JP2018148574A - Multimedia content receiving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a format for allowing a service provider providing a broadcast communication united type service to transmit breakdown information about a service to be provided by himself/herself.SOLUTION: A receiving device includes a reception part and a control part. The reception part receives a packet including a header and a payload. The control part identifies a control message relating to a package configuration of multimedia content, included in the payload. The control message includes: a control message payload including a table including specific information relating to multimedia content; type information of the control message; information relating to the length of the control message; information relating to the version of the control message; and extended information including configuration information relating to the table included in the control message payload. The table includes an asset list relating to the packet. The specific information includes relating to the package configuration.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for providing a multimedia service, and more particularly, to a method for transmitting breakdown information related to a service provided by a service provider providing a broadcasting / communication integrated service in a heterogeneous network environment.

  The Internet is evolving to a wide band, and not only existing broadcasting using dedicated channels such as terrestrial channels, satellite channels, and cables, but also Internet broadcasting provided by organizing multimedia using the general Internet becomes possible. ing. In addition, a broadcasting / communication-integrated multimedia service that provides various services by combining existing broadcasting and Internet broadcasting more organically has emerged as a realistic service.

  Many broadcast service providers (broadcasting companies) can transmit content not only through dedicated channels but also through the Internet, and on the other hand, broadcasts that transmit content only through the Internet without a dedicated broadcast channel. Service providers have also appeared. Therefore, whether you are a broadcasting company that uses dedicated channels and uses the Internet or a broadcasting company that uses only the Internet, you can view your program content by transmitting your program organization information to many viewers along with the program content. It is necessary to publicize the viewers so that the viewers can watch with good planning. In addition, by providing a “replay” service via the Internet, it is possible to make it possible for viewers to view content that could not be viewed during the main broadcast. In existing broadcasting, this type of information is called an electronic program guide (EPG). In the case of the DVB (Digital Video Broadcasting) system standard, the North American system uses PSIP (Program and System Information Protocol), In the European system, it is called by SI (Service Information). In the MPEG-2 system standard widely used in the existing digital TV system, this is called PSI (Program Specific Information). In the North American system, both PSI and PSIP are transmitted, but the program can be selected by the viewer using only PSIP. In the European system, both PSI and SI can be transmitted and a program can be selected only by PSI, but various guide information about the program is further provided through SI. In the specification of the present application, this type of information is also commonly referred to as service specific information (SSI).

  Unlike existing broadcasts that use dedicated channels, Internet broadcasts are provided globally, so any area that has a receiver that can receive Internet broadcasts exceeds the regional properties of existing broadcasts. For example, it can be accessed anywhere in the world via the Internet. Therefore, in the case of Internet broadcasting, in order to overcome the regional characteristics of existing broadcasting standards roughly divided into North America, Europe, Japan, etc., it must be provided by a single system that is unique in the world, and the complexity of the receiver It is possible to prevent the degree from increasing unnecessarily. From this point of view, SSI further requires a single standardization.

  Future broadcasting / communication integrated broadcasting systems are expected to be reorganized around the Internet. In other words, not only program content via the existing broadcast channel but also guide information about the program content via the Internet is stored and transmitted together in the SSI in a machine-readable format. The receiver acquires such SSI via a broadcast channel or the Internet, uses it for controlling broadcast reception, and shows it in a form that can be read by the viewer if necessary. As a matter of course, Internet broadcasters that do not use a dedicated broadcast channel transmit SSI via the Internet.

  Accordingly, there is a need for an apparatus and method for providing a format for a service provider providing a broadcasting / communication integrated service in a heterogeneous network environment including the Internet to transmit breakdown information regarding the service provided by the service provider.

  The information is presented as background information to help understand the description of the present invention. Whether or not it can be applied as prior art related to the present invention cannot be determined or referred to in any way.

  The features of the present invention solve at least the above-mentioned problems and / or disadvantages and provide at least the effects described below. Accordingly, an object of the present invention is to provide a format for a service provider that provides a broadcasting / communication integrated service in a heterogeneous network environment including the Internet to transmit breakdown information related to the service provided by the service provider. .

  According to one aspect of the invention, a method for receiving a multimedia service is provided. The method includes receiving service breakdown information for at least one multimedia service provided from different networks, selecting one service with reference to the service breakdown information, and selecting the selected service. Receiving process. The service breakdown information includes a first service map table including information on at least one service transmitted through a plurality of logical channels, and at least one transmitted through one logical channel. One of the second service map tables including information about the service may be included. Each of the first service map table and the second service map table may include asset association information.

  According to another aspect of the invention, a method for transmitting multimedia services is provided. The method transmits a service breakdown information for at least one multimedia service provided from a different network, and transmits a service requested by a receiver to the receiver with reference to the service breakdown information. Process. The service breakdown information includes a first service map table including information on at least one service transmitted through a plurality of logical channels, and information on at least one service transmitted through one logical channel. It may include at least one of the second service map tables. Each of the first service map table and the second service map table may include asset association information.

  According to yet another aspect of the invention, an apparatus for receiving multimedia services is provided. The apparatus includes a receiving unit that receives service breakdown information for at least one multimedia service provided from a different network, and a control unit that selects one service with reference to the service breakdown information. The reception unit may receive a service selected by the control unit. The service breakdown information includes a first service map table including information on at least one service transmitted through a plurality of logical channels, and information on at least one service transmitted through one logical channel. It may include at least one of the second service map tables. Each of the first service map table and the second service map table may include asset association information.

  According to yet another aspect of the invention, an apparatus for transmitting multimedia services is provided. The apparatus includes: a transmission unit that transmits service breakdown information for at least one multimedia service provided from a different network; and a control unit that selects a service requested by a receiver with reference to the service breakdown information. Including. The transmission unit may transmit the service selected by the control unit to the receiver. The service breakdown information includes a first service map table including information on at least one service transmitted through a plurality of logical channels, and information on at least one service transmitted through one logical channel. It may include at least one of the second service map tables. Each of the first service map table and the second service map table may include asset association information.

  According to yet another aspect of the invention, a method for receiving a multimedia service is provided. The method includes receiving a control message and decoding the control message. The control message may include at least one table. The at least one table may include a table for one or more MPTs corresponding to a package. The MPT table may include an asset list belonging to a package.

  According to yet another aspect of the invention, an apparatus for receiving multimedia services is provided. The apparatus includes a receiving unit that receives a control message and a decoder that decodes the control message. The control message may include at least one table. The at least one table may include a table for one or more MPTs corresponding to a package. The MPT table may include an asset list belonging to a package.

  According to yet another aspect of the invention, a method for transmitting multimedia services is provided. The method includes generating a control message and transmitting the generated control message. The control message may include at least one table. The at least one table may include a table for one or more MPTs corresponding to a package. The MPT table may include an asset list belonging to a package.

  According to yet another aspect of the invention, an apparatus for transmitting multimedia services is provided. The apparatus includes a control unit that generates a control message and a transmission unit that transmits the generated control message. The control message may include at least one table. The at least one table may include a table for one or more MPTs corresponding to a package. The MPT table may include an asset list belonging to a package.

  Other features, advantages, and salient features of the present invention will become apparent to those of ordinary skill in the art from the following detailed description, taken together with the accompanying drawings.

  According to the present invention, the receiver uses the service breakdown information by applying the format for providing the service breakdown information proposed in the present invention and providing the breakdown information regarding the service provided by the service provider. Thus, the viewer can easily select the broadcast content desired to be viewed.

FIG. 5 is a diagram illustrating a structure of service breakdown information (SSI) and system guide information in an existing broadcast using a dedicated physical channel according to an embodiment of the present invention. It is a figure which shows the structure of SSI in Internet broadcasting. FIG. 3 is a diagram illustrating a logical structure of SSI according to an embodiment of the present invention. It is a figure which shows the usage example of SSI in the broadcast of MPEG-2 TS base. FIG. 3 shows an S1 signaling structure according to an embodiment of the present invention. FIG. 6 is a diagram illustrating a multimedia reception operation in a receiver according to an embodiment of the present invention. FIG. 6 is a diagram illustrating a multimedia reception operation in a receiver according to an embodiment of the present invention. It is a figure which shows the structure of the transmitter by embodiment of this invention. It is a figure which shows the structure of the receiver by embodiment of this invention.

  It should be noted that throughout the attached drawings, the same or similar components, features and structural functions are given similar reference numerals.

  The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the embodiments of the present invention as defined in the appended claims and their equivalents. . Various specific details are included to aid this understanding, but these are just one example. Accordingly, it will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments described herein without departing from the scope or spirit of the invention. In addition, from the viewpoints of clarity and conciseness, detailed descriptions of functions and configurations well known to those skilled in the art are omitted.

  The terms and words used in the following description and claims are not limited to the literature meanings, but are used exclusively by the inventors to enable a clear and consistent understanding of the invention. Accordingly, the description of the embodiments of the present invention is provided for illustration only and is not intended to limit the scope of the present invention, as defined by the appended claims and their equivalents. Is obvious to those with ordinary knowledge in the art.

  Throughout this specification, it should be understood that the singular forms “a”, “an”, and “the” include plural objects unless the context clearly indicates otherwise. . Thus, for example, reference to an “element surface” includes one or more of such surfaces.

  Prior to describing the present invention, terms used in the specification are defined as follows. Media service: A service that conveys information using one or more of various media such as audio, video, image, text, graphics, interactive applications, and the like.

  Foreground media service: video service, audio service, electronic program guide (EPG) service, push video on demand (VoD) service, portal service, etc. Paid or free media products that are directly exposed to viewers so that one viewer can select and enjoy at that time.

  Background broadcast service: assists foreground media services, such as carousel for file download, pre-download over the Internet, but directly to viewers Media transmission service that is not exposed.

  Video service: Video is the main service, and accompanying audio is always provided, and audio in other languages, subtitles, interactive applications, and other additional data may be provided together.

  Audio service: Audio is the primary service, and related video or images, interactive applications, and other additional data may be provided.

  Interactive application: During consumption of video or audio services, called as needed to provide information to the viewer and control the media service in response to the viewer's reaction or to the media provider's server Software that conveys information is collectively referred to as declarative and procedural languages. Called by a media operator in conjunction with a currently consumed video or audio service, or called by a media operator regardless of the currently consumed media service. In addition, an interactive application that is already stored in the receiver cache and recognized by the viewer may be called in response to the viewer's request.

  Regular media: Media that must be provided for media service requirements. For example, audio of an audio service or video and audio of a video service accompanied by audio.

  Adjunct media: Media that does not need to be provided due to media service requirements, but is provided as needed. For example, web documents, widgets, interactive applications, audio clips, video clips, graphics, text, images, auxiliary media components, etc. Auxiliary media is always consumed with regular media and cannot be consumed alone.

  Media component: A component constituting a media. For example, in the case of stereoscopic video, there are a left eye image and a right eye image. As another example, in the case of 5.1 channel audio, each channel audio is a media component.

  Auxiliary media component: A media component that, independently, cannot constitute one media, but constitutes some media along with other media components. For example, in a 2D / 3D mixed-time service, a right-eye image provided only in a stereoscopic video section in a situation where a left-eye image is always provided as a 2D image among left-eye and right-eye images. Auxiliary media component.

  Asset: Encoding data for media components. Here, the encoding refers to compression encoding, encoding conforming to a standard format, and the like.

  Regular asset: Encoding data for the media component of regular media. Here, the encoding refers to compression encoding, encoding conforming to a standard format, and the like.

  Adjunct asset: Encoding data about a media component of an auxiliary media or an auxiliary media component. Here, the encoding refers to compression encoding, encoding conforming to a standard format, and the like.

  Program: An instance of a media service (eg, the entire content of a broadcast channel (logical channel)).

  Program item: content at a certain time interval of a program. For example, when a start advertisement, an intermediate advertisement, and a last advertisement are mixed and transmitted in one movie, the content is a time interval corresponding to the movie including the advertisement. Here, each advertisement is also an individual program item, but is an embedded program item included in another program item. The program is a result of concatenating a plurality of program items (which may include an inclusive program item) that are not inclusive types on the time axis.

  Package: encoded data about a program item. It includes a plurality of assets and control information associated with transmission, decoding, reproduction, etc. of these assets.

  Primary asset: A regular asset that may contain synchronization information about auxiliary assets. For example, the auxiliary information synchronization and control information may be included as attached information of M units of the video stream.

  Attached information: Additional information such as control information and explanation information about an asset. The adhesion information is a logical term, and is actually included in a header of a plurality of layers in the transmission rank, and is called header information in this case.

  Stream asset: An asset in the form of compressed media that can be generated indefinitely in time, such as a video stream and an audio stream.

  Non-stream asset: An asset that does not fall under a stream asset.

  M-unit: The next lower component of an asset. An M unit of a stream-type asset is the smallest unit of data that can be input to a media decoder at a time, and its decoding result can be expressed at a point in time or for a certain time interval by the media. Good. For example, in the case of a video stream, the result of compressing one frame may be one M unit. In the case of an audio stream, the result of compressing audio samples for 24 ms is one M unit. Also good.

  Logical channel: A path that carries a single encoded program. For example, in an existing digital TV system based on MPEG-2 TS (Transport Stream), a data transmission path specified by PMT (Program Map Table), or a source address and a destination address (destination address) on the Internet ), A data transmission path specified by a port number, etc., corresponds to a logical channel.

  Physical channel: A path that carries one or more logical channels. For example, a terrestrial TV channel or cable TV channel having a bandwidth of 6 MHz, a satellite broadcast channel, the Internet, and the like correspond to physical channels.

  IP application data flow: An IP application data flow is specified by a source address and destination address on the Internet, and by a port number in a destination that specifies an application that processes the contents of an IP packet. The

  Asset path identifier (APID): An asset path identifier (for example, information carrying an asset). One IP application data flow includes various asset paths, and each asset path is uniquely identified in one IP application data flow by APID.

  Asset module identifier (AMID): When an asset is divided and transmitted in various asset modules, it is an identifier for identifying these asset modules in one asset path. For example, if there is a table having a large size and this table is divided into many sub-tables, when the entire table is designated as one asset, each sub-table becomes an asset module.

  Hereinafter, a format of service breakdown information according to an embodiment of the present invention will be described with reference to the drawings. First, the service breakdown information should consider the following requirements.

  Integration of guide information: Service breakdown information (SSI) is transmitted via all media such as wired / wireless Internet, terrestrial channels, satellite channels, and cables operated jointly by one broadcaster or multiple broadcasters. Therefore, it is necessary to transmit the breakdown information to the receiver.

  Guide information format: The SSI should have a machine-readable format for the receiver. It is necessary to use a format that can represent the same SSI with as little data as possible.

  Target period of guide information: SSI needs to guide the service breakdown after a certain period of time, past, present, and a certain period (for example, half a month). However, the service breakdown already broadcast in the past may not be directly included in the SSI. In this case, the receiver deletes the past service breakdown already stored for a certain period (for example, for half a month). You may save without.

  Valid period of guide information: The SSI of a specific version is valid only for a certain period, and needs to be automatically updated by the receiver when a predetermined period ends.

  Organization change support: If necessary, when broadcasting content different from the organization content already included in the known SSI, it is necessary to provide means for the transmitter and receiver to modify the already known SSI.

  Guide information transmission means: It is necessary to transmit all or part of the SSI via one or more of media such as wired / wireless Internet, terrestrial channel, satellite channel, and cable, if necessary.

  Selective structure of guide information: Among SSI contents, information essential to the operation of the broadcasting system is compulsorily transmitted, but information that is not necessary needs to have a structure that may be selectively transmitted. . For example, the location information of the program content is essential information for the receiver to read the program stream, while the plot for the program content determines whether or not the viewer views the program. It is not necessary information for the operation of the receiver.

  Minimization of channel acquisition time: The SSI needs to have a structure that can minimize the channel acquisition time. Here, “channel acquisition time” means the time until video and audio are played after power is applied or after a channel is changed.

  Forward compatibility with existing broadcasts: SSI must also guide the service breakdown of existing broadcasts based on MPEG-2 TS.

  Backward compatibility with existing broadcasts: SSI must also be used in existing broadcasts based on MPEG-2 TS. The SSI provided in this way is not used by existing receivers that do not support it, but should not affect its operation. Newer versions of receivers that support SSI can take advantage of SSI.

  Support for multiple small screens within one screen: SSI needs to support multiple small screens within one screen. Here, the positioning function on the time and space of the small screen is included. For example, when a baseball game is broadcast live, it is necessary to include all the small screens that show a pitcher, a batter, a specific infielder, the entire stadium, etc. in the entire screen.

  Support for receivers with various capabilities: SSI supports content guides for receivers with various capabilities such as mobile devices, SDTV (Standard Definition Television), HDTV (High Definition TV), UHDTV (Ultra-High Definition), etc. There is a need to.

  Multi-language broadcasting, caption broadcasting, screen commentary broadcasting, and sign language broadcasting guide support: SSI has auxiliary content that can improve accessibility, such as audio broadcasting in various languages, caption broadcasting, screen commentary broadcasting, and sign language broadcasting. If included in the program, this should be guided.

  Content Usage Restriction Guide: SSI needs to guide several restrictions on content usage. Such restrictions may include content rank (prohibition of viewing below a certain age), video recording possibility, arbitrary accessibility, high-speed playback / reverse playback, pay-per-view, monthly fixed charge, and the like.

  Content data location guide: SSI needs to guide the location of content data. It is necessary to efficiently guide both the case where the entire content is at the same position and the case where the content is different for each content component. In addition, SSI needs to guide the transmission of content by using one or more dedicated broadcast physical channels and the Internet independently or partly or entirely.

  Alternative content data location guide: SSI needs to guide the location of alternative content data. The alternative content data refers to another position where the content selected by the viewer can read the same or similar content as the original content data instead of the intended original content data.

  Auxiliary Data Guide: SSI is not only a guide on primary video and audio, but also accompanying web documents, widgets, interactive applications, audio clips, video clips, graphics, text, images, partial media streams (eg binocular There is a need to provide guidance on auxiliary data such as an additional finite length stream to represent a 3D video for a period of time.

  On the other hand, SSI is provided for each broadcasting company or broadcasting company group. Since terrestrial broadcasters, cable broadcasters, satellite broadcasters, Internet broadcasters, etc. operate independently, unless they share a service breakdown and an integrated transmission, they communicate their service breakdowns independently. There is only. However, if there is such a contract, the service breakdown may be integrated and guided to a broadcaster group that is a group of broadcasters that have participated in the contract. If there is a large amount of information in the service breakdown guide, it takes a long time to download it on the receiver, so the delay time until the viewer browses the service breakdown guide becomes longer, and the modified service breakdown guide is downloaded. However, since the burden increases, a method for overcoming such a point is required.

  In broadcasting systems based on the existing MPEG-2 standard, PSI (Program Specific Information) provided in the MPEG-2 system standard (ISO / IEC 13818-1) is insufficient for the service breakdown guide. Additional services and system guide information are specified and implemented. PSSI (Program and System Information Protocol) of Advanced Television Systems Committee (ATSC) and SI of DVB are PSI. In the case of ATIP PSIP, since it contains information that substitutes for PAT (Program Association Table) and PMT (Program Map Table) in MPEG-2 PSI, there is no need for the receiver to decode the PAT or PMT. It is designed to receive.

  Unlike broadcasting via a dedicated channel that multiplexes and transmits many programs within one physical channel, Internet broadcasting using only the Internet does not multiplex various programs within one IP application data flow. It is normal. Of course, if necessary, various programs may be multiplexed in one IP application data flow. However, in the method proposed by the embodiment of the present invention, one program is included in one IP application data flow. Assuming you only send. In addition, when the program component is divided and transmitted through many different physical channels due to the limitation of the bandwidth of the physical channel, it is not applicable to Internet broadcasting. Under such conditions, SSI for Internet broadcasting can be greatly simplified.

  FIG. 1 is a diagram illustrating a structure of service breakdown information (SSI) in an existing broadcast using a dedicated physical channel according to an embodiment of the present invention.

  The receiver confirms the breakdown of the physical channel from the ATSC PSIP or DVB SI, and when tuning a specific physical channel, the receiver confirms the breakdown of the program in the physical channel from the PAT in the MPEG-2 PSI. When a particular program is selected, the receiver can identify the program component from the PMT in MPEG-2 PSI. In the ATSC system, components of a specific program can be directly identified from PSIP information.

  FIG. 2 is a diagram illustrating an SSI structure necessary for Internet broadcasting according to another embodiment of the present invention.

  The receiver can reproduce the program by confirming the path identifier of the program component from the service breakdown information transmitted via a specific path in the same IP application data flow. Since it is impossible to know in advance when the receiver is turned on, when the Internet broadcast is accessed, etc., the service breakdown information needs to be transmitted periodically. The shorter the cycle, the better. Usually, it is preferable to hold within 500 ms. If the amount of service breakdown information is large, in order to transmit this in a short cycle, it is inefficient because so many packets must be transmitted at the same time interval. Therefore, it is necessary to design the information transmitted in a short cycle to be as small as possible. The additional guide information may be transmitted with a longer period, or else it may be transmitted on request of the receiver.

  FIG. 3 illustrates a logical structure of SSI according to an embodiment of the present invention. For example, FIG. 3 is a logical structure of SSI for broadcasting / communication integrated broadcasting using both a dedicated physical channel and the Internet according to an embodiment of the present invention.

  Referring to FIG. 3, the illustrated structure is basically an integrated form of the structure of FIGS. 1 and 2, and an SMT-M (Service Map Table for Multiple packages) 301 is transmitted via a dedicated broadcast physical channel. The SMT-S (Service Map Table for a Single package) 309 broadcasts a single logical channel via a dedicated broadcast physical channel or only the Internet. Used when broadcasting mainly using the Internet. As an example of broadcasting mainly using the Internet, when a broadcasting company that uses both a dedicated physical channel and the Internet conducts the Internet broadcasting, the data transmitted via the dedicated physical channel may be transmitted via the Internet broadcasting if necessary. The case where it utilizes is mentioned. For example, when a certain content is broadcast on the Internet due to the bandwidth limit of the dedicated channel, auxiliary data additionally used for the content may share the content transmitted through the dedicated channel. In such a case, a receiver that can only access the Internet cannot use auxiliary data. However, a smart TV receiver that has a dedicated channel tuner and an Internet access device is the main content. In the case of auxiliary data received via the Internet, it can be received via a dedicated channel and provided to the viewer comprehensively.

  The SMT-M is a PPT (Package Packing Table) 307-1 to 307 including simple guide contents regarding all programs in a physical channel for transmitting SMT-M information and information of each program item currently being broadcast. -n position reference information, and also includes position reference information and version information about a PGT (Package Guide Table) 305 including guide information on all programs provided by the broadcaster.

  In order to minimize the channel acquisition time, the SMT is periodically transmitted in a very short period (eg, 500 ms), so the amount of information contained is also minimized if possible.

  PGT is the amount of a certain period of all program items serviced through all physical channels operated by one broadcaster and the Internet (for example, past and future half months based on the present) Therefore, the amount of information is significantly larger than that of SMT, and the transmission cycle is also much longer (for example, 1 minute). The PGT may be downloaded by the receiver via the Internet if necessary. The PGT guides program items by a broadcast organization table, but even a broadcast organization table that has been notified in advance can be changed, so it must have a structure that can be updated efficiently. Therefore, the information included in the PGT is configured as a module for each type, and the receiver can download only the updated module. Of course, only the updated modules may be collected and downloaded at a time. This is called the integrated delta module.

  For example, when various integrated delta modules with PGT version differences from 1 to N (where N represents the number corresponding to one or two days) are provided together, the burden of downloading the receiver becomes significant. Can be reduced. If the version of the PGT included in the SMT is different from the version of the PGT currently stored in the receiver, one or more modules in the PGT are added / updated / deleted. Content that is downloaded or deleted with added or updated modules should be deleted, and if the PGT version is the same, the receiver needs to download or decrypt the PGT anew There is no.

  Each module of the PGT contains guide information for one or more program items or corresponding packages, or an additional associated table (eg, a rating table for viewers) necessary for decoding the PGT. )including. The guide information related to the package included in the PGT includes position reference information about the PPT, so that the viewer can select a program using the PGT or can perform scheduled recording. Instead of guiding the outline of the program content with long text information, the URL (Uniform Resource Locator) of the program homepage on the Internet is guided to reduce the amount of information that should be included in the PGT, and the program content depends only on the text Aside from the guide, various program guides using HTML pages and services such as “preview” and “replay” are made possible.

  PPT is information similar to MPEG-2 PMT (Program Map Table), but MPEG-2 PMT is information related to the configuration of a program logical channel that does not distinguish program items, and PPT guides program items separately. The PPT can only guide one package corresponding to one program item. The PPT includes information related to auxiliary data components as well as all program item components constituting the program item. That is, not only information about video and the accompanying regular assets such as audio, but also web documents, widgets, interactive applications, audio clips, video clips, graphics, text, images that are provided together when needed , Information about auxiliary assets, such as auxiliary media components, and location reference information about the resource. Auxiliary asset information and resources are provided in a form in which various packages can share commonly used auxiliary assets in various packages.

  Referring to FIG. 3, SMT-S is similar to PPT in terms of structure and function. In the case of Internet broadcasting, since usually only one program exists in one IP application data flow, it is not necessary to acquire program access information in two steps of SMT and PPT. The same applies to the case where only one program item is broadcast in one broadcast-dedicated physical channel. SMT-S shortens the channel acquisition time by combining the functions of SMT and PPT into one. Within SMT-S, there is a simple guide on the Internet broadcast channel or logical channel itself, a simple guide on the location reference information of the PGT, the version of the PGT, and the program item corresponding to the package currently being broadcast, and the package And various kinds of information related to the assets 311-1 to 311-K constituting the. Accordingly, the SMT-S integrally transmits a logical channel guide, a program item guide, program item component information, and the like.

  A PGT used in Internet broadcasting may include a guide for all Internet broadcasting channels operated by one Internet broadcasting company or group of broadcasting companies, that is, all programs included in various IP application data flows. . A viewer may select a program from one Internet broadcaster or a group of broadcasters by navigation using PGT.

  When real-time Internet broadcasting is performed by MPEG-DASH, SMT-S does not have to guide each program item included in the Internet broadcasting. For example, this corresponds to live streaming in which the length of a program item (actual content is a program in which many program items are continuous) is not specified. However, in this case, the PGT must be guided by program items.

  The position of the PGT provided by the SMT-M is one of a stream in a physical channel that transmits the SMT-M, a stream in another physical channel, a stream in an IP application data flow, and an Internet URL. There may be.

  The location of the asset corresponding to each program item component provided by the PPT is as follows: a stream in a physical channel transmitting the PPT, a stream in another physical channel, a stream in an IP application data flow, an Internet URL (MPEG-DASH URL) Any one of them may be included. An alternative that allows program items transmitted over a broadcast-only physical channel to watch the entire event when, for various reasons, live broadcasts only a portion of the event that the viewer wants to watch Information about the program item may be included. For example, when live broadcasting of an HDTV baseball game is interrupted due to regular scheduling, it is possible to guide an alternative program item by MPEG-DASH, which is a low-resolution video, but allows the viewer to continue to watch it. .

  The position of the PGT provided by SMT-S and the position of the program item component are a stream in a physical channel dedicated to broadcasting carrying SMT-S or a stream in an IP application data flow, and a physical channel dedicated to other broadcasting. Or a stream in a separate IP application data flow, and an Internet URL. When a broadcasting company that uses both a dedicated channel and the Internet implements Internet broadcasting, the position of some program item components of the Internet broadcasting may be a stream in a physical channel dedicated to broadcasting.

  When the location of the PGT is an Internet URL, the receiver accesses the PGT as a whole or a part of the PGT that has been updated or added by accessing the URL whenever necessary or according to a specified period. to download.

  One physical channel includes only one of SMT-M and SMT-S at one time. However, when the number of logical channels in a certain physical channel is changed from a large number to one, a physical channel including only SMT-M can include only SMT-S. In this case, since SMT-M and SMT-S have different table_id values, the receiver can easily distinguish them.

  One of the main functions of SMT-M and SMT-S is to transmit the latest version information of PGT and position reference information of PGT. The receiver may download the latest PGT using the latest version information of the PGT and the position reference information of the PGT included in the SMT-M and SMT-S. If the latest version of the PGT included in the SMT-M and SMT-S is the same version as the PGT that is already stored in the receiver, the receiver can view and listen based on the already stored PGT content. Allows the user to select program items. If the latest version of PGT included in SMT-M and SMT-S is different from the PGT content that the receiver already stores, until the updated PGT is downloaded and stored in the receiver, Based on the PGT, the viewer cannot select the program item.

  In an actual system, it is not necessary to transmit the PGT, but in such a case, the viewer may select a program item mainly based on SMT-M or SMT-S.

  When the receiver is first installed, since there is no downloaded PGT, a broadcast-only physical channel and a logical channel included therein are searched one by one by automatic channel search. At this time, when the broadcasting system provides the PGT, the PGT is downloaded using the PMT position reference information of the SMT-M or SMT-S that is confirmed for the first time, and then the viewer downloads the program item based on the PGT. Allow selection. If this broadcast system does not provide PGT, the receiver will check all logical channels provided by the broadcast system by continuously performing automatic channel search, after which the viewer will select the channels in the order of logical channels. To be able to navigate.

  Subsequently, when the receiver used is turned off and turned on again, the program item of the logical channel that was previously viewed is first played back. In this process, the SMT-M or SMT-S Check the PGT information and update the PGT. The viewer performs channel navigation in the order of logical channels or decodes the PGT information and selects a desired program item from among the program items currently being broadcast.

  In the case of Internet broadcasting, a broadcast server address that is already stored at the time of manufacture of the receiver, a broadcast server address that is input to the receiver later by the viewer, and a broadcast server address acquired by PGT are stored in advance in the receiver. It may be stored and selected by the viewer's channel navigation or may be selected based on the PGT program item guide.

  When the viewer selects a program item based on the PGT program item guide, the receiver actually accesses the logical channel on which the program item is transmitted and is currently broadcasting over that logical channel. Show the program item. Very rarely, from when a viewer selects a program item with reference to the PGT program item guide until just before decoding the actual SMT-M or SMT-S of that program item. The content of the PGT may be updated. In such a case, the receiver updates the PGT using the PGT information included in the SMT-M or SMT-S, and the program item currently being viewed by the viewer due to the emergency organization is changed to the previous version. If the program item is different from the program item guided by the PGT, an appropriate guide is displayed on the screen so that the viewer can recognize the program item currently being viewed.

  Referring to FIG. 3, an asset referred to by SMT-S or PPT may actually be a media asset or other PPT. However, a double recursive reference in which a PPT referenced by SMT-S or PPT re-references another PPT is not allowed. When SMT-S or PPT also refers to another PPT as an asset, MMT composition information must be transmitted for screen layout. If the screen layout is not switched according to time in one program item and is fixed, if this amount is not large, MMT (MPEG Media Transport) composition information is transmitted by being included in a descriptor in PPT. May be. When the screen layout is switched according to time in one program item, the MMT composition information is transmitted as a timed asset. On the other hand, the screen layout is not switched according to time in one program item, but if the amount of composition information is large, the MMT composition information may be transmitted as an untimed asset.

  The SSI proposed in the present invention can be used interchangeably in a broadcasting system based on the existing MPEG-2 system standard.

  FIG. 4 is a diagram illustrating an example of using SSI in MPEG-2 TS-based broadcasting according to an embodiment of the present invention. For example, FIG. 4 shows an example of an MPEG-2 TS that can be interpreted by both an existing broadcast receiver and a receiver that supports MMT.

  Referring to FIG. 4, in this example, there are two programs in one TS. The existing broadcast receiver decodes MPEG-2PAT, MPEG-2PMT1, and MPEG-2PMT2 and receives the program. A receiver that supports MMT receives the program by decoding MMT SMT-M, MMT PPT1, and MMT PPT2. Of course, the PID of the TS packet carrying the MMT SMT-M needs to be assigned in advance as a fixed value, and the SMT-M and the PPT are transmitted after being encapsulated in the structure of the MPEG-2 section. There is a need.

  Next, the standard of the SSI information format proposed by the embodiment of the present invention will be described. The SMT-M (Service Map Table for Multiple packages), when broadcasting a plurality of logical channels via a dedicated broadcast physical channel, is a PPT corresponding to all program items currently broadcast on the dedicated physical channel of the broadcast. Used to communicate position and program guide version and position. The SMT-M is preferably transmitted in a period of 500 ms, and when the receiver accesses the dedicated physical channel of the broadcast, the package corresponding to the program item is quickly found.

  The SMT-M APID is always fixed to a specific value (for example, 0x0000). When SMT-M is transmitted via MPEG-2 TS, it is necessary to specify the PID of the TS packet carrying SMT-M as a fixed value.

  Table 1 shows the syntax of SMT-M. The definition of content listed in the “Format” column of Table 1 follows the MPEG-2 system standard. A loop count not displayed in the “value” column of Table 1 is a value derived from a value indicating the length. Such principles apply to other tables presented by embodiments of the present invention.

In Table 1, the meaning (semantics) of each syntax element is as follows.
table_id: An identifier indicating the type of table. A unique value corresponding to SMT-M is assigned.
version_id: An identifier indicating the configuration of this table. This value changes when the table structure is modified by the standard revision. Based on this value, the receiver determines whether this table is configured so that it can understand the contents of the table. This value is only increased when the table contents are revised incompatible with the existing one.

table_length: Number of bytes from this field to the last byte of service_map_table_type_I (). A value of 0 is not used.
service_id: A unique identifier for a broadcast service using a dedicated broadcast channel. It is necessary to assign a unique identifier to each broadcaster's dedicated broadcast channel via a registration organization.

  SMT_update_version: Since SMT-M is periodically transmitted, if the SMT-M content is different from the SMT-M content having the same service_id transmitted immediately before, this value is increased by one. After the maximum value 255, it is reset to zero. When this value changes, the receiver reads the content of SMT-M again and decrypts it.

  SMT_prefix_count: Number of subsequent SMT_prefix. SMT_prefix is concatenated before the text string included in SMT-M to form a URL. When referring to SMT_prefix, SMT_prefix is referenced using the appearance order of SMT_prefix as an index. The value “OxFF” in this field is not used. Therefore, a maximum of 255 SMT_prefixes may be included.

SMT_prefix_length: Length of SMT_prefix text string.
SMT_prefix_byte: SMT_prefix text string byte. Does not include the final null byte of the text string.

  SMT_M_descriptors_length: represents the length of the next SMT_M_descripor syntax loop in this field as the number of bytes from the next byte to the last byte of the SMT_M_descripor syntax loop. SMT_M_descripor () may include various descriptors including PGT_reference_descriptor () described below.

number_of_packages: The number of packages currently being transmitted over this broadcast channel.
package_path_number: Package path number that distinguishes logical channels within a certain broadcast channel. A value of “0” is not used. The package_path_number is uniquely assigned within a physical channel by one broadcasting company or broadcasting company group.

  package_id: The identifier of the package currently being transmitted through this virtual channel. The package_id is a value assigned by the broadcaster for each package, and has a unique value of a package provided by one broadcaster or a group of broadcasters during a certain period. This value may be reused after a certain period of time.

  simple_location_type: Specifies the type of location reference information for PPT corresponding to the currently transmitted package. The PPT referenced by the SMT-M is transmitted in the same IP application data flow as the IP application data flow carrying the SMT-M or in the same MPEG-2 TS as the MPEG-2 TS carrying the SMT-M. Is done. When the value of this field is “0”, the asset route carrying PPT is designated as APID, and when the value of this field is “1”, MPEG-2 TS carrying PPT is defined in MPEG-2. Designated PID.

PPT_APID: The identifier of the asset route that carries the PPT in the IP application data flow.
PPT_PID: PID of a TS packet carrying PPT in MPEG-2 TS.
CRC_32: The same field as CRC_32 defined by the section syntax of the MPEG-2 system standard.

  SMT-S (Service Map Table for a Single package) is a program item when broadcasting a single logical channel through a dedicated broadcast physical channel, using only the Internet, or mainly using this. It is used to convey simple guide information about the corresponding package, location reference information for more detailed program guide information, the composition of program items, and location reference information for its components. The SMT-S needs to be transmitted in a cycle within 500 ms, and the APID of the SMT-S is always fixed as a specific value (for example, 0x0000). Therefore, SMT-M and SMT-S are transmitted via a route having the same APID, but are identified by table_id.

The syntax of SMT-S is as shown in Table 2.

In Table 2, the meaning of each syntax element is as follows.
table_id: An identifier indicating the type of table. A unique value corresponding to SMT-S is assigned.

  version_id: An identifier indicating the configuration of this table. This value changes when the table structure is modified by the standard revision. Based on this value, the receiver determines whether this table is configured so that it can understand the contents of the table. This value increases only when the contents of the table are revised incompatible with the existing one.

table_length: Number of bytes from this field to the last byte of service_map_table_type_II (). A value of 0 is not used.
service_id: A unique identifier for the Internet broadcast service. It is necessary to assign a unique identifier to each broadcaster's IP application data flow through the registration organization.

  SMT_update_version: Since SMT-S is transmitted periodically, this value increases by one if the content of SMT-S is different from the content of SMT-S having the same service_id transmitted immediately before. After the maximum value 255, it is reset to zero. When this value changes, the receiver reads the SMT-S content again and decrypts it.

CRC_32 is the same field as CRC_32 defined by the section syntax of the MPEG-2 system standard.
PPT_body (): A syntax element group corresponding to the body of PPT in MMT, and its syntax is as shown in Table 3.

In Table 3, the meaning of each syntax element is as follows.
short_channel_name_length: the number of bytes of the logical channel name represented by a text string using UTF-8 encoding.

short_channel_name_byte: Byte data constituting the logical channel name.
package_id: The identifier of the package currently being transmitted through this virtual channel. The package_id is a value assigned by the broadcaster for each package, and has a unique value of a package provided by one broadcaster or a group of broadcasters during a certain period. This value may be reused after a certain period of time.

  prefix_count: Number of subsequent prefixes. The prefix is concatenated to the end of the text string to form a URL. When attempting to refer to the prefix, the receiver refers to the prefix by using the appearance order of the prefix as an index. The value “OxFF” in this field is not used. Therefore, a maximum of 255 prefixes can be included.

prefix_length: Length of prefix text string.
prefix_byte: Byte in the prefix text string. The last null byte of the text string is not included.

  descriptors_length: The length of the next descriptor syntax loop of this field is expressed as the number of bytes from this next byte to the last byte of the descriptor syntax loop. Various descriptors may be included in descriptor (), but when the PPT_body () syntax element group in Table 3 is included in SMT-S, PGT_reference_descriptor () is included in this descriptor (). May be.

  parental_guidance_flag: If the value of this flag is “1”, the receiver will not play the content restored from the package until it has decoded the PGT to determine the exact viewer rank applied to this package . If the value of this flag is “0”, the receiver plays back the content restored from the package even before confirming the viewer rank.

recording_flag: When the value of this flag is “1”, the receiver can store this package in a storage medium in the receiver.
random_access_flag: When the value of this flag is “1”, the viewer can arbitrarily access this package.

fast_forward_play_flag: When the value of this flag is “1”, the viewer can perform high-speed playback with this package.
fast_reverse_play_flag: If the value of this flag is “1”, the viewer can perform high-speed reverse playback with this package.

timescale_flag: If the value of this field is “1”, the timescale field is included below.
protection_scheme_id_flag: If the value of this field is “1”, a protection_scheme_id field is included below.

  timescale: represents the time unit applied to various timestamps of the asset as the number of time units per second. The default value is 90,000. There are two timescale fields in PPT_body (), but the preceding one is the value that applies to all assets belonging to the package, and the latter in the asset syntax loop is the value that applies to each asset. It is. If there is a value that applies to each asset, this value overrides the value that applies to the entire preceding asset.

  protection_scheme_id: A value that specifies the asset encryption scheme. There are two protection_scheme_id fields in PPT_body (), but the preceding one is a value that applies to all assets belonging to the package, and the latter in the asset syntax loop applies to each asset. Value. If there is a value that applies to each asset, this value overrides the value that applies to the entire preceding asset.

  clock_reference_id: The clock identifier used by the asset's encoder. There are two clock_referece_id fields in PPT_body (), but the preceding one is the value that applies to all assets belonging to the package, and the latter in the asset syntax loop is the value that applies to each asset. It is. If there is a value that applies to each asset, this value overrides the value that applies to the entire preceding asset.

  number_of_asset_groups: Number of asset groups. Assets belonging to the same asset group are mutually exclusive. That is, the receiver reproduces only one asset among assets belonging to the same group. For example, for multi-language support, A language audio and B language audio may belong to the same asset group.

  level_of_mandatory_playing: A value indicating whether or not one asset in the asset group needs to be replayed. If the value of this field is “0”, the receiver must replay one asset of this asset group. If the value of this field is not “0”, the receiver may not play the asset belonging to the asset group depending on its capability. However, the greater the value of this field, the lower the importance. The receiver may omit an asset group with a small value in this field and does not need to play an asset group with a field value greater than that.

number_of_assets_in_group: Number of assets that belong to this asset group.
asset_type: The type of asset. This field is similar to stream_type in MPEG-2 PMT, but is an extended field. If asset_type is PPT, this asset is referred to as a PPT asset. However, double recursive references that refer to other PPT assets within a PPT asset included in SMT-S or PPT are not allowed.

asset_id: Asset identifier. asset_id is used to refer to the asset in MMT_package_composition_descriptor ().
default_selection_flag: If the value of this flag is “1”, this indicates that the asset is an asset that is preferentially recommended within the asset group to which it belongs. It is necessary to set the value of this flag to “1” only for one asset among assets belonging to the same asset group. When the value of this flag is “0” for all assets belonging to the same asset group, the receiver regards the asset that appears first as the asset that has been preferentially recommended.

clock_reference_flag: When the value of this flag is “1”, it indicates that the clock_reference_id field is included in the following syntax.
asset_timescale_flag: If the value of this flag is “1”, it indicates that the timescale field is included in the following syntax.
asset_protected_flag: If the value of this flag is “1”, this indicates that the asset is encrypted.

scheme_id_flag: If the value of this flag is “1”, it indicates that the protection_scheme_id field is included in the following syntax.
MMT_general_location_info (): General location reference information for MMT, which specifies the location of an asset. The contents are shown in Table 5.
asset_descriptors_length: The number of bytes from this field to the last byte of the descriptor syntax loop.
asset_descriptor (): Asset descriptor.

  PPT_asset () is a syntax element group used to include other packages in a certain package. The syntax is as shown in Table 4, and the meaning of each syntax element is as defined in Table 3 above.

  MMT_general_location_info () is a syntax element group that provides asset location reference information in MMT. The syntax is shown in Table 5.

In Table 5, the meaning of each syntax element is as follows.
location_type: Specifies the format of the location reference information as shown in Table 6.

AMID: Module identifier in the asset path.
APID: Asset path identifier in the IP application data flow.
Ipv4_src_addr: IP version 4 source address of the IP application data flow.
ipv4_dst_addr: IP version 4 destination address of the IP application data flow.
dst_port: Destination port number of the IP application data flow.
ipv6_src_addr: IP version 6 source address of the IP application data flow.
ipv6_dst_addr: IP version 6 destination address of the IP application data flow.
network_id: a broadcasting network identifier for transmitting MPEG-2 TS.
MPEG_2_transport_stream_id: An identifier of MPEG-2 TS.
MPEG_2_PID: PID of MPEG-2 TS packet.

prefix_index: An index that specifies one of the prefixes stored in the receiver before decoding this field. If the value of this field is OxFF, it indicates that there is no prefix.
URL_length: URL length. The last null byte (0x00) of the text string is not included.
URL_byte: URL byte. The last null byte of the text string is not included.
byte_offset: Byte offset from the beginning of the file.
length: Length in bytes.

  The PPT (Package Packing Table) is a program item and a simple guide information about a package corresponding to the program item, a location reference information about a more detailed program guide information, and a program item in broadcasting using a physical channel dedicated to broadcasting. And the position reference information of the component are transmitted. The PPT is preferably transmitted in a cycle within 500 ms.

  The syntax of PPT is almost the same as that of SMT-S except that the service_id syntax element is replaced with the package_path_number syntax element in the syntax of SMT-S. The syntax of PPT is as shown in Table 7. Most syntax elements are similar to SMT-S in terms of meaning, so only syntax elements having different meanings are defined.

In Table 7, the meaning of each syntax element is as follows.
table_id: An identifier indicating the type of table. A unique value corresponding to the PPT is assigned.
package_path_number: The number of the package path that distinguishes logical channels within a certain broadcast channel. A value of “0” is not used. The package_path_number is uniquely assigned within a physical channel by one broadcasting company or broadcasting company group.

  A PGT (Package Guide Table) can guide programs organized in all broadcasts operated by one broadcaster or a group of broadcasters as program guide information. The PGT is preferably transmitted in a cycle of 1 minute or less.

  The PGT basically provides guide information in units of program items. The receiver classifies and provides this by physical channel or logical channel. Of course, the PGT includes information that enables such sorting. According to a predetermined rule on the transmission side, guide information of program items may be arranged and transmitted.

  The program item is identified by a package identifier, package_id, which is the encoding form. The package_id can uniquely identify a program item provided by one broadcaster or one broadcaster group. One broadcaster or one broadcaster group is uniquely identified by PGT_provider_id. PGT_provider_id must be assigned according to the request of each broadcaster or broadcaster group by designating a registration organization. In the case of package_id, each broadcaster or broadcaster group uniquely assigns it to its own program item. Since package_id is a 16-bit value and can identify a finite number of program items, it needs to be reused after a certain period of time. At the time of reuse, package_id_recycle_number (8 bits as one of the syntax elements included in PGT_package_info ()) is incremented by one. A set of three pieces of information composed of PGT_provider_id, package_id_recycle_number, and package_id is a globally unique identifier for a program item or a corresponding package until the package_id_recycle_number is exhausted. For example, assuming that it takes roughly one year to exhaust package_id, the package_id_recycle_number is 8 bits, so the uniqueness is guaranteed for about 256 years.

  The PGT is composed of an identifier of the broadcasting company or broadcasting company group providing the PGT, an updated version, a homepage URL of the broadcasting company or broadcasting company group providing the PGT, update module information, logical channel information, package information, attached table information, and the like. Is done. The update module information is information including only a different part from the past PGT version that can be distinguished from the current PGT version as a form of delta information. If update module information corresponding to about one or two days is included in the PGT, the PGT update process in the receiver can be performed very efficiently.

The syntax of PGT is as shown in Table 8.

In Table 8, the meaning of each syntax element is as follows.
table_id: An identifier indicating the type of table. A unique value corresponding to PGT is assigned.
version_id: An identifier indicating the configuration of this table. This value changes when the table structure is modified by the standard revision. Based on this value, the receiver determines whether this table is configured so that it can understand the contents of the table. This value is only increased when the table contents are revised incompatible with the existing one.

  PGT_provider_id: A unique identifier of the organization that provides the PGT. One institution can provide one PGT, and PGT_provider_id is assigned by a suitable registration institution.

  PGT_update_version: Version number indicating whether or not the PGT content has been changed. When the PGT content is updated, this value is incremented by one. After the maximum value 255, it is reset to zero. When the version number of the PGT stored in the receiver is different from this value, the receiver reads the PGT again and decrypts the content.

table_length: Number of bytes from this field to the last byte of package_guide_table (). A value of 0 is not used.
PGT_prefix_count: The number of prefixes used in PGT. The prefix is connected to the end of the text string included in the PGT. When referring to a prefix, the prefix is referenced by using the appearance order of the prefix as an index. The value of OxFF is not used as an index value. Therefore, a maximum of 255 prefixes may be included.

PGT_prefix_length: Length of PGT_prefix text string.
PGT_prefix_byte: The text string byte of PGT_prefix. The last null byte of the text string is not included.
PGT_provider_homepage_URL_prefix_index: Index for the homepage URL prefix of the organization providing the PGT. A value that designates one of the preceding prefixes and the value of this field is OxFF indicates that there is no prefix text string.

PGT_provider_homepage_URL_length: The length of postfix bytes in the homepage URL of the organization providing the PGT.
PGT_provider_homepage_URL_byte: ASCII text value of postfix in the homepage URL of the organization that provides PGT.
PGT_descriptors_length: Length of the next descriptor syntax loop byte.
PGT_descriptor (): Descriptor associated with PGT.

  redirect_flag_for_delta_update_info: If the value of this flag is “0”, the PGT update information is directly included in the PGT, and if the value of this flag is “1”, it is located elsewhere.

  redirect_flag_for_logical_channel_info: When the value of this flag is “0”, the logical channel information is directly included in the PGT, and when the value of this flag is “1”, it is located elsewhere.

  redirect_flag_for_package_info: If the value of this flag is “0”, the package information is directly included in the PGT. If the value of this flag is “1”, the package information is located elsewhere.

  redirect_flag_for_associated_table_info: If the value of this flag is “0”, the attached table information is directly included in the PGT, and if the value of this flag is “1”, it is located elsewhere.

PGT_delta_update_info_module_count: Number of PGT_delta_update_info_module.
PGT_update_delta: A value corresponding to a difference between a past PGT version serving as a reference and a current PGT version when creating PGT_delta_update_module. The next MMT_general_location_info () specifies the location of PGT_delta_update_module ().
PGT_delta_update_info_module (): A data module consisting only of different information between a previous version of PGT as much as PGT_update_delta and the current version of PGT.

  PGT_logical_channel_info_update_version: The version of PGT_logical_channel_info () defined in Table 10. Immediately following MMT_general_location_info () specifies the location of PGT_logical_channel_info ().

PGT_logical_channel_info (): Logical channel information defined in Table 10.
PGT_package_info_module_count: Number of PGT_package_info_module ().
PGT_package_info_module_id: PGT_package_info_module () identifier.
PGT_package_info_module_update_version: PGT_package_info_module () version. Immediately following MMT_general_location_info () specifies the location of PGT_package_info_module ().

PGT_package_count: Number of packages.
PGT_package_info (): Package information defined in Table 11. One package information includes only one package information.

PGT_associated_table_info_module_count: Number of PGT_associated_table_info_module ().
PGT_associated_table_info_module_id: identifier of PGT_associated_table_info_module ().

  PGT_associated_table_info_module_update_version: PGT_associated_table_info_module () version. Immediately following MMT_general_location_info () specifies the location of PGT_associated_table_info_module ().

PGT_associated_table_count: Number of tables associated with PGT. Tables having the same table_id are regarded as one table.
PGT_associated_sub_table_count: The number of sub-tables in the table attached to PGT.

PGT_associated_sub_table (): A subtable in a table attached to PGT.
PGT_delta_update_info_module () is a syntax element group that includes only updated information in the contents of the PGT. The PGT_delta_update_info_module () may selectively include updated logical channel information, each updated package information, and each updated associated sub-table.

  When the PGT_update_version is different from the PGT version stored in the PGT_update_version, the PGT_update_delta is a difference obtained by subtracting the PGT version stored in the PGT_update_version after decrypting the PGT_descriptor () loop in the PGT contents. If there is PGT_update_delta, the PGT update can be completed by decoding the PGT_delta_update_info_module ().

The syntax of PGT_delta_update_info_module () is as shown in Table 9.

In Table 9, the meaning of each syntax element is as follows.
PGT_update_delta: A value corresponding to a difference between a past PGT version serving as a reference and a current PGT version when creating a PGT_delta_update_module.
PGT_delta_update_info_module_length: The number of bytes from the next of this field to the last byte of PGT_delta_update_info_module ().

update_logical_channel_info_flag: When the value of this flag is “1”, it indicates that update information about logical channel information is included.
update_package_info_flag: If the value of this flag is “1”, it indicates that update information about the package information is included.
update_associated_table_flag: If the value of this flag is “1”, it indicates that update information about the table information attached to the PGT is included.

PGT_logical_channel_info (): Logical channel information defined in Table 10.
PGT_package_update_count: The number of package update information included in the next syntax loop.
PGT_package_info (): Package information defined in Table 11.
PGT_associated_table_update_count: The number of sub-tables in the updated PGT attached table included in the next syntax loop.
PGT_associated_sub_table (): A subtable in the table attached to PGT.

  PGT_logical_channel_info () is a syntax element group corresponding to metadata about all logical channels provided by the PGT provider in the PGT content.

  The syntax of PGT_logical_channel_info () is as shown in Table 10. Here, the syntax loop index PGT_logical_channel_index is an index used in the package information.

In Table 10, the meaning of each syntax element is as follows.
PGT_logical_channel_info_update_version: Version of PGT_logical_channel_info (). Each time the content of the logical channel information changes, it is incremented by one, and at 255 it is reset to zero.

PGT_logical_channel_info_length: The number of bytes from the next of this field to the last byte of PGT_logical_channel_info ().
PGT_logical_channel_count: Number of logical channels guided by PGT.
short_channel_name_length: the number of bytes of the logical channel name represented by a text string using UTF-8 encoding.

short_channel_name_byte: Byte data constituting the logical channel name.
physical_channel_type: The type of the physical channel that carries the logical channel. A value of “0” in this field indicates the Internet, a value of “1” indicates a terrestrial wave, a value of “2” indicates a satellite, and a value of “3” indicates a cable.

major_channel_number: Major channel number.
minor_channel_number: Secondary channel number.
service_id: identifier of the MMT service.

  package_path_number: Package path number that distinguishes logical channels within a certain broadcast channel. A value of “0” is not used. The package_path_number is uniquely assigned within a physical channel by one broadcasting company or broadcasting company group.

  test_channel_flag: This logical channel indicates that it is a test logical channel. If the value of this flag is “1”, the general receiver does not provide this logical channel information in the program guide.

nvod_channel_flag: indicates that this logical channel is for NVOD (Near Video On Demand).
relay_broadcast_flag: Indicates that this logical channel is a retransmission channel of another logical channel. For example, when terrestrial broadcasting is retransmitted with a cable, the value of this flag is set to “1” for the logical channel.

  channel_protection_type: Indicates the encryption form applied to this logical channel. If the value of this field is “0”, it means that it is not encrypted, if it is “1”, it means that all packages in this logical channel are encrypted, and if it is “2”, “3” indicates that only some of the assets belonging to the packages in this logical channel or some / all of the assets are encrypted, and “3” indicates that only some of the packages are encrypted. Show. When the value of this field is “2”, for example, it indicates that only the video is encrypted or only the first 10 minutes of the package is encrypted. A value of “3” in this field indicates, for example, that only some packages carried by this logical channel are encrypted.

original_physical_channel_type: Original physical channel type.
original_major_channel_number: Original main channel number.
original_minor_channel_number: Original secondary channel number.
MMT_general_location_info (): Designates the location of PPT or SMT-S corresponding to this logical channel.
descriptors_length: Length of the next descriptor syntax loop.
descriptor (): Descriptor associated with logical channel information.

  PGT_package_info () is a syntax element group corresponding to metadata about one package among the contents of the PGT. The syntax of PGT_package_info () is as shown in Table 11.

In Table 11, the meaning of each syntax element is as follows.
package_id: The identifier of the package currently being transmitted over this logical channel. The package_id is a value assigned by the broadcaster for each package, and has a unique value of the package for a certain period. This value may be reused after a certain period of time.
PGT_package_info_update_version: The version of PGT_package_info (). This value is incremented by one each time the content of the package information changes, and is reset to 0 in 255.

PGT_package_info_length: The number of bytes from the end of this field to the last byte of PGT_package_info ().
package_id_recycle_number: The value of this field is incremented by one each time a 16-bit package_id number assignment is completed. A unique package identifier along with package_id.

start_time: Indicates the start time of the program item corresponding to this package in UTC.
duration: Indicates the duration of the program item corresponding to this package in seconds. When the value of this field is “0”, it means “the duration is not known”.

title_text_language_count: The number of languages indicating the title of the program item corresponding to this package.
title_text_language: A 3-byte language identifier according to the ISO 639 standard indicating the title language of the program item corresponding to this package.
title_text_length: notifies the length of the UTF-8 text string indicating the title of the program item corresponding to this package in bytes.
title_text_byte: The text string byte of the title of the program item corresponding to this package.

  package_homepage_URL_prefix_index: Prefix index for the home page URL of the program item corresponding to this package. This field has a value that specifies one of the prefixes defined by PGT_header (). If the value of this field is OxFF, it indicates that there is no prefix.

package_homepage_URL_length: The length of the next postfix in the homepage URL of the program item corresponding to this package.
package_homepage_URL_byte: the ASCII text value of postfix in the homepage URL of the program item corresponding to this package.

  format_type: Specifies the format of PGT_package_info (). If the value of this field is “0”, PGT_package_info () contains minimal information about the current or future package, and if it is “1”, PGT_package_info () will contain information about program items that have already been broadcast. If only “replay” information is included and “2” is set, PGT_package_info () includes all information on a program to be broadcast at present or later. “Replay” is a service in which program items that have already been broadcast can be downloaded or streamed from an Internet server for free or viewed.

PGT_logical_channel_index: Index that specifies information about the logical channel that carries this package. The value of this index is the index of the logical channel provided by PGT_logical_channel_info () in Table 10.
post_event_replay_URL_flag: indicates that there is a “replay” URL for this package.

  post_event_replay_URL_prefix_index: The index for the “replay” URL prefix of this package. This field has a value that specifies one of the prefixes defined by PGT_header (). A value of “0” in this field indicates that there is no prefix. If the value of this field is not “0” but “N”, the Nth prefix is designated.

post_event_replay_URL_length: The length of the next postfix in the “replay” URL of this package.
post_event_replay_URL_byte: ASCII text value of postfix in the “replay” URL of this package.

  package_protection_type: Indicates the encryption type applied to this package. If this value is “0”, it is not encrypted. If it is “1”, all assets in this package are encrypted. If it is “2”, Indicates that only a part of the asset or only a part of the asset is encrypted, and a value of “3” is not used. When the value of this field is “2”, for example, it indicates that only the video asset is encrypted, or that only the first 10 minutes of the video asset and the audio asset are encrypted.

  pay_type: This field has no meaning if the package_protection_type is “0”, so it is ignored by the receiver, and has a meaning if it is “1” or “2”. A value of “0” in this field indicates “pay subscription required”, and a value of “1” indicates “pay-per-view”. Related payment guide information needs to be provided using descriptors in the PGT_descriptor () syntax loop of Table 8 or the PGT_package_info_descriptor () syntax loop of Table 11. If payment guide information exists in both the PGT_descriptor () syntax loop and the PGT_package_info_descriptor () syntax loop, the one in the PGT_package_info_descriptor () syntax loop takes precedence.

  content_id_flag: When the value of this flag is “1”, it indicates that a unique content identifier is included in the world for the program item corresponding to this package.

  genre_flag: If the value of this flag is “1”, it indicates that the genre information of the program item corresponding to this package is included. When the value of this flag is “1”, it is necessary to transmit the genre table (genre table) to the receiver as PGT_associated_table.

  parental_guidance_flag: If the value of this flag is “1”, it indicates that viewer rank information is included. When the value of this flag is “1”, it is necessary to transmit the viewer rank table to the receiver as PGT_associated_table.

live_flag: If the value of this flag is “1”, this indicates that this package is a live broadcast rather than a recorded or recorded content.
serial_flag: When the value of this flag is “1”, it indicates that the program item corresponding to this package is one time in a series like a serial drama.
rebroadcast_flag: When the value of this flag is “1”, it indicates that the program item corresponding to this package is “rebroadcast” of the program item already broadcast.

rebroadcast_exist_flag: A value of “1” indicates that there is a “rebroadcast” plan for the program item corresponding to this package.
recording_flag: If the value of this flag is “1”, this indicates that this package can be recorded.
multilingual_flag: When the value of this flag is “1”, it indicates that multilingual audio is supported.

commentary_channel_flag: If the value of this flag is “1”, this indicates that there is “screen commentary broadcasting” for this package.
sign_language_flag: If the value of this flag is “1”, it indicates that there is “sign language broadcasting” for this package.
subtitles_flag: If the value of this flag is “1”, it indicates that there is “caption broadcasting” for this package. Subtitles are based on UTF-8 encoding.

  multivew_flag: If the value of this flag is “1”, this indicates that the entire package is “multi-view broadcasting” or that “multi-view broadcasting” is partially included in this package. “Multi-view broadcasting” includes binocular stereoscopic broadcasting, multi-view 3D broadcasting, multi-view broadcasting, and the like.

  picture_size_grade_count: Number of ranks of screen size. When the value of this field is “2” or more, it indicates that a plurality of screen size ranks are provided by simultaneous broadcasting or spatial scalability encoding.

  picture_size_grade: The rank of the screen size. For example, if the value of this field is “0”, the horizontal resolution is used as a reference, 240 pixel class, “1” is 480 pixel class, “2” is 720 pixel class, “3”. If it is, 1,280 pixel class, “4” indicates 1,920 pixel class, “5” indicates 3,840 pixel class, and “6” indicates 7,680 pixel class. If the picture_size_grade is two or more, it indicates that the video is provided by spatial scalability encoding.

audio_language: 3-byte language identifier according to the ISO 639 standard indicating the language of the audio.
audio_grade: Indicates the type of audio. For example, a value of “0” in this field indicates that the audio is mono, “1” indicates that the audio is stereo, and a value of “2” indicates that the audio is 5. This indicates that the audio is 1-channel audio, and “3” indicates that the audio is 22.2-channel audio.

additional_audio_count: The number of additional other language audio.
additional_audio_language: 3-byte ISO 639 language identifier for additional audio in a language different from the main audio.
additional_audio_grade: Indicates an additional language audio type. For example, a value of “0” in this field indicates that the audio is mono, “1” indicates that the audio is stereo, and a value of “2” indicates that the audio is 5. This indicates that the audio is 1-channel audio, and “3” indicates that the audio is 22.2-channel audio.

content_originator_id: A world-unique identifier indicating the author of the main content of the program item corresponding to this package. This identifier must be used after registering with a suitable registration authority.
content_id: Content identifier for the program item corresponding to this package. This identifier is managed by each author. A set of content_originator_id and content_id is a content identifier unique to the world.

content_major_version: The main version of the program item corresponding to this package.
content_minor_version: The index of the sub-version of the program item corresponding to this package.
genre_system_id: identifier of the system that classifies the genre. Actually, it corresponds to sub_table_id of the genre table.

major_genre: Index of the main genre of the program item corresponding to this package. This index is an index for the entry of the main genre in the genre table. For example, the main genre may be sports.
minor_genre: The sub-genre index of the program item corresponding to this package. This index is an index for a sub-genre entry in major_genre in the genre table. For example, the sub-genre includes soccer in sports.

rating_system_id: identifier of the system that classifies the audience rank. Actually, it corresponds to sub_table_id of the viewer rank table.
rate_index: Index indicating the viewer rank of the program item corresponding to this package. This index is an index for the viewer rank entry in the viewer rank table.

season_number: Season number of the series. A value of “0” in this field indicates that there is no series season.
serial_number_minus1: Indicates a value that is one less than the number of times in a series of seasons.
prequel_package_id: The package_id of the first package of the program item corresponding to this package. When the value of this field is “0”, it indicates that the program item corresponding to this package is the first time of the series product.

sequel_package_id: The package_id of the next package of the program item corresponding to this package. If this field value is “0”, it indicates that the program item corresponding to this package is the last round of the season of the series.
rebroadcast_package_id: The identifier of the package corresponding to “rebroadcast” for this package.

commentary_channel_count: Number of "screen commentary broadcast" languages for this package.
commentary_language: A 3-byte language identifier according to the ISO 639 standard that specifies the language of “screen commentary broadcasting”.
subtitle_count: Number of “subtitle broadcast” languages for this package.
subtitle_language: A 3-byte language identifier according to the ISO 639 standard that specifies the language of “subtitle broadcasting”.

karaoke_flag: If the value of this flag is “1”, this indicates that the caption is karaoke style.
multiview_coverage_type: When the value of this field is “0”, this indicates that the entire package is a multi-view video, and when it is “1”, only a part of this package indicates a multi-view video.

  multiview_scheme_type: A value of “1” in this field indicates that the “multi-view broadcasting” method is binocular stereoscopic, and a value of “2” indicates that the “multi-view broadcasting” method is multiple. It indicates that the viewpoint is 3D. If it is “3”, it indicates that the “multi-view broadcasting” method is an inward-facing multi-view. If it is “4”, the “multi-view broadcasting” method is , Indicating outward multi-viewing, and “5” indicates that the “multi-view broadcasting” method is multi-viewing in various directions.

PGT_package_info_descriptors_length: Length of the next PGT_package_info_descriptor () syntax loop.
PGT_package_info_descriptor (): Area where additional descriptors can be inserted.

  The syntax of PGT_associated_sub_table () follows the syntax of a general MMT table as shown in Table 12. The meaning of each syntax element is defined below.

table_id: An identifier indicating the type of this table.
version_id: An identifier indicating the configuration of this table. If the configuration of this table is modified due to a standard revision, the value of this field will also change. Based on this value, the receiver determines whether this table is configured so that it can understand the contents of the table. This value is only increased when the table contents are revised incompatible with the existing one.

table_sub_id: Sub-table identifier.
update_version: Version number indicating the content change from the next of this field to the last byte of this sub-table. When the contents of this table are updated, this value increases by one. This value is reset to 0 after the maximum value 255. When the version number of the sub-table stored in the receiver is different from the value, the receiver reads the sub-table again and decodes it.

table_length: The number of bytes from the next of this field to the last byte of this subtable.
sub_table_contents (): Content that changes depending on each sub-table.
CRC_32: The same field as CRC_32 defined in the section syntax of the MPEG-2 system standard.

  PGT_package_info_module () provides a guide for one or more packages when PGT does not include package guide information directly, but indirectly includes package guide information by referring to an external path or file in which package guide information exists. It is a data structure that contains.

The syntax of PGT_package_info_module () is as shown in Table 13, and the meaning of each syntax element is defined below.

PGT_package_info_module_id: PGT_package_info_module () identifier. This identifier is reusable, and unless this identifier is reused, this module always contains information about the same package.
PGT_package_info_module_update_version: Update version of PGT_package_info ().
Each time the content of the next field changes, this field is incremented by 1 regardless of whether or not the identifier can be reused, and is reset to 0 at the maximum value of 255.
PGT_package_info_module_length: The number of bytes from the end of this field to the last byte of PGT_package_info ().
reallocation_flag: If the value of this field is “1”, this module contains information about a package that has the same identifier as this module and that is different from the package contained in the previously received module. It shows that. That is, the identifier is reused.
PGT_package_count_in_this_module: The number of package information contained in this module.
CRC_32: The same field as CRC_32 defined in the section syntax of the MPEG-2 system standard.

  An AAT (Adjunct Asset Table) conveys information related to an adjunct asset. AAT is periodically transmitted as a separate asset constituting a package to which a primary asset corresponding to a target to be synchronized with an auxiliary asset included in AAT belongs.

  The method of synchronizing the primary asset and the secondary asset and the definition of AAT are described in Korean Patent Application No. 2011-0095458. In this specification, for convenience of explanation, the syntax of AAT and the meaning of each field are shown below.

The syntax of AAT is as shown in Table 14, and the meaning of each field is defined below.

table_id: An identifier indicating the type of table. A unique value corresponding to AAT is assigned.
version_id: An identifier indicating the configuration of the AAT. If the table structure is modified due to the standard revision, the value of this field also changes. The receiver refers to this value to determine whether this table is configured to be understood by itself.
sub_table_id: When the entire table is divided into many sub-tables and transmitted, each sub-table is identified.

update_version: Since AAT is periodically transmitted, if the AAT content is different from the AAT content having the same sub_table_id transmitted immediately before, this value is incremented by one. After the maximum value 255, it is reset to 0. When this value changes, the receiver reads the AAT content again and decrypts it.
table_length: The number of bytes from the next of this field to the last byte of AAT. A value of 0 is not used.

  locator_prefix_count: Number of the next locator_prefix. locator_prefix is concatenated to the end of the locator text string provided by adjunct_asset_locator to form a URL. In adjunct_asset_locator, locator_prefix is referenced using the appearance order of locator_prefix as an index. The value OxFF in this field is not used. Therefore, a maximum of 255 locator_prefixes can be included.

locator_prefix_length: Length of locator_prefix text string.
locator_prefix_byte: locator_prefix text string byte. The last null byte of the text string is not included.
adjunct_asset_type: Auxiliary asset type. For example, assign a unique value to each type, such as a web document, widget, interactive application, audio clip, video clip, graphic, text, image, auxiliary media component, etc. This adjuct_asset_type value applies as well for the auxiliary assets in the next syntax loop.

  adjunct_asset_count_minus1: A value one less than the number of auxiliary assets described in the next syntax loop. Up to 256 auxiliary assets can be displayed. When the number of auxiliary assets having the same adjuct_asset_type exceeds 256, description is made using two or more syntax loops.

  adjunct_asset_id: A 48-bit globally unique identifier that identifies the auxiliary asset. Here, uniqueness is maintained only for a certain period, after which the identifier can be reused. In order to become a global identifier, this field is divided into two parts: a 32-bit provider identifier (provider_identifier) and a 16-bit asset identifier (asset_identifier). The provider identifier is registered for each provider by designating a registration organization, and the asset identifier is managed by the provider itself.

execution_attribute: Contains various fields that indicate how the receiver will execute when it receives the auxiliary asset.
execution_on_reception: A flag indicating whether or not to execute immediately after storing the received auxiliary asset in the auxiliary asset cache inside the receiver. If not executed immediately, it may be executed at the time specified by the synchronization method proposed by the present invention, or may be executed by a user's selection or a call from another auxiliary asset. If the value of this flag is 1, execution_entry_point is also set to 1.

  media_service_bound: A flag indicating whether the auxiliary asset is media_service_bound. When the value of this flag is “1”, it indicates that the auxiliary asset belongs to this media service, and the auxiliary asset is automatically terminated when the broadcast channel is switched.

  execution_entry_point: A flag indicating that the auxiliary asset can be executed directly. If the value of this flag is “0”, the auxiliary asset is indirectly executed by another auxiliary asset.

  visible_to_user: When the auxiliary asset navigation function is used to select and execute, or when another auxiliary asset searches the auxiliary asset list through an API (Application Programming Interface) provided by the receiver. A 2-bit field indicating whether or not to make it visible. The meaning of visible_to_user is as shown in Table 15 below.

secure_execution: 2-bit information indicating whether the auxiliary asset is secure. The meaning of secure_execution is as shown in Table 16.
adjunct_asset_priority: A field that indicates the priority order of auxiliary assets. The higher the value of adjunct_asset_priority, the higher the priority. If there are not enough receiver resources to execute the auxiliary asset, the auxiliary asset currently being executed has the lowest priority, or is temporarily stopped or terminated.

adjunct_asset_locator_count_minus1: A value that is one less than the number of locations to read auxiliary assets. As 2 bits, all 4 locations can be indicated. When two or more places are provided, there is a priority according to the order in which adjunct_asset_locator appears. There must be at least one adjunct_asset_locator.
adjunct_asset_locator: Announces information on where to read auxiliary assets.

adjunct_asset_descriptor_loop_length: Number of bytes from this field to the last byte of the descriptor syntax loop.
adjunct_asset_descriptor: This descriptor syntax loop can contain various descriptors.
CRC_32: The same field as CRC_32 defined in the section syntax of the MPEG-2 system standard (ISO / IEC 13818-1: 2007).

  The resource data location information adjunct_asset_locator indicates the location where the auxiliary asset is read. Auxiliary assets are transmitted via the carousel of the broadcast network or downloaded via the Internet. The AAT must include at least one adjunct_asset_locator per auxiliary asset. The receiver first reads the auxiliary asset from the position specified by the adjunct_asset_locator that appears. If an error occurs, the receiver reads the auxiliary asset from the position specified by the next adjunct_asset_locator.

  The syntax of adjunct_asset_locator is as shown in Table 17, and the meaning of each field is defined below. Table 17 includes only the case of the Internet, and in the case of carousel, it depends on the carousel system described in ISO / IEC13818-6: 1998. Therefore, specific matters are not included in Table 17.

  locator_type: An 8-bit field that indicates whether the location where the auxiliary asset is read is an internet or broadcast carousel, the location is a carousel, and what kind of carousel is used when various types of carousels are used together .

locator_prefix_index: An index that specifies one of the locator_prefixes in Table 14. If the value of this field is “OxFF”, this indicates that there is no locator_prefix.
directory_path_length: The length of the next directory path. The last null byte of the text string is not included. If the value of this field is “0”, the directory path is not used.

directory_path_byte: Directory path byte. The last null byte of the text string is not included.
entry_path_length: The length of the path following the first page file. The last null byte of the text string is not included. It only makes sense for auxiliary assets made up of a large number of files, such as web pages. If the auxiliary asset is a single file, the value of this field is “0”.

entry_path_byte: Path byte following the first page file. The last null byte of the text string is not included.
object_count: Number of the next file path. If the value of this field is “0”, the entire directory is designated.
object_path_length: The length of the text string of the next file path. The last null byte of the text string is not included.
object_path_byte: File path byte. The last null byte of the text string is not included.

  As described above, various descriptors can be included in adjuct_asset_descriptor in Table 14. These descriptors include handler_capability_descriptor () that indicates the receiver's ability to process auxiliary assets, adjunct_asset_cache_descriptor () that indicates the amount of memory required for managing the auxiliary asset cache, validity period, etc. Display_position_descriptor () indicating the position on the display, adjunct_asset_name_descriptor () for announcing the auxiliary asset name to be shown to the user, adjunct_asset_icon_descriptor () for notifying the icon of the auxiliary asset to be shown to the user may be included.

  PGT_reference_descriptor conveys the PGT version and position reference information. It may be included in an SMT_M_descriptor syntax loop or in an SMT_S_descriptor syntax loop (SMT_S_descriptor is used for a descriptor in a PPT_body () syntax element group included in SMT-S). If PGT_reference_descriptor is not included in SMT-M or SMT-S, it is considered that the service does not provide package guide information.

The syntax of PGT_reference_descriptor is as shown in Table 18, and the meaning of each field is defined below.

descriptor_tag: A unique value indicating the type of this descriptor.
descriptor_length: Number of bytes from this field to the last byte of this descriptor.
PGT_provider_id: A unique identifier of the organization that provides the PGT. One institution can provide one PGT, and PGT_provider_id is assigned through the registration institution.

PGT_update_version: A version number indicating whether or not the PGT content is changed, and this value is incremented by one when the PGT content is updated. After the maximum value 255, it is reset to zero. When the version number of the PGT stored in the receiver is different from this value, the receiver reads the PGT again and decrypts the content.
number_of_locations: Number of PGT locations provided for this descriptor. The location of the PGT with the same update version follows this field.
MMT_general_location_info (): Specifies the PGT location.

  MMT_general_location_info () is general location reference information, and its syntax and definition are shown in Table 5. If there is one or more MMT_general_location_info () in this descriptor, the receiver tries to access in the order of the list of MMT_general_location_info ().

  MMT_composition_descriptor provides spatial screen arrangement information of assets (including PPT assets) belonging to a certain package based on SMIL. If the screen layout does not change during the playback section of a certain package, the screen layout information may be provided using this descriptor. This descriptor may be included in an SMT_S_descriptor syntax loop or in a PPT_descriptor syntax loop (PPT_descriptor is used for a descriptor in a PPT_body () syntax element group included in the PPT).

The syntax of MMT_composition_descriptor is as shown in Table 19, and the meaning of each field is defined below.

descriptor_tag: A unique value indicating the type of this descriptor.
descriptor_length: Number of bytes from this field to the last byte of this descriptor.
version: When the package composition information is changed, the value of this field is incremented by one, and is reset to 0 after the maximum value 255.
compression_type: Package composition information compression method. A value of “0” in this field indicates that the package composition is not compressed, and a value of “1” indicates that the package composition is compressed by GZIP. The other values are reserved values for later use.
XML_length: Length of the package composition information byte.
XML_package_composition_byte: Package composition information byte. The definition of package composition information is described in ISO / IEC JTC 1 / SC 29 / WG11m19266.

  alternate_package_descriptor is for viewing live broadcasts that have been interrupted due to regular scheduling, if the viewer uses subsequent packages, or if only the latter half of the entire event (eg, golf relay) is broadcast live. This descriptor allows a person to view the event using an alternative package from the beginning. Further, alternate_package_descriptor may be used as an alternative package for an entire package (that is, from the start to the end) regardless of whether this live broadcast is possible.

  MMT_package_descriptor may be included in the SMT_S_descriptor syntax loop or in the PPT_descriptor syntax loop. When the position of the alternative package is a large number of locations, a large number of alternate_package_descriptors may be included in the MMT_package_descriptor.

  The purpose, usage scenario, definition, and usage of this descriptor are described in Korean Patent Application No. 2011-0095665. In this specification, for convenience of explanation, the syntax of alternate_package_descriptor is shown in Table 20, and the meaning of each field is defined below.

descriptor_tag: An 8-bit field indicating the type of this descriptor. A unique value indicating an alternative program descriptor is assigned so that it can be distinguished from other descriptors defined in the MPEG-2 system standard or a broadcast standard using the MPEG-2 system standard.
descriptor_length: An 8-bit field indicating the length of this descriptor in bytes. Indicates the length from the next byte of this field to the last byte of the descriptor.

  alternate_program_id: 8-bit field corresponding to an alternate program identifier. When alternate programs described by alternate_program_descriptor are different from each other, different alternate_program_id is assigned. In the case where guidance is provided so that the alternative program can be viewed before actually starting the live broadcast, the guide information can be transmitted several times for the same alternative program periodically. In such a case, the same alternate_program_id is used subsequently. When all values from 0 to 255 are used, the values already used may be reused.

reserved: As a field reserved for later use, its value is filled with 0x7F.
just_alternate_flag: This indicates that the content included in this descriptor is for an alternative package of the package including this descriptor (regardless of whether it is for live broadcast). If the value of this flag is “1”, future_flag has no meaning, and text_length is always “0”.

  future_flag: A 1-bit field indicating whether the content included in this descriptor is for an alternative program to be viewed in advance or an alternative program to be continuously viewed after the current program ends. When the value of this field is “1”, it indicates an alternative program to be viewed in advance, and when it is “0”, it indicates an alternative program to be subsequently viewed after the end.

time_to_future_live_program: When the future_flag is “1”, a 16-bit field indicating the time until live broadcast is started via this program channel in seconds.
If the value of this field is 0x0000, it means that immediate live broadcast is started or has already started. This value can be used when returning to the live broadcast program of the broadcast channel from the Internet live broadcast service of the alternative package. If the value of this field is OxFFFF, it means that it is impossible to know the time until live broadcast is started via this channel. This value is used when an event scheduled to be broadcast live via this program channel is viewed as an alternative via the Internet live broadcast service, but the live broadcast via this program channel is not known. Used for.

MMT_general_location_info (): General location reference information defined by MMT, the contents of which are shown in Table 5.
text_length: 8-bit field indicating the number of the next text_byte. A value of 0x00 indicates that there is no text string describing the alternative program.
text_byte: A byte constituting a text string describing an alternative program. This field does not include a null byte at the end.

  extension_descriptor (): A descriptor corresponding to a selection item (option) that conveys additional information, and an 8-bit tag value that identifies the type is uniquely identified only in alternate_package_descriptor, This is the first byte of these descriptors. This field is followed by an 8-bit value indicating the length of the descriptor.

  alternate_program_descriptor has the same content as 16-bit alternate_package_descriptor except that the size of descriptor_tag and descriptor_lenth is 8 bytes and the value of descriptor_tag is assigned as the MPEG-2 descriptor tag value. That is, alternate_program_descriptor is obtained by transforming alternate_package_descriptor as an MPEG-2 descriptor.

  alternate_program_descriptor is used for a similar purpose as alternate_package_descriptor, but is included in the descriptor syntax loop next to program_info_length in MPEG-2 PMT. In the case of MPEG-2 TS-based MPEG-DASH, this descriptor may be included directly in the PMT.

  The language_descriptor is used to specify the language of an asset that needs to specify the language to be used. For example, it is necessary to clearly indicate in which language the assets corresponding to audio, subtitles, screen explanation broadcasting, and the like are created. The language_descriptor may be included in the PPT PPT_descriptor syntax loop or asset_descriptor syntax loop of the PPT, and in the SMT_S_descriptor syntax loop or asset_descriptor syntax loop in the SMT-S. When this descriptor is included in the PPT_descriptor or SMT_S_descriptor syntax loop, the language of all assets in the package is specified by this descriptor. When this descriptor is included in the asset_descriptor syntax loop, the language of the asset is specified by this descriptor. The descriptor content applied to the asset takes precedence over the descriptor content applied to all assets in the package. In this specification, for convenience of explanation, the syntax of language_descriptor is shown in Table 21, and the meaning of each field is described below.

descriptor_tag: A unique value indicating the type of this descriptor.
descriptor_length: Number of bytes from this field to the last byte of this descriptor.
ISO_639_language_code: 3-byte language identifier according to the ISO 639 standard.

  The clock_reference_descriptor is used to notify the receiver of the relationship between the encoder clock for media synchronization and the MMT system clock. In MMT, an NTP (Network Time Protocol) type UTC is used as a system clock, and an asset encoder clock is allowed to use a different clock for each asset. The clock used by the asset encoder is identified by clock_reference_id.

  The clock_reference_descriptor must be periodically transmitted in a cycle within 100 ms, and is transmitted to a separate asset. In this specification, for convenience of explanation, the syntax of clock_reference_descriptor is shown in Table 22, and the meaning of each field is defined below.

descriptor_tag: A unique value indicating the type of this descriptor.
descriptor_length: Number of bytes from this field to the last byte of this descriptor.

clock_reference_id: The identifier of the clock used by the asset encoder.
encoder_clock_sample: The value of the asset clock sample corresponding to the next system_clock_time.
encoder_clock_sample: UTC time value in NTP format as the MMT system clock time corresponding to the preceding encoder_clock_sample.

FIG. 5 illustrates an S1 signaling structure according to one embodiment of the present invention.
The six S1 layer messages according to another embodiment of the present invention are organized as follows.

(1) Message about information on tables and notice (ITN):
Such messages convey the ITN table and additionally other tables that can be used for fast access to the package. The role of ITN is similar to MPEG-2 PAT, but has other MMT specific functions. The ITN table contains full information about all other S1 tables. The ITN also has information regarding reception of notifications. Common examples of notifications are emergency alerts, emergency notifications and the like.

(2) Message about MMT Composition Information (MCI):
Such a message carries the MMT CI. This transmits not only full CI but also hierarchical CI.

(3) Message about Clock Reference Descriptors (CRD):
Such a message carries clock reference information used for mapping between the MMT system clock (ie, NTP clock) and any other clock (eg, MPEG-2 or MPEG-4 clock).

(4) Messages for Security Information:
Such a message carries security information used for protecting the MMT content. The security system is DRM, downloadable DRM, and downloadable condition evaluation system (D-CAS) information.

(5) Messages for MMT Package Table (MPT):
Such a message carries an MMT package table (MPT). Perfect or Tier-0 MPT corresponds to the MMT package. This is the global unique identifier of the package, the location of the MMT composition information (MCI), and a complete or partial list of MMT assets belonging to the MMT package (if possible, a layered MPT is used) including. This also includes package type, package name, package short description, parental rate, audio language, text language, target user profile, requested device capability, recording permission and fast play permission. Including package policies. The role of MPT is similar to MPEG2 PMT but has more functions for MMT purposes.

(6) Messages for Device Capability Information Table (Messages for Device Capability Information Table):
Such a message carries a device capability information table (DCIT). The device capability information provides a request and / or recommended device capability for MPEG media content consumption.

In addition, the following three descriptors are defined.
(1) Language descriptor
(2) Clock reference descriptor
(3) D-CAS descriptor

  Hereinafter, the syntax and meaning of S1 layer messages, tables, and descriptors according to another embodiment of the present invention will be defined with reference to FIG.

1. S1 Layer Message, Table, and Descriptor Syntax and Meaning 1.1 Information Table and Notification Information (ITN) Messages Such messages carry an ITN table 505. The role of ITN is similar to MPEG-2 PAT, but has other MMT specific functions. The ITN table contains full information about all other S1 tables.
The ITN also has information regarding notification reception. Common examples of notifications are emergency alerts, emergency notifications and the like.

The ITN message, ie, the message including the ITN table, may further include one or more MMT package tables (MPT) corresponding to the MMT package. The MPT is a globally unique identifier of the package, the location of the MMT composition information (MCI), and a complete or partial list of MMT assets that belong to the MMT package (if possible, a layered MPT is used). including. MPT also includes package type, package name, package short description, parental rate, audio language, text language, target user profile, requested device capability, recording permission and fast play permission. Includes package policy.
If the ITN message contains only one MPT, the media delivery service provides the user with only one package at any fixed time instant. When the ITN table includes multiple MPTs with arbitrary overlap in time series, the media delivery service provides multiple packages to the user at any fixed time instant. If the ITN table does not have time overlap and the corresponding package includes multiple MPTs associated with the same logical channel, the media delivery service provides the user with multiple packages in sequential time order.

  An S layer message with MessageID = 0x00 should include an ITN table. Also, the payload_id of the asset route in the IP application data flow that transmits the S layer message having MessageID = 0x00 is fixed at “0x0000”. The receiver should read and decode the ITN message before reading any other messages.

  ITN messages are typically sent periodically in a very short period, for example 500 ms, in a broadcast environment to ensure a short power-up delay or low zapping time.

1.1.1 ITN Message Syntax and Meaning The syntax of the ITN message is defined in Table 23, and the meaning of this syntax element is provided in Table 23 below. The syntax definition method is based on the method of the MPEG-2 system standard (ISO / IEC 13818-1). In the “Value” column, the indication that there is no loop count can be derived from the length of the table. The same rules apply to other tables herein.

message_id: Indicates the type of the S layer message. The length of this field is 8 bits. The ITN message has a fixed message_id with the value 0x00.
version: S layer message version. The MMT client can determine whether the received S-layer message is new. In particular, this field is useful when S-layer messages are sent repeatedly over the broadcast network. The length of this field is 8 bits.

  length: The length of the S1 layer message. The length of this field is 16 bits. This indicates the length of the ITN message counted in bytes starting from the next field to the last byte of the ITN message. The value “0” is not used at all for this field.

start_time_flag: If the value of this flag is “1”, an additional syntax element start_time is used.
start_time: Start time in NPT of ITN message transmission.
retransmission_period: retransmission time of ITN message. The unit of retransmission_period is 10 ms.
number_of_tables: Number of tables included in this ITN message.
table_id: The table identifier of the table included in this ITN message. This is a copy of the table_id field in the table included in the payload of this ITN message.
table_version: The version of the table included in this ITN message. This is a copy of the version field in the table contained in the payload of this ITN message.
table_length: The length of the table included in this ITN message. This is a copy of the length field in the table contained in the payload of this ITN message. The actual length of the table is table_length + 4.
table (): S hierarchy table. The table in the payload is shown in the same order as the table_id in the extension field.

1.1.2 Syntax and Meaning of ITN Table The syntax of ITN table is defined in Table 24, and the meaning of its syntax elements is provided below Table 24.

table_id: Table identifier of the ITN table.
version: ITN table version. A newer version will override the old version as soon as it is received.
length: The length of the ITN table counted in bytes starting from the next field to the last byte of the ITN table. The value “0” is never used for this field.

  method_flag: Indicates the notification reception method. If the value of this flag is “0”, the notification is transmitted by IP broadcast transmission. If the value of this flag is “1”, the notification is communicated via the interaction channel. An IP address and an IP port number are provided for IP broadcast transmission. For communication via the interaction channel, a URL is provided that allows the client to poll for notifications via the interaction channel.

MMT_general_location_info (): General location reference information defined in Table 25 in section 1.1.3. The actual location depends on the syntax element location_type in MMT_general_location_info ().
MMT_general_location_info () for IP_broadcast_delivery: For IP_broadcast_delivery, only location_type = 0x14 and 0x15 are allowed.
MMT_general_location_info () for poll_URL: For poll_URL, only location_type = 0x0E is allowed.

poll_period: While polling notifications, the client or receiver is expected to poll the notification URL, poll_URL, and all poll_period second.
number_of_tables: Number of information tables whose information is provided in this ITN table.
information_table_id: identifier of the information table for which information is provided in this ITN table. ITN table_id never appears here.
information_table_version: Version of the information table for which information is provided in this ITN table.

  package_path_number: identifier of the logical channel to which the information table belongs. Broadcasters uniquely assign identifiers to logical channels within physical channels. The value “0” has a special usage and is not used as an identifier. If the value of this field is “0”, the information table is channel independent, ie, the information table has service-wide information.

MMT_general_location_info () for location: an address from which the client acquires the information table. Only location_type = 0x0F to 0x13 is allowed.
second_location_flag: When this flag is set, an alternative address from which the client obtains the information table is provided.
table_filter_code_flag: If this flag is set, one or more table filter codes are provided. The table filter code specifies a criterion for grouping a plurality of tables. If there are many criteria to group at the same time, all grouping criteria are applied to the information table.

MMT_general_location_info () for second_location: An alternative address from which the client acquires the information table. Only 0x0F to 0x13 are allowed.
number_of_table_filter_codes: Number of table filter codes for the information table.
language_for_all_table_filter_codes: The language of all table_filter_codes that immediately follow. The language code is a 3-byte language identifier defined in the ISO 639 standard.

  table_filter_code_language_flag: If the value of this flag is “1”, the language for the subsequent table_filter_code is specified separately and overrides the language provided by language_for_all_table_filter_codes. The language code is a 3-byte language identifier defined in the ISO 639 standard.

table_fileter_code_language: The language of table_filter_code that immediately follows. The language code is a 3-byte language identifier defined in the ISO 639 standard.
table_fileter_code_length: byte length of table_filter_code.
table_fileter_code_byte: Byte in table_filter_code.
private_extension_flag: A private extension exists when the value of this flag is “1”.
private_extension (): A syntax element group that acts as a container for ownership or application specific extensions.

1.1.3 MMT_general_location_info () syntax element group
The MMT_general_location_info () syntax element group is used to provide location information. The syntax of MMT_general_location_info () is defined in Table 25, and the meaning of the syntax elements is provided below Table 25.

location_type: This field indicates the type of location information as defined in Table 26.

payload_id: Unique asset path identifier in the IP application data flow.
ipv4_src_addr: IP version 4 source address of the IP application data flow.
ipv4_dst_addr: IP version 4 destination address of the IP application data flow.
dst_port: IP application data flow destination port number.
ipv6_src_addr: IP version 6 source address of the IP application data flow.
Ipv6_dst_addr: IP version 6 destination address of the IP application data flow.

network_id: identifier of a broadcast network that transmits MPEG-2 TS.
MPEG_2_transport_stream_id: MPEG-2 TS identifier.
MPEG_2_PID: PID of MPEG-2 TS packet.
prefix_index: Index to the prefix defined before this syntax element group. If the value of this field is OxFF, no prefix is used.

URL_length: URL length in bytes. The final null (0x00) must not be counted.
URL_byte: Byte data in the URL. The final null (0x00) must not be included.
byte_offset: Byte offset from the first byte of the file.
length: Length in bytes.
message_id: S layer message identifier.
Ipv4_addr: IP version 4 address of the IP application data flow.
Ipv6_addr: IP version 6 address of the IP application data flow.

1.2 Message for MMT Composition Information (CI) MMT Composition Information (CI) is conveyed by a CI message for out-of-band signaling. The CI message can carry a complete CI or a layered CI. When layered CI is transmitted, it is most recommended to transmit layer-0 CI by ITN message in order to reduce the time required for package consumption in the broadcast scenario. When layer-0 CI is transmitted in the ITN message as reference number 510, the CI needs to be encapsulated in an MCI (MMT Composition Information) table before being included in the ITN message.

  When a layered CI mechanism is utilized, a layer-N CI (where N is not 0) is generally transmitted in a CI message with a changed repetition period and a different message identifier.

1.2.1 CI Message Syntax and Meaning The CI message syntax is defined in Table 27, and the meaning of its syntax elements is provided below in Table 27.

message_id: Indicates the type of the S layer message. The length of this field is 8 bits. The S layer message needs to have a separate message_id when transmitting the CI in a separate CI layer for a separate package.
version: S layer message version. The MMT client can determine whether the received S-layer message is new. In particular, this field is useful when S-layer messages are sent repeatedly over the broadcast network. The length of this field is 8 bits.
length: The length of the S layer message. The length of this field is 16 bits. This indicates the length of the CI message counted in bytes starting from the next field to the last byte of the CI message. The value “0” is never used for this field.
start_time_flag: If the value of this flag is “1”, an additional syntax element start_time is used.
start_time: Start time in NPT of CI message transmission.
retransmission_period: retransmission time of this CI message. The unit of retransmission_period is 10 ms.
CI_byte: Byte in CI.

1.2.2 MCI Table Syntax and Meaning The syntax of the MCI table is defined in Table 28, and the meaning of its syntax elements is provided below in Table 28. The MCI table should only be used for perfect CI or stratum-0 CI.

table_id: Table identifier of the MCI table.
version: Version of the MCI table. Newer versions override the old version as soon as they are received.
length: The length of the MCI table counted in bytes starting from the next field to the last byte of the MCI table. The value “0” is never used for this field.
CI_byte: Byte in CI.

1.3 Message about clock reference descriptor (CRD) The clock reference descriptor defined in 1.7.2 is conveyed in the CRD message. One CRD message may include multiple clock reference descriptors.

  When a clock reference descriptor is transmitted in an ITN message, it should be encapsulated in a table structure called a CRD table 520.

1.3.1 CRD Message Syntax and Meaning The syntax of the CRD message is defined in Table 29, and the meaning of its syntax elements is provided below Table 29.

message_id: Indicates the type of the S layer message. The length of this field is 8 bits.
version: S layer message version. The MMT client can determine whether the received S-layer message is new. In particular, this field is useful when S-layer messages are sent repeatedly over the broadcast network. The length of this field is 8 bits.
length: The length of the S layer message. The length of this field is 16 bits. This indicates the length of the CI message counted in bytes starting from the next field to the last byte of the CI message. The value “0” is never used for this field.
start_time_flag: If the value of this flag is “1”, an additional syntax element start_time is used.
start_time: Start time in NTP for CRD message transmission.
retransmission_period: retransmission time of this CRD message. The unit of retransmission_period is 10 ms.
clock_reference_descriptor (): defined in 1.7.2.

1.3.2 CRD Table Syntax and Meaning The CRD table syntax is defined in Table 30, and the meaning of its syntax elements is provided below Table 30. The MCI table should only be used for perfect CI or hierarchy-0 CI.

table_id: CRD table identifier.
version: CRD table version. Newer versions override the old version as soon as they are received.
length: The length of the CRD table counted in bytes starting from the next field to the last byte of the CRD table. The value “0” is never used for this field.
clock_reference_descriptor (): defined in 1.7.2.

1.4 Security messages Security information is conveyed in security messages or ITN messages. When security information is transmitted in the ITN message as reference number 525, it should be encapsulated before being included in the ITN message.

1.4.1 Security Message Syntax and Meaning The security message syntax is defined in Table 31 and the meaning of its syntax elements is provided below Table 31.

message_id: Indicates the type of the S layer message. The length of this field is 8 bits.
version: S layer message version. The MMT client can determine whether the received S-layer message is new. In particular, this field is useful when S-layer messages are sent repeatedly over the broadcast network. The length of this field is 8 bits.
length: The length of the S layer message. The length of this field is 16 bits. This indicates the length of the CI message counted in bytes starting from the next field to the last byte of the CI message. The value “0” is never used for this field.
start_time_flag: If this flag is “1”, an additional syntax element start_time is used.
start_time: Start time in NPT of security message transmission.
retransmission_period: Indicates the retransmission time of this security message. The unit of retransmission_period is 10 ms.
Security_descriptor (): Defined in 1.7.3

1.4.2 Security Table Syntax and Meaning The security table syntax is defined in Table 32, and the meaning of its syntax elements is provided below Table 32.

table_id: Security table identifier.
version: Security table version. Newer versions override the old version as soon as they are received.
length: The length of the security table counted in bytes starting from the next field to the last byte of the security table. The value “0” is never used for this field.
security_descriptor (): Defined in 1.7.2.

Message for 1.5 MPT (MMT Package Table) Referring to FIG. 5, the MMT Package Table (MPT) carries all information about a single package. The S layer message that transmits the MPT is referred to as an “MPT message”. The MPT may be included in an ITN message having another table as reference number 515 or may be transmitted in a separate MPT message.

  For layered delivery of packages with layered CIs, the MPT can be partitioned into multi-layered MPTs. Hierarchy-0 MPT is a basic MPT, and if layered transmission is not used, only layer-0 MPT is transmitted. In the latter case, the tier-0 MPT is a perfect MPT. MPTs in different layers need to have different table identifiers (table_ids). In this standard, 8 different values for MPTtabe-id were assigned so that it could have up to 8 MPT layers. The smaller the MPTtable_id value, the closer the MPT hierarchy is to the basic MPT.

  In order to reduce package acquisition time in a broadcast scenario, it is most recommended to transmit a complete MPT or layer-0 MPT when layered MPT is used in the ITN message.

1.5.1 MPT Message Syntax and Meaning The MPT message syntax is defined in Table 33, and the meaning of its syntax elements is provided below Table 33. The MPT message carries only one perfect MPT or layer-N MPT when MPT layering is used.

message_id: Indicates the type of the S layer message. The length of this field is 8 bits.
version: S layer message version. The MMT client can determine whether the received S-layer message is new. In particular, this field is useful when S-layer messages are sent repeatedly over the broadcast network. The length of this field is 8 bits.
length: The length of the S layer message. The length of this field is 16 bits. This indicates the length of the MPT message counted in bytes starting from the next field to the last byte of the MPT message. The value “0” is never used for this field.
start_time_flag: If the value of such a flag is “1”, an additional syntax element start_time is used.
start_time: Start time in NPT for MPT message transmission.
retransmission_period: retransmission time of this MPT message. The unit of retransmission_period is 10 ms. When hierarchical MPT is used, the transmission_period of the upper layer MPT is generally longer than the transmission_period of the MPT layer below the upper layer MPT.
MMT_package_table (): defined in 1.5.2.

1.5.2 MPT Syntax and Meaning The syntax of MPT () is defined in Table 34, and the meaning of its syntax elements is provided below Table 34.

table_id: MPT table identifier. MPTs in different hierarchies need to have different table identifiers. Eight different values are assigned for MPTtable_id. Of the 8 MPT table_ids, when a layered MPT is used, the table_id for the perfect MPT or the layer-0 MPT is the smallest. For the remaining MPTtable_id, a smaller value means a lower hierarchical MPT.
version: MPT version. Newer versions override the old version as soon as they are received.
length: The length of the MPT counted in bytes starting from the next field to the last byte of the ITN table. The value “0” is never used for this field.
MMT_package_id: Globally unique identifier of the MMT package.
MPT_descriptors_length: Length of descriptor syntax loop. This length is counted from the next field to the end of the descriptor syntax loop. Various descriptors can be inserted into this syntax loop.
MPT_descriptors_byte: 1 byte in the descriptor loop.
package_type: Indicates the type of package. Allowable values are shown in Table 35.

package_name: Package name in multiple languages if possible. The language code is a 3-byte language identifier defined in the ISO 639 standard. The first language in the list is the default.
package_description: Syntax description of the package in multiple languages if possible. The language code is a 3-byte language identifier defined in the ISO 639 standard. The first language in the list is the default.
audio_languages: Audio languages (multiple languages) used in the package. The language code is a 3-byte language identifier defined in the ISO 639 standard. The first language in the list is the default.

text_languages: Text languages (multiple languages) used in the package. The language code is a 3-byte language identifier defined in the ISO 639 standard. The first language in the list is the default.
target_user_profiles: User profiles (multiple profiles) that target the package.
required_device_capability_profiles: Profiles of device capabilities required for package consumption (multiple profiles).

  parental_guidance_flag: If the value of this flag is “1”, the receiver is allowed to show content for what is set by the viewer for child protection rating information (the method of transmission is Don't provide what is being decoded until it can be reliably done. If the value of this flag is “0”, the receiver does not check the rating and provides exclusively what is decoded from this package.

recording_flag: If the value of this flag is “1”, the receiver can store this package in the internal storage unit for later use.
fast_play_flag: If the value of this flag is “1”, the receiver causes the viewer to command high-speed playback of this package.
clock_reference_flag: If the value of this flag is “0”, the clock_reference_id is not provided and by default the MMT system clock is the NTP clock, ie the time base of all assets in this package is the NTP clock. If the value of this flag is “1”, the clock_reference_id field is included next.

protection_scheme_id_flag: If the value of this flag is “1”, the protection_scheme_id field is included next.
clock_reference_id: Clock reference identifier. This field is used to reference the clock conveyed by clock_reference_descriptor () as the default time base for all assets in this package. A value of 0 is not allowed for this field. There are two placeholders for the clock reference identifier in the MPT syntax. One (this field) applies to all assets in this package, and the other applies only to asset entries in the syntax loop. If both fields are included in the MPT syntax, the latter takes precedence.

timescale_flag: If the value of this flag is “1”, the timescale field is included next.
timescale: The time unit for all time stamps used for all assets in this package expressed in multiple units per second. The default value is 90,000. There are two placeholders for the time scale field in the MPT syntax. One (this field) applies to all assets in this package, while the other applies only to asset entries in the syntax loop. If both fields are included in the MPT syntax, the latter takes precedence.

  protection_scheme_id: This field indicates the protection scheme used for all assets in this package. There are two placeholders for the protection scheme identifier field in the MPT syntax. One (this field) applies to all assets in this package, while the other applies only to asset entries in the syntax loop. If both fields are included in the MPT syntax, the latter takes precedence. The value of this field is one of the DCAS_types specified by the D-CAS descriptor in 3.7.3.

protection_scheme_id_flag: If the value of this flag is “1”, the protection_scheme_id field is included next.
MMT_general_location_info () for the CI location: General location reference information about the MMT defined in 1.1.3. For the CI position, only location_type = 0x0F to 0x13 is allowed.
number_of_assets: Number of assets in this MPT.
asset_type: The type of asset. This field is similar to stream_type defined in MPEG-2 PMT but is an extension of it.

  asset_id: Asset identifier. In CI, asset_id is used to refer to an asset. The asset_id defined by the CI is globally unique. This field is a short alias for a globally unique asset identifier. Aliasing is automatically performed by mapping the appearance order of assets in the CI asset list (LoA). When CI layering is used, aliasing is performed within the ordered concatenation of all LoAs from layer O to layer N. In the asset information syntax loop in MPT, the asset_id alias must be expressed incrementally.

asset_clock_reference_flag: If the value of this flag is “1”, the asset_clock_reference_id field is included in the following syntax.
asset_clock_reference_id: Clock reference identifier for the asset. This field is used to reference the clock transmitted by clock_reference_descriptor () as the time base of the asset. If the value of this field is “0”, the NTP clock is used for the asset. If the value of this field is not “0”, the value of this field is one of the clock_reference_id values provided by the clock reference descriptor.

asset_timescale_flag: If the value of this flag is “1”, the asset_timescale field is included in the following syntax.
asset_timescale: The time unit for all time stamps used for assets expressed in multiple units per second. The default value is 90,000.
asset_protected_flag: If the value of this flag is “1”, this asset is protected.
asset_protection_scheme_id_flag: If the value of this flag is “1”, the asset_protection_scheme_id field is included in the following syntax.

MMT_general_location_info () for the asset location: General location reference information of MMT defined in Table 3 in 1.1.3. Only location_type = 0x03, 0x05, and 0x07-0x0D are allowed for asset location.
asset_descriptors_length: The number of bytes counted from the next field to the end of the asset descriptor syntax loop.
asset_descriptors_byte: Byte in the asset descriptor.

1.6 Message about Device Capability Information Table (DCIT) DCIT provides device capability information. When DCIT 530 is transmitted in an ITN message, it needs to be encapsulated in a table structure called a DCIT table.

1.6.1 DCIT Message Syntax and Meaning The syntax of the DCIT message is defined in Table 36, and the meaning of its syntax elements is provided below Table 36.

message_id: Indicates the type of the S layer message. The length of this field is 8 bits.
version: S layer message version. The MMT client can determine whether the received S-layer message is new. In particular, this field is useful when S-layer messages are sent repeatedly over the broadcast network. The length of this field is 8 bits.
length: The length of the S layer message. The length of this field is 16 bits. This indicates the length of the MPT message counted in bytes starting from the next field to the last byte of the DCIT message. The value “0” is never used for this field.
start_time_flag: If the value of this flag is “1”, an additional syntax element start_time is used.
start_time: Start time in NPT of DCIT message transmission.
retransmission_period: retransmission time of this DCIT message. The unit of Retransmission_period is 10 ms. When hierarchical MPT is used, the transmission_period of the upper layer MPT is generally longer than the transmission_period of the MPT layer below the upper layer MPT.
MMT_package_table (): defined in 1.5.2.
DCIT (): Defined by 1.6.2.

1.6.2 DCIT Syntax and Meaning The syntax and meaning of DCIT is defined in Table 37.

1.7 Descriptors The descriptors associated with the S hierarchy table are defined.

1.7.1 Language descriptors Language descriptors are used to identify media assets such as audio, commentary broadcasts, subtitles, etc. The language descriptor can be included in an MPT descriptor syntax loop or an asset descriptor syntax loop in MPT. When a language descriptor is included in the MPT descriptor syntax loop, this specifies the language of all assets in the package. When the language descriptor is included in the asset descriptor syntax loop in MPT, this specifies the language of the asset. The language descriptor included in the asset descriptor syntax loop in MPT has priority over the language descriptor included in the MPT descriptor syntax loop in MPT.

  The syntax of language_descriptor () is defined in Table 38, and the meaning of the syntax element is provided below Table 38.

descriptor_tag: Tag value indicating the type of descriptor.
descriptor_length: Length in bytes counted from the next byte of this field to the last byte of the descriptor.
ISO_639_language_code: 3-byte ISO639 language identifier.

1.7.2 Clock Reference Descriptor The clock reference descriptor is used to specify the relationship between the encoder clock for media synchronization and the MMT system clock. UTC in Network Time Protocol (NTP) format is used as MMT system clock time. MMT allows different clocks to be used for different assets. The clock used by the asset encoder is specified by clock_reference_id.

The clock_reference_descriptors must be periodically transmitted with a clock reference message having a short period, for example, 100 ms.
The syntax of clock_reference_descriptor () is defined in Table 39, and the meaning of the syntax elements is provided below Table 39.

descriptor_tag: Tag value indicating the type of descriptor.
descriptor_length: Length in bytes counted from the next byte of this field to the last byte of the descriptor.
clock_reference_id: Media clock identifier used by the asset encoder. The value “0” is reserved for other purposes and is not used for clock_reference_id.
encoder_clock_sample: The sampling value of the media clock used by the asset encoder corresponding to the next MMT_system_clock_time.
MMT_system_clock_time: UTC time value in the NTP format corresponding to the preceding encoder_clock_sample.

1.7.3 Security Descriptor The security descriptor is used to identify a security system that can be used to protect an MMT asset or package.

The Securtiy_descriptor should be periodically transmitted with a security message or an ITN message.
The syntax of security_descriptor () is defined in Table 40, and the meaning of the syntax element is provided below Table 40.

descriptor_tag: Tag value indicating the type of descriptor.
descriptor_length: Length in bytes counted from the next byte of this field to the last byte of the descriptor.
Security_type: The type of security solution. This represents an access control, digital rights management, downloadable CAS or downloadable DRM solution.
Solution: Indicates which security solution is used for access control, DRM, DCAS or DDRM.
Access_control_server_address: The address of the access control security solution server where the client is authenticated and authorized.
DRM_server_address: DRM solution server address where the client is authenticated and authorized.
DCAS_server_address: The address of the DCAS server where the client can download the DCAS SW after authentication and authorization.
DDRM_server_address: The address of the DDRM server from which the client can download the DDRM SW after authentication and authorization.

  6 and 7 are flowcharts illustrating multimedia reception operations in a receiver according to an embodiment of the present invention.

  6 and 7, first, in step 615, the receiver receives an S1 message transmitted on the current channel. The S1 message is a message for managing all functions required for consumption of MMT assets and MMT items.

  In step 617, the receiver determines whether it is an ITN message included in the found S1 message based on the message ID. For other messages that are not ITN messages, the receiver determines in step 627 whether other messages have been updated. If it is an updated other message, the receiver stores the updated other message and the updated version information of the other message in memory at step 629. In contrast, if it is not another updated message, the receiver proceeds to step 631.

  On the other hand, from the result of determination in step 617, in the case of an ITN message, the receiver determines in step 619 whether or not the ITN message included in the found S1 message has been updated based on the version information. If updated, the receiver determines in step 621 whether at least one table (i) in the ITN message has been updated. If so, the receiver stores the updated at least one table and its version information in the receiver's memory at step 623 and proceeds to step 625. If at least one table (i) in the ITN message has not been updated, the receiver proceeds to step 625. Similarly, if it is determined in step 619 that the ITN message has not been updated, the receiver proceeds to step 625.

  In step 625, the receiver checks all tables. The receiver proceeds to step 631.

  As a result of the examination, the receiver determines in step 631 whether or not the CI hierarchy 0 has been updated.

  If CI layer 0 is updated, the receiver sets CI layer 0 as the integrated CI in step 633. The receiver then proceeds to step 635. If CI layer 0 has not been updated, the receiver proceeds to step 643.

  In step 635, the receiver determines whether the CI layer i version is the same as the CI layer 0 version. If not, the receiver proceeds to step 641. If they are the same, the receiver matches CI hierarchy i with the integrated CI in step 637. In step 639, the receiver determines whether all the CI layers have been checked. If all tests have been completed, the receiver transmits the integrated CI to the CI analyzer at step 641. For example, if the receiver determines that all CI hierarchies have been checked at step 639, the receiver proceeds to step 641. On the other hand, if it is determined in step 639 that the check of all the CI layers has not been completed, the receiver returns to step 635.

  In step 643, it is determined whether MPT hierarchy 0 has been updated. For example, if the MPT hierarchy 0 has not been updated, the receiver ends this process. On the other hand, if updated, the receiver sets MPT hierarchy 0 as an integrated MPT in step 645. The receiver then proceeds to step 647.

  In step 647, the receiver determines whether the MPT layer i version is the same as the MPT layer 0 version. For example, if the layers are not identical, the receiver proceeds to step 653. If so, the receiver matches the MPT hierarchy i with the integrated MPT in step 649. In step 651, the receiver determines whether all MPT hierarchy inspections have been completed. If all inspections are completed, the receiver uses the asset reference in the integrated MPT to locate the asset in the package and transmits the found asset to the asset decoder or asset handler. For example, if the receiver determines in step 651 that all MPT hierarchy checks have been completed, the receiver proceeds to step 653. In contrast, if the receiver determines that the test is not complete, the receiver proceeds to step 647.

FIG. 8 is a block diagram of a transmission apparatus according to an embodiment of the present invention.
As an example of the transmission device, the service providing server 800 includes a service data providing unit 801, a package generating unit 803, and a transmitting unit 805. Although not shown in the drawings, it will be apparent to those skilled in the art that a control unit capable of controlling the components of the transmission device is provided in order to perform the operation of the embodiment of the present invention.
The service data providing unit 801 has all service sources.

The package generation unit 803 generates a package using the tables described with reference to FIGS. 3 and 5.
The transmission unit 805 transmits the generated package to the terminal.
In addition, the transmission unit 805 may transmit the generated package to the terminal via a network having two different physical characteristics, a broadcast network and a broadband network.

FIG. 9 is a block diagram of a receiving apparatus according to an embodiment of the present invention.
As an example, the receiving device may be a terminal, but is not limited thereto.

  The receiving apparatus 900 includes a receiving unit 901, a package analyzing unit 903, and a decoder / reproducing unit 905. Although not shown in the drawings, it is obvious to those skilled in the art that the receiving device or terminal includes a control unit capable of controlling its components in order to perform the operation of the embodiment of the present invention. It is.

  The receiving unit 901 receives a package generated using the tables described with reference to FIGS. 3 and 5 according to the embodiment of the present invention.

The package analysis unit 903 analyzes the components of the received package.
The decoder / playback unit 905 decodes and plays back the content based on the analyzed package components.

  Although not shown in the drawings, data can be recorded, stored and reproduced according to the package generated by the embodiment of the present invention. MMT assets, configuration information, composition information, transport characteristics, package identification information (Package) in a single package on a storage medium (eg CD, DVD, DB, USB, etc.) It is stored to include Identification Information, Asset List Information, Rights Management Information, Transport Timeline Information, and so on. Can be played. In the case of storing and reproducing via a storage medium, it can be more easily stored and reproduced by replacing the URL with storage location information (for example, memory address) in the description of the embodiment.

  The various embodiments described above are understood to be illustrative examples of the invention. All the features described in association with any one of the above-described various embodiments can be used alone or in combination with other described features. Can be used in combination with one or more features of other embodiments of the above, or can be used in combination with other embodiments of the various embodiments. While the invention has been illustrated and described with reference to specific embodiments, forms can be made without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. It will be apparent to those skilled in the art that various modifications are possible in the details.

800 Service Providing Server 801 Service Data Providing Unit 803 Package Generating Unit 805 Transmission Unit 900 Receiving Device 901 Receiving Unit 903 Package Analysis Unit 905 Decoder / Reproducing Unit

Claims (2)

A multimedia content receiving device,
A receiver for receiving a packet including a header and a payload;
A control unit for identifying a control message included in the payload and related to a package configuration of multimedia content,
The control message is
A control message payload including a table containing specific information related to the multimedia content;
Type information of the control message;
Information related to the length of the control message;
Information related to the version of the control message;
Including extension information including configuration information related to the table included in the control message payload;
The table includes a list of assets associated with the package;
The multimedia content receiving apparatus, wherein the specific information includes information related to the package configuration. The multimedia content receiving apparatus according to claim 1, wherein the table includes a table identification character for identifying the table.

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