JP4334434B2 - Digital broadcast receiver - Google Patents

Description

  The present invention relates to a digital broadcast receiving device, a digital broadcast receiving method, and a digital broadcast receiving program, and more particularly to a digital broadcast receiving device, a digital broadcast receiving method, and a digital broadcast receiving program that receive BS digital broadcast or terrestrial digital broadcast. .

  The contents of the data broadcasting service for digital terrestrial broadcasting are composed of BML (Broadcast Markup Language) documents, image data, and the like, and are transmitted by one or a plurality of modules. As a system for transmitting this module, a DSM-CC (Digital Storage Media Command and Control) data carousel transmission system is adopted.

  FIG. 8 shows a data structure used in the DSM-CC data carousel transmission system.

  Referring to the figure, the module is divided into data of a common size called a block. A block is divided into one or a plurality of blocks, and a block header is added to each block. The divided data to which the block header is added is further added with a section packet header and CRC data to form a unit called a DSM-CC section. The DSM-CC section is divided into data of a common size in order to be multiplexed into a transport stream defined by the MPEG (Moving Picture Coding Experts Group) 2 Systems (ISO / IEC 13818-1) standard. This divided data becomes a payload of the TS (transport stream).

  The TS packet has a fixed length of 188 bytes, and includes a 4-byte packet header, an adaptation field for transmitting additional information related to the stream, and a payload. In addition, only one of the adaptation field and the payload may be a constituent element of the TS packet.

  Various information such as video, audio and data is transmitted by the transport stream in which the TS packets are multiplexed.

  In the DSM-CC data carousel transmission method, modules divided in units of TS packets are arranged in a virtual rotating body called a carousel, and are repeatedly transmitted based on the rotation of the carousel. For this reason, even if the data broadcasting service starts to be viewed from the middle, it is possible to acquire all of the modules by combining a part of the module received this time with a part of the module transmitted next time. You can watch the broadcast service from the beginning to the end.

  In the DSM-CC data carousel transmission system, a plurality of modules are periodically transmitted to form one carousel. The period of repeated transmission for each module (hereinafter referred to as a retransmission period) is usually different. Furthermore, in the data broadcasting service, there are a plurality of carousels. A carousel is also called a component from the aspect of a component of a broadcast program.

  FIG. 9 shows a conceptual diagram of data transmission performed in the DSM-CC data carousel transmission system.

  Referring to the figure, in carousel 1, module 0 and module 1 are transmitted.

  Here, the Z-th DSM-CC section belonging to the module Y transmitted in the carousel X is defined as a DSM-CC section X · YZ.

  The module 0 includes a DSM-CC section 1 • 00, a DSM-CC section 1 • 01, and a DSM-CC section 1 • 02.

  The module 1 includes a DSM-CC section 1 • 00, a DSM-CC section 1 • 01, a DSM-CC section 1 • 02, and a DSM-CC section 1 • 03.

  Further, the retransmission period of module 0 is shorter than that of module 1.

  Next, in the carousel 2, only the module 0 is transmitted.

  Module 0 is composed of a DSM-CC section 2.00 and a DSM-CC section 2.01.

  FIG. 10 shows a detailed structure of a section defined by the MPEG2 Systems (ISO / IEC 13818-1) standard.

  Referring to the figure, the section includes a table identification that defines the table to which the section belongs, a section syntax instruction that indicates the syntax of the section, a section length that indicates the number of bytes from immediately after this field to the end of the section, sub The table identification extension used to define the table, the version number indicating the version of the section, the current next indication that indicates whether the section is the current version or the next version, and in the subtable The header is composed of the last section number indicating the last section number, the main body data, and the CRC indicating the CRC (Cyclic Redundancy Code) value of the section.

  FIG. 11 shows a detailed structure of a TS packet defined by the MPEG2 Systems (ISO / IEC 13818-1) standard.

  Referring to the figure, a TS packet is composed of a synchronization byte (8 bits) indicating the head of the packet, a transport error indicator (1 bit) indicating the presence or absence of an error in the packet, and a payload of a new transport packet. Payload unit start indicator (1 bit) indicating the start, transport priority (1 bit) indicating the importance of this packet, packet identifier (PID, 13 bits) for identifying this packet, payload Transport scramble control (2 bits) indicating presence / absence of scramble, adaptation field control (2 bits) indicating presence / absence of adaptation field and presence / absence of payload, and whether or not a packet having the same PID is partially discarded Cyclic counter for detection ( 15) a packet header consisting of continuity indicator (4 bits) which is composed of the above-described adaptation field and / or payload.

  In the TS packet including the head of the section, a pointer field (8 bits) is arranged at the head of the payload and the head position of the section in the payload is specified. However, in the DSM-CC section, the pointer field is always zero. And a section is placed immediately after the pointer field.

  Here, different packet identifiers are assigned to video, audio and data. In the DSM-CC data carousel transmission method, different packet identifiers are assigned to each carousel. Therefore, the digital broadcast receiving apparatus can separate video data and audio data based on this packet identifier, and can further separate carousels.

  In addition, in terrestrial digital broadcasting services for mobile terminals, mobile reception is performed, so the reception environment is unstable, and received TS packets often contain errors.

  In general, in a receiving apparatus that employs a DSM-CC data carousel transmission system, content can be generated in units of components or modules by combining with other components or modules. However, when an error is detected for a TS packet which is a smaller unit, the stored TS packet is discarded. Then, the digital broadcast receiving apparatus restarts the generation of the DSM-CC section from the beginning by using the TS packet belonging to the same DSM-CC section that is retransmitted thereafter. Therefore, when there is an error in the TS packet, the time for generating the DSC-CC section becomes long.

  The reason why the stored TS packet is discarded and the generation of the DSM-CC section is performed again is because the TS packet received by retransmission does not know which section of the packet.

  On the other hand, in Patent Document 1, the arrangement information indicating which section of which section the TS packet is in the option field (FIG. 11C) in the adaptation field (FIG. 11B). Is inserted into the transport private data area.

Thereby, in Patent Document 1, when an error is detected in a TS packet, the generation of the DSM-CC section is continued without discarding the stored TS packet, and the arrangement information of the TS packet received by retransmission is referred to Thus, only the unacquired TS packet can be stored to complete the DSC-CC section.
JP 2004-23379 A

  However, the method described in Patent Document 1 has the following problems because it is necessary to include the above-described arrangement information in the TS packet.

  First, it is necessary to generate a TS packet including arrangement information on the broadcast station side, which may force a change in the specifications of the apparatus on the broadcast station side.

  Moreover, since the TS packet includes the sequence information, the transmission efficiency of broadcast data sent from the broadcast station is lowered.

  SUMMARY OF THE INVENTION Therefore, an object of the present invention is to receive a TS packet that does not include information indicating what number of packet in which section, and to reconstruct a section from the TS packet in a short time. , A digital broadcast receiving method, and a digital broadcast receiving program.

Digital broadcast receiving apparatus according to the present invention is a digital broadcast receiver for receiving digital broadcasting section is a transfer unit is sent repeatedly, the temporary means for receiving a transport stream packet, the received packet estimating a storing means for storing, and a section acquisition unit for reconstructing a section from the received packet, the section acquisition unit, a packet number received packet indicates what number of packets section in It means for, when the received packet is not stored in the storage means, and hand-stage writing the packet in the storage means, when acquiring all the packets belonging to one section, reconstruct the section comprising means for said means for estimation, including a head portion of the latest packet received to date sections No time, continuity index in the latest packet continuity index contained in the last packet received last, and based on the packet number of the last packet, estimating a packet number of the latest packet.

  Preferably, the cache control unit deletes the packet belonging to the reconfigured section from the storage unit after the section is reconfigured.

  Preferably, the cache control unit further overwrites the packet stored in the latest received packet when the estimated packet number matches the bucket number of the packet stored in the storage unit.

  Preferably, when the estimated packet number matches the bucket number of the packet stored in the storage unit, the cache control unit further stores the latest received packet content in the storage unit having the same packet number. Only when the contents of the stored packet do not match, the packet stored in the storage means is overwritten with the latest received packet.

  Preferably, the section acquisition unit further includes means for calculating the number of packets of the section to which the packet belongs based on the section length in the packet when the latest received packet includes a head portion of the section, and the latest reception If the calculated packet does not include the head part of the section, it is determined whether or not the estimated packet number is a packet number of a packet belonging to the section based on the calculated number of packets. When it is determined that the packet number does not belong to the section, a means for determining that the section switching has occurred and a packet including the head part of the section are acquired when it is determined that the section switching has occurred. Until the section acquisition process by other components in the section acquisition section And a section acquisition control means for stopping.

  Preferably, the section acquisition unit further stores a packet belonging to the section of the section number in the most recently received packet stored in the storage means when the most recently received packet includes a head portion of the section. Including a means for determining whether the section version in the latest received packet and the section version of the packet belonging to the section stored in the storage means are the same, and the cache control means determines that the section versions are not the same When it is done, the packet belonging to the section stored in the storage means is deleted.

  Preferably, the digital broadcast receiving apparatus further includes error control means for incrementing all error packet number counters provided for each packet identifier when an error is set in the transport error indicator of the received packet. In addition, the section acquisition unit further determines that the error packet number counter value of the packet identifier of the most recently received packet exceeds a predetermined value when no error is set in the transport error indicator of the most recently received packet. When it is determined that section switching has occurred and the error packet number counter value of the packet identifier is less than or equal to a predetermined value, the means of resetting the error packet number counter of the packet identifier and section switching occur When it is determined that Until obtaining a packet including the head portion of transfection, and a section acquisition control means for stopping the process of acquiring sections with other components in the section acquisition unit.

  The digital broadcast receiving method according to the present invention is a digital broadcast receiving method of a digital broadcast receiving apparatus for receiving a digital broadcast in which a section as a transfer unit is repeatedly transmitted, the step of receiving an MPEG2 transport stream packet; A section acquisition step for reconstructing a section from the received packet, wherein the section acquisition step includes a continuity included in the most recently received packet when the most recently received packet does not include a head portion of the section. Estimating a packet number representing the number of the most recently received packet in the section to which it belongs based on the index and the continuity index included in the last received packet; If the packet with the packet number is not stored in the storage means In, including a cache control step of writing the received packet to the latest in the storage means, when the acquired all the packets belonging to one section, and a step of reconstructing a section from all the packets belonging to the section.

  Preferably, the cache control step erases the packet belonging to the reconfigured section from the storage means after the reconfiguration of the section.

  Preferably, the cache control step further overwrites the packet stored in the latest received packet when the estimated packet number matches the bucket number of the packet stored in the storage means.

  Preferably, in the cache control step, when the estimated packet number matches the bucket number of the packet stored in the storage unit, the latest received packet content is stored in the storage unit having the same packet number. Only when the contents of the stored packet do not match, the packet stored in the storage means is overwritten with the latest received packet.

  Preferably, the section obtaining step further includes a step of calculating the number of packets of the section to which the packet belongs based on the section length in the packet when the latest received packet includes a head portion of the section, and the latest reception If the calculated packet does not include the head part of the section, it is determined whether or not the estimated packet number is a packet number of a packet belonging to the section based on the calculated number of packets. When it is determined that the packet number does not belong to a section, a step for determining that a section switch has occurred, and a packet including a head portion of the section is acquired when it is determined that a section switch has occurred. Until the section acquisition processing is canceled And a control step.

  Preferably, the section obtaining step further includes the step of storing the packet belonging to the section of the section number in the most recently received packet in the storage means when the most recently received packet includes a head portion of the section. Including a step of determining whether a section version in the latest received packet is the same as a section version of a packet belonging to the section stored in the storage means, and the cache control step determines that the section version is not the same When it is done, the packet belonging to the section stored in the storage means is deleted.

  Preferably, the digital broadcast receiving method further includes the step of incrementing all of the error packet number counters provided for each packet identifier when an error is set in the transport error indicator of the received packet. In the acquisition step, when an error is not set in the transport error indicator of the most recently received packet, the error packet number counter value of the packet identifier of the most recently received packet exceeds a predetermined value. When it is determined that a section switching has occurred and the error packet number counter of the packet identifier is less than or equal to a predetermined value, the step of resetting the error packet number counter of the packet identifier and the section switching have occurred When judged , Until you get the packet including the head portion of the section, and a section acquisition control step to stop the acquisition processing section.

  A digital broadcast receiving program according to the present invention is a digital broadcast receiving program for receiving a digital broadcast in which a section as a transfer unit is repeatedly transmitted in a digital broadcast receiving apparatus. A step of receiving a packet and a section acquisition step of reconstructing a section from the received packet are executed, and the section acquisition step is performed when the latest received packet does not include a head portion of the section. Based on the continuity index included in the packet and the continuity index included in the previously received packet, the packet number that represents the number of the packet in the section to which the latest received packet belongs is estimated. And the estimated packet A cache control step for writing the latest received packet to the storage means when the numbered packet is not stored in the storage means, and all packets belonging to a section when all packets belonging to one section are obtained. Reconstructing the section from the packet.

  Preferably, the cache control step erases the packet belonging to the reconfigured section from the storage means after the reconfiguration of the section.

  Preferably, the cache control step further overwrites the packet stored in the latest received packet when the estimated packet number matches the bucket number of the packet stored in the storage means.

  Preferably, in the cache control step, when the estimated packet number matches the bucket number of the packet stored in the storage unit, the latest received packet content is stored in the storage unit having the same packet number. Only when the contents of the stored packet do not match, the packet stored in the storage means is overwritten with the latest received packet.

  Preferably, the section obtaining step further includes a step of calculating the number of packets of the section to which the packet belongs based on the section length in the packet when the latest received packet includes a head portion of the section, and the latest reception If the calculated packet does not include the head part of the section, it is determined whether or not the estimated packet number is a packet number of a packet belonging to the section based on the calculated number of packets. When it is determined that the packet number does not belong to a section, a step for determining that a section switch has occurred, and a packet including a head portion of the section is acquired when it is determined that a section switch has occurred. Until the section acquisition processing is canceled And a control step.

  Preferably, the section obtaining step further includes the step of storing the packet belonging to the section of the section number in the most recently received packet in the storage means when the most recently received packet includes a head portion of the section. Including a step of determining whether a section version in the latest received packet is the same as a section version of a packet belonging to the section stored in the storage means, and the cache control step determines that the section version is not the same When it is done, the packet belonging to the section stored in the storage means is deleted.

  Preferably, the digital broadcast receiving program further includes a step of incrementing all of the error packet number counters provided for each packet identifier when an error is set in the transport error indicator of the received packet. In the section acquisition step, the error packet number counter value of the packet identifier of the most recently received packet exceeds the predetermined value when no error is set in the transport error indicator of the most recently received packet. When the section switching is determined to occur, and the error packet number counter of the packet identifier is less than a predetermined value, the step of resetting the error packet number counter of the packet identifier and the section switching Including when it is determined to have occurred, until you get the packet including the head portion of the section, and a section acquisition control step to stop the acquisition processing section.

  According to the present invention, it is possible to receive a packet that does not contain information indicating what number of packet in which section, and to reconstruct the section from the packet in a short time.

  The data structure used in the DSM-CC data carousel transmission system in the embodiment of the present invention is the same as that shown in FIG. 8, and the concept of data transmission performed in the DSM-CC data carousel transmission system is shown in FIG. The detailed structure of the section is the same as that shown in FIG. 10, and the detailed structure of the TS packet is the same as that shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Configuration of digital broadcast receiver)
FIG. 1 is a functional block diagram of a digital broadcast receiving apparatus according to an embodiment of the present invention. Referring to the figure, this digital broadcast receiving apparatus includes a tuner 1, a demodulator 2, a TS decode processor 3, an audio decode processor 4, a video decode processor 5, a presentation processor 6, A browser request processing unit 7, a browser 8, a RAM 9, and a CPU 10 are included.

  The tuner 1 receives a digital broadcast signal, performs frequency conversion from an RF (Radio Frequency) band to a baseband band, and outputs the baseband signal to the demodulation unit 2.

  The demodulator 2 receives the baseband signal and extracts a plurality of TS packets from the demodulated signal obtained by demodulating the baseband signal. Then, the demodulation unit 2 performs error detection processing on the TS packet, and when an error is detected, information indicating an error is inserted into the transport error indicator of the packet header in the TS packet.

  The TS decode processing unit 3 receives the TS packet, and based on the packet identifier of the packet header, the TS packet corresponding to the audio signal (hereinafter referred to as an audio TS packet) and the TS packet corresponding to the video signal (hereinafter referred to as the video). TS packets) and TS packets corresponding to data (hereinafter referred to as data TS packets) are identified. Then, the TS decode processing unit 3 outputs the audio TS packet to the audio decode processing unit 4 and outputs the video TS packet to the video decode processing unit 5. The TS decode processing unit 3 generates a module from a plurality of data TS packets and outputs the module to the browser request processing unit 7. Details of the TS decode processing unit 3 will be described later.

  The audio decoding processing unit 4 receives the audio TS packet, performs MPEG-2 standard decoding processing, generates audio data, and outputs it to the outside.

  The video decoding processing unit 5 receives the video TS packet, performs a decoding process of the MPEG-2 standard, generates video data, and outputs the video data to the presentation processing unit 6.

  The browser request processing unit 7 receives the module from the TS decoding processing unit 3 and outputs the module requested from the browser 8 to the browser 8. Here, the browser 8 notifies the necessary module to the browser request processing unit 7 by outputting a control signal to the browser request processing unit 7 via the system bus.

  The browser 8 receives the module from the browser request processing unit 7 and extracts content, that is, a BML document and image data from the module. Then, the browser 8 performs these layouts and outputs them to the presentation processing unit 6.

  The presentation processing unit 6 generates a presentation screen that combines the laid-out content and the video data received from the video decoding processing unit 5, and outputs the generated presentation screen to the outside.

  The RAM 9 stores data necessary for control performed by the CPU 10.

  The CPU 10 performs various controls on each functional block via the system bus.

(Configuration of TS decode processing unit 3)
FIG. 2 is a functional block diagram of the TS decode processing unit 3 in the digital broadcast apparatus according to the present embodiment. Referring to FIG. 3, TS decode processing unit 3 includes a PID (Packet Identification) filter unit 21 and a carousel reception processing unit 22.

  The error control unit 41 receives a TS packet, checks a transport error indicator in the TS packet, and when an error is set in the transport error indicator, an error packet number counter provided for each filter (that is, for each PID). Are all incremented, and the value of the error packet counter is output to the carousel receiver 22. Further, the error control unit 41 outputs a TS packet to the PID filter unit 21 when no error is set in the transport error indicator.

  The PID filter unit 21 receives a TS packet from the error control unit 41 and receives a filtering number designated as a filtering target from the CPU 10 via the system bus. Here, it is assumed that the filtering number and the PID have a one-to-one correspondence. Therefore, the filtering number designated as the filtering target is also referred to as PID information.

  When the PID of the received TS packet is the PID of the voice TS packet and the filtering number corresponding to the PID is designated as a filtering target, the PID filter unit 21 decodes the TS packet as a voice TS packet. Output to the processing unit 4.

  When the received PID of the TS packet is the PID of the video TS packet and the filtering number corresponding to the PID is designated as the filtering target, the PID filter unit 21 decodes the video as a video TS packet. Output to the processing unit 5.

  In addition, when the PID of the received TS packet is the PID of the data TS packet and the filtering number corresponding to the PID is designated as a filtering target, the PID filter unit 21 converts the received TS packet into the data TS. The packet is output to the carousel reception processing unit 22 as a packet.

  The carousel reception processing unit 22 generates a module from a plurality of data TS packets and outputs the module to the browser request processing unit 7. Details of the carousel reception processing unit 22 will be described below.

(Configuration of the carousel reception processing unit 22)
FIG. 3 is a functional block diagram of the carousel reception processing unit 22 in the digital broadcast apparatus according to the present embodiment.

  Referring to FIG. 4, carousel reception processing unit 22 includes a section acquisition unit 30 and a section request unit 48. The section acquisition unit 30 includes a section acquisition control unit 43, a packet number estimation unit 44, a section switching determination unit 45, a packet number calculation unit 46, a section version determination unit 49, a cache control unit 35, a RAM 36, And a section reconstruction unit 47.

  The section acquisition control unit 43 sets the filter number corresponding to the PID of the TS packet received from the PID filter unit 21 to the current filter number fn.

  Further, the section acquisition control unit 43 checks whether or not the start is set in the bay load unit start indicator in the received TS packet, and when the start is set, the section acquisition control unit 43 describes the constituent elements in the section acquisition unit 30 as described later. When the start packet processing is performed and the start is not set, the constituent elements within the section acquisition unit 30 perform non-first packet processing described later.

  Further, the section acquisition control unit 43 sets the section number in the TS packet including the head portion (that is, the section header) of the received section as the current section number sn.

  Also, the section acquisition control unit 43 cancels the setting of the section acquisition flag for the current filter number fn when the section switching determination unit 45 determines that the section has been switched, and other configurations in the section acquisition unit 30 The element is made to stop the section acquisition process until the TS packet including the head part of the section is acquired.

  The packet number estimation unit 44 sets the current filter number section acquisition flag to a set, and when the received TS packet is a packet that does not include the head portion, the current continuity counter CCc value (that is, the latest And the value of the previous continuity counter CCp [fn] of the current filter number fn (that is, among the TS packets having the PID corresponding to the current filter number fn). When the current continuity counter CCc value is larger than the previous continuity counter CCp [fn] value of the current filter number fn, the current continuity counter CCc Value, the value of the previous continuity counter CCp [fn] of the current filter number fn, and the previous packet number PN of the current filter number fn By using the [fn], PNp the packet number PNc the received TS packet [fn] + (Ccc-CCp [fn]) and estimated. Further, when the current continuity counter CCc value is equal to or smaller than the previous continuity counter CCp [fn] of the current filter number fn, the packet number estimation unit 44 determines the current continuity counter CCc value and the current filter. Using the value of the previous continuity counter CCp [fn] of the number fn and the previous packet number PNp [fn] of the current filter number fn, the packet number PNc of the received TS packet is changed to PNp [fn] + (Ccc + 16 -CCp [fn]). Here, “16” is used because the continuity index in the TS packet circulates between “0” to “15”.

  When the value of the error packet number counter of the current filter number exceeds the error allowable threshold, that is, the section switching determination unit 45 acquires the TS packet of the PID corresponding to the current filter number fn last time, When the number of error packets generated until the TS packet is acquired exceeds the error tolerance threshold, it is determined that the section has been switched. When the value of the error packet number counter of the current filter number fn is equal to or smaller than the error allowable threshold, that is, the section switching determination unit 45 obtains the TS packet of the PID corresponding to the current filter number fn last time and acquires the current (latest) TS. When the number of error packets generated until the packet is acquired is equal to or less than the error allowable threshold, the value of the error packet number counter for the filter of the current filter number is set to 0.

  The section switching determining unit 45 determines that the section has been switched when the packet number estimated by the packet number estimating unit 44 is larger than the total number of packets of the current filter number fn and the current section number sn.

  Based on the section length in the received TS packet including the head portion of the section and the size of the TS packet, the packet number calculation unit 46 determines the total number of packets Pnum [fn, sn of the current filter number fn and the current section number sn. ] Is calculated based on the following formula (1).

Pnum [fn, sn] = [(section length + 187) / 184] (1)
However, [a] is the maximum integer not exceeding a.

  The section version determination unit 49 uses the section version in the TS packet (A) including the head portion of the received section and the same section number as the received TS packet (A) temporarily stored in the RAM 35 in an incomplete state. It is determined whether the section version of the TS packet (B) belonging to the section is the same.

  The RAM 36 is for temporarily storing received TS packets. The RAM 36 has a management area for each section. The management area of each section has a storage area for TS packets having packet numbers belonging to the section. The management area for each section has an area for storing the section number and section version of the section.

  When the received TS packet is an unacquired packet, the cache control unit 35 increments the counter of the number of received packets of the current filter number fn and the current section number sn, and the current packet estimated by the packet number estimation unit 44 The received TS packet is stored in the RAM 36 in correspondence with the number PNc. If the TS packet with the current packet number PNc is already temporarily stored in the RAM 36, the counter of the number of received packets is not incremented and is overwritten and saved in the RAM 36.

  When the section version determination unit 48 determines that the section versions are not the same, the cache control unit 35 has the same section number as the section number of the received TS packet that is temporarily stored in the unfinished state from the RAM 35. Delete all TS packets belonging to the section.

  In addition, the cache control unit 35 deletes the TS packets constituting the section read from the RAM 36 by the section reconfiguration unit 47.

  When the section reconfiguration unit 47 acquires all TS packets constituting the section of the current filter number fn and the current section number sn, that is, the TS packet stored in the RAM 36 and the most recently received TS packet When one section can be constructed by reading all the TS packets from the RAM 36, the section is reconstructed from the read TS packets, and the CRC is checked. The section reconfiguration unit 47 outputs the configured section to the section request unit 48 when there is no error as a result of the CRC check.

  The section request unit 48 reconfigures a module from a plurality of sections sent from the section reconfiguration unit 47 and outputs the module to the browser request processing unit 7.

(Operation)
Hereinafter, the section acquisition operation by the digital broadcast receiving apparatus according to the present embodiment will be described.
First, variables used in the description of operations described below will be described. FIG. 4 is a diagram for explaining each variable.

  Referring to FIG. 4, FIL_NUM represents the number of filters in use, that is, the number of PIDs to be filtered. fn represents the current filter number. ERR [fi] represents the value of the PID error packet number counter corresponding to the filter number fi. ERR_THR represents an error tolerance threshold. PNc represents the packet number of the most recently received (ie, current) TS packet. PNp [fi] represents the packet number of the previously received TS packet having the PID corresponding to the filter number fi. CCc indicates the current value of the continuity counter. CCp [fi] indicates the value of the previous continuity counter of the PID corresponding to the filter number fi. sn represents the current section number. Pnum [fi, si] represents the total number of TS packets having a PID corresponding to the filter number fi and belonging to the section number si. Prv [fi, si] represents the total number of received TS packets having a PID corresponding to the filter number fi and belonging to the section number si. SGET [fi] is a flag indicating that section acquisition processing is being executed for a packet having a PID corresponding to the filter number fi.

  FIG. 5 is a flowchart showing a section acquisition procedure by the digital broadcast receiving apparatus according to the present embodiment.

  Referring to FIG. 5, first, error control unit 41 checks the transport error indicator in the received TS packet, and when an error is set in transport error indicator (YES in step S101), all filters are checked. Error packet counter ERR [j] (j = 0 to (FIL_NUM-1)) is incremented (step S102), and the received TS packet is not output to the PID filter unit 21, and the processing for the TS packet is performed. finish.

  On the other hand, when no error is set in the transport error indicator (NO in step S101), the error control unit 41 outputs the received TS packet to the PID filter unit 21.

  The PID filter unit 21 checks the packet identifier (PID) in the received TS packet, and when the PID is not a filtering target PID (NO in step S103), the received TS packet is not output, and the TS packet The process ends.

  In addition, even if the PID is a filtering target PID (YES in step S103), the PID filter unit 21 does not select a section reception target PID, that is, the received TS packet is a video TS packet or an audio TS. When it is a packet (NO in step S104), the received TS packet is sent to the audio decoding processing unit 4 or the video decoding processing unit 5 according to the PID. The audio decoding processing unit 4 and the video decoding processing unit 5 perform non-section reception processing on the received TS packet (step S105).

  On the other hand, when the PID is a filtering target PID (YES in step S103) and the PID is a section reception target PID (YES in step S104), the PID filter unit 21 outputs the PID to the section acquisition unit 30. . The section acquisition control unit 43 in the section acquisition unit 30 sets the filter number corresponding to the PID to the current filter number fn (step S106).

  Next, the section acquisition control unit 43 checks whether the start is set in the bay load unit start indicator in the received TS packet, that is, whether the received TS packet is the first packet including the head part of the section. When the packet is a packet (YES in step S107), the constituent elements in the section acquisition unit 30 are caused to perform the first packet processing described later (step S108). The section acquisition control unit 43 also sets the section acquisition unit when the start is not set in the bay load unit start indicator in the received TS packet, that is, when the received TS packet is not the first packet (NO in step S107). The non-leading packet processing described later is performed on the components within 30 (step S109).

  Next, the cache control unit 35, when the received TS packet is an unacquired packet, that is, the TS packet of the current packet number PNc estimated by the received TS packet (estimation is performed in step S108, details will be described later). Is not yet stored in the RAM 36, the counter Prv [fn, sn] of the number of received packets of the current filter number fn and the current section number sn is incremented (step S111).

  Next, the cache control unit 35 stores the received TS packet in the RAM 36 in association with the current packet number PNc. That is, the cache control unit 35 stores the received TS packet in the area for the current packet number PNc in the management area of the section with the current section number sn in the RAM 36. In this case, even if the TS packet of the current packet number PNc is already temporarily stored in the RAM 36, it is overwritten and saved (step S112).

  When the section reconfiguration unit 47 acquires all TS packets constituting the section of the current filter number fn and the current section number sn (Prv [fn, sn] == Pnum [fn, sn]) (in step S113) YES), the section is reconstructed from the latest received TS packet and the TS packet belonging to that section in the RAM 36, and the CRC is checked.

  If there is no error as a result of the CRC check (YES in step S114), section reconfiguration unit 47 outputs the reconfigured section to section request unit 48. The section request unit 48 reconfigures a module from the plurality of sections sent from the section reconfiguration unit 47 and outputs the module to the browser request processing unit 7 (step S115).

  After step S115 and when NO in step S114, the cache control unit 35 deletes the TS packet constituting the section read from the RAM 36 by the section reconfiguration unit 47 (step S116).

  Next, the section acquisition control unit 43 cancels the setting of the section acquisition flag SGET [fn] for the current filter number fn (SGET [fn] = 0) (step S117).

(Handle packet processing)
FIG. 6 is a flowchart showing the procedure of the leading packet process in step S108.

  Referring to FIG. 6, first, section acquisition control unit 43, when TS packet belonging to the section of the section number in the received TS packet is temporarily stored in RAM 35 in an incomplete state (YES in step S201). The current section number sn is set to the section number in the received TS packet (step S202).

  Next, the section version determination unit 49 determines whether the section version in the received TS packet is the same as the section version of the TS packet belonging to the section having the same section number that is temporarily stored in the RAM 35 in an incomplete state. Determine whether. When the section version determination unit 48 determines that the section versions are not identical (NO in step S203), the cache control unit 35 stores all of the sections belonging to the section having the same section number that are temporarily stored from the RAM 35 in an incomplete state. Are deleted (step S204).

  On the other hand, when the section having the section number in the received TS packet is not temporarily stored in the RAM 35 (NO in step S201), the section acquisition control unit 43 instructs the cache control unit 35 to store the RAM 36. Create a management area for the section. Note that the cache control unit 25 writes the section number (obtained from the received TS packet) and the section version (obtained from the received TS packet) of the section in the management area for the section (step S205).

  Next, the section acquisition control unit 43 sets the current section number sn to the section number in the received TS packet (step S206).

  After step S204 and after step S206, the packet number calculation unit 46 determines the total number of packets Pnum of the current filter number fn and the current section number sn based on the section length in the received TS packet and the size of the TS packet. [Fn, sn] is calculated based on the equation (1).

  Further, the section acquisition control unit 43 initializes the counter Prv [fn, sn] of the number of received packets of the current filter number fn and the current section number sn to 0 (step S207).

  After step S207 and when YES in step S203 (when the section versions are different), the section acquisition control unit 43 receives the value of the previous continuity counter CCp [fn] of the current filter number fn. The section acquisition flag SGET [fn] for the current filter number fn is set to 1 (indicating acquisition), and the previous packet number PNp [fn] for the current filter number fn is set to 0. Initialization is performed to initialize the error packet number counter ERR [fn] of the current filter number fn to 0, and the packet number PNc of the received TS packet is set to 0 (step S208).

(Non-first packet processing)
FIG. 7 is a flowchart showing the procedure of non-leading packet processing in step S109.

  Referring to FIG. 7, first, section acquisition control unit 43, when section acquisition flag SGET [fn] of current filter number fn is not set (SGET [fn] == 0) (NO in step S301). Then, the other component in the section acquisition unit 30 is made to stop the section acquisition process until the TS packet including the head part of the section is acquired.

  When the section acquisition flag SGET [fn] of the current filter number fn is set (SGET [fn] == 1) (YES in step S301), the section acquisition control unit 43 sends a section to the section switching determination unit 45. To determine the switching of.

  When the value of the error packet number counter ERR [fn] of the current filter number fn exceeds the error allowable threshold ERR_THR, the section switching determination unit 45 acquires the TS packet of the PID corresponding to the current filter number fn last time. When the number of error packets that occurred between the acquisition of the current TS packet and the current TS packet exceeds the error tolerance threshold ERR_THR (YES in step S302), it is determined that the section has been switched. When it is determined that the section has been switched, the section acquisition control unit 43 cancels the setting of the section acquisition flag SGET [fn] of the current filter number fn, and the other components in the section acquisition unit 30 Section acquisition processing is stopped until a TS packet including the first part of the packet is acquired (step S303).

  On the other hand, when the value of the error packet number counter ERR [fn] of the current filter number fn is equal to or smaller than the error allowable threshold ERR_THR, the section switching determination unit 45 acquires the TS packet of the PID corresponding to the current filter number fn last time. When the number of error packets generated from the acquisition of the current TS packet to the current allowable error threshold ERR_THR is equal to or less than the error allowable threshold ERR_THR (NO in step S302), the error packet count counter ERR [fn] for the filter of the current filter number fn The value is reset to 0 (step S304).

  Next, the section acquisition control unit 43 sets the current value of the continuity counter CCc to the continuity index in the received TS packet (step S305).

  Next, the packet number estimation unit 44 compares the current continuity counter CCc value with the previous continuity counter CCp [fn] value of the current filter number fn, and the current continuity counter CCc value is determined. When it is larger than the value of the previous continuity counter CCp [fn] of the current filter number fn (YES in step S306), the value of the current continuity counter CCc and the previous continuity counter CCp [fn of the current filter number fn ] And the previous packet number PNp [fn] of the current filter number fn, the packet number PNc of the received TS packet is estimated as PNp [fn] + (Ccc−CCp [fn]) (step S307).

  Further, when the current continuity counter CCc value is less than or equal to the previous continuity counter CCp [fn] of the current filter number fn (NO in step S306), the packet number estimation unit 44 determines the current continuity counter CCc. The packet number PNc of the received TS packet is PNp using the value of, the previous continuity counter CCp [fn] of the current filter number fn, and the previous packet number PNp [fn] of the current filter number fn. [Fn] + (Ccc + 16−CCp [fn]) is estimated (step S308).

  Next, the packet number calculation unit 46 determines whether or not the relationship of (PNc == (PNp [fn] +1) == Pnum [fn, sn]) is established, and when the above relationship is established ( YES in step S309), the total number of packets Pnum [fn, sn] of the current filter number fn and the current section number sn is increased by 1 (step S310). This is a correction process for the fact that the total number of packets calculated in step S207 may be smaller than the actual total number of packets because the TS packet does not consider the case where the adaptation field is included.

  Next, when the estimated packet number is larger than the total number of packets of the current filter number fn and the current section number sn (PNc> Pnum [fn, sn] −1), the section switching determination unit 45 (step S311). YES), it is determined that the section has been switched. When it is determined that the section has been switched, the section acquisition control unit 43 cancels the setting of the section acquisition flag SGET [fn] for the current filter number fn, and sets the head of the section as the other component of the section acquisition unit 30. Section acquisition processing is stopped until a TS packet including a portion is acquired (step S303).

  On the other hand, when the estimated packet number is equal to or smaller than the total number of packets of the current filter number fn and the current section number sn (PNc ≦ Pnum [fn, sn] −1) (NO in step S311). ), It is determined that the section has not been switched. In this case, the section acquisition control unit 43 sets the value of the previous continuity counter CCp [fn] of the current filter number to the value of the current continuity counter CCc, and the previous packet number PNp [fn of the current filter number fn. ] Is set to the estimated packet number PNc (step S312).

  As described above, according to the present embodiment, it is possible to receive a TS packet that does not include information indicating what number of packet in which section, and to reconstruct a section from the TS packet in a short time. it can.

(Modification)
The present invention is not limited to the above embodiment. A modification is illustrated below.

(1) Overwriting to RAM 36 In the embodiment of the present invention, in step S112, the cache control unit 35 stores the received TS packet in the RAM 36 in association with the current packet number PNc. Therefore, even if the TS packet of the current packet number PNc is already temporarily stored in the RAM 36, it is overwritten and saved, but the present invention is not limited to this.

  For example, when the TS packet with the current packet number PNc has already been temporarily stored in the RAM 36, the cache control unit, the content of the received TS packet and the content of the TS packet with the current packet number PNc temporarily stored in the RAM 36. Only when they do not match, the TS packet of the current packet number PNc temporarily stored in the RAM 36 with the received TS packet may be overwritten.

  The cache control unit may not write the received TS packet to the RAM 36 when the TS packet of the current packet number PNc is already temporarily stored in the RAM 36.

(2) Digital broadcast reception program A part of the digital broadcast reception device is arranged such that a CPU, a memory, etc. are arranged so that it can function as a computer, and this computer has a demodulation unit 2 and a TS decode treatment unit 3 (PID included therein) Filter unit 21, error control unit 41, section acquisition control unit 43, section switching determination unit 45, packet number estimation unit 44, packet number calculation unit 46, section version determination unit 49, cache control unit 35, RAM 36, section reconfiguration unit 47, section request unit 48), audio decoding processing unit 4, video decoding processing unit 5, browser request processing unit 7, browser 8 and presentation processing unit 6 are installed as a digital broadcast receiving program in a computer, To execute the digital broadcast reception program It may be.

  In order to install the digital broadcast receiving program in the digital broadcast receiving apparatus, a memory card, CD-ROM, wireless, network, or the like may be used.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a functional block diagram of the digital broadcast receiver which concerns on embodiment of this invention. It is a functional block diagram of TS decoding process part 3 in the digital broadcasting apparatus concerning embodiment of this invention. It is a functional block diagram of the carousel reception processing unit 22 in the digital broadcast apparatus according to the embodiment of the present invention. It is a figure for demonstrating each variable. It is a flowchart which shows the acquisition procedure of the section by the digital broadcast receiver which concerns on embodiment of this invention. It is a flowchart which shows the procedure of the head packet process in step S108. It is a flowchart which shows the procedure of the non-head packet process in step S109. It is a figure which shows the data structure used with a DSM-CC data carousel transmission system. It is a conceptual diagram of the data transmission performed by a DSM-CC data carousel transmission system. It is a figure which shows the detailed structure of a section prescribed | regulated by the MPEG2 Systems (ISO / IEC 13818-1) standard. It is a figure which shows the detailed structure of TS packet prescribed | regulated by MPEG2 Systems (ISO / IEC 13818-1) specification.

Explanation of symbols

  1 tuner, 2 demodulator, 3 TS decode processor, 4 audio decode processor, 5 video decode processor, 6 presentation processor, 7 browser request processor, 8 browser, 9 RAM, 10 CPU, 21 PID filter unit, 22 Carousel reception processing unit, 30 section acquisition unit, 35 cache control unit, 36 RAM, 41 error control unit, 43 section acquisition control unit, 44 packet number estimation unit, 45 section switching determination unit, 46 packet number estimation unit, 47 section Reconfiguration unit, 48 section request unit, 49 section version determination unit.

Claims (1)

A digital broadcast receiver for receiving a digital broadcast in which a section as a transfer unit is repeatedly transmitted,
It means for receiving a transport stream packet,
Storage means for temporarily storing received packets;
A section acquisition unit that reconstructs sections from received packets,
The section acquisition unit
Means for estimating a packet number received packet indicates what number of packets the section,
When the received packet is not stored in the storage means, and hand-stage writing the packet in the storage means,
If you get all the packets belonging to one of the sections includes means for reconstructing the section,
Wherein the means for estimating, when the latest packet received to date does not contain the beginning of the section, the continuity indicators are included continuity index in the latest packet, the last packet received last, and the last packet A digital broadcast receiver that estimates the packet number of the latest packet based on the packet number.

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