JP6478381B2 - Receiver and program - Google Patents

Description

  The present invention relates to a receiver and a program. In particular, the present invention relates to a receiver and a program for receiving a broadcast signal.

  In recent years, a technique for executing an application on the receiver side that receives a television broadcast has been researched and developed. In the existing technology, an AIT (Application Information Table) is included in the broadcast signal transmitted from the broadcast station side, the AIT is obtained from the broadcast signal on the receiver side, and the application is applied according to the description in the received AIT. Control the execution of Specifically, for example, the receiver controls the activation of the application by using the MH-simple application location descriptor that is always included in each application in the application information descriptor loop in the AIT.

Non-Patent Document 1 “10.16 Application Information Coding System” (p.54-73) and Non-Patent Document 2 “10.3.2 Table Used for Application Transmission System” include AIT (Application Information Table). And the descriptors in the AIT are described.
Non-Patent Document 1 describes a data carousel transmission system capable of transmitting data such as a file constituting a content of data broadcasting and a file referred to in execution of an application via broadcasting.
Non-Patent Document 2 includes a structure of an MMT (MPEG Media Transport) package table (MP table) that gives information constituting a package such as a list of assets including data (items) to be transmitted and arrangement of assets on a network, and Each descriptor in the MP table is described. Non-Patent Document 2 describes the configuration of a data directory management table that provides a directory structure of a file system that constitutes an application, and each descriptor in the data directory management table. Non-Patent Document 2 describes the configuration of an MPU (Media Processing Unit) in an asset, the configuration of a data asset management table that provides version information for each MPU, and each descriptor in the data asset management table. Yes.

"Data broadcasting coding and transmission systems for digital broadcasting Standards DATA CODING AND TRANSMISSION SPECIFICATION FOR DIGITAL BROADCASTING ARIB STANDARD ARIB STD-B24 5.9", March 18, 2014, Japan Radio Industry Association "Media transport system by MMT in digital broadcasting standard MMT-BASED MEDIA TRANSPORT SCHEME IN DIGITAL BROADCASTING SYSTEMS ARIB STANDARD ARIB STD-B60 1.0 version", July 31, 2014 (Japan Radio Industry Association)

  In the technique described in Non-Patent Document 1, it is possible to specify a file as an entry point in the AIT. In the technique described in Non-Patent Document 2, it is possible to know a set of all files included in an application at that time by referring to a data directory management table received by the receiver. However, on the receiver side, there is a problem that it is impossible to quickly know at what timing the initial display can be performed only by designating the entry point. For example, the receiver knows the location of the file indicated as the entry point and the associated file from the entry point, and actually acquires the file by broadcasting or communication. However, the receiver cannot immediately know which of these files is accumulated to start the initial display on the screen.

  Actually, the application is described in, for example, HTML5, and the receiver often executes a file written in HTML5 with a so-called browser function. Therefore, by parsing data written in HTML5, it is possible to analyze which of the files described in the data directory management table is necessary for initial display. However, since such parsing processing itself takes time, it still takes time for the receiver to specify a set of initial files necessary for starting display on the screen.

  The present invention has been made on the basis of the above problem recognition, identifies an initial file without performing processing such as parsing of an application source file, and displays an application screen at the earliest possible timing. It is an object of the present invention to provide a receiver capable of starting display of the program and a program thereof.

[1] In order to solve the above problems, a receiver according to an aspect of the present invention acquires a broadcast receiving unit that receives a broadcast signal, an application information table acquisition unit that acquires an application information table from the broadcast signal, and Acquires resource data related to the application specified in the application information table, acquires information indicating whether or not the resource data is essential for initial presentation from the file storage unit to be stored and the application information table, and initial A file accumulation detection unit for detecting completion of initial presentation resource accumulation when the accumulation of resource data essential for presentation is completed, an accumulation state notification unit for notifying completion of initial presentation resource accumulation detected by the file accumulation detection unit, and The initial presentation resource from the accumulation state notification unit Upon receipt of the notification of completion of accumulation, an accumulation standby unit that controls to start presentation by the application specified in the application information table, and an application that executes the application in accordance with the presentation start control from the accumulation standby unit And an execution unit.
With this configuration, the file accumulation detection unit acquires information indicating whether the resource data is essential for initial presentation from the application information table. Further, the file accumulation detection unit detects whether or not the accumulation of the resources essential for the initial presentation has been completed based on the information indicating whether the resource data is essential for the initial presentation. Then, the accumulation state notification unit notifies the accumulation standby unit that the accumulation of the resources essential for the initial presentation has been completed. When the storage standby unit receives a notification to that effect, it starts presentation by the application. Therefore, the receiver does not need to analyze the resource data itself to determine whether or not the resource is an essential resource for the initial presentation.

  [2] Further, according to one aspect of the present invention, in the above receiver, the file accumulation detection unit is resource data essential for initial presentation from an application initial directory descriptor included in a descriptor area of the application information table. Information indicating whether or not there is in the directory unit, or information indicating whether or not the resource data is indispensable for initial presentation from the application initial resource descriptor included in the descriptor area of the application information table Acquired in units

  [3] Further, according to one aspect of the present invention, in the receiver, the accumulation standby unit registers a listener for waiting for the resource data, and the accumulation state notification unit is configured to register the registered listener. The completion of the initial presentation resource accumulation is notified via.

  [4] Further, according to one aspect of the present invention, an application information table acquisition unit that acquires an application information table from a broadcast signal received by a broadcast signal reception unit, and resource data related to an application specified in the acquired application information table is acquired. In addition, information indicating whether or not the resource data is indispensable for initial presentation is obtained for each resource data from the file storage means to be accumulated and the application information table, and the accumulation of the resource data essential for initial presentation is completed. File storage detection means for detecting completion of initial presentation resource accumulation, storage status notification means for notifying completion of initial presentation resource detection detected by the file storage detection means, and completion of initial presentation resource storage from the storage status notification means Through A storage standby unit that controls to start presentation by the application specified in the application information table, and an application execution unit that executes the application according to the control of the presentation start from the storage standby unit Is a program for making

  According to the present invention, the receiver can grasp the resources essential for the initial presentation without analyzing the source code of the application.

It is a block diagram which shows schematic function structure of the receiver by embodiment of this invention. It is a block diagram which shows schematic structure of the whole television system containing the receiver by the embodiment. It is the schematic which shows the data structure of the application information table used in the embodiment. It is the schematic which shows the data structure of the application initial directory descriptor arrange | positioned at the descriptor area | region of said application information table. It is the schematic which shows the data structure of an application initial resource descriptor arrange | positioned at the descriptor area | region of said application information table. It is a schematic block diagram which shows the structure of the IP data flow which the receiver by the same embodiment receives. It is the schematic which shows the interface of the event listener which the receiver by the embodiment uses, a related definition, etc. It is the schematic which shows the specification of the function addDataResourceEventListener which the receiver by the embodiment uses. It is the schematic which shows the specification of the function removeDataResourceEventListener which the receiver by the embodiment uses. It is the schematic which shows the specification of the data type MMTDataResourceEventType which the receiver by the embodiment uses. It is the schematic which shows the specification of the function DataResourceEventListener which the receiver by the embodiment uses. It is a flowchart which shows the flow of a process in the receiver 1 from the monitoring start of the resource (file or directory) by the receiver by the embodiment to the end of monitoring.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a block diagram showing a schematic functional configuration of a receiver according to the present embodiment. The receiver 1 shown in FIG. 1 has a function of receiving a television broadcast signal and presenting a television broadcast content including video and audio to a viewer, and may be referred to as an application (hereinafter referred to as an “app”). ). As shown in the figure, the receiver 1 includes a broadcast reception unit 11, a broadcast signal analysis unit 12, an AIT acquisition unit 13 (application information table acquisition unit), a communication transmission / reception unit 14, and an application execution control unit 15. The application execution unit 17 (application execution unit), the file system 21 (file storage unit), the file storage detection unit 22, the storage state notification unit 23, and the storage standby unit 24 are configured.

  The broadcast receiving unit 11 receives a broadcast signal. A broadcast signal propagates in the air as a radio wave or propagates through a cable for cable television. The broadcast signal received by the broadcast receiving unit 11 includes a video signal, an audio signal, a data broadcast signal, a control information signal, and the like. As part of the control information, an AIT (Application Information Table), a data directory management table, a data asset management table, an MP table, and the like are included.

The broadcast signal analysis unit 12 analyzes the broadcast signal received by the broadcast reception unit 11, extracts necessary data such as video, audio, and control information, and writes the data as a file in the file system 21. As an example, the broadcast signal is transmitted in a form including an IP data flow. An internal configuration example of the IP data flow will be described later with reference to another drawing.
The broadcast signal analysis unit 12 passes AIT among the data extracted from the IP data flow to the AIT acquisition unit 13. Also, the broadcast signal analysis unit 12 extracts data assets and extracts items from the data assets. The item includes resources necessary for executing the application. Some of the resources are entry point resources that serve as entry points for the application. Also, some of the resources are resources that are essential for initial presentation regarding the application.

  The AIT acquisition unit 13 acquires an AIT obtained from the broadcast signal analyzed by the broadcast signal analysis unit 12. Moreover, the AIT acquisition part 13 extracts various information from the acquired AIT as needed. The information extracted by the AIT acquisition unit 13 includes various descriptors. Further, the descriptor extracted by the AIT acquisition unit 13 includes one or both of an application initial directory descriptor and an application initial resource descriptor. The application initial directory descriptor and the application initial resource descriptor may be collectively referred to as “application initial presentation descriptor”. Further, the AIT acquisition unit 13 instructs the broadcast signal analysis unit 12 and the communication transmission / reception unit 14 to acquire resources necessary for executing the application based on information in the AIT. The internal configuration of the AIT will be described in detail later with reference to another drawing.

  The communication transmitter / receiver 14 performs data communication with an external device via a communication network. The communication transmitter / receiver 14 exchanges data with an external device using, for example, IP (Internet Protocol). When app resource data is distributed from an external server device or the like by communication, the communication transmitting / receiving unit 14 writes the app resource data received by communication as a file in the file system 21.

  The application execution control unit 15 controls the application execution in the application execution unit 17 in accordance with the AIT acquired by the AIT acquisition unit 13. An example of control by the application execution control unit 15 is, for example, application life cycle management. In other words, the application execution control unit 15 performs control such as starting, sleeping, or ending the application. The application execution control unit 15 also performs execution control according to whether or not the application is bound to a specific service (service-bound).

The application execution unit 17 is an execution environment having a function of executing the application acquired by the receiver 1 in accordance with the control information described in the AIT. The application execution unit 17 presents, for example, a hypertext described in HTML5, or executes a program code embedded in HTML data (for example, a code written in JavaScript (registered trademark)). Can do. The application execution unit 17 is realized using, for example, a so-called web browser technology.
The application execution unit 17 executes the application according to the presentation start control from the storage standby unit 24. The application execution unit 17 can start the initial presentation at the stage where the resources essential for the initial presentation can be accumulated in the file system 21 by the configuration and procedure described later. Here, presentation means displaying an image or video on a screen or outputting sound from a speaker or the like. The initial presentation is an initial minimum necessary presentation when the application is executed. Even if not all resources (files) for executing (presenting) the application are available, initial presentation may be possible if only some of them are available. In this embodiment, as will be described later, whether or not a resource is necessary for initial presentation can be read from information in the AIT.

  The file system 21 acquires and accumulates resource data related to the application specified in the AIT acquired by the AIT acquisition unit 13. The file system 21 has both a function for storing a file itself and a function for managing a file in a directory having a tree structure. The file system 21 provides services such as file generation, file writing (accumulation), and file reading through an interface provided to other functions in the receiver 1 (for example, realized as a program running on a computer). provide.

The file accumulation detection unit 22 acquires information indicating whether or not the resource data is indispensable for the initial presentation from the AIT, and completes the initial presentation resource accumulation when the accumulation of the resource data essential for the initial presentation is completed. Detect.
Specifically, the file accumulation detection unit 22 acquires information indicating whether or not the resource data is indispensable for initial presentation from the application initial directory descriptor included in the descriptor area of the AIT for each directory. Alternatively, the file accumulation detection unit 22 acquires, in resource data units, information indicating whether the resource data is essential for initial presentation from the application initial resource descriptor included in the descriptor area of the AIT.

The accumulation state notification unit 23 notifies the accumulation standby unit 24 of the completion of initial presentation resource accumulation detected by the file accumulation detection unit 22.
Specifically, the storage state notification unit 23 notifies the storage standby unit 24 of the completion of initial resource storage via the listener registered by the storage standby unit 24. The listener function for waiting for an event will be described later.

When the storage standby unit 24 receives a notification of the completion of initial presentation resource storage from the storage state notification unit 23, the storage standby unit 24 controls to start presentation by the application specified by the AIT.
Specifically, the storage standby unit 24 registers a listener for waiting for resource data, and receives the notification of completion of initial presentation resource storage from the storage state notification unit 23 via the listener.

The outline of the operation of the receiver 1 having the above configuration is as follows. That is, in the receiver 1, first, the broadcast receiving unit 11 receives a broadcast signal. Then, the broadcast signal analysis unit 12 analyzes the broadcast signal, and the AIT acquisition unit 13 acquires the AIT extracted from the broadcast signal. The AIT includes application entry point (location) information and resource information necessary for executing the application for each application. In addition, the definition in the AIT distinguishes whether an application is associated with a specific broadcast service (such as a channel) or independent from the service. Further, based on the life cycle control code in the AIT, the receiver 1 controls the activation and termination of the application. Further, according to the description in the AIT, the receiver 1 acquires resources necessary for executing the application. The resource may be extracted from a broadcast signal or acquired from an external server device or the like by communication (for example, communication via the Internet). In acquiring these resources, the file accumulation detection unit 22 reads information on descriptors in the AIT in advance. Thereby, it is grasped whether the resource is essential for the initial presentation in units of directories or in units of resource data (files). Further, when an application is activated under the control of the application execution control unit 15, the storage standby unit 24 registers a listener for event standby. This listener is used to notify the storage standby unit 24 of a state detected by the file storage detection unit 22 (a state indicating whether or not storage has been completed).
When the application uses JavaScript (registered trademark), the storage standby unit 24 controls whether to start execution of the application based on the received notification. That is, in a state where all the resources necessary for the initial presentation have been accumulated in the file system 21, the storage standby unit 24 permits the initial presentation by the application to be started.
When the application does not use JavaScript (registered trademark) and is described only in HTML5, the application execution control unit 15 knows the resources necessary for the initial presentation, and the file accumulation detection unit 22 determines what these files are. Tell them. When all of these files are accumulated in the file system 21, the file accumulation detection unit 22 completes accumulation in the application execution control unit 15 via a notification means from the accumulation state notification unit 23 to the accumulation standby unit 24. And the application execution control unit 15 notifies the application execution unit 17 that presentation is possible. Then, the application execution unit 17 reads the resource from the file system 21 and presents it.
As a result, the initial presentation can be started after the resources necessary for the initial presentation are always available. Further, the application execution unit 17 does not need to parse and analyze an application source (for example, a code described in HTML5) in order to distinguish resources that are essential for initial presentation.

  FIG. 2 is a configuration diagram showing a schematic configuration of a television system including the receiver 1 described above. As illustrated, the television system 100 includes a transmission device 3, a server device 5, and a receiver 1.

  The transmission device 3 transmits a broadcast signal. The broadcast signal transmitted by the transmission device 3 includes video data, audio data, data broadcast data, control information data, and the like. The AIT described above is included as part of the control information data in the signal transmitted by the transmission device 3. The broadcast signal transmitted by the transmitter 3 is transmitted by radio (terrestrial wave or satellite broadcast wave) or wired (television broadcast cable).

  In response to a request from the receiver 1, the server device 5 provides data such as an application program code. The server device 5 is connected to the receiver 1 via a communication network (for example, the Internet), and can receive data from the receiver 1 and transmit data to the receiver 1. . The server device 5 is realized using, for example, a computer.

  The receiver 1 receives a broadcast signal from the transmission device 3 and performs communication with the server device 5. The receiver 1 receives an application program from the transmission device 3 or the server device 5 in accordance with the AIT included in the broadcast signal from the transmission device 3. The receiver 1 controls the execution of the application according to the received application control code in the AIT. That is, the receiver 1 performs control such that the application can be activated, activated, or terminated according to the received application control code in the AIT.

Next, the configuration of the AIT used in this embodiment will be described.
FIG. 3 is a schematic diagram showing the data structure of the AIT. This figure shows the data structure, the number of bits of each data item included in the data structure, and the data notation. In the figure, the data structure is expressed in a formal language having a block structure. Note that “uimsbf” in the data notation represents “unsigned integer, most significant bit first”, that is, an unsigned integer and the most significant bit is first. “Bslbf” represents “bit string, left bit first”, that is, a bit string and the left bit is the head. “Rpchof” represents “remainder polynomial coefficients, highest order first”, that is, the remainder of the polynomial coefficients and the highest rank.

  As illustrated, the AIT includes a first descriptor area and a second descriptor area. In the first descriptor area, N (i = 0, 1,..., N−1) descriptors “descriptor ()” are repeated as indicated by the “for” clause. In the second descriptor area, as indicated by the “for” clause, M descriptors “descriptor ()” (j = 0, 1,..., M−1) are repeated. In the present embodiment, an application initial directory descriptor “Application_Initial_Directory_Descriptor ()” or an application initial resource descriptor “Application_Initial_Resource_Descriptor ()” is provided in the second descriptor area in the AIT.

There is only one first descriptor area in one AIT. In the first descriptor area, a common descriptor common to a plurality of applications is provided.
There is one second descriptor area corresponding to each application in the application loop in the AIT. The second descriptor area is provided with an application descriptor for the application. Since the application initial presentation descriptor is provided in the second descriptor area, information for specifying the entry point resource and the initial resource is described for each application. In other words, the receiver 1 acquires an AIT and identifies an entry point resource and an initial resource with reference to the application initial presentation descriptor for each application included in the application loop of the AIT. For example, when the application initial directory descriptor is included in the AIT, the receiver 1 refers to the application initial directory descriptor, and based on the directory identification information for identifying the initial directory, the entry point stored in the initial directory. Identify resources and initial resources. Further, for example, when the application initial resource descriptor is included in the AIT, the receiver 1 refers to the application initial resource descriptor and based on the resource identification information for identifying the entry point resource or the initial resource, the entry point Identify resources and initial resources.

  In other words, the AIT acquisition unit 13 specifies the entry point resource and the initial resource by referring to the application initial presentation descriptor for each application. Then, the AIT acquisition unit 13 acquires the specified entry point resource and initial resource via the communication transmission / reception unit 14 or the broadcast signal analysis unit 12.

Hereinafter, a portion of the AIT other than the first descriptor area and the second descriptor area will be described.
(1) section_syntax_indicator (section syntax instruction)
This section syntax instruction is a 1-bit field, and its value is always “1”.
(2) section_length (section length)
This is a 12-bit field indicating the number of bytes of the section from the section length field to the end of the section including CRC32. In order to prevent the length of all sections from exceeding 4096, the section length value shall not exceed 4093 ("0xEFD" in hexadecimal).
(3) application_type (application format)
This is a 16-bit field indicating the format of the application to be controlled by the AIT.
The application format values and their meanings are as follows: That is, the value “0x0000” is reserved for future use. A value “0x0001” indicates an ARIB-J application. Values “0x0002” through “0x000F” are reserved for future use. A value “0x0010” indicates a broadcast / communication cooperation HTML5 application. The value “0x0011” is reserved for future use. Values “0x0012” through “0x7FFF” are reserved for future use.

(4) version_number (version number)
This is a 5-bit field and the version number of the subtable. The version number is incremented by 1 when there is a change in the information in the subtable. If the value becomes 31 (binary number “11111”), then it returns to 0.
(5) current_next_indicator (current next instruction)
This is a 1-bit field and is always “1”.
(6) section_number (section number)
This is an 8-bit field and represents the section number. The section number of the first section in the sub-table is “0x00”. The section number is incremented by 1 every time a section having the same table identification and application format is added.
(7) last_section_number (last section number)
This is an 8-bit field that defines the number of the last section in the subtable to which the section belongs.
(8) common_descriptors_length (common descriptor loop length)
This 12-bit field defines the byte length of the subsequent common descriptor area. Descriptors in this descriptor area apply to all applications in the AIT subtable.

(9) application_loop_length (application information loop length)
This 12-bit field defines the byte length of the entire loop in which subsequent application information is stored.
(10) application_control_code (application control code)
This is an 8-bit field that defines a control code that controls the state of the application. The semantics of this field are specified for each application format. The following semantics are used when not specified for each application format. That is, when the value of the application control code is “0x01” (identification name: AUTOSTART), this means that the application is activated. When the value is “0x02” (identification name: PRESENT), this indicates that the application is in an executable state. When the value is “0x04” (identification name: KILL), it means that the application is terminated. When the value is “0x05” (identification name: PREFETCH), it means that the application is acquired and held.
(11) application_descriptors_loop_length (application information descriptor loop length)
This is a 12-bit field that defines the byte length of the subsequent descriptor area. Descriptors in this descriptor area apply only to the specified application.
(12) CRC_32 (CRC, cyclic upper code)
This is a cyclic upper code for error detection / correction, and is an ITU-T recommendation H.264. 222.0.

  Next, a data structure of a descriptor for initial presentation of an application will be described with reference to FIGS. 4 and 5. The application initial directory descriptor shown in FIG. 4 is a descriptor for designating a mandatory flag for each directory. On the other hand, the application initial resource descriptor shown in FIG. 5 is a descriptor for designating an essential flag for each resource data (file). The system according to the present embodiment may be implemented so that only one of the application initial directory descriptor and the application initial resource descriptor is used, or both the application initial directory descriptor and the application initial resource descriptor are used. May be implemented to allow

FIG. 4 is a schematic diagram showing the data structure of the application initial directory descriptor used in this embodiment. This application initial directory descriptor is provided in the second descriptor area in the AIT shown in FIG.
Hereinafter, each field in the application initial directory descriptor will be described.
(1) descriptor_tag (descriptor tag)
The descriptor tag identifies each descriptor. The bit length of the descriptor tag depends on the media transport system used. In the present embodiment, the number of bits in the descriptor tag field of the application initial directory descriptor is 16.
(2) descriptor_length (descriptor length)
The descriptor length indicates the number of data bytes that follow this field. That is, the descriptor length field is an area for writing indicating the number of data bytes following this field. The number of bits in the descriptor length field differs depending on the application initial directory descriptor. In the present embodiment, the number of bits in the descriptor length field of the application initial directory descriptor is eight.

(3) initial_directory_number (initial directory number)
The initial number of directories indicates the number of initial directories that store initial resources. That is, the initial number of directories is an area for writing the number of directories for storing entry point resources and initial resources. In the present embodiment, the number of bits in the initial directory number field of the application initial directory descriptor is eight.
(4) node_tag (node tag)
The node tag is information for identifying a node (here, a directory) in the file system. The node tag field in the application initial directory descriptor is an area in which a node tag indicating the initial directory is written. The node tag in the AIT is associated with a node tag in a data directory management table described later. In the present embodiment, the number of bits in the node tag field of the application initial directory descriptor is 16.

(5) required_flag (required flag)
The essential flag indicates whether or not corresponding data is essential for initial presentation. That is, the essential flag is importance level information indicating the importance level of the corresponding data. The mandatory flag field in the application initial directory descriptor is an area for writing whether or not the initial resource stored in the initial directory is mandatory in the initial presentation of the application. The fact that the initial resource is essential in the initial presentation of the application means that the initial resource must be referred to in the application activation process. The initial resource is not essential in the initial presentation of the application, although it is desirable to refer to the initial resource in the application activation process, but it is not necessary to refer to the initial resource. That is, when a certain initial resource is not essential, the receiver 1 can perform initial presentation of the application in a minimum state without referring to the initial resource. The bit length of the essential flag is 1. When the initial resource is essential, the value “1” is written in the mandatory flag field. On the other hand, when the initial resource is not essential, the value “0” is written in the mandatory flag field.

  As described above, the application initial directory descriptor is data including identification information of the initial directory. Thereby, the receiver 1 can specify the initial directory to which the initial resource belongs only by referring to the AIT. As a result, the receiver 1 can directly identify and acquire the initial resource without parsing data accumulated from broadcast waves or the like, so that the processing amount in the initial presentation of the application can be reduced. . In addition, since the AIT generation apparatus can specify initial resources in units of initial directories in which a plurality of initial resources are grouped, the processing can be simplified.

  The application initial directory descriptor is data including an essential flag indicating the importance of the initial resource stored in the initial directory. Thereby, for example, the receiver 1 can preferentially acquire the initial resource with high importance, and can perform the initial presentation of the application when the initial resource with high importance can be acquired. Therefore, the receiver 1 can reduce the time required for the initial presentation of the application. In addition, since the AIT generation apparatus can specify the importance of initial resources in units of initial directories in which a plurality of initial resources are grouped in the specification of initial resources, the processing can be simplified.

FIG. 5 is a schematic diagram showing the data structure of the application initial resource descriptor used in this embodiment. This application initial resource descriptor is provided in the second descriptor area in the AIT shown in FIG.
(1) descriptor_tag (descriptor tag)
The descriptor tag identifies each descriptor. The bit length of the descriptor tag depends on the media transport system used. In this embodiment, the number of bits in the descriptor tag field of the application initial resource descriptor is 16.
(2) descriptor_length (descriptor length)
The descriptor length indicates the number of data bytes that follow this field. That is, the descriptor length field is an area for writing indicating the number of data bytes following this field. The number of bits in the descriptor length field varies depending on the application initial resource descriptor. In the present embodiment, the number of bits in the descriptor length field of the application initial resource descriptor is eight.

(3) initial_resource_number (initial resource number)
The initial resource number indicates the number of initial directories. That is, the initial number of directories is an area for writing the number of directories for storing entry point resources and initial resources. In the present embodiment, the number of bits in the initial resource number field of the application initial resource descriptor is eight.
(4) Item_id (item identification)
Item identification indicates identification information (ID) for identifying an item. That is, the item identification field in the application initial resource descriptor is an area in which the item identification of the item corresponding to the initial resource is written. In the present embodiment, the number of bits in the item identification field of the application initial resource descriptor is 32.

(5) node_tag (node tag)
The node tag is information for identifying a node (here, resource (file)) in the file system. The node tag field in the application initial resource descriptor is an area in which a node tag of an item indicating an entry point resource and an initial resource is written. The node tag in the AIT is associated with a node tag in a data directory management table described later. In the present embodiment, the number of bits in the node tag field of the application initial resource descriptor is 16.

  In the present embodiment, the item identification and the node tag in the application initial resource descriptor both identify the entry point resource or the initial resource. Therefore, either the item identification or the node tag may be omitted in the application initial resource descriptor. When both the item identification and the node tag are included, the receiver 1 acquires entry data and initial resources based on either of them.

(6) required_flag (required flag)
The essential flag indicates whether or not corresponding data is essential for initial presentation. The mandatory flag field in the application initial resource descriptor is an area for writing whether or not the initial resource indicated by the item identification or node tag described above is mandatory in the initial presentation of the application. The fact that the initial resource is essential in the initial presentation of the application means that the initial resource must be referred to in the application activation process. The initial resource is not essential in the initial presentation of the application, although it is desirable to refer to the initial resource in the application activation process, but it is not necessary to refer to the initial resource. That is, when a certain initial resource is not essential, the receiver 1 can perform initial presentation of the application in a minimum state without referring to the initial resource. The bit length of the essential flag is 1. When the initial resource is essential, the value “1” is written in the mandatory flag field. On the other hand, when the initial resource is not essential, the value “0” is written in the mandatory flag field.

  As described above, the application initial resource descriptor is data including identification information of the initial resource. Thereby, the receiver 1 can specify an initial resource only by referring to the AIT. Thereby, the receiver 1 can specify an initial resource directly, without parsing the data accumulate | stored from the broadcast wave etc. Also, the initial resource can be specified without referring to the data directory management table. Thereby, the processing amount in the initial presentation of an application can be reduced. In addition, since the AIT generation device can individually specify a plurality of initial resources in specifying the initial resource, for example, when the directory to which the initial resource belongs includes a resource that is not referenced in the initial presentation of the application. Even if it exists, processing can be simplified. Even in such a case, since the receiver 1 can acquire only the initial resource, the processing amount in the initial presentation of the application can be reduced.

  The application initial directory descriptor is data including a mandatory flag indicating the importance of the initial resource. Thereby, for example, the receiver 1 can preferentially acquire initial resources with high importance, or can perform initial presentation of an application when initial resources with high importance can be acquired. Therefore, the receiver 1 can reduce the time until the initial presentation of the application.

Next, the configuration of data transmitted as a broadcast signal will be described. In this embodiment, MMT (MPEG Media Transport) is used as a technology for transmission.
FIG. 6 is a schematic configuration diagram showing a configuration of an IP data flow transmitted as part of a broadcast signal. As shown in the figure, the package transmitted in the IP data flow includes a data transmission message, an MP table (MMT (MPEG Media Transport) package table), and a data asset. The data transmission message includes a data directory management table and a data asset management table. The IP data flow configuration itself is based on existing technology.

  The data directory management table has a pair of a path name and a node tag for each file. The path name is a combination of the directory node name and the file name in the directory, and is a name for uniquely identifying the file. The node tag is also a value that can identify each entry in the data directory management table, and this node tag is used for association with an entry in the data asset management table.

  The data asset management table is a table for managing data assets. Each entry in the data asset management table has a component tag, an MPU (Media Processing Unit) sequence number, an item ID, and a node tag. Among these, the component tag is information for identifying the asset, and is associated with the component tag in the MP table. The item ID indicates a specific item in the data asset. As described above, the node tag is used to associate with the entry in the data directory management table.

  The MP table is a table having links to asset locations. Each entry in the MP table includes an asset ID, a component tag, and location information. Among these, the asset ID is information for identifying an asset such as a video asset, a data asset, or a data asset. The component tag is a value used for associating with an entry in the data asset management table. The location information indicates a specific location of the data asset. The location information indicates, for example, information on the position of a data asset in an IP data flow of broadcast waves, a data asset acquisition URL (Uniform Resource Locator) managed in an external device, and the like.

  The data asset stores actual asset data. Each data asset includes one or more MPUs. Each MPU is identified by an MPU sequence number in the data asset and includes one or more items.

Next, a function for waiting for the arrival of a resource that is essential for initial presentation when the application is executed in the receiver 1 will be described.
FIG. 7 shows an interface of an event listener used internally by the receiver 1 and related definitions.
In the figure, MMTResoureReference (MMT resource reference) is a data structure representing a path name of a file which is a data resource. This data structure is composed of two strings: a folder path (folder_path) and a file name (filename).
The function addDataResourceEventListener is for registering a listener related to the data resource. This function addDataResourceEventListener is called with two parameters. The first parameter is resource_ref (resource reference), which has the type MMTResoureReference above. The second parameter is a listener and has a type of MMTDataResourceEventListener. The listener is a means for returning the event type and the information of the target resource of the event when the event arrives.
The function removeDataResoureEventListener is for removing the listener.

The function addDataResourceEventListener and the function removeDataResourceEventListener are functions that are called from the storage standby unit 24. The storage standby unit 24 waits for an event related to the specified resource until the listener is deleted after registering the listener using the function addDataResourceEventListener. In addition, the storage standby unit 24 receives a notification regarding the arrived event. This notification is issued from the accumulation state notification unit 23 in response to a change in the state in the file system 21.
MMTDataResourceEventType represents the type of the event. The event types here are “updated”, “stored”, “stored_required”, and “deleted”. “updated” is an event indicating that the update of the target resource is started (including the case where reception is started when the resource originally does not exist). “Stored” is an event indicating that the target resource is accumulated (acquisition completion). Further, “stored_required” is an event indicating that at least resources necessary for initial presentation among the target resources are accumulated (acquisition completion). “Deleted” is an event indicating that the target resource has been deleted from the file system 21.

  FIG. 8 shows the specification of the function addDataResourceEventListener. As shown in the figure, this function addDataResourceEventListener registers an event listener for monitoring completion of data resource update / acquisition. The parameter resource_ref is a reference (path name) of a resource to be monitored. The parameter listener is a function to be called when the monitored resource is updated or acquired.

  FIG. 9 shows the specification of the function removeDataResourceEventListener. As shown in the figure, this function removeDataResourceEventListener removes the event listener registered by the function addDataResourceEventListener. The parameter listener is an event listener to be deleted. If this parameter listener is omitted, it means that all event listeners registered at that time are deleted.

  FIG. 10 shows the specification of the data type MMTDataResourceEventType. “updated” indicates that the listener has been called when the monitored data resource is started to receive or update. “stored” indicates that the listener has been called when the data resource being monitored has been acquired by the receiver. “stored_required” indicates that the listener has been called when the data resource necessary for the initial presentation has been acquired by the receiver. “deleted” indicates that the listener is called because the monitored data resource is deleted from the cache (cache in the file system of the receiver 1).

FIG. 11 shows the specification of the function DataResourceEventListener that is called back when an event occurs. As shown in the figure, the parameter event_type of the function DataResourceEventListener is data representing the type of event, as shown in FIG. The parameter resource_ref is a resource designated as a start target and represents the resource in which the current event has occurred.
The accumulation state notification unit 23 notifies the accumulation standby unit 24 of a change in the state of the resource using the function of this function DataResourceEventListener.

FIG. 12 is a flowchart showing the flow of processing in the receiver 1 from the start of monitoring to the end of monitoring for a specific resource. Hereinafter, it demonstrates along this flowchart. Here, the resource is resource data (file) or a directory for storing resource data.
Step S1: First, the storage standby unit 24 specifies a specific resource and registers a listener.
Step S2: Next, the storage standby unit 24 waits for the arrival of an event for the resource specified by the listener registered in Step S1 above. During this time, the file accumulation detection unit 22 continues to monitor the target resource. Note that while the file accumulation detection unit 22 is monitoring the status of the file in step S2, the accumulation standby unit 24 can also delete the registered listener. When a predetermined state change occurs for the specified resource, or when the storage standby unit 24 issues a function for deleting the listener, the process goes to step S2 and proceeds to the next step.

Step S3: Next, the accumulation state notifying unit 23 analyzes the reason for exiting Step S2. Step S2 is exited when the storage standby unit 24 deletes the listener, or when the file storage detection unit 22 detects a change in the state of the resource being monitored. When the listener is deleted (step S3: YES), the receiver 1 finishes the process of the entire flowchart. When the file accumulation detection unit 22 detects a change in the state of the file (step S3: NO), the process proceeds to the next step S4.
Step S4: When the process proceeds to step S4, the storage state notification unit 23 notifies the storage standby unit 24 of the event that has occurred by calling the function DataResourceEventListener. When the process in step S4 ends, the process returns to step S2 to wait for the next event related to the resource.

Note that when the application uses JavaScript (registered trademark), the storage standby unit 24 controls whether to start execution of the application based on the received notification. That is, in a state where all the resources necessary for the initial presentation have been accumulated in the file system 21, the storage standby unit 24 permits the initial presentation by the application to be started.
When the application does not use JavaScript (registered trademark) and is described only in HTML5, the application execution control unit 15 knows the resources necessary for the initial presentation, and the file accumulation detection unit 22 determines what these files are. Tell them. When all of these files are accumulated in the file system 21, the file accumulation detection unit 22 completes accumulation in the application execution control unit 15 via a notification means from the accumulation state notification unit 23 to the accumulation standby unit 24. And the application execution control unit 15 notifies the application execution unit 17 that presentation is possible. Then, the application execution unit 17 reads the resource from the file system 21 and presents it.

Here, there will be described a plurality of cases regarding the meaning of the events “stored” and “stored_required” described above.
(A) When registering a listener by specifying a resource As described above, the function addDataResourceEventListener is called by specifying resource_ref as a parameter. The resource specified as a parameter here can be a directory or a single file.
(A-1) When the specified resource is a directory When the specified resource is a directory, the directory is defined as “required for initial presentation” in the application initial directory descriptor. If the storage status notification unit 23 detects that all files in the directory have been stored, the storage state notification unit 23 notifies the storage standby unit 24 of the storage completion ("stored") of the directory.
If the specified resource is a directory and information about the directory is not included in the application initial directory descriptor, the accumulation state notification unit 23 indicates that the accumulation of all the files in the directory has been completed. When it is detected, the storage standby unit 24 is notified of the storage completion ("stored") of the directory. In addition, the accumulation state notification unit 23, when all the files necessary for initial presentation (based on the definition in the application initial resource descriptor) among the files in the directory have been accumulated, The storage standby unit 24 is notified that the necessary data resource has been acquired ("stored_required").
(A-2) When the specified resource is a single file:
When the specified resource is a single file, the accumulation state notification unit 23 notifies the accumulation standby unit 24 of the completion of accumulation of the directory ("stored") when the accumulation completion of the file is detected. .

(B) When registering a listener without specifying a resource As described here, the function addDataResourceEventListener may be called without specifying resource_ref as a parameter.
In this case, when all the files in all the directories defined as “required for initial presentation” in the application initial directory descriptor in the AIT relating to the application to be started up have been accumulated, or the same When all the files defined as “required for initial presentation” in the application initial resource descriptor in the AIT have been accumulated, the accumulation state notification unit 23 indicates that “data resources necessary for initial presentation are acquired. “Completed” is notified to the storage standby unit 24 (“stored_required”).
In this case, the accumulation state notification unit 23 notifies the accumulation standby unit 24 of “accumulation completion” (“stored”) at the stage where accumulation of all the resources necessary for the application that is currently being activated is completed. .

  In either case (A) or (B) above, the storage standby unit 24 instructs the application execution unit 17 to start the initial presentation when the resources necessary for the initial presentation are available.

  In addition, you may make it implement | achieve a part of function of the receiver in embodiment mentioned above with a computer. In that case, a program for realizing the function of the receiver may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible disk, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, a “computer-readable recording medium” dynamically holds a program for a short time, like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory inside a computer system serving as a server or a client in that case may be included, and a program that holds a program for a certain period of time. The program may be a program for realizing a part of the above-described functions, or may be a program that can realize the above-described functions in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used for a business that provides contents such as video broadcasts such as television broadcasting, and a receiver for the business. Moreover, it is possible to utilize for the business which provides the application which operate | moves on such a receiver.

DESCRIPTION OF SYMBOLS 1 Receiver 3 Transmission apparatus 5 Server apparatus 11 Broadcast receiving part 12 Broadcast signal analysis part 13 AIT acquisition part (application information table acquisition part)
14 Communication Transmission / Reception Unit 15 Application Execution Control Unit 17 Application Execution Unit (Application Execution Unit)
21 File system (file storage unit)
22 File Accumulation Detection Unit 23 Accumulation Status Notification Unit 24 Accumulation Standby Unit 100 Television System

Claims (3)

A broadcast receiver for receiving broadcast signals;
An application information table acquisition unit for acquiring an application information table from the broadcast signal;
A file storage unit for acquiring and storing resource data related to the application specified in the acquired application information table;
File storage that acquires information indicating whether or not the resource data is essential for initial presentation from the application information table, and detects completion of initial presentation resource accumulation when the accumulation of resource data essential for initial presentation is completed A detection unit;
An accumulation state notification unit for notifying completion of initial presentation resource accumulation detected by the file accumulation detection unit;
Upon receiving the notification of the completion of initial presentation resource accumulation from the accumulation state notification unit, an accumulation standby unit that controls to start presentation by the application specified in the application information table;
An application execution unit that executes the application according to the control of the presentation start from the storage standby unit;
Equipped with,
The storage standby unit registers a listener for waiting for the resource data,
The storage status notification unit, through the registered listeners, which informs the initial presentation resource accumulation completed,
When the storage standby unit specifies the directory as a resource and registers the listener, and when the directory is not included in the information indicating whether the directory is resource data essential for the initial presentation, the storage The state notification unit, when the accumulation of all the files necessary for the initial presentation among the files in the directory is completed based on the information indicating whether the resource data is essential for the initial presentation, the initial presentation resource of the directory Notify the accumulation completion to the notification standby unit,
When the storage standby unit registers the listener without specifying a resource, the storage state notification unit is resource data that is essential for the initial presentation in the application information table related to the application that is currently starting. Based on the information indicating whether or not all files in all directories defined as essential for initial presentation have been accumulated, or all defined as essential for initial presentation When the file has been accumulated, notify the accumulation standby unit of the completion of initial presentation resource accumulation,
A receiver characterized by that. The file accumulation detection unit acquires information indicating whether or not the resource data is indispensable for initial presentation from the application initial directory descriptor included in the descriptor area of the application information table, or the application information Obtain information indicating whether or not the resource data is essential for initial presentation from the application initial resource descriptor included in the descriptor area of the table in units of resource data.
The receiver according to claim 1. Application information table acquisition means for acquiring an application information table from the broadcast signal received by the broadcast signal reception means;
File storage means for acquiring and storing resource data related to the application specified in the acquired application information table,
From the application information table, information indicating whether or not the resource data is essential for initial presentation is acquired for each resource data, and when the accumulation of the resource data essential for initial presentation is completed, the initial presentation resource accumulation is completed. File accumulation detection means to detect,
An accumulation state notification means for notifying completion of initial presentation resource accumulation detected by the file accumulation detection means;
Storage standby means for controlling to start presentation by the application specified in the application information table upon receiving notification of the completion of initial presentation resource accumulation from the accumulation state notification means,
Application execution means for executing the application according to the control of the presentation start from the storage standby means;
A program for causing a computer to function as,
The accumulation waiting means registers a listener for waiting for the resource data,
The accumulation state notifying means notifies the completion of initial presentation resource accumulation through the registered listener,
When the storage standby unit specifies the directory as a resource and registers the listener, and when the directory is not included in the information indicating whether the directory is resource data essential for the initial presentation, the storage The state notifying means, when the accumulation of all the files necessary for the initial presentation among the files in the directory is completed based on the information indicating whether or not the resource data is essential for the initial presentation, Notify the storage completion stand-by means of storage completion,
When the storage standby unit registers the listener without designating a resource, the storage state notification unit is resource data essential for the initial presentation in the application information table regarding the application that is currently starting. Based on the information indicating whether or not all files in all directories defined as essential for initial presentation have been accumulated, or all defined as essential for initial presentation When the file has been accumulated, notify the accumulation standby means of completion of initial presentation resource accumulation,
A program characterized by that.

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