version change.)

The length field is the byte size of the AI table and indicates the length from the position next to the length field to the end of the AI table.

The AI_table_mode field specifies a processing method of the divided AI table when the AI table is divided and transmitted, and is used in a manner similar to PI_mode of the MPI table among existing MMT signaling tables. (In "sequential_order_processing_mode" and with a non-zero subset number of this AI table, an MMT receiving entity shall receive all AT tables with lower subset number that have the same version as this AI table before it processes this AI table. For example, an MMT receiving entity can't process subset-3 AI table, if it have not received subset-2 AI table with the same version.In "order_irrelevant_processing_mode" and with the subset number of this AI table subset set to non-zero, an MMT receiving entity should process a AI table right after it receives the AI table as long as the subset-0 AI table stored in an MMT receiving entity has the same version as this AI table. tables are managed individually. Fragmented AI table is adapted in this mode).

Examples of values and descriptions used in the AI_table_mode field are shown in <Table 3>.

AI_table_mode Description 00 "sequential_order_processing_mode" 01 "order_irrelevant_processing_mode" 10 "independent_processing_mode" 11 Reserved

The AI_table_descriptor_bytes field is a descriptor of the AI table, the AI_count field represents the number of application program services included in the AI table, and the application_attributes() field represents attributes of each application program service.

As described above, the AI table may include various attributes related to application program services, and the corresponding attributes are included in the application_attributes() field. These attributes may include the name of the application program service, transmission information and priority of data related to the application program service. Table 4 below shows an example of application_attributes().

syntax Explanation application_attributes() { app_name Application program service name app_id Application program service ID related_MMT_assets_count The number of assets (N1) in the MMT package associated with the application program service. If set to 0, it is an application program service that can be executed independently without interlocking with the package. for (i = 0; i < N1; ++i) asset_id Asset ID application_transport_methods_count Number of data or file transfer methods required to run application program services (N2) for (i = 0; i < N2; ++i) application_transport Detailed information about the transmission of data or files related to application program services using broadcast networks or communication networks. application_priority Application program service priority application_control_code Application program service lifecycle (e.g., AutoStart/Present/Kill/Suspend/Prefetch/Destroy/Disabled, etc.). Meaning of life cycle according to ETSI TS 102 809 standard application_type Type of application program service AI_ descriptor_length for (i = 0; i < N6; ++i) AI_ descriptor_bytes Application program service descriptor } }

In an embodiment described below, information related to an application program service may be transmitted through an MPT message that is a signaling message related to an MMT package. Specifically, the MPT message includes a descriptor indicating whether an application program service exists in the MMT package. A terminal must receive an MPT message to play a broadcast service transmitted through MMT. Therefore, by including a descriptor for the presence or absence of an application program service in the MPT message, the terminal can more quickly check the existence of an application program service.

If it is determined through the MPT message that the application program service exists in the MMT package, the terminal can acquire detailed information related to the application program service by receiving the AIT message as described above. The MPT message may additionally include information to be preferentially provided to the terminal among information included in the AIT and transmitted as necessary, in addition to simply notifying only the presence or absence of the application program service. The information to be preferentially provided may be information helpful in improving the performance of the terminal or improving the quality of experience (QoE).

Table 5 below shows an example of a detailed format of application_service_descriptor, which is a descriptor that can be included in an MPT message.

syntax value number of bits format application_service_descriptor() { descriptor_tag 16 uimsbf descriptor_length 8 uimsbf application_service_available One bslbf }

Here, the descriptor_tag field represents a tag capable of identifying the inband_event_descriptor field, the descriptor_length field represents the size of the inband_event_descriptor field, and the application_service_descriptor field informs whether an application program service exists in the package. If the value of the application_service_descriptor field is 0, it means that there is no application program service, and if it is 1, it means that there is an application program service, and detailed information related to the application program service is transmitted through an AIT message.

2) Transmission of event information

Event information can be transmitted in two major ways depending on whether the occurrence time of a corresponding event can be known in advance in a broadcast program. First, a static event transmission method is used when the time when a specific event occurs is known in advance, such as in a recorded broadcast. Second, a dynamic event transmission method is used when the time when a specific event occurs is unknown, such as in a live broadcast. this is used Event information is notified to the application program service.

As an embodiment, the event information may be delivered through an MMT signaling message transmitted through an MMT signaling channel, that is, an Application Event Information (AEI) message. AEI messages can be used for both static and dynamic event transmission. In the case of a dynamic event, event information may be included in media data where the corresponding event occurs, that is, the MPU and transmitted.

<Table 6> and <Table 7> show an example of a detailed format of an MMT signaling message including event information, that is, an AEI message and an AE table included in the AEI message.

syntax number of bits format AEI_message { message_id 16 uimsbf version 8 uimsbf length 16 uimsbf extension { } message_payload { AE_table() } }

Here, the message_id field represents the ID of the AEI message, the version field represents the version of the AEI message, and the length field represents the byte size of the AEI message, representing the length from the position next to the length field to the end of the AEI message. The AE_table() field includes an AE table.

As an embodiment, the AEI message may further include an identifier for identifying a service to which the AEI message is applied in the extension part. In addition, a 1-bit flag for indicating the presence or absence of a URI for identifying the AEI message may be further included, and when the 1-bit flag is turned on, a field indicating a URI may be further included in the AEI message.

syntax value number of bits format AE_table { table_id 16 uimsbf version 8 uimsbf length 16 uimsbf reserved 111111 6 bslbf number_of_app_events N1 8 uimsbf for (i=0; i<N1;++i) { AE_descriptor() } }

Here, the table_id field represents the ID of the AE table. The version field represents the version of the AE table, and the length field represents the byte size of the AE table, from the position next to the length field to the end of the AE table. The number_of_app_events field indicates the number of events included in the AE table, and the AE_descriptor() field includes detailed information of each event.

Detailed information of the event is stored in the AE_descriptor() descriptor, and may include various information related to the event, such as an application program service ID associated with the event, time and period to which the event is applied, event operation, and the like. The following <Table 8> shows an example of AE_descriptor().

syntax value number of bits format AE_descriptor() { descriptor_tag 16 uimsbf descriptor_length 8 uimsbf application_identifier() scheme_id_uri_length N1 8 uimsbf for (i=0;i<N1;++i) scheme_id_uri_byte 8 uimsbf event_value_length N2 8 Uimsbf for (i=0;i<N2;++i) event_value_byte 8 uimsbf event_id 32 uimsbf event_presentation_time 64 uimsbf event_duration 32 uimsbf event_data }

Here, the descriptor_tag field means a tag capable of identifying AE_descriptor(), the descriptor_length field means the size of AE_descriptor(), and the application_identifier() field is a unique ID of an application to which an event is applied. The following <Table 9> shows an example of a detailed format of the application_identifier() field.

syntax number of bits format application_identifier() { organization_id 32 uimbsf application_id 16 uimbsf }

Here, the scheme_id_uri_length field represents the byte size of scheme_id_uri, the scheme_id_uri field defines the meaning and grammar of the value transmitted to the event_data field, the event_value_length field represents the byte size of the event_data field, and the event_value field represents an event value. The range and meaning of event values are determined by scheme_id_uri. The event_id field represents a unique ID of an event, the event_presentation_time field represents a media presentation time to which an event is applied, the event_duration field represents a media presentation time for which an event is valid, and the event_data field represents event content.

As an embodiment, event information may be delivered through media data.

In the MMT transport protocol, media data is included in the MPU and transmitted, and the MPU follows the ISOBMFF structure. Event information may be included in an evti box in the MPU, and an example of a detailed format of the evti box is as follows.

Box Type: "evti"

Container: MPU

Mandatory: No

Quantity: Zero or more

Syntax:

aligned (8) class EventInformationBox extends FullBox('evti', version=0, flags=0) {

string scheme_id_uri

string event_value

unsigned int(32) event_id

unsigned int(32) event_presentation_time_delta

unsigned int(32) event_duration

unsigned int(32) event_data

string application_identifier

}

Here, the scheme_id_uri field defines the meaning and grammar of values transmitted to the event_data field, and the event_value field includes event values. The range and meaning of event values are determined by scheme_id_uri. The event_id field represents a unique ID of an event, the event_presentation_time_delta field represents the difference between the playback time of the MPU and the media to which the event is applied, the event_duration field represents the playback time of media for which the event is valid, and the event_data field represents the content of the event. indicate The application_identifier field represents an ID of an application program service to which an event is applied.

As an embodiment, event information is transmitted through the MPU of a specific asset, and MMT signaling information may be used to inform that event information is inherent in the MPU of the asset. To this end, an MMT Package (MP) table that transmits MMT package information includes inband_event_descriptor, which is a descriptor used at the asset level. When the terminal receives inband_event_descriptor through the MP table and confirms that event information is embedded in the MPU of a specific asset and transmitted, it receives the MPU of the asset and extracts event information from the evti box in the MPU. Table 10 below shows an example of a detailed format of inband_event_descriptor.

syntax value number of bits format inband_event__descriptor() { descriptor_tag 16 Uimsbf descriptor_length 8 Uimsbf scheme_id_uri_length N1 8 Uimsbf for (i=0;i<N1;++i) scheme_id_uri_byte 8 Uimsbf event_value_length N2 8 Uimsbf for (i=0;i<N2;++i) event_value_byte 8 Uimsbf }

Here, the descriptor_tag field is a tag that identifies the inband_event_descriptor, the descriptor_length field indicates the size of the inband_event_descriptor, the scheme_id_uri_length field indicates the byte size of scheme_id_uri, and the scheme_id_uri field defines the meaning and grammar of the value transmitted to the event_data field. The event_value_length field represents the byte size of the event_data field, and the event_value field includes an event value. The range and meaning of event values are determined by scheme_id_uri.

6 is a flowchart illustrating a process of processing event information using an MMT signaling message according to an embodiment of the present invention.

Referring to FIG. 6 , in step 605, the terminal receives a user's input for selecting a service, and in step 610, it monitors reception of an MMT signaling message related to the service and parses the received MMT signaling message. In step 615, the terminal checks whether the AIT message is included in the MMT signaling message, and if there is no AIT message, in step 620, the video/audio stream of the selected service is reproduced. On the other hand, if the AIT message exists, in step 625, the terminal receives data related to the application program service by using the contents of the AI table included in the AIT message. The terminal may determine a reception start time of data related to the application program service, whether to immediately execute the application program service, etc., according to attributes of the application program included in the AI table and user selection.

In step 630, the terminal determines whether an AEI message, which is a signaling message storing event information, is received, obtains information on the event application time from the AE table included in the AEI message, and determines whether the event application time has been reached. When the event application time is reached, in step 635, the application program service is controlled (eg start or end) based on the corresponding event. Until the event application time is reached, the terminal may reproduce the service in step 620.

7 is a flowchart illustrating a process of processing event information using an MPU according to an embodiment of the present invention.

Referring to FIG. 7 , in step 705, the terminal receives a user's input for selecting a service, and in step 710, it monitors reception of an MMT signaling message related to the service and parses the received MMT signaling message. In step 715, the terminal checks whether the AIT message is included in the MMT signaling message, and if there is no AIT message, in step 730, the video/audio stream of the selected service is reproduced. On the other hand, if the AIT message exists, in step 735, the terminal receives data related to the application program service by using the contents of the AI table included in the AIT message. The terminal may determine a reception start time of data related to the application program service, whether to immediately execute the application program service, etc., according to attributes of the application program included in the AI table and user selection.

Meanwhile, in step 715, the terminal checks whether event information is included in the MPU and transmitted based on the MMT signaling message. That is, the terminal analyzes the asset level descriptor included in the MP table in the MMT signaling message to determine whether event information is included in the MPU transmitting the corresponding asset. If the asset level descriptor indicates that event information is included in the MPU, in step 720, the terminal extracts and stores event information from the MPU whenever the terminal receives the MPU of the corresponding asset. In step 740, the terminal periodically checks whether the event application time has been reached while playing the service. For example, information on the event application time may be obtained from an AE table in an AEI message. When the event application time is reached, in step 745, the terminal controls the application program service by applying the corresponding event.

In one embodiment, the signaling table and descriptors can be encapsulated with mmt_atsc3_message(), which can be configured as shown in Table 11 below, and transmitted in the signaling message mode of MMTP.

Syntax No. of Bits Format mmt_atsc3_message() { message_id 16 uimsbf version 8 uimsbf length 32 uimsbf message payload { service_id 16 uimsbf atsc3_message_content_type 16 uimbsf atsc3_message_content_version 8 uimbsf atsc3_message_content_compression 8 uimbsf URI_length 8 uimbsf for (i=0;i< URI_length;i++) { URI_byte 8 uimsbf } atsc3_message_content_length 32 uimsbf for (i=0;i<atsc3_message_content_length;i++) { atsc3_message_content_byte 8 uimsbf } for (i=0;i<length-10-URI_length-atsc3_message_content_length) { reserved 8 uimsbf } } }

The meaning of each field in <Table 11> is as follows.

message_id - 16-bit identifier to identify mmt_atsc3_message()

version - 8-bit identifier to identify the version of mmt_atsc3_message()

length - 32-bit field indicating the length in bytes of mmt_atsc3_message(). The length of the mmt_atsc3_message() may be the number of bytes from the next byte of the length field to the last byte of mmt_atsc3_message().

service_id - 16-bit identifier for identifying the service to which the information transmitted as the payload of mmt_atsc3_message() is applied. Set the same value as the atsc:serviceId attribute of USD to be described later.

atsc3_message_content_type - 16-bit identifier for identifying the type of information transmitted as the payload of mmt_atsc3_message(). For example, the atsc3_message_content_type field may use the values shown in the following <Table 12>.

atsc3_message_content_type Meaning 0x0000 Reserved 0x0001 userServiceDescription 0x0002 MPD 0x0003 Application Information Table 0x0004 Application Event Information 0x0005 Video Stream Properties Descriptor 0x0006 ATSC Staggercast Descriptor() 0x007~0xFFFF Reserved for future use

atsc3_message_content_version - 8-bit identifier to identify the version of information transmitted as message payload of mmt_atsc3_message(). The message payload may be distinguished by a combination of the service_id and the atsc3_message_content_type.

atsc3_message_content_compression - 8-bit field indicating the compression method applied to atsc3_message_content_byte included in the message payload of mmt_atsc3_message().

URI_length - An 8-bit field indicating the length of the URI used to identify the message payload. If no URI is provided, it has a value of 0.

URI_byte - An 8-bit field indicating each byte of the URI used to identify the message payload. It is expressed as a UTF-8 character, and does not include a terminating null character.

atsc3_message_content_byte - 8-bit field representing each byte of information transmitted in the message payload

mmt_atsc3_message() shown in <Table 10> can transmit all types of signaling information including XML and binary formats as a message payload, and the format of each signaling information can be determined using the atsc3_message_content_type.

According to one embodiment, when the above-described inband_event_descriptor is transmitted as the payload of mmt_atsc3_message() in <Table 11>, the inband_event_descriptor may have a format as shown in the following <Table 13>.

syntax value number of bits format inband_event__descriptor() { descriptor_tag 16 Uimsbf descriptor_length 8 Uimsbf number_of_assets N1 8 Uimsbf for (i=0;i<N1;++i) { asset_id_length N2 8 Uimsbf for (j=0;j<N2;++j) { asset_id_byte 8 Uimsbf } scheme_id_uri_length N3 8 Uimsbf for (j=0;j<N3;++j) { scheme_id_uri_byte 8 Uimsbf } event_value_length N4 8 Uimsbf for (j=0;i<N4;++j) { event_value_byte 8 Uimsbf } } }

Here, the descriptor_tag field is a tag for identifying the inband_event_descriptor, the descriptor_length field indicates the size of the inband_event_descriptor, and the number_of_assets field indicates the number of assets described in the inband_event_descriptor. The asset_id_length field represents the byte size of an asset identifier, and the asset_id_byte represents each byte of the asset identifier. The scheme_id_uri_length field represents the byte size of scheme_id_uri, and the scheme_id_uri field defines the meaning and grammar of a value transmitted to the event_data field. The event_value_length field represents the byte size of the event_data field, and the event_value field includes an event value. The range and meaning of the event value is determined by scheme_id_uri.

As an embodiment, event information is transmitted through the MPU of a specific asset, and MMT signaling information may be used to inform that event information is inherent in the MPU of the asset. To this end, mmt_atsc3_message() transmits the inband_event_descriptor, which is a descriptor used at the asset level, in the payload. When the terminal receives inband_event_descriptor through mmt_atsc3_message() and confirms that event information is embedded in the MPU of a specific asset and transmitted, it receives the MPU of the asset and extracts event information from the evti box in the MPU.

Various embodiments of the present invention may be implemented as computer readable code in a computer readable recording medium from a specific point of view. A computer readable recording medium is any data storage device capable of storing data readable by a computer system. Examples of computer readable recording media include read only memory (ROM), random access memory (RAM: 'RAM), and compact disk-read only memory. memory: CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, and carrier waves (data transmission over the Internet, etc.) can include The computer readable recording medium may also be distributed across networked computer systems, so that computer readable code is stored and executed in a distributed manner. In addition, functional programs, code, and code segments for achieving various embodiments of the present invention can be easily interpreted by programmers skilled in the field to which the present invention is applied.

It will also be appreciated that the apparatus and method according to various embodiments of the present invention can be realized in the form of hardware, software, or a combination of hardware and software. Such software may include, for example, volatile or non-volatile storage devices such as ROM, whether removable or rewritable, or memory, such as RAM, memory chips, devices or integrated circuits, or For example, it may be stored in an optically or magnetically recordable and machine (eg, computer) readable storage medium such as a compact disk (CD), DVD, magnetic disk, or magnetic tape. Methods according to various embodiments of the present invention may be implemented by a computer or portable terminal including a control unit and a memory, and such a memory is suitable for storing a program or programs including instructions for implementing the embodiments of the present invention. It will be appreciated that this is an example of a suitable machine-readable storage medium.

Accordingly, the present invention includes a program including code for implementing the device or method described in the claims of this specification and a storage medium readable by a machine (such as a computer) storing such a program. In addition, such a program may be transmitted electronically through any medium, such as a communication signal transmitted through a wired or wireless connection, and the present invention appropriately includes equivalents thereto.

In addition, a device according to various embodiments of the present invention may receive and store a program from a program providing device connected by wire or wirelessly. The program providing device includes a memory for storing a program including instructions for causing the program processing device to perform a preset content protection method, information necessary for the content protection method, and the like, and a wired or wireless communication with the graphic processing device. It may include a communication unit and a control unit that transmits the corresponding program to the transmitting/receiving device at the request of the graphic processing device or automatically.

Embodiments of the present invention disclosed in the present specification and drawings are merely presented as specific examples to easily explain the technical content of the present invention and help understanding of the present invention, and are not intended to limit the scope of the present invention. In addition, the embodiments according to the present invention described above are merely exemplary, and those skilled in the art will understand that various modifications and embodiments of equivalent range are possible therefrom. Therefore, the true technical protection scope of the present invention should be defined by the following claims.

Claims (8)

A method of operating a receiving device in a multimedia system, comprising:
receiving event information related to an event that includes a notification to an application indicating that an action is to occur;
When the event information indicates a first event for dynamic adaptive streaming over hypertext transfer protocol (DASH)-based services, the event information is received in a first event information box included in a media presentation description (MPD),
When the event information indicates a second event for moving picture experts group media transport (MMT)-based services, the event information is displayed in a second event information box included in a media processing unit (MPU) in the MMT payload. received, and
When the event information indicates the second event for the MMT-based services, the event information includes a value for the event, an identifier (ID) of the event, a start time of the event, and duration, and event data of the event,
method.
According to claim 1,
The start time of the event includes the difference between the time at which the MPU is expressed and the time at which the event is applied within the MPU.
method.
According to claim 1,
The event data includes the action,
method.
According to claim 1,
Further comprising, when the event information indicates the second event for the MMT-based services, receiving first information indicating the existence of the event information in the MPU.
method.
As a receiving device in a multimedia system,
transceiver; and
a controller connected to the transceiver;
the controller is configured to receive event information related to an event including a notification to an application indicating that an action is to occur;
When the event information indicates a first event for dynamic adaptive streaming over hypertext transfer protocol (DASH)-based services, the event information is received in a first event information box included in a media presentation description (MPD),
When the event information indicates a second event for moving picture experts group media transport (MMT)-based services, the event information is displayed in a second event information box included in a media processing unit (MPU) in the MMT payload. received, and
When the event information indicates the second event for the MMT-based services, the event information includes a value for the event, an identifier (ID) of the event, a start time of the event, and duration, and event data of the event,
receiving device.
According to claim 5,
The start time of the event includes the difference between the time at which the MPU is expressed and the time at which the event is applied within the MPU.
receiving device.
According to claim 5,
The event data includes the action,
receiving device.
According to claim 5,
Wherein the controller is configured to receive first information indicating the existence of the event information in the MPU when the event information indicates the second event for the MMT-based services,
receiving device.

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