Digital broadcast receiving apparatus, digital broadcast apparatus, digital broadcast receiving method, digital broadcast method, and digital broadcast receiving program

• US 20050105537A1
• Filed: 02/19/2004
• Published: 05/19/2005
• Est. Priority Date: 02/20/2003
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Motomura, Naohisa
• Granted Patent: US 7,555,019 B2
• Time in Patent Office: Days
• US Class Current: 370/395.640
• CPC Class Codes: H04H 20/16 Arrangements for broadcast or for distribution of identical information repeatedly
• CPC Class Codes: H04H 40/18 Arrangements characterised by circuits or components specially adapted for receiving
• CPC Class Codes: H04N 21/235 Processing of additional data, e.g. scrambling of additional data or processing content descriptors
• CPC Class Codes: H04N 21/2362 Generation or processing of Service Information [SI]
• CPC Class Codes: H04N 21/434 Disassembling of a multiplex stream, e.g. demultiplexing audio and video streams, extraction of additional data from a video stream; Remultiplexing of multiplex streams; Extraction or processing of SI; Disassembling of packetised elementary stream demultiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00
• CPC Class Codes: H04N 21/4345 Extraction or processing of SI, e.g. extracting service information from an MPEG stream
• CPC Class Codes: H04N 21/435 Processing of additional data, e.g. decrypting of additional data, reconstructing software from modules extracted from the transport stream

Abstract

A digital broadcast system is provided in which, during the control of caching the tables multiplexed onto a transport stream, the caching is optimally updated without wasting filter resources on changes such as updates to a higher version, addition, or disappearance of the tables. The digital broadcast apparatus broadcasts a transport stream onto which an available table information table (ATT) is multiplexed. The ATT monitoring unit in the receiving apparatus regularly monitors an update in the ATT and generates an available table information list every time the ATT has been updated to a higher version. The cache controlling unit compares the available table information list with a cache information list, (i) assigns a filter resource and updates the cache of the table when there is a table updated to a higher version or added, and (ii) clears the cache of the table when there is a table that has disappeared.

Claims

1. A digital broadcast receiving apparatus that receives a transport stream onto which video data and/or audio data are multiplexed and outputs video data and/or audio data, comprising:

a first extracting unit that has a packet filter and a section filter and is operable to extract one or more of tables, each of which (i) is repeatedly multiplexed onto the transport stream, (ii) is contained in a transport stream packet in a section format, (iii) is identified with a packet identifier and a table identifier, and (iv) includes information for extracting and outputting the video data and/or the audio data;

a storing unit operable to store therein the extracted tables;

a second extracting unit operable to extract an information table that is repeatedly multiplexed onto the transport stream and includes (i) apiece of table ID information and a table version number of each of the tables and (ii) an information table version number of the information table, which is to be updated when there is a change in any one of the pieces of table ID information and the table version numbers, the extraction being performed when the information table version number has been updated; and

a controlling unit operable to analyze the extracted information table, have the first extracting unit extract, based on table ID information, such a table whose table version number has been updated, and have the storing unit update what is stored therein, wherein

the controlling unit includes;

an information list generating subunit operable to generate an information list that includes such information of the tables stored in the storing unit that corresponds to the information table;

a comparing subunit operable to compare table version numbers written in the information list with the table version numbers in the information table extracted by the second extracting unit; and

a filter condition setting subunit operable to set a packet identifier and a table identifier of such a table whose table version number written in the information table is found updated by the comparing subunit, as a packet filter and a section filter, respectively.

2. The digital broadcast receiving apparatus of claim 1, wherein

the pieces of table ID information written in the information table are the packet identifiers and the table identifiers of the tables.

3. The digital broadcast receiving apparatus of claim 1, wherein

extraction conditions at the packet filter and the section filter of the first extracting unit are set by the filter condition setting subunit, and

when the first extracting unit extracts a table, and the storing unit stores therein this table having an old table version number attached, the first extracting unit overwrites the table having the old table version number with the extracted table.

4. The digital broadcast receiving apparatus of claim 1, wherein

the information table further includes a flag that indicates whether each of the tables is being multiplexed onto the transport stream or not, and

the controlling unit further includes

a deleting subunit operable to delete, from the storing unit and the information list, such a table that is indicated by the flag as not being multiplexed.

5. The digital broadcast receiving apparatus of claim 4, wherein

the information table further includes a validity period of each of the tables, and

the controlling unit further includes:

a schedule generating subunit operable to generate a schedule for extracting a table at a beginning of its validity period and for deleting a table at an end of its validity period; and

the filter condition setting subunit and the deletion subunit operate according to the schedule.

6. A digital broadcast apparatus comprising:

a first multiplexing unit operable to multiplex video data and/or audio data onto a transport stream;

a second multiplexing unit operable to repeatedly multiplex tables on the transport stream in a section format, the tables each including information used for extraction and output of video data and/or audio data performed by a receiving apparatus and being identified by a packet identifier and a table identifier;

a third multiplexing unit operable to repeatedly multiplex, onto the transport stream, an information table that includes (i) a piece of table ID information and a table version number of each of the tables and (ii) an information table version number of the information table, which is to be updated when any one of the tables is updated; and

a transmitting unit operable to transmit the transport stream, on which the first, second, and third multiplexing units have performed the multiplexing, to the receiving apparatus.

7. A digital broadcast receiving method for receiving a transport stream onto which video data and/or audio data are multiplexed and outputting video data and/or audio data, comprising:

a first extracting step of, with use of a packet filter and a section filter, extracting one or more of tables, each of which (i) is repeatedly multiplexed onto the transport stream, (ii) is contained in a transport stream packet in a section format, (iii) is identified with a packet identifier and a table identifier, and (iv) includes information for extracting and outputting the video data and/or the audio data;

a recording step of recording the extracted tables in a storage area;

a second extracting step of extracting an information table that is repeatedly multiplexed onto the transport stream and includes (i) a piece of table ID information and a table version number of each of the tables and (ii) an information table version number of the information table, which is to be updated when there is a change in any one of the pieces of table ID information and the table version numbers, the extraction being performed when the information table version number has been updated; and

a controlling step of analyzing the extracted information table, having the first extracting step extract, based on table ID information, such a table whose table version number has been updated, and having what has been recorded in the recording step updated, wherein

the controlling step includes;

an information list generating substep of generating an information list that includes such information of the tables recorded in the recording step that corresponds to the information table;

a comparing substep of comparing table version numbers written in the information list with the table version numbers in the information table extracted in the second extracting step; and

a filter condition setting step of setting a packet identifier and a table identifier of such a table whose table version number written in the information table is found updated by the comparing substep, as a packet filter and a section filter, respectively.

8. A digital broadcast method comprising:

a first multiplexing step of multiplexing video data and/or audio data onto a transport stream;

a second multiplexing step of repeatedly multiplexing tables on the transport stream in a section format, the tables each including information used for extraction and output of video data and/or audio data performed by a receiving apparatus and being identified by a packet identifier and a table identifier;

a third multiplexing step of repeatedly multiplexing, onto the transport stream, an information table that includes (i) a piece of table ID information and a table version number of each of the tables and (ii) an information table version number of the information table, which is to be updated when any one of the tables is updated; and

a transmitting step of transmitting the transport stream, on which the first, second, and third multiplexing steps have performed the multiplexing, to the receiving apparatus.

9. A digital broadcast receiving program to be applied to a digital broadcast receiving apparatus that receives a transport stream onto which video data and/or audio data are multiplexed and outputs video data and/or audio data, comprising:

a first extracting step of, with use of a packet filter and a section filter, extracting one or more of tables, each of which (i) is repeatedly multiplexed onto the transport stream, (ii) is contained in a transport stream packet in a section format, (iii) is identified with a packet identifier and a table identifier, and (iv) includes information for extracting and outputting the video data and/or the audio data;

a recording step of recording the extracted tables in a storage area;

a second extracting step of extracting an information table that is repeatedly multiplexed onto the transport stream and includes (i) a piece of table ID information and a table version number of each of the tables and (ii) an information table version number of the information table, which is to be updated when there is a change in any one of the pieces of table ID information and the table version numbers, the extraction being performed when the information table version number has been updated; and

a controlling step of analyzing the extracted information table, having the first extracting step extract, based on table ID information, such a table whose table version number has been updated, and having what has been recorded in the recording step updated, wherein

the controlling step includes;

an information list generating substep of generating an information list that includes such information of the tables recorded in the recording step that corresponds to the information table;

a comparing substep of comparing table version numbers written in the information list with the table version numbers in the information table extracted in the second extracting step; and

a filter condition setting step of setting a packet identifier and a table identifier of such a table whose table version number written in the information table is found updated by the comparing substep, as a packet filter and a section filter, respectively.