JP3469837B2 - Automatic gradation modulation sound switching device for digital broadcasting receiver - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hierarchical modulation voice automatic switching device for a digital broadcast receiving device, and more particularly to a C / N
The present invention relates to a technique useful when the (Carrier to Noise Ratio) deteriorates.

[0002]

2. Description of the Related Art Video signals are recorded using digital signal compression technology.
There is digital broadcasting in which an audio signal is compressed and a stream (transport stream) in which video / audio digital signals of a plurality of programs are time-division multiplexed is broadcast via a transponder (satellite repeater). Since there are a plurality of transponders and a plurality of channels are multiplexed in each transponder, the number of channels becomes a huge number of hundreds. A broadcast receiving apparatus for receiving such a digital multi-channel broadcast selects one of a plurality of transponders of a digital broadcast received through a dedicated antenna by a tuner, and selects one of a plurality of channels included in this one transponder. One is selected by demultiplexing processing, and the digital signal of the selected channel is decoded to output a video / audio signal.

[0003]

By the way, a digital BS (Broadcasting via Satellite) is used.
According to the operation standard for lite) broadcasting, transmission information is gradation-modulated and transmitted in order to prevent interruption of broadcasting due to C / N deterioration during rainfall from occurring earlier than in analog broadcasting. That is, the receiver side decodes a signal of high hierarchical modulation (TC8PSK) having high transmission efficiency when C / N is good, and has low transmission efficiency but C / N when C / N is deteriorated.
By decoding the low hierarchy modulation (QPSK) signal, which is relatively resistant to deterioration, it becomes possible to receive services as continuously as possible. In addition, PSI (Program Spec)
In the operation of if information), it is possible to duplicately refer to a plurality of higher layer voices to one lower layer voice, but this is not compulsory. Also,
When the operation that enables duplicate reference is used, P of low-level audio is used.
Since only one high layer can be referred to by the descriptor on SI, when returning to the higher layer, it is not guaranteed to return to the original high layer voice.

A conventional voice receiving process will be described with reference to FIG. First, the PID (Pack
et Identifier) is recognized (step S3
1) Obtain an elementary stream of higher layer audio that matches the PID (step S32). If, for example, the first voice (Japanese) and the second voice (English) are prepared as the higher layer voice, the elementary stream of the voice designated by the user's selection is acquired. The elementary stream of high-layer audio is decoded by the decoder and output as audio.
The receiver judges the quality of C / N (step S3).
3) If the C / N is good, the acquisition of the higher layer speech is continued. On the other hand, if the C / N is not good, it is determined whether or not low-layer audio is prepared (step S34).
This judgment is based on PMT (Program Map Tabl).
It can be determined by the descriptor indicating the elementary stream of low-layer audio in e). If low-layer audio is not prepared (when the broadcasting side is not in hierarchical operation), audio output is disabled (step S35), and if C / N is restored thereafter, acquisition of the original high-layer audio data Will be performed (steps S36 and S32).

As a method of preparing low-level audio on the broadcast station side, for example, there is a case where the low-level audio is prepared for Japanese and the low-level audio is not provided for English. In this case, when the viewer is listening to Japanese, C / N
At the time of deterioration, the Japanese low-level speech can be acquired by referring to the descriptor (step S37). Further, when the duplicate reference is enabled, even if the viewer listens to English, the Japanese low-level speech is acquired (step S37). The descriptor added to the lower hierarchy of Japanese indicates the higher hierarchy of Japanese as a return destination. Therefore, if the C / N is restored after that, Japanese high-level speech is acquired regardless of whether it is originally Japanese or English (steps S38, S39, S32).

The schematic diagram of FIG. 5 (a) shows a case where a low hierarchy exists for both the first voice and the second voice. In such a case, since there is a reference destination on both sides, there will be no problem in hierarchical migration.

The schematic diagram of FIG. 5 (b) shows a case in which a lower layer exists in the first voice, a lower layer does not exist in the second voice, and there is only one reference to the lower layer. That is, the case is shown where there is no lower hierarchy transition destination in the second voice. In such a case, since there is a reference destination for both the first voice, there is no problem in layer transition, but the second voice does not have a low hierarchy, so the voice disappears when C / N deteriorates.

The schematic diagram of FIG. 5 (c) shows a case where a low hierarchy exists in the first voice, a low hierarchy does not exist in the second voice, and duplicate reference is made to the low hierarchy. In this case,
Both voices shift to the lower hierarchy of the second voice when C / N deteriorates, but when listening to the second voice, it is not possible to return to the higher hierarchy of the second voice when returning to C / N. Therefore, the user has to select the voice again.

In view of the above circumstances, the present invention listens to the second voice when, for example, the first voice of the first voice and the second voice has a low hierarchy, but only one reference is made to the low hierarchy. Therefore, it is possible to avoid the problem that the voice disappears when the C / N deteriorates, and in this case, further, in this case, when the C / N is restored, it is possible to automatically return to the higher layer of the original second voice. An object of the present invention is to provide an automatic hierarchical modulation voice switching device.

[0010]

In order to solve the above-mentioned problems, a hierarchically modulated audio automatic switching apparatus for a digital broadcast receiving apparatus according to the present invention has at least a first audio and a second audio in a designated channel. With multiple voices,
Each of the plurality of voices has a high-layer voice having a high transmission efficiency, and one of the plurality of voices has a low-layer voice having a low transmission efficiency, and receives the plurality of voices. Receiving means, and a low-layer transition destination for acquiring and storing information necessary for transition of a voice having a low hierarchy among the first voice and the second voice received by the receiving means to the low hierarchy. Storage means and C / to judge pass / fail of C / N
N determination means and either the first voice or the second voice is selected, and when the C / N determination means determines that the C / N is deteriorated, the selected first voice or the second voice is selected. When there is no low-level voice in the first voice or the second voice, based on the transfer destination information stored in the storage means, the low-level voice existing from the first voice or the second voice And a low-layer migration control means for performing migration.

According to the above configuration, for example, when the first voice of the first voice and the second voice has a lower layer, but there is only one reference to the lower layer, that is, in the second voice, the lower layer transition destination is Even if there is no C / N while listening to the second voice
When the deterioration occurs, the transition to the lower layer of the first voice is compulsorily performed, so that it is possible to avoid the problem that the voice is lost.

[0012] When a transition to a low layer voice is made, a high layer return destination storage means for storing the voice type before the transition, and a high layer voice based on the voice type stored in the storage means at the time of C / N return. It is preferable to provide a higher hierarchy restoration control means for performing restoration of the above. According to this, when the C / N deterioration occurs while listening to the second voice and the C / N is forcibly changed to the lower hierarchy, the C / N is restored to the lower hierarchy of the first sound. It is possible to move to a higher hierarchy of the second voice regardless of the attached descriptor.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG.
It will be described with reference to FIG.

FIG. 1 shows a BS (Broadcasting).
(Via Satellite) FIG. 1 is a block diagram showing a digital broadcast receiving apparatus 30 of this embodiment for receiving digital broadcast.

The antenna 1 is arranged outdoors in a predetermined direction and receives a digital broadcast signal transmitted from a broadcasting satellite. This antenna 1 is equipped with a frequency converter, and a tuner 2 receives a signal received / frequency-converted.
Give to.

The tuner 2 extracts a signal of a specific frequency from the high frequency digital modulation signal containing video / audio data. That is, a process of selecting one from a plurality of transponders for digital broadcasting is performed. Further, the tuner 2 is equipped with an inverse interleave circuit, an error correction circuit, etc., so as to demodulate the selected digital modulation signal and output a transport stream. Further, the tuner 2 is configured to determine whether the C / N is good or bad at the selected specific frequency and supply the result of the C / N determination to the system controller 12. The quality of C / N is determined based on, for example, the error rate in the error correction circuit.

The demultiplexer (DEMUX) 3 converts the transport stream received from the tuner 2 into MPEG2 (Moving Picture Ex).
video transport packets, audio transport packets of P.
SI (Program Specific Info)
mate). The demultiplexer 3 supplies the video transport packet and the audio transport packet to the AV decoder 4, and supplies the service information and the like included in the PSI to the system controller 12. It should be noted that, as described above, a plurality of channels are multiplexed in the transport stream, and the processing for selecting an arbitrary channel from among these is the same as the above P.
This is possible by extracting data such as which packet ID is used to multiplex an arbitrary channel in the transport stream from the SI. Also, select the transport stream (select the transponder).
It can be performed based on SI information.

The AV decoder 4 comprises a video decoder for decoding video transport packets and an audio decoder for decoding audio transport packets. Video decoder
The input variable length code is decoded to obtain a quantized coefficient and a motion vector, and inverse DCT conversion and motion compensation control based on the motion vector are performed. The audio decoder decodes the input coded signal to generate audio data. The video data generated by decoding is output to the video processing circuit 5, and the audio data is output to the audio processing circuit 6. Here, for example, if there are Japanese and English as voices and the user selects English, this English elementary stream is separated by the demultiplexer 3, and English voice data is generated by the audio decoder. To be done. When the C / N is high, TC8PSK
Decoding processing corresponding to (higher layer audio) is performed and low C
When / N, a decoding process corresponding to QPSK (low hierarchical sound) is performed.

The video processing circuit 5 receives the video data from the AV decoder 4 and performs D / A conversion.
Convert to format composite signal. The audio signal processing circuit 6 receives the audio data output from the AV decoder 4 and performs D / A conversion to generate an analog audio signal. The video output circuit 7 and the audio output circuit 8 include output resistors and amplifiers.

The remote control transmitter 10 is a transmitter for sending a command to the broadcast receiving apparatus 30. When a key (not shown) provided on the remote control transmitter 10 is operated, a signal light (remote control signal) indicating a command corresponding to the key is sent from a light emitting unit (not shown). The remote control light receiver 11 receives the signal light, converts it into an electric signal, and gives it to the system controller 12.

The system controller 12 performs processing corresponding to various instructions from the user using the remote control transmitter 10 or the like. In addition, the system controller 12
A process of acquiring information necessary for transition of a voice having a lower layer among a plurality of voices in a channel designated by a user to the lower layer and storing the information in the memory 13, and C
/ N, when there is no low-level voice in the voice selected at the time of deterioration, control is performed to shift to the low-level voice based on the information stored in the memory 13. Further, the system controller 12 performs a process of storing the voice type before the transition in the memory 13 at the time of the transition to the low layer voice, and a higher layer based on the voice type stored in the memory 13 at the time of the C / N recovery. Control to return to voice. These controls do not require special hardware and can be handled by software.

The voice receiving process will be described with reference to FIG.
First, the elementary PID of the selected channel
Recognize (Packet Identifier) (step S11). At this time, if there is a low-level voice, the information necessary for the transition is acquired and stored (step S12). Next, an elementary stream of high-layer audio in the audio designated by the user is acquired (step S13). The receiver determines whether the C / N is good or bad (step S14), and if the C / N is good, the acquisition of the higher layer speech is continued. On the other hand, if the C / N is not good, information indicating the type of voice that is currently being listened to is stored (step S15), and then it is determined whether or not the lower layer voice of the voice that is currently being listened to is prepared (step S16). ). If the low-level voice of the voice currently listened to is prepared, this acquisition is continued until the C / N is restored (steps S22 and S23).

If the low-level audio of the audio currently being listened to is not prepared (when the broadcasting side is not performing hierarchical operation), it is determined whether or not the low-level audio of another audio is prepared (step S17). This judgment is made based on the information stored in the memory 13. If a lower layer voice of another voice is prepared, this acquisition is continued until the C / N is restored (steps S20 and S21). If no other low-level voice is prepared, the voice is kept silent until the C / N is restored (steps S18 and S19).

When the C / N is restored, the type of voice originally listened to is read from the memory 13 (step S2
4) Then, based on this information, an elementary stream of higher layer audio will be acquired (step S13).

FIG. 3 is a schematic diagram showing a mode of hierarchy transition based on the above-mentioned processing. In this figure, as multiple voices,
An example in which a first voice and a second voice exist is shown.

The schematic diagram of FIG. 3 (a) shows the case where a low hierarchy exists for both the first voice and the second voice. In such a case, since there is a reference destination on both sides, there will be no problem in hierarchical migration.

The schematic diagram of FIG. 3 (b) shows a case in which the lower layer exists in the first voice, the lower layer does not exist in the second voice, and there is only one reference to the lower layer. That is, the case is shown where there is no lower hierarchy transition destination in the second voice. The first voice can transit to a lower hierarchy of the first voice when the C / N is deteriorated, and can transit to a higher hierarchy of the first voice when the C / N is restored. As for the second voice, since there is no low-layer transition destination, the second voice is conventionally no voice, but in the present invention, when the C / N is deteriorated, the second voice is forcibly transitioned to the lower hierarchy. become. That is, if a low-layer audio is present in the selected broadcast, the low-level audio is always transmitted according to the information indicating the low-layer transition destination stored in the memory 13 regardless of the PSI information. Continue audio output. And
At the time of C / N restoration, the high hierarchy of the original second voice is changed according to the high hierarchy restoration destination stored in the memory 13.

Here, it is assumed that the user has selected a channel of a sports program, for example. Then, it is assumed that the broadcasting station does not have the descriptor for the transition to the lower hierarchy in the second audio. If C / N deterioration occurs while the user is listening to the second sound, the user will be forced to move to a lower hierarchy of the first sound, but in such a sports program, even if the sound is no sound, It is easier to get the atmosphere of watching sports by hearing the cheers of the audience and the voices of players. The program is not limited to sports programs, and there may be other programs in genres that can obtain such advantages.
For programs of a genre in which it is considered inconvenient to forcibly shift to a lower hierarchy, in view of the fact that genre information is obtained by PSI, execution / non-execution of the audio hierarchy transition according to the present invention is performed according to the genre. It may be controlled.

The schematic diagram of FIG. 3 (c) shows a case in which the low hierarchy exists in the first voice, the low hierarchy does not exist in the second voice, and duplicate reference is made to the low hierarchy. The first voice can transit to a lower hierarchy of the first voice when the C / N is deteriorated, and can transit to a higher hierarchy of the first voice when the C / N is restored. For the second voice, when the C / N deteriorates, it changes to the lower hierarchy of the first voice, and C / N
At the time of returning to N, it is possible to shift to the original higher layer of the second voice.

[0030]

As described above, the first embodiment of the first audio and the second audio has a low hierarchy although the hierarchical modulation audio automatic switching apparatus of the digital broadcast receiving apparatus of the present invention has a low hierarchy. Even when there is only one reference to the hierarchy, when C / N deterioration occurs while listening to the second sound,
Since it is possible to shift to a lower hierarchy of the first voice, it is possible to avoid the problem that the voice is lost. Then, when the C / N deterioration occurs while listening to the second sound and the C / N returns to the lower hierarchy, when the C / N returns, the descriptor attached to the lower hierarchy of the first sound. It is possible to make a transition to the original higher layer of the second voice regardless of the above.

[Brief description of drawings]

FIG. 1 is a hierarchical modulation voice automatic switching device of a digital broadcast receiving device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the contents of voice reception processing according to the embodiment of the present invention.

3 (a), (b) and (c) are schematic diagrams showing the modes of voice hierarchy transition according to the embodiment of the present invention.

FIG. 4 is a flowchart showing the contents of a conventional voice receiving process.

5 (a), (b), and (c) are schematic diagrams showing conventional speech hierarchy transitions.

[Explanation of symbols]

1 antenna 2 tuner 3 Demultiplexer (DEMUX) 4 AV decoder 12 System controller 13 memory

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Claims (2)

(57) [Claims] 1. A plurality of voices having at least a first voice and a second voice in a designated channel, wherein each of the plurality of voices has a high hierarchical voice with high transmission efficiency,
Further, one of the plurality of voices has a low hierarchical voice having low transmission efficiency, and a receiving unit that receives the plurality of voices, a first voice and a second voice that are received by the receiving unit. Low-layer transition destination storage means for acquiring and storing information necessary for transition of a voice in which a low hierarchy exists in the voice to the low hierarchy, and C / N determination means for determining whether the C / N is good or bad, When either the first voice or the second voice is selected and the C / N determination means determines that the C / N is deteriorated at the time of selection, the selected first voice or the second voice is selected. When there is no low-level voice in the second voice, the low-level voice that shifts to the existing low-level voice from the first voice or the second voice based on the transfer destination information stored in the storage means. And a transition control means. Hierarchical modulation Voice switching apparatus in a digital broadcasting receiver to. 2. The hierarchically modulated audio automatic switching apparatus for a digital broadcast receiving apparatus according to claim 1, wherein the first selected when the transition to the lower hierarchical speech is made before the transition.
High-level restoration destination storage means for storing the voice information of the voice or the second voice, and a high-level restoration for returning to the high-level voice based on the voice information stored in the storage means at the time of C / N restoration. A hierarchical modulation voice automatic switching device of a digital broadcast receiving device, characterized by comprising: a return control means.