JPH09138698A - Sound recording/reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record more the sound data by reducing the information amounts of the recorded sound data according to the priority when the recording capacity of the sound data are insufficient when the capacity of a recording medium is limited. SOLUTION: When a sound signal is inputted from a sound recording means 11, a recording remaining amounts detection means 13 detects the free capacity of the recording medium 12. A priority decision control means 14 decides the priority for the sound signal based on the prescribed importance, and an information reduction means 55 controls the information amounts of the recorded sound data. Then, the input sound data are recorded on the enlarged free capacity. A reproducing means 16 reproduces all the sound data so that the contents are found.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio recording / reproducing apparatus for efficiently recording and reproducing an audio signal on a recording medium having a limited capacity.

[0002]

2. Description of the Related Art An audio recording / reproducing apparatus for recording as many audio signals as possible on a recording medium having a limited capacity has been put into practical use. Hereinafter, a conventional audio recording / reproducing apparatus will be described with reference to FIG. FIG. 6 is a block diagram showing the basic configuration of a conventional audio recording / reproducing apparatus. As shown in the figure, the audio recording / reproducing apparatus includes a high efficiency encoding / encoding means 60, a recording / reproducing means 61, a recording medium 62, and a high efficiency encoding / decoding means 63.

The operation of the audio recording / reproducing apparatus having such a configuration will be described. First, when recording a voice signal, the high-efficiency coding encoder means 60 is designed to record the input voice signal for as long as possible.
An audio signal is encoded using a predetermined high efficiency encoding algorithm. Next, the recording / reproducing device 61 records the high-efficiency coded audio signal on the recording medium 62. Also,
When reproducing the audio signal, the recording / reproducing means 61 reads out the high efficiency coded data from the recording medium 62. Then, the high-efficiency coding / decoding means 63 performs a decoding process of the read data to reproduce the audio signal.

[0004]

However, in the above-mentioned configuration, the bit rate is reduced by the high-efficiency coding and the processing is performed regardless of the capacity of the recording medium 62. In this case, the recordable time length of the audio signal can be changed by setting the bit rate, but the optimum bit rate can be set unless the recordable time length is known in advance. Can not.
In addition, there is a problem in that the contents are uniformly compressed without considering the content of the audio signal and the importance of the audio information.

For this reason, in an apparatus that cannot store a large capacity in the recording medium, it is prioritized to set the bit rate to a low value in advance so that the time length is as large as possible. Therefore, even if there is a free space in the recording medium, it is possible to record / reproduce only an audio signal accompanied by quality deterioration due to the high-efficiency coding algorithm.

The present invention has been made in view of the above conventional problems, and when a recording medium has a free space, an audio signal is recorded so as not to cause quality deterioration. If the free space of the recording medium is small, more audio signals are newly recorded by reducing the information amount of these audio data in consideration of the priority of each recorded audio data. It is an object of the present invention to realize an audio recording / reproducing device that enables the above.

[0007]

In order to solve this problem, the audio recording / reproducing apparatus of the present invention detects the free space of the recording medium by the remaining recording amount detecting means. The priority decision control means decides the priority for the voice signal based on the degree of importance set in advance. Then, the information amount reducing means is instructed to reduce the information amount of the audio data recorded on the recording medium. The information amount reducing means performs the information amount reducing process on the low priority audio data recorded on the recording medium. This allows more audio data to be recorded on the recording medium having a limited capacity.

Priority items include time of recording, contents of recorded audio source, user who recorded, frequency of reproduction after recording, ratio of audio section in audio signal, and audio signal. It is determined in consideration of one or more of the speaking speed of the voice of the person included, the manual addition by the user to the individual file, and the like. As the information amount reducing means, one or more of an information source coding means, a high efficiency coding means, a silent section deleting means, a time axis compression means, etc. are used for processing.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present application, a recording medium for holding data including voice, a voice recording means for recording an input voice signal on the recording medium, and a recording medium recorded on the recording medium. Reproducing means for reproducing data and converting it into an audio signal, recording residual quantity detecting means for detecting a free space of data on the recording medium, priority of the audio signal is determined, and recorded on the recording medium based on the priority. Recording medium using priority determination control means for controlling so as to reduce the amount of information of the audio data, and information source encoding capable of reversible compression / decompression based on the priority instructed by the priority determination control means. The amount of information of the audio data already recorded on the recording medium is reduced and the data is re-recorded on the recording medium to increase the free space of the recording medium. And information source coding means for, and is characterized in that it comprises a.

With this configuration, the information source coding means uses the information source coding capable of reversible compression / expansion based on the priority indicated by the priority determination control means, and the audio data already recorded on the recording medium. Reduce the amount of information. Then, the free space of the recording medium is increased by re-recording the data on the recording medium.

According to a seventh aspect of the present invention, a recording medium for holding data including voice, a voice recording means for recording an input voice signal on the recording medium, and a data recorded on the recording medium are reproduced. And a reproducing means for converting into an audio signal,
A recording remaining amount detecting means for detecting a free space of data of the recording medium, and a priority for determining a priority of an audio signal and controlling so as to reduce the information amount of the audio data recorded on the recording medium based on the priority. Based on the priority indicated by the decision control means and the priority decision control means, the information amount of the audio data already recorded on the recording medium is reduced by using the high efficiency encoding, and the data is reproduced on the recording medium. A high-efficiency encoding means for increasing the free space of the recording medium by recording.

With such a configuration, the high-efficiency coding means reduces the information amount of the audio data already recorded on the recording medium by using the high-efficiency coding based on the priority indicated by the priority determination control means. Then, the free space of the recording medium is increased by re-recording the data on the recording medium.

According to a thirteenth aspect of the present invention, a recording medium for holding data including voice, a voice recording means for recording an input voice signal on the recording medium, and a data recorded on the recording medium are reproduced. Reproducing means for converting into a sound signal, a remaining recording amount detecting means for detecting a free space of the data of the recording medium, a priority of the sound signal, and of the sound data recorded in the recording medium based on the priority. Priority determination control means for controlling so as to reduce the amount of information, and based on the priority instructed by the priority determination control means, by deleting the unnecessary silent section of the audio signal, the voice already recorded on the recording medium A silent zone in which the amount of information of data is reduced and the free space of the recording medium is increased by re-recording the data in the recording medium. It is characterized in that it comprises a deletion means.

With such a configuration, the silent section deleting means deletes the unnecessary silent section of the audio signal based on the priority instructed by the priority determination control means, whereby the information of the audio data already recorded on the recording medium is recorded. Reduce the amount. Then, the free space of the recording medium is increased by re-recording the data on the recording medium.

According to a twentieth aspect of the invention of the present application, a recording medium for holding data including voice, a voice recording means for recording an input voice signal on the recording medium, and reproducing the data recorded on the recording medium. Reproducing means for converting into a sound signal, a remaining recording amount detecting means for detecting a free space of the data of the recording medium, a priority of the sound signal, and of the sound data recorded in the recording medium based on the priority. Priority determination control means for controlling so as to reduce the amount of information, and based on the priority instructed by the priority determination control means, by using a time axis compression process to reduce the recording time length of the audio signal, Reduce the amount of information in the audio data already recorded,
And a time axis compression means for increasing the free space of the recording medium by re-recording the data in the recording medium.

With such a configuration, the time base compression means is already recorded on the recording medium using the time base compression for reducing the recording time length of the audio signal based on the priority indicated by the priority determination control means. Reduce the amount of information of the voice data. Then, the free space of the recording medium is increased by re-recording the data on the recording medium.

According to a twenty-eighth aspect of the present invention, a recording medium for holding data including voice, a voice recording means for recording an input voice signal on the recording medium, and a data recorded on the recording medium are reproduced. Reproducing means for converting into a sound signal, a remaining recording amount detecting means for detecting a free space of the data of the recording medium, a priority of the sound signal, and of the sound data recorded in the recording medium based on the priority. Based on priority determination control means for controlling so as to reduce the amount of information, and the priority indicated by the priority determination control means, the information amount of audio data already recorded on the recording medium is reduced, and the data is recorded as described above. And an information amount reducing means for increasing the free space of the recording medium by re-recording on the medium. It is.

With such a configuration, the information amount reducing means reduces the information amount of the audio data already recorded on the recording medium based on the priority instructed by the priority determination control means. Then, the free space of the recording medium is increased by re-recording the data on the recording medium.

(First Embodiment) An audio signal recording / reproducing apparatus according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing the arrangement of the audio recording / reproducing apparatus of this embodiment. As shown in this figure, the audio recording / reproducing apparatus includes an audio recording means 11, a recording medium 12, a recording remaining amount detecting means 13, and a priority determination control means 1.
4, the information source coding means 15 and the reproducing means 16 are included.

The voice recording means 11 is a means for recording an input voice signal on the recording medium 12, and when the voice recording / reproducing apparatus includes a personal computer, the voice signal input interface has a part of its function. Carry. The recording medium 12 holds data including voice, and may be a semiconductor memory, a hard disk, a flexible disk, an optical disk, or the like. The reproducing means 16 is the recording medium 12
It is a means for reproducing the data recorded in and converting it into an audio signal. The recording remaining amount detecting means 13 is a means for detecting the free space of the data already recorded on the recording medium 12, and the information thereof is given to the priority determination control means 14.

The priority decision control means 14 decides the priority for the voice signal based on a preset method, and holds or reduces the information amount of the voice data recorded in the recording medium 12 as it is as the information source of the control signal. This is given to the encoding means 15. The information source coding unit 15 reduces the information amount of the audio data already recorded on the recording medium 12 based on the priority instructed by the priority determination control unit 14 using the information source coding so as to reversibly compress the information amount. It is a thing. Then, the information source coding means 15 re-records the coded audio data in the recording medium 12.

The main purpose of the audio recording / reproducing apparatus of this embodiment is to record / reproduce an audio signal. However, when an audio signal is recorded on the recording medium 12, it is necessary according to the amount of information. Will occupy a storage capacity of In view of this, the present apparatus reduces the amount of information of already recorded audio data to allow new recording when it becomes necessary to record an audio signal exceeding the capacity of the recording medium 12. Is.

The voice recording means 11 first converts the input voice signal into a format recordable on the recording medium 12 and records it on the recording medium 12. At the time of the initial recording, it shall be recorded in a high quality state so as not to impair the characteristics of the audio signal. The remaining recording amount detecting means 13 monitors the free space of the recording medium 12 as needed. Then, the priority determination control means 14 controls the information source coding means 15 so as to reduce the information amount for the voice data having the lowest priority among the voice data already recorded, based on the information of the predetermined priority. Control.

The information source coding means 15 performs information source coding on the voice data file designated by the priority determination control means 14 to reduce the information amount of the voice data. Then, the data converted here is recorded again on the recording medium 12. This information source coding method includes, for example, the Lampel-Zip Coding method and the Huffman Coding method. With this encoding method, it is possible to reversibly restore the encoded audio data to the original audio data. However, in the decompression (decoding), some processing delay occurs due to the calculation. Therefore, it takes a little waiting time until the sound is output during the reproduction.

When the information indicating that the free space of the recording medium 12 is not yet sufficiently increased is given from the remaining recording amount detecting means 13, the priority determination control means 14 selects the voice data having a low priority again, and determines the information amount. To instruct to perform the information source coding process for reducing. Then, with respect to the audio data whose information amount has been reduced by the information source encoding means 15, the reproducing means 16 restores the decompressed audio data to reproduce the audio.

Various factors can be considered for determining the priority. First, a case where the priority is set according to the recording time will be described. When recording audio data, record the time. In an answering machine or the like, it is often the case that the newest recorded time is more important. Therefore, by setting a high priority for the latest voice information, the information amount of old data is reduced. It is also effective in some cases to delete the entire data after a certain amount of time has passed.

Next, a case where priority is set according to the contents of the recorded audio source will be described. For example, music data has a high priority, and human speech data has a low priority. In this case, the music data can be immediately reproduced without delay, but the speech data of a person takes a long time to be decompressed, so the music data is reproduced after a while. In this way, setting the music data with priority is also an example.

Next, a case will be described in which the priority is set according to the user who has recorded. in this case,
Similar to the usage environment of a large-scale computer or the like, the priority is set high for users of a specific group who perform the same work as themselves, and low for other users. In such a setting method, the colleagues who perform the same job are prioritized, and the information of other people is compressed. in this way,
It is also an example to preferentially allocate the information amount to the voice data of the same work group.

Next, a case will be described in which the priority is set according to the frequency of reproduction after recording. For example, the priority is set to increase each time the recorded audio data is reproduced. Further, the priority is lowered for the voice data which has not been reproduced, and the information amount of the voice data is reduced. In this case, the voice data that is not used is considered to be of low value, and the amount of information is reduced and retained in the recording medium, or finally deleted.

Next, a case where the user manually sets priorities for individual files will be described. In this case, the user himself / herself who records the voice data sets the priority by determining the importance of the voice data each time without being bound by the above-mentioned rules.
Such a priority setting method is effective when exceptional priority settings frequently occur. That is, an example is a case where an operation of setting a special priority to a part of the audio data is permitted during use in the above rule.

As described above, according to the present embodiment, the free space of the recording medium is monitored at any time, and the information amount is reduced and the information is compressed by the information source coding according to the predetermined priority. Therefore, the free space of the recording medium can be substantially increased. Also, the priority setting is the time when recording is performed, the content of the recorded audio source, the user who performed the recording, the frequency of playback after the recording, and the user manually assigns to each file,
Etc. are decided in consideration. In this way, the required amount of information can be extracted from the low priority corresponding to the importance, and the high importance can be immediately reproduced without decompression.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a block diagram showing the configuration of the audio recording / reproducing apparatus of this embodiment, and the same parts as those in the first embodiment are designated by the same reference numerals.
As shown in the figure, the voice recording / reproducing apparatus is provided with a voice recording means 1
1, a recording medium 12, a remaining recording amount detection means 13, a priority determination control means 14, a high efficiency coding means 25, and a reproduction means 16.

The voice recording means 11 first converts the input voice signal into a format recordable on the recording medium 12 and records it on the recording medium 12. At the time of the initial recording, it shall be recorded in a high quality state so as not to impair the characteristics of the audio signal. The remaining recording amount detection means 13 monitors the free space of the recording medium 12 as needed. Then, the priority determination control means 14 determines, based on the information on the predetermined priority,
The high-efficiency encoding means 25 is controlled so as to reduce the bit rate for the voice data having the lowest priority among the voice data already recorded.

The high-efficiency coding means 25 performs high-efficiency coding on the audio data file designated by the priority determination control means 14 to reduce the bit rate of the audio data. Then, the data converted here is recorded on the recording medium 12. This high-efficiency coding method reduces the redundancy of a speech waveform, and for example, ADP
CM, CELP, etc. are used. With such an encoding method, the audio data cannot be reversibly restored to the original audio data, and the reproduction quality deteriorates.

The degree of quality deterioration generally increases as the bit rate after reduction decreases. Then, when the information indicating that the free space of the recording medium 12 is not yet sufficiently increased is given from the remaining recording amount detecting means 13, the priority determination control means 14 selects again the audio data having a low priority and reduces the bit rate. Instruct to perform high-efficiency encoding processing for And reproduction means 1
6 decodes the audio data reduced to the given bit rate and reproduces the audio.

Various factors can be considered for determining the priority. First, a case where the priority is set according to the recording time will be described. When recording audio data, record the time. In an answering machine or the like, it is often the case that the newest recorded time is more important. Therefore, the voice data is stored as it is by setting the priority to the latest voice information, and the bit rate is reduced by the high efficiency encoding means 25 for the old data. It is also effective in some cases to delete the entire data after a certain amount of time has passed.

Next, a case will be described in which the priority is set according to the contents of the recorded audio source. For example, music data has a high priority, and human speech data has a low priority. In this case, a high-efficiency coding method with a relatively high bit rate is adopted so as to reduce quality deterioration of music data. On the other hand, for the data of human speech, a high efficiency coding system with a relatively low bit rate assuming a vocal tract model is used. By adaptively setting the encoding method in this way, it is possible to reduce the amount of information about both music and human voice without difficulty.

Next, a case will be described in which the priority is set according to the recording user. in this case,
Set a high priority for users of external customers,
Give a low priority to internal group users. In such a setting method, the voice data of the external customer is left as it is, and high-efficiency encoding is performed so as to reduce the bit rate of the internal user. By setting in this way, the audio data of the external customer can be maintained without quality deterioration, and the bit rate of the internal user can be reduced, so that the information amount of the entire recording medium 12 can be reduced.

Next, a case will be described in which the priority is set according to the frequency of reproduction after recording. For example, the priority is set to increase each time the recorded audio data is reproduced. Also, the priority of audio data that has never been reproduced is kept low. If the free space of the recording medium 12 is insufficient in this state, a process of reducing the information amount of any audio data is performed. In this case, consider that the unused audio data is of low value, and either reduce the bit rate and retain it on the recording medium, or
Eventually delete it.

Next, a case where the user manually sets priorities for individual files will be described. In this case, the user himself / herself who records the voice data sets the priority by determining the importance of the voice data each time without being bound by the above-mentioned rules.
Such a priority setting method is effective when exceptional priority settings frequently occur. That is, an example is a case where an operation of setting a special priority to a part of voice data is permitted during use according to the above rule.

As described above, according to the present embodiment, the free space of the recording medium is monitored at any time, and the free space of the recording medium is obtained by performing the information compression by the high efficiency encoding according to the predetermined priority. Can be substantially increased. In addition, the priority can be set by the time of recording, the classification according to the contents of the recorded audio source, the user who recorded, the frequency of playback after recording, the user's manual attachment to individual files, etc. To decide. In this way, the necessary amount of information can be extracted from the low priority corresponding to the importance, and the high importance can reproduce the voice or music without causing deterioration due to compression.

(Third Embodiment) An audio recording / reproducing apparatus according to a third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing a configuration diagram of the audio recording / reproducing apparatus of the present embodiment, and the same parts as those in the first embodiment are designated by the same reference numerals. In the figure, the audio recording / reproducing apparatus includes an audio recording unit 11, a recording medium 12, a recording remaining amount detecting unit 13, a priority determination control unit 14, a silent section deleting unit 35, and a reproducing unit 16.

The voice recording means 11 first converts the input voice signal into a format recordable on the recording medium 12 and records it on the recording medium 12. At the initial recording, the entire input audio signal shall be recorded without being deleted.
The remaining recording amount detecting means 13 monitors the free space of the recording medium 12 as needed. Then, the priority determination control means 14
Based on the information of the predetermined priority, the silent section deleting means 35 is controlled so as to delete the unnecessary silent section from the voice data having the lowest priority among the already recorded voice data.

The silent section deleting means 35 detects an unnecessary silent section contained in the voice data file designated by the priority determination control means 14, deletes the section, and cuts out only the necessary voice section data. Then, it is converted into audio data with a reduced amount of information and recorded again on the recording medium 12. Always 30-40 for human voice waveforms
Since a silent section of about% is included, it is possible to significantly reduce the amount of information by deleting this unnecessary silent section. However, as a method of detecting a silent section, an amplitude level, the number of zero crossings, or a method using an autocorrelation coefficient is used. This makes it possible to obtain a silent section for most of the voice data. However, it is difficult to detect the section when the background noise is not stationary or a voice other than the target voice is included.

Therefore, as for the voice data having a high degree of importance, the voice data is recorded as it is without deleting the silent section as much as possible. For voice data with a low priority, the recording medium 1 is changed to data in which a silent section is deleted in order to create a free space in the recording medium 12.
Rerecord to 2. Then, when the recording remaining amount detecting means 13 gives the information indicating that the free space of the recording medium 12 has not yet been sufficiently increased, the priority determination control means 14 selects another voice data having a low priority again and outputs no sound. Instruct to perform the process for deleting the section. Then, the reproducing means 16 reproduces the given audio data.

Various factors can be considered for determining the priority. First, a case where the priority is set according to the recording time will be described. When recording audio data, record the time. In an answering machine or the like, it is often the case that the newest recorded time is more important. Therefore, the latest voice information is set to a high priority and stored as it is. Further, the silent section deleting means 35 deletes the data of the silent section from the old data. It is effective in some cases to delete the entire data after a certain amount of time has passed. As another method, a method of limiting the number of seconds of the voice section of the voice data and re-recording is conceivable.

Next, a case will be described in which the priority is set according to the contents of the recorded audio source. Here, it will be described that whether or not the silent section of the audio source can be easily detected in advance. For example, in the case of music data, silent sections should not be deleted. Therefore, the highest priority is set, and for sports broadcasts or the like where background noise is expected to be high, the priority is set slightly higher. Also, the data of human-speech voice, which is expected to be less affected by background noise, is set to the lowest value. In this case, no silent section is deleted from the music data. Further, the less the influence of the background noise, the more the silent section is deleted. By setting in this way, it is possible to reduce the amount of information about both music and human voice without difficulty.

Next, a case will be described in which the priority is set according to the user who recorded. In this case, for example, a user of an external customer is set to a high priority, and a user of an internal group is set to a low priority. It is assumed that the voice data of an external customer is not only obtained from an ideal environment but also has high background noise. Therefore, the voice data is recorded as it is as much as possible, and the data is deleted in the silent section of the internal user. By setting in this way, it is possible to keep the voice data of the external customer without sound break and reduce the information amount of the entire recording medium 12 by deleting the silent section of the internal user.

Next, a case will be described in which the priority is set according to the frequency of reproduction after recording. For example, the priority is set to increase each time the recorded audio data is reproduced. The priority of audio data that has never been reproduced is kept low. When the free space of the recording medium 12 is insufficient in this state, it is considered that the unused voice data is of low value, and the silent section is deleted and the voice data is re-recorded and held in the recording medium 12. Finally, these data may be deleted.

Next, a case where the user manually sets priorities for individual files will be described. In this case, the user himself / herself who records the voice data sets the priority by determining the importance of the voice data each time without being bound by the above-mentioned rules.
Such a priority setting method is effective when exceptional priority settings frequently occur. That is, an example is a case where an operation of setting a special priority to a part of the audio data is permitted during use in the above rule.

Next, the case where priority is set according to the ratio of the voice section in the voice signal will be described. At the time of recording, a voice section and a silent section are discriminated for each voice data, and then the ratio of the voice section is calculated. The higher the ratio of the voice section, the higher the priority. When the priority is set in this way, the priority is set lower as the number of silent sections is increased, so that it is possible to rationally select the processing for reducing the information amount. Further, by performing the processing in descending order of the ratio of the silent section, the processing effect becomes larger for the first data, and the amount of information can be effectively reduced. Note that, here, although the example in which the priority is set from the ratio of the voice section is shown, the priority can be similarly determined from the ratio of the silent section.

As described above, according to this embodiment, the free space of the recording medium is monitored at any time, and the processing for deleting the voice data in the silent section is performed according to the predetermined priority. The free space can be substantially increased. In addition, the priority can be set according to the recording time, the classification according to the contents of the recorded audio source, the user who recorded, the frequency of playback after recording, the manual addition of the user's individual file, and the audio. It is determined in consideration of the ratio of the voice section in the signal. In this way, the necessary information amount can be extracted from the low priority corresponding to the importance, and the high importance can reproduce the voice or music without causing deterioration due to compression.

(Fourth Embodiment) An audio recording / reproducing apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 4 is a block diagram showing the configuration of the audio recording / reproducing apparatus in this embodiment, and the same parts as those in the first embodiment are designated by the same reference numerals. As shown in the figure, the audio recording / reproducing apparatus comprises an audio recording means 11, a recording medium 12, a recording remaining amount detecting means 13, a priority determination control means 14, a time axis compression means 45 and a reproducing means 16.

The voice recording means 11 first converts the input voice signal into a format recordable in the recording medium 12 and records it in the recording medium 12. At the time of initial recording, the input audio signal shall be recorded without being processed. The remaining recording amount detecting means 13 monitors the free space of the recording medium 12 as needed. Then, the priority determination control means 14 causes the time axis compression means 45 to reduce the recording time length for the voice data with the lowest priority among the voice data already recorded based on the information of the predetermined priority. Control.

The time axis compression means 45 performs processing for increasing the reproduction speed of the audio data file designated by the priority determination control means 14 without changing the pitch of the sound. Then, in order to shorten the recording time, it is converted into audio data with a reduced amount of information, and this data is recorded again in the recording medium 12. Human beings may change their speaking speed according to the quality of information they want to communicate and the other party. Similarly, the information receiving side adapts to various voices having different speeds. Since the audio data whose speed has been increased by the time axis compression is reprocessed and re-recorded, the amount of information can be substantially reduced.

The time axis compression is performed by the TDHS method (for example, weighting addition of waveforms using pitch information) (for example,
Sadahiro Furui's "Digital Speech Processing" Tokai University Press, etc.) or a method of performing weighted addition of fixed-length waveforms using a correlation function (Japanese Patent Application No. 5-149224, etc.)
Etc. are available. In addition, when the time axis compression is performed, another feature is that the voice information can be reproduced in a short time and can be efficiently listened to. However, the greater the degree of time axis compression, the more difficult it becomes to understand the contents of the voice. Therefore, time axis compression is not performed for voices with high priority, or the time axis compression ratio is not increased even if they are performed. For voices with low priority, the time base compression is performed to shorten the recording time length and the voice data is re-recorded.
A free space is created in the recording medium 12.

Then, the priority decision control means 14
When the information indicating that the free space of the recording medium 12 has not been sufficiently increased is given from the remaining recording amount detecting means 13,
Then, another voice data having a lower priority is selected again, and an instruction is given to perform the time axis compression process. Then, the reproducing means 16 reproduces the given audio data. Reproduction means 1
In 6, it is also possible to obtain the original speed voice by adding the time axis expansion process. However, since the time axis expansion processing is newly added, the degree of quality deterioration will increase, so
In some cases, it may be easier to hear by reproducing the time-axis-compressed audio data as it is.

Various factors can be considered for determining the priority. First, a case where the priority is set according to the recording time will be described. When recording audio data, record the time. In an answering machine or the like, it is often the case that the newest recorded time is more important. Therefore, the latest voice information is set with a high priority and stored as it is, and the time axis compression means 45 shortens the recording time length of old data. It is effective in some cases to delete the entire data after a certain amount of time has passed.

Next, a case where priority is set according to the contents of the recorded audio source will be described. For example, music data loses its artistry when compressed on the time axis, so the priority is set to the highest. Also, for sources that can be heard even if the speed is a little faster in news, etc., set the priority higher. As a result, music has a low degree of time-axis compression, and human voice has a high degree of time-axis compression. By setting in this way, it is possible to reduce the amount of information about both music and human voice without difficulty.

Next, a case will be described in which the priority is set according to the user who recorded. in this case,
For example, users of external customers are given high priority, and users of internal groups are given low priority. This setting is not limited to when the external customer's voice data is obtained from an ideal environment,
This is because it is assumed that the audio is hard to hear, and it is desired to record the audio as it is without applying time axis compression so that it is not overlooked. On the contrary, since the internal user can hear the content of the story again, the time axis compression is performed. By setting in this way, it is possible to keep the external customer's voice data from leaking and to reduce the information amount of the internal user's voice data by time axis compression.

Next, the case where the priority is set according to the frequency of reproduction after recording will be described. For example, the priority is set to increase each time the recorded audio data is reproduced. For audio data that has never been reproduced, the priority remains low. If the free space of the recording medium 12 is insufficient in this state, a process of reducing the information amount of any audio data is performed. In this case, the voice data that is not used is considered to be of low value, and the recording time length is reduced by time axis compression to re-hold the data in the recording medium 12. Finally, such data may be deleted.

Next, a case where the user manually sets priorities for individual files will be described. In this case, the user himself / herself who records the voice data sets the priority by determining the importance of the voice data each time without being bound by the above-mentioned rules.
Such a priority setting method is effective when exceptional priority settings frequently occur. That is, an example is a case where an operation of setting a special priority to a part of the audio data is permitted during use in the above rule.

Next, a case where priority is set according to the ratio of the voice section in the voice signal will be described. In general, there is a correlation between the ratio of a large amount of silent intervals in a human voice signal and the speaking rate (“Development of voice speed conversion processing device into educational system equipment” Nakanishi, Misaki, Yamaguchi, 1994 scientific research. Subsidy test study (B) Research report: Development of new listening education / learning system by controlling foreign language (English) voice time axis (see p.39). In other words, it is considered that those with a high vocalization rate have a small proportion of silent sections, while those with a slow vocalization rate have a large proportion of silent sections. Then, at the time of recording the voice data, the voice section and the silent section are discriminated, the ratio of the voice section is calculated, and the larger the ratio of the voice section is, the higher the priority is set.

With this setting, the priority decreases as the number of silent intervals increases, so that the process of reducing the amount of information by compressing the time axis becomes easier. Although the vocalization speed is relatively high due to time axis compression,
Since the rate of uttering the original voice data is slow, the effect is small. By setting in this way, it is possible to reduce the effective amount of information by performing the processing in order from the one with the largest proportion of the silent section, that is, the one with the slowest utterance speed.
Note that, here, although the example in which the priority is set from the ratio of the voice section is shown, the priority can be similarly determined from the ratio of the silent section.

Next, a case will be described in which the priority is set according to the utterance speed of the voice of the person included in the voice signal. If the standard speed of human vocalization is 1.0,
It is said to change in the range of 0.7 to 1.5. The time axis compression process can be processed at any speed. Therefore, at the time of recording the voice data, the vocalization speed of the person is calculated, and the higher the vocalization speed, the higher the priority is set. When the priority is set as described above, the lower the utterance speed is, the lower the priority is, and by shortening the recording time by the time axis compression process, it is easy to perform the process of reducing the information amount. Although the speech rate is relatively high due to the time axis compression, the influence is small because the speech rate of the original voice data is slow. By setting in this way, it is possible to perform processing in order from the slowest utterance speed, and to reduce the effective amount of information.

As described above, according to the present embodiment, the free space of the recording medium is monitored at any time, and the time axis compression process is performed in order to reduce the amount of information in accordance with the predetermined priority. It is possible to substantially increase the free capacity of. Also, the priority setting is
Recording time, classification according to the content of the recorded audio source, user who recorded, frequency of playback after recording, user's giving manual to individual file, audio section of audio signal The rate is determined in consideration of the ratio, the speech rate of the human voice included in the voice signal, and the like. In this way, the required amount of information can be extracted from the one with a low priority corresponding to the importance, and the one with a high importance can reproduce the voice with less deterioration due to compression.

(Fifth Embodiment) An audio recording / reproducing apparatus according to a fifth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a block diagram showing the configuration of the audio recording / reproducing apparatus of this embodiment. As shown in the figure, the audio recording / reproducing apparatus includes an audio recording unit 11, a recording medium 12, a recording remaining amount detecting unit 13, a priority determination control unit 14, an information amount reducing unit 55, and a reproducing unit 16.
The specific operation is basically the same as the first operation described above.
~ It is similar to the fourth embodiment.

The information amount reducing means 55 performs the information source coding processing, the high efficiency coding processing, the silent section deletion processing, and the time axis compression processing on the audio data file designated by the priority determination control means 14 in parallel. The data is converted into audio data having a reduced amount of information and recorded in the recording medium 12. The priority determination control means 14 more finely controls which of these respective processes is to be executed and to what degree according to the nature of the audio data. Therefore, the silence removal process is mainly applied to the voice that includes many silent periods, the high-efficiency coding process is applied to the ideal voice, and the time-base compression process is applied to the voice that can be heard at a high speaking speed. multiply. In this way, data is processed and processed according to the nature of the audio signal.

In determining the priority, the recording time, the contents of the audio source, the user who recorded the data, the frequency of the reproduction after the recording, and the manual for the individual file of the user are linked with the information amount reducing means. The priority is set by comprehensively giving, the ratio of the voice section in the voice signal, and the speaking speed of the voice of the person included in the voice signal. By determining the priority by integrating these items, it is possible to reduce the effective amount of information that matches the characteristics of the audio signal.

As described above, according to this embodiment, the free space of the recording medium 12 is monitored at any time, and the amount of information is reduced in accordance with the predetermined priority. Processing, silent section deletion processing,
By appropriately performing the time axis compression process, the free space of the recording medium 12 can be increased more effectively.

Further, the priority is set by the time of recording, the contents of the recorded audio source, the user who recorded, the frequency of reproduction after recording, the manual addition of the user to individual files, and the audio. The ratio of the voice section in the signal, the speech rate of the human voice contained in the voice signal,
Etc. are comprehensively taken into consideration when making a decision. In this way, the amount of information required to create a new free space can be effectively extracted from the low priority corresponding to the importance, and the high importance can be generated without deterioration due to compression. The data can be played back.

[0072]

As described above, according to the present invention, even if the recording capacity of the recording medium becomes small, it is possible to efficiently record the input audio signal on the recording medium with little quality deterioration. Further, since the voice data accumulated in the recording medium is automatically re-recorded due to its priority, it is possible to re-edit many voice data according to the intention of the user of the voice recording / reproducing apparatus. In particular, it is most suitable for a recording medium such as a semiconductor memory having a limited recording capacity.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an audio recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an audio recording / reproducing device according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of an audio recording / reproducing apparatus according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of an audio recording / reproducing device according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of an audio recording / reproducing apparatus according to a fifth embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration example of a conventional audio recording / reproducing apparatus.

[Explanation of symbols]

 11 voice recording means 12 recording medium 13 remaining recording amount detection means 14 priority determination control means 15 information source coding means 16 reproducing means 25 high efficiency coding means 35 silent section deleting means 45 time axis compression means 55 information amount reducing means

Claims (30)

[Claims] 1. A recording medium for holding data including audio, an audio recording means for recording an input audio signal on the recording medium, and a reproducing means for reproducing the data recorded on the recording medium and converting the data into an audio signal. A recording remaining amount detecting means for detecting a free space of data of the recording medium, and a control for determining a priority of an audio signal and reducing the information amount of the audio data recorded on the recording medium based on the priority. Reducing the information amount of the audio data already recorded on the recording medium, by using a priority determination control means for controlling and a source coding capable of reversible compression / expansion based on the priority indicated by the priority determination control means. Information source coding means for increasing the free space of the recording medium by re-recording the data in the recording medium. Audio recording and reproducing apparatus according to claim Rukoto. 2. The audio recording / reproducing apparatus according to claim 1, wherein the priority determination control means determines the priority according to the time when the audio signal is recorded. 3. The audio recording / reproducing apparatus according to claim 1, wherein the priority determination control means determines the priority according to the content of the audio source recorded on the recording medium. 4. The audio recording / reproducing apparatus according to claim 1, wherein the priority determination control means determines priority according to a user who has recorded on the recording medium. 5. The audio recording / reproducing apparatus according to claim 1, wherein the priority determination control means determines the priority according to the frequency of reproduction from the recording medium. 6. The voice according to claim 1, wherein the priority determination control means determines priority based on a value given to an individual data file by a user of the recording medium. Recording / playback device. 7. A recording medium for holding data including audio, an audio recording means for recording an input audio signal in the recording medium, and a reproducing means for reproducing the data recorded in the recording medium and converting the data into an audio signal. A recording remaining amount detecting means for detecting a free space of data of the recording medium, and a control for determining a priority of an audio signal and reducing the information amount of the audio data recorded on the recording medium based on the priority. Priority determining control means, and based on the priority indicated by the priority determining control means, the information amount of the audio data already recorded on the recording medium is reduced by using high efficiency encoding, and the data is recorded on the recording medium. And a high-efficiency encoding means for increasing the free space of the recording medium by re-recording to the audio recording medium. Raw devices. 8. The voice recording / reproducing apparatus according to claim 7, wherein the priority determination control means determines the priority according to the time when the voice signal is recorded. 9. The audio recording / reproducing apparatus according to claim 7, wherein the priority determination control means determines the priority according to the content of the audio source recorded on the recording medium. 10. The audio recording / reproducing apparatus according to claim 7, wherein the priority determination control means determines priority according to a user who has recorded on the recording medium. 11. The audio recording / reproducing apparatus according to claim 7, wherein the priority determination control means determines the priority according to the frequency of reproduction from the recording medium. 12. The voice according to claim 7, wherein the priority determination control means determines priority based on a value given to an individual data file by a user of the recording medium. Recording / playback device. 13. A recording medium for holding data including audio, an audio recording means for recording an input audio signal in the recording medium, and a reproducing means for reproducing the data recorded in the recording medium and converting the data into an audio signal. A recording remaining amount detecting means for detecting a free space of data of the recording medium, and a control for determining a priority of an audio signal and reducing the information amount of the audio data recorded on the recording medium based on the priority. Priority determination control means to, based on the priority instructed by the priority determination control means, by deleting an unnecessary silent section of the audio signal, to reduce the information amount of the audio data already recorded on the recording medium, Re-recording the data on the recording medium to increase the free space of the recording medium, and a silent section deleting unit. Audio recording and reproducing apparatus characterized by. 14. The audio recording / reproducing apparatus according to claim 13, wherein the priority determination control means determines the priority according to the time when the audio signal is recorded. 15. The audio recording / reproducing apparatus according to claim 13, wherein the priority determination control means determines the priority according to the content of the audio source recorded in the recording medium. 16. The priority determination control means determines the priority according to the user who has recorded on the recording medium.
The audio recording and reproducing apparatus described. 17. The audio recording / reproducing apparatus according to claim 13, wherein the priority determination control means determines the priority according to the frequency of reproduction from the recording medium. 18. The audio according to claim 13, wherein the priority determination control means determines priority based on a value given to an individual data file by a user of the recording medium. Recording / playback device. 19. The audio recording / reproducing according to claim 13, wherein the priority determination control means determines the priority according to a ratio of a voice section in a voice signal recorded on the recording medium. apparatus. 20. A recording medium for holding data including audio, an audio recording means for recording an input audio signal on the recording medium, and a reproducing means for reproducing the data recorded on the recording medium and converting the data into an audio signal. A recording remaining amount detecting means for detecting a free space of data of the recording medium, and a control for determining a priority of an audio signal and reducing the information amount of the audio data recorded on the recording medium based on the priority. Priority determination control means, and, based on the priority indicated by the priority determination control means, by using time axis compression processing to reduce the recording time length of the audio signal, information of the audio data already recorded on the recording medium. The time axis compression method for reducing the amount and increasing the free space of the recording medium by re-recording the data on the recording medium. If, audio recording and reproducing apparatus characterized by comprising a. 21. The audio recording / reproducing apparatus according to claim 20, wherein the priority determination control means determines the priority according to the time when the audio signal is recorded. 22. The audio recording / reproducing apparatus according to claim 20, wherein the priority determination control means determines the priority according to the content of the audio source recorded in the recording medium. 23. The priority determination control means determines a priority according to a user who has recorded on the recording medium.
The audio recording and reproducing apparatus described. 24. The audio recording / reproducing apparatus according to claim 20, wherein the priority determination control means determines the priority according to the frequency of reproduction from the recording medium. 25. The voice according to claim 20, wherein the priority determination control means determines priority based on a value given to an individual data file by a user of the recording medium. Recording / playback device. 26. The audio recording / reproducing according to claim 20, wherein the priority determination control means determines priority according to a ratio of a voice section in a voice signal recorded on the recording medium. apparatus. 27. The priority determination control means determines the priority according to the utterance speed of a human voice included in the voice signal recorded in the recording medium. Sound recording and reproducing device. 28. A recording medium for holding data including audio, an audio recording means for recording an input audio signal on the recording medium, and a reproducing means for reproducing the data recorded on the recording medium and converting the data into an audio signal. A recording remaining amount detecting means for detecting a free space of data in the recording medium, and a control for determining a priority of an audio signal and reducing the information amount of the audio data recorded in the recording medium based on the priority. Priority determination control means, and based on the priority indicated by the priority determination control means, to reduce the information amount of the audio data already recorded on the recording medium, by re-recording the data in the recording medium An audio recording / reproducing apparatus comprising: an information amount reducing means for increasing a free space of a recording medium. 29. The priority determination control means is characterized in that the time of recording on the recording medium, the classification according to the contents of the audio source, the user who recorded, the frequency of reproduction after recording, the sound in the audio signal. 29. The voice recording / reproducing apparatus according to claim 28, wherein the priority is determined in consideration of two or more of the ratio of the sections and the utterance speed of the human voice included in the voice signal. 30. The information amount reducing means reduces the information amount of a voice signal by using two or more methods of information source coding, high efficiency coding, silent section deletion, and time axis compression. 29. The audio recording / reproducing apparatus according to claim 28.