JP6632749B2 - Multimedia service transmitter - Google Patents

Description

  The present invention relates to a method for providing a multimedia service, and more particularly, to a method for a service provider providing an integrated broadcast and communication service in a heterogeneous network environment to transmit breakdown information regarding the service provided by the service provider.

  The Internet is evolving to broadband, and it is possible to provide 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 ing. In addition, as the existing broadcasting and the Internet broadcasting are more organically combined, a broadcasting-communications-converged multimedia service that provides various services 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. Instead, broadcasts that transmit content only through the Internet without dedicated broadcast channels. Service providers have also appeared. Therefore, regardless of whether a broadcaster uses the dedicated channel and works with the Internet or a broadcaster that uses only the Internet, he / she can view his / her own program contents by transmitting his / her programming information to a large number of viewers together with the program contents. It is necessary to publicize to the viewers so that the viewers can view the contents with a plan. In addition, by providing a “replay” service via the Internet, it is also possible to enable the viewer to follow the content that could not be viewed during the main broadcast. In existing broadcasting, this type of information is called an electronic program guide (EPG), and in the case of the DVB (Digital Video Broadcasting) system standard, in North American systems, PSIP (Program and System Information Protocol), In the European system, it is referred to as 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 a viewer can select a program by using only PSIP. In the European system, PSI and SI can be transmitted together to enable selection of a program only by PSI, but various guide information about the program is further provided via SI. In the specification of the present application, such types of information are also commonly referred to as service breakdown information (Service Specific Information, SSI).

  Unlike the existing broadcasting using the dedicated channel, the Internet broadcasting is provided globally. Therefore, the Internet broadcasting exceeds the regional property of the existing broadcasting and is provided in a region where there is a receiver capable of receiving the Internet broadcasting. For example, it can be accessed via the Internet anywhere in the world. Therefore, in the case of Internet broadcasting, in order to overcome the regional characteristics of existing broadcasting standards roughly classified into North America, Europe, and Japan, the broadcasting must be provided in a single system unique in the world, and the complexity of the receiver Unnecessary increase in the degree can be prevented. From such a point of view, SSI further requires a single standardization.

  It is anticipated that future broadcasting-communication integrated broadcasting systems will be reorganized around the Internet. That is, not only the 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 by the receiver. The receiver obtains the SSI through a broadcast channel or the Internet, and uses the SSI to control broadcast reception. Internet broadcasting companies that do not use a dedicated broadcasting channel naturally transmit SSI via the Internet.

  Therefore, there is a need for an apparatus and method for providing a format in which a service provider providing a broadcast-communications-converged service in a heterogeneous network environment including the Internet transmits the breakdown information regarding the service provided by the service provider.

  The information is presented as background information to aid in understanding the description of the present invention. No determination or reference can be made as to whether the present invention can be applied as prior art.

  The features of the present invention address at least the above problems and / or disadvantages and provide at least the advantages described below. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a format in which a service provider providing a broadcast-communication convergence service can transmit breakdown information regarding a service provided by the service provider in an environment of a heterogeneous network including the Internet. .

  According to one aspect of the present invention, there is provided a method for receiving a multimedia service. The method comprises the steps of: receiving service breakdown information on at least one multimedia service provided from a different network; selecting one service with reference to the service breakdown information; Receiving. 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 service map table transmitted through one logical channel. It may include one of the second service map tables containing information about the service. The first service map table and the second service map table may each include asset association information.

  According to another aspect of the present invention, a method for transmitting a multimedia service is provided. The method includes transmitting service breakdown information on at least one multimedia service provided from a different network, and transmitting 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. The first service map table and the second service map table may each include asset association information.

  According to yet another aspect of the present invention, there is provided an apparatus for receiving a multimedia service. The apparatus includes a receiving unit that receives service breakdown information on 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 receiving 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. The first service map table and the second service map table may each include asset association information.

  According to yet another aspect of the present invention, there is provided an apparatus for transmitting a multimedia service. The apparatus comprises: a transmitting unit that transmits service breakdown information on 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 transmitting 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. The first service map table and the second service map table may each include asset association information.

  According to yet another aspect of the present invention, there is provided a method for receiving a multimedia service. 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 table for the MPT may include an asset list belonging to a package.

  According to yet another aspect of the present invention, there is provided an apparatus for receiving a multimedia service. 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 table for the MPT may include an asset list belonging to a package.

  According to yet another aspect of the present invention, a method for transmitting a multimedia service 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 table for the MPT may include an asset list belonging to a package.

  According to yet another aspect of the present invention, there is provided an apparatus for transmitting a multimedia service. The device 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 table for the MPT may include an asset list belonging to a package.

  Other features, advantages, and salient features of the present invention will become apparent to one of ordinary skill in the art from the following detailed description, taken in conjunction 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 about the service provided by the service provider by itself. To allow the viewer to easily select the desired broadcast content.

FIG. 4 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 showing the structure of SSI in Internet broadcasting. FIG. 3 is a diagram illustrating a logical structure of an SSI according to an embodiment of the present invention. FIG. 3 is a diagram illustrating an example of using SSI in MPEG-2 TS-based broadcasting. FIG. 4 illustrates an S1 signaling structure according to an embodiment of the present invention. FIG. 5 is a diagram illustrating a multimedia receiving operation in the receiver according to the embodiment of the present invention. FIG. 5 is a diagram illustrating a multimedia receiving operation in the receiver according to the embodiment of the present invention. FIG. 3 is a diagram illustrating a structure of a transmission device according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a structure of a receiving device according to an embodiment of the present invention.

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

  The following description, with reference to the accompanying drawings, is provided to aid a comprehensive understanding of embodiments of the invention as defined within the following claims and equivalents thereto. . Although various specific details are included to assist in this understanding, they are merely one example. Accordingly, it will be apparent to one having ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the invention. In addition, from the standpoint of clarity and conciseness, detailed descriptions of functions and configurations that are 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 meanings in the literature, but are used exclusively by the inventor to enable a clear and consistent understanding of the invention. Therefore, the description of the embodiments of the present invention, as defined by the appended claims and their equivalents, is intended to be illustrative only and not limiting of the objects of the invention. Will be apparent to those of ordinary skill in the art.

  It should be understood that throughout this specification, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. . Thus, for example, "elemental surface" includes one or more of such surfaces.

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

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

  Background broadcast service: Supports foreground media services, such as carousel for file download, pre-download via the Internet, etc. Media exposure service not exposed.

  Video service: Video is a 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 main service, and associated video or images, interactive applications, and other additional data may be provided.

  Interactive application: During the consumption of a video or audio service, it is called as needed to provide information to the viewer and control the media service in response to the viewer's response, or to the media operator's server. Software for transmitting information is collectively referred to as declarative and procedural languages. Called by the media provider in connection with a currently consumed video or audio service, or called by a media provider regardless of the media service currently being consumed. Also, an interactive application already stored in the receiver's cache and recognized by the viewer may be invoked at the viewer's request.

  Regular media: Media that must be provided due to 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 may not be provided due to the requirements of the media service, but are 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 that constitutes a medium. 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 cannot independently constitute one medium, but that, together with other media components, constitutes a piece of media. For example, in a 2D / 3D mixed time service, a left-eye image is always provided as a 2D image among a left-eye image and a right-eye image, and a right-eye image provided only in a stereoscopic video section is: Auxiliary media component.

  Asset: encoding data about a media component. Here, encoding refers to compression encoding, encoding conforming to a standard format, and the like.

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

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

  Program: One instance of a media service (eg, the entire contents of one broadcast channel (logical channel)).

  Program item: The content of a program at a certain time interval. For example, when a start advertisement, an intermediate advertisement, and a last advertisement are mixed and transmitted in one movie, the content is a content of 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 connecting a plurality of non-inclusive program items (which may include inclusive program items) on the time axis.

  Package: encoded data relating to a program item. It includes control information for associating a plurality of assets with transmission, decoding, playback, etc. of these assets.

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

  Attached information: means additional information such as control information and explanation information on an asset. The attachment information is a logical term, and is actually included in the header of a plurality of layers of the transmission hierarchy, and is called header information in this case.

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

  Non-stream asset: An asset that is not a stream asset.

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

  Logical channel: A path for transmitting one encoded program. For example, in an existing digital TV system based on MPEG-2 TS (Transport Stream), a data transmission path specified by a 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., correspond to a logical channel.

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

  IP application data flow: One IP application data flow is specified by a source address and a 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. You.

  Asset Path Identifier (APID, Asset Path Identifier): Identifier of the asset path (eg, information carrying the asset). One IP application data flow is composed of various asset paths, and each asset path is uniquely identified within the one IP application data flow by APID.

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

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

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

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

  Guide information target period: The SSI needs to guide the service breakdown after a certain period of time, present, and after a certain period (for example, half a month). However, the service breakdown broadcast in the past may not be directly included in the SSI. In this case, the receiver deletes the previously stored service breakdown for a certain period of time (for example, half a month). Without saving, you may save.

  Validity 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 a content different from the organization content included in the known SSI, means for enabling the transmitter and the receiver to modify the known SSI must be provided.

  Means for transmitting guide information: It is necessary to transmit the entire or a part of the SSI via one or more media such as wired / wireless Internet, terrestrial channel, satellite channel, cable, etc. as necessary.

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

  Minimization of channel acquisition time: SSI needs to have a structure capable of minimizing channel acquisition time. Here, the “channel acquisition time” means a time from when power is applied or after a channel is changed to when video and audio are reproduced.

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

  Backward compatibility with existing broadcasting: It is necessary to use SSI in existing broadcasting 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. New versions of receivers that support SSI can take advantage of SSI.

  Support for many small screens in one screen: SSI needs to support many small screens in one screen. In this case, a positioning function on the spatiotemporal space of the small screen is included. For example, when broadcasting a baseball game live, it is necessary to include all small screens showing pitchers, batters, specific infielders, the entire stadium, and the like in the entire screen.

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

  Guide support for multilingual broadcasting, subtitle broadcasting, screen commentary broadcasting, and sign language broadcasting: SSI provides auxiliary content that can improve accessibility, such as audio broadcasting, caption broadcasting, screen commentary broadcasting, and sign language broadcasting in various languages. If included in the program, you need to guide this.

  Guide to content usage restrictions: SSI needs to guide some restrictions on the use of content. Such restrictions may include content rank (prohibition of viewing below a certain age), recording possibility, arbitrary accessibility, high-speed playback / reverse playback, pay-per-view, monthly flat-rate billing, 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 at each content component. In addition, the SSI needs to guide the transmission of the content by using one or more dedicated broadcast physical channels and the Internet independently, or partially or entirely.

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

  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 guide on auxiliary data, such as the expression of an additional finite length stream to represent the formula 3D video for a period of time.

  On the other hand, the SSI is provided by a broadcasting company or a broadcasting company group. Since terrestrial broadcasting companies, cable broadcasting companies, satellite broadcasting companies, Internet broadcasting companies, etc. operate independently, they will independently transmit their service details unless sharing and integrating transmission of service details are mutually agreed upon. There is only. However, when there is such a contract, the service breakdown may be integrated and guided to a broadcasting company group which is a group of broadcasting companies participating in the contract. If the amount of information in the service breakdown guide is large, it takes a long time to download it on the receiver, so the delay time until the viewer browses the service breakdown guide increases, and the changed service breakdown guide is downloaded However, a burden is also increased, and a method for overcoming such a point is required.

  In a broadcasting system based on the existing MPEG-2 standard, PSI (Program Specific Information) provided by the MPEG-2 system standard (ISO / IEC 13818-1) is insufficient for a service breakdown guide. Defines and enforces additional service and system guide information. Program and System Information Protocol (PSIP) of ATSC (Advanced Television Systems Committee) and SI of DVB are PSI. In the case of the ATSC PSIP, since it contains information that replaces the PAT (Program Association Table) and PMT (Program Map Table) in the MPEG-2 PSI, the receiver does not need to decode the PAT or PMT, and the It is designed to receive.

  Unlike broadcasting through a dedicated channel that multiplexes and transmits many programs in one physical channel, in the case of Internet broadcasting using only the Internet, various programs are not multiplexed in one IP application data flow. That is normal. Of course, if necessary, various programs may be multiplexed in one IP application data flow. However, in the scheme proposed according to the embodiment of the present invention, one program is stored in one IP application data flow. Assume that you only send. Also, a case where a program component is separately transmitted through many different physical channels due to the limitation of the bandwidth of the physical channel does not correspond to Internet broadcasting. Under such conditions, the SSI for Internet broadcasting can be very 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 checks the breakdown of the physical channel from the ATSC PSIP or DVB SI, and when tuning a specific physical channel, checks the breakdown of the program in the physical channel from the PAT in the MPEG-2 PSI. Upon selecting a particular program, the receiver can identify the program component from the PMT in MPEG-2 PSI. In the ATSC system, the components of a specific program can be directly identified from the PSIP information.

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

  The receiver can reproduce the program by checking 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 not possible to know in advance when the power of the receiver will be turned on, when to access the Internet broadcast, etc., the service breakdown information needs to be transmitted periodically. The shorter the cycle, the better. Usually, it is preferable to keep the time within 500 ms. If the amount of service breakdown information is large, it is inefficient because a large number of packets must be transmitted at the same time interval in order to transmit the information in a short cycle. 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 at a longer period, or otherwise at the request of the receiver.

  FIG. 3 illustrates a logical structure of an SSI according to an embodiment of the present invention. For example, FIG. 3 illustrates a logical structure of an SSI for a broadcast-communications-convergent broadcast 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 a combination of the structures of FIGS. 1 and 2, and a service map table for multiple packages (SMT-M) 301 is transmitted via a dedicated broadcast physical channel. The service map table for a single package (SMT-S) 309 is used when broadcasting a plurality of logical channels, and broadcasts a single logical channel via a dedicated broadcast physical channel or uses only the Internet. Used when broadcasting mainly using the Internet. As an example of broadcasting using the Internet mainly, when a broadcaster using both the dedicated physical channel and the Internet performs Internet broadcasting, data transmitted via the dedicated physical channel is transmitted by the Internet broadcasting as necessary. Use cases. For example, when a certain content is broadcast on the Internet due to the limitation of the bandwidth of the dedicated channel, the auxiliary data additionally used for the content may share the content transmitted via the dedicated channel. In such a case, a receiver that can only access the Internet cannot utilize the auxiliary data, but a smart TV receiver that has both a tuner of a dedicated channel and an Internet access device has a main content. The auxiliary data can be received via the Internet and, in the case of auxiliary data, via a dedicated channel, and can be comprehensively provided to the viewer.

  The SMT-M is a simple guide content for all programs in the physical channel transmitting the SMT-M information, and PPTs (Package Packing Tables) 307-1 to 307 including information on each program item currently being broadcast. -n location reference information, and further includes location reference information and version information about a PGT (Package Guide Table) 305 that includes guide information on all programs provided by the broadcaster.

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

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

  For example, when various integrated delta modules with PGT version differences from 1 to N (where N represents a number corresponding to one or two days) are provided together, the burden of downloading the receiver is significantly increased. 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 have been added / updated / deleted. The added or updated module is downloaded and the content to be deleted should be deleted, and if the PGT version is the same, the receiver needs to download or decrypt the PGT newly. There is no.

  Each module of the PGT contains guide information about one or more program items or corresponding packages, or an additional associated table (eg, a rating table) required for decoding the PGT. )including. Since the guide information on the package included in the PGT includes the position reference information on the PPT, the viewer can select a program using the PGT, or can make a scheduled recording. Instead of guiding the outline of the program content with long text information, by guiding the URL (Uniform Resource Locator) of the program homepage on the Internet, the amount of information to be included in the PGT is reduced, and the program content that depends only on text is reduced. Aside from the guide, various program guides using HTML pages and services such as "preview" and "replay" are enabled.

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

  Referring to FIG. 3, SMT-S is similar in structure and function to PPT. In the case of Internet broadcasting, since there is usually only one program in one IP application data flow, there is no need to acquire program access information in two steps, SMT and PPT. The same applies to a case where only one program item is broadcast in one physical channel dedicated to broadcasting. SMT-S shortens the channel acquisition time by combining the functions of SMT and PPT into one. Within the SMT-S, a simple guide on the Internet broadcast channel or the logical channel itself, a simple reference 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 information related to the assets 311-1 to 311-K that constitute the. Therefore, the SMT-S integrally transmits a logical channel guide, a program item guide, and program item component information.

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

  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, 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 corresponds to this. However, in this case, the PGT must always guide each program item.

  The location of the PGT provided by the SMT-M may be one of a stream in a physical channel transmitting 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 includes a stream in a physical channel for transmitting the PPT, a stream in another physical channel, a stream in an IP application data flow, and an Internet URL (MPEG-DASH URL). ) May be used. When the program item transmitted through the broadcast-only physical channel broadcasts only a part of the event that the viewer desires to view for various reasons, an alternative to viewing the entire event is available. It may include information about program items. For example, if the live broadcast of an HDTV baseball game is interrupted due to a regular schedule, it is possible to guide an alternative program item based on MPEG-DASH which is a low-resolution video but allows the viewer to continue to watch it. .

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

  When the location of the PGT is the Internet URL, the receiver accesses the URL at the time of necessity or at a designated cycle to access the entire PGT or an updated or added module of the PGT. 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 changes from many to one, a physical channel including only SMT-M may include only SMT-S. In this case, since the values of table_id are different between SMT-M and SMT-S, the receiver can easily distinguish them.

  One of the main functions of the SMT-M and the SMT-S is to transmit the latest version information of the PGT and the location reference information of the PGT. The receiver may download the latest PGT using the latest version information of the PGT and the location reference information of the PGT included in the SMT-M and the SMT-S. If the latest version of the PGT included in the SMT-M and the SMT-S is the same version as the PGT already stored in the receiver, the receiver performs viewing and listening based on the already stored PGT content. Allows the user to select a program item. If the latest version of the PGT included in the SMT-M and the SMT-S is different from the PGT content already stored in the receiver, the updated PGT is downloaded until the storage in the receiver is completed. Prevent viewers from selecting program items based on PGT.

  In an actual system, the PGT may not be transmitted, but in such a case, the viewer may mainly select the program item based on the SMT-M or SMT-S.

  When the receiver is installed for the first time, since there is no PGT downloaded, a physical channel dedicated to broadcasting 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 viewer downloads the program item based on the PGT after the PGT is downloaded using the PMT position reference information of the SMT-M or the SMT-S confirmed for the first time. Make a choice. If the broadcast system does not provide a PGT, the receiver checks all logical channels provided by the broadcast system by continuously performing an automatic channel search, and then the viewer To be able to navigate.

  Subsequently, when the receiver used is turned off and then turned on again, the program item of the previously viewed logical channel is first reproduced, and 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 the logical channels or decodes the PGT information to select a desired program item from the program items currently being broadcast.

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

  When the viewer selects a certain program item based on the PGT program item guide, the receiver accesses the logical channel on which the program item is actually transmitted, and is currently broadcasting on the logical channel. Show the program item. Very rarely, from the point in time when the viewer refers to the PGT program item guide to select a program item, to the point immediately before decrypting the actual SMT-M or SMT-S of the program item in question. 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 urgent organization is changed to the previous version. If it 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, the asset referenced by the SMT-S or PPT may actually be a media asset or may be another PPT. However, the PPT referred to by the SMT-S or the PPT does not allow a double recursive reference that again refers to another PPT. When SMT-S or PPT 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 within one program item and is fixed, if this amount is not large, the MMT (MPEG Media Transport) composition information is transmitted by being included in the descriptor in the PPT. You may. When the screen layout is switched according to time within one program item, the MMT composition information is transmitted as a timed asset. On the other hand, when the screen arrangement is not switched according to time within one program item, but the amount of composition information is large, the MMT composition information may be transmitted as an untimed asset without time information.

  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 existing broadcast receivers and receivers that support MMT.

  Referring to FIG. 4, in this example, two programs exist in one TS. Existing broadcast receivers decode MPEG-2 PAT, MPEG-2 PMT1, and MPEG-2 PMT2 to receive the program. A receiver supporting the MMT decrypts the MMT SMT-M, the MMT PPT1, and the MMT PPT2 to receive the program. Of course, the PID of the TS packet carrying the MMT SMT-M must be pre-assigned as a fixed value, and the SMT-M and 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. When broadcasting a plurality of logical channels via a dedicated broadcast physical channel, SMT-M (Service Map Table for Multiple packages) is a dedicated physical channel of the broadcast and uses a PPT of PPT corresponding to all program items currently being broadcast. Used to communicate the location and the version and location of the program guide. Preferably, the SMT-M is transmitted in a cycle of 500 ms, so that 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 transmitting SMT-M 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 the content described in the “type” column of Table 1 conforms to the MPEG-2 system standard. The loop count not shown in the “value” column of Table 1 is a value derived from the 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: identifier indicating the type of table. A unique value corresponding to SMT-M is assigned.
version_id: identifier indicating the configuration of this table. This value changes when the table configuration is modified by the standard revision. The receiver determines, based on this value, whether the table is configured so that it can understand the contents of the table itself. This value is incremented only when the contents of the table are incompatible with the existing one.

table_length: The number of bytes from the next byte of 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 agency.

  SMT_update_version: Since the SMT-M is transmitted periodically, if the content of the SMT-M is different from the content of the SMT-M 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 and decrypts the contents of the SMT-M again.

  SMT_prefix_count: number of subsequent SMT_prefix. SMT_prefix is concatenated before a text string included in SMT-M to form a URL. When trying to refer to the SMT_prefix, the SMT_prefix is referenced using the appearance order of the 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: SMT_prefix text string length.
SMT_prefix_byte: Byte of SMT_prefix text string. It does not include the last null byte of the text string.

  SMT_M_descriptors_length: Indicates the length of the SMT_M_descripor syntax loop immediately following 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: Number of packages currently being transmitted via this broadcast channel.
package_path_number: A package path number for distinguishing a logical channel in a certain broadcast channel. The value "0" is not used. The package_path_number is uniquely assigned within a physical channel by one broadcasting company or a group of broadcasting companies.

  package_id: The identifier of the package currently being transmitted via this virtual channel. The package_id is a value assigned to each package by a broadcaster, 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 period of time.

  simple_location_type: Specifies the type of the location reference information about the 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. If the value of this field is “0”, the asset path that carries the PPT is designated as APID, and if the value of this field is “1”, the MPEG-2 TS that carries the PPT is defined in MPEG-2. Designated PID.

PPT_APID: identifier of the asset path that carries the PPT in the IP application data flow.
PPT_PID: PID of 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.

  An SMT-S (Service Map Table for a Single package) is a program item that broadcasts one logical channel via a dedicated broadcast physical channel, uses only the Internet, or broadcasts mainly using this. It is used to transmit simple guide information about the corresponding package, location reference information for more detailed program guide information, configuration of program items, and location reference information of 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 path having the same APID, but are identified by table_id.

Table 2 shows the syntax of SMT-S.

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

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

table_length: Number of bytes from the next of 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 broadcasting service. It is necessary to assign a unique identifier to each broadcaster's IP application data flow via a registration agency.

  SMT_update_version: Since the SMT-S is transmitted periodically, if the content of the SMT-S is different from the content of the SMT-S 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 the value changes, the receiver reads and decrypts the contents of the SMT-S again.

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 the PPT in the 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 transmitted via this virtual channel. The package_id is a value assigned by a 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 period of time.

  prefix_count: the number of subsequent prefixes. The prefix is concatenated at the end of the text string to form a URL. When trying to refer to a 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: The length of the 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 descriptor syntax loop immediately following this field is expressed as the number of bytes from this next byte to the last byte of the descriptor syntax loop. Although various descriptors may be included in descriptor (), when the PPT_body () syntax element group in Table 3 is included in SMT-S, PGT_reference_descriptor () is included in this descriptor (). It may be.

  parental_guidance_flag: If the value of this flag is "1", the receiver does not play the content restored from the package until the PGT is decrypted and the correct audience rank applied to this package is confirmed. . If the value of this flag is “0”, the receiver reproduces 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: If the value of this flag is “1”, the viewer can make any access to this package.

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

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

  timescale: The time unit applied to the various time stamps of the asset is expressed as the number of time units per second. The default value is 90,000. The timescale field is found in two places in the PPT_body (), but the first one is the value that applies to all assets belonging to the package, and the second one 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 encryption scheme for the asset. The protection_scheme_id field is found in two places in the 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 identifier of the clock used by the asset encoder. The clock_referece_id field appears in two places in the PPT_body (), but the preceding one is the value that applies to the entire asset 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 of the assets belonging to the same group. For example, for multilingual support, audio in the A language and audio in the B language may belong to the same asset group.

  level_of_mandatory_playing: A value indicating whether one asset in the asset group must be played indispensable. If the value of this field is “0”, the receiver must essentially play one asset of this asset group. If the value of this field is not "0", the receiver does not have to play assets belonging to the asset group due to its capabilities. However, the higher the value of this field, the lower the importance. The receiver may omit the asset group with a smaller value in this field and need not play the asset group with a larger value in the field.

number_of_assets_in_group: Number of assets belonging to this asset group.
asset_type: Asset type. This field is similar to stream_type in MPEG-2 PMT, but is an extended field. If the asset_type is PPT, this asset is called a PPT asset. However, a double recursive reference that refers to another PPT asset in the PPT asset included in the SMT-S or PPT is not allowed.

asset_id: Asset identifier. asset_id is used to point to the asset in MMT_package_composition_descriptor ().
default_selection_flag: When the value of this flag is “1”, it indicates that the asset is an asset that is preferentially recommended in the asset group to which the asset belongs. Of the assets belonging to the same asset group, the value of this flag needs to be set to “1” for only one asset. If the value of this flag is “0” for all assets belonging to the same asset group, the receiver regards the asset appearing first as the asset recommended with priority.

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

scheme_id_flag: When 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 as shown in Table 5.
asset_descriptors_length: The number of bytes from the end of this field to the last byte of the descriptor syntax loop.
asset_descriptor (): Descriptor of the asset.

  PPT_asset () is a syntax element group used to include another package in one 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 as shown in Table 5.

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

AMID: The identifier of the module in the asset path.
APID: The identifier of the asset path in the IP application data flow.
Ipv4_src_addr: IP version 4 source address of 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 broadcast network identifier for transmitting the MPEG-2 TS.
MPEG_2_transport_stream_id: 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 decrypting this field. If the value of this field is OxFF, it indicates that there is no prefix.
URL_length: Length of URL. The last null byte (0x00) of the text string is not included.
URL_byte: Byte of URL. It does not include the last null byte of the text string.
byte_offset: Byte offset from the beginning of the file.
length: Length in bytes.

  In the case of broadcasting using a physical channel dedicated to broadcasting, a PPT (Package Packing Table) is a simple guide information for a program item and a package corresponding thereto, location reference information for more detailed program guide information, and a program item. And the position reference information of the component. Preferably, the PPT is transmitted in a period within 500 ms.

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

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

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

  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 contains information that enables such sorting. The transmission side may arrange and transmit the guide information of the program items according to a predetermined rule.

  The program item is identified by the 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. The PGT_provider_id needs to designate a registrar and assign it at the request of each broadcaster or broadcaster group. In the case of package_id, each broadcaster or broadcaster group uniquely assigns it to its own program item. The package_id is a 16-bit value that can identify a finite number of program items, and therefore needs to be reused after a certain period. 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 becomes an identifier unique to a certain program item or a package corresponding to the program item until all package_id_recycle_numbers are exhausted. For example, assuming that it takes about one year to exhaust the package_id, the uniqueness is guaranteed for about 256 years because the package_id_recycle_number is 8 bits.

  The PGT includes an identifier of a broadcasting company or a group of broadcasting companies providing the PGT, an updated version, a URL of a homepage of the broadcasting company or the group of broadcasting companies 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, as a form of delta information, only a part that is different from the past PGT version that can be distinguished from the current PGT version. If the 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.

Table 8 shows the syntax of the PGT.

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

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

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

table_length: The number of bytes from the next of 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 concatenated to the end of the text string included in the PGT. When trying to refer to a prefix, the prefix is referred to by using the appearance order of the prefix as an index. The value of OxFF is not used as an index value. Therefore, it may include up to 255 prefixes.

PGT_prefix_length: Length of the text string of PGT_prefix.
PGT_prefix_byte: PGT_prefix text string byte. It does not include the last null byte of the text string.
PGT_provider_homepage_URL_prefix_index: Index for the prefix of the homepage URL of the institution that provides PGT. If this field specifies one of the preceding prefixes and the value of this field is OxFF, it indicates that there is no prefix text string.

PGT_provider_homepage_URL_length: Length of the postfix byte in the homepage URL of the institution that provides PGT.
PGT_provider_homepage_URL_byte: ASCII text value of postfix in the homepage URL of the institution that provides PGT.
PGT_descriptors_length: The length in bytes of the next descriptor syntax loop.
PGT_descriptor (): Descriptor for association 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: If the value of this flag is "0", the logical channel information is directly included in the PGT, and if 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, and if the value of this flag is "1", it 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 when creating a PGT_delta_update_module and the current PGT version. 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 the PGT of the previous version as much as PGT_update_delta and the current version of PGT.

  PGT_logical_channel_info_update_version: version of PGT_logical_channel_info () defined in Table 10. MMT_general_location_info () immediately next specifies the position 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: identifier of PGT_package_info_module ().
PGT_package_info_module_update_version: Version of PGT_package_info_module (). The next 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: Version of PGT_associated_table_info_module (). The immediately following MMT_general_location_info () specifies the location of PGT_associated_table_info_module ().

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

PGT_associated_sub_table (): Sub table in the table attached to the PGT.
PGT_delta_update_info_module () is a syntax element group that includes only updated information among the contents of the PGT. PGT_delta_update_info_module () may optionally include updated logical channel information, updated respective package information, and updated respective associated sub-tables.

  When the PGT_update_version is different from the PGT version stored therein, the receiver decodes the PGT contents up to the PGT_descriptor () loop, and then subtracts the PGT version stored therein from the PGT_update_version. It is determined whether or not there is, and if there is PGT_update_delta, the PGT update can be completed by decrypting the PGT_delta_update_info_module ().

Table 9 shows the syntax of PGT_delta_update_info_module ().

In Table 9, the meaning of each syntax element is as follows.
PGT_update_delta: A value corresponding to the difference between the reference past PGT version and the current PGT version when creating the 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 on logical channel information is included.
update_package_info_flag: When the value of this flag is “1”, it indicates that update information on package information is included.
update_associated_table_flag: When the value of this flag is “1”, it indicates that update information on the table information attached to the PGT is included.

PGT_logical_channel_info (): logical channel information defined in Table 10.
PGT_package_update_count: 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 (): Sub table in the table attached to the PGT.

  PGT_logical_channel_info () is a syntax element group corresponding to metadata of all logical channels provided by the PGT provider among PGT contents.

  Table 10 shows the syntax of PGT_logical_channel_info (). Here, PGT_logical_channel_index which is a syntax loop index is an index used in 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 increased by one, and is reset to 0 at 255.

PGT_logical_channel_info_length: The number of bytes from the next byte 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. If the value of this field is "0", it indicates the Internet, if it is "1", it indicates a terrestrial wave, if it is "2", it indicates a satellite, and if it is "3", it indicates a cable.

major_channel_number: major channel number.
minor_channel_number: minor channel number.
service_id: MMT service identifier.

  package_path_number: A package path number for distinguishing a logical channel in a certain broadcast channel. The value "0" is not used. The package_path_number is uniquely assigned within a physical channel by one broadcasting company or a group of broadcasting companies.

  test_channel_flag: Indicates that this logical channel 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 via a cable, the value of this flag is set to “1” for the logical channel.

  channel_protection_type: indicates the encryption mode applied to this logical channel. If the value of this field is “0”, it indicates that it is not encrypted, if it is “1”, it indicates that all packages in this logical channel are encrypted, and if it is “2”, It indicates that only some of the assets belonging to the packages in this logical channel or only some of the partial / whole assets have been encrypted, and “3” indicates that only some of the packages have been 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. If the value of this field is "3", for example, it indicates that only some packages transmitted 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 sub-channel number.
MMT_general_location_info (): Designates the position of PPT or SMT-S corresponding to this logical channel.
descriptors_length: Length of the next descriptor syntax loop.
descriptor (): Descriptor of logical channel information and association.

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

In Table 11, the meaning of each syntax element is as follows.
package_id: The identifier of the package currently being transmitted via this logical channel. 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 period of time.
PGT_package_info_update_version: Version of PGT_package_info (). This value is increased by one each time the content of the package information changes, and is reset to 0 at 255.

PGT_package_info_length: The number of bytes from the next of this field to the last byte of PGT_package_info ().
package_id_recycle_number: The value of this field increases by one each time the assignment of the 16-bit package_id number is completed once. It becomes a unique package identifier together 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. If 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: 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: An index of the prefix of the homepage URL of the program item corresponding to this package. This field has a value that specifies one of the prefixes defined in 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: 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 the minimum information about the current or future package, and if it is “1”, PGT_package_info () contains information about the program item that has already been broadcast. If it contains only “replay” information and is “2”, PGT_package_info () contains all information about the program that is currently or after broadcast. “Replay” is a service that allows program items that have already been broadcast to be downloaded or streamed for free from an Internet server for viewing.

PGT_logical_channel_index: An 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 a “replay” URL exists for this package.

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

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

  package_protection_type: indicates the encryption form applied to this package. If this value is “0”, it is unencrypted; if it is “1”, all assets in this package are encrypted; if it is “2”, it is in this package. Indicates that only some of the assets or some of the assets have been encrypted, and the 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 only the first 10 minutes of the video asset and the audio asset are encrypted.

  pay_type: This field is meaningless if the package_protection_type is "0" and is ignored by the receiver, and has a meaning if it is "1" or "2". If the value of this field is "0", it indicates "pay subscription required", and if it is "1", it indicates "pay-per-view". The relevant payment guide information must 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 is present 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 globally unique content identifier is included for the program item corresponding to this package.

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

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

live_flag: If the value of this flag is "1", it 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 a “rebroadcast” of a program item that has already been broadcast.

rebroadcast_exist_flag: When the value of this flag is “1”, it indicates that there is a “rebroadcast” plan for the program item corresponding to this package.
recording_flag: When the value of this flag is “1”, it 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: When the value of this flag is “1”, it indicates that there is “screen commentary broadcast” for this package.
sign_language_flag: If the value of this flag is “1”, it indicates that “sign language broadcasting” is available for this package.
subtitles_flag: When the value of this flag is “1”, it indicates that there is “subtitle broadcasting” for this package. Subtitles are based on UTF-8 encoding.

  multivew_flag: When the value of this flag is “1”, it indicates that the entire package is “multi-view broadcast” or that this package partially includes “multi-view broadcast”. The “multi-view broadcast” includes all types of binocular stereoscopic broadcast, multi-view 3D broadcast, multi-view broadcast, and the like.

  picture_size_grade_count: The number of ranks of the screen size. If 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: Rank of screen size. For example, if the value of this field is “0”, the pixel resolution is 240 pixels, “1” is 480 pixels, “2” is 720 pixels, and “3”, based on the horizontal resolution. In some cases, 1,280 pixel class, “4” indicates 1,920 pixel class, “5” indicates 3,840 pixel class, and “6” indicates 7,680 pixel class. A picture_size_grade of two or more 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 audio.
audio_grade: Indicates the type of audio. For example, if the value of this field is "0", it indicates that the audio is mono, if "1", it indicates that the audio is stereo, and if "2", the audio is 5. It indicates that the audio is one-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 ISO639 language identifier for additional audio in a language different from the main audio.
additional_audio_grade: Indicates an additional other language audio type. For example, if the value of this field is "0", it indicates that the audio is mono, if "1", it indicates that the audio is stereo, and if "2", the audio is 5. It indicates that the audio is one-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 the appropriate registrar.
content_id: Content identifier of the program item corresponding to this package. This identifier is managed by each author. One set of content_originator_id and content_id is a content identifier unique to the world.

content_major_version: The major version of the program item corresponding to this package.
content_minor_version: Index of the sub-version of the program item corresponding to this package.
genre_system_id: Identifier of a system that classifies genres Actually, it corresponds to sub_table_id of the genre table.

major_genre: Index of major genre of 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: Index of the sub-genre of the program item corresponding to this package. This index is an index for the entry of the sub-genre in major_genre in the genre table. For example, the sub-genre includes soccer among sports.

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

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

sequel_package_id: The package_id of the immediately 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 one of the series in the season.
rebroadcast_package_id: An identifier of a package corresponding to “rebroadcast” for this package.

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

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

  multiview_scheme_type: If the value of this field is “1”, it indicates that the method of “multi-view broadcast” is binocular stereoscopic, and if “2”, the method of “multi-view broadcast” is multiple. View point 3D, "3" indicates that the system of "multi-viewpoint broadcast" is an inward-type multi-viewpoint, and "4" indicates that the system of "multi-viewpoint broadcast". , Indicates outward multi-view, and “5” indicates that the method of “multi-view broadcast” is multi-view in various directions.

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

  As shown in Table 12, the syntax of PGT_associated_sub_table () conforms to the syntax of a general MMT table. The meaning of each syntax element is defined below.

table_id: identifier indicating the type of this table.
version_id: identifier indicating the configuration of this table. When the structure of this table is modified by the standard revision, the value of this field changes. The receiver determines, based on this value, whether the table has been configured so that it can understand the contents of the table itself. This value is incremented only when the contents of the table are incompatible with the existing one.

table_sub_id: Subtable identifier.
update_version: A version number indicating a change in content from the field following this field to the last byte of this subtable. 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 therein is different from the value, the receiver reads and decodes this sub-table again.

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

  PGT_package_info_module () is used to provide a guide for one or more packages when the PGT does not directly include the package guide information but indirectly includes the package guide information by referring to an external path or file where the package guide information exists. Data structure.

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: identifier of PGT_package_info_module (). 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 one, regardless of whether the identifier can be reused, and reset to 0 at the maximum value of 255.
PGT_package_info_module_length: The number of bytes from the next of this field to the last byte of PGT_package_info ().
reallocation_flag: If the value of this field is “1”, information about a package different from the package included in the previously received module having the same identifier as that of this module is included in this module. Indicates that That is, it indicates that the identifier is reused.
PGT_package_count_in_this_module: Number of package information included in this module.
CRC_32: The same field as CRC_32 defined by the section syntax of the MPEG-2 system standard.

  An AAT (Adjunct Asset Table) transmits information about an auxiliary asset (adjunct asset). The AAT is periodically transmitted as a separate asset constituting a package to which a primary asset corresponding to an object to be synchronized with the auxiliary asset included in the AAT belongs.

  The method of synchronizing the primary asset and the auxiliary 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: identifier indicating the type of table. A unique value corresponding to AAT is assigned.
version_id: identifier indicating the configuration of AAT. When the structure of the table is modified by 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 a number of sub-tables and transmitted, each sub-table is identified.

update_version: Since the AAT is transmitted periodically, if the content of the AAT is different from the content of the AAT having the same sub_table_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 and decrypts the AAT content again.
table_length: 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: The number of the next locator_prefix. The locator_prefix is concatenated with the end of the locator text string provided by adjunct_asset_locator to form a URL. The adjunct_asset_locator refers to the locator_prefix using the order of appearance of the locator_prefix as an index. The value OxFF of this field is not used. Therefore, a maximum of 255 locator_prefixes can be included.

locator_prefix_length: Length of locator_prefix text column.
locator_prefix_byte: The byte of the locator_prefix text string. It does not include the last null byte of the text string.
adjunct_asset_type: type of auxiliary asset. Assign unique values to each type, for example, web documents, widgets, interactive applications, audio clips, video clips, graphics, text, images, auxiliary media components, and the like. This adjuct_asset_type value applies analogously to the auxiliary asset 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. If the number of auxiliary assets having the same adjuct_asset_type exceeds 256, the description is made using two or more syntax loops.

  adjunct_asset_id: 48-bit globally unique identifier that identifies the auxiliary asset. Here, the uniqueness is maintained only for a certain period, and after a certain period, the identifier can be reused. To be 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 specifies a registrar and is registered for each provider, and the asset identifier is managed by the provider itself.

execution_attribute: contains various fields that indicate how to execute when the receiver receives the auxiliary asset.
execution_on_reception: A flag indicating whether or not “immediate execution” is performed after storing the received auxiliary asset in the auxiliary asset cache inside the receiver. If not executed immediately, it may be executed at a designated time 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: Flag indicating whether or not the auxiliary asset is media_service_bound. If 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 directly executed. When the value of this flag is “0”, the auxiliary asset is indirectly implemented by another auxiliary asset.

  visible_to_user: whether the user can make a selection by utilizing the auxiliary asset navigation function, or when another auxiliary asset searches the auxiliary asset list via an API (Application Programming Interface) provided by the receiver. , A 2-bit field indicating whether to make 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 indicating the execution priority of the auxiliary asset. 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 currently executing auxiliary asset is temporarily stopped or terminated from the lowest priority.

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

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

  Adjunct_asset_locator, which is resource data location information, indicates where to read auxiliary assets. The 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 appearing adjunct_asset_locator. 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 the case of the carousel differs depending on the carousel method described in ISO / IEC13818-6: 1998. Therefore, specific items are not included in Table 17.

  locator_type: An 8-bit field indicating whether the location where the auxiliary asset is to be read is the carousel of the Internet or the broadcasting network, the location is the carousel, and what kind of carousel is used when various types of carousels are used together. .

locator_prefix_index: an index designating one of the locator_prefixes in Table 14. If the value of this field is “OxFF”, it indicates that there is no locator_prefix.
directory_path_length: Length of the next directory path. It does not include the last null byte of the text string. If the value of this field is "0", no directory path is used.

directory_path_byte: Directory path byte. It does not include the last null byte of the text string.
entry_path_length: Length of the path following the first page file. It does not include the last null byte of the text string. Only meaningful for auxiliary assets composed of multiple files, such as web pages. If the auxiliary asset is a single file, the value of this field is "0".

entry_path_byte: The byte of the path coming after the first page file. It does not include the last null byte of the text string.
object_count: Number of the next file path. If the value of this field is "0", the entire directory is specified.
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. It does not include the last null byte of the text string.

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

  PGT_reference_descriptor transmits the PGT version and location reference information. It may be included in the SMT_M_descriptor syntax loop or in the SMT_S_descriptor syntax loop (SMT_S_descriptor is used for the descriptor in the PPT_body () syntax element group included in SMT-S). If PMT_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 the 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: The number of bytes from the next of this field to the last byte of this descriptor.
PGT_provider_id: A unique identifier of an institution that provides PGT. One institution can provide one PGT, and PGT_provider_id is assigned via the registrar.

PGT_update_version: A version number indicating whether or not the PGT content is changed. When the PGT content is updated, this value is incremented by one. After the maximum value 255, it is reset to zero. If the version number of the PGT stored therein 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 updated 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 attempts to access in the order of the list of MMT_general_location_info ().

  MMT_composition_descriptor provides spatial screen layout 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 a SMT_S_descriptor syntax loop or a PPT_descriptor syntax loop (PPT_descriptor is used for the descriptor in the 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: The number of bytes from the next of 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 reset to 0 after the maximum value 255.
compression_type: The compression method of the package composition information. If the value of this field is "0", it indicates that the package composition is not compressed, and if it is "1", it indicates that the package composition has been compressed by GZIP. Other values are reserved for later use.
XML_length: Length of byte of package composition information.
XML_package_composition_byte: Byte of package composition information. The definition of the package composition information is described in ISO / IEC JTC1 / SC29 / WG11m19266.

  The alternate_package_descriptor is used for viewing the live broadcast interrupted by the regular schedule, when the viewer uses the alternative package to continuously view the live broadcast, or when the live broadcast of only the latter half of the entire event (for example, the live golf) is performed. This is a descriptor that allows the user to view the event from the beginning using an alternative package. Also, the alternate_package_descriptor may be used as a substitute package for an entire package (that is, from the start to the end) irrespective of whether or not the live broadcast is possible.

  The MMT_package_descriptor may be included in the SMT_S_descriptor syntax loop or the PPT_descriptor syntax loop. If the location of the substitute package is a large number of places, 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 the present specification, for convenience of description, the syntax of alternate_package_descriptor is shown in Table 20, and the meaning of each field is defined below it.

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

reserved: As a field reserved for later use, its value is filled with 0x7F.
just_alternate_flag: Indicates that the content included in this descriptor is for an alternative package of the package containing this descriptor (regardless of whether it is for live broadcast or not). If the value of this flag is “1”, future_flag has no meaning, and text_length is always “0”.

  future_flag: 1-bit field indicating whether the content included in this descriptor is for an alternative program to be viewed in advance or for an alternative program to be viewed continuously 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 viewed subsequently after the end.

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

MMT_general_location_info (): General location reference information defined by MMT, and its contents 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: Byte constituting a text string describing the alternative program. This field does not include a trailing null byte.

  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 the 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.

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

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

  language_descriptor is used to specify the language of the asset for which the language to be used needs to be specified. For example, it is necessary to clearly indicate in which language an asset corresponding to audio, subtitles, screen commentary broadcasting, and the like was created. The language_descriptor may be included in the PPT_descriptor syntax loop or asset_descriptor syntax loop of PPT, and in the SMT_S_descriptor syntax loop or asset_descriptor syntax loop in SMT-S. When this descriptor is included in the PPT_descriptor or SMT_S_descriptor syntax loop, the language of all assets of 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. Descriptor content that applies to the asset takes precedence over descriptor content that applies 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: The number of bytes from the next of this field to the last byte of this descriptor.
ISO_639_language_code: 3-byte language identifier according to the ISO 639 standard.

  clock_reference_descriptor is used to notify the receiver of the relationship between the encoder clock for media synchronization and the MMT system clock. MMT uses NTC (Network Time Protocol) UTC as a system clock, and allows an asset encoder clock 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 transmitted periodically with a period 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: The number of bytes from the next of this field to the last byte of this descriptor.

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

FIG. 5 shows an S1 signaling structure according to one embodiment of the present invention.
A summary of six S1 layer messages according to another embodiment of the present invention is as follows.

(1) Message on Information on Tables and Notice (ITN):
Such messages convey the ITN table and other tables that can additionally be used for fast access to the package. The role of the ITN is similar to MPEG-2 PAT, but has other MMT specific functions. The ITN table contains full information about all other S1 tables. In addition, the ITN has information on receiving the notification. 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 CIs but also hierarchical CIs.

(3) Message about Clock Reference Descriptors (CRD):
Such messages carry 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 to protect 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). A perfect or Tier-0 MPT corresponds to an MMT package. This includes the global unique identifier of the package, the location of the MMT composition information (MCI), and a complete or partial (possibly layered MPT if possible) list of MMT assets belonging to the MMT package. including. This also includes package type, package name, package short description, parental rate, audio language, text language, target user profile, required device capabilities, recording permissions and fast play permissions. 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:
Such a message carries a device capability information table (DCIT). Device capability information provides device capabilities for requests and / or recommendations 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 the S1 layer message, table, and descriptor according to another embodiment of the present invention will be defined with reference to FIG.

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

The ITN message, that is, the message including the ITN table, may further include one or more MMT package tables (MPTs) corresponding to the MMT package. The MPT is a globally unique identifier for the package, the location of the MMT composition information (MCI), and a complete or partial (possibly layered MPT if possible) list of MMT assets belonging to the MMT package. including. MPT also includes information such as package type, package name, package short description, parental rate, audio language, text language, target user profile, required device capabilities, recording permissions and fast play permissions. Including package policies.
If the ITN message contains only one MPT, the media delivery service provides only one package to the user at any fixed time instant. If the ITN table includes multiple MPTs with any overlap in time series, the media delivery service will provide multiple packages to the user at any fixed time instant. If the ITN table has no 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.

  The S layer message with MessageID = 0x00 should include the ITN table. Further, the payload_id of the asset path in the IP application data flow transmitting the S layer message having the MessageID = 0x00 is fixed to “0x0000”. The receiver should read and decrypt the ITN message before reading any other messages.

  ITN messages are typically transmitted periodically in a very short period, for example 500 ms, in a broadcast environment to guarantee short power-up delays or low zapping times.

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 of no loop count can be derived from the length of the table. The same rules apply here to other tables.

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: Version of the S layer message. The MMT client may determine whether the received S-layer message is new. In particular, this field is useful when an S-layer message is repeatedly transmitted over a broadcast network. The length of this field is 8 bits.

  length: 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 the ITN message. The unit of retransmission_period is 10 ms.
number_of_tables: Number of tables included in this ITN message.
table_id: 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: version of the table included in this ITN message. This is a copy of the version field in the table included 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 included in the payload of this ITN message. The actual length of the table is table_length + 4.
table (): S hierarchical 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 the ITN table is defined in Table 24, and the meaning of the syntax elements is provided below Table 24.

table_id: table identifier of the ITN table.
version: ITN table version. The newer version overrides 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 method of receiving the notification. 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 transmitted via the interaction channel. An IP address and an IP port number are provided for transmitting the IP broadcast. For delivery over the interaction channel, a URL is provided where the client can poll for notifications over 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 for notifications, it is expected that the client or receiver will poll the notification URL, poll_URL, all poll_period second.
number_of_tables: Number of information tables for which information is provided in this ITN table.
information_table_id: identifier of an information table for which information is provided in this ITN table. The ITN table_id never appears here.
information_table_version: The 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 a physical channel. The value "0" has a special use and is not used as an identifier. If the value of this field is "0", the information table is channel independent, that is, the information table has service-wide information.

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

MMT_general_location_info () for second_location: Alternative address from which the client obtains the information table. Only 0x0F to 0x13 are allowed.
number_of_table_filter_codes: Table filter code numbers for the information table.
language_for_all_table_filter_codes: languages of all immediately following table_filter_codes. 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 following 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 the immediately following table_filter_code. 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: If the value of this flag is "1", a private extension exists.
private_extension (): A group of syntax elements 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 element 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 within 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 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: identifier of a broadcast network transmitting the MPEG-2 TS.
MPEG_2_transport_stream_id: MPEG-2 TS identifier.
MPEG_2_PID: PID of MPEG-2 TS packet.
prefix_index: Index for the prefix defined before this syntax element group. If the value of this field is OxFF, no prefix is used.

URL_length: Length of the URL in bytes. The final null (0x00) must not be counted.
URL_byte: byte data in a 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 IP application data flow.

1.2 Message for MMT Composition Information (CI) MMT Composition Information (CI) is carried by CI messages for out-of-band signaling. The CI message can carry a perfect CI or a hierarchical CI. When a layered CI is transmitted, it is most recommended to transmit a layer-0 CI by using an ITN message in order to reduce the time required for package consumption in a broadcast scenario. When the layer-0 CI is transmitted in the ITN message as reference numeral 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 used, the layer-N CI (where N is not 0) is generally transmitted in a CI message having a changed repetition period and a different message identifier.

1.2.1 CI Message Syntax and Semantics The syntax of the CI message is defined in Table 27, and the meanings of the syntax elements are 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 a CI in a separate CI layer for a separate package.
version: Version of the S layer message. The MMT client may determine whether the received S-layer message is new. In particular, this field is useful when an S-layer message is repeatedly transmitted over a broadcast network. The length of this field is 8 bits.
length: 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 the syntax elements is provided below in Table 28. The MCI table should only be used for perfect CIs or Tier-0 CIs.

table_id: Table identifier of the MCI table.
version: Version of the MCI table. The newer version overrides the old version as soon as it is 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 a multiple clock reference descriptor.

  When the clock reference descriptor is transmitted in the ITN message, it should be encapsulated in a table structure called 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 the 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: Version of the S layer message. The MMT client may determine whether the received S-layer message is new. In particular, this field is useful when an S-layer message is repeatedly transmitted over a broadcast network. The length of this field is 8 bits.
length: 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 of 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 Syntax and Meaning of CRD Table The syntax of the CRD table 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 CIs or Tier-0 CIs.

table_id: CRD table identifier.
version: Version of the CRD table. The newer version overrides the old version as soon as it is 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 carried in security messages or ITN messages. When security information is transmitted in the ITN message as reference numeral 525, it should be encapsulated before being included in the ITN message.

1.4.1 Security Message Syntax and Semantics The security message syntax is defined in Table 31 and the meaning of the 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: Version of the S layer message. The MMT client may determine whether the received S-layer message is new. In particular, this field is useful when an S-layer message is repeatedly transmitted over a broadcast network. The length of this field is 8 bits.
length: 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 meanings of its syntax elements are provided below Table 32.

table_id: Security table identifier.
version: Security table version. The newer version overrides the old version as soon as it is 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.

1.5 Message About MPT (MMT Package Table) Referring to FIG. 5, the MMT package table (MPT) conveys all information about a single package. The S layer message transmitting the MPT is referred to as an “MPT message”. The MPT may be included in the ITN message with another table as reference numeral 515, or may be transmitted in a separate MPT message.

  For layered transmission of a package having a layered CI, the MPT can be partitioned into multiple layered MPTs. The layer-0 MPT is a basic MPT, and unless layered transmission is used, only the layer-0 MPT is transmitted. In the latter case, the tier-0 MPT is a perfect MPT. MPTs at different layers need to have different table identifiers (table_ids). In this standard, eight different values for MPTtabe-id have been assigned so that up to eight MPT layers can be present. The smaller the value of MPTtable_id, the closer the MPT layer is to the basic MPT.

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

1.5.1 Syntax and Meaning of the MPT Message The syntax of the MPT message is defined in Table 33, and the meaning of the syntax elements is provided below Table 33. The MPT message carries only one complete 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: Version of the S layer message. The MMT client may determine whether the received S-layer message is new. In particular, this field is useful when an S-layer message is repeatedly transmitted over a broadcast network. The length of this field is 8 bits.
length: 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 of NPT transmission of the MPT message.
retransmission_period: Retransmission time of this MPT message. The unit of retransmission_period is 10 ms. When a layered MPT is used, the retransmission_period of the upper layer MPT is generally longer than the retransmission_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 to MPTtable_id. When the layered MPT is used among the eight MPT table_ids, 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 layer MPT.
version: MPT version. The newer version overrides the old version as soon as it is 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: Descriptor syntax loop length. 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. The permissible values are shown in Table 35.

package_name: The 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 language (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: The text language (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) targeting the package.
required_device_capability_profiles: Profiles (multiple profiles) of device capabilities required for package consumption.

  parental_guidance_flag: When the value of this flag is “1”, the receiver is allowed to show content for what is set by the viewer for child protection. Do not provide what will be decoded until it can be 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 the package in the internal storage unit for subsequent use.
fast_play_flag: If the value of this flag is “1”, the receiver causes the viewer to command a fast playback of this package.
clock_reference_flag: If the value of this flag is “0”, no clock_reference_id is provided and by default the MMT system clock is the NTP clock, ie the time base for 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 refer to the clock transmitted by clock_reference_descriptor () as the default time base for all assets in this package. The value 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, the other applies only to asset entries in the syntax loop. The latter takes precedence if both fields are included in the MPT syntax.

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

  protection_scheme_id: This field indicates the protection scheme used for all assets in this package. There are two placeholders for the identifier field of the protection scheme 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. The latter takes precedence if both fields are included in the MPT syntax. 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 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: Asset type. This field is similar to stream_type defined in MPEG-2 PMT, but is an extension thereof.

  asset_id: Asset identifier. In CI, asset_id is used to refer to an asset. The asset_id defined in the CI is globally unique. This field is a short alias for a globally unique asset identifier. Aliasing is performed automatically by mapping the appearance order of assets in the list of assets (LoA) in the CI. When CI layering is used, aliasing occurs within the ordered concatenation of all LoAs from layer O to layer N. In the asset information syntax loop in the MPT, the asset_id alias must be represented 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: The clock reference identifier for the asset. This field is used to refer to 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 on assets expressed in multiples in one 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 locations.
asset_descriptors_length: The number of bytes counted from the next field to the end of the asset descriptor syntax loop.
asset_descriptors_byte: bytes in the asset descriptor.

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

1.6.1 DCIT Message Syntax and Meaning The DCIT message syntax 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: Version of the S layer message. The MMT client may determine whether the received S-layer message is new. In particular, this field is useful when an S-layer message is repeatedly transmitted over a broadcast network. The length of this field is 8 bits.
length: 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 of DCIT message transmission in NPT.
retransmission_period: Retransmission time of this DCIT message. The unit of Retransmission_period is 10 ms. When a layered MPT is used, the retransmission_period of the upper layer MPT is generally longer than the retransmission_period of the MPT layer below the upper layer MPT.
MMT_package_table (): Defined in 1.5.2.
DCIT (): Defined in 1.6.2.

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

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

1.7.1 Language Descriptors Language descriptors are used to identify media assets such as audio, commentary broadcasts, subtitles, and the like. 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, it specifies the language of all assets in the package. When the language descriptor is included in the asset descriptor syntax loop in the MPT, it 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 elements 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 the MMT system clock time. MMT allows different clocks to be used for different assets. The clock used in the asset encoder is specified by clock_reference_id.

clock_reference_descriptors must be transmitted periodically in 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 element 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: identifier of the media clock 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 media clock sampling value used by the asset encoder corresponding to the next MMT_system_clock_time.
MMT_system_clock_time: UTC time value in NTP format corresponding to preceding encoder_clock_sample.

1.7.3 Security Descriptor A 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 transmitted periodically in 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: Security solution type. This represents a solution for access control, digital rights management, downloadable CAS or downloadable DRM.
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 to which the client has been authenticated and authorized.
DRM_server_address: The address of the DRM solution server 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 where the client can download the DDRM SW after authentication and authorization.

  6 and 7 are flowcharts illustrating an operation of receiving multimedia data in a receiver according to an embodiment of the present invention.

  Referring to FIGS. 6 and 7, first, in step 615, the receiver receives the S1 message transmitted on the current channel. The S1 message is a message for managing all functions required for consuming the MMT asset and the MMT item.

  In step 617, the receiver determines based on the message ID whether the found S1 message is an ITN message included in the S1 message. For other messages that are not ITN messages, the receiver determines at step 627 whether other messages have been updated. If it is another updated message, the receiver stores the updated other message and the version information of the updated other message in a memory in 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 the determination in step 617, in the case of an ITN message, in step 619, the receiver determines whether or not the ITN message included in the found S1 message has been updated based on the version information. If so, in step 621, the receiver determines whether at least one table (i) in the ITN message has been updated. If updated, the receiver stores the updated at least one table and its version information in the memory of the receiver in 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 check, in step 631, the receiver determines whether or not the CI layer 0 has been updated.

  When the CI layer 0 has been updated, the receiver sets the CI layer 0 as an integrated CI in step 633. Next, the receiver 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 or not the version of the CI layer i is the same as the version of the CI layer 0. If not, the receiver proceeds to step 641. If they are the same, the receiver matches the CI layer i with the integrated CI in step 637. In step 639, the receiver determines whether or not inspection of all CI layers has been completed. If all tests are completed, the receiver transmits the integrated CI to the CI analyzer in step 641. For example, if the receiver determines in step 639 that it has inspected all CI layers, the receiver proceeds to step 641. On the other hand, if the receiver determines in step 639 that all the CI layers have not been checked, the receiver returns to step 635.

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

  In step 647, the receiver determines whether the version of the MPT layer i is the same as the version of the MPT layer 0. For example, if the layers are not the same, the receiver proceeds to step 653. If so, the receiver matches the MPT layer i with the integrated MPT in step 649. The receiver determines in Step 651 whether or not inspection of all MPT layers has been completed. If all checks have been completed, the receiver uses the asset reference in the integrated MPT to find 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 it has completed all MPT layer checks, it proceeds to step 653. In contrast, if the receiver determines that the test has not been completed, the receiver proceeds to step 647.

FIG. 8 is a block diagram of a transmitting 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 generation unit 803, and a transmission unit 805. Although not shown in the drawings, it is obvious to a person having ordinary skill in the art to provide a control unit capable of controlling the components of the transmitting apparatus 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.
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 two networks having different physical characteristics, that is, 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.
The receiving device may be, for example, a terminal, but is not limited to this.

  Receiving apparatus 900 includes receiving section 901, package analyzing section 903, and decoder / playback section 905. Although not shown in the drawings, it is apparent to a person having ordinary skill in the art that the receiving device or the 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 analyzer 903 analyzes the components of the received package.
The decoder / playback unit 905 decodes and plays the content based on the analyzed components of the package.

  Although not shown in the drawings, data can be recorded, stored, and reproduced according to a package generated according to an 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.) Identification Information), asset list information (Asset list Information), rights management information (Rights Management Information), and transport schedule information (Transport Timeline Information). Can be played. When storing and reproducing via a storage medium, it is possible to store and reproduce more easily by replacing the URL with storage location information (for example, memory address or the like) in the description of the embodiment.

  The various embodiments described above are understood to be illustrative examples of the present invention. All features described in connection with any one of the various embodiments described above may be used alone or in combination with other described features. Of one or more of the other embodiments of the present invention, 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, it is to be understood that the invention may be configured without departing from the spirit and scope of the invention as defined by the appended claims and equivalents thereof. It is evident to those skilled in the art that various modifications can be made in detail.

800 service providing server 801 service data providing unit 803 package generating unit 805 transmitting unit 900 receiving device 901 receiving unit 903 package analyzing unit 905 decoder / playback unit

Claims (3)

A multimedia content transmission device,
A control unit for identifying a control message related to the composition of the multimedia content package;
A transmitting unit that transmits a packet including a header and a payload,
The payload includes the control message,
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 relating to the version of the control message;
Extended information including configuration information related to the table included in the control message payload,
The table is
Including an asset list associated with the package;
Apparatus, wherein the specific information includes information related to a configuration of the package.   The apparatus of claim 1, wherein the table includes a table identifier that identifies the table. The table is
Information relating to the length of the table;
The apparatus of claim 1, comprising: information relating to a version of the table.

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