KR20030085196A - Apparatus for protecting digital broadcasting program component by sections using an mpeg-4 system and a method thereof - Google Patents

Abstract

The present invention relates to an apparatus for protecting a section of a digital broadcast program component using an MPEG-4 system and a method thereof. In particular, the apparatus for protecting a section provides a corresponding program map by analyzing a transport stream including the digital broadcast program component. A transport stream analyzer extracting a table; Generating an IPMP descriptor for protecting the program component, and generating an object descriptor for interworking the generated IPMP descriptor for a specific section of the program component to be protected based on the program map table, A data generator for generating a new program map table connectable with the generated object descriptor; The program map table corresponding to the program element is modified to a new program map table generated by the data generator, a transport stream including the modified program map table, and an IPMP descriptor generated by the data generator. And a multiplexer for multiplexing and outputting an object descriptor into one transport stream. And a controller for controlling the transport stream analyzer, the data generator, and the multiplexer. According to the present invention, it is possible to control unauthorized access to various contents to be provided in a digital broadcasting environment and to increase utilization of a program or additional data.

Description

FIELD OF PROTECTING DIGITAL BROADCASTING PROGRAM COMPONENT BY SECTIONS USING AN MPEG-4 SYSTEM AND A METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multimedia data processing system and method, and more particularly, to an apparatus and method for protecting sections of digital broadcast program components using MPEG-4 system technology.

As broadcasting becomes digital, multi-channelization, high quality, and multifunctionalization have emerged as important elements of digital broadcasting. Especially, data broadcasting that provides multifunctionality satisfies the requirements of viewers by providing various additional data to viewers as well as programs. To make it possible.

In the conventional analog broadcast contents, as the number of copies increases, data deteriorates and the quality of the contents naturally degrades. In contrast, the digital broadcast contents have the same characteristics as the originals regardless of the number of copies. However, despite the explosive increase in digital broadcasting contents that can meet the requirements of viewers, much discussion has not been made regarding the management / protection of contents. In addition to the activation of the Internet, unauthorized copying and distribution of such digital contents has been a major problem. In the related MPEG-2 (MPEG-2: Moving Picture Experts Group-2) system standard, CA (Conditional Access) table is defined to receive restriction on broadcast program, but CA table is used for digital broadcast program or additional data. There is a problem that is not suitable for the content management / protection for each section.

In order to solve this problem, the present invention allocates the MPEG-4 basic ID descriptor to the program component to be protected among the MPEG-2 program or the additional data, which is a digital broadcasting program component, and protects the MPEG-4 basic ID descriptor. In order to achieve data protection for each component of digital broadcasting program by interworking IPMP (Intellectual Property Management and Protection, IPMP) descriptor stream by using MPEG-4 object descriptor in the program element section. The purpose is.

1 is a block diagram illustrating a device for protecting a section of a digital broadcast program or additional data using an MPEG-4 system according to an exemplary embodiment of the present invention.

2 is a diagram illustrating an object descriptor stream configuration according to an exemplary embodiment of the present invention.

3 is a relation explanatory diagram showing a relationship between an IPMP descriptor pointer and an IPMP descriptor according to an embodiment of the present invention.

4 is a diagram illustrating a transport stream configuration for section-by-section protection of a digital broadcast program or additional data using an MPEG-4 system according to an exemplary embodiment of the present invention.

5 is a flowchart illustrating a method for protecting a digital broadcasting program or additional data by section using an MPEG-4 system according to an exemplary embodiment of the present invention.

**** Explanation of symbols for the main parts of the drawing ****

100: MPEG-2 transport stream analysis unit 200: technician / table generation unit

300: data transmission format conversion unit 400: control unit

500: multiplexer 210: IPMP descriptor generation unit

220: object descriptor generation unit 230: program map table generation unit

310: IPMP descriptor transmission format conversion unit 320: object descriptor transmission format conversion unit

330: program map table transmission format conversion unit

According to one aspect of the present invention, there is provided a device for protecting a section of a digital broadcast program component.

A transport stream analyzer for analyzing a transport stream including the digital broadcast program component and extracting a corresponding program map table; Generating an IPMP descriptor for protecting the program component, and generating an object descriptor for interworking the generated IPMP descriptor for a specific section of the program component to be protected based on the program map table, A data generator for generating a new program map table connectable with the generated object descriptor; The program map table corresponding to the program element is modified to a new program map table generated by the data generator, a transport stream including the modified program map table, and an IPMP descriptor generated by the data generator. And a multiplexer for multiplexing and outputting an object descriptor into one transport stream. And a controller for controlling the transport stream analyzer, the data generator, and the multiplexer.

In addition, the apparatus converts the IPMP descriptor and the object descriptor generated in the data generator into a format for synchronization and transmission, and a data transmission format for converting the program map table generated in the data generator into a format for transmission. It further includes a conversion unit.

The data generation unit may include: an IP MP descriptor generation unit configured to generate the IP MP descriptor under the control of the controller; An object descriptor generator configured to generate an object descriptor including a pointer capable of designating the IPMP descriptor based on a program map table extracted by the transport stream analyzer under control of the controller; And a program map table generator for generating a new program map table to which an ID is assigned to enable connection with the generated object descriptor.

The data transmission format converter may further include: an IPMP descriptor transmission format converter for converting an IPMP descriptor generated by the data generator into a synchronization format and simultaneously converting the IPMP descriptor into a transmission format for transmission; An object descriptor transmission format conversion unit for converting the object descriptor generated by the data generation unit into a transmission format for synchronization and transmission; And a program map table transmission format conversion unit for converting the program map table generated by the data generation unit into a transmission format.

Meanwhile, the object descriptor is converted into a synchronization format in which the object descriptor and the IMP descriptor have time information so that the IMP descriptor may be linked to a specific section of the program component to protect the program component by section. It is characterized by.

In addition, according to another aspect of the present invention for achieving the above object, a method for protecting a section of a digital broadcast program component,

a) analyzing a transport stream containing the digital broadcast program component; b) using the analysis result, generating an IPMP descriptor for protecting the program component and an object descriptor for interworking the IPMP descriptor in a specific section of the program component to be protected; And c) multiplexing the transport stream with the generated IMP descriptor and the object descriptor.

In addition, the method further comprises converting the IPMP descriptor and the object descriptor into a format for synchronization and transmission after the generating step b).

At this time, in the analyzing step a), a program map table corresponding to the program element is extracted from the transport stream, and in the generating step b), the program map table can be connected to the object descriptor with reference to the extracted program map table. A new program map table is generated, and in the multiplexing step c), the generated program map table is multiplexed together with the transport stream, the IMP descriptor and the object descriptor.

In addition, the method further comprises, after the generating step b), converting the new program map table into a format for transmission.

Meanwhile, the generating step b) includes: i) generating an IPMP descriptor for protecting the program component; ii) generating an object descriptor including a pointer for designating the IPMP descriptor based on the program map table; And iii) generating a new program map table to which an ID is assigned to enable connection with the object descriptor.

In addition, the transmission format conversion step may include: i) converting the IPMP descriptor to a synchronization format and simultaneously to a transmission format; ii) converting the object descriptor to a synchronization format and simultaneously to a transmission format; And iii) converting the new program map table into a transmission format.

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

1 is a block diagram illustrating a protection apparatus for each section of a digital broadcast program or additional data using an MPEG-4 system according to an exemplary embodiment of the present invention.

As shown in FIG. 1, the apparatus for protecting a digital broadcasting program or additional data using an MPEG-4 system according to an embodiment of the present invention analyzes an MPEG-2 transport stream and extracts a program map table. -2 transport stream analyzer 100; A data generator 200 generating an IPMP descriptor, an object descriptor, and a new program map table; A data transmission format conversion unit 300 for converting an IPMP descriptor, an object descriptor, and a program map table (PMT) into a transmission format; Receives the transport stream analysis result data analyzed by the MPEG-2 transport stream analysis unit 100 and controls the data generator 200 to generate an IPMP descriptor, an object descriptor, and a program map table, and the data generator 200. A control unit 400 for controlling the data generated by the data transmission format conversion unit 300 to convert the transmission format so as to conform to the transmission standard; And a multiplexer 500 for multiplexing and outputting the IPMP descriptor, the object descriptor, and the new program map table converted by each transport format into one transport stream.

The MPEG-2 transport stream analyzer 100 receives an MPEG-2 transport stream including a digital broadcast program, extracts a program map table from program specific information (PSI), and configures a program stream. After analyzing the number of elementary packet identifiers (elementary_PID), the analysis data is output to the controller 400, and the MPEG-2 transport stream is output to the multiplexer 500.

The data generator 200 generates an IPMP descriptor for protecting a program or additional data, and outputs the IPMP descriptor to the IPMP descriptor transmission format converter 310 for converting into a transmission format for synchronization and transmission. ); Receives the analysis data for the program map table from the control unit 400, creates an object descriptor for interworking IPMP descriptors for audio, video or additional data to be protected, and converts the object descriptors into a transmission format for synchronization and transmission. An object descriptor generator 220 for outputting to the descriptor transmission format converter 320; And the MPEG-4 ES_ID is assigned to the audio or video, which is a program component to be protected, by receiving the program map table analysis data from the control unit 400 using the External_ES_ID_descriptor, generates a new program map table, and then transmits it. The program map table generator 230 outputs the program map table transmission format converter 330 to convert the format.

The data transmission format conversion unit 300 converts the IPMP descriptor input from the IPMP descriptor generation unit 210 into a synchronization format, converts the IPMP descriptor into a transmission format for transmission, and outputs the IPMP descriptor transmission format conversion unit to the multiplexer 500 ( 310); An object descriptor transmission format converter 320 for converting the object descriptor input from the object descriptor generator 220 into a transmission format for synchronization and transmission and outputting the same to the multiplexer 500; And a program map table transmission format conversion unit 330 for converting the program map table input from the program map table generation unit 230 into a transmission format and outputting the same to the multiplexer 500.

The controller 400 outputs the program map table analysis data input from the MPEG-2 transport stream analyzer 100 to the object descriptor generator 220 and the program map table generator 230, and analyzes the MPEG-2 transport stream. An operation control signal is input and output to each of the functional units of the unit 100, the data generator 200, the data transmission format converter 300, and the multiplexer 500.

The multiplexer 500 modifies the program map table of the MPEG-2 transport stream into the generated new program map table, and the IPMP descriptor and the object input from the modified MPEG-2 transport stream and the IPMP descriptor transport format converter 310. The object descriptor input from the descriptor transmission format conversion unit 320 is multiplexed into one stream and output.

Hereinafter, the operation of the protection device for each section of a digital broadcast program or additional data using the MPEG-4 system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

4 is a diagram illustrating a transport stream structure for protecting a digital broadcasting program or additional data using an MPEG-4 system according to an embodiment of the present invention, and FIG. 5 is an MPEG-4 system according to an embodiment of the present invention. Is a flowchart illustrating a method for protecting a digital broadcast program or additional data by section.

In order to protect content for each section of the MPEG-2 transport stream input from the outside, the controller 400 checks whether there is a component of content to be protected for each section for the input MPEG-2 transport stream (S100). If the content protection for each section for the MPEG-2 transport stream is not necessary, the controller 400 generates a control signal to the MPEG-2 transport stream analyzer 100 and passes the input MPEG-2 transport stream to multiplex it. The control unit 500 controls the multiplexing to end the data processing.

If the section-specific content protection for the MPEG-2 transport stream is checked, the MPEG-2 transport stream analyzer 100 extracts the program map table of the input MPEG-2 transport stream to determine the stream type, the number of streams, and the component program ID. (elementary_PID, hereinafter called elementary_PID) is analyzed (S110).

The MPEG-2 transport stream analyzer 100 transmits the analyzed data to the controller 400, and outputs the MPEG-2 transport stream to the multiplexer 500. The controller 400 transmits an operation control signal to the data generator 200 based on the analysis data received from the MPEG-2 transport stream analyzer 100.

The IPMP descriptor generator 210 of the data generator 200 generates an IPMP descriptor for protecting a program or additional data according to a control signal of the controller 400 (S131).

The object descriptor generator 220 generates an object descriptor including an IPMP descriptor pointer according to the control signal of the controller 400 (S132).

FIG. 2 is a diagram illustrating an object descriptor stream configuration according to an embodiment of the present invention. As shown in FIG. 2, each section of a digital broadcast program or additional data using MPEG-4 system technology according to an embodiment of the present invention. For protection, the IPMP descriptor stream can be interlocked using the MPEG-4 object descriptor in the section of the program element to be protected. As such, in order to interwork the IPMP descriptor stream, the controller 400 may control a descriptor update and a descriptor remove for each descriptor.

As shown in FIG. 2, an object descriptor stream configuration according to an embodiment of the present invention includes object descriptor update, object descriptor delete, IPMP descriptor update, IPMP descriptor delete, elementary stream descriptor (ES_Descriptor) element update (ES_Descriptor Update), and The base stream descriptor may be deleted, and each descriptor may be transmitted by a control signal of the controller 400 according to a specific time to be transmitted and a transmission need of each descriptor.

FIG. 3 is an explanatory diagram illustrating a relationship between an IPMP descriptor pointer and an IPMP descriptor according to an embodiment of the present invention. As shown in FIG. 3, the IPMP descriptor includes one or more IPMP descriptors and includes an object descriptor or an elementary stream descriptor. It is not directly included in the, but transmitted independently.

The object descriptor includes one or more elementary stream descriptors, an optional one or more IPMP descriptor pointers, and an optional one or more object content information descriptors (OCI_Descriptor), wherein the object descriptor or elementary stream descriptor is an IPMP descriptor pointer (IPMP_Descriptor Pointer). You can specify an IPMP descriptor, including).

If the object descriptor contains an IPMP descriptor pointer, it means that the IPMP descriptor is involved in all elementary stream descriptors belonging to the object descriptor. If the object descriptor or elementary stream descriptor contains an IPMP descriptor pointer, it is only concerned with the elementary stream descriptor. It means. Therefore, since the object descriptor is connected to the program component with the ES_ID and the IPMP descriptor with the IPMP descriptor pointer, the program component and the IPMP descriptor may interwork with each other due to the existence of the object descriptor. In addition, since the object descriptor and the IPMP descriptor are converted into a synchronization format having time information, the program component can be protected by sections by connecting the IPMP descriptor to a specific section of the program component.

At this time, the program map table generation unit 230 receives a control signal based on the transport stream analysis data analyzed from the control unit 400, and assigns a new MPEG-4 ES_ID to a program component that requires section-by-section protection. A program map table is generated (S133).

The MPEG-2 system standard defines and uses descriptors to specifically define the characteristics and specifications of each program element. The descriptor has an 8-bit descriptor_tag field for distinguishing it from other descriptors, and an 8-bit descriptor_length field for indicating length information.

In order to protect the digital broadcasting program or additional data using the MPEG-4 system according to an embodiment of the present invention, an external ES_ID descriptor ( The MPEG-4 ES_ID is allocated using the External_ES_ID_descriptor, hereinafter referred to as External_ES_ID_descriptor.

External_ES_ID_descriptor is a descriptor for assigning MPEG-4 ES_ID to a program element.

External_ES_ID_descriptor () {

descriptor_tag

descriptor_length

External_ES_ID

}

By using the property of External_ES_ID_descriptor, MPEG-4 ES_ID can be allocated to the program element to be protected. It can be implemented as follows.

TS_program_map_section () {

table_id

section_syntax_indicator

'0'

...

program_info_length

for (i = 0; I <N, I ++) {

descriptor ()

}

for (i = 0; i <N; I ++) {

stream_type

reserved

elementary_PID

reserved

ES_info_length

for (i = 0; i <N2; I ++) {

descriptor () <----- Insert External_ES_ID_descriptor

}

}

CRC_32

}

As described above, the MPEG-4 ES_ID value can be assigned to a program element having an arbitrary elementary_PID value by inserting External_ES_ID_descriptor into the second descriptor loop of the program map table. MPEG-2 audio, video or additional data assigned to the MPEG-4 ES_ID value can be controlled through the MPEG-4 system, and the program components can be protected by section by integrating the IPMP descriptor with the controlled program components. have.

The IPMP descriptor transmission format converting unit 310 receives a new IPMP descriptor generated from the IPMP descriptor generating unit 210, converts the input IPMP descriptor into a synchronization format, and converts it into a transmission format for transmission to the multiplexing unit 500. Output it (S134). At this time, the IPMP descriptor transmission format conversion unit 310 performs synchronization format conversion and transmission format conversion. The synchronization format includes the MPEG-4 SL (Sync Layer) format, the MPEG-4 FlexMux format, the MPEG-2 PES (Packetized Elementary Stream) format, and the transmission format includes the MPEG-2 transport stream format standard. do. The format conversion order is the MPEG-4 SL format, the MPEG-4 FlexMux format, the MPEG-2 PES format, and the MPEG-2 transport stream format.

The object descriptor transmission format converter 320 converts the object descriptor input from the object descriptor generator 220 into a transmission format for synchronization and transmission, and outputs it to the multiplexer 500 (S135). The object descriptor transmission format converter 320 performs a synchronization format conversion and a transmission format conversion. The synchronization format includes the MPEG-4 SL format, the MPEG-4 FlexMux format, the MPEG-2 PES format standard, and the transmission format includes the MPEG-2 transport stream format standard, and the format conversion order is MPEG-4. SL format, MPEG-4 FlexMux format, MPEG-2 PES format, MPEG-2 transport stream format.

The program map table transmission format conversion unit 330 converts the program map table input from the program map table generation unit 230 into a transmission format (S136). In this case, the program map table transmission format conversion unit 330 performs only transmission format conversion. The transport format includes the MPEG-2 transport stream format standard. Thereafter, the program map table transmission format converter 330 transmits the converted program map table to the multiplexer 500.

When the conversion is completed, the multiplexer 500 modifies the program map table of the MPEG-2 transport stream into a new program map table (S137), and converts the modified MPEG-2 transport stream, the IPMP descriptor data, and the object descriptor into one stream. Multiplex to (S140).

4 is a diagram illustrating a transport stream configuration for section-by-section protection of a digital broadcast program or additional data using an MPEG-4 system according to an exemplary embodiment of the present invention.

As shown in FIG. 4, a method of assigning an MPEG-4 ES_ID to the program element and a method of interworking an IPMP descriptor in a section of the program element are shown. The program map table is modified with the new program map table, and the modified MPEG-2 transport stream and IPMP descriptor data and object descriptors are multiplexed into one stream.

The System Time Clock (STC) defined by the MPEG-2 System Specification is a system time reference value operating at 27 MHz, so it is the default condition for synchronizing MPEG-4 object descriptors to MPEG-2 data. Let it work together. In addition, since the PCR (Program Clock Reference) defined in the MPEG-2 system standard is a program time reference value sampled at 90 kHz, in order to synchronize the MPEG-4 object descriptor with this program time reference value, the time reference value of the object descriptor and the IPMP descriptor is (OCR: Object Clock Reference) divided by an integer of 90 kHz. By this process, it is possible to synchronize the MPEG-4 object descriptor and the IPMP descriptor to audio or video or additional data to be protected. Therefore, program elements can be protected by section.

In the above description, the IPMP descriptor is linked to a specific section of the MPEG-2 transport stream by using the MPEG-4 object descriptor to protect a specific section of the MPEG-2 transport stream. The present invention is not limited to a digital broadcast program component, such as an audio, video, or additional data, a descriptor, for example, an IPMP descriptor, which is a protection means for a program component to be protected, is selected from a specific interlocking medium, for example, an MPEG-4 object. When interworking through a medium such as a descriptor, it may be applied to other types of transport streams.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and the present invention belongs to various substitutions, modifications, and changes that can be made without departing from the spirit and the gist of the present invention. Obviously, it is obvious to those skilled in the art, and the present invention is not limited only to the embodiments.

Sectional protection device and method of a digital broadcasting program or additional data using the MPEG-4 system of the present invention as described above enables the unauthorized access control of various contents to be provided in a digital broadcasting environment and utilize the program or additional data. There is an effect to increase.

Claims (16)

An apparatus for protecting a specific section of a digital broadcast program component, A transport stream analyzer for analyzing a transport stream including the digital broadcast program component and extracting a corresponding program map table; Create an IPMP (Intellectual Property Management and Protection) descriptor for protecting the program component and interwork the generated IPMP descriptor for a specific section of the program component to be protected based on the program map table. A data generator for generating an object descriptor for generating a new program map table connectable with the generated object descriptor; The program map table corresponding to the program element is modified to a new program map table generated by the data generator, a transport stream including the modified program map table, and an IPMP descriptor generated by the data generator. And a multiplexer for multiplexing and outputting an object descriptor into one transport stream. And Control unit for controlling the transport stream analyzer, data generator and multiplexer Sectional protection device for a digital broadcast program component comprising a. The method of claim 1, The apparatus further includes a data transmission format converter for converting the IPMP descriptor and the object descriptor generated by the data generator into a format for synchronization and transmission, and converting the program map table generated by the data generator into a format for transmission. Sectional protection device of the digital broadcast program component. The method of claim 1, The data generation unit An IP MP descriptor generation unit generating the IP MP descriptor under control of the controller; An object descriptor generator configured to generate an object descriptor including a pointer capable of designating the IPMP descriptor based on a program map table extracted by the transport stream analyzer under control of the controller; And Program map table generation unit for generating a new program map table assigned an ID (ID: identification) to enable the connection with the generated object descriptor Sectional protection device for a digital broadcast program component comprising a. The method of claim 2, The data transfer format conversion unit An IPMP descriptor transmission format converter for converting the IPMP descriptor generated by the data generator into a synchronization format and simultaneously converting the IPMP descriptor into a transmission format for transmission; An object descriptor transmission format conversion unit for converting the object descriptor generated by the data generation unit into a transmission format for synchronization and transmission; And A program map table transmission format conversion unit for converting the program map table generated by the data generation unit into a transmission format Sectional protection device for a digital broadcast program component comprising a. The method according to claim 2 or 4, The object descriptor and the IMP descriptor is converted into a synchronization format having time information so that the object descriptor can interlock the IMP descriptor to a specific section of the program component to protect the program component for each section. Sectional protection device of a digital broadcast program component. The method according to any one of claims 1 to 4, The digital broadcast program component is MPEG-2 audio, video and additional data, The transport stream is an MPEG-2 transport stream. Sectional protection device for a digital broadcast program component, characterized in that. The method of claim 6, The ID of the program map table connectable by the object descriptor is an elementary stream ID of MPEG-4. The elementary stream ID is assigned by an external elementary stream ID descriptor. Sectional protection device for a digital broadcast program component, characterized in that. In the method for protecting a specific section of the digital broadcast program component, a) analyzing a transport stream containing the digital broadcast program component; b) using the analysis result, generating an IPMP descriptor for protecting the program component and an object descriptor for interworking the IPMP descriptor in a specific section of the program component to be protected; And c) multiplexing and outputting the transport stream with the generated IMP descriptor and the object descriptor; Sectional protection method of a digital broadcast program component comprising a. The method of claim 8, In the analyzing step a), a program map table corresponding to the program component is extracted from the transport stream, In the generating step b), a new program map table connectable to the object descriptor is generated with reference to the extracted program map table. In the multiplexing step c), the generated program map table is multiplexed with the transport stream, the IMP descriptor and the object descriptor. A method for protecting sections by periods of a digital broadcast program component. The method of claim 8, And after the generating step b), converting the IPMP descriptor and the object descriptor into a format for synchronization and transmission. The method of claim 9, And after the generating step b), converting the new program map table into a format for transmission. The method of claim 9, The generating step b) i) creating an IPMP descriptor to protect the program component; ii) generating an object descriptor including a pointer for designating the IPMP descriptor based on the program map table; And iii) creating a new program map table assigned an ID to enable connection with the object descriptor; Sectional protection method of a digital broadcast program component comprising a. The method of claim 11, The transfer format conversion step i) converting the IPMP descriptor to a synchronization format and simultaneously to a transmission format; ii) converting the object descriptor to a synchronization format and simultaneously to a transmission format; And iii) converting the new program map table into a transfer format Sectional protection method of a digital broadcast program component comprising a. The method according to any one of claims 8 to 13, The digital broadcast program component is MPEG-2 audio, video and additional data, The transport stream is an MPEG-2 transport stream. Sectional protection device for a digital broadcast program component, characterized in that. The method of claim 14, The ID of the program map table connectable by the object descriptor is an elementary stream ID of MPEG-4. The elementary stream ID is assigned by an external elementary stream ID descriptor. Sectional protection device for a digital broadcast program component, characterized in that. The method of claim 13, In the IPMP descriptor transmission format conversion step i) and the object descriptor transmission format conversion step ii), When converting the synchronization format, conversion is performed in the order of MPEG-4 SL (Sync Layer) format, MPEG-4 FlexMux format, and MPEG-2 PES (Packetized Elementary Stream) format. The transport format conversion is performed after the synchronization format conversion, and is an MPEG-2 transport stream format conversion. A method for protecting sections by periods of a digital broadcast program component.