JP5566277B2 - Multiple broadcast receiver - Google Patents

Description

  The present invention relates to a multiplex broadcast receiver that receives and reproduces broadcast data in which a plurality of programs are multiplexed.

  2. Description of the Related Art Conventionally, a multiplex broadcast receiver that receives reception data compliant with the MPEG2-TS (Transport Stream) standard is known (see, for example, Patent Document 1). In such a broadcast receiver, two types of error correction processing may be performed on received data. One is Viterbi decoding processing performed for convolutional coding, and the other is Reed-Solomon decoding processing performed for Reed-Solomon coding.

JP 2008-206156 A (page 5-13, FIG. 1-15)

  By the way, in the received data conforming to the MPEG2-TS standard used in the above-mentioned Patent Document 1 and the like, after two kinds of error correction are completed, desired program data is extracted from the multiplexed program data. The program video and audio are played back. In particular, since the Reed-Solomon decoding process performed for error correction is complicated, there is a problem that the processing amount of program reception including this process is large. For this reason, it is necessary to use a DSP having a high processing capacity or to perform parallel processing using a plurality of DSPs, which causes an increase in cost.

  The present invention was created in view of the above points, and an object of the present invention is to provide a multiplex broadcast receiver capable of reducing the amount of program reception processing and reducing the cost.

  In order to solve the above-described problems, a multiplex broadcast receiver according to the present invention is a multiplex broadcast receiver that has a structure conforming to the MPEG2-TS standard and receives data obtained by multiplexing one or more program data. Viterbi decoding processing means for performing Viterbi decoding processing on the received data, received data storage means for storing the received data output from the Viterbi decoding processing means, and received data stored in the received data storage means Among the above, data separating means for separating the program data to be received, Reed-Solomon decoding processing means for performing Reed-Solomon decoding processing on the program data separated by the data separating means, and Reed-Solomon decoding processing means Decode the program data after being processed by the video signal, audio signal, and data as the decoded output signal Some of the-bis signal or and a decoding means for outputting a whole. As a result, the Reed-Solomon decoding process can be performed only for the separated program data to be received, and this process can be omitted for the program data that is not the reception target. It becomes possible.

  The received data output from the above-mentioned Viterbi decoding processing means includes first data for specifying a multiplexed program and second data for specifying one or a plurality of elementary streams constituting each program. Received data read from the received data storage means by the data separation means in which the elementary stream corresponding to the program specified using the first data and the second data is specified. It is desirable to separate the elementary stream from Specifically, the first data described above is a PAT as a transport packet compliant with the MPEG2-TS standard, and the second data is a PMT. The elementary stream is a PES as a transport packet compliant with the MPEG2-TS standard, and the PES after being separated by the data separation means is processed by the Reed-Solomon decoding processing means. As a result, the Reed-Solomon decoding process for the PES of the program that is not the reception target can be omitted, and the processing amount can be greatly reduced in response to the decrease in the number of PESs to be processed.

  Further, PAT analysis means for performing error detection based on the error detection code included in the above-described PAT and analyzing the PAT and identifying the PMT corresponding to the reception target program when the PAT has no error is further provided. It is desirable to provide. When a PAT error is detected based on the error detection code described above, the Reed Solomon decoding processing means performs error correction on the PAT, and uses the PAT after error correction by the PAT analysis means. It is desirable to perform another PAT analysis. With respect to PAT, error correction by Reed-Solomon decoding processing can be performed only for those that require error correction, and both reduction in processing amount and improvement in reception performance by error correction can be achieved.

  In addition, it is desirable to further include a PMT analysis unit that analyzes the PMT described above and creates a PMT information table having packet identification information of the PES specified by the PMT. Further, it is desirable that the PMT analysis means described above performs error detection based on an error detection code included in the PMT before analyzing the PMT, and analyzes the PMT when there is no error in the PMT. Further, when a PMT error is detected based on the above-described error detection code, the PMT is subjected to error correction by the Reed-Solomon decoding processing means, and the PMT after the error correction is used by the PMT analysis means. It is desirable to perform another PMT analysis. Only PMTs that require error correction can be corrected by Reed-Solomon decoding, and both reduction in the amount of processing and improvement in reception quality by error correction can be achieved.

  Further, the PMT analysis means described above sequentially reads transport packets from the reception data storage means to obtain packet identification information, and any one of the packet identification information stored in the PMT information table is obtained. It is desirable that error correction by Reed-Solomon decoding processing means is performed on the PES of the matched packet identification information. As a result, it is possible to perform error correction by Reed-Solomon decoding only for transport packets that are expected to have no error in packet identification information, and the number of transport packets that are subject to error correction. Thus, the processing amount can be reduced.

  Further, the PMT analysis means described above matches the packet identification information of the transport packet read from the received data storage means with any packet identification information stored in the PMT information table corresponding to the PMT of the program to be received. And the Reed-Solomon decoding processing means for the transport packet read from the received data storage means when it does not match the packet identification information stored in the PMT information table corresponding to the PMT of the program not to be received It is desirable to perform error correction by. As a result, when there is a high possibility that there is an error in the transport packet read from the received data storage means, error correction can be performed by the Reed-Solomon decoding process.

  Further, when error correction is performed on the PES by the Reed-Solomon decoding processing unit, the PES further includes a totaling unit that counts the number of error corrections for each packet identification information, and the decoding unit uses the total value by the totaling unit as a reference. When exceeding the value, it is desirable to stop the output of the decoded output signal corresponding to the PES specified by the packet identification information whose sum exceeds the reference value. Specifically, when the above-described decoded output signal is an audio signal, it is desirable that the decoding unit performs a mute process for stopping the output of the audio signal. Thereby, it is possible to prevent the audio output quality from being extremely deteriorated and giving the user unpleasant feeling. Alternatively, when the above-described decoded output signal is a video signal, it is desirable that the decoding unit performs a fade-out process for stopping the output of the video signal. Thereby, it is possible to prevent the quality of the video display from being extremely deteriorated and giving the user an unpleasant feeling.

It is a figure which shows the basic data structure of MPEG2-TS. It is a figure which shows the data structure of PAT. It is a figure which shows the data structure of PMT. It is a figure which shows the rough relationship of PAT, PMT, and each PES by a specific example. It is a figure which shows the structure of the multiplex broadcast receiver of one Embodiment. It is a flowchart which shows the schematic operation | movement procedure of a multiplex broadcasting receiver. It is a flowchart which shows the detailed operation | movement procedure of a PAT search. It is a flowchart which shows the detailed operation | movement procedure of PAT analysis. It is a figure which shows the specific example of a PAT information table. It is a flowchart which shows the operation | movement procedure of the modification of the PAT analysis which added the Reed-Solomon decoding process. It is a figure which shows the specific example of a PMT information table. It is a flowchart which shows the detailed operation | movement procedure of a PES isolation | separation process. It is a flowchart which shows the operation | movement procedure of the modification of the PES isolation | separation process which added the Reed-Solomon decoding process when the acquired PID value and the PID value corresponding to the program which does not want to receive do not match.

  Hereinafter, a multiplex broadcast receiver according to an embodiment to which the present invention is applied will be described with reference to the drawings.

(Data structure of MPEG2-TS)
First, the data structure of MPEG2-TS will be described. FIG. 1 is a diagram showing a basic data structure of MPEG2-TS. As shown in FIG. 1, MPEG2-TS includes a TS header part, a payload part (data body), and an RS part. The TS header part and the payload part constitute a 188-byte transport packet. The RS part is a Reed-Solomon parity word and is used for error correction of the transport packet. The transport stream (TS) is multiplexed and separated by this 188-byte fixed length transport packet.

  Data transmitted in MPEG2-TS includes PAT (Program Association Table), PMT (Program Map Table), CAT (Conditional Access Table), NIT (Network Information Table), and various PES (Packetized Elementary Stream).

  PAT: PID (Packet Identification, packet identification information) of a transport packet transmitting a table (PMT) describing the program configuration is described for each program (program) number. The PID of the PAT itself has a fixed value (0x0000). This PAT is received once within a predetermined time.

  FIG. 2 is a diagram illustrating a data structure of the PAT. As shown in FIG. 2, the PAT includes the network ID (PID) of each PMT so that the PID of each PMT can be known. In addition, a CRC (Cyclic Redundancy Check) 32 that is an error detection code is included at the end of the PAT.

  PMT: In the payload portion of this transport packet, a list of PIDs and associated information of a transport packet in which individual streams such as video and audio constituting one program are transmitted are described.

  FIG. 3 is a diagram illustrating a data structure of the PMT. In this, the stream type indicates the type of PES (audio, video, etc.), the elementary PID indicates the PID of the PES, and the ES information length indicates the byte length of the subsequent descriptor. CRC32 is included at the end of the PMT.

  CAT: The CA of the program (information related to limited reception / scramble) is described in the payload portion of this transport packet. From this CAT, it is possible to know the PID including the actual decryption / decryption permission information and obtain the scrambled decryption information.

  NIT: Broadcast station network information of the program is described in the payload portion of this transport packet.

  Various PES: Various audio, video, and service data are stored in packets. This PES is an abbreviation for the acronym of packetized elementary streams, which means each of encoded video, audio, and data services.

  FIG. 4 is a diagram showing a schematic relationship between PAT, PMT, and each PES as a specific example. In the example shown in FIG. 4, PMT-1 and PMT-2 of two programs are specified by PAT. One PMT-1 identifies one video PES, one audio PES, and one data PES. The other PMT-2 identifies one video PES and two audio PESs.

  Conventionally, when program data including such two programs is received, error correction is performed by Viterbi decoding processing and Reed-Solomon decoding processing to obtain correct received data, and then any one of the received data is included. The video programs and audio signals were obtained by separating the PES and decoding various PES.

  On the other hand, in the present invention, PAT and PMT are extracted at the stage when the Viterbi decoding process is completed, various PES corresponding to the program (PMT) to be received is specified, and Reed-Solomon decoding is performed on the specified various PES. To implement. As a result, the Reed-Solomon decoding process for various PESs corresponding to programs (PMTs) that are not desired to be reproduced is omitted, and the processing amount can be greatly reduced.

(Configuration of multiplex broadcast receiver)
Next, the configuration of the multiplex broadcast receiver according to one embodiment will be described. FIG. 5 is a diagram illustrating a configuration of the multiplex broadcast receiver 100 according to an embodiment. As shown in FIG. 5, the multiplex broadcast receiver 100 of this embodiment includes an RF tuner unit 10, a channel decoder unit 20, a source decoder unit 30, and a main control unit 60. For example, the multiplex broadcast receiver 100 receives broadcast data multiplexed by a DMB (Digital Multimedia Broadcast) method.

  The RF tuner unit 10 extracts a desired reception frequency (tuning frequency) component from a signal received via an antenna, and outputs an intermediate frequency signal obtained by performing frequency conversion on the extracted signal.

  The channel decoder unit 20 constitutes a front end unit, and includes an OFDM (Orthogonal Frequency Division Multiplex) receiving unit 22 and a Viterbi decoder 24. The OFDM receiver 22 removes the protection period from the received OFDM symbol, and then performs a fast demodulation to perform a predetermined demodulation operation. The Viterbi decoder 24 performs error correction by performing Viterbi decoding processing on the signal demodulated by the OFDM receiver 22, and outputs received data after error correction.

  The source decoder unit 30 constitutes a back end unit, and includes an input buffer 32, a demultiplexer 34, RS (Reed Solomon) decoders 36 and 38, a video buffer 40, a video decoder 42, an audio buffer 44, an audio decoder 46, A data buffer 48, a data service decoder 50, an STC (System Time Clock) generator 52, and a controller 54 are provided.

  The input buffer 32 holds reception data output from the Viterbi decoder 24 in the channel decoder unit 20. The demultiplexer 34 separates and outputs a transport packet having a designated PID value from the stream read from the input buffer 32. The RS decoder 36 performs error correction by Reed-Solomon decoding processing on the PAT and PMT acquired from the input buffer 32. The RS decoder 38 performs error correction on the PES or the like separated by the demultiplexer 34 by Reed-Solomon decoding processing.

  The video buffer 40 temporarily holds PES packetized video data. The video decoder 42 reads the video data held in the video buffer 40, performs predetermined demodulation processing (for example, processing such as recommendation H.246), and outputs a video signal. The audio buffer 44 temporarily holds PES packetized audio data. The audio decoder 46 reads the audio data held in the audio buffer 44, performs predetermined demodulation processing (for example, demodulation processing such as AAC (Advanced Audio Coding)), and outputs an audio signal. The data buffer 48 temporarily holds PES packetized data service data. The data service decoder 50 reads the data held in the data buffer 50 and performs a predetermined demodulation process.

  The STC generation unit 52 outputs an STC that is a time reference based on an SCR (System Clock Reference) included in the transport stream. Based on the PTS (Presentation Time Stamp) and DTS (Decoding Time Stamp) included in the transport packet and the STC output from the STC generation unit 52, the control unit 54 performs a video decoder 42, an audio decoder 46, and a data service decoder. 50 is controlled. The main control unit 60 controls the entire multiplex broadcast receiver 100.

  The Viterbi decoder 24 described above is Viterbi decoding processing means, the input buffer 32 is received data storage means, the demultiplexer 34 is data separation means, the RS decoders 36 and 38 are Reed-Solomon decoding processing means, the video decoder 42, The audio decoder 46 and the data service decoder 50 correspond to decoding means, and the main control unit 60 corresponds to PAT analysis means, PMT analysis means, and aggregation means.

(Operation of multiplex broadcast receiver)
Next, in the multiplex broadcast receiver 100 according to the present embodiment, the operation from the reception data stored in the input buffer 32 until the various PESs corresponding to the desired program are separated and stored in the video buffer 40 or the like will be described. To do.

  FIG. 6 is a flowchart showing a schematic operation procedure of the multiplex broadcast receiver 100. First, the main control unit 60 searches for PAT from the received data stored in the input buffer 32 (step 100), and determines whether or not a PAT exists (step 102). If not, a negative determination is made and the process ends.

  If there is a PAT, an affirmative determination is made in step 102. Next, the main control unit 60 analyzes the PAT, and acquires the number of programs broadcast by the broadcast station and the PID value of the PMT in which the information of each program is stored based on the obtained PAT information ( Step 104).

  Next, the main control unit 60 determines whether or not one or more PMTs are included based on the analysis result of step 104 (step 105). If not included, a negative determination is made and the process ends.

  If one or more PMTs are included, an affirmative determination is made in the determination in step 105. Next, the main control unit 60 searches the received data stored in the input buffer 32 for the PMT specified by the PID value acquired by the PAT analysis (step 106), and determines whether there is a PMT. (Step 108). A negative determination is made until a PMT is found, and the PMT search in step 106 is repeated.

  If a PMT is found, an affirmative determination is made in step 108. Next, the main control unit 60 analyzes the PMT and acquires information such as PES constituting one program (step 110). Further, the main control unit 60 determines whether or not this PMT is the last PMT (step 112). If there is another PMT, the main control unit 60 makes a negative determination and returns to step 106 to search for the PMT. Is repeated.

  If the analyzed PMT is the last PMT, an affirmative determination is made in step 112. Next, the main control unit 60 determines a program (PMT) to be received (step 114) and separates the PES corresponding to the PMT by the demultiplexer 34 (step 116). The program to be received is determined based on a user instruction using an operation unit (not shown).

(PAT search operation)
Next, details of the PAT search operation in step 100 of FIG. 6 will be described. FIG. 7 is a flowchart showing a detailed operation procedure of the PAT search. First, the main control unit 60 determines whether there is received data in the input buffer 32 (step 200). If there is no received data, a negative determination is made, and the main control unit 60 sets the PAT flag indicating the presence or absence of PAT to OFF (step 202).

  If there is received data in the input buffer 32, an affirmative determination is made in step 200. Next, the main control unit 60 acquires one transport packet from the input buffer 32 (step 204), acquires a PID value from this packet (step 206), and the acquired PID value corresponds to the PAT. It is determined whether or not it matches the unique value (0x0000) (step 208). If they do not match, a negative determination is made, and the same processing is performed by returning to step 200 for the other transport packets.

  If the acquired PID value matches the above unique value, an affirmative determination is made in the determination in step 208, and the main control unit 60 stores the transport packet (PAT) acquired in step 204 in the memory ( (Step 210) and the PAT flag is set to ON (step 212).

(PAT analysis operation)
Next, the details of the PMT analysis operation in step 104 of FIG. FIG. 8 is a flowchart showing a detailed operation procedure of PAT analysis. First, the main control unit 60 determines whether or not the PAT flag is set to ON (step 300). When the PAT flag is set to OFF (when there is no PAT), a negative determination is made, and the process ends.

  If the PAT flag is set to ON, an affirmative determination is made in the determination of step 300. Next, the main control unit 60 obtains the CRC32 value included in the PAT transport packet stored in the memory (step 302), and the PAT transport packet (CRC32) stored in the memory. CRC32 is calculated using the portion excluding (step 304). Then, the main control unit 60 determines whether or not the acquired CRC32 value matches the CRC32 value obtained by the calculation (step 306). If not, a negative determination is made, and then the main control unit 60 sets the PAT analysis OK flag to OFF (step 308).

  If both CRC32 values match, an affirmative determination is made in step 306. Next, the main control unit 60 analyzes the contents of the PAT (step 310). In this analysis process, the PID values of the PMT corresponding to each program are acquired, and a PAT information table including these PID values is created. Thereafter, the main control unit 60 sets the PAT analysis OK flag to ON (step 312).

  FIG. 9 is a diagram showing a specific example of the PAT information table. As shown in FIG. 9, “PID value” and “content” are stored in the PAT information table in the order of acquisition of PID values. Here, the contents are for distinguishing PMTs of different programs from each other. In the example shown in FIG. 9, “PMT-1” and “PMT-2” are stored.

  By the way, in the above description, when the CRC 32 does not match in the determination of step 306 (when a negative determination is made), the PAT analysis processing of step 310 is not performed, but the portion other than the CRC 32 of the received PAT is not The PAT analysis process in step 310 may be performed as correct.

  Alternatively, in this embodiment, since the Reed-Solomon decoding process is not performed at this time, there is a possibility that the erroneous content of the PAT is corrected to the correct content by performing this process. For this reason, it is desirable to perform the Reed-Solomon decoding process when the acquired CRC32 value and the CRC32 value obtained by the calculation do not match in the determination in step 306 (when a negative determination is made).

  FIG. 10 is a flowchart showing an operation procedure of a modified example of the PAT analysis to which the Reed-Solomon decoding process is added. In the operation procedure shown in FIG. 10, steps 320 to 326 are added to the operation procedure shown in FIG. 8, and each of the added steps will be described below.

  If the acquired CRC32 value does not match the calculated CRC32 value, a negative determination is made in step 306. Next, the main control unit 60 sends an instruction to the RS decoder 36, performs Reed-Solomon decoding processing on the PAT transport packet stored in the memory, and corrects the error (step 320). The corrected transport packet (PAT) is again stored in the memory. Next, the main control unit 60 obtains the CRC32 value included in the PAT transport packet after error correction stored in the memory (step 322), and the PAT transport packet after error correction. CRC32 is calculated using (the part excluding CRC32) (step 324). Then, the main control unit 60 determines whether or not the acquired CRC32 value matches the CRC32 value obtained by the calculation (step 326). If they do not match, a negative determination is made, the process proceeds to step 308, and the PAT analysis OK flag is set to OFF. If both CRC32 values match, an affirmative determination is made in step 326. The process proceeds to step 310 where the PAT content analysis is performed.

  In the above description, if the CRC 32 does not match in the determination in step 326 (when a negative determination is made), the PAT analysis processing in step 310 is not performed, but the portion other than the CRC 32 of the received PAT is not The PAT analysis process in step 310 may be performed as correct.

(Separation of PES of received program)
Next, the details of the PES separation operation in step 116 of FIG. 6 will be described. In the PMT analysis operation in step 110 of FIG. 6, information on PESs constituting each program (PMT) is acquired, and a PMT information table is created for each program. This PMT information table shows PID values and contents of PES corresponding to each program. FIG. 11 is a diagram illustrating a specific example of the PMT information table. As shown in FIG. 11, “PID value” and “content” are stored in the PMT information table in the order of acquisition of PID values. Here, the contents indicate one of audio (Audio), video (Video), and data service (Data Service). In the example shown in FIG. 11, the audio, video, and data services are provided in each of the three PESs. Stored. The example shown in FIG. 11 corresponds to the case where PMT-1 is selected in the data configuration shown in FIG.

  FIG. 12 is a flowchart showing a detailed operation procedure of the PES separation process. First, the main control unit 60 determines whether there is received data in the input buffer 32 (step 400). If there is no received data, a negative determination is made and the process ends.

  If there is received data in the input buffer 32, an affirmative determination is made in step 400. Next, the main control unit 60 acquires one transport packet from the input buffer 32 (step 402), and further acquires the PID value therein (step 404), and then the acquired PID value is received by the received program. It is determined whether or not it matches any of the PID values stored in the PMT information table (FIG. 11) corresponding to (step 406). If they do not match, a negative determination is made, and the same processing is performed by returning to step 400 for the other transport packets.

  If the PID values match, an affirmative determination is made in step 406. Next, the main control unit 60 sends an instruction to the RS decoder 38 and performs a Reed-Solomon decoding process on the transport packet (PES) having the same PID value output from the demultiplexer 34 ( Step 408). Thereafter, it is determined whether the content of the PES is video (step 410), audio (step 412), and data service (step 414). The data is stored in the corresponding buffer (one of the video buffer 40, the audio buffer 44, and the data buffer 48) (steps 416, 418, and 420). Thereafter, with respect to other transport packets, the process returns to step 400 and the same processing is performed.

  By the way, in this embodiment, since the Reed-Solomon decoding process is not performed on the PMT at this time, the PID value of the PES that should originally be included in the PMT information table of the program desired to be received is erroneously changed. It may have been done. For this reason, when the PID value of the transport packet acquired from the input buffer 32 is not included in the PMT information table of the received program or the PMT information table of the other program that does not want to be received, There is a possibility that the PID value of this transport packet has been changed by mistake. Therefore, it is desirable to perform a Reed-Solomon decoding process on such transport packets to check again whether the PID values match.

  FIG. 13 is a modified example of the PES separation process in which the Reed-Solomon decoding process is added when the PID value of the acquired transport packet does not match the PID value in the PMT information table corresponding to the program that is not desired to be received. It is a flowchart which shows an operation | movement procedure. In the operation procedure shown in FIG. 13, steps 430 to 434 are added to the operation procedure shown in FIG. 12, and each of these added steps will be described below.

  If the acquired PID value does not match any PID value stored in the PMT information table corresponding to the received program, a negative determination is made in the determination of step 406. Next, the main control unit 60 determines whether any PID value in the PMT information table corresponding to a program that is not desired to be received other than the received program matches the PID value acquired in step 404. (Step 430). If they match, an affirmative determination is made, and the same processing is performed by returning to step 400 for the other transport packets.

  If no match is found, a negative determination is made in step 430. Next, the main control unit 60 performs Reed-Solomon decoding processing on the transport packet (PES) acquired in Step 402 (Step 432), and then performs error correction by this Reed-Solomon decoding processing. It is determined whether or not the PID value of the transport packet matches any PID value stored in the PMT information table corresponding to the received program (step 434). If they do not match, a negative determination is made, and the same processing is performed by returning to step 400 for the other transport packets. If they match, an affirmative determination is made in the determination in step 434, and the process proceeds to the PES content determination operation in step 410 or the like. In this way, it is possible to perform error correction by Reed-Solomon decoding processing only for transport packets that are expected to have no error in the PID value. The amount of processing can be reduced by reducing the number of packets.

  As described above, in the multiplex broadcast receiver 100 of the present embodiment that has a structure compliant with the MPEG2-TS standard and receives data in which one or more program data is multiplexed, the separated program data to be received is received. Since the Reed-Solomon decoding process can be performed only on the program data and this process can be omitted for program data that is not a reception target, the processing amount can be greatly reduced.

  In addition, it is possible to perform error correction by Reed-Solomon decoding processing only for PAT that requires error correction, and it is possible to achieve both reduction in processing amount and improvement in reception quality by error correction. Furthermore, error correction by Reed-Solomon decoding processing can be performed only for PMTs that require error correction, and both reduction in processing amount and improvement in reception quality by error correction can be achieved.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. In the embodiment described above, error detection by the CRC 32 is performed before the PMT analysis in step 110 of FIG. 6. If no error is detected, the PMT analysis is performed. If an error is detected, the PMT is analyzed. On the other hand, PMT analysis may be performed after performing Reed-Solomon decoding processing and error correction.

  In the above-described embodiment, the PID value of the transport packet acquired from the input buffer 32 is compared with each PID value of the PMT information table of the received program in the PES separation process shown in FIG. Before that, PID values of all transport packets in the input buffer 32 are acquired, and all of them (both received programs and programs not desired to be received) are not included in the PID values of the PMT information table. If there is, the Reed-Solomon decoding process may be performed on this transport packet. As a result, it is possible to first perform error correction by the Reed-Solomon decoding process for a transport packet that is likely to have an error.

  In the above-described embodiment, the Reed-Solomon decoding process is performed only on the PES of the received program in Step 408 of FIG. 12. In this process, the number of error corrections is set for each PID value unit. You may make it total by. As a counting method, there are a case where an average value is calculated for the latest several times, and a case where a maximum value is extracted among the latest several times. If the number of error corrections increases, the greater the number of error corrections, the worse the radio wave condition of the broadcast wave. If the number of error corrections exceeds a predetermined reference value, sound skipping occurs in the case of audio. The possibility increases, and in the case of video, the possibility that the image is disturbed increases. Therefore, for example, when the total value of the number of error corrections for each PID value exceeds a predetermined reference value set for each PID value, the decoded output signal is stopped. In the case of video, a fade-out process (a process for darkening the screen) may be performed. As a result, it is possible to prevent the user from feeling uncomfortable due to extremely deteriorated audio output and video display quality.

  In the above-described embodiment, the order of acquiring the transport packets from the input buffer 32 in step 400 shown in FIG. 12 is not particularly described. For example, the acquired transport packets are assigned to each PID value. Sorting may be performed for each acquisition, and the acquisition operation and the Reed-Solomon decoding process may be performed in parallel for each PID value. As a result, it is possible to increase the processing speed.

  As described above, according to the present invention, the Reed-Solomon decoding process can be performed only on the separated program data to be received, and this process can be omitted for program data that is not the reception target. The amount of processing can be greatly reduced.

DESCRIPTION OF SYMBOLS 10 RF tuner part 20 Channel decoder part 22 OFDM receiving part 24 Viterbi decoder 30 Source decoder part 32 Input buffer 34 Demultiplexer 36, 38 RS decoder 40 Video buffer 42 Video decoder 44 Audio buffer 46 Audio decoder 48 Data buffer 50 Data service decoder 52 STC generation unit 54 control unit 60 main control unit 100 multiplex broadcast receiver

Claims (14)

A multiplex broadcast receiver having a structure compliant with the MPEG2-TS standard and receiving data obtained by multiplexing one or more program data,
Viterbi decoding processing means for performing Viterbi decoding processing on received data;
Received data storage means for storing received data output from the Viterbi decoding processing means;
Data separating means for separating the program data to be received from the received data stored in the received data storage means;
Reed-Solomon decoding processing means for performing Reed-Solomon decoding processing on program data separated by the data separation means;
Decoding means for performing decoding processing on the program data processed by the Reed-Solomon decoding processing means and outputting a video signal, an audio signal, or a data service signal as a decoded output signal, or a part thereof;
A multiplex broadcast receiver comprising: In claim 1,
The reception data output from the Viterbi decoding processing means includes first data for specifying a multiplexed program and second data for specifying one or a plurality of elementary streams constituting each program. Included,
An elementary stream corresponding to the program specified using the first data and the second data is specified, and the elementary data is read from the received data read from the received data storage means by the data separation means. A multiplex broadcast receiver characterized in that a stream is separated. In claim 2,
The multiplex broadcast receiver according to claim 1, wherein the first data is a PAT as a transport packet conforming to the MPEG2-TS standard, and the second data is a PMT. In claim 3,
The elementary stream is a PES as a transport packet compliant with the MPEG2-TS standard, and the processing by the Reed-Solomon decoding processing unit is performed on the PES after being separated by the data separation unit. A multiplex broadcast receiver. In claim 4,
PAT analysis means for performing error detection based on an error detection code included in the PAT and analyzing the PAT and specifying the PMT corresponding to the program to be received when there is no error in the PAT is further provided. A multiplex broadcast receiver. In claim 5,
When an error in the PAT is detected based on the error detection code, error correction is performed on the PAT by the Reed-Solomon decoding processing unit, and the PAT analysis unit uses the PAT after the error correction. The multiplex broadcast receiver, wherein the PAT analysis is performed again. In any one of Claims 4-6,
A multiplex broadcast receiver further comprising PMT analysis means for analyzing the PMT and creating a PMT information table having packet identification information of the PES specified by the PMT. In claim 7,
The PMT analysis means performs error detection based on an error detection code included in the PMT before analyzing the PMT, and analyzes the PMT when there is no error in the PMT. Broadcast receiver. In claim 8,
When an error of the PMT is detected based on the error detection code, error correction is performed on the PMT by the Reed-Solomon decoding processing means, and the PMT analysis means is used by using the PMT after error correction. A multiplex broadcast receiver characterized in that the PMT is analyzed again. In any one of Claims 7-9,
The PMT analysis means sequentially reads transport packets from the received data storage means to obtain packet identification information, and the acquired packet identification information is stored in any one of the packet identification information stored in the PMT information table. A multiplex broadcast receiver, wherein when the packet matches, the PES of the matched packet identification information is subjected to error correction by the Reed-Solomon decoding processing means. In claim 10,
The PMT analysis means matches the packet identification information of the transport packet read from the received data storage means with any packet identification information stored in the PMT information table corresponding to the PMT of the program to be received. And the Reed-Solomon decoding for the transport packet read from the received data storage means when it does not match the packet identification information stored in the PMT information table corresponding to the PMT of the program not to be received A multiplex broadcast receiver, wherein error correction is performed by a processing means. In any one of Claims 4-11,
When error correction is performed on the PES by the Reed-Solomon decoding processing unit, the PES further includes a counting unit that counts the number of error corrections for each packet identification information,
The decoding means stops output of the decoded output signal corresponding to the PES specified by the packet identification information whose total value exceeds the reference value when the total value by the totaling means exceeds the reference value. A multiplex broadcast receiver. In claim 12,
The multiplex broadcast receiver characterized in that, when the decoded output signal is an audio signal, the decoding means performs a mute process for stopping the output of the audio signal. In claim 12,
The multiplex broadcast receiver, wherein when the decoded output signal is a video signal, the decoding means performs a fade-out process for stopping the output of the video signal.

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