# Patent

## Title
Audio processing apparatus

## Abstract

In an audio processing apparatus of the present invention, one or two audio signals selected from a surround rear left audio signal, a left outer audio signal and a left upper audio signal is (are) amplified to be outputted from a speaker terminal(s) corresponding to this (these) channel(s) without necessity to provide amplifiers of all channels. When the surround rear left audio signal is included, a switch S13a is turned ON to supply the surround rear left audio signal amplified by an amplifier 12a to a SP terminal 14a. When the left outer audio signal is included, a switch 13b is turned ON to supply the left outer audio signal amplified by the amplifier 12a to a SP terminal 14b, or a switch 13c is turned ON to supply the left outer audio signal amplified by an amplifier 12b to the SP terminal 14b. When the left upper audio signal is included, a switch 13d is turned ON to supply the left upper audio signal amplified by the amplifier 12b to a SP terminal 14c.

## Background
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an audio processing apparatus that reproduces multichannel audio data.
2. Description of the Related Art
An audio reproducing system including a BD (Blu-ray Disc) player, an AV amplifier and a display apparatus has been utilized. The audio data transmitted from the BD player to the AV amplifier is obtained by encoding multichannel audio data. For example, the multichannel audio data includes a left audio signal L, a right audio signal R, a central audio signal C, a low-frequency audio signal SW, a surround left audio signal SL, and a surround right audio signal SR, as shown in FIG. 3. Recently, audio formats relating to HD (High Definition) such as Dolby True HD, Dolby Digital Plus, DTS-HD and the like, which are used in the BD player, have emerged, and in these formats, a surround rear left audio signal SBL, a surround rear right audio signal SBR, a left outer audio signal LW, a right outer audio signal RW, a left upper audio signal LH, and a right upper audio signal RH are further added.
However, if amplifiers corresponding to the audio signals of all these channels are provided in the AV amplifier, the amplifiers of a total of 11.1 channels will be provided, thus largely increasing a cost. This is true in the case where in place of any one of the above-described extended channels (or in addition to the above-described extended channels), a left central audio signal LC, and a right central audio signal RC are added, as shown in FIG. 8. Furthermore, this is also true in the case where the AV amplifier generates the above-described extended channels in a DSP in accordance with a listening mode.
SUMMARY OF THE INVENTION
The present invention is achieved in order to solve the above-described conventional problem, and an object thereof is to provide an audio processing apparatus capable of amplifying one or two audio signals selected from a first extended left audio signal, a second extended left audio signal, and a third extended left audio signal to be outputted from a speaker terminal(s) corresponding this (these) channels without necessity to provide amplifiers of all channels.
According to a preferred embodiment of the present invention, an audio processing apparatus comprises: a first amplifying unit that amplifies a first extended audio signal or a second extended audio signal, the first extended audio signal being a first extended left audio signal or a first extended right audio signal, and the second extended audio signal being a second extended left audio signal or a second extended right audio signal; a second amplifying unit that amplifies a second extended audio signal or a third extended audio signal, the third extended audio signal being a third extended left audio signal or a third extended right audio signal; a first speaker terminal that outputs the first extended audio signal; a second speaker terminal that outputs the second extended audio signal; a third speaker terminal that outputs the third extended audio signal; a first switch that performs switching as to whether or not the first extended audio signal from the first amplifying unit is to be supplied to the first speaker terminal; a second switch that performs switching as to whether or not the second extended audio signal from the first amplifying unit is to be supplied to the second speaker terminal; a third switch that performs switching as to whether or not the second extended audio signal from the second amplifying unit is to be supplied to the second speaker terminal; a fourth switch that performs switching as to whether or not the third extended audio signal from the second amplifying unit is to be supplied to the third speaker terminal; a channel determining unit that determines which of the first extended audio signal, the second extended audio signal, and the third extended audio signal is included in multichannel audio data; and a switching control unit that if it is determined that the first extended audio signal is included, causes the first switch to supply the first extended audio signal amplified by the first amplifying unit to the first speaker terminal, if it is determined that the second extended audio signal is included, causes the second switch to supply the second extended audio signal amplified by the first amplifying unit to the second speaker terminal, or causes the third switch to supply the second extended audio signal amplified by the second amplifying unit to the second speaker terminal, and if it is determined that the third extended audio signal is included, causes the fourth switch to supply the third extended audio signal amplified by the second amplifying unit to the third speaker terminal.
Which channel is included in the multichannel audio data is determined, and the included channel is amplified by the first amplifying unit or by the second amplifying unit, so that by providing only the two amplifying units, one or two audio signals selected from the first extended left audio signal, the second extended left audio signal, and the third extended left audio signal can be amplified to be outputted to the speaker terminal(s) corresponding to this (these) channel(s). Similarly, by providing only the two amplifying units, one or two audio signals selected from the first extended right audio signal, the second extended right audio signal, and the third extended right audio signal can be amplified to be outputted to the speaker terminal(s) corresponding to this (these) channel(s).
Preferably, the first extended left audio signal is any of a surround rear left audio signal, a left outer audio signal, a left upper audio signal and a left central audio signal, and the first extended right audio signal is any of a surround rear right audio signal, a right outer audio signal, a right upper audio signal and a right central audio signal, the second extended left audio signal is any of the surround rear left audio signal, the left outer audio signal, the left upper audio signal and the left central audio signal, and is different from the first extended left audio signal, and the second extended right audio signal is any of the surround rear right audio signal, the right outer audio signal, the right upper audio signal and the right central audio signal, and is different from the first extended right audio signal, and the third extended left audio signal is any of the surround rear left audio signal, the left outer audio signal, the left upper audio signal and the left central audio signal, and is different from the first extended left audio signal and the second extended left audio signal, and the third extended right audio signal is any of the surround rear right audio signal, the right outer audio signal, the right upper audio signal and the right central audio signal, and is different from the first extended right audio signal and the second extended right audio signal.
Preferably, if it is determined that the first extended audio signal is not included and that the second extended audio signal is included, the switching control unit causes the second switch to supply the second extended audio signal amplified by the first amplifying unit to the second speaker terminal, and if it is determined that the first extended audio signal is included and that the second extended audio signal is included, the switching control unit causes the third switch to supply the second extended audio signal amplified by the second amplifying unit to the second speaker terminal.
Preferably, if it is determined that the first extended audio signal and the second extended audio signal are included, the switching control unit causes the first switch to supply the first extended audio signal amplified by the first amplifying unit to the first speaker terminal, and causes the third switch to supply the second extended audio signal amplified by the second amplifying unit to the second speaker terminal, if it is determined that the first extended audio signal and the third extended audio signal are included, the switching control unit causes the first switch to supply the first extended audio signal amplified by the first amplifying unit to the first speaker terminal, and causes the fourth switch to supply the third extended audio signal amplified by the second amplifying unit to the third speaker terminal, and if it is determined that the second extended audio signal and the third extended audio signal are included, the switching control unit causes the second switch to supply the second extended audio signal amplified by the first amplifying unit to the second speaker terminal, and causes the fourth switch to supply the third extended audio signal amplified by the second amplifying unit to the third speaker terminal.
Preferably, if it is determined that the first extended audio signal, the second extended audio signal, and the third extended audio signal are included, the switching control unit operates so that the two audio signals set by user operation in advance are supplied to the respective corresponding speaker terminals.
Preferably, the first amplifying unit amplifies the first extended audio signal, the second extended audio signal, or a fourth extended audio signal, the fourth extended audio signal being a fourth extended left audio signal or a fourth extended right audio signal, the second amplifying unit amplifies the second extended audio signal, the third extended audio signal or the fourth extended audio signal, the audio processing apparatus further comprises: a fourth speaker terminal that outputs the fourth extended audio signal; a fifth switch that performs switching as to whether or not the fourth extended audio signal from the first amplifying unit is to be supplied to the fourth speaker terminal; and a sixth switch that performs switching as to whether or not the fourth extended audio signal from the second amplifying unit is to be supplied to the fourth speaker terminal, the channel determining unit further determines whether or not the fourth extended audio signal is included in the multichannel audio data, and if it is determined that the fourth extended audio signal is included, the switching control unit causes the fifth switch to supply the fourth extended audio signal amplified by the first amplifying unit to the fourth speaker terminal, or causes the sixth switch to supply the fourth extended audio signal amplified by the second amplifying unit to the fourth speaker terminal.
Preferably, the audio processing apparatus further comprises a pre-out terminal that outputs the second extended audio signal at a stage before supplying the same to the first amplifying unit or the second amplifying unit, and if it is determined that the first extended audio signal, the second extended audio signal, and the third extended audio signal are included, the switching control unit causes the first switch to supply the first extended audio signal amplified by the first amplifying unit to the first speaker terminal, causes the fourth switch to supply the third extended audio signal amplified by the second amplifying unit to the third speaker terminal, and causes the second extended audio signal to be outputted from the pre-out terminal.
Preferably, the audio processing apparatus further comprises: a first pre-out terminal that outputs the second extended audio signal at a stage before supplying the same to the first amplifying unit or the second amplifying unit; and a second pre-out terminal that outputs the fourth extended audio signal at the stage before supplying the same to the first amplifying unit or the second amplifying unit, wherein if it is determined that the first extended audio signal, the second extended audio signal, the third extended audio signal, and the fourth extended audio signal are included, the switching control unit causes the first switch to supply the first extended audio signal amplified by the first amplifying unit to the first speaker terminal, causes the fourth switch to supply the third extended audio signal amplified by the second amplifying unit to the third speaker terminal, causes the second extended audio signal to be outputted from the first pre-out terminal, and causes the fourth extended audio signal to be outputted from the second pre-out terminal.
Preferably, the audio processing apparatus further comprises: a third amplifying unit that amplifies the second extended audio signal or a fourth extended audio signal, the fourth extended audio signal being a fourth extended left audio signal or a fourth extended right audio signal; a fourth speaker terminal that outputs the fourth extended audio signal; a fifth switch that performs switching as to whether or not the second extended audio signal from the third amplifying unit is to be supplied to the second speaker terminal; and a sixth switch that performs switching as to whether or not the fourth extended audio signal from the third amplifying unit is to be supplied to the fourth speaker terminal, wherein the channel determining unit further determines whether or not the fourth extended audio signal is included in the multichannel audio data, and if it is determined that the second extended audio signal is included, the switching control unit causes the second switch to supply the second extended audio signal amplified by the first amplifying unit to the second speaker terminal, causes the third switch to supply the second extended audio signal amplified by the second amplifying unit to the second speaker terminal, or causes the fifth switch to supply the second extended audio signal amplified by the third amplifying unit to the second speaker terminal, and if it is determined that the fourth extended audio signal is included, the switching control unit causes the sixth switch to supply the fourth extended audio signal amplified by the third amplifying unit to the fourth speaker terminal.
Preferably, the audio processing apparatus further comprises a pre-out terminal that outputs the second extended audio signal at a stage before supplying the same to the first amplifying unit, the second amplifying unit, or the third amplifying unit, and if it is determined that the first extended audio signal, the second extended audio signal, the third extended audio signal, and the fourth extended audio signal are included, the switching control unit causes the first switch to supply the first extended audio signal amplified by the first amplifying unit to the first speaker terminal, causes the fourth switch to supply the third extended audio signal amplified by the second amplifying unit to the third speaker terminal, causes the sixth switch to supply the fourth extended audio signal amplified by the third amplifying unit to the fourth speaker terminal, and causes the second extended audio signal to be outputted from the pre-out terminal.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing arrangement of an AV amplifier 1 and speakers.
FIG. 2 is a diagram showing an audio reproducing system.
FIG. 3 is a diagram showing channels of audio signals.
FIG. 4 is a diagram showing an audio processing unit 5.
FIG. 5 is a flowchart showing processing of a control unit 2.
FIG. 6 is a flowchart showing the processing of the control unit 2.
FIG. 7 is a diagram showing an audio processing unit 5A.
FIG. 8 is a diagram showing channels of audio signals.
FIG. 9 is a diagram showing an audio processing unit 5B.
FIG. 10 is a diagram showing an audio processing unit 5C.
FIG. 11 is a flowchart showing processing of the control unit 2.
FIG. 12 is a flowchart showing the processing of the control unit 2.
FIG. 13 is a flowchart showing the processing of the control unit 2.
FIG. 14 is a diagram showing an audio processing unit 5D.
FIG. 15 is a flowchart showing processing of the control unit 2.
FIG. 16 is a flowchart showing the processing of the control unit 2.
FIG. 17 is a flowchart showing the processing of the control unit 2.
FIG. 18 is a diagram showing an audio processing unit 5E.
FIG. 19 is a diagram showing an audio processing unit 5F.
FIG. 20 is a diagram showing an audio processing unit 5G.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, an audio reproducing system according to preferred embodiments of the present invention, including a disk reproducing apparatus (hereinafter, referred to as a BD player), an audio processing apparatus (hereinafter, referred to as an AV amplifier), and a display apparatus is specifically described with reference to the drawings. However, the present invention is not limited to these embodiments. FIG. 1 is a diagram for explaining one example of arrangement of an AV amplifier 1, and respective speakers. To the AV amplifier 1 are connected a left speaker SL, a right speaker SR, a central speaker SC, a low-frequency speaker SSW, a surround left speaker SSL, a surround right speaker SSR, a surround rear left speaker SSBL, a surround rear right speaker SSBR, a left upper speaker SLH, a right upper speaker SRH, a left outer speaker SLW, and a right outer speaker SRW.
FIG. 2 is a block diagram showing a configuration of the audio reproducing system. A BD player 100, the AV amplifier 1 and a display apparatus 200 conform to, for example, an HDMI standard, and are connected to one another through an HDMI cable. The BD player 100 transmits HDMI data including multichannel audio data and video data to the AV amplifier 1. The AV amplifier 1 amplifies the multichannel audio data included in the HDMI data received from the BD player 100 to output to the speakers. Moreover, the AV amplifier 1 transmits the HDMI data including the video data to the display apparatus 200. The display apparatus 200 displays the video data included in the HDMI data received from the AV amplifier 1.
The AV amplifier 1 has a control unit 2, an HDMI receiving unit 3, an HDMI transmitting unit 4, an audio processing unit 5, an operation unit 6, a display unit 7, and HDMI terminals 8, 9. To the AV amplifier 1 is connected a speaker 300 (corresponding to each of the speakers in FIG. 1).
The control unit 2 includes a channel determining unit 400 that determines which audio signals are included in the multichannel audio data. Control unit 2 further includes a switching control unit 500 that controls whether each switch supplies a respective audio signal to a speaker terminal. Hereinafter, the control unit 2 may be referred to generally as controlling the processes controlled by the channel determining unit 400 and switching control unit 500.
The HDMI receiving unit 3 receives the HDMI data transmitted from the BD player 100, generates the original video data from the received HDMI data to supply to the HDMI transmitting unit 4. Moreover, the HDMI receiving unit 3 generates the original multichannel audio data from the received HDMI data to supply to the audio processing unit 5.
The audio processing unit 5 decodes the multichannel audio data supplied from the HDMI receiving unit 3, executes various types of processing such as sound processing, D/A conversion processing, volume adjustment processing, amplification processing and the like to supply the audio signal of each of the channels to the speaker 300. The multichannel audio data supplied to the audio processing unit 5 is described. In audio formats relating to HD (High Definition) such as Dolby True HD, Dolby Digital Plus, DTS-HD and the like, as shown in FIG. 3, for example, a left audio signal L (front left audio signal), a right audio signal R (front right audio signal), a central audio signal C, a low-frequency audio signal SW, a surround left audio signal SL, a surround right audio signal SR, a surround rear left audio signal SBL, a surround rear right audio signal SBR, a left outer audio signal LW, a right outer audio signal RW, a left upper audio signal LH, a right upper audio signal RH and the like are included.
The surround rear left audio signal SBL is an audio signal reproduced at a position on the rear left side of a user. The surround rear right audio signal SBR is an audio signal reproduced at a position on the rear right side of the user. The left outer audio signal LW is an audio signal reproduced at a position outside (on the left side of) the left audio signal L (i.e., on the front left outer side of a user). The right outer audio signal RW is an audio signal reproduced at a position outside (on the right side of) the right audio signal R (i.e., on the front right outer side of the user). The left upper audio signal LH is an audio signal reproduced at a position above the left audio signal L (i.e., on the front left upper side of the user). The right upper audio signal RH is an audio signal reproduced at a position above the right audio signal R (i.e., on the front right upper side of the user).
FIG. 4 is a block diagram showing a substantial part of the audio processing unit 5. The audio processing unit 5 has a pre-out unit 11, a power amplifier 12, a SP (speaker) relay 13, and a SP (speaker) terminal 14. In FIG. 4, since respective circuits relating to the basic 5.1 channels (the left audio signal L, the right audio signal R, the central audio signal C, the low-frequency audio signal SW, the surround left audio signal SL, and the surround right audio signal SR) are the same as those in conventional art, they are omitted. Moreover, a DSP and the like provided at a previous stage of the pre-out unit 11 are also omitted.
The DSP decodes and D/A converts the multichannel audio data supplied from the HDMI receiving unit 3 to generate the audio signals of the respective channels. The generated audio signals are supplied to the pre-out unit 11.
The pre-out unit 11 has switches S11a to S11h. The switch S11a performs switching as to whether or not the surround rear left audio signal SBL is to be outputted to an amplifier 12a. The switch S11b performs switching as to whether or not the left outer audio signal LW is to be outputted to the amplifier 12a. The switch S11c performs switching as to whether or not the left upper audio signal LH is to be outputted to an amplifier 12b. The switch S11d performs switching as to whether or not the left outer audio signal LW is to be outputted to the amplifier 12b. Any one of the switches S11a, S11b is turned ON in accordance with the channel included in the multichannel audio data. Any one of the switches S11c, S11d is turned ON in accordance with the channel included in the multichannel audio data.
The switch S11e performs switching as to whether or not the surround rear right audio signal SBR is to be outputted to an amplifier 12c. The switch S11f performs switching as to whether or not the right outer audio signal RW is to be outputted to the amplifier 12c. The switch S11g performs switching as to whether or not the right upper audio signal RH is to be outputted to an amplifier 12d. The switch S11h performs switching as to whether or not the right outer audio signal RW is to be outputted to the amplifier 12d. Any one of the switches S11e, S11f is turned ON in accordance with the channel included in the multichannel audio data. Any one of the switches S11g, S11h is turned ON in accordance with the channel included in the multichannel audio data.
The pre-out unit 11 may not include the switches S11a to S11h, but the DSP may change the channels of the audio signals to be supplied to the amplifiers 12a to 12d in accordance with the channels included in the multichannel audio data.
The power amplifier 12 has the amplifiers 12a to 12d. The amplifier 12a amplifies the surround rear left audio signal SBL or the left outer audio signal LW supplied from the pre-out unit 11 to supply to the SP relay 13 (switches S13a, S13b). The amplifier 12b amplifies the left upper audio signal LH or the left outer audio signal LW supplied from the pre-out unit 11 to supply to the SP relay 13 (switches S13c, S13d). The amplifier 12c amplifies the surround rear right audio signal SBR or the right outer audio signal RW supplied from the pre-out unit 11 to supply to the SP relay 13 (switches S13e, S13f). The amplifier 12d amplifies the right upper audio signal RH or the right outer audio signal RW supplied from the pre-out unit 11 to supply to the SP relay 13 (switches S13g, S13h).
The SP relay 13 has the relay switches (hereinafter, referred to as switches) S13a to S13h. The switch S13a performs switching as to whether or not the surround rear left audio signal SBL supplied from the amplifier 12a is to be supplied to a surround rear left SP terminal 14a. The switch S13b performs switching as to whether or not the left outer audio signal LW supplied from the amplifier 12a is to be supplied to a left outer SP terminal 14b. The switch S13c performs switching as to whether or not the left outer audio signal LW supplied from the amplifier 12b is to be supplied to the left outer SP terminal 14b. The switch S13d performs switching as to whether or not the left upper audio signal LH supplied from the amplifier 12b is to be supplied to a left upper SP terminal 14c. The switches S13a to S13d are switched in accordance with the channels included in the multichannel audio data.
The switch S13e performs switching as to whether or not the surround rear right audio signal SBR supplied from the amplifier 12c is to be supplied to a surround rear right SP terminal 14d. The switch S13f performs switching as to whether or not the right outer audio signal RW supplied from the amplifier 12c is to be supplied to a right outer SP terminal 14e. The switch S13g performs switching as to whether or not the right outer audio signal RW supplied from the amplifier 12d is to be supplied to the right outer SP terminal 14e. The switch S13h performs switching as to whether or not the right upper audio signal RH supplied from the amplifier 12d is to be supplied to a right upper SP terminal 14f. The switches S13e to S13h are switched in accordance with the channels included in the multichannel audio data.
The SP terminal 14 has the SP terminals 14a to 14f. The surround rear left speaker SSBL is connected to the surround rear left SP terminal 14a. The left outer speaker SLW is connected to the left outer SP terminal 14b. The left upper speaker SLH is connected to the left upper SP terminal 14c. The surround rear right speaker SSBR is connected to the surround rear right SP terminal 14d. The right outer speaker SRW is connected to the right outer SP terminal 14e. The right upper speaker SRH is connected to the right upper SP terminal 14f. 
Referring back to FIG. 2, the HDMI transmitting unit 4 converts the video data supplied from the HDMI receiving unit 3 to the HDMI data to transmit to the display apparatus 200.
The control unit 2 controls the respective units, based on an operation program of the AV amplifier stored in a memory not shown, which is built in or connected, and is, for example, a microcomputer, a CPU or the like. The control unit 2 determines the channels included in the multichannel audio data to control the switching of the switches S11a to S11h, S13a to S13h (the multichannel audio data is not limited to the audio data received from the BD player 100, but may be audio data outputted from the DSP). That is, if it is determined that the surround rear left audio signal SBL is included, the control unit 2 causes the switch S13a to supply the surround rear left audio signal SBL amplified by the amplifier 12a to the SP terminal 14a. If it is determined that the left outer audio signal LW is included, the control unit 2 causes the switch S13b to supply the left outer audio signal LW amplified by the amplifier 12a to the SP terminal 14b, or causes the switch S13c to supply the left outer audio signal LW amplified by the amplifier 12b to the SP terminal 14b. If it is determined that the left upper audio signal LH is included, the control unit 2 causes the switch S13d to supply the left upper audio signal LH amplified by the amplifier 12b to the SP terminal 14c. The foregoing is applied to the respective right signals.
The HDMI receiving unit 3 generates the original multichannel audio data from the HDMI data to supply to the audio processing unit 5. The audio processing unit 5 decodes the multichannel audio data to read channel information included in an information area thereof and supply the same to the control unit 2.
Hereinafter, operation of the present invention is described. FIG. 5 is a flowchart showing switching processing of the pre-out unit 11 by the control unit 2. The control unit 2 determines which (one or two) of combination of the surround rear left audio signal SBL and the surround rear right audio signal SBR, combination of the left upper audio signal LH and the right upper audio signal RH and combination of the left outer audio signal LW and the right outer audio signal RW is (are) included, based on the channel information of the input signals included in the multichannel audio data supplied from the audio processing unit 5.
First, the control unit 2 determines whether or not the combination of the surround rear left audio signal SBL and the surround rear right audio signal SBR is included (S1). If it is included (YES in S1), the control unit 2 controls the switches so as to supply the surround rear left audio signal SBL to the surround rear left SP terminal 14a, and to supply the surround rear right audio signal SBR to the surround rear right SP terminal 14d. That is, the control unit 2 controls the switches S11a, S11e to be in an ON state, and the switches S11b, S11f to be in an OFF state (S2).
Next, the control unit 2 further determines whether or not the combination of the left upper audio signal LH and the right upper audio signal RH is included in the multichannel audio data (S3). If it is included (YES in S3), the control unit 2 controls the switches so as to supply the left upper audio signal LH to the left upper SP terminal 14c, and to supply the right upper audio signal RH to the right upper SP terminal 14f. That is, the control unit 2 controls the switches S11c, S11g to be in an ON state, and the switches S11d, S11h to be in an OFF state (S4).
On the other hand, if the combination of the left upper audio signal LH and the right upper audio signal RH is not included in the multichannel audio data in S3, the control unit 2 controls the switches so as to supply the left outer audio signal LW to the left outer SP terminal 14b, and to supply the right outer audio signal RW to the right outer SP terminal 14e. That is, the control unit 2 controls the switches S11d, S11h to be in an ON state, and the switches S11c, S11g to be in an OFF state (S5).
If the combination of the surround rear left audio signal SBL and the surround rear right audio signal SBR is not included in the multichannel audio data in S1, the control unit 2 controls the switches so as to supply the left outer audio signal LW to the left outer SP terminal 14b, to supply the right outer audio signal RW to the right outer SP terminal 14e, to supply the left upper audio signal LH to the left upper SP terminal 14c, and to supply the right upper audio signal RH to the right upper SP terminal 14f. That is, the control unit 2 controls the switches S11b, S11c, S11f, S11g to be in an ON state, and the switches S11a, S11d, S11e, S11h to be in an OFF state (S6).
FIG. 6 is a flowchart showing SP relay switching processing by the control unit 2. The control unit 2 determines whether or not the combination of the surround rear left audio signal SBL and the surround rear right audio signal SBR is included (S11). If it is included (YES in S11), the control unit 2 controls the switches so as to supply the surround rear left audio signal SBL to the surround rear left SP terminal 14a, and to supply the surround rear right audio signal SBR to the surround rear right SP terminal 14d. That is, the control unit 2 controls the switches S13a, S13e to be in an ON state, and the switches S13b, S13f to be in an OFF state (S12).
Next, the control unit 2 further determines whether or not the combination of the left upper audio signal LH and the right upper audio signal RH is included in the multichannel audio data (S13). If it is included (YES in S13), the control unit 2 controls the switches so as to supply the left upper audio signal LH to the left upper SP terminal 14c, and to supply the right upper audio signal RH to the right upper SP terminal 14f. That is, the control unit 2 controls the switches S13d, S13h to be in an ON state, and the switches S13c, S13g to be in an OFF state (S14).
On the other hand, if the combination of the left upper audio signal LH and the right upper audio signal RH is not included in S13, the control unit 2 controls the switches S13d, S13h to be in an OFF state so as not to supply the left upper audio signal LH to the left upper SP terminal 14c, and not to supply the right upper audio signal RH to the right upper SP terminal 14f (S15). The control unit 2 further determines whether or not the combination of the left outer audio signal LW and the right outer audio signal RW is included in the multichannel audio data (S16). If it is included (YES in S16), the control unit 2 controls the switches so as to supply the left outer audio signal LW to the left outer SP terminal 14b, and to supply the right outer audio signal RW to the right outer SP terminal 14e. That is, the control unit 2 controls the switches S13c, S13g to be in an ON state (S17).
If the combination of the left outer audio signal LW and the right outer audio signal RW is not included in S16, the control unit 2 controls the switches S13c, S13g to be in an OFF state so as not to supply the left outer audio signal LW to the left outer SP terminal 14b, and not to supply the right outer audio signal RW to the right upper SP terminal 14e (S18).
If the combination of the surround rear left audio signal SBL and the surround rear right audio signal SBR is not included in S11, the control unit 2 controls the switches S13a, S13e to be in an OFF state so as not to supply the surround rear left audio signal SBL to the surround rear left SP terminal 14a, and not to supply the surround rear right audio signal SBR to the surround rear right SP terminal 14d (S19). Furthermore, the control unit 2 controls the switches S13c, S13g to be in an OFF state (S19).
Next, the control unit 2 further determines whether or not the combination of the left upper audio signal LH and the right upper audio signal RH is included in the multichannel audio data (S20). If it is included (YES in S20), the control unit 2 controls the switches so as to supply the left upper audio signal LH to the left upper SP terminal 14c, and to supply the right upper audio signal RH to the right upper SP terminal 14f. That is, the control unit 2 controls the switches S13d, S13h to be in an ON state (S21).
On the other hand, if the combination of the left upper audio signal LH and the right upper audio signal RH is not included in S20, the control unit 2 controls the switches S13d, S13h to be in an OFF state so as not to supply the left upper audio signal LH to the left upper SP terminal 14c, and not to supply the right upper audio signal RH to the right upper SP terminal 14f (S22).
Next, the control unit 2 further determines whether or not the combination of the left outer audio signal LW and the right outer audio signal RW is included in the multichannel audio data (S23). If it is included (YES in S23), the control unit 2 controls the switches so as to supply the left outer audio signal LW to the left outer SP terminal 14b, and to supply the right outer audio signal RW to the right outer SP terminal 14e. That is, the control unit 2 controls the switches S13b, S13f to be in an ON state (S24).
If the combination of the left outer audio signal LW and the right outer audio signal RW is not included in S23, the control unit 2 controls the switches S13b, S13f to be in an OFF state so as not to supply the left outer audio signal LW to the left outer SP terminal 14b, and not to supply the right outer audio signal RW to the right outer SP terminal 14e (S25).
As described above, only the two amplifiers 12a, 12b are provided, by which the audio signals of the two channels arbitrarily selected from the surround rear left audio signal SBL, the left outer audio signal LW and the left upper audio signal LH can be amplified to be outputted to the SP terminals corresponding to these channels. Moreover, only the two amplifiers 12c, 12d are provided, by which the audio signals of the two channels arbitrarily selected from the surround rear right audio signal SBR, the right outer audio signal RW and the right upper audio signal RH can be amplified to be outputted to the SP terminals corresponding to these channels. It is because the audio signals of the three channels of the surround rear left audio signal SBL, the left outer audio signal LW, and the left upper audio signal LH are not simultaneously included in the audio formats relating to HD (High Definition) such as Dolby True HD, Dolby Digital Plus, DTS-HD and the like, and the audio signals of the three channels of the surround rear right audio signal SBR, the right outer audio signal RW, and the right upper audio signal RH are not simultaneously included therein that the above-described processing is enabled.
If the surround rear left audio signal SBL, the left outer audio signal LW, and the left upper audio signal LH are simultaneously included, the audio signals of the two channels set by user operation in advance may be amplified to be outputted to the SP terminals of the respective channels. Similarly, if the surround rear right audio signal SBR, the right outer audio signal RW, and the right upper audio signal RH are simultaneously included, the audio signals of the two channels set by user operation in advance may be amplified to be outputted to the SP terminals of the respective channels.
Moreover, while in the above-described flowchart, if the surround rear left audio signal SBL, the left outer audio signal LW, and the left upper audio signal LH are simultaneously included, processing of selecting the surround rear left audio signal SBL and the left upper audio signal LH is performed in default, the present invention is not limited thereto, but the flowchart may be configured so that the left outer audio signal LW is selected. Similarly, while if the surround rear right audio signal SBR, the right outer audio signal RW, and the right upper audio signal RH are simultaneously included, processing of selecting the surround rear right audio signal SBR and the right upper audio signal RH is performed in default, the present invention is not limited thereto, but the flowchart may be configured so that the right outer audio signal RW is selected.
Next, another preferred embodiment of the present invention is described. As shown in FIG. 7, in the embodiment, a circuit configuration may be employed, in which the left outer audio signal LW is replaced by the left upper audio signal LH, and the right outer audio signal RW is replaced by the right upper audio signal RH.
Next, another preferred embodiment of the present invention is described. As shown in FIG. 8, in the embodiment, in place of (or in addition to) the left outer audio signal LW, a left central audio signal LC exists, and in place of (or in addition to) the right outer audio signal RW, a right central audio signal RC exists. The left central audio signal LC is an audio signal reproduced at a position between the left audio signal L and the central audio signal C. The right central audio signal RC is an audio signal reproduced at a position between the right audio signal R and the central audio signal C. In this case, as shown in FIG. 9, a circuit configuration may be employed in which the left outer audio signal LW is replaced by the left central audio signal LC, and the right outer audio signal RW is replaced by the right central audio signal RC.
When the above-described embodiments are generally expressed in light of the foregoing, the surround rear left audio signal SBL is defined as a first extended left audio signal, the surround rear right audio signal SBR is defined as a first extended right audio signal, the left outer audio signal LW is defined as a second extended left audio signal, the right outer audio signal RW is defined as a second extended right audio signal, the left upper audio signal LH is defined as a third extended left audio signal, and the right upper audio signal RH is defined as a third extended right audio signal.
The first extended left audio signal may be any of the surround rear left audio signal SBL, the left outer audio signal LW, the left upper audio signal LH, and the left central audio signal LC. The second extended left audio signal may be any one of the surround rear left audio signal SBL, the left outer audio signal LW, the left upper audio signal LH, and the left central audio signal LC, and may be a channel different from that of the first extended left audio signal. The third extended left audio signal may be any of the surround rear left audio signal SBL, the left outer audio signal LW, the left upper audio signal LH, and the left central audio signal LC, and may be an audio signal of a channel different from those of the first extended left audio signal and the second extended left audio signal.
Similarly, the first extended right audio signal may be any of the surround rear right audio signal SBR, the right outer audio signal RW, the right upper audio signal RH, and the right central audio signal RC. The second extended right audio signal may be any of the surround rear right audio signal SBR, the right outer audio signal RW, the right upper audio signal RH, and the right central audio signal RC, and may be an audio signal of a channel different from that of the first extended right audio signal. The third extended right audio signal may be any of the surround rear right audio signal SBR, the right outer audio signal RW, the right upper audio signal RH, and the right central audio signal RC, and may be an audio signal of a channel different from those of the first extended right audio signal and the second extended right audio signal.
Moreover, what is minimum required for the present invention is at least one of the configuration in which one or two audio signals selected from the first extended left audio signal, the second extended left audio signal, and the third extended left audio signal is (are) amplified, and the configuration in which one or two audio signals selected from the first extended right audio signal, the second extended right audio signal and the third extended right audio signal is (are) amplified. That is, not both the configuration in which the one or two audio signals selected from the first extended left audio signal, the second extended left audio signal and the third extended left audio signal is (are) amplified, and the configuration in which the one or two audio signals selected from first extended right audio signal, the second extended right audio signal and the third extended right audio signal is (are) amplified need to be included.
For example, in the case where only the configuration is included, in which the one or two audio signals selected from the first extended left audio signal, the second extended left audio signal and the third extended left audio signal is (are) amplified, the processing of determining whether or not the combination of the surround rear left audio signal SBL and the surround rear right audio signal SBR is included in each of the above-described flowcharts is changed to processing of determining whether or not the surround rear left audio signal SBL is included. The processing of determining whether or not the combination of the left upper audio signal LH and the right upper audio signal RH is included is changed to processing of determining whether or not the left upper audio signal LH is included. The processing of determining whether or not the combination of the left outer audio signal LW and the right outer audio signal RW is included is changed to processing of determining whether or not the left outer audio signal LW is included.
Next, still another embodiment of the present invention is described. FIG. 10 shows an audio processing unit 5C of the present embodiment. In the present embodiment, while for brief explanation, only the left channels are described, the right channels are similar. A pre-out unit 111 has switches S111a to S111f. The switch S111a performs switching as to whether or not the surround rear left audio signal SBL is to be outputted to an amplifier 112a. The switch S111b performs switching as to whether or not the left outer audio signal LW is to be outputted to the amplifier 112a. The switch S111c performs switching as to whether or not the left central audio signal LC is to be outputted to the amplifier 112a. The switch S111d performs switching as to whether or not the left upper audio signal LH is to be outputted to an amplifier 112b. The switch S111e performs switching as to whether or not the left outer audio signal LW is to be outputted to the amplifier 112b. The switch S111f performs switching as to whether or not the left central audio signal LC is to be outputted to the amplifier 112b. Any one of the switches S111a to S111c is turned ON in accordance with the channel included in the multichannel audio data. Any one of the switches S111d to S111f is turned ON in accordance with the channel included in the multichannel audio data.
The pre-out unit 111 may not include the switches S111a to S111f, but the DSP may change the channels of the audio signals to be supplied to the amplifiers 112a, 112b in accordance with the channels included in the multichannel audio data.
A power amplifier 112 has the amplifiers 112a, 112b. The amplifier 112a amplifies the surround rear left audio signal SBL, the left outer audio signal LW or the left central audio signal LC supplied from the pre-out unit 111 to supply to a SP relay 113 (switches S113a, S113b, S113d). The amplifier 112b amplifies the left upper audio signal LH, the left outer audio signal LW or the left central audio signal LC supplied from the pre-out unit 111 to supply to the SP relay 113 (switches S113c, S113e, S113f).
The SP relay 113 has the relay switches (hereinafter, referred to as switches) S113a to S113f. The switch S113a performs switching as to whether or not the surround rear left audio signal SBL supplied from the amplifier 112a is to be supplied to a surround rear left SP terminal 114a. The switch S113b performs switching as to whether or not the left outer audio signal LW supplied from the amplifier 112a is to be supplied to a left outer SP terminal 114b. The switch S113c performs switching as to whether or not the left outer audio signal LW supplied from the amplifier 112b is to be supplied to the left outer SP terminal 114b. The switch S113d performs switching as to whether or not the left central audio signal LC supplied from the amplifier 112a is to be supplied to a left central SP terminal 114c. The switch S113e performs switching as to whether or not the left central audio signal LC supplied from the amplifier 112b is to be supplied to the left central SP terminal 114c. The switch S113f performs switching as to whether or not the left upper audio signal LH supplied from the amplifier 112b is to be supplied to a left upper SP terminal 114d. The switches S113a to S113f are switched in accordance with the channels included in the multichannel audio data.
A SP terminal 114 has the SP terminals 114a to 114d. The surround rear left speaker SSBL is connected to the surround rear left SP terminal 114a. The left outer speaker SLW is connected to the left outer SP terminal 114b. The left central speaker SLC is connected to the left central SP terminal 114c. The left upper speaker SLH is connected to the left upper SP terminal 114d. 
FIGS. 11 to 13 are flowcharts showing operation of the present embodiment. The control unit 2 determines whether or not the surround rear left audio signal SBL is included in the multichannel audio data (S31). If it is included (YES in S31), the control unit 2 controls the switches so as to supply the surround rear left audio signal SBL to the surround rear left SP terminal 114a. That is, the control unit 2 controls the switches S111a, S113a to be in an ON state, and the switches S111b, S111c, S113b, S113d to be in an OFF state (S32).
The control unit 2 determines whether or not the left upper audio signal LH is included in the multichannel audio data (S33). If it is included (YES in S33), the control unit 2 controls the switches so as to supply the left upper audio signal LH to the left upper SP terminal 114d. That is, the control unit 2 controls the switches S111d, S113f to be in an ON state, and the switches S111e, S111f, S113c, S113e to be in an OFF state (S34).
If the left upper audio signal LH is not included (NO in S33), the control unit 2 determines whether or not the left outer audio signal LW is included in the multichannel audio data (S35). If it is included (YES in S35), the control unit 2 controls the switches so as to supply the left outer audio signal LW to the left outer SP terminal 114b. That is, the control unit 2 controls the switches S111e, S113c to be in an ON state, and the switches S111d, S111f, S113e, S113f to be in an OFF state (S36).
If the left outer audio signal LW is not included (NO in S35), the control unit 2 determines whether or not the left central audio signal LC is included in the multichannel audio data (S37). If it is included (YES in S37), the control unit 2 controls the switches so as to supply the left central audio signal LC to the left central SP terminal 114c. That is, the control unit 2 controls the switches S111f, S113e to be in an ON state, and the switches S111d, S111e, S113c, S113f to be in an OFF state (S38). If the left central audio signal LC is not included (NO in S37), the control unit 2 controls the switches S111d, S111e, S111f, S113c, S113e, S113f to be in an OFF state (S39).
When the surround rear left audio signal SBL is not included in S31 (NO in S31), as shown in FIG. 12, the control unit 2 determines whether or not the left outer audio signal LW is included in the multichannel audio data (S40). If it is included (YES in S40), the control unit 2 controls the switches so as to supply the left outer audio signal LW to the left outer SP terminal 114b. That is, the control unit 2 controls the switches S111b, S113b to be in an ON state, and the switches S111a, S111c, S113a, S113d to be in an OFF state (S41).
The control unit 2 determines whether or not the left upper audio signal LH is included in the multichannel audio data (S42). If it is included (YES in S42), the control unit 2 controls the switches so as to supply the left upper audio signal LH to the left upper SP terminal 114d. That is, the control unit 2 controls the switches S111d, S113f to be in an ON state, and the switches S111e, S111f, S113c, S113e to be in an OFF state (S43).
If the left upper audio signal LH is not included (NO in S42), the control unit 2 determines whether or not the left central audio signal LC is included in the multichannel audio data (S44). If it is included (YES in S44), the control unit 2 controls the switches so as to supply the left central audio signal LC to the left central SP terminal 114c. That is, the control unit 2 controls the switches S111f, S113e to be in an ON state, and the switches S111d, S111e, S113c, S113f to be in an OFF state (S45). If the left central audio signal LC is not included (NO in S44), the control unit 2 controls the switches S111d, S111e, S111f, S113c, S113e, S113f to be in an OFF state (S46).
When the left outer audio signal LW is not included in S40 (NO in S40), as shown in FIG. 13, the control unit 2 determines whether or not the left central audio signal LC is included in the multichannel audio data (S47). If it is included (YES in S47), the control unit 2 controls the switches so as to supply the left central audio signal LC to the left central SP terminal 114c. That is, the control unit 2 controls the switches S111c, S113d to be in an ON state, and the switches S111a, S111b, S113a, S113b to be in an OFF state (S48). If the left central audio signal LC is not included (NO in S47), the control unit 2 controls the switches S111a, S111b, S111c, S113a, S113b, S113d to be in an OFF state (S49).
The control unit 2 determines whether or not the left upper audio signal LH is included in the multichannel audio data (S50). If it is included (YES in S50), the control unit 2 controls the switches so as to supply the left upper audio signal LH to the left upper SP terminal 114d. That is, the control unit 2 controls the switches S111d, S113f to be in an ON state, and the switches S111e, S111f, S113c, S113e to be in an OFF state (S51). If the left upper audio signal LH is not included (NO in S50), the control unit 2 controls the switches S111d, S111e, S111f, S113c, S113e, S113f to be in an OFF state (S52).
Next, still another embodiment of the present invention is described. FIG. 14 shows an audio processing unit 5D of the present embodiment. In the present embodiment, while for brief explanation, only the left channels are described, the right channels are similar. A pre-out unit 211 has switches S211a to S211f. The switch S211a performs switching as to whether or not the surround rear left audio signal SBL is to be outputted to an amplifier 212a. The switch S211b performs switching as to whether or not the left central audio signal LC is to be outputted to the amplifier 212a. The switch S211c performs switching as to whether or not the left outer audio signal LW is to be outputted to an amplifier 212b. The switch S211d performs switching as to whether or not the left central audio signal LC is to be outputted to the amplifier 212b. The switch S211e performs switching as to whether or not the left upper audio signal LH is to be outputted to an amplifier 212c. The switch S211f performs switching as to whether or not the left central audio signal LC is to be outputted to the amplifier 212c. 
A pre-out unit 211 may not include the switches S211a to S211f, but the DSP may change the channels of the audio signals to be supplied to the amplifiers 212a to 212c in accordance with the channels included in the multichannel audio data.
A power amplifier 212 has the amplifiers 212a, 212b, 212c. The amplifier 212a amplifies the surround rear left audio signal SBL or the left central audio signal LC supplied from the pre-out unit 211 to supply to a SP relay 213 (switches S213a, S213c). The amplifier 212b amplifies the left outer audio signal LW or the left central audio signal LC supplied from the pre-out unit 211 to supply to the SP relay 213 (switches S213b, S213d). The amplifier 212c amplifies the left upper audio signal LH or the left central audio signal LC supplied from the pre-out unit 211 to supply to the SP relay 213 (switches S213e, S213f).
The SP relay 213 has the relay switches (hereinafter, referred to as switches) S213a to S213f. The switch S213a performs switching as to whether or not the surround rear left audio signal SBL supplied from the amplifier 212a is to be supplied to a surround rear left SP terminal 214a. The switch S213b performs switching as to whether or not the left outer audio signal LW supplied from the amplifier 212b is to be supplied to a left outer SP terminal 214b. The switch S213c performs switching as to whether or not the left central audio signal LC supplied from the amplifier 212a is to be supplied to a left central SP terminal 214c. The switch S213d performs switching as to whether or not the left central audio signal LC supplied from the amplifier 212b is to be supplied to the left central SP terminal 214c. The switch S213e performs switching as to whether or not the left central audio signal LC supplied from the amplifier 212c is to be supplied to the left central SP terminal 214c. The switch S213f performs switching as to whether or not the left upper audio signal LH supplied from the amplifier 212c is to be supplied to a left upper SP terminal 214d. 
FIGS. 15 to 17 are flowcharts showing operation of the present embodiment. The control unit 2 determines whether or not the surround rear left audio signal SBL is included in the multichannel audio data (S61). If it is included (YES in S61), the control unit 2 controls the switches so as to supply the surround rear left audio signal SBL to the surround rear left SP terminal 214a. That is, the control unit 2 controls the switches S211a, S213a to be in an ON state, and the switches S211b, S213c to be in an OFF state (S62).
The control unit 2 determines whether or not the left outer audio signal LW is included in the multichannel audio data (S63). If it is included (YES in S63), the control unit 2 controls the switches so as to supply the left outer audio signal LW to the left outer SP terminal 214b. That is, the control unit 2 controls the switches S211c, S213b to be in an ON state, and the switches S211d, S213d to be in an OFF state (S64).
The control unit 2 determines whether or not the left upper audio signal LH is included in the multichannel audio data (S65). If it is included (YES in S65), the control unit 2 controls the switches so as to supply the left upper audio signal LH to the left upper SP terminal 214d. That is, the control unit 2 controls the switches S211e, S213f to be in an ON state, and the switches S211f, S213e to be in an OFF state (S66).
If the left upper audio signal LH is not included (NO in S65), the control unit 2 determines whether or not the left central audio signal LC is included in the multichannel audio data (S67). If it is included (YES in S67), the control unit 2 controls the switches so as to supply the left central audio signal LC to the left central SP terminal 214c. That is, the control unit 2 controls the switches S211f, S213e to be in an ON state, and the switches S211e, S213f to be in an OFF state (S68). If the left central audio signal LC is not included (NO in S67), the control unit 2 controls the switches S211e, S211f, S213e, S213f to be in an OFF state (S69).
If the surround rear left audio signal SBL is not included in S61 (NO in S61), as shown in FIG. 16, the control unit 2 determines whether or not the left central audio signal LC is included in the multichannel audio data (S70). If it is included (YES in S70), the control unit 2 controls the switches so as to supply the left central audio signal LC to the left central SP terminal 214c. That is, the control unit 2 controls the switches S211b, S213c to be in an ON state, and the switches S211a, S213a to be in an OFF state (S71). On the other hand, if the left central audio signal LC is not included (NO in S70), the control unit 2 controls the switches S211a, S211b, S213a, S213c to be in an OFF state (S72).
The control unit 2 determines whether or not the left outer audio signal LW is included in the multichannel audio data (S73). If it is included (YES in S73), the control unit 2 controls the switches so as to supply the left outer audio signal LW to the left outer SP terminal 214b. That is, the control unit 2 controls the switches S211c, S213b to be in an ON state, and the switches S211d, S213d to be in an OFF state (S74). If the left outer audio signal LW is not included (NO in S73), the control unit 2 controls the switches S211c, S211d, S213b, S213d to be in an OFF state (S75).
The control unit 2 determines whether or not the left upper audio signal LH is included in the multichannel audio data (S76). If it is included (YES in S76), the control unit 2 controls the switches so as to supply the left upper audio signal LH to the left upper SP terminal 214d. That is, the control unit 2 controls the switches S211e, S213f to be in an ON state, and the switches S211f, S213e to be in an OFF state (S77). If the left upper audio signal LH is not included (NO in S76), the control unit 2 controls the switches S211e, S211f, S213e, S213f to be in an OFF state (S78).
If the left outer audio signal LW is not included in S63 (NO in S63), as shown in FIG. 17, the control unit 2 determines whether or not the left central audio signal LC is included in the multichannel audio data (S79). If it is included (YES in S79), the control unit 2 controls the switches so as to supply the left central audio signal LC to the left central SP terminal 214c. That is, the control unit 2 controls the switches S211d, S213d to be in an ON state, and the switches S211c, S213b to be in an OFF state (S80). On the other hand, if the left central audio signal LC is not included (NO in S79), the control unit 2 controls the switches S211c, S211d, S213b, S213d to be in an OFF state (S81).
The control unit 2 determines whether or not the left upper audio signal LH is included in the multichannel audio data (S82). If it is included (YES in S82), the control unit 2 controls the switches so as to supply the left upper audio signal LH to the left upper SP terminal 214d. That is, the control unit 2 controls the switches S211e, S213f to be in an ON state, and the switches S211f, S213e to be in an OFF state (S83). If the left upper audio signal LH is not included (NO in S82), the control unit 2 controls the switches S211e, S211f, S213e, S213f to be in an OFF state (S84).
Next, still another embodiment of the present invention is described. FIG. 18 shows an audio processing unit 5E of the present embodiment. In the present embodiment, while for brief explanation, only the left channels are described, the right channels are similar. In the present embodiment, as compared with the embodiment in FIG. 4, the audio processing unit 5E further includes a pre-out terminal 15 to output the left outer audio signal LW to the outside of the AV amplifier 1 at the stage before it is supplied to the amplifier 12a or the amplifier 12b. If all of the surround rear left audio signal SBL, the left outer audio signal LW, and the left upper audio signal LH are included in the multichannel audio data, according to the processing in FIGS. 5 and 6, the surround rear left audio signal SBL is amplified in the amplifier 12a to be supplied to the surround rear left SP terminal 14a, and the left upper audio signal LH is amplified in the amplifier 12b to be supplied to the left upper SP terminal 14c. In this case, the left outer audio signal LW is outputted from the pre-out terminal 15. By connecting an amplifier different from the AV amplifier 1 to the pre-out terminal 15, the left outer audio signal LW can be amplified using the other amplifier so that the audio can be outputted from the speaker. As processing, after S4 in FIG. 5, it is determined whether or not the left outer audio signal LW is included in the multichannel audio data, and if it is included, the control is made so that the left outer audio signal LW is outputted from the pre-out terminal 15, and if it is not included, the control is made so that the left outer audio signal LW is not outputted from the pre-out terminal 15.
Next, still another embodiment of the present invention is described. FIG. 19 shows an audio processing unit 5F of the present embodiment. In the present embodiment, while for brief explanation, only the left channels are described, the right channels are similar. In the present embodiment, as compared with the embodiment in FIG. 10, the audio processing unit 5F further includes a pre-out terminal 415 to output the left outer audio signal LW to the outside of the AV amplifier 1 at the stage before it is supplied to the amplifier 112a or the amplifier 112b, and a pre-out terminal 416 to output the left central audio signal LC to the outside of the AV amplifier 1 at the stage before it is supplied to the amplifier 112a or the amplifier 112b. If the surround rear left audio signal SBL, the left outer audio signal LW, and the left upper audio signal LH are included in the multichannel audio data, according to the processing in FIGS. 11 to 13, the surround rear left audio signal SBL is amplified in the amplifier 112a to be supplied to the surround rear left SP terminal 114a, and the left upper audio signal LH is amplified in the amplifier 112b to be supplied to the left upper SP terminal 114d. In this case, the left outer audio signal LW is outputted from the pre-out terminal 415. By connecting an amplifier different from the AV amplifier 1 to the pre-out terminal 415, the left outer audio signal LW can be amplified using the other amplifier so that the audio can be outputted from the speaker.
If the surround rear left audio signal SBL, the left upper audio signal LH, and the left central audio signal LC are included in the multichannel audio data, according to the processing in FIGS. 11 to 13, the surround rear left audio signal SBL is amplified in the amplifier 112a to be supplied to the surround rear left SP terminal 114a, and the left upper audio signal LH is amplified in the amplifier 112b to be supplied to the left upper SP terminal 114d. In this case, the left central audio signal LC is outputted from the pre-out terminal 416. By connecting the amplifier different from the AV amplifier 1 to the pre-out terminal 416, the left central audio signal LC can be amplified using the other amplifier so that the audio can be outputted from the speaker.
If the surround rear left audio signal SBL, the left outer audio signal LW, the left upper audio signal LH, and the left central audio signal LC are included in the multichannel audio data, according to the processing in FIGS. 11 to 13, the surround rear left audio signal SBL is amplified in the amplifier 112a to be supplied to the surround rear left SP terminal 114a, and the left upper audio signal LH is amplified in the amplifier 112b to be supplied to the left upper SP terminal 114d. In this case, the left outer audio signal LW is outputted from the pre-out terminal 415, and the left central audio signal LC is outputted from the pre-out terminal 416. By connecting the amplifier different from the AV amplifier 1 to the pre-out terminals 415, 416, the left outer audio signal LW and the left central audio signal LC can be amplified using the other amplifier so that the audio can be outputted from the speaker.
Next, still another embodiment of the present invention is described. FIG. 20 shows an audio processing unit 5G of the present embodiment. In the present embodiment, while for brief explanation, only the left channels are described, the right channels are similar. In the present embodiment, as compared with the embodiment in FIG. 14, the audio processing unit 5G further includes a pre-out terminal 516 to output the left central audio signal LC to the outside of the AV amplifier 1 at the stage before it is supplied to the amplifier 212a, 212b or 212c. If the surround rear left audio signal SBL, the left outer audio signal LW, the left upper audio signal LH, and the left central audio signal LC are included in the multichannel audio data, according to the processing in FIGS. 15 to 17, the surround rear left audio signal SBL is amplified in the amplifier 212a to be supplied to the surround rear left SP terminal 214a, the left outer audio signal LW is amplified in the amplifier 212b to be supplied to the left outer SP terminal 214b, and the left upper audio signal LH is amplified in the amplifier 212c to be supplied to the left upper SP terminal 214d. In this case, the left central audio signal LC is outputted from the pre-out terminal 516. By connecting an amplifier different from the AV amplifier 1 to the pre-out terminal 516, the left central audio signal LC can be amplified using the other amplifier so that the audio can be outputted from the speaker.
While in the foregoing, the preferred embodiments of the present invention have been described, the present invention is not limited to these embodiments. The present invention may be provided in forms of a program to cause a computer to execute the above-described operation of the AV amplifier and a recording medium that records the same.

## Claims

1. An audio processing apparatus comprising:
a first amplifying unit that amplifies a first extended audio signal or a second extended audio signal, the first extended audio signal being a first extended left audio signal or a first extended right audio signal, and the second extended audio signal being a second extended left audio signal or a second extended right audio signal;
a second amplifying unit that amplifies a second extended audio signal or a third extended audio signal, the third extended audio signal being a third extended left audio signal or a third extended right audio signal;
a first speaker terminal that outputs the first extended audio signal;
a second speaker terminal that outputs the second extended audio signal;
a third speaker terminal that outputs the third extended audio signal;
a first switch that performs switching as to whether or not the first extended audio signal from the first amplifying unit is to be supplied to the first speaker terminal;
a second switch that performs switching as to whether or not the second extended audio signal from the first amplifying unit is to be supplied to the second speaker terminal;
a third switch that performs switching as to whether or not the second extended audio signal from the second amplifying unit is to be supplied to the second speaker terminal;
a fourth switch that performs switching as to whether or not the third extended audio signal from the second amplifying unit is to be supplied to the third speaker terminal;
a channel determining unit that determines which of the first extended audio signal, the second extended audio signal, and the third extended audio signal is included in multichannel audio data; and
a switching control unit that if it is determined that the first extended audio signal is included, causes the first switch to supply the first extended audio signal amplified by the first amplifying unit to the first speaker terminal, if it is determined that the second extended audio signal is included, causes the second switch to supply the second extended audio signal amplified by the first amplifying unit to the second speaker terminal, or causes the third switch to supply the second extended audio signal amplified by the second amplifying unit to the second speaker terminal, and if it is determined that the third extended audio signal is included, causes the fourth switch to supply the third extended audio signal amplified by the second amplifying unit to the third speaker terminal.

2. The audio processing apparatus according to claim 1,
wherein the first extended left audio signal is any of a surround rear left audio signal, a left outer audio signal, a left upper audio signal and a left central audio signal, and the first extended right audio signal is any of a surround rear right audio signal, a right outer audio signal, a right upper audio signal and a right central audio signal,
the second extended left audio signal is any of the surround rear left audio signal, the left outer audio signal, the left upper audio signal and the left central audio signal, and is different from the first extended left audio signal, and the second extended right audio signal is any of the surround rear right audio signal, the right outer audio signal, the right upper audio signal and the right central audio signal, and is different from the first extended right audio signal, and
the third extended left audio signal is any of the surround rear left audio signal, the left outer audio signal, the left upper audio signal and the left central audio signal, and is different from the first extended left audio signal and the second extended left audio signal, and the third extended right audio signal is any of the surround rear right audio signal, the right outer audio signal, the right upper audio signal and the right central audio signal, and is different from the first extended right audio signal and the second extended right audio signal.

3. The audio processing apparatus according to claim 1, wherein if it is determined that the first extended audio signal is not included and that the second extended audio signal is included, the switching control unit causes the second switch to supply the second extended audio signal amplified by the first amplifying unit to the second speaker terminal, and if it is determined that the first extended audio signal is included and that the second extended audio signal is included, the switching control unit causes the third switch to supply the second extended audio signal amplified by the second amplifying unit to the second speaker terminal.

4. The audio processing apparatus according to claim 1,
wherein if it is determined that the first extended audio signal and the second extended audio signal are included, the switching control unit causes the first switch to supply the first extended audio signal amplified by the first amplifying unit to the first speaker terminal, and causes the third switch to supply the second extended audio signal amplified by the second amplifying unit to the second speaker terminal,
if it is determined that the first extended audio signal and the third extended audio signal are included, the switching control unit causes the first switch to supply the first extended audio signal amplified by the first amplifying unit to the first speaker terminal, and causes the fourth switch to supply the third extended audio signal amplified by the second amplifying unit to the third speaker terminal, and
if it is determined that the second extended audio signal and the third extended audio signal are included, the switching control unit causes the second switch to supply the second extended audio signal amplified by the first amplifying unit to the second speaker terminal, and causes the fourth switch to supply the third extended audio signal amplified by the second amplifying unit to the third speaker terminal.

5. The audio processing apparatus according to claims 1, wherein if it is determined that the first extended audio signal, the second extended audio signal, and the third extended audio signal are included, the switching control unit operates so that the two audio signals set by user operation in advance are supplied to the respective corresponding speaker terminals.

6. The audio processing apparatus according to claim 1,
wherein the first amplifying unit amplifies the first extended audio signal, the second extended audio signal, or a fourth extended audio signal, the fourth extended audio signal being a fourth extended left audio signal or a fourth extended right audio signal,
the second amplifying unit amplifies the second extended audio signal, the third extended audio signal or the fourth extended audio signal,
the audio processing apparatus further comprises:
a fourth speaker terminal that outputs the fourth extended audio signal;
a fifth switch that performs switching as to whether or not the fourth extended audio signal from the first amplifying unit is to be supplied to the fourth speaker terminal; and
a sixth switch that performs switching as to whether or not the fourth extended audio signal from the second amplifying unit is to be supplied to the fourth speaker terminal,
the channel determining unit further determines whether or not the fourth extended audio signal is included in the multichannel audio data, and
if it is determined that the fourth extended audio signal is included, the switching control unit causes the fifth switch to supply the fourth extended audio signal amplified by the first amplifying unit to the fourth speaker terminal, or causes the sixth switch to supply the fourth extended audio signal amplified by the second amplifying unit to the fourth speaker terminal.

7. The audio processing apparatus according to claim 6, further comprising:
a first pre-out terminal that outputs the second extended audio signal at a stage before supplying the same to the first amplifying unit or the second amplifying unit; and
a second pre-out terminal that outputs the fourth extended audio signal at the stage before supplying the same to the first amplifying unit or the second amplifying unit,
wherein if it is determined that the first extended audio signal, the second extended audio signal, the third extended audio signal, and the fourth extended audio signal are included, the switching control unit causes the first switch to supply the first extended audio signal amplified by the first amplifying unit to the first speaker terminal, causes the fourth switch to supply the third extended audio signal amplified by the second amplifying unit to the third speaker terminal, causes the second extended audio signal to be outputted from the first pre-out terminal, and causes the fourth extended audio signal to be outputted from the second pre-out terminal.

8. The audio processing apparatus according to claims 1, further comprising a pre-out terminal that outputs the second extended audio signal at a stage before supplying the same to the first amplifying unit or the second amplifying unit, and
if it is determined that the first extended audio signal, the second extended audio signal, and the third extended audio signal are included, the switching control unit causes the first switch to supply the first extended audio signal amplified by the first amplifying unit to the first speaker terminal, causes the fourth switch to supply the third extended audio signal amplified by the second amplifying unit to the third speaker terminal, and causes the second extended audio signal to be outputted from the pre-out terminal.

9. The audio processing apparatus according to claim 1, further comprising:
a third amplifying unit that amplifies the second extended audio signal or a fourth extended audio signal, the fourth extended audio signal being a fourth extended left audio signal or a fourth extended right audio signal;
a fourth speaker terminal that outputs the fourth extended audio signal;
a fifth switch that performs switching as to whether or not the second extended audio signal from the third amplifying unit is to be supplied to the second speaker terminal; and
a sixth switch that performs switching as to whether or not the fourth extended audio signal from the third amplifying unit is to be supplied to the fourth speaker terminal,
wherein the channel determining unit further determines whether or not the fourth extended audio signal is included in the multichannel audio data, and
if it is determined that the second extended audio signal is included, the switching control unit causes the second switch to supply the second extended audio signal amplified by the first amplifying unit to the second speaker terminal, causes the third switch to supply the second extended audio signal amplified by the second amplifying unit to the second speaker terminal, or causes the fifth switch to supply the second extended audio signal amplified by the third amplifying unit to the second speaker terminal, and if it is determined that the fourth extended audio signal is included, the switching control unit causes the sixth switch to supply the fourth extended audio signal amplified by the third amplifying unit to the fourth speaker terminal.

10. The audio processing apparatus according to claim 9, further comprising a pre-out terminal that outputs the second extended audio signal at a stage before supplying the same to the first amplifying unit, the second amplifying unit, or the third amplifying unit, and
if it is determined that the first extended audio signal, the second extended audio signal, the third extended audio signal, and the fourth extended audio signal are included, the switching control unit causes the first switch to supply the first extended audio signal amplified by the first amplifying unit to the first speaker terminal, causes the fourth switch to supply the third extended audio signal amplified by the second amplifying unit to the third speaker terminal, causes the sixth switch to supply the fourth extended audio signal amplified by the third amplifying unit to the fourth speaker terminal, and causes the second extended audio signal to be outputted from the pre-out terminal.