JPH03224177A - Soundless processor - Google Patents

Abstract

PURPOSE:To efficiently use the recording capacity of a recording medium by preventing a recording control part from recording voice information under a soundless state on the recording medium in the case that the voice information is under the soundless state in a prescribed term. CONSTITUTION:The output side of an audio block 2 which digitally converts a voice signal is connected to an encoder 3. Then, a voice soundless decision part decides sound information and soundless information from the voice information. A system control part 4 counts the soundless information and judges that it is a sound in a minimum unit in the case that the counted value of the soundless information is smaller than a prescribed value in the read and write minimum unit of the sound information on the recording medium. When it is larger than the prescribed value, it is judged soundless. In the case that a signal showing the soundless is supplied from the control part 4, encoded data sent from the encoder 3 is controlled so that it is not recorded on a disk being the recording medium by a disk control part 5. Thus, the recording capacity of the recording medium is efficiently used.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device for encoding and recording digitized audio information, and relates to a silence processing device [Prior art and its problems] Audio information When encoding and recording on a recording medium such as a CD-1 or CD-ROM, conventionally, information in a silent state that does not include necessary audio information has also been encoded and recorded on the recording medium.

Therefore, there is a problem in that the recording capacity of the recording medium is consumed even by information in a silent state, and the storage capacity is not used efficiently.

The present invention was made to solve these problems, and an object of the present invention is to provide a silence processing device that can efficiently use the recording capacity of the recording medium.

[Means for Solving the Problems] The present invention comprises: a conversion section that digitally converts an audio signal; a utterance/non-speech determination section that determines utterance information and non-speech information from the audio information sent by the conversion section; System control that counts the silence information sent by the sound/silence determination unit and sends a signal indicating whether there is sound or silence for each minimum unit based on the counting result of the number of silences in the minimum unit of reading and writing audio information to the recording medium. and a recording control section that does not record the audio signal on the recording medium while the system control section is sending out a signal indicating silence.

[Operation] With this configuration, first, the utterance/non-speech determination unit determines utterance information and silence information based on the audio information. The system control unit counts the silence information sent by the utterance/non-sound determination unit, and if the count value of silence information is smaller than a predetermined value in the minimum unit of reading and writing audio information to the recording medium, the number of silence information in the minimum unit is It is determined that it is a sound, and if it is larger than a predetermined value, it is determined that there is no sound, and a signal to that effect is sent to the recording control section. The recording control unit does not record audio information on the recording medium while a signal indicating silence is supplied from the system control unit. Therefore, the recording capacity of the recording medium does not decrease due to silent information, and the recording capacity can be used efficiently.

[First Embodiment] In FIG. 1 showing an embodiment of the silence processing device of the present invention, a microphone l that converts audio information into an electrical signal is
It is connected to an audio block 2 for digitally converting an audio signal, and the output side of the audio block 2 is connected to an input terminal 10 of an encoder 3. The encoder 3 has a circuit configuration as shown in FIG. 2, and is a known circuit except for the addition of a silence/speech determining unit 15, and is a standard audio encoding circuit. It consists of: That is, the input terminal 10 to which the digitally converted audio signal sent out by the audio block 2 is supplied is connected to, for example, four types of predictors 11 to 14 that reduce the amount of information of the supplied audio signal. In this embodiment, since the encoder 4 uses a standard product as described above, four types of predictors are provided, but only the predictor 11 is used in this embodiment. It is. These predictors 11 to 14
Each of these includes two delay circuits 11a that delay the supplied audio signal, a multiplier 11b whose multiplication coefficient is CO, and a multiplier 11c whose multiplication coefficient is CI.

and an adder, the values of CO and CI in the predictor 11 are both 0, the value of CO in the predictor 12 is 0.9375, the value of CI is 0, and the value of CO in the predictor 13 is 1.796875, the value of C1 is 0, and the value of CO in the predictor 14 is 1.53125, C
The value of I is -0,859375. The output side of the predictor 11 is connected to the silence/speech determining section 15 and also to the input terminal of a selection switch 16 that selects the output signal of one of the predictors 11 to 14. Also, predictor 1
The output sides of 2 to 14 are connected to the input terminal of a selection switch 16. In this embodiment, the selection switch 16
Although the contact point is fixed to the output side of the predictor 11, it may be switched.

The output side of the selection switch 16 is an adder 21 and a multiplier 18.
It is connected to a worm dryer 19 which performs so-called rounding of the audio signal. Note that the quantizer 19 rounds the audio signal whose noise has been reduced by a known noise shaping section 20 shown in FIG. The noise shaping unit 20
As shown in the figure, the quantizer 19 has a known circuit configuration.
This circuit performs noise shaping based on the input side signal of the quantizer 19 and the output side signal of the quantizer 19, and sends the noise-shaped signal to the adder 21.

On the other hand, the silence/speech determining unit 15 measures the amplitude value of the output signal of the predictor 11, and uses this measurement value in advance to
As shown in FIG. 3, this circuit compares with the threshold value set in 5 and determines whether there is a sound or not for each sound unit, and the output side of the silence/sound determination section 15 - A system control unit 4 that counts the number of silent sound units from the signal for each sound unit sent by the sound determination unit 15, and determines that sector as a silent sector when the silence rate is equal to or greater than a predetermined value α. connected to.

Note that the sound unit is a unit representing a set of a predetermined number of samplings for encoding an audio signal, and for example, information corresponding to 28 samplings becomes information of one sound unit. Furthermore, a sector refers to a unit of aggregation of the above-mentioned sound units, and one sector is made up of N sound units, and the number of silent sound units present in one sector is expressed by the silence rate. for example,! If M silent sound units are counted in a sector, the silence rate is M/N.

The output side of the system control unit 4 is a disk control unit that controls recording of the audio signal supplied from the encoder 3 to a recording medium such as a compact disc (CD) according to a control signal sent by the system control unit 4. Connected to 5.

The operation of the silence processing device configured as described above will be explained below.

The audio information converted into an electrical signal by the microphone 1 is digitally converted by the audio block 2 and sent to each of the predictors 11 to 14 which are components of the encoder 3. In this embodiment, only the predictor 11 operates, and the predictor 11 reduces the amount of information of the encoded audio signal and quantizes the result via the selection switch 16 and the multiplier 18. The signal is sent to the device 19. Then, the audio signal whose noise has been reduced in the noise shaping section 20 is rounded in the quantizer 19, and is sent to the disk control section 5 as an output signal of the encoder 3.

Further, the output signal of the predictor 11 is sent to the silence/sound determination section 15, which monitors the output signal of the predictor 11 in units of one sound unit, and detects a threshold within one sound unit. If there is at least one output signal having an amplitude value exceeding the above value, that sound unit is determined to be a sound unit, and a signal to that effect is sent to the system control section 4. Note that if there is no output signal having an amplitude value exceeding the threshold value in one sound unit, that sound unit is determined to be a silent sound unit, and a signal to that effect is sent to the system control section 4.

The system control unit 4 counts silent sound units based on the supplied sound unit signals, calculates a silence rate from the counted value, and compares the calculation result with a predetermined value α.

If the silence rate value is equal to or greater than the predetermined value α, the system control unit 4 determines that the sector is a silent sector and sends a signal to that effect to the disk control unit 5. If the silent rate is less than the predetermined value α, the system control unit 4 determines that the sector is a sound sector, and sends a signal to that effect to the disk control unit 5.

When a signal indicating silence is supplied from the system control unit 4, the disk control unit 5 does not record the encoded data sent from the encoder 3 on the disk, which is a recording medium, and sets a flag indicating silence. only in the disk header information,
On the other hand, when a signal indicating a sound presence is supplied from the system control unit 4, the encoded data sent from the encoder 3 and a sound presence flag are recorded on the disk.

As described above, according to the silence processing device of this embodiment, when the signal sent from the microphone l is in a silent state, that information is not recorded on the recording medium, so that the recording capacity of the recording medium can be used efficiently. I can do it.

In addition, since the silence rate is calculated, the value is compared with a predetermined value, and a signal indicating silence or sound is created based on the result, the amplitude of the waveform of the audio signal may change only in a short section within l sector due to noise etc. If this is large, the section is determined to be silent, thereby preventing malfunctions of the device due to noise or the like.

In the above embodiment, a CD-ROM or a CD-1 is used as the recording medium, but the present invention is not limited to this, and any medium that records signals processed as digital signals may be used. The second embodiment shown below shows such a case.

[Second Embodiment] In FIG. 4 showing a second embodiment, the same components as those shown in FIG.

The output side of the utterance/silence determination section 15 provided in the encoder 3 is connected to the system control section 4, and the output side of the system control section 4 is connected to the memory management circuit 30 to which the output side of the encoder 3 is connected. be done. The output side of the memory management circuit 30 includes a voice/silence flag memory 41 and an ADPCM data memory 42.
It is connected to a storage device 40 having a.

The memory management circuit 30 stores the data of the sector in accordance with the sound/silence determination signal for each sector supplied from the system control unit 4 for the sector determined to be sound.
The data of the sector is sent to the storage device 40 so as to be stored in the ADPCM data memory 42 within 0, and
This circuit sends the utterance/silence determination signal supplied from the utterance/silence determination section 15 to the storage device 40 .

The storage device 40 records the sound/silence determination signal supplied from the memory management circuit 30 in the sound/silence flag memory 41 in correspondence with each sector, and records the sound/silence determination signal supplied from the memory management circuit 30 in the sound/silence flag memory 41 . This is a circuit for recording audio data in the ADPCM data memory 42.

The operation of the silence processing device configured as described above will be explained below. Note that the signal processing in the audio block 2, encoder 3, and system control unit 4 of the audio signal supplied from the input terminal 50, which is the signal processing until the signal is supplied to the memory management circuit 30, is the same as the above-mentioned first method. Since this is the same as the embodiment, the explanation will be omitted.

The memory management circuit 30 is informed by the system control unit 4 that, for example, the first and second sectors are silent, and the third sector is silent.

If the 4th and 5th sectors have sound, the 6th sector has no sound, etc., a sound/silence determination signal is supplied.
The memory management circuit 30 sends out this voice/no-sound determination signal to the storage device 40 as it is, and also sends out the audio data of the 3rd, 4th, 5th, and 7th sectors, which are sound sectors, to the storage device 40.

As shown in FIG. 5, the storage device 40 records the sound/silence determination signal supplied from the memory management circuit 30 in the sound/silence flag memory 41 in association with each sector.
3, 4, 5.7 with sound in the PCM data memory 42
Record the audio data of the th sector. Note that the sound/silence flag memory 41 is used to indicate where a silent sector is located when an audio signal is reproduced.

In this way, even in the case of a storage device such as a semiconductor memory instead of a CD-ROM etc., as in this embodiment,
By recording in the memory the audio data of only the sectors determined to be active, the storage capacity of the memory can be used efficiently.

[Effects of the Invention] As detailed above, according to the present invention, when the audio information is silent for a predetermined period, the recording control unit does not record the audio information at that time on the recording medium. The recording capacity can be used efficiently without being consumed by silent information.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the silence processing device of the present invention, FIG. 2 is a block diagram showing the configuration of the encoder shown in FIG. 1, and FIG. 3 is the system shown in FIG. 1. A diagram for explaining the operation of the control section, FIG. 4 is a block diagram showing the configuration of another embodiment of the silence processing device of the present invention,
FIG. 5 is a block diagram showing the configuration of the storage device shown in FIG. 4. 2... Audio block, 3... Encoder, 4...
...System control section, 5...Disk control section, 15
. . . Speech/non-sound determination unit, 30 . . . Memory management circuit, 4
0...Storage device.

Claims (1)

[Claims] (1) A conversion unit that digitally converts an audio signal, a utterance/non-speech determination unit that determines voice information or non-speech information from the audio information sent out by the conversion unit, and silence information sent out by the utterance/non-speech determination unit. a system control unit that performs counting and sends a signal indicating whether there is a sound or no sound for each minimum unit based on the result of counting the number of silences in the minimum unit of reading and writing audio information to a recording medium; 1. A silence processing device comprising: a recording control unit that does not record audio signals on a recording medium while transmitting a signal indicating the sound.