JP3607586B2 - Audio delay control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voice delay controlling system capable of eliminating the phenomenon of repeated outputs of the same sound. SOLUTION: When the value of a delay control signal (f) is changed to a (f)' (f<f'), a level comparison detecting part 6 compares the signal levels of memories 4 and 5 with a prescribed signal level (n), and a detecting part 6 decides that it is a silent state when the former is smaller than the latter, and then outputs a control signal (g) to a control part 3. The control part 3 outputs data at the timing of a read signal (e) without counting up a read address (q) when the silent part is detected. This state is repeated by a specified number of times.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an audio delay control apparatus, and more particularly, to an audio delay control method for delaying an audio signal in response to a video image delay in a broadcasting station.
[0002]
[Prior art]
Conventionally, in a broadcast station, when a video signal is received using a public telephone line, a satellite line, a microwave line, etc., and the video signal is used as a broadcast material, the video signal is synchronized with the in-house synchronization signal. In order to synchronize with the video system, a frame synchronizer or the like is used to perform synchronous absorption of the video system.
[0003]
Therefore, since a delay always occurs in the video signal, the audio signal is output faster than the video signal (screen), and the audio signal also generates a time delay corresponding to the delay of the video signal. There is a need.
[0004]
In the audio delay control apparatus that controls the delay with respect to the audio signal, the audio delay time is set while comparing the video signal (screen) and the audio signal when setting the audio delay time.
[0005]
In other words, in the conventional delay control method, as shown in FIG. 8, the signal A ′ transmitted from the source signal A with a delay setting time of ta is less than tb from the signal of the source signal A. When the setting is changed to the delay setting time, the signal level of the delayed signal A ′ is decreased with time (fade out).
[0006]
On the other hand, the signal level of the signal A ″ delayed by the delay set time of tb is increased with time (fade in). The set time is changed by adding the two processed signals. If you are processing.
[0007]
[Problems to be solved by the invention]
In the conventional delay control system described above, it is possible to perform processing without any particular problem in terms of audibility when changing a short delay time (about 10 ms). However, when the set time of the delay time is greatly changed, if the audio delay time is set longer than the current delay time, the same audio is output again as shown in FIG. This phenomenon becomes more prominent as the difference in setting change time increases.
[0008]
Further, when the set time is shorter than the current delay set time, the audio portion is deleted as shown in FIG. This phenomenon also appears more prominently as the difference in setting change time is larger.
[0009]
Japanese Patent Laid-Open No. 6-28781 discloses a method for changing the length of audio data in which the length of a silent section in audio data is adjusted to change the total length of the audio data to a desired value.
[0010]
In this audio data length changing method, as shown in FIG. 11, the operation of the input unit 11 designates audio data to be changed in length and inputs a desired value for the entire length. The designated audio data is read from the recording medium 13 by the running of the application program 12 to recognize the total length (process 12a of the application program 12), and the position and length of the silent section are individually detected (process). 12b) Further, the length of the silent section is adjusted according to a predetermined rule by the difference between the recognized value and the desired value (processes 12c and 12d), and the adjusted new audio data is stored in the recording medium 13. (Process 12e).
[0011]
In the above-described audio data length changing method, when changing the length of the audio data recorded on the recording medium 13, a silent portion in the audio data recorded on the recording medium 13 is detected in advance and set as desired. In order to make it longer, the length of the silent part is changed and recorded again.
[0012]
In the technique described in this publication, it is necessary to individually detect the position and length of the silent time in advance in order to change the time of the audio data. As for the operation of increasing / decreasing the silent time, the silent portion data is deleted when the silent time is shortened, and the silent data is added to lengthen the silent time. Therefore, since the technology described in this publication merely deletes and adds silence data, the above problem cannot be solved.
[0013]
Accordingly, an object of the present invention is to provide an audio delay control apparatus that can solve the above-described problems and eliminate the phenomenon of repeated output of the same sound.
[0014]
Another object of the present invention is to provide an audio delay control device capable of eliminating the problem of missing sound.
[0015]
[Means for Solving the Problems]
An audio delay control device according to the present invention is an audio delay control device that performs delay control in a delay memory that delays an input audio signal , and a first memory that temporarily holds output data from the delay memory; A second memory that temporarily holds output data from the first memory; a data that is held in the first memory in response to a change in a set time of the delay time of the audio signal; and the second memory Detection means for detecting the silent portion of the audio signal by comparing with the held data, and control means for controlling to change the length of the silent portion detected by the detection means.
[0016]
In another audio delay control apparatus according to the present invention, in the above configuration, the control means adds a silence signal to a silence portion of the audio signal when the set time is longer than a current delay time. ing.
[0017]
Another sound delay control apparatus according to the present invention, in the above configuration, the control means, to perform the deletion of the silent signal from silence the audio signal when a shorter setting time than the delay time of the current I have to.
[0018]
That is, the audio delay control method of the present invention is characterized in that delay control can be performed without causing a sense of incongruity when the delay time setting is changed.
[0019]
Normally, if the delay time for the sound is longer than the current delay time, the same sound is repeatedly output, and if the delay time is shorter than the current delay time, a phenomenon that the sound corresponding to the shortened time is deleted (not reproduced) occurs. .
[0020]
In the audio delay control system of the present invention, the silent part of the voice is detected with respect to the change of the set time of the delay time, and the length of the silent part is changed to cope with the change of the delay time, as described above. The control accompanying the change of the voice time is realized without causing the phenomenon.
[0021]
More specifically, in the audio delay control system of the present invention, as a technique for avoiding the same audio being repeatedly output, when the set time is set longer than the current delay time, the silent portion of the audio (with less level fluctuation) : A region with a small amplitude) is detected, and a silence signal is added to the silence part, that is, the speech data is not called out from the memory, and the prefix data is used as it is, so that the voice delay time is increased. It is further delayed.
[0022]
In that case, instead of suddenly adding the silent part to the setting change time, the difference in the setting time (the difference between the current setting time and the time after resetting) is divided equally and added in several times. Yes.
[0023]
Further, in the audio delay control method of the present invention, when the set time is shorter than the current delay set time, the silent portion is detected in the same manner as the above-described process, and the difference between the set times (the current set time and The time difference from after resetting) is divided evenly and divided into several times to delete the silent part, that is, by counting up the address for reading the voice data from the memory, the voice part is deleted. It is preventing.
[0024]
By performing the control as described above, compared to the conventional delay control method, the phenomenon of repeated output of the same sound that occurs when the delay time is lengthened, or the lack of sound that occurs when the delay time is shortened Can be eliminated.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an audio delay control apparatus according to an embodiment of the present invention. In FIG. 1, an audio delay control apparatus according to an embodiment of the present invention includes an A / D (analog / digital) converter 1, a delay memory 2, a control unit 3, memories 4, 5, and a level comparison detection unit 6. And an output buffer memory 7 and a D / A (digital / analog) converter 8.
[0026]
The audio input signal a is converted into digital audio data b by the A / D converter 1 at the timing of the sampling frequency FS. The control unit 3 outputs a write address p and a write signal d for writing the A / D conversion data b to the delay memory 2 by the delay control signal f, and delays to generate the delay time of the delay control signal f. A read address q and a read signal e are output to the memory 2.
[0027]
The memory 4 temporarily records the delayed audio data c from the delay memory 2. The memory 5 temporarily records the audio data m that has been temporarily recorded in the memory 4. The level comparison detection unit 6 determines whether or not the level difference between the recorded audio data h in the memory 4 and the recorded audio data i in the memory 5 is smaller than the specified signal level n in synchronization with the timing of the read signal e from the delay memory 2. If it is less than the prescribed signal level n, it is judged as a silent part, and the control signal g is output, and the recorded audio data i in the memory 5 is output to the output buffer memory 7.
[0028]
The D / A converter 8 converts the recorded audio data k in the output buffer memory 7 from digital audio data to an analog audio signal (output signal) 1 at the timing of the sampling frequency FS and outputs it.
[0029]
FIG. 2 is a diagram showing a configuration example of the delay memory 2 of FIG. In FIG. 2, the delay memory 2 has a loop memory (ring buffer) configuration. The time progression in the loop memory indicates the clockwise direction (arrow in the figure). The currently set delay time is a time obtained by multiplying the difference between the write address p and the read address q by the sampling frequency FS.
[0030]
That is, the delay time t1 is
Delay time t1 = (write address−read address) × (1 / sampling frequency)
It becomes.
[0031]
FIG. 3 is a diagram showing the operation of the audio delay control apparatus according to an embodiment of the present invention (addition operation of a silent part), and FIG. 4 is a case where the delay time of the audio delay control apparatus according to the embodiment of the present invention is increased. FIG. 5 is a diagram showing the operation when the delay time of the audio delay control apparatus according to the embodiment of the present invention is shortened. 6 is a diagram showing a control operation when the time for the delay memory 2 of FIG. 1 is increased, and FIG. 7 is a diagram showing a control operation when the time for the delay memory 2 of FIG. 1 is shortened. The operation of the audio delay control apparatus according to the embodiment of the present invention will be described with reference to FIGS.
[0032]
The input signal a of the input sound is converted into digital sound data b by the A / D converter 1 at the timing of the sampling frequency FS. The converted digital audio data b is written into the delay memory 2 by the write address p and the write signal d from the control unit 3.
[0033]
The control unit 3 outputs the read address q and the read signal e to be output to the delay memory 2 with the currently set delay setting time, that is, the delay time set by the delay control signal f.
[0034]
When the delay control signal f (delay time) does not change, the delayed audio data in the delay memory 2 passes through the memories 4 and 5 and is temporarily held in the output buffer memory 7 to be output data k as a D / A converter 8. The delayed sound is output as an output signal l. At this time, the level comparison detection unit 6 does not perform any detection.
[0035]
An operation when the delay control signal f (delay time) is changed during the operation in this state will be described. When the set time is changed longer than the current set time, as shown in FIG. 4, the silent part of sound (speech connection in normal conversation: breath part, etc.) is lengthened. However, if the difference in the setting change time (the difference between the current delay setting time and the delay time after the setting change) is suddenly performed at one silent portion, the user feels uncomfortable. Therefore, when the time of the silent part is lengthened, the control is performed several times. In the example shown in FIG. 4, the control is performed four times.
[0036]
This will be described in more detail below. The level comparison detection unit 6 compares the data in the memories 4 and 5 when the value of the delay control signal f is changed to the setting of f ′ (f <f ′). The level comparison detection unit 6 determines that there is no sound when the comparison data is smaller than the value of the prescribed signal level n.
[0037]
The data level difference between the memories 4 and 5 represents the amplitude of the signal. The smaller this value, the smaller the audio level (the smaller the amplitude). When the level difference is smaller than the prescribed signal level n determined to be silent, the level comparison detection unit 6 outputs a control signal g to the control unit 3 as a silent state (small sound).
[0038]
When the silent part is detected, the control unit 3 outputs data at the timing of the read signal e without counting up the read address q. This state is performed a predetermined number of times (FIG. 6 shows four operations).
[0039]
Thereafter, the control unit 3 counts up the read address q and outputs the delayed audio data c from the delay memory 2 to the memory 4. The memory 4 holds the delayed audio data c from the delay memory 2 and outputs the held audio data m to the memory 5. The memory 5 holds output data from the memory 4.
[0040]
The level comparison / detection unit 6 compares the data in the memories 4 and 5, determines that there is no sound when the level difference between the data in the memories 4 and 5 is smaller than the specified signal level n, and outputs a control signal g. The control unit 3 repeats the processing operation described above, and ends this operation when the delay control signal f ′ is reached (see FIG. 6).
[0041]
On the other hand, when the set time is changed to be shorter than the current set time, as shown in FIG. 5, the silent part of the sound is shortened. In this case as well, similar to the above control, if the difference in the set time is suddenly controlled, a sense of incongruity will be felt. Therefore, control is performed in several times. In the example shown in FIG. 5, the control is performed in four steps.
[0042]
This will be described in more detail below. The level comparison detection unit 6 compares the data in the memories 4 and 5 when the value of the delay control signal f is changed to the setting of f ′ (f <f ′). The level comparison detection unit 6 determines that there is no sound when the comparison data is smaller than the value of the prescribed signal level n.
[0043]
The level difference between the memories 4 and 5 represents the amplitude of the signal. The smaller this value, the smaller the audio level (the smaller the amplitude). When the level difference is smaller than the prescribed signal level n determined to be silent, the level comparison detection unit 6 outputs a control signal g to the control unit 3 as a silent state (small sound).
[0044]
When the control unit 3 detects a silent part by the control signal g from the level comparison detection unit 6, the count of the read address q for the delay memory 2 is counted up before the write signal (FS) to the output buffer memory 7 is output. Further, the read address q of the delay memory 2 is incremented by +1 and a read signal e is output.
[0045]
As a result, the audio data i output with the contents of the memory 5 holds the audio data of the next address i + 1. This deletes the contents of the memory 5 among the audio data of the memories 4 and 5 determined to be silent. This means that the delay time is shortened. The output data j to the output buffer memory 7 is repeatedly output until the value of the delay control data f from the outside is reached (see FIG. 7).
[0046]
By performing the control as described above, it is possible to eliminate the conventional problem of repeated output of the same sound or lack of sound when changing the setting of the delay control time. In addition, since the delay control is gradually performed, the setting change process can be performed without being aware of the delay time setting change process in the normal state.
[0047]
【The invention's effect】
As described above, according to the audio delay control device of the present invention, when the set time is longer than the current delay time, a silent part of the voice (low level fluctuation: small amplitude area) is detected and the silence is detected. By adding a silent signal to the portion, there is an effect that the phenomenon of repeated output of the same sound can be eliminated.
[0048]
In addition, according to another audio delay control device of the present invention, when the set time is shorter than the current delay set time, the silent part is detected and the silent part is deleted, thereby causing a problem such as missing sound. There is an effect that it can be eliminated.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an audio delay control apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a configuration example of a delay memory in FIG. 1;
FIG. 3 is a diagram illustrating an operation of an audio delay control apparatus according to an embodiment of the present invention.
FIG. 4 is a diagram illustrating an operation when the delay time of the audio delay control device according to the embodiment of the present invention is increased.
FIG. 5 is a diagram showing an operation when the delay time of the audio delay control apparatus according to the embodiment of the present invention is shortened.
FIG. 6 is a diagram showing a control operation when the time for the delay memory of FIG. 1 is lengthened.
7 is a diagram showing a control operation when the time for the delay memory of FIG. 1 is shortened. FIG.
FIG. 8 is a diagram for explaining a conventional control method when changing a delay time;
FIG. 9 is a diagram illustrating a problem when the delay time in the conventional method is increased.
FIG. 10 is a diagram showing a problem when the delay time in the conventional method is shortened.
FIG. 11 is a diagram for explaining a conventional audio data length changing method;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 A / D converter 2 Delay memory 3 Control part 4, 5 Memory 6 Level comparison detection part 7 Output buffer memory 8 D / A converter 8

Claims (5)

An audio delay control device that performs delay control using a delay memory that delays an input audio signal , the first memory temporarily holding output data from the delay memory, and the output data from the first memory A second memory that temporarily holds the data, and a comparison between the data held in the first memory and the data held in the second memory in response to a change in the set delay time of the audio signal An audio delay control apparatus comprising: a detection unit that detects a silent portion of the audio signal; and a control unit that controls to change the length of the silent portion detected by the detection unit. 2. The audio delay control apparatus according to claim 1, wherein the control means adds a silence signal to a silence portion of the audio signal when the set time is longer than a current delay time. The said control means deletes the said silence signal from the silence part of the said audio | voice signal, when setting time is made shorter than the present delay time, The said silence signal of Claim 1 or Claim 2 characterized by the above-mentioned. Audio delay control device. The control means according to claim 2 or claims, characterized in that as several times by equally dividing the time difference between the setting time of changing the delay time of the current changing the length of the silence Item 4. The audio delay control device according to Item 3 . 5. The audio delay control apparatus according to claim 1, wherein the audio delay control apparatus is used in an audio delay control system that delays an audio signal in response to an image delay of a video system in a broadcasting station.

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