JP4035743B2 - Multiplexer, multiplexed transmission system, and multiplexed transmission method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multiplexing device, a multiplexing transmission system, and a multiplexing transmission method, and can be applied to, for example, a digital satellite broadcasting system. In the present invention, by switching the operation based only on the start time of the schedule data, for example, even when the transmission of the schedule data is stopped by the host control device that controls the operation of the multiplexing device, various programs are viewed. To be able to.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a digital satellite broadcasting system, program specification information PSI (Program Specific Information), which is a service selection criterion, is broadcast at a constant period so that a desired channel can be easily selected from a large number of channels. Yes.
[0003]
FIG. 5 is a block diagram showing this type of digital satellite broadcasting system, which provides various services from the ground station 1. That is, in the ground station 1, the AV server 2 is connected to a broadcast program management device (PGS: Program Guide System) 4 via the main bus BUS, and video data and audio are recorded according to program information managed by the broadcast program management device 4. Send data. Similarly, the data server 3 is connected to the broadcast program management device 4 via the main bus BUS, and transmits various data according to the program information managed by the broadcast program management device 4. Here, these data are receiving station maintenance data and the like.
[0004]
The chains 4A to 4N are configured almost the same, and after the video data, audio data, and various data are encoded by an encoding process suitable for broadcasting, the multiplexed data is generated by time division multiplexing processing. . Further, the multiplexed data is modulated by QPSK (Quadrature Phase Shift Keying) and output.
[0005]
That is, for example, in the chain 4A, the encoders 5A to 5N respectively receive video data and audio data from the AV server 2, and encode these video data and audio data according to an encoding method defined in MPEG (Moving Picture Experts Group). And output. At this time, the encoders 5A to 5N output encoded data D5A to D5N that are encoding processing results by encoding control according to control data output from an encoder control device (ECS: Encoder Control Subsystem) 6, respectively.
[0006]
The encoder control device 6 controls the operations of the encoders 5A to 5N according to the program information recorded in the broadcast program management device 4. The control devices 7A to 7N receive various data from the data server 3, and encode these data by the built-in encoders 8A to 8N according to the program information recorded in the broadcast program management device 4, and obtain the encoded data D8A to D8N. Output.
[0007]
A multiplexing control device (MCS: Multiplexer Control Subsystem) 9 issues control commands and schedule information to the multiplexing device 10 according to the program information recorded in the broadcast program management device 4, and the multiplexing device 10 Accordingly, the output data D5A to D5N and D8A to D8N of the encoders 5A to 5N and encoders 8A to 8N are time-division multiplexed to generate multiplexed data D9. At this time, the multiplexing apparatus 10 scrambles and outputs the multiplexed data D9 as necessary.
[0008]
That is, the multiplexing apparatus 10 delimits video data, audio data, etc. D5A to D5N, D8A to D8N (FIG. 6A) (FIG. 6A) output by predetermined encoders 5A to 5N and 8A to 8N, and converts the data A port stream packet (TS (Transport Stream) packet) is generated (FIGS. 6B and 6C). Further, the transport stream packet is multiplexed (FIG. 6D), and multiplexed data D9 of 30 [Mbps] is generated. Here, 30 [Mbps] is the capacity per repeater of the satellite E.
[0009]
The video data, audio data, and the like multiplexed by the multiplexer 10 are input to the multiplexer 10 with a packet ID assigned to each packet in advance, and the video data assigned to each packet by this packet ID. Audio data etc. can be identified. Multiplexer 10 interpolates a packet based on program specification information PSI at a predetermined cycle in multiplexed data D9 so that a desired channel can be selected based on this packet ID. In addition to these packets, the multiplexing apparatus 10 multiplexes and transmits an electronic program guide (EPG) packet, a scramble key common information (EMM: Entitlement Management Message) packet, and the like.
[0010]
Here, the program specification information PSI is data of selection criteria for selecting a channel based on video data and audio data, and includes PAT (Program Association Table), PMT (Program Map Table), CAT (Conditional Access Table), NIT (Network Information). Table) and four descriptors. Among these, the PAT describes, for example, a PMT packet ID and a NIT packet ID corresponding to a broadcast program channel number (in this case, matches a service ID (SID)), and the PMT constitutes each program. Packet IDs such as video data and audio data are described.
[0011]
Thus, the program specification information PSI detects the PMT packet ID from the PAT, detects the PMT, and then detects the packet ID corresponding to the channel number of the desired program from the PAT, thereby detecting the video data of the desired program. The packet ID to which the audio data is assigned can be easily detected.
[0012]
On the other hand, CAT is an identification index for pay broadcasting (CA system). The NIT records the transponder frequency and the like, which are physical information related to the transmission path. As a result, when the program desired by the user is not broadcast by the currently receiving transponder, the program specification information PSI can receive a desired program by receiving a broadcast by another transponder based on this NIT. Has been made.
[0013]
Thus, the multiplexing apparatus 10 generates a transport stream according to the schedule data output from the multiplexing control apparatus 9 and also generates and outputs program specification information PSI.
[0014]
That is, as shown in FIG. 7, in the multiplexing device 10, the central processing unit (CPU) 11 acquires schedule data from the multiplexing control device 9. Here, conventionally, the schedule data is given by the start time, the duration, and the contents of the program specification information PSI. The central processing unit 11 sets a table necessary for forming a packet of the program specification information PSI in the PSI generator 12 according to the contents of the program specification information PSI recorded in the schedule data.
[0015]
Further, the central processing unit 11 instructs the multiplexing unit 13 to start the operation when the multiplexing start time is reached, and sequentially multiplexes the input data D5A to D5N and D8A to D8N that are sequentially input and outputs the multiplexed data D9. To do. At this time, the central processing unit 11 instructs the PSI generation unit 12 to transmit the program specification information PSI at a set cycle, for example, in the range of 100 [msec] to 1 [sec] with reference to the built-in timer. Then, the multiplexing unit 13 performs multiplexing processing, thereby creating a packet based on the program specification information PSI and performing time division multiplexing. Further, the time elapsed from the start of transmission is monitored by this timer, and when the duration has passed, transmission of the packet by the program specification information PSI is stopped, and transmission of the packet by the program specification information PSI is started as necessary. Further, when the central processing unit 11 outputs different program specification information PSI, the version information of the program specification information PSI is stepped out and output so that a change in the program specification information PSI can be easily detected on the receiving side. To.
[0016]
The modulator 15 (FIG. 5) performs processing such as adding an error correction code to the multiplexed data D9 generated in this way, and then performs QPSK modulation and outputs the result. The ground station 1 frequency-multiplexes this modulated signal and uplinks it from the antenna 16. The digital satellite broadcasting system downlinks the broadcast wave transmitted from the ground station 1 by the satellite E, and receives the broadcast wave transmitted from the satellite E by the antenna 17 at home, etc., and receives an IRD (Integrated Receiver Decoder). ) 18 to demodulate.
[0017]
FIG. 8 is a block diagram showing the IRD. In the IRD 18, the frequency converter 21 converts the frequency of the broadcast wave obtained from the antenna 17 and outputs it. The front end unit 22 selectively processes a broadcast wave by a desired transponder from the output signal of the frequency converter 21, and demodulates and outputs the multiplexed stream transmitted by the transponder.
[0018]
That is, in the front end unit 22, the carrier selection unit 23 switches the local oscillation frequency under the control of the host processor 24, selects a broadcast wave by a desired transponder from the output signal of the frequency converter 21, and intermediates the selected broadcast wave. Convert to frequency signal and output.
[0019]
The QPSK demodulator 25 detects the intermediate frequency signal output from the carrier selector 23 and outputs a multiplexed stream to which an error correction code is added. The FEC decoder 26 performs error correction processing (FEC: Forward Error Correction) on the output data of the QPSK demodulator 25, thereby outputting a multiplexed stream.
[0020]
The transport unit 27 descrambles the multiplexed stream as necessary under the control of the host processor 24, selects a desired packet, and demodulates the multiplexed stream into the original data string. That is, in the transport unit 27, the descrambling circuit 28 outputs the multiplexed stream output from the front end unit 22 to the subsequent demultiplexer 29. At this time, the host processor 24 controls the multiplexed stream to descramble processing. And output.
[0021]
The demultiplexer 29 selects a transport stream packet having a packet ID designated by the host processor 24, and outputs the selected transport stream packet based on the original data string. At this time, the demultiplexer 29 notifies the host processor 24 of the information of the packet with the packet ID value 0 because the PAT is assigned in the program specification information PSI. Similarly, the host processor 24 obtains the PID of the MPEG data by tracing the packet sequentially by the same operation using the PID described in the PAT. Also, common key information for scramble processing is assigned and a packet is detected, and information of this packet is notified to the host processor 24. The demultiplexer 29 determines the attribute of the data assigned to each packet with reference to the stream ID added to each packet together with the packet ID, and outputs it to the subsequent decoder 30.
[0022]
The decoder 30 processes the output data of the transport unit 27 and outputs a video signal SV and an audio signal SA. That is, in the decoder 30, the EPG processor 31 receives data assigned to the packet of the electronic program guide from the transport unit 27, notifies this data to the host processor 24, and controls the host processor 24 to control the image from this data. Generate data. Here, this image data generates a display screen for displaying the contents of the electronic program guide. The EPG processor 31 outputs this image data to the NTSC encoder 32.
[0023]
The video decoder 33 receives video data from the demultiplexer 29, decodes this video data, and outputs it to the NTSC encoder 32. The audio decoder 34 receives the audio data from the demultiplexer 29, decodes this audio data, and outputs it. The NTSC encoder 32 synthesizes the image data output from the EPG processor 31 and the video data output from the video decoder 33 under the control of the host processor 24 and outputs an NTSC video signal SV. A digital / analog conversion circuit (D / A) 35 performs digital / analog conversion processing on the audio data output from the audio decoder 34 and outputs an audio signal SA.
[0024]
The IC card 36 records data related to the reception contract, updates the contents under the control of the host processor 24, and outputs the recorded contents to the host processor 24.
[0025]
The host processor 24 is composed of a computer that controls the operation of the IRD 18 and issues a control command to the carrier selection unit 23 in response to an operation of an operator (not shown) or a remote commander to select a broadcast wave by a desired transponder. Receive automatically. Further, the host processor 24 receives the program specification information PSI output from the demultiplexer 29, holds the PAT, PMT, CAT, and NIT in the built-in memory, and holds this when the version of the program specification information PSI is updated. The contents are updated by the program specification information PSI output from the demultiplexer 29.
[0026]
The host processor 24 issues a control command to the NTSC encoder 32 in response to a user operation, thereby displaying electronic program information on the screen and switching the display. Further, the host processor 24 searches the PMT from the PAT stored in the built-in memory according to the user's selection operation in this on-screen display or according to the channel number input by operating the operation element. The NIT is searched according to the search result, and a control command is issued to the carrier selection unit 23 and the demultiplexer 29 based on the search result. As a result, the host processor 24 switches the packet selected by the demultiplexer 29 and switches the transponder to receive so as to select the program of the channel desired by the user.
[0027]
When receiving a channel in which conditional access is not permitted for receiving a desired channel in this way, the host processor 24 reads data relating to conditional access recorded in the IC card 36. Further, when the channel currently being received by this data is a channel for which a reception contract is made, the host processor 24 processes the CAT based on the data recorded in the IC card 36, and the descrambling circuit 28 based on the processing result. Instructs the descrambling process. If charging is required at this time, the host processor 24 notifies a predetermined processing center via a telephone line, for example.
[0028]
[Problems to be solved by the invention]
By the way, when a desired program is viewed by selectively processing the transport stream on the basis of the packet ID in this way, the program specification information PSI added by the multiplexer 9 in accordance with the change of the program to be transmitted or the like. Will need to be updated.
[0029]
That is, as shown in FIG. 9, for example, “broadcast the program with the second audio until 12: 5, then pause the broadcast, and stop the second audio from 12:10 and restart the broadcast” In this case, until 12: 5, the program specification information PSI with the content “second audio is present” is transmitted, and from 12: 5, the program specification information PSI with the content indicating that the broadcast is suspended is transmitted. Furthermore, from 12:10, it is necessary to switch to the program specification information PSI with the content “no second audio”. If the transmission of MPEG data is stopped at 12: 5 and then started at 12:10, the multiplexing schedule needs to be transmitted again.
[0030]
That is, in this case, the multiplexing control device 9 changes the contents of the program specification information PSI, “there is a second voice”, for 5 minutes from 12:00, and continues for 5 minutes from 12:00 as the start time. It is necessary to send schedule data to the multiplexing apparatus 10 so as to send it.
[0031]
However, when the transmission stop time is designated by the duration time in this way, for example, due to an accident or the like in a higher-level control device that controls the operation of the multiplexing device 10, such as the multiplexing control device 9, the broadcast program management device 4, etc. When the transmission of schedule data from 12:10 is stopped, no program specification information PSI is broadcast.
[0032]
In this case, the IRD 18 receives the transport stream packet of the desired program on the basis of the program specification information PSI, so that the desired program is correctly transmitted even though other video data and the like are correctly broadcast. It becomes difficult to receive. Incidentally, in this case, even though other video data is being broadcast correctly, it seems to the user that the broadcast has stopped. In other words, in FIG. 9, for example, if the transmission of the schedule data is stopped during the transmission stop period, it becomes difficult to receive the original correct broadcast from 12:10. Similarly, when changing the broadcast content from 12:13, if the schedule data of 12:13 is not input, the broadcast cannot be viewed from the following 12:13.
[0033]
The present invention has been made in consideration of the above points. For example, a multiplexing apparatus capable of viewing various programs even when the transmission of a schedule is stopped by a host control apparatus that controls the operation of the multiplexing apparatus. A multiplex transmission system and a multiplex transmission method are proposed.
[0034]
[Means for Solving the Problems]
  To solve this problemClaim 1In the invention, in a multiplexing device for outputting multiplexed data,Inputting schedule data in which program specification information and a processing start time corresponding to the program specification information are paired, recording the schedule data or program specification information of the schedule data in a recording unit, and holding the recording unit; When the start time of one schedule data is reached based on the recording of the video, the video is based on the one schedule data until the start time of the schedule by other schedule data following the one schedule data. Data is time-division multiplexed to generate the multiplexed data, and program specification information based on the one schedule data is inserted into the multiplexed data.
[0035]
  AlsoThe invention of claim 3In a multiplex transmission system, at least schedule data in which control data for instructing the content of the encoding process and a start time for starting processing based on the control data are pairedThe schedule data or the control data of the schedule data is recorded and held in a recording unit, and when the start time of the one schedule data is reached based on the recording of the recording unit, the one schedule data The video data is encoded based on the control data based on the one schedule data until the start time of the schedule based on the other schedule data following.
[0036]
  AlsoThe invention of claim 4In multiplexed transmission systems,Inputting schedule data in which program specification information and a processing start time corresponding to the program specification information are paired, recording the schedule data or program specification information of the schedule data in a recording unit, and holding the recording unit; When the start time of one schedule data is reached based on the recording of the video, the video is based on the one schedule data until the start time of the schedule by other schedule data following the one schedule data. Data is time-division multiplexed to generate the multiplexed data, and program specification information based on the one schedule data is inserted into the multiplexed data.
[0037]
  furtherThe invention of claim 6In the multiplex transmission method, schedule data in which at least control data for instructing the content of encoding processing and a start time for starting processing based on the control data are pairedAnd recording the schedule data or the control data of the schedule data in the recording means, and based on the recording of the recording means, when the start time of the one schedule data is reached, A step of encoding the video data based on the control data based on the one schedule data until the start time of the schedule based on the other schedule data following the schedule data.
[0038]
  furtherThe invention of claim 7In the multiplexed transmission method,Inputting schedule data in which program specification information and processing start time corresponding to the program specification information are paired, recording and holding the schedule data or program specification information of the schedule data in a recording unit; and Based on the record of the recording means, when the start time of one schedule data is reached, until the start time of the schedule by other schedule data following the one schedule data, based on the one schedule data, The video data is time-division multiplexed to generate the multiplexed data, and the program specification information based on the one schedule data is inserted into the multiplexed data.
[0039]
  According to the configuration of claim 1, when the start time of one schedule data is reached based on the recording of the recording means, the time until the start time of the schedule by other schedule data following the one schedule data is reached. Based on one schedule data, the video data is time-division multiplexed to generate the multiplexed data, and program specification information based on the one schedule data is inserted into the multiplexed dataDue to a failure of the upper control device, etc.RisuWhen schedule data is not setButThe processing corresponding to the one schedule data is continued. As a result, various programs can be viewed even when the transmission of schedule data is stopped.
[0040]
  AlsoWith the configuration of claim 3,In multiplexed transmission systems,Based on the recording of the recording means, when the start time of one schedule data is reached, the video data is converted based on the control data by the one schedule data until the start time of the one schedule data is reached. Encoding processDue to a failure of the upper control device, etc.ContinuedEven if schedule data is not set, the processing corresponding to this one schedule data is continued, so that various programs can be viewed even when transmission of the schedule data is stopped.
[0041]
  AlsoAccording to the configuration of claim 4,In multiplexed transmission systems,Based on the record of the recording means, when the start time of one schedule data is reached, until the start time of the schedule by other schedule data following the one schedule data, based on the one schedule data, The video data is time-division multiplexed to generate the multiplexed data, and program specification information based on the one schedule data is inserted into the multiplexed data.However, similarly, even if a host control device fails, the processing corresponding to this one schedule data is continued, so that various programs can be viewed even if transmission of the schedule data is stopped. It becomes.
[0042]
  furtherWith the configuration of claim 6,In the multiplexed transmission method,Based on the recording of the recording means, when the start time of one schedule data is reached, the control data by the one schedule data until the start time of the schedule by another schedule data following the one schedule data is reached. The video data is encoded based onIf this is the case, the processing is continued even if a host control device fails or the like, and various programs can be viewed.
[0043]
  furtherWith the configuration of claim 7,In the multiplexed transmission method,Based on the record of the recording means, when the start time of one schedule data is reached, until the start time of the schedule by other schedule data following the one schedule data, based on the one schedule data, The video data is time-division multiplexed to generate the multiplexed data, and program specification information based on the one schedule data is inserted into the multiplexed data.If this is the case, the processing is continued even if a host control device fails or the like, and various programs can be viewed.
[0044]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
[0045]
(1) First embodiment
FIG. 2 is a block diagram showing the multiplexing apparatus according to the embodiment of the present invention together with the peripheral configuration. In the digital satellite broadcasting system according to this embodiment, a multiplexing control device 40 and a multiplexing device 41 are applied instead of the multiplexing control device 9 and the multiplexing device 10 described above with reference to FIG. In the configuration shown in FIG. 2, the same configurations as those of the digital satellite broadcasting system described above are denoted by the corresponding reference numerals, and redundant description is omitted.
[0046]
Here, the multiplexing control device 40 sends schedule data to the multiplexing device 41 according to the program information held by the broadcast program management device 4. At this time, the multiplexing control device 40 sends out schedule data in which “start time” and “contents of the program specification information PSI” are set in units of broadcast program change points. Here, the “contents of the program specification information PSI” is composed of various information necessary for creating the program specification information PSI. For example, information specifying video data and audio data corresponding to each service ID, information on the presence / absence of scramble processing Etc.
[0047]
Further, when the PMT, PAT, etc. are not sent out of the program specification information PSI, the multiplexing control device 40 does not set any “packet specification information PSI content” with respect to each packet for which transmission is stopped (multiplexing device). On the 41st side, this is regarded as an initial value), and “start time” and “contents of program specification information PSI” are notified.
[0048]
The central processing unit 42 registers the program specification information PSI in the schedule queue 43 according to the schedule data sent from the multiplexing control device 40 by executing a predetermined processing procedure. Here, the schedule queue 43 is a memory configured to be able to register, for example, 10 pieces of program specification information PSI. When the start time set in the schedule data is reached, the central processing unit 42 updates the contents of the PSI generator 12 with the corresponding program specification information PSI registered in the schedule queue 43, and sends the program specification information PSI. Further, the operation of the multiplexing unit 13 is controlled, and a plurality of systems of data D5A to D5N and D8A to D8N output from the encoders 5A to 5N and 8A to 8N corresponding to the schedule data are multiplexed and output. Further, the operation of the scramble circuit 44 is set as necessary, and a desired packet output from the multiplexing unit 13 is scrambled.
[0049]
Further, the central processing unit 42 is configured to be connected to a personal computer 45 via a predetermined interface, and receives a control command from the personal computer 45 independently of the control by the multiplexing control device 40, thereby causing a failure or the like. Thus, even when control by the multiplexing control device 40 becomes difficult, the operation of the multiplexing device 41 can be controlled by the personal computer 45.
[0050]
FIG. 3 is a flowchart showing the schedule data reception process of the central processing unit 42. The central processing unit 42 moves from step SP1 to step SP2, and receives schedule data from the multiplexing control device 40. Here, the central processing unit 42 stores data necessary for packet generation of PAT, PMT, CAT, NIT, and ECM (Entitlement Control Message) in a table format in accordance with “contents of program specification information PSI” of the received schedule data. Record in buffer. Further, the “start time” of the program specification information PSI is similarly recorded in the built-in buffer.
[0051]
Subsequently, the central processing unit 42 moves to step SP3 and confirms the contents of the created program specification information PSI. Here, for example, if an error is detected such that the “start time” is older than the current time, the central processing unit 42 moves to step SP4, notifies the multiplexing controller 40 of the error, and then moves to step SP5. The processing procedure ends.
[0052]
On the other hand, if no error is detected in the contents of the created program specification information PSI, the central processing unit 42 moves to step SP6 and sets the created program specification information PSI together with the corresponding start time in the schedule queue 43. sign up. Subsequently, the central processing unit 42 proceeds to step SP7, notifies the multiplexing control device 40 of the status indicating that the processing has been normally performed, and then proceeds to step SP5 to end the processing procedure. Thereby, the central processing unit 42 sequentially registers the program specification information PSI in the schedule queue 43 together with the corresponding start time.
[0053]
FIG. 1 is a flowchart showing a transmission processing procedure of the program specification information PSI registered in this way. When the operation is started, the central processing unit 42 executes this processing procedure at the transmission cycle of the program specification information PSI.
[0054]
That is, the central processing unit 42 proceeds from step SP10 to step SP11, initializes the contents of the schedule queue 43, and initializes the buffer of the PSI generating unit 12. Subsequently, the central processing unit 42 proceeds to step SP12, and sends the program specification information PSI to the multiplexing unit 13 for multiplexing according to the contents held in the buffer of the PSI generating unit 12. At this time, when the contents of the buffer of the PSI generation unit 12 are held in the initialized state, the central processing unit 42 controls the multiplexing unit 13 to stop multiplexing in the corresponding PMT, PAT, and the like. As a result, in this case, since the buffer of the PSI generator 12 is initialized, no program specification information PSI is transmitted from the multiplexer 41.
[0055]
Subsequently, the central processing unit 42 moves to step SP13, searches for the start time of the schedule data recorded in the schedule queue 43, and determines whether there is schedule data to be executed. If a negative result is obtained here, the central processing unit 42 returns to step SP12. On the other hand, if a positive result is obtained, the process proceeds to step SP14. Here, the central processing unit 42 loads the program specification information PSI that has reached the start time into the buffer of the PSI generating unit 12, and thereby starts sending out the program specification information PSI. Further, after starting the multiplexing process according to the program specification information PSI, the process proceeds to step SP12.
[0056]
As a result, the central processing unit 42 uses this schedule data from the start time of one schedule data recorded in the schedule queue 43 to the start time of the subsequent schedule data based only on the start time of the schedule data. The program specification information PSI is generated corresponding to the above and time division multiplexing processing is executed.
[0057]
In the above configuration, in the ground station 1 (FIG. 5), video data, audio data, etc. are read from the servers 2, 3 according to the program information managed by the broadcast program management device 4, and these video data, audio data, etc. Are encoded by the encoders 5A to 5N and 8A to 8N, and then multiplexed by the multiplexer 10. Further, the multiplexed data D10 (FIG. 2) generated by this multiplexing processing is modulated by the modulator 15, then frequency multiplexed, uplinked, and broadcast from the satellite E to the ground.
[0058]
On the other hand, on the receiving side (FIG. 8), after the frequency of the broadcast wave received via the antenna 17 is converted by the frequency converter 21, a desired modulation signal is obtained from the frequency-multiplexed broadcast wave at the front end unit 22. Select to demodulate the original multiplexed data. Further, in the transport unit 27, the video data and the audio data time-division multiplexed from the demodulated multiplexed data are converted into the original data sequence and processed in the subsequent decoder 30, and the video signal SV and the audio signal SA are converted. Demodulated.
[0059]
The video data and audio data transmitted in this way are multiplexed at a predetermined period as program specification information PSI indicating the correspondence between the packet ID assigned to each packet and the channel as data for program selection. Interpolated to generate multiplexed data D10.
[0060]
Correspondingly, on the receiving side, the frequency of the transponder to which the desired program is assigned is detected from the NIT of the program specification information PSI, and the packet ID of this program is detected from the PMT. From these detection results, The frequency of the modulation signal selected by the front end unit 22 is switched, and the packet separated by the transport unit 27 is switched. This makes it possible to easily select a desired program from a plurality of programs multiplexed and transmitted with the program selection reference data.
[0061]
Accordingly, when transmission of the program specification information PSI is stopped, it becomes difficult to view a desired program even if video data and audio data are correctly time-division multiplexed.
[0062]
In this embodiment, the multiplexing device 41 (FIG. 2), according to the schedule data in which the “start time” and the “contents of the program specification information PSI” sent from the multiplexing control device 40 are combined, is the central processing unit 42. The program specification information PSI is created and temporarily stored in the schedule queue 43. Only the “start time” is used as a reference, and the program specification information PSI temporarily stored in the schedule queue 43 is set in the PSI generation unit 42. Thus, the program specification information PSI is inserted into the multiplexed data at regular time intervals.
[0063]
At this time, the program specification information PSI is temporarily set in the schedule queue 43, and the program specification information PSI is set and transmitted to the PSI generation unit 42 based on only this “start time”. That is, from the start time of one schedule data to the start time of the subsequent schedule data, the program specification information PSI corresponding to this one schedule data is sent, and the corresponding multiplexing process is executed.
[0064]
As a result, in this embodiment, even when schedule data is not input due to a failure of the broadcast program management device 4 and the multiplexing control device 40, the program specification information PSI temporarily held in the schedule queue 43 is transmitted from the respective start times. In addition, the multiplexing processing corresponding to the program specification information PSI is continued to be executed independently from the control device 40, and even when the broadcast program management device 4 and the multiplexing control device 40 break down, the program can be correctly viewed. Is possible.
[0065]
Further, even when the program specification information PSI temporarily held in the schedule queue 43 is exhausted in this way, the schedule data corresponds to the schedule data from the start time of one schedule data to the start time of the subsequent schedule data. Since the program specification information PSI is transmitted, the program specification information PSI at the last start time is continuously output, and the corresponding multiplexing process is executed.
[0066]
That is, as shown in FIG. 4, the broadcast program is correctly changed from 12:13, and when the program specification information PSI is switched correspondingly, the schedule data starting at 12:13 is multiplexed. When not notified to the apparatus 41, the program specification information PSI based on the schedule data immediately before 12:10 is continuously output after 12:13, and the multiplexing processing corresponding to this program specification information PSI is executed. Is done.
[0067]
As a result, the broadcasting channel is different from that of the electronic program guide, and an abnormality such as that the program that is originally scrambled is not scrambled occurs, but at the receiving station side where it is determined that the broadcasting is completely stopped. The state where the broadcast cannot be viewed at all is effectively avoided, and various programs can be viewed.
[0068]
According to the above configuration, by switching the program specification information PSI based only on the start time of the schedule data, even if the transmission of the schedule data is stopped by the higher-level control device that controls the operation of the multiplexing device, it is continued. Thus, the program specification information PSI can be transmitted, and various programs can be viewed.
[0069]
(2) Other embodiments
In the above-described embodiment, when the program specification information PSI is not transmitted, the case where the content of the program specification information PSI is transmitted by the initial value in the multiplexing unit 13 has been described. However, the present invention is not limited to this. For example, the program specification information PSI may not be transmitted by notifying the schedule data without setting any data, or notifying the schedule data by setting specific data.
[0070]
In the above embodiment, the case where the program specification information PSI is created and stored in the schedule queue 43 has been described. However, the present invention is not limited to this, and the program specification information PSI is created at the start time. You may make it send out.
[0071]
In the above-described embodiment, the case where the switching process of the program specification information PSI is executed by the PSI generation unit 12 has been described. However, the present invention is not limited to this, and the PSI generation unit 12 is not limited to this by interrupt processing. An independent module may switch the program specification information PSI.
[0072]
Furthermore, in the above-described embodiment, the case where the program specification information PSI is generated and processed from the schedule data has been described. However, the present invention is not limited to this, and the direct start time and the program specification information PSI are assigned to the upper control device. You may notify more.
[0073]
In the above-described embodiment, the case where the present invention is applied to the multiplexing apparatus has been described. However, the present invention is not limited to this, and the encoding process is applied to the encoding apparatus based on only the start time. May be controlled. In this case, the higher-level control device notifies schedule data that is a set of control data that indicates the bit rate, etc., which is the content of the encoding process, and a start time for starting the encoding process based on this control data. . In the encoding apparatus, the video data encoding process is performed in accordance with the control data of the one schedule data from the start time of the one schedule data to the start time of the subsequent schedule data, based on only the start time. Will be executed.
[0074]
Further, in the above-described embodiment, the case where the present invention is applied to a digital satellite broadcasting system has been described. However, the present invention is not limited to this, and can be widely applied to various multiplexed transmission systems such as cable television. .
[0075]
【The invention's effect】
As described above, according to the present invention, by switching the operation based only on the start time of the schedule data, for example, even when the transmission of the schedule data is stopped by the host control device that controls the operation of the multiplexing device, Various programs can be viewed.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a processing procedure of a central processing unit according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a multiplexing device according to the first embodiment of the present invention.
FIG. 3 is a flowchart showing a processing procedure of schedule data in the central processing unit of FIG. 2;
4 is a time chart for explaining transmission of program specification information PSI according to the processing procedure of FIG. 1;
FIG. 5 is a block diagram showing a digital satellite broadcasting system.
FIG. 6 is a time chart for explaining time division multiplexing processing;
7 is a block diagram showing a multiplexing device in the digital satellite broadcasting system of FIG. 5. FIG.
8 is a block diagram showing IRD in the digital satellite broadcasting system of FIG.
9 is a time chart for explaining transmission of program specification information PSI in the digital satellite broadcasting system of FIG. 5;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Ground station, 4 ... Broadcast program management device, 5A-5N, 8A-8N ... Encoder, 9, 40 ... Multiplexing control device, 10, 41 ... Multiplexing device, 11, 42 ... Center Processing unit 12... PSI generator 13. Multiplexer 15. Modulator 43. Schedule queue

Claims (7)

In a multiplexing apparatus that outputs time-division multiplexed video data of at least a plurality of systems and outputs multiplexed data,
Input schedule data in which program specification information and a processing start time corresponding to the program specification information are paired, record the schedule data or program specification information of the schedule data in a recording means,
Based on the record of the recording means, when the start time of one schedule data is reached, based on the one schedule data until the start time of the schedule by other schedule data following the one schedule data. A multiplexing apparatus characterized in that the video data is time-division multiplexed to generate the multiplexed data, and program specification information based on the one schedule data is inserted into the multiplexed data . The multiplexing apparatus according to claim 1, wherein when the program specification information is a predetermined value, the insertion of the program specification information is stopped. In a multiplexed transmission system that performs time division multiplexing after encoding video data of at least a plurality of systems,
Input at least schedule data including a set of control data for instructing the content of the encoding process and a start time for starting the process based on the control data, and record the schedule data or the control data of the schedule data in a recording unit. Hold
Based on the recording of the recording means, when the start time of one schedule data is reached, the control by the one schedule data until the start time of the schedule by other schedule data following the one schedule data. A multiplexing transmission system , wherein the video data is encoded based on data . In a multiplexed transmission system that outputs multiplexed data by time-division multiplexing at least a plurality of systems of video data,
Input schedule data in which program specification information and a processing start time corresponding to the program specification information are paired, record the schedule data or program specification information of the schedule data in a recording means,
Based on the record of the recording means, when the start time of one schedule data is reached, based on the one schedule data until the start time of the schedule by other schedule data following the one schedule data. A multiplexed transmission system characterized in that the video data is time-division multiplexed to generate the multiplexed data, and program specification information based on the one schedule data is inserted into the multiplexed data . The multiplexed transmission system according to claim 4 , wherein when the program specification information is a predetermined value, the insertion of the program specification information is stopped. In a multiplex transmission method for encoding at least a plurality of systems of video data and then performing time division multiplexing and outputting,
Input at least schedule data including a set of control data for instructing the content of the encoding process and a start time for starting the process based on the control data, and record the schedule data or the control data of the schedule data in a recording unit. Holding and
Based on the recording of the recording means, when the start time of one schedule data is reached, the control by the one schedule data until the start time of the schedule by other schedule data following the one schedule data. based on the data, multiplex transmission method characterized by comprising the steps of: encoding processing the video data. In a multiplexing transmission method for outputting multiplexed data by time-division multiplexing at least a plurality of systems of video data,
Inputting schedule data in which program specification information and a processing start time corresponding to the program specification information are paired, and recording and holding the schedule data or program specification information of the schedule data in a recording unit;
Based on the record of the recording means, when the start time of one schedule data is reached, based on the one schedule data until the start time of the schedule by other schedule data following the one schedule data. And a method of generating the multiplexed data by time-division multiplexing the video data and interpolating program specification information based on the one schedule data into the multiplexed data. .

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