JP3484341B2 - Audio signal transmission device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wideband voice signal transmission apparatus for encoding voice signals of a plurality of channels on a transmission side, multiplex-transmitting to a reception side and decoding.

[0002]

2. Description of the Related Art As a conventional audio signal transmission device, there is, for example, one disclosed in Japanese Patent Application Laid-Open No. 3-163979. This audio signal transmission device uses a variable rate coding system as a coding system in which the information amount of coded data varies according to the property of an input signal, and measures the generated information amount obtained by the coding process. However, it is described that the encoding process is controlled based on the measurement result, and the amount of information generated due to encoding of video signals of multiple channels is controlled to improve the transmission efficiency by multiplexing. .

[0003]

However, in the above-mentioned prior art, it has been described that the amount of information generated accompanying the encoding of video signals of a plurality of channels is controlled to improve the transmission efficiency by multiplexing. This controls the amount of encoded data sent to the transmission line, and does not mention how to efficiently use the processing capacity of the signal processor. Also, as the encoding method,
It is premised on using a variable rate coding method in which the amount of information of coded data varies according to the property of the input signal.
The amount of generated information obtained by the encoding process is measured, and the encoding process is controlled based on the measurement result. The audio signals of multiple channels are divided into multiple bands and encoded transmission. However, if the coding method for each band is based on a fixed speed coding method, the amount of generated information obtained by the coding process for each band does not change, so that the processing capacity of the signal processor is improved. It is impossible to divert it to general use.

The present invention has been made to solve the above problems, and monitors the load of signal processing when a plurality of channels of audio input signals are divided into a plurality of bands and coded for transmission. An object of the present invention is to provide an audio signal transmission device which enables multi-channel encoding and decoding processing even with a signal processor having low processing capability by controlling the encoding processing based on the monitoring.

[0005]

A voice signal transmission apparatus according to the present invention is a band dividing section provided for each channel for dividing a voice input signal of each channel into two bands, a low band side and a high band side. And a low-band encoder provided for each channel that performs coding processing of the low-frequency side signal divided by each of the band division units and calculation of a processing load value, and divided by each band division unit. Used for controlling the high band encoder provided for each channel for coding the high band signal and calculating the processing load value, and for controlling the operation or stop of the coding process of each high band encoder. A switch provided for each channel, a determination unit that determines the operation or stop of the encoding process performed in the high frequency encoder of each channel based on the load monitoring of the encoding process of each channel, and the determination unit Encoding processing stop of the above high frequency encoder If it is determined that is necessary, a switch control unit that performs control to select a switch used to control the operation or stop of the encoding process of the high frequency encoder of each channel and switch to the side that stops the encoding process And a data multiplexing unit for multiplexing the control state of the switch of each channel as switch control information together with encoded data.

Further, the judging unit adds the processing load values calculated by the low band encoder and the high band encoder for each channel, and the code performed by the high band encoder of each channel is added according to the value. It is a processing load measuring unit that determines the operation or stop of the activating process.

Further, the judging unit measures the signal level of the voice input signal of each channel, and judges the operation or stop of the encoding process performed by the high frequency encoder based on the measured value. It is characterized by being.

The determining unit measures the signal level of the signal on the high band side divided by the band dividing unit of each channel, and operates or stops the encoding process performed by the high band encoder according to the value. It is characterized in that it is a signal level measuring unit for judging.

Further, the judging section measures the signal level of the signal on the low frequency side divided by the band dividing section of each channel, and the operation or stop of the encoding process performed by the high frequency encoder according to the value thereof. Is a signal level measuring unit for determining

The determination unit measures the signal level of the high-frequency side signal and the signal level of the low-frequency side signal divided by the band division unit of each channel, and the high-frequency encoder determines the signal level according to the measured value. It is characterized in that it is a signal level measuring unit for judging the operation or stop of the encoding process to be performed.

The determination unit measures the energy value used in the encoding process by the low band encoder of each channel, and determines the operation or stop of the encoding process performed by the high band encoder based on the value. It is an energy value measuring unit that operates.

The determination unit measures the energy value used for the encoding process by the high band encoder and the low band encoder of each channel, and the value of the energy value used in the encoding process performed by the high band encoder is measured by the value. It is characterized in that it is an energy value measuring unit for judging operation or stop.

Further, when it is judged that the information from the judging unit needs to reduce the coding process of the high band encoder, the switch control unit performs the coding process of the high band encoder of each channel. The present invention is characterized in that a switch used for controlling the operation or stop is randomly selected and the selected switch is switched to the side that stops the encoding process.

Further, when it is judged that the information from the judging unit needs to reduce the coding process of the high band encoder, the switch control unit performs the coding process of the high band encoder of each channel. It is characterized in that a switch used for controlling the operation or stop is sequentially selected for each channel, and the selected switch is switched to the side for stopping the encoding process.

Further, when it is determined that the information from the determining unit needs to reduce the encoding process of the high band encoder, the switch control unit performs the encoding process of the high band encoder of each channel. It is characterized in that a switch used for controlling the operation or stop is selected according to a channel selection signal from the outside, and the switch of the channel is controlled to the side where the encoding process is stopped.

A voice signal transmitting apparatus according to another aspect of the present invention includes a data separation unit that receives multiplexed coded data and separates the coded data of each channel into switch control information, and the data separation unit. A low-pass decoder provided for each channel for decoding low-frequency coded data of each channel, and a high-frequency coded data for each channel from the data separation unit A high band decoder provided for each channel, a decoding process selection switch provided for each channel used to control the operation or stop of the decoding process of the high band decoder for each channel, and each high band An interpolation signal generating means provided for each channel for generating an interpolation signal for interpolating the decoded signal at the time of controlling the stop of the decoder, and a decoding signal of either the high frequency decoder or the interpolation signal generating means A decoding signal selection switch provided for each channel that performs selection, a switch control unit that performs switch control of the decoding processing selection switch and the decoding signal selection switch based on switch control information from the data separation unit, A band synthesizing unit provided for each channel for band synthesizing a low band side decoded signal via the low band decoder and a high band side decoded signal via the decoded signal selection switch to generate an output signal. It is equipped with and.

Further, the interpolation signal generating means is a delay buffer for storing the decoded signal of the previous frame decoded by the high band decoder.

Further, the interpolation signal generating means is a mute signal generating section for generating a mute signal and outputting it as a high frequency side decoded signal.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. FIG. 1 is a block diagram of a voice signal transmission device according to a first embodiment of the present invention, which has a configuration in which a two-channel voice signal A and a voice signal B are multi-coded. In FIG. 1, reference numerals 1 and 2 denote a band division unit that divides an input signal into signals in two bands, a low band signal and a high band signal, and 3 and 4 denote encoding processing of the high band signal divided by the band division unit and The high frequency encoders A, 5 and 6 for calculating the processing load amount are the low frequency encoders A and 7 for encoding the low frequency signal divided by the band division unit and calculating the processing load amount. The processing load measurement unit as a determination unit that determines the operation or stop of the encoding process performed in the high frequency encoder of each channel based on the load monitoring of the encoding process measures the total processing load amount of each channel. , And outputs a processing reduction command to the switch control unit 8 according to the result. Further, 8 is a switch control section for controlling the switches 9 and 10 in response to a processing reduction command from the processing load measuring section 7, and 9 and 10 are high frequency encoders A.
3, a switch for controlling the operation and stop of the high frequency encoder A4, and 11 is a data multiplexing unit for multiplexing the coded data of each channel and the switch control information from the switch control unit 8.

Next, the operation will be described. The audio signal A input to the band division unit 1 is divided into signals in two bands, a high band signal and a low band signal, and the high band signal is switched by the switch 9
Then, the low frequency signal is input to the low frequency encoder A5. The switch 9 switches the high frequency signal to the terminal 9a side connected to the high frequency encoder A3 or the terminal 9b side to which nothing is connected according to a switch control command from the switch control unit 8.
When the switch 9 is connected to the terminal 9a side, the high frequency signal is input to the high frequency encoder A3, and the encoding process and the processing load amount are calculated. This encoded data is the data multiplexing unit 1
First, the processing load amount is sent to the processing load measuring unit 7.

Next, an example of a method of calculating the processing load will be given. The encoding process is divided into a plurality of blocks, and the processing load required to process the blocks is measured in advance. In addition, a flag is provided for each block, and when the block is processed in the encoding process, the flag is set. Then, at the end of the encoding process, the state of this flag is checked, and all the processing loads of the flagged blocks are added. When the processing load has been added, remove all flags that were standing.

When the switch 9 is connected to the terminal 9b side, the encoding process and the calculation of the processing load amount in the high frequency encoder A3 are stopped, and the information of the processing load amount 0 is sent to the processing load measuring unit 7. . The low frequency signal is input to the low frequency encoder A5, and the encoding process and the processing load amount are calculated. The encoded data is sent to the data multiplexing unit 11, and the processing load amount is sent to the processing load measuring unit 7. The method of calculating the processing load is the same as the method of calculating the processing load in the high frequency encoder A3 described above, and thus the description thereof will be omitted.

Similarly, the audio signal B input to the band dividing unit 2 is divided into signals in two bands, a high band signal and a low band signal, the high band signal being sent to the switch 10 and the low band signal being low band. It is input to the encoder A6. The switch 10 switches the high frequency signal to the terminal 10a side connected to the high frequency encoder A4 or the terminal 10b side not connected to anything in accordance with the switch control command from the switch control unit 8.

When the switch 10 is connected to the terminal 10a side, the high band signal is input to the high band encoder A4, and the coding process and the processing load amount are calculated. The encoded data is stored in the data multiplexing unit 11, and the processing load is stored in the processing load measuring unit 7.
Sent to. The method of calculating the processing load is the same as the method of calculating the processing load in the high frequency encoder A3 described above.
The description is omitted. When the switch 10 is connected to the terminal 10b side, the encoding process and the calculation of the processing load amount in the high frequency encoder A4 are stopped, and the information of the processing load amount 0 is sent to the processing load measuring unit 7.

The low band signal is input to the low band encoder A6, and the coding process and the processing load amount are calculated. The encoded data is sent to the data multiplexing unit 11, and the processing load amount is sent to the processing load measuring unit 7. The method of calculating the processing load is the same as the method of calculating the processing load in the high frequency encoder A3 described above, and thus the description thereof will be omitted.

The processing load amount sent from the high band encoder A3, the high band encoder A4, the low band encoder A5, and the low band encoder A6 is processed by the processing load measuring unit 7 in the following procedure. The value obtained by adding all the processing loads is compared with a predetermined value. The predetermined value referred to here is, for example, a numerical value of 90% of the processing capacity of the signal processor equipped with the speech coder. If the value obtained by adding all the processing load amounts is smaller than the predetermined value, it is not necessary to reduce the processing in the next frame, and therefore the information without processing reduction is passed to the switch control unit 8. On the other hand, if the value obtained by adding all the processing load amounts is larger than the predetermined value, the processing control information is passed to the switch control unit 8 in order to reduce the processing in the next frame.

Next, the operation of the switch controller 8 will be described. FIG. 2 shows a detailed operation flow of the switch controller 8. The processing is performed in the following procedure. First, it is determined whether or not the information regarding the processing reduction input from the processing load measuring unit 7 is the processing reduction (step 8).
a). If it is determined that there is no processing reduction, the switches 9 and 10 are connected to the terminals 9a and 10a, respectively, in step 8f, and the switches 9 and 10 are connected to the data multiplexing unit 11 in step 8g. The status is sent as switch control information, and the process ends.

On the other hand, when it is determined in step 8a that the processing is reduced, the switch random selection unit in step 8b randomly selects either the switch 9 or the switch 10 to control the stop of the encoding process. Determine the switch to perform.

Next, in step 8c, it is judged whether or not the switch for controlling the stop of the encoding process selected in step 8b is the switch 9, and if it is the switch 9, then in step 8d the switch 9 is selected. Is connected to the terminal 9b side and the switch 10 is connected to the terminal 10a side, the switch connection states of the switch 9 and the switch 10 are sent to the data multiplexing unit 11 as switch control information in step 8g, and the process ends.

On the other hand, if the switch for controlling the processing reduction is not the switch 9, the switch 9 is connected to the terminal 9a side and the switch 10 is connected to the terminal 10b side in step 8e, and the data multiplexing unit 11 is connected in step 8g. Then, the switch connection state of the switch 9 and the switch 10 is sent as the switch control information, and the process ends.

In the data multiplexing unit 11, a switch for sending the high frequency encoded data and low frequency encoded data of the voice signal A and the high frequency encoded data and low frequency encoded data of the voice signal B from the switch control unit 8. It is multiplexed with control information and transmitted.

The details of the processing of the encoding processing section have been described above. By combining this with the decoding processing section of the tenth and eleventh embodiments to be described later, the encoding processing and the processing of the high frequency signal are performed. An audio signal transmission device capable of stopping the calculation of the load value can be realized.

Embodiment 2. Next, FIG. 3 shows a second embodiment.
2 is an example of a detailed flow of a switch control unit 8 of the audio signal transmission device shown in FIG. 1 for explaining the audio signal transmission device according to FIG.

Next, the processing will be described. First,
In step 8a, it is determined whether the information regarding the processing reduction input from the processing load measuring unit 7 indicates the processing reduction. If it is determined that there is no processing reduction, the switches 9 and 10 are connected to the terminals 9a and 10a, respectively, in step 8f, and the switch connection states of the switches 9 and 10 are connected to the data multiplexing unit 11 in step 8g. Is transmitted as the switch control information, and the process ends.

On the other hand, if it is determined in step 8a that the processing has been reduced, it is determined in step 8h whether or not the switch that previously performed the stop control of the encoding process is the switch 9, and if it is the switch 9. In step 8e, the switch 9 is connected to the terminal 9a side and the switch 10 is connected to the terminal 10b side, and in step 8g, the switch connection state of the switch 9 and the switch 10 is sent to the data multiplexing unit 11 as switch control information and processed. To finish.

If the switch that previously controlled the stop of the encoding process was not the switch 9, step 8d
, The switch 9 is connected to the terminal 9b side and the switch 10 is connected to the terminal 10a side.
The switch connection state of the switch 9 and the switch 10 is sent to the switch 1 as switch control information, and the process ends.

The details of the processing of the encoding processing section have been described above. By combining this with the decoding processing section of the tenth and eleventh embodiments to be described later, the encoding processing and the processing of the high frequency signal are performed. An audio signal transmission device capable of stopping the calculation of the load value can be realized.

Further, by using the above method, it is possible to alternately switch the channels for which the coding process is stopped, so that it is possible to disperse the deterioration of the sound quality due to the stop of the coding process of the high frequency signal to both channels. , It is possible to make sound quality deterioration less noticeable.

Embodiment 3. Next, FIG. 4 shows a third embodiment.
The audio signal transmission device according to the present invention will be described in which the switch control unit 8 of the audio signal transmission device shown in FIG. 1 is improved so that a channel selection signal for arbitrarily setting a channel is input from the outside. Further, FIG. 5 is an example of a detailed flow of the switch control unit 8 of the audio signal transmission device according to the third embodiment.

Next, the processing will be described. First,
In step 8a, it is determined whether the processing reduction information input from the processing load measuring unit 7 indicates that processing reduction is present. If it is determined that there is no processing reduction, the switch 9 and the switch 10 are respectively connected to the terminal 9 in step 8f.
a, 10a side, and in step 8g, the switch connection state of the switch 9 and the switch 10 to the data multiplexing unit,
It is transmitted as switch control information, and the process ends.

On the other hand, if it is determined in step 8a that there is a reduction in processing, then in step 8i, the content of the channel selection signal, that is, the setting content of the channel for controlling the stop of the encoding processing is checked, and that channel is checked. If it is the channel of the audio signal B, if it is the channel of the audio signal B, the switch 9 is connected to the terminal 9a side and the switch 10 is connected to the terminal 10b side in step 8e, and the data multiplexing is performed in step 8g. The switch connection state of the switch 9 and the switch 10 is sent to the unit 11 as switch control information, and the process ends.

If the channel for controlling the stop of the encoding process is not the channel of the audio signal B, the switch 9 is switched to the terminal 9b side and the switch 1 is operated in step 8d.
0 is connected to the terminal 10a side, and in step 8g, the switch connection states of the switch 9 and the switch 10 are sent to the data multiplexing unit 11 as switch control information, and the process ends.

The details of the processing of the coding processing section have been described above. By combining this with the decoding processing section of the tenth and eleventh embodiments described later, the coding processing and processing of the high frequency signal are performed. An audio signal transmission device capable of stopping the calculation of the load value can be realized.

Further, by using the above method, it is possible to arbitrarily fix the channel in which the encoding process is stopped.

Fourth Embodiment Next, FIG. 6 shows a block diagram of a voice signal transmission apparatus according to a fourth embodiment of the present invention, and as an example, has a configuration in which a 2-channel voice signal A and a voice signal B are multi-coded. . 6, reference numerals 1, 2, 8 to 11 denote the same parts as those in the first embodiment shown in FIG. 1, and description thereof will be omitted. As a new code, 12 is a signal level as a determination unit that measures the sum of the signal levels of the audio signal A and the audio signal B that are the input signals of each channel, and outputs a processing reduction command to the switch control unit 8 based on the result. The measurement units A, 13, 14 perform encoding processing of the high frequency signal divided by the band division unit, and the high frequency encoders B, 15, 16 perform encoding processing of the low frequency signal divided by the band division unit. It is a low frequency encoder B.

Next, the operation will be described. The audio signal A is input to the signal level measuring unit A12 and the band dividing unit 1. Further, the audio signal B is the signal level measuring unit A12.
Is input to the band division unit 2. Signal level measuring unit A12
Then, the signal level is calculated from the signal of each channel, and the value obtained by adding the level values of all the channels is compared with a predetermined value. The predetermined value here is, for example, 9 which is the maximum level value that can be processed by the audio encoder.
A numerical value of 0%.

The above processing is premised on that there is a correlation between the input signal level and the processing load of the speech coder. That is, it is usual that the processing load of the speech coder increases as the input speech signal level increases. In such a case, the processing load amount is directly calculated as described in the first embodiment. Instead, the processing load amount can be indirectly estimated by measuring the input voice signal level. The maximum level value that the speech coder can process is
It refers to the equivalent signal level value at which it is estimated that the same processing load as that of the signal processor equipped with the speech coder will be obtained.

If the value obtained by adding the level values of all the channels is smaller than the predetermined value, it is not necessary to reduce the processing, and the information without processing reduction is passed to the switch control unit 8. On the other hand, if the value obtained by adding the level values of all channels is larger than the predetermined value,
In order to reduce the processing, the information indicating the processing reduction is passed to the switch control unit 8. The operation of the switch control unit 8 is the same as that described in the description of the first embodiment, the second embodiment, and the third embodiment, and will be omitted.

The voice signal A input to the band division unit 1 is
The signal is divided into two band signals, a high band signal and a low band signal, and the high band signal is input to the switch 9 and the low band signal is input to the low band encoder B15. The switch 9 transmits the high frequency signal to the high frequency encoder B13 according to the switch control command from the switch control unit 8.
To the terminal 9a connected to the terminal 9b or the terminal 9b to which nothing is connected.

When the switch is connected to the terminal 9a side,
The high frequency signal is input to the high frequency encoder B13 and is encoded. In addition, the encoded data is the data multiplexing unit 11
Sent to. On the other hand, when the switch is connected to the terminal 9b side, the encoding process in the high frequency encoder B13 is stopped. The low frequency signal is input to the low frequency encoder B15, and is encoded. Further, the encoded data is sent to the data multiplexing unit 11.

The voice signal B input to the band division unit 2 is
It is divided into two band signals, a high band signal and a low band signal. The high band signal is sent to the switch 10 and the low band signal is put to the low band encoder B16.
Entered in. The switch 10 transmits the high frequency signal to the high frequency encoder B according to the switch control command from the switch control unit 8.
14 is switched to the terminal 10a side connected to the terminal 14 or the terminal 10b side to which nothing is connected.

When the switch 10 is connected to the terminal 10a side, the high frequency signal is input to the high frequency encoder B14 and the encoding process is performed. Further, the encoded data is sent to the data multiplexing unit 11. On the other hand, when the switch 10 is connected to the terminal 10b side, the encoding process in the high frequency encoder B14 is stopped. The low frequency signal is input to the low frequency encoder B16 and is encoded. Further, the encoded data is sent to the data multiplexing unit 11.

In the data multiplexing unit 11, a switch for sending the high frequency encoded data and low frequency encoded data of the voice signal A and the high frequency encoded data and low frequency encoded data of the voice signal B from the switch control unit 8. It is multiplexed with control information and transmitted.

The details of the processing of the encoding processing section have been described above. By combining this with the decoding processing section of the tenth and eleventh embodiments described later, the encoding processing of the high frequency signal is stopped. It is possible to realize an audio signal transmission device capable of performing.

Further, by using the above method, the processing load amount can be easily estimated based on the input audio signal level, instead of directly calculating the processing load amount.

Embodiment 5. Next, FIG. 7 shows a block diagram of an audio signal transmission apparatus according to Embodiment 5 of the present invention, and as an example, has a configuration in which an audio signal A and an audio signal B of two channels are multi-coded. . In FIG. 7, reference numerals 1, 2 and 8 to 11 denote the same parts as those of the first embodiment shown in FIG. Also, 13 to 16
Indicates the same parts as those in the fourth embodiment shown in FIG. 6, and the description thereof will be omitted. As a new code, 17 is the band division unit 1.
And the signal level measuring unit B as a determining unit that measures the total signal level of the high frequency signals of the respective channels divided by the band dividing unit 2 and issues a processing reduction command to the switch control unit 8 according to the result.

Next, the operation will be described. The audio signal A input to the band division unit 1 is divided into signals in two bands, a high band signal and a low band signal, the high band signal being supplied to the signal level measuring unit B17 and the switch 9, and the low band signal being low band. It is input to the encoder B15.

The voice signal B input to the band division unit 2 is
It is divided into a signal in two bands, a high band signal and a low band signal, and the high band signal is a signal level measuring unit B17 and a switch 10.
Then, the low frequency signal is input to the low frequency encoder B16.

The signal level measuring section B17 calculates the signal level from the high frequency signal of each channel, and compares the value obtained by adding the level values of all channels with a predetermined value. The predetermined value referred to here is the maximum level value that can be processed by the high band encoder B13 and the high band encoder 14,
For example, it refers to a numerical value of 90%.

If the value obtained by adding the level values of all channels is smaller than a predetermined value, it is not necessary to reduce the processing, and therefore the information without processing reduction is passed to the switch control section 8. On the other hand, if the value obtained by adding the level values of all channels is larger than the predetermined value,
In order to reduce the processing, the information indicating the processing reduction is passed to the switch control unit 8. The operation of the switch control unit 8 is the same as that described in the description of the first, second and third embodiments, and will be omitted.

The switch 9 sends the high frequency signal to the high frequency encoder B13 in accordance with the switch control command from the switch control unit 8.
To the terminal 9a connected to the terminal 9b or the terminal 9b to which nothing is connected. When the switch 9 is connected to the terminal 9a side, the high frequency signal is input to the high frequency encoder B13,
Encoding processing is performed. Further, the encoded data is sent to the data multiplexing unit 11. On the other hand, switch 9 has terminal 9b
If it is connected to the side, the encoding process in the high frequency encoder B13 is stopped. The low frequency signal is input to the low frequency encoder B15, and is encoded. Further, the encoded data is sent to the data multiplexing unit 11.

The switch 10 transmits the high frequency signal to the high frequency encoder B1 according to the switch control command from the switch control unit 8.
4 is switched to the terminal 10a side connected to No. 4 or the terminal 10b side to which nothing is connected. Switch 10 is terminal 10
When the signal is connected to the a side, the high frequency signal is input to the high frequency encoder B14 to be encoded. Further, the encoded data is sent to the data multiplexing unit 11. On the other hand, switch 1
If 0 is connected to the terminal 10b side, the high frequency encoder B1
The encoding process in 4 is stopped. The low frequency signal is input to the low frequency encoder B16 and is encoded. Also,
The encoded data is sent to the data multiplexing unit 11.

In the data multiplexer 11, a switch for sending the high frequency encoded data and low frequency encoded data of the voice signal A and the high frequency encoded data and low frequency encoded data of the voice signal B from the switch controller 8. It is multiplexed with control information and transmitted.

The details of the processing of the encoding processing unit have been described above. By combining this with the decoding processing unit of the tenth and eleventh embodiments described later, the encoding processing of the high frequency signal is stopped. It is possible to realize an audio signal transmission device capable of performing.

Further, by using the above method, it is possible to easily estimate the processing load amount based on the input audio signal level instead of directly calculating the processing load amount.

Sixth Embodiment Next, FIG. 8 shows a block diagram of an audio signal transmission apparatus according to Embodiment 6 of the present invention, and as an example, has a configuration in which an audio signal A and an audio signal B of two channels are multi-coded. . In FIG. 8, reference numerals 1, 2, and 8 to 11 indicate the same parts as those in the first embodiment shown in FIG. 1, and the description thereof will be omitted. Also, 13 to 16
Indicates the same parts as those in the fourth embodiment shown in FIG. 6, and the description thereof will be omitted. As a new code, 18 is the band division unit 1
And the signal level measuring unit C as a determining unit that measures the total signal level of the low-frequency signals of each channel divided by the band dividing unit 2 and issues a processing reduction command to the switch control unit 8 according to the result.

Next, the operation will be described. The audio signal A input to the band division unit 1 is divided into signals in two bands, a high band signal and a low band signal, and the high band signal is switched by the switch 9
Then, the low frequency signal is input to the signal level measuring unit C18 and the low frequency encoder B15. The audio signal B input to the band division unit 2 is divided into signals of two bands, a high band signal and a low band signal, the high band signal is fed to the switch 10, and the low band signal is fed to the signal level measuring unit C18 and the low band signal. It is input to the encoder B16.

The signal level measuring section C18 calculates the signal level from the low frequency signal of each channel, and compares the value obtained by adding the level values of all channels with a predetermined value. The predetermined value here means a numerical value of, for example, 90% of the maximum level value that can be processed by the low band encoder B15 and the low band encoder B16.

If the value obtained by adding the level values of all the channels is smaller than the predetermined value, it is not necessary to reduce the processing, and therefore the information without processing reduction is passed to the switch control section 8. On the other hand, if the value obtained by adding the level values of all channels is larger than the predetermined value,
Since it is necessary to reduce the processing, the information indicating that the processing is reduced is passed to the switch control unit 8. The operation of the switch control unit 8 is the same as that described in the description of the first embodiment, the second embodiment, and the third embodiment, and will be omitted.

The switch 9 transmits the high frequency signal to the high frequency encoder B13 according to the switch control command from the switch control section 8.
To the terminal 9a connected to the terminal 9b or the terminal 9b to which nothing is connected. When the switch 9 is connected to the terminal 9a side, the high frequency signal is input to the high frequency encoder B13,
Encoding processing is performed. Further, the encoded data is sent to the data multiplexing unit 11. On the other hand, switch 9 has terminal 9b
If it is connected to the side, the encoding process in the high frequency encoder B13 is stopped.

The low frequency signal is input to the low frequency encoder B15,
Encoding processing is performed. Further, the encoded data is sent to the data multiplexing unit 11. The switch 10 switches the high frequency signal to the terminal 10a side connected to the high frequency encoder B14 or the terminal 10b side to which nothing is connected according to the switch control command from the switch control unit 8. Switch 1
When 0 is connected to the terminal 10a side, the high frequency signal is input to the high frequency encoder B14 and the encoding process is performed. Also,
The encoded data is sent to the data multiplexing unit 11. On the other hand, when the switch 10 is connected to the terminal 10b side,
The encoding process in the high frequency encoder B14 is stopped.

The low frequency signal is input to the low frequency encoder B16,
Encoding processing is performed. Further, the encoded data is sent to the data multiplexing unit 11. In the data multiplexing unit 11, the high frequency encoded data and the low frequency encoded data of the voice signal A and the high frequency encoded data and the low frequency encoded data of the voice signal B are sent together with the switch control information sent from the switch control unit 8. Multiplex and transmit.

The details of the processing of the encoding processing section have been described above. By combining this with the decoding processing section of the tenth and eleventh embodiments described later, the encoding processing of the high frequency signal is stopped. It is possible to realize an audio signal transmission device capable of performing.

Further, by using the above method, the processing load amount can be easily estimated based on the input audio signal level, instead of directly calculating the processing load amount.

Embodiment 7. Next, FIG. 9 shows a seventh embodiment.
2 is a block diagram of an audio signal transmission apparatus according to the present invention, and has a configuration in which audio signals A and B of two channels are multi-coded as an example. In FIG. 9, 1,
Reference numerals 2, 8 to 11 denote the same parts as those in the first embodiment shown in FIG. 1, and the description thereof will be omitted. Further, 13 to 16 are shown in FIG.
The same parts as those of the fourth embodiment shown in FIG. As a new code, 19 measures the total signal level of the high band signal and the low band signal of each channel divided by the band division unit 1 and the band division unit 2, and the switch control unit 8 reduces the processing according to the result. The signal level measurement unit D is a determination unit that issues a command.

Next, the operation will be described. The audio signal A input to the band division unit 1 is divided into signals in two bands, a high band signal and a low band signal, the high band signal is fed to the signal level measuring unit D19 and the switch 9, and the low band signal is fed to the signal level. It is input to the measurement unit D19 and the low frequency encoder B15.

The voice signal B input to the band division unit 2 is
The signal is divided into two band signals, a high band signal and a low band signal, and the high band signal is fed to the signal level measuring unit D19 and the switch 10.
The low frequency signal is obtained by the signal level measuring unit D19 and the low frequency encoder B1.
6 is input.

The signal level measuring section D19 calculates the signal level from the low band signal and the high band signal of each channel, and compares the value obtained by adding the level values of all channels with a predetermined value. The predetermined value here means a numerical value of, for example, 90% of the maximum level value that can be processed by the high band encoder B13, the high band encoder B14, the low band encoder B15, and the low band encoder B16.

If the value obtained by adding the level values of all the channels is smaller than the predetermined value, it is not necessary to reduce the processing, and therefore the information without processing reduction is passed to the switch control section 8. On the other hand, if the value obtained by adding the level values of all channels is larger than the predetermined value,
In order to reduce the processing, the information indicating the processing reduction is passed to the switch control unit 8. The operation of the switch control unit 8 is the same as that described in the description of the first embodiment, the second embodiment, and the third embodiment, and will be omitted.

The switch 9 sends the high frequency signal to the high frequency encoder B13 according to the switch control command from the switch control unit 8.
To the terminal 9a connected to the terminal 9b or the terminal 9b to which nothing is connected. When the switch 9 is connected to the terminal 9a side, the high frequency signal is input to the high frequency encoder B13,
Encoding processing is performed. Further, the encoded data is sent to the data multiplexing unit 11. On the other hand, switch 9 has terminal 9b
If it is connected to the side, the encoding process in the high frequency encoder B13 is stopped.

The low frequency signal is input to the low frequency encoder B15,
Encoding processing is performed. Further, the encoded data is sent to the data multiplexing unit 11. The switch 10 switches the high frequency signal to the terminal 10a side connected to the high frequency encoder B14 or the terminal 10b side to which nothing is connected according to the switch control command from the switch control unit 8. Switch 1
When 0 is connected to the terminal 10a side, the high frequency signal is input to the high frequency encoder B14 and the encoding process is performed. Also,
The encoded data is sent to the data multiplexing unit 11. On the other hand, when the switch 10 is connected to the terminal 10b side,
The encoding process in the high frequency encoder B14 is stopped.

The low frequency signal is input to the low frequency encoder B16,
Encoding processing is performed. Further, the encoded data is sent to the data multiplexing unit 11. In the data multiplexing unit 11, the high frequency encoded data and low frequency encoded data of the audio signal A and the high frequency encoded data and low frequency encoded data of the audio signal B are sent together with the switch control information transmitted from the switch control unit 8. Multiplex and transmit.

The details of the processing of the encoding processing section have been described above. By combining this with the decoding processing section of the tenth and eleventh embodiments described later, the encoding processing of the high frequency signal is stopped. It is possible to realize an audio signal transmission device capable of performing.

By using the above method, the processing load amount can be easily estimated based on the input audio signal level instead of directly calculating the processing load amount.

Eighth Embodiment In the above-described fourth to seventh embodiments, the signal level value is measured and the process reduction control is performed based on the measured value. However, the same process as the signal level value measurement is performed as a process inside the encoder. If included, it may be used.

FIG. 10 shows a block diagram of an audio signal transmitting apparatus according to the eighth embodiment. As an example, 2
The audio signal A and the audio signal B of the channel are multiplexed and encoded. In FIG. 10, 1, 2, 8-11
Indicates the same parts as those in the first embodiment shown in FIG. 1, and the description thereof will be omitted. Further, 13 and 14 indicate the same parts as those in the fourth embodiment shown in FIG. 6, and the description thereof will be omitted. As a new code, 20 is a low band encoder C21 and a low band encoder C.
The energy value measurement units A, 21 and 22 as the determination units that measure the energy value sent from 22 and issue a processing reduction command to the switch control unit 8 according to the result are low-frequency signals divided by the band division unit. It is a low-band encoder C that performs the encoding process of 1 and the transmission of energy values. The energy value here means a value obtained by squaring the input signal used in the audio encoding process.

Next, the operation will be described. The audio signal A input to the band division unit 1 is divided into signals in two bands, a high band signal and a low band signal, and the high band signal is switched by the switch 9
Then, the low frequency signal is input to the low frequency encoder C21.

The switch 9 sends the high frequency signal to the high frequency encoder B13 in accordance with the switch control command from the switch control unit 8.
To the terminal 9a connected to the terminal 9b or the terminal 9b to which nothing is connected. When the switch 9 is connected to the terminal 9a side, the high frequency signal is input to the high frequency encoder B13,
Encoding processing is performed. Further, the encoded data is sent to the data multiplexing unit 11. On the other hand, switch 9 has terminal 9b
If it is connected to the side, the encoding process in the high frequency encoder B13 is stopped.

The low frequency signal is input to the low frequency encoder C21,
Encoding processing and transmission of energy values are performed. Also,
The encoded data is sent to the data multiplexing unit 11, and the energy value is sent to the energy value measuring unit A20. Band division unit 2
The audio signal B input to is divided into two band signals, a high band signal and a low band signal, and the high band signal is input to the switch 10.
The low frequency signal is input to the low frequency encoder C22.

The switch 10 sends the high frequency signal to the high frequency encoder B1 in accordance with the switch control command from the switch control unit 8.
4 is switched to the terminal 10a side connected to No. 4 or the terminal 10b side to which nothing is connected. When the switch is connected to the side of 10a, the high frequency signal is input to the high frequency encoder B14, and the encoding process is performed. Further, the encoded data is sent to the data multiplexing unit 11. On the other hand, the switch is 10b
If it is connected to the side, the encoding process in the high frequency encoder B14 is stopped.

The low frequency signal is input to the low frequency encoder C21,
Encoding processing and transmission of energy values are performed. Also,
The encoded data is sent to the data multiplexing unit 11, and the energy value is sent to the energy value measuring unit A20. Low frequency encoder C
21, the energy value sent from the low frequency encoder C22 is processed by the energy value measuring unit A20 in the following procedure.

The value obtained by adding all the energy values is compared with a predetermined value. The predetermined value referred to here is, for example, a numerical value of 90% of the maximum energy value that can be processed by the low band encoder C21 and the low band encoder C22. If the value obtained by adding all the energy values is smaller than the predetermined value, it is not necessary to reduce the processing, and therefore the information without the processing reduction is passed to the switch control unit 8. On the other hand, when the value obtained by adding all the energy values is larger than the predetermined value, the processing control information is passed to the switch control unit 8 in order to reduce the processing.
The operation of the switch control unit 8 is the same as that described in the description of the first, second and third embodiments, and will be omitted.

In the data multiplexing unit 11, a switch for sending the high frequency encoded data and low frequency encoded data of the voice signal A and the high frequency encoded data and low frequency encoded data of the voice signal B from the switch control unit 8. It is multiplexed with control information and transmitted.

The details of the processing of the encoding processing section have been described above. However, by combining this with the decoding processing section of the tenth and eleventh embodiments described later, the encoding processing of the high frequency signal is stopped. It is possible to realize an audio signal transmission device capable of performing.

By using the above method, the processing load inside the encoder can be effectively used to easily estimate the processing load amount.

Ninth Embodiment Next, FIG. 11 shows a block diagram of an audio signal transmission apparatus according to the ninth embodiment, and as an example, has a configuration in which audio signals A and audio signals B of two channels are multi-coded. In FIG. 10, reference numerals 1, 2, and 8 to 11 indicate the same parts as those in the first embodiment shown in FIG. 1, and the description thereof will be omitted. Also 21,22
Indicates the same parts as those of the eighth embodiment shown in FIG. 10, and the description thereof will be omitted. As a new code, 25 measures the energy value transmitted from the high band encoder C23, the high band encoder C24, the low band encoder C21, and the low band encoder C22, and the switch controller 8 processes the energy value according to the result. Energy value measuring units B, 23, and 24 serving as determination units that output reduction commands are high-frequency encoders that perform encoding processing of high-frequency signals divided by the band division unit and transmission of energy values used in the encoding processing. It is C.

Next, the operation will be described. The audio signal A input to the band division unit 1 is divided into two band signals, a high band signal and a low band signal, and the high band signal is switched by the switch 9
Then, the low frequency signal is input to the low frequency encoder C21.

The switch 9 sends the high frequency signal to the high frequency encoder C23 in accordance with the switch control command from the switch control unit 8.
To the terminal 9a connected to the terminal 9b or the terminal 9b to which nothing is connected. When the switch 9 is connected to the terminal 9a side, the high frequency signal is input to the high frequency encoder C23,
Encoding processing and transmission of energy values are performed. Also,
The encoded data is sent to the data multiplexing unit 11, and the energy value is sent to the energy value measuring unit B25. On the other hand, when the switch 9 is connected to the terminal 9b side, the high frequency encoder C2
3, the encoding process and the transmission of the energy value are stopped, and the information of the energy value 0 is transferred to the energy value measuring unit B25.
Send to.

The low frequency signal is input to the low frequency encoder C21,
Encoding processing and transmission of energy values are performed. The coded data is sent to the data multiplexing unit 11, and the energy value is sent to the energy value measuring unit B25.

The voice signal B input to the band division unit 2 is
It is divided into two band signals, a high band signal and a low band signal. The high band signal is sent to the switch 10 and the low band signal is put to the low band encoder C22.
Entered in.

The switch 10 sends the high frequency signal to the high frequency encoder C2 in accordance with the switch control command from the switch control unit 8.
4 is switched to the terminal 10a side connected to No. 4 or the terminal 10b side to which nothing is connected. Switch 10 is terminal 10
When connected to the a side, the high frequency signal is input to the high frequency encoder C24, and the encoding process and the transmission of the energy value are performed. The coded data is sent to the data multiplexing unit 11, and the energy value is sent to the energy value measuring unit B25. On the other hand, when the switch 10 is connected to the terminal 10b side,
The encoding process and the transmission of the energy value in the high frequency encoder C24 are stopped, and the information of the energy value 0 is transmitted to the energy value measuring unit B25.

The low frequency signal is input to the low frequency encoder C22,
Encoding processing and transmission of energy values are performed. The coded data is sent to the data multiplexing unit 11, and the energy value is sent to the energy value measuring unit B25.

The energy values sent from the high frequency encoder C23, the high frequency encoder C24, the low frequency encoder C21 and the low frequency encoder C22 are processed in the energy value measuring unit B25 in the following procedure.

A value obtained by adding all energy values is compared with a predetermined value. Here, the predetermined value refers to, for example, a numerical value of 90% of the maximum energy value that can be processed by the high band encoder C23, the high band encoder C24, the low band encoder C21, and the low band encoder C22. If the value obtained by adding all the energy values is smaller than the predetermined value, it is not necessary to reduce the processing, and therefore the information without the processing reduction is passed to the switch control unit 8. On the other hand, if the value obtained by adding all the energy values is larger than the predetermined value, it is necessary to reduce the processing, and therefore the information indicating that the processing has been reduced is passed to the switch control unit 8. The operation of the switch control unit 8 is the same as that described in the description of the first embodiment, the second embodiment, and the third embodiment, and will be omitted.

In the data multiplexing unit 11, a switch for sending the high frequency encoded data and low frequency encoded data of the audio signal A and the high frequency encoded data and low frequency encoded data of the audio signal B from the switch control unit 8. It is multiplexed with control information and transmitted.

The details of the processing of the encoding processing unit have been described above. However, by combining this with the decoding processing unit of the tenth and eleventh embodiments described later, the encoding processing of the high frequency signal is stopped. It is possible to realize an audio signal transmission device capable of performing.

By using the above method, the processing load inside the encoder can be effectively used to easily estimate the processing load amount.

Embodiment 10. Next, FIG. 12 shows a block diagram of an audio signal transmitting apparatus according to the tenth embodiment, and as an example, it is configured to separate two-channel multiplexed encoded data and perform a decoding process. There is.
In FIG. 12, reference numeral 27 denotes a data separation unit that separates the multiplexed data into encoded data of each channel and a switch control signal, and 28 receives the switch control information from the data separation unit 27 and switches 29, 30, Switch 3
7, a switch controller for controlling the switch 38, 29,
Denoted at 30 is a decoding process selection switch for controlling the operation and stop of the high band decoder 33 and the high band decoder 34, and 31, 32, respectively.
Is a delay buffer as interpolation signal generating means for storing the decoded signal of the current frame from the high band decoder 33 and the high band decoder 34 and sending the decoded signal of the previous frame to the switch 37 and the switch 38, respectively, Reference numeral 34 denotes a high band decoder that decodes the encoded data on the high band side and sends the decoded signals to the delay buffer 31 and the switch 37, the delay buffer 32 and the switch 38, and 35 and 36 denote the coded data on the low band side. The band synthesizing unit 3
9, low-band decoders 37, 38 for sending to the band synthesizer 40
Is a decoded signal selection switch for selecting a decoded signal, 39, 4
Reference numeral 0 is a band synthesizing unit for synthesizing decoded signals on the high band side and the low band side of each channel.

Next, the operation will be described. The multiplexed data input from the transmission line to the data separating unit 27 is separated into high band encoded data, low band encoded data, and switch control information of each channel, and the high band encoded data is sent to the switches 29 and 30. The low band encoded data is input to the low band decoder 35 and the low band decoder 36, and the switch control information is input to the switch control unit 28.

In the switch control unit 28, the data separation unit 2
When the switch control information is received from the switch control terminal 7 and the content of the switch control information is the stop of the decoding process of the channel on the switch 29 side, the switch 29 is connected to the terminal 29a side and the switch 30 is connected to the terminal 30b.
Side, the switch 37 is connected to the terminal 37a side, and the switch 38 is connected to the terminal 38b side. When the decoding process of the channel on the switch 30 side is stopped, the switch 29 is set to the terminal 2
9b side, the switch 30 is connected to the terminal 30a side, the switch 37 is connected to the terminal 37b side, and the switch 38 is connected to the terminal 38a side. If the decoding process is not stopped on both channels, the switch 29 and the switch 30 are respectively connected to the terminal 29.
The switches 37 and 38 are set to the terminals 37b and 38b, respectively, on the sides b and 30b.

When the switch 29 is connected to the terminal 29b, the high band decoder 33 decodes the input high band coded data and sends the decoded signal to the delay buffer 31 and the switch 37. The delay buffer 31 sends the stored decoded signal of the previous frame to the switch 37, and then stores the decoded signal of the current frame from the high frequency decoder 33. At this time, since the switch 37 is connected to the terminal 37b side under the control of the switch control unit 28, the decoded signal of the current frame is sent to the band synthesizing unit 39 as the decoded signal on the high frequency side.

When the switch 29 is connected to the terminal 29a, the high frequency decoder 33 stops the decoding process and the output of the decoded signal to the delay buffer 31. At this time, since the switch 37 is connected to the terminal 37a side under the control of the switch control unit 28, the decoded signal of the previous frame from the delay buffer 31 becomes the decoded signal of the high frequency band and the band synthesis unit 39.
Sent to.

The low band decoder 35 performs a decoding process on the input low band side coded data, and outputs the decoded signal to the band synthesizing section 39.
Send to. The band synthesizing unit 39 synthesizes the decoded signal on the high band side and the decoded signal on the low band side, and sends it as an output signal.

When the switch 30 is connected to the terminal 30b, the high frequency decoder 34 decodes the input high frequency encoded data and sends the decoded signal to the delay buffer 32 and the switch 38. The delay buffer 32 sends the stored decoded signal of the previous frame to the switch 38, and then stores the decoded signal of the current frame from the high frequency decoder 34. At this time, since the switch 38 is connected to the terminal 38b side under the control of the switch control unit 28, the decoded signal of the current frame is converted into the decoded signal on the high frequency side as the band synthesizing unit 40.
Sent to.

When the switch 30 is connected to the terminal 30a, the high frequency decoder 34 stops the decoding process and the output of the decoded signal to the delay buffer 32. At this time, since the switch 38 is connected to the terminal 38a side under the control of the switch control unit 28, the decoded signal of the previous frame from the delay buffer 32 becomes the decoded signal of the high frequency band and the band synthesis unit 40.
Sent to.

The low band decoder 36 decodes the input coded data on the low band side, and outputs the decoded signal to the band synthesizing section 40.
Send to. The band synthesizing unit 40 synthesizes the decoded signal on the high band side and the decoded signal on the low band side, and sends it as an output signal.

The details of the processing of the decoding processing section have been described above. However, by combining this with the encoding processing section of the first to ninth embodiments described above, the decoding processing of the high frequency signal is stopped. It is possible to realize an audio signal transmission device capable of performing.

If the above method is used, the high frequency decoder 3
3 or the loss of the decoded signal due to the stop of the high frequency encoder 34 can be interpolated by the decoded signal of the previous frame, so that the deterioration of the voice quality can be reduced.

Eleventh Embodiment Next, FIG. 13 shows a block diagram of an audio signal transmitting apparatus according to the eleventh embodiment, and as an example, it is configured to separate two-channel multiplexed encoded data and perform a decoding process. . Figure 1
In FIG. 3, 27 to 30 and 33 to 40 are the same parts as those of the tenth embodiment shown in FIG. 12, so the same reference numerals are given and the description thereof is omitted. As new codes, 41 and 42 are mute signal generation units as interpolation signal generation units that generate mute signals and output them as decoded signals on the high frequency side.

Next, the operation will be described. The multiplexed data input from the transmission line to the data separation unit 27 is separated into high band encoded data, low band encoded data, and switch control information of each channel, and the high band encoded data is sent to the switches 29 and 30. The low band encoded data is input to the low band decoder 35 and the low band decoder 36, and the switch control information is input to the switch control unit 28.

In the switch controller 28, the data separator 2
When the switch control information is received from the switch control terminal 7 and the content of the switch control information is the stop of the decoding process of the channel on the switch 29 side, the switch 29 is connected to the terminal 29a side and the switch 30 is connected to the terminal 30b.
Side, the switch 37 is connected to the terminal 37a side, and the switch 38 is connected to the terminal 38b side. When the decoding process of the channel on the switch 30 side is stopped, the switch 29 is set to the terminal 2
9b side, the switch 30 is connected to the terminal 30a side, the switch 37 is connected to the terminal 37b side, and the switch 38 is connected to the terminal 38a side. If the decoding process is not stopped for both channels, the switch 29 and the switch 30 are respectively connected to the terminal 29.
The switches 37 and 38 are set to the terminals b and 30b, respectively, and the switches 37 and 38 are set to the terminals 37b and 38b, respectively.

When the switch 29 is connected to the terminal 29b, the high band decoder 33 performs a decoding process of the input high band encoded data and sends a decoded signal to the switch 37. The mute signal generator 41 switches the mute signal to the switch 37.
Send to. At this time, the switch 37 is the switch controller 2
Since it is connected to the terminal 37b side by the control of 8, the decoded signal of the current frame is sent to the band synthesizing unit 39 as a decoded signal on the high frequency side.

When the switch 29 is connected to the terminal 29a, the high frequency decoder 33 stops the decoding process. At this time, since the switch 37 is connected to the terminal 37a side under the control of the switch controller 28, the mute signal from the mute signal generator 41 is sent to the band synthesizer 39 as a decoded signal on the high frequency side.

The low band decoder 35 performs a decoding process on the input low band side coded data, and outputs the decoded signal to the band division unit 39.
Send to. The band synthesizing unit 39 synthesizes the decoded signal on the high band side and the decoded signal on the low band side, and sends it as an output signal.

When the switch 30 is connected to the terminal 30b, the high band decoder 34 decodes the input high band encoded data and sends the decoded signal to the switch 38. The mute signal generator 42 switches the mute signal to the switch 38.
Send to. At this time, the switch 38 is the switch controller 2
Since it is connected to the terminal 38b side under the control of 8, the decoded signal of the current frame is sent to the band synthesizing unit 40 as a decoded signal on the high frequency side.

When the switch 30 is connected to the terminal 30a, the high frequency decoder 34 stops the decoding process. At this time, since the switch 38 is connected to the terminal 38a side under the control of the switch controller 28, the mute signal from the mute signal generator 42 is sent to the band synthesizer 40 as a decoded signal on the high frequency side.

The low-band decoder 36 decodes the input low-band side coded data, and outputs the decoded signal to the band division unit 40.
Send to. The band synthesizing unit 40 synthesizes the decoded signal on the high band side and the decoded signal on the low band side, and sends it as an output signal.

Although the details of the processing of the decoding processing unit have been described above, the decoding processing of the high frequency signal is stopped by combining this with the encoding processing unit of the first to ninth embodiments described above. It is possible to realize an audio signal transmission device capable of performing.

[0129]

As described in detail above, according to the present invention, the processing of the encoder is monitored, and when it is judged that the processing load needs to be reduced, it is important for the voice quality of the band-divided signal. By stopping the low-frequency high-frequency side encoding process, the processing load can be easily reduced, and multi-channel encoding process can be performed.

Further, when the energy value used for the encoding process of the encoder is used when determining whether or not the reduction of the processing load is necessary, it is possible to reduce the processing load without performing a special measurement. is there.

When the channel for reducing the processing load is fixed, the voice quality of the channel can be given priority.

In the decoding process, the deterioration of the voice quality can be reduced by interpolating the signal of the previous frame instead of the decoded signal of the stopped channel, and the decoding process of another channel can be made possible. effective.

[Brief description of drawings]

FIG. 1 is a block diagram showing an audio signal transmission device according to a first embodiment of the present invention.

FIG. 2 is an operation flowchart of the switch control unit according to the first embodiment of the present invention.

FIG. 3 is an operation flowchart of a switch control unit according to the second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing an improvement of a switch controller according to a third embodiment of the present invention.

FIG. 5 is a flowchart showing the operation of the switch control unit according to the third embodiment of the present invention.

FIG. 6 is a block diagram showing an audio signal transmission device according to a fourth embodiment of the present invention.

FIG. 7 is a block diagram showing an audio signal transmission device according to a fifth embodiment of the present invention.

FIG. 8 is a block diagram showing an audio signal transmission device according to a sixth embodiment of the present invention.

FIG. 9 is a flowchart showing the operation of the switch control unit according to the seventh embodiment of the present invention.

FIG. 10 is a block diagram showing an audio signal transmission device according to an eighth embodiment of the present invention.

FIG. 11 is a block diagram showing an audio signal transmission device according to a ninth embodiment of the present invention.

FIG. 12 is a block diagram showing an audio signal transmission device according to Embodiment 10 of the present invention.

FIG. 13 is a block diagram showing an audio signal transmission device according to an eleventh embodiment of the present invention.

[Explanation of symbols]

1 band division unit, 2 band division unit, 3 high frequency encoder A,
4 high band encoder A5, 6 low band encoder A, 7 processing load measuring unit, 8 switch control unit, 9 switch, 10 switch, 11 data multiplexing unit, 12 signal level measuring unit A, 13, 14 high band encoder B, 15, 16 Low frequency encoder B, 17 Signal level measuring section B, 18 Signal level measuring section C, 19 Signal level measuring section D, 20 Energy value measuring section A, 21 Low frequency encoder C, 22 Low frequency code C, 23 High frequency encoder C, 24 High frequency encoder C, 25
Energy value measuring unit B, 28 Switch control unit, 29,
30 Decoding process selection switch, 31, 32 Delay buffer, 33, 34 High band decoder, 35, 36 Low band decoder, 37, 38 Decoded signal selection switch, 39, 40
Band synthesis section.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04J 1/00 G10L 19/02

Claims (9)

(57) [Claims] 1. A band dividing unit provided for each channel for dividing an audio input signal of each channel into two bands, a low band side and a high band side, and a low band side divided by each band dividing unit. Low frequency encoder provided for each channel for performing the signal encoding processing and the calculation of the processing load value, and the encoding processing and the processing load value of the high frequency side signal divided by each of the band division units. A high-band encoder provided for each channel for calculation, a switch provided for each channel used to control the operation or stop of the encoding process of each high-band encoder, and a code for each channel A determination unit that determines the operation or stop of the encoding process performed in the high band encoder of each channel based on the load monitoring of the encoding process, and the determination unit determines that the encoding process of the high band encoder needs to be stopped. High-frequency mark of each channel, if A switch control unit that selects a switch used to control the operation or stop of the encoding process of the encoder and switches to the side that stops the encoding process, and encodes the control state of the switch of each channel as switch control information. and a data multiplexing unit for multiplexing with data, the determination unit, the low-frequency encoder and above for each channel
Add the processing load value calculated by the high frequency encoder and add it to the value.
Therefore, the encoding process performed by the high band encoder of each channel
It is a processing load measurement unit that determines whether the physical operation or stop is performed.
An audio signal transmission device characterized by: 2. The audio input signal of each channel is set to the low frequency side and the high frequency side.
Provided for each channel divided into two bands on the band side
A band division unit and a coding process of the low-frequency side signal divided by each band division unit.
It is provided for each channel to calculate the processing and processing load values.
Low-band encoder and a coding process of the high-frequency side signal divided by each of the above band dividing units.
It is provided for each channel to calculate the processing and processing load values.
A high band encoder was, operation or control to stop the coding processing of each high-frequency encoder
Switch provided for each channel used to
And each channel based on the load monitoring of the coding process of each channel.
Of the encoding process performed in the high frequency encoder
Is necessary to stop the coding process of the high frequency encoder by the judgment unit and the judgment unit.
If it is determined to be necessary, the code of the high frequency encoder of each channel
Switch used to control the activation or termination of the
Control to switch to the side that stops the encoding process by selecting H
And the switch control information for the control status of the switch for each channel.
And a data multiplexing unit that multiplexes with encoded data.
For example, the determination unit is divided by the band dividing section for each channel
Measure the signal level of the low frequency side signal, and
The operation of the encoding process performed by the high band encoder or
Characterized by a signal level measuring unit for judging stop
That audio signal transmission apparatus. 3. The audio input signal of each channel is set to a low frequency side and a high frequency side.
Provided for each channel divided into two bands on the band side
A band division unit and a coding process of the low-frequency side signal divided by each band division unit.
It is provided for each channel to calculate the processing and processing load values.
Low-band encoder and a coding process of the high-frequency side signal divided by each of the above band dividing units.
It is provided for each channel to calculate the processing and processing load values.
A high band encoder was, operation or control to stop the coding processing of each high-frequency encoder
Switch provided for each channel used to
And each channel based on the load monitoring of the coding process of each channel.
Of the encoding process performed in the high frequency encoder
Is necessary to stop the coding process of the high frequency encoder by the judgment unit and the judgment unit.
If it is determined that the principal sign of the high band encoder of each channel
Switch used to control the activation or termination of the
Control to switch to the side that stops the encoding process by selecting H
And the switch control information for the control status of the switch for each channel.
And a data multiplexing unit that multiplexes with encoded data.
For example, the determination unit, reference numeral Kasho by low frequency coder for each channel
The measured energy value is used and
Operation or stop of the encoding process performed by the high frequency encoder
An audio signal transmission device, which is an energy value measuring unit for determining the 4. The audio input signal of each channel is set to a low frequency side and a high frequency side.
Provided for each channel divided into two bands on the band side
A band division unit and a coding process of the low-frequency side signal divided by each band division unit.
It is provided for each channel to calculate the processing and processing load values.
Low-band encoder and a coding process of the high-frequency side signal divided by each of the above band dividing units.
It is provided for each channel to calculate the processing and processing load values.
A high band encoder was, operation or control to stop the coding processing of each high-frequency encoder
Switch provided for each channel used to
And each channel based on the load monitoring of the coding process of each channel.
Of the encoding process performed in the high frequency encoder
Is necessary to stop the coding process of the high frequency encoder by the judgment unit and the judgment unit.
If it is determined to be necessary, the code of the high frequency encoder of each channel
Switch used to control the activation or termination of the
Control to switch to the side that stops the encoding process by selecting H
And the switch control information for the control status of the switch for each channel.
And a data multiplexing unit that multiplexes with encoded data.
The above-mentioned determination unit is a high band encoder and a low band encoder for each channel.
The energy value used for the encoding process by
The value of the encoding process performed by the high frequency encoder
It must be an energy value measuring unit that determines whether to operate or stop.
An audio signal transmission device characterized by: 5. The sound according to any one of claims 1 to 4.
In the voice signal transmission device, the switch control unit is
Information from the decision unit is used to reduce the coding process of the above high frequency encoder.
High band encoder for each channel, if determined necessary
Used to control the operation or stop of the encoding process of
Select a switch at random and sign the selected switch
It is characterized by performing control to switch to the side that stops the chemical processing
And audio signal transmission device. 6. The sound according to any one of claims 1 to 4.
In the voice signal transmission device, the switch control unit is
Information from the decision unit is used to reduce the coding process of the above high frequency encoder.
High band encoder for each channel, if determined necessary
Used to control the operation or stop of the encoding process of
Select the switch for each channel in order and select the selected switch.
Control to switch to the side that stops the encoding process.
An audio signal transmission device characterized by: 7. The sound according to any one of claims 1 to 4.
In the voice signal transmission device, the switch control unit is
Information from the decision unit is used to reduce the coding process of the above high frequency encoder.
High band encoder for each channel, if determined necessary
Used to control the operation or stop of the encoding process of
Switch selected according to external channel select signal
Then switch the channel to the side that stops the encoding process
An audio signal transmission device characterized by performing control to switch to . 8. Received multiplexed coded data for each
Separated into channel coded data and switch control information
Data separating section and the low-frequency coded data of each channel from the above data separating section.
Low-frequency decoding provided for each channel that performs data decoding processing
And the high-frequency coding data for each channel from the data separation unit.
High frequency recovery provided for each channel for decoding data
And the decoding process of the above high-frequency decoder for each channel
Recovery provided for each switch Yaneru used to control the stop
Signal processing selection switch and a supplementary function that interpolates the decoded signal when the above high-frequency decoder is stopped and controlled.
Interpolated signal generation provided for each channel
And the high frequency decoder or the interpolation signal generating means.
Provided for each channel that selects any of the decoded signals
Based on the decoded signal selection switch and the switch control information from the data separation section,
Of the decoding process selection switch and the decoding signal selection switch
A switch control unit for performing switch control, a low-frequency side decoded signal via the low-frequency decoder, and the above-mentioned decoded signal.
Band synthesis with decoded signal on the high frequency side via signal selection switch
A band provided for each channel that performs
And a high frequency band decoding section for decoding the high frequency band decoding section.
Delay buffer that stores the decoded signal of the previous frame
An audio signal transmission device characterized in that 9. The audio signal transmission device according to claim 8.
Then, the interpolation signal generating means generates a mute signal.
In the mute signal generator that outputs the decoded signal on the high frequency side
An audio signal transmission device characterized by being present .