JPH11261497A - Sound encoder and sound decoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit a code of high importance which is linked with sound encoding and decoding and allows delay of transmission but not non- transmission. SOLUTION: When a code of high importance which allows delay of transmission but not non-transmission is inputted, this information is transmitted to a frame synthesizer 3 and, at the same time, an acknowledge signal from opposite device regarding this transmission is monitored and, until the acknowledge signal is received, a reliability communicator 5 for transmitting the information is provided. The frame synthesizer 3 preferentially transmits a sound coding signal from a sound encoder 2 to a transmission line 100 and information from the reliability communicator 5 is transmitted only when there are some rooms in the capacity of the transmission line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speech encoding device and a decoding device used in mobile communications such as a cellular phone and a car phone.

[0002]

2. Description of the Related Art Conventionally, speech coding and decoding devices used in portable telephones, automobile telephones, and the like have operated on independent transmission paths in which codes are transmitted in only one direction. When transmitting a code that needs to be resistant to transmission errors, the encoding device transmits a redundant code for error detection or correction, and the decoding device transmits the code when a transmission error is detected. Corrected or simply ignored the sign.

[0003]

As described above, even if the conventional encoding device and decoding device transmit data with a redundant code attached thereto, there is no transmission error to the decoding device on the other side and the data is reliably transmitted. Could not be confirmed. Therefore, it is difficult for the encoding apparatus to transmit a code of extremely high importance to the decoding apparatus, which allows transmission delay, but does not allow undelivered transmission.

[0004] Conventionally, a technology that can provide reliability although delay occurs on an unreliable communication path has been realized. However, a technology that operates in conjunction with a speech encoding and decoding system has been realized. Had not been realized.

[0005] In view of the above, in conjunction with speech encoding and decoding, speech encoding / decoding is capable of transmitting a code of extremely high importance such that transmission delay is allowed, but non-transmission is not allowed. Realization of a decoding device has been desired.

[0006]

The present invention employs the following structure to solve the above-mentioned problems. <Structure of Claim 1> A speech encoder that encodes a first signal that is a speech signal, and when a second signal that is an arbitrary signal is input, transmits a second signal, and It monitors whether or not a acknowledgment of receipt of the second signal has been received from the communication partner. If the acknowledgment has not been received, a reliable communicator for transmitting the second signal until receiving the acknowledgment, The first signal output from the encoder is transmitted to the transmission path with priority, and the second signal output from the reliable communication device is transmitted to the transmission path when there is free space in the transmission path. A speech encoding device comprising a frame synthesizer.

<Explanation of Claim 1> In the invention of claim 1,
The first signal is transmitted to the transmission line as it is, but the second signal is transmitted only when there is free space in the transmission line. In the case of the second signal, the signal is not simply transmitted to the transmission path, but is transmitted from the communication partner to the second signal.
It is monitored whether there is a reception confirmation notice that the signal has been received. If no acknowledgment has been received for the transmission of the second signal, the second signal is transmitted to the transmission line until the acknowledgment is received.

[0008] By such an operation, the speech coding apparatus can surely transmit a code of high importance such that non-transmission is not allowed to the partner apparatus. Also, since the voice coded signal is transmitted to the transmission path with priority, and the second signal is transmitted only when there is a vacancy in the transmission path, non-transmission is allowed but immediate like a voice coded signal. It does not have any adverse effect on the transmission of signals that require high quality.

<Structure of claim 2> In the speech coding apparatus of claim 1, the speech coder is of a variable coding rate type, and the maximum value of the coding rate is set to be equal to or less than the transmission rate of the transmission path. This is a speech encoding device characterized by being performed.

<Explanation of Claim 2> The invention of claim 2 relates to the relationship between the transmission rate of the transmission path and the speech coding rate, wherein the coding rate is variable with respect to the transmission rate of the transmission path, and The maximum value of the conversion rate is set to be equal to or less than the transmission rate of the transmission path. As a result, it is easy to secure free space in the transmission path, and as a result, the second signal can be transmitted stably.

<Structure of Claim 3> A first signal, which is an audio signal, is encoded at an encoding rate equal to the transmission rate of the first transmission path having a fixed transmission rate, and the code is transmitted to the first transmission path. And a second signal that is an arbitrary signal is transmitted to a second transmission path whose transmission rate is not fixed, and a reception confirmation notification from the communication partner for the transmission of the second signal is transmitted. And a reliability communicator that sends a second signal until receiving a reception confirmation notification if the reception acknowledgment notification is not received.

<Explanation of Claim 3> The invention of claim 3 uses a first transmission line having a transmission rate equal to the speech coding rate and a second transmission line having an unfixed transmission rate. , And a first signal and a second signal. Here, the first transmission line and the second transmission line may be physically different lines. For example, a transmission line having a non-constant transmission rate, such as the Internet, may be used as the second transmission line. Can be.

As a result, even if a sufficient transmission rate cannot be ensured in the second transmission path or a transmission error occurs, the second signal is reliably transmitted to the other party even if there is a certain delay. And the second signal has no adverse effect on the transmission of the first signal.

According to a fourth aspect of the present invention, there is provided an audio encoder for encoding the first signal, which is an audio signal, at an encoding rate equal to or lower than a minimum transmission rate of a transmission path whose minimum transmission rate is guaranteed, When the second signal is input, the second signal is transmitted, and at the same time, it is monitored whether or not a reception acknowledgment notice for the transmission of the second signal is received from a communication partner. If the notification is not received, the reliable communication device that transmits the second signal until the notification is received, and the first signal output from the speech encoder is transmitted with priority to the transmission path, and the reliable communication device transmits the first signal. The second signal to be output is a speech encoding apparatus characterized by comprising a frame synthesizer for sending out to the transmission line when the transmission line has free space.

<Explanation of claim 4> According to the invention of claim 4, the minimum transmission rate of the transmission path is guaranteed, and the coding rate of the speech encoder is equal to or less than the minimum transmission rate of the transmission path. Things. Since the first signal is preferentially output to such a transmission path, the second signal is not transmitted when there is no margin for the transmission rate in the transmission path. And the second signal can be reliably transmitted to the other party.

<Structure of Claim 5> Of the capacity of the transmission line,
A transmission path monitor for notifying a value of a transmission rate that can be used by the own apparatus, an audio encoder for encoding a first signal as an audio signal at a fixed encoding rate, and a second signal as an arbitrary signal Is input, a second signal is transmitted, and it is monitored whether or not a reception acknowledgment notification has been received from a communication partner for the transmission of the second signal. If no reception acknowledgment notification has been received, A reliable communication device for transmitting a second signal until it is received, and a first signal output from the speech coder is preferentially transmitted to the transmission path, and a second signal output from the reliability communication device is A speech encoding apparatus comprising: a frame synthesizer that sends a transmission rate to a transmission path when there is a vacancy in a transmission rate value notified from the transmission path monitoring apparatus.

<Explanation of Claim 5> According to the invention of claim 5, the transmission rate of the transmission line is not guaranteed, and the first transmission line using the transmission line whose value of the transmission rate that can be used by its own device is not constant is used. And the second signal are transmitted. Here, it is assumed that the transmission rate that can be used by the own apparatus includes a case where the transmission rate is equal to or lower than the coding rate of the audio encoder.

Even when such a transmission path is used, the first
Is transmitted with priority, and the second signal is transmitted only when the value of the transmission rate usable by the own device is equal to or higher than the coding rate of the first signal. The transmission of the first signal has no adverse effect, and the second signal can always be transmitted to the other party even though there is some delay.

<Structure of Claim 6> In the speech coding apparatus according to any one of claims 1 to 5, when receiving a reception confirmation notice from a communication partner, the speech encoding apparatus transmits the notice to the speech encoder. And a voice coder that changes its operation by receiving a notification from the reliability communicator that the acknowledgment notification has been received. .

<Explanation of Claim 6> According to the invention of claim 6, when a reception confirmation notification is received from a communication partner, the operation of the speech encoder is changed in response to the notification. Here, the operation of the speech encoder to be changed is, for example, an operation of updating a code in a common codebook for encoding and decoding held by both the encoder and the decoder. Any operation can be applied as long as the operation is performed using a reception confirmation notification as a trigger. According to a sixth aspect of the present invention, the operation of the speech encoder can be changed at a certain timing by such an operation.

<Structure of Claim 7> Claims 1, 2, 4,
In the speech encoding device according to any one of the fifth and sixth aspects, when the second signal is received, a reliable communication device that sends a reception confirmation notification and a reception confirmation notification from the reliability communication device are sent to the first communication device.
And a frame synthesizer for transmitting the same signal to the same transmission path.

<Explanation of Claim 7> According to the invention of claim 7, the first signal from the speech coder and the acknowledgment notification from the reliable communicator are transmitted from the frame synthesizer to the same transmission path. It is something to do. Thereby, there is an effect that a single transmission path can be shared by the first signal and the reception confirmation notification.

<Structure of Claim 8> An audio decoder for decoding an audio signal as a first signal from an encoded signal received via a transmission path, and a second signal which is an arbitrary signal from a communication partner. Speech decoding characterized by comprising a reliable communication device for transmitting a reception confirmation notification when a signal is received, and a frame synthesizer for transmitting a reception confirmation notification transmitted from the reliable communication device to a transmission path. Device.

<Explanation of Claim 8> The invention of claim 8 is a speech decoding apparatus having a function corresponding to the function of the speech encoding apparatus in the inventions of claims 1 to 7. When the reliability communicator receives the second signal from the other party, it sends out a reception confirmation notice. Therefore, the other party uses the reception confirmation notice to know that the second signal has reached the decoding device without fail. Can be.

<Structure of claim 9> In the speech decoding apparatus according to claim 8, the frame distributor receives the coded signal and the acknowledgment notice via the same transmission path, and the frame distributor receives the coded signal and the acknowledgment notification. An audio decoding apparatus comprising: an audio decoder that decodes an audio signal from an encoded signal; and a reliable communication device that receives a reception confirmation notification received by a frame distributor.

<Explanation of Claim 9> In the invention of claim 9, the frame distributor receives the coded signal and the acknowledgment notice from the same transmission line. Thereby, there is an effect that the transmission of the first signal output by the communication partner and the transmission of the reception confirmation notification returned by the communication partner can be shared by the same transmission path.

[0027]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Embodiment 1 <Configuration> FIG. 1 is a block diagram showing Embodiment 1 of a speech encoding / decoding apparatus according to the present invention. The illustrated device comprises a speech input device 1, a speech coder 2, a frame synthesizer 3, a frame distributor 4,
It comprises a reliability communicator 5, an audio decoder 6, an audio output device 7, and signal lines 8 to 15.

The voice input device 1 has a function of taking in input voice and converting it into a digital code. The voice encoder 2 has a function of performing variable coding rate type voice coding. The maximum value of the encoding rate of the audio encoder 2 is designed to be equal to or less than the transmission rate of the transmission path 101.

The frame synthesizer 3 is a functional unit for synthesizing a voice code frame. The voice synthesizer 3 synthesizes a voice coded signal (first signal) from the voice coder 2 and a signal line 1 via a signal line 8.
1 and a function of inputting the second signal from the reliable communicator 5 and synthesizing these signals to output to the transmission path 101.

The frame distributor 4 has a function of distributing a speech code frame from a signal received from the receiving path 102. The reliable communicator 5 is provided to secure a reliable virtual communication path, transmits a second signal, which is an arbitrary signal, and confirms the transmission of the second signal from a partner device. (ACK: acknowledgment signal), and has a function of transmitting the second signal until the acknowledgment signal is not received. The audio decoder 6 has a function of operating in pairs with the audio input device 1 provided in the partner device. The audio output device 7 has a function of converting a digital code into an analog audio signal and outputting the signal. In this case, the transmission path 101 is actually used.
The configuration of a modem and a radio circuit connected to the receiving path 102 and the like is omitted in the figure.

A signal line 8 transmits a speech coded signal from the speech coder 2 to the frame synthesizer 3, and a signal line 9.
Is a signal line for sending to the reliable communicator 5 when it is desired to transmit highly important information from the voice encoder 2 to the partner device, which allows transmission delay but does not permit non-transmission. The signal line 11 is a signal line for transmitting such highly important information and a confirmation signal (hereinafter, referred to as an acknowledgment signal) to the partner device from the reliable communication device 5 to the frame synthesizer 3.

The signal line 12 is a signal line for transmitting the coded speech signal distributed by the frame distributor 4 from the receiving path 102 to the speech decoder 6, and the signal line 15 is distributed by the frame distributor 4. Signal lines and signal lines 14 for transmitting highly important information and an acknowledgment signal from the partner device to the reliable communication device 5 that transmission delay is allowed, but not transmitted are not allowed. This is a signal line for transmitting highly-relevant information to the audio decoder 6.

Further, the signal line 10 is a signal line for transmitting the information to the speech encoder 2 when the reliability communication device 5 receives an acknowledgment signal from the partner device, and the signal line 13 is
A signal for transmitting the information to the reliable communication device 5 when it is desired to transmit information of a high importance from the voice decoder 6 to the partner device such that transmission delay is permitted but not transmitted. Line.

The frame synthesizer 3, the reliable communication device 5,
The signal line 11 is used for transmitting a speech coded signal and information of high importance that transmission delay is allowed, but untransmitted and unacceptable, and an acknowledgment signal for information received from the other device. Shared to send out. In addition, the frame distributor 4, the reliable communication device 5, and the signal line 15 receive a speech coded signal from the partner device and information of high importance that transmission delay is permitted but not transmitted. In addition to the above case, it is shared to receive an acknowledgment signal from the partner device.

<Operation> The speech coder 2 uses the signal line 8 to change the frame of the code having relatively low importance such that the immediacy of transmission is required or the non-transmission is allowed to some extent. It is sent to the synthesizer 3. As such a code, for example, information equivalent to that output by a conventional speech encoder, that is, in various codebooks owned by the speech encoder, the characteristics of the input speech are most accurately expressed. There is information on an index for a given code. Also, since the speech encoder 2 is of a variable encoding rate type, the transmission rate sent to the frame synthesizer 3 is variable.

The frame synthesizer 3 receives a code frame from the reliable communication device 5 via the signal line 8 and the signal line 11 and sends the code frame to the transmission path 101. However, since the capacity of the transmission line 101 is limited, the code frame from the signal line 8 is preferentially transmitted, and if the code frame does not fit in the capacity of the transmission line 101, a part of the code frame from the signal line 11 or Discard everything.

The frame distributor 4 separates the code frame received from the receiving path 102, and sends the code frame and the acknowledgment signal received from the reliable communication device of the partner device to the reliable communication device 5 using the signal line 15. The other code frames are sent to the speech decoder 6 using the signal line 12.

The speech decoder 6 decodes the code frame received from the frame distributor 4 or the reliable communication device 5, and reconstructs a speech signal.

Next, a description will be given of a case where the speech encoder 2 wants to transmit information of high importance to the partner apparatus such that transmission delay is permitted but not transmitted.
Such information includes, for example, a codebook such as a noise code vector, a gain code, a pitch lag code, and a pitch gain code, as shown in Japanese Patent Application No. 9-318598 filed by the inventors. Is assumed to be update data.

That is, in a speech encoding / decoding device, generally, both an encoder and a decoder hold a common codebook for encoding and decoding. Here, the quality of voice is improved by updating a code that is rarely used in the codebook with a code newly generated by the encoder in accordance with the nature of the voice input to the encoder. Can be. However, it is important that the contents of the codebooks of the encoder and the decoder match, and if the codebooks of the encoder and the decoder have inconsistent codes, the index (index ) On the encoder side, the decoder will pick out a code that is different from what the encoder expects. This is a factor that greatly degrades sound quality. For this reason, when updating the code in the codebook, the encoder must surely transmit the update data to the decoder. Also, the encoder must notify the other party that the update data has been reliably transmitted to the decoder. This is important so that the encoder does not erroneously reference an index having an inconsistent code between the encoder and the decoder until the update data is transmitted to the decoder.

FIG. 2 is an explanatory diagram showing a sequence in a case where highly important information is transmitted to the partner device.

When the speech encoder 2 wants to transmit information INFO1 of high importance that transmission delay is permitted, but not transmission of the information to the partner device, the information INFO1 is transmitted through the signal line 9 to the signal line 9 in a reliable manner. It is sent to the communication device 5. At this time, an identification number (1 in this case) is given.

The reliability communicator 5 packetizes INFO1 and passes it to the frame synthesizer 3 as PACKET1.

The frame synthesizer 3 has a low transmission rate that the speech encoder 2 sends out using the signal line 8 and the transmission path 10
If there is room in 1, PACKET1 is superimposed and transmitted.

The reliability communicator 5 waits for the acknowledgment signal ACK for a certain period of time. However, if the time-out occurs as shown in the figure, the PACKET 1 passes the PACKET 1 again to the frame synthesizer 3 (this is due to a transmission error or transmission path). This means that PACKET 1 has not reached the partner device within a predetermined time because of a lack of capacity of 100, etc.).

Upon receiving the acknowledgment signal ACK1 from the partner device, the frame distributor 4 transmits this signal to the signal line 1
5 to the reliable communicator 5.

The reliability communicator 5 sends a signal SE notifying the speech encoder 2 that the INFO 1 has been transmitted correctly.
NT1 is passed through the signal line 10.

Next, it is assumed that the speech encoder 2 sends information INFO2 of high importance such that transmission delay is allowed but not yet allowed to be transmitted, and furthermore, INFO3 to the partner device. In this case, the identification numbers are two and three.

The reliability communicator 5 sends out PACKET3 following PACKET2. However, the illustrated example shows a case where ACK3 is received prior to acknowledgment signal ACK2. In this case, the reliable communication device 5
At the same time as notifying the speech encoder 2 that the FO3 has been transmitted correctly, the PACKET2 is transmitted again (this is because
This means that the acknowledgment signal ACK2 from the partner device has not reached its own device due to a transmission error, insufficient capacity of the transmission path 100, or the like.)

Even if the speech encoder 2 sends out INFO2 before INFO3, SENT3 is sent to SEN.
This indicates that there is a possibility of reception before T2.

Next, a case where a PACKET is received from a partner device will be described. FIG. 3 is an explanatory diagram in this case. Here, the operation between the own apparatus and the other apparatus is shown in FIG.
3 and FIG. 3, in actual communication, transmission of INFO from the speech encoder 2 and transmission of I / O to the speech decoder 6
NFO reception is performed completely in parallel using a common frame combiner 3, a common frame distributor 4, and a common reliability communicator 5.

First, when the frame distributor 4 finds the PACKET 4 in the frame received from the partner device,
It is separated and passed to the reliable communication device 5.

The reliability communication device 5 receives IN from PACKET4.
The FO 4 is taken out and passed to the audio decoder 6 via the signal line 14, and at the same time, the acknowledgment signal ACK 4 is sent out to the frame synthesizer 3 via the signal line 11. And P
Similar processing is performed for ACKET5.

<Effects> As described above, according to the first embodiment,
The following effects are obtained. a) The voice encoder 2 can reliably transmit a code of high importance such that non-transmission is not allowed to the voice decoder 6 of the partner device.

B) After the important code is transmitted to the speech decoder 6 of the partner device, the speech coder 2
, A notification to that effect can be received. Therefore, assuming that such a code is update data for updating a code in the above-mentioned codebook, the audio encoder 2 can surely know that it has been transmitted to the other party. By starting the reference of the sign using as a trigger,
It is possible to prevent the encoder and the decoder from referring to an index having an inconsistent code.

C) Since the frame synthesizer 3 preferentially transmits the code frame from the signal line 8, the code frame from the signal line 11 is not permitted to be transmitted, but is a code frame that requires immediacy. Has no adverse effect on transmission.

D) The single transmission path 101 can be shared for transmitting the code output from the speech encoder and transmitting the acknowledgment signal to the partner device. At the same time, the single receiving path 102 can be shared for receiving the code output by the speech encoder of the partner device and for receiving the acknowledge signal returned by the partner device.

<< Example 2 >> Example 2 is a case where the present invention is applied to a speech encoder / decoder having a fixed encoding rate and two types of transmission paths having different characteristics.

<Structure> FIG. 4 is a diagram showing the structure of the second embodiment. The illustrated device includes a speech input unit 1, a speech encoder 2, a reliability communicator 5, a speech decoder 6, a speech output unit 7, and signal lines 8 to 8.
It consists of fifteen. Here, the points different from the first embodiment are that the speech encoder 2 and the speech decoder 6 have a fixed coding rate, and that the frame synthesizer 3 and the frame distributor 4 in the first embodiment are unnecessary. That is, two types of transmission paths having different properties are provided.

These transmission lines 200 are: 200A: always having a constant transmission rate (equal to the coding rate of the voice encoder 2) 200B: the transmission rate is not constant and may not be used at all Things.

Here, the transmission line 200B is connected to the transmission line 200A.
Only low reliability may be provided as compared with. That is, the transmission path 200B does not need to have functions such as error detection and error correction in the transmission path 201B and the reception path 202B.

The transmission line 200B can be used even if it has a larger delay than the transmission line A. For example, even if a geosynchronous artificial satellite line having a large transmission delay is used, the delay of the voice coded signal itself is reduced. Does not participate.

<Operation> Only differences from the first embodiment will be described. The fixed-rate speech coder 2 uses a signal line 8 for a code of relatively low importance such that immediate transmission is required or non-transmission is allowed to some extent.
Is transmitted to the transmission path 201A as it is.

The speech decoder 6 decodes the code frame received from the receiving path 202A or the reliable communication device 5, and reconstructs a speech signal.

Next, a description will be given of a case where the speech encoder 2 wants to transmit a code of high importance to a partner apparatus, which allows transmission delay but does not permit non-transmission.
The code having such a high importance in the specific example 2 is, for example, codebook update data such as a noise code vector described in the specific example 1.

When transmitting such a code, the speech encoder 2 sends a code frame to the reliable communication device 5 using the signal line 9.

The reliability communicator 5 includes a signal line 11 and a signal line 1
5, the transmission path 201B and the reception path 202
It communicates with the partner device via B. Although the immediacy of code transmission is not guaranteed, a transmission error caused by the transmission path 200B between the devices is made transparent using a retransmission procedure, and a reliable virtual communication path free from transmission errors is secured. The reliability communicator 5 monitors all the identifiers of the transmitted code frames, and repeatedly transmits the code frames until receiving an acknowledgment signal via the signal line 15 from the reliability communicator of the partner device.

When the code frame is correctly received from the reliable communication device of the partner device, the code frame is transmitted to the speech decoder 6 through the signal line 14 and at the same time, the reliable communication device of the partner device is transmitted through the signal line 11. To return an acknowledgment signal.

<Effects> As described above, according to the specific example 2,
The following effects can be obtained. a) The voice encoder 2 can reliably transmit a code of high importance such that non-transmission is not allowed to the voice decoder 6 of the partner device.

B) After the important code is transmitted to the speech decoder 6 of the partner device, the speech coder 2
, A notification to that effect can be received.

C) Even if a sufficient transmission rate cannot be secured on the transmission line 200B or a transmission error occurs, non-transmission is allowed, but transmission of a code frame requiring immediacy is not adversely affected at all. Absent.

D) The quality of the coded speech can be improved by transmitting the codebook update data by effectively using the transmission path with low reliability or large transmission delay.

<< Embodiment 3 >> Embodiment 3 is a case where the present invention is applied to a voice encoder / decoder having a fixed coding rate and a variable rate transmission path which guarantees a minimum transmission rate.

<Structure> FIG. 5 is a view showing the structure of the third embodiment. The device shown comprises an audio input device 1, an audio encoder 2, a frame synthesizer 3, a frame distributor 4, a reliability communicator 5, an audio decoder 6, an audio output device 7, and signal lines 8 to 15,
Although the block configuration on the drawing is the same as that of the first embodiment, the following points are different from the first embodiment.

That is, the difference from the first embodiment is that the speech encoder 2 and the speech decoder 6 have a fixed encoding rate and the transmission rate of the transmission path 300 (the transmission path 301 and the reception path 302) is variable. It is to be. However, the transmission path 300
Is higher than the encoding rate of the audio encoder 2.

<Operation> Only differences from the first embodiment will be described. It is assumed that the first signal from the voice encoder 2 and the second signal from the reliability communicator 5 are the same as in the second embodiment.

The fixed-rate speech coder 2 uses the signal line 8 for codes of relatively low importance that require immediate transmission or allow non-transmission to some extent. It is sent to the frame synthesizer 3 as it is.

The frame synthesizer 3 includes a signal line 8 and a signal line 1
1 and sends it to its own transmission path 301. Here, the code frame from the signal line 8 is always output to the transmission path 301, but the code frame from the signal line 11 is only output when the transmission rate of the transmission path 301 has room for transmitting the code frame. Send out. Otherwise, part or all of the code frame from the signal line 11 is discarded.

<Effects> As described above, according to the third embodiment,
The following effects can be obtained. a) By using the variable transmission rate type transmission path 300, the voice encoder 2 can reliably transmit a code of high importance such that non-transmission is not allowed to the voice decoder 6 of the partner apparatus.

B) After the important code is transmitted to the speech decoder 6 of the partner device, the speech coder 2
, A notification to that effect can be received.

C) Since the frame synthesizer 3 preferentially transmits the code frame from the signal line 8, the code frame from the signal line 11 is not transmitted when there is no margin in the transmission rate of the transmission line 300. Therefore, such a signal line 11
Are allowed to be untransmitted, but have no adverse effect on the transmission of code frames requiring immediacy.

D) The quality of the coded speech can be improved by transmitting the codebook update data by effectively utilizing the margin of the traffic on the transmission line.

<< Example 4 >> Example 4 shows a case where communication is performed by a voice encoder / decoder with a fixed coding rate using a transmission line of a multiplex transmission apparatus shared with other communications. I have.

<Structure> FIG. 6 is a diagram showing the structure of the embodiment 4. The apparatus shown in the figure includes an audio input unit 1, an audio encoder 2, a frame synthesizer 3, a frame distributor 4, a reliable communication unit 5, an audio decoder 6, an audio output unit 7, and signal lines 8 to 15, ,
A transmission path monitor 16 is provided.

This embodiment is different from the third embodiment in that the transmission path 400 is applied to a multiplex transmission apparatus shared with another user or a completely different type of communication (data communication, image communication, etc.). It is. For example, such a transmission path 4
As 00, the Internet or the like can be used.

It is desirable that the transmission path 400 of such a multiplex transmission apparatus has a function of guaranteeing a minimum transmission rate for a specific user or a specific type of communication. is there. Even in such a case, in this specific example, based on the information of the available transmission rate from the transmission path monitor 16, information of high importance such that non-transmission is not allowed is reliably transmitted. .

The transmission line monitor 16 constantly monitors the traffic of the multiplex transmission device, and has a function of transmitting the transmission rate usable by this device to the frame synthesizer 3. The other components are the same as those of the third embodiment, and the description is omitted here.

<Operation> Only differences from the third embodiment will be described. The fixed-rate speech coder 2 uses the signal line 8 to directly synthesize a frame for a code of relatively low importance, which requires immediate transmission or allows non-transmission to some extent. To the container 3.

The frame synthesizer 3 includes a signal line 8 and a signal line 1
1 and sends it to its own transmission path 401. Here, the code frame from the signal line 8 is always output to the transmission path 401, but the code frame from the signal line 11 is transmitted based on the information on the available transmission rate given from the transmission path monitor 16. Is transmitted only when there is room to transmit the code frame at the transmission rate of. Otherwise, part or all of the code frame from the signal line 11 is discarded.

<Effects> As described above, according to the fourth embodiment,
The following effects can be obtained. a) Using the transmission path 400 whose transmission rate is not guaranteed,
The voice encoder 2 can reliably transmit a code of high importance such that non-transmission is not allowed to the voice decoder 6 of the partner device.

B) After the important code is transmitted to the speech decoder 6 of the partner device, the speech coder 2
, A notification to that effect can be received.

C) Since the frame synthesizer 3 preferentially transmits the code frame from the signal line 8, the code frame from the signal line 11 is not permitted to be transmitted, but is a code frame that requires immediacy. Has no adverse effect on transmission.
In other words, based on the information on the available transmission rate notified from the transmission path monitor 16, the frame synthesizer 3 has high importance information such that non-transmission is not allowed only when there is a margin in the transmission rate. , The speech encoder 2
There is no adverse effect on the transmission of the audio signal.

D) By sharing the multiplex transmission device with a plurality of users or completely different types of communication (data communication, image communication, etc.), a margin of traffic not used by other users or different types of communication is provided. The user can effectively use the minutes. Thereby, the quality of the coded voice can be improved by transmitting the codebook update data to the traffic margin.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a specific example 1 of a speech encoding / decoding device of the present invention.

FIG. 2 is an explanatory diagram showing a sequence in a case where highly important information is transmitted to a partner device in the specific example 1 of the speech encoding / decoding device of the present invention.

FIG. 3 is an explanatory diagram showing a sequence in a case where highly important information is received from a partner device in the specific example 1 of the speech encoding / decoding device of the present invention.

FIG. 4 is a configuration diagram of a specific example 2 of the speech encoding / decoding device of the present invention.

FIG. 5 is a configuration diagram of Example 3 of the speech encoding / decoding device of the present invention.

FIG. 6 is a configuration diagram of Example 4 of the speech encoding / decoding device of the present invention.

[Explanation of symbols]

 2 audio encoder 3 frame synthesizer 4 frame distributor 5 reliable communicator 6 audio decoder 100, 200A, 200B, 300, 400 transmission path

Claims (9)

[Claims] 1. An audio encoder that encodes a first signal that is an audio signal, and when a second signal that is an arbitrary signal is input, the second signal is transmitted and the second signal is transmitted. A reliability communicator that monitors whether a acknowledgment notice from the communication partner for the transmission of the second signal has been received, and, if the acknowledgment notice has not been received, sends the second signal until it is received; The first signal output from the speech encoder is transmitted preferentially to the transmission path, and the second signal output from the reliable communication device is transmitted.
And a frame synthesizer for transmitting the signal to the transmission path when there is a free space in the transmission path. 2. The audio encoding apparatus according to claim 1, wherein the audio encoder is of a variable encoding rate type, and a maximum value of the encoding rate is set to be equal to or less than a transmission rate of the transmission path. Characteristic speech coding device. 3. A voice code for coding a first signal, which is a voice signal, at a coding rate equal to a transmission rate of a first transmission path having a fixed transmission rate, and transmitting the code to the first transmission path. And transmitting a second signal, which is an arbitrary signal, to a second transmission line whose transmission rate is not fixed, and whether a reception confirmation notification has been received from a communication partner for the transmission of the second signal. And a reliability communicator that sends out the second signal until it receives the acknowledgment notification if it does not receive the acknowledgment notification. 4. An audio encoder for encoding a first signal, which is an audio signal, at an encoding rate equal to or lower than the minimum transmission rate of a transmission path whose minimum transmission rate is guaranteed, and an arbitrary signal. When the second signal is input, the second signal is transmitted, and at the same time, it is monitored whether or not a reception acknowledgment for the transmission of the second signal is received from a communication partner. If not received, a reliable communication device that sends the second signal until it is received, and a first signal output from the speech encoder is sent with priority to the transmission line, and the reliable communication And a frame synthesizer for transmitting the second signal output from the transmission line to the transmission line when there is a free space in the transmission line. 5. A transmission path monitor for notifying a value of a transmission rate that can be used by its own device among a capacity of a transmission path, and a voice coding for coding a first signal which is a voice signal at a fixed coding rate. When a second signal, which is an arbitrary signal, is input, the second signal is transmitted, and it is determined whether or not a reception acknowledgment notice from a communication partner for the transmission of the second signal has been received. Monitoring, if the reception acknowledgment notification is not received, the reliability communicator that sends the second signal until it is received, and the first signal output from the audio encoder is given priority over the transmission path. A second signal output from the reliable communication device, and a frame synthesizer for transmitting the second signal to the transmission line when there is a vacancy in the value of the transmission rate notified from the transmission line monitor. A speech coding apparatus characterized by the above-mentioned. 6. A voice coder according to claim 1, wherein, when receiving a reception confirmation notification from a communication partner, a reliable communicator that transmits the notification to the voice coder. A speech coder for changing the operation thereof by receiving a notification from the reliability communicator that the acknowledgment has been received. 7. The speech encoding apparatus according to claim 1, wherein, when the second signal is received, a reliability communicator that transmits a reception confirmation notice; A speech coding apparatus, comprising: a frame synthesizer for transmitting a reception confirmation notification from the reliable communication device to the same transmission path as a first signal. 8. An audio decoder for decoding an audio signal as a first signal from an encoded signal received via a transmission path, and a second signal which is an arbitrary signal received from a communication partner. Is a voice communication device comprising: a reliable communication device for transmitting a reception confirmation notification; and a frame synthesizer for transmitting the reception confirmation notification transmitted from the reliability communication device to the transmission path. 9. The speech decoding apparatus according to claim 8, wherein: a frame distributor that receives the coded signal and the reception confirmation notice via the same transmission path; and a coded signal received by the frame distributor. An audio decoding device comprising: an audio decoder for decoding an audio signal; and a reliable communication device for receiving a reception confirmation notification received by the frame distributor.