JP3468411B2 - Digital broadcast receiver - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a digital broadcasting receiver for receiving digital broadcasting.

[0002]

2. Description of the Related Art Recently, digital broadcasting using a communication satellite (CS) has appeared, and with respect to broadcasting satellite (BS) and terrestrial broadcasting, a shift from analog broadcasting to digital broadcasting is under consideration. . In digital broadcasting, additional information can be transmitted together with program information such as a video signal and an audio signal, and thus has a feature that analog broadcasting such as an electronic program guide does not have.

By the way, according to the ARIB (Radio Industry Association) standard, in order to realize a channel selection operation of digital broadcasting,
A network information table (hereinafter referred to as NIT) is prepared as one of the additional information. NIT has
All transponder frequency array information currently used for broadcasting and channel array information for each transponder are described.

The digital broadcast receiver can perform the channel selection operation up to the selection of the transponder in the following sequence by acquiring the transponder frequency array information and the channel array information from the NIT and storing them. The viewer specifies an arbitrary channel number. Whether or not the designated channel number exists in the channel arrangement information acquired from NIT is referred to, and if it exists, the process proceeds to the next step. If it does not exist, the process ends. Refer to which transponder the channel corresponding to the specified channel number is included,
Select the transponder.

Subsequent channel selection processing is performed using an information table different from NIT. Since this is not directly related to the present invention, the description is omitted.

By the way, the information content of the NIT is not fixed, but the information content changes when the number of channels and transponders is increased or decreased due to the circumstances of the transmitting side. In order to notify the receiver side of this changed state, N
It is stipulated by the ARIB standard to attach a version number to IT. Generally, the version number is incremented by 1 each time the information content changes, but there are other cases.

When the version number changes, the receiver must judge that the information content of NIT has changed, and re-acquire the information content. The operation of this version number is entrusted to each broadcaster, which is the transmission side, and different operations are performed for each broadcaster. For example, in the broadcaster A, the version number is different although the information content of the NIT is exactly the same for each transponder. For B broadcasters, NIT of all transponders
Have the same version number. Also, regarding the timing of changing the information content of the NIT, the change is made once a day by the broadcaster A, but at the time it is changed by the broadcaster B.

When designing a receiver for the A broadcaster,
The version number is different for each transponder,
Since it is known that the contents of the NIT change at a certain time every day, it is possible to follow the change of the information contents by reacquiring the NIT according to the time.

When designing a receiver for a B broadcaster, the time at which the information content changes is indefinite, but the NIT version numbers of all transponders are the same, so
The NIT version number of the transponder selected first is stored, and the demultiplexer for separating the NIT is set to detect that the NIT having a version number different from that number is input. By doing so, if the version number of the NIT changes, the demultiplexer can automatically detect that the version number has been changed, and the changed information content can be taken into the CPU. This makes it possible to acquire new information content and follow changes in the information content.

[0010]

As described above, the NIT
Since the operation of the version number is different for each broadcaster, it is necessary to update the NIT corresponding to each broadcaster. Therefore, it hinders the generalization of the NIT update process, which leads to an increase in cost. Further, when designing a common receiver capable of receiving broadcasts from both the A broadcaster and the B broadcaster, the NIT update processing method must be changed for each broadcaster, There is a problem that the processing becomes complicated.

The present invention has been made in view of the above problems, and it is possible to deal with the change of the information content by the same process regardless of the operation method of the NIT version number. It is intended to provide a broadcast receiver.

[0012]

In order to solve the above-mentioned problems of the prior art, the present invention provides (a) digital broadcast reception for receiving a digital broadcast in which additional information is transmitted in addition to a video signal and an audio signal. Storage means (FIG. 1; 9) for storing transponder frequency array information and channel array information for each transponder included in the network information table in the additional information, and the version number of the network information table, Tuned to a transponder including the channel selected by the user and tuned to that channel, and then stored in the storage means and first acquisition means (FIG. 2; S8) for newly acquiring the version number of the network information table. Version number and the version number newly obtained by the first obtaining means Comparing means for comparing (Fig. 2; S9)
If the version number stored in the storage means and the version number newly acquired by the first acquisition means are different as a result of the comparison by the comparison means, the transponder frequency array information included in the network information table And second acquisition means (FIG. 2; S2) for reacquiring the channel arrangement information for each transponder, the version number newly acquired by the first acquisition means, and the second acquisition means for reacquisition. There is provided a digital broadcasting receiver characterized by comprising an updating means (FIG. 2; S2) for updating and storing transponder frequency array information and channel array information for each transponder in the storage means. ) Digital broadcasting reception for receiving digital broadcasting in which additional information is transmitted in addition to video and audio signals In FIG. 1, storage means (FIG. 1; 9) for storing transponder frequency arrangement information and channel arrangement information for each transponder included in the network information table in the additional information, and a predetermined number, A detecting means (FIG. 1; 7) for detecting that the program information has been changed while tuning to a transponder including the channel and selecting the channel, and the program information being changed by the detecting means. If it is detected, the first acquisition unit (FIG. 2; S8) for newly acquiring the version number of the network information table, and the version number stored in the storage unit and the first acquisition unit are newly added. The comparing means (FIG. 2; S9) for comparing the acquired version number with the comparing means. As a result of the comparison that,
If the version number stored in the storage means and the version number newly acquired by the first acquisition means are different, transponder frequency array information and channel array information for each transponder included in the network information table are acquired. A second acquisition means for fixing (FIG. 2;
S2), the version number newly acquired by the first acquisition unit, the transponder frequency array information and the channel array information for each transponder acquired again by the second acquisition unit are updated and stored in the storage unit. And a updating means (FIG. 2; S2) for controlling the digital broadcasting receiver.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A digital broadcast receiver of the present invention will be described below with reference to the accompanying drawings. 1 is a block diagram showing an embodiment of a digital broadcast receiver of the present invention,
FIG. 2 is a flow chart for explaining the operation of the digital broadcast receiver of the present invention.

First, the overall structure of the digital broadcast receiver of the present invention will be described. In FIG. 1, an intermediate frequency (RF) signal received by an antenna (not shown) is a network interface module (NIM).
Input to part 1. The NIM unit 1 tunes to a predetermined transponder frequency and demodulates it as a digital bit stream signal. The output of the NIM unit 1 is input to the descrambler unit 2, and if the bit stream signal is scrambled by pay broadcasting or the like, it is descrambled,
It is converted back to a regular bitstream signal. If the bit stream signal is not scrambled, it passes through the descrambler unit 2 as it is.

The output of the descrambler unit 2 is input to the demultiplexer unit 3 and separates the video signal (video data) or audio signal (audio data), which is program information, from the additional information (section data). This section data contains the network information table (NIT) described above.
Etc. are included.

The video data and audio data separated by the demultiplexing unit 3 are input to the MPEG decoding unit 4 and MPEG-decoded. As a result, the normal video signal and audio signal are restored. The section data separated by the demultiplexing unit 3 is RA
It is temporarily stored in M9 and analyzed by the CPU 7. The video data and audio data output from the MPEG decoding unit 4 are converted into analog signals by the DA converter unit 5 and output. The video data that is an analog signal is supplied to a display unit (not shown),
The audio data is supplied to a speaker (not shown).

Each part of these circuits is controlled by the CPU 7. A control program for operating the CPU 7 is stored in the ROM 8. The nonvolatile memory 6 is a so-called last memory, and stores various data in order to restore the state immediately before the power is turned off when the power of the receiver is turned on.

The operation of the digital broadcast receiver of the present invention thus constructed will be described in detail below. Figure 2
In step S0, when control of the receiver is started by turning on the power, etc., first, in step S1, first, C
The PU 7 controls the NIM unit 1 so as to tune to the initial transponder stored in the nonvolatile memory 6 in advance. The initial transponder is usually the transponder selected immediately before the power is turned off or the initial transponder manually set by the user, but the present invention is not limited to this.

In step S2, the NIT is extracted from the tuned data stream of the transponder, the transponder frequency array information and the channel array information for each transponder are obtained, and stored in the RAM 9. The receiver waits in this step S2 until the viewer inputs the channel number.

When an arbitrary channel number is input by the viewer in step S3, it is determined in step S4 whether the input channel number exists in the channel arrangement information stored in the RAM 9 in step S2 in advance. Reference all arrays. As a result, if the input channel number does not exist, the process returns to step S3 and waits until the next channel number is input.
If the input channel number exists, the process proceeds to step S5.

In step S5, it is determined in which transponder the channel corresponding to the input channel number is present by referring to the channel arrangement information stored in the RAM 9 and the transponder arrangement information. When the transponder is identified, the frequency information of the transponder is extracted and the NIM unit 1 is controlled to tune to the frequency.

In step S6, the following channel selection processing is performed. Specifically, the program association table (PAT), the program map table (PMT), and the like are acquired, analyzed, and finally the video stream and audio stream of the input channel are extracted and reproduced. The PAT and PMT are also separated by the demultiplexing unit 3 and analyzed by the CPU 7.

In step S7, when the state of the channel (program) is changed due to various factors while watching the same channel, step S for following the change.
Settings for performing interrupt processing when changing program information shown in 10 are performed. The various factors described above are, for example, when the viewing age restriction setting is changed, when the copy guard is changed from “absent” to “present”, and the like. In addition,
The change in the program information can be detected by the CPU 7 referring to the PAT or PMT. The CPU 7 also operates as a detection unit that detects a change in program information.

Then, in step S8, the version number of the NIT of the selected transponder is acquired. In step S9, the version number newly acquired this time is compared with the previous version number acquired and stored in the RAM 9 when the transponder was tuned last time. The RAM 9 has a storage area of version numbers corresponding to each transponder.
The comparison of version numbers in step S9 is performed for the same transponder.

If the version numbers are the same, it is determined that the information content of the NIT has not been changed, the process returns to step S3, and waits until the next channel number is input. If the version numbers are not the same, it is determined that the NIT information contents have been changed, and the process returns to step S2
The transponder frequency array information in the IT and the channel array information for each transponder are acquired again. Then, the process proceeds to step S3 and waits until the next channel number is input.

When a certain transponder is tuned for the first time and a predetermined channel therein is selected, the version number of the transponder is first obtained at that time in the process of step S8. Although the description is simplified in FIG. 2, in this case, the process is moved from step S9 to step S3.

After the above processing is completed, when the state of the selected channel changes while waiting in step S3, the interrupt processing for changing the program information set in step S7 becomes effective, and the processing from step S6 is newly added. Is done again. After changing the program information, the NIT version number comparison processing is performed in steps S8 and S9 just as in the normal channel selection. Normally, after changing the information content of NIT,
Since the contents of the program information are often changed, it is very effective to perform the NIT version number comparison process in the interrupt process in step S10.

As described above, the digital broadcast receiver of the present invention stands by in step S2 when the viewer does not input a new channel number. If the viewer inputs a new channel number, steps S3 to S
The processes up to 9 are performed. Further, even if the viewer does not input a new channel number, if the PAT or PMT changes and the program information is changed, the processing from step S6 to step S9 is performed.

As a result, the operation of the version number of the NIT is different for each broadcaster, and no matter what operation method the version number of the NIT is changed, the same processing can be used to change the information content. You can

[0030]

As described in detail above, the digital broadcast receiver of the present invention is provided with a network information table (NI).
T) the transponder frequency array information and the channel array information for each transponder, and the storage means for storing the version number of the NIT, and tuning to the transponder including the channel selected by the viewer to select that channel. After that, first acquisition means for newly acquiring the version number of NIT, and comparison means for comparing the version number stored in the storage means with the version number newly acquired by the first acquisition means,
As a result of the comparison by the comparison means, if the version number stored in the storage means and the version number newly acquired by the first acquisition means are different, the transponder frequency array information included in the NIT and the channel array for each transponder. Second acquisition means for reacquiring information,
An updating unit that updates and stores in the storage unit the version number newly acquired by the first acquiring unit, the transponder frequency array information and the channel array information for each transponder acquired again by the second acquiring unit, are provided. Since it is configured, even if the version number of the NIT is changed by any operation method, it is possible to deal with the change of the information content by the same processing. Further, a detecting means for detecting a change in the program information is provided while tuning to a transponder including a predetermined channel and selecting the channel, and the detecting means changes the program information. If is detected, the version number of the NIT is newly acquired, so that the version number can be updated more effectively.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flow chart for explaining the operation of the present invention.

[Explanation of symbols]

1 Network interface module 2 descrambler 3 Demultiplex part 4 MPEG decoding section 5 DA converter section 6 Non-volatile memory 7 CPU 8 ROM 9 RAM (storage means)

Claims (2)

(57) [Claims] 1. A digital broadcast receiver for receiving a digital broadcast in which additional information is transmitted in addition to a video signal and an audio signal, wherein transponder frequency array information and transponder-by-transponder included in a network information table in the additional information. After the channel arrangement information and the version number of the network information table are stored, the transponder including the channel selected by the viewer is tuned to the selected channel, and then the version number of the network information table is updated. First comparing means for comparing the version number stored in the storing means with a version number newly acquired by the first acquiring means, a comparison result by the comparing means, and Version number and previous stored in storage means If the version number newly obtained by the first obtaining means is different, the second obtaining means for re-obtaining the transponder frequency arrangement information and the channel arrangement information for each transponder included in the network information table; Update means for updating and storing in the storage means the version number newly acquired by the first acquisition means, the transponder frequency array information and the channel array information for each transponder acquired again by the second acquisition means. A digital broadcast receiver characterized by being configured as follows. 2. A digital broadcast receiver for receiving a digital broadcast in which additional information is transmitted in addition to a video signal and an audio signal, wherein the transponder frequency arrangement information and the transponder for each transponder included in the network information table in the additional information. The storage means for storing the channel arrangement information and the version number of the network information table, and the tuning of the transponder including the predetermined channel to select the channel, the program information is changed. Detecting means for detecting, first acquiring means for newly acquiring the version number of the network information table when the detecting means detects that the program information has been changed, and version number stored in the storing means And the bar newly acquired by the first acquisition means If the version number stored in the storage unit and the version number newly acquired by the first acquisition unit are different as a result of the comparison by the comparison unit, the network information Second acquisition means for reacquiring the transponder frequency array information and the channel array information for each transponder included in the table, the version number newly acquired by the first acquisition means, and the version number acquired by the second acquisition means. A digital broadcast receiver comprising an updating unit for updating and storing the corrected transponder frequency array information and the channel array information for each transponder in the storage unit.