KR930008775B1 - Recording and reproducing methods and apparatus - Google Patents

Abstract

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Description

Recording and playback method and recording and playback device

1 and 2 are block diagrams showing a basic configuration example of the present invention.

3 is an explanatory diagram illustrating the principle of the present invention.

4 and 5 are block diagrams showing a first embodiment of the present invention.

6 is a block diagram specifically showing a part of the first embodiment;

7 and 8 are block diagrams showing a second embodiment of the present invention.

9 and 10 are block diagrams showing a third embodiment of the present invention.

11 and 12 are explanatory views specifically showing a part of the third embodiment.

13 and 14 are block diagrams showing a fourth embodiment of the present invention.

15 and 16 are block diagrams showing a fifth embodiment of the present invention.

17 and 18 are block diagrams showing a sixth embodiment of the present invention.

FIG. 19 is an explanatory diagram showing the data configuration of the data storage circuit in FIGS. 17 and 18. FIG.

20 is an explanatory diagram for explaining the principle of the sixth embodiment;

* Explanation of symbols for main parts of the drawings

SL1: first selection means TR1: first conversion means

MR1: first storage means SL2: second selection means

TR23: second conversion means MR2: second storage means

SD1: first amplitude level detection means TS1: first conversion range selection means

SD2: first amplitude level detection means TS2: second conversion range selection means

CD1: control data insertion means CDO: control data extraction means

AD1: first A / D conversion means SCM: signal compression means

DA1: first A / D conversion means SEP: signal extension means

AD2: second A / D conversion means ADTL: A / D conversion range changing means

DA2: second D / A conversion means DATL: D / A conversion range changing means

AD3: third A / D conversion means CT1: first gain changing means

CH1: variable input means DA3: third D / A conversion means

GT2: second gain changing means CH0: variable output means

The present invention relates to a recording and reproducing method and a recording and reproducing apparatus.

Background Art Conventionally, a PCM (Pulse coded Modulation) method is known as a method for recording and reproducing sound signals such as voice and melody.

Also, as an improved method of the PCM method, an adaptive differential pulse coded modulation (ADPCM) method is known.

The PCM method has a problem that the amount of information to be stored increases.

In addition, the ADPCM method has a problem in that it is not possible to follow a waveform whose amplitude changes abruptly in order to store difference data between adjacent sound data.

An object of the present invention is to obtain a recording and reproducing method which can attain a minimum amount of information to be stored and can also follow a waveform whose amplitude changes rapidly, and at the same time, to obtain the recording and reproducing apparatus.

In the recording method according to the present invention, the original sound signal is converted into a digital sound signal at a conversion range selected according to the amplitude information of the original sound signal, and the converted digital sound signal is stored and recorded.

The recording apparatus for realizing the recording method comprises: first selecting means for selecting a conversion range according to amplitude information of the original sound signal, and a first conversion means for converting the original sound signal into a digital sound signal at the conversion range selected by the first selection means. And a first storage means for storing the digital sound signal converted by the first conversion means.

The reproduction method according to the present invention reads out the stored digital sound signal, converts the digital signal into an analog sound signal at a conversion range selected according to the amplitude information of the digital sound signal, and plays back.

The reproducing apparatus for realizing the reproducing method comprises second storage means for storing the digital sound signal, and a second conversion means for selecting a conversion range in accordance with the amplitude information of the original sound signal with a wide conversion range when the amplitude of the digital sound signal is increased. And a second converting means for converting the digital sound signal into an analog sound signal in the conversion range selected by the second selecting means and the second selecting means.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated based on drawing.

The principle of the present invention is to convert the original sound signal (waveform shown by the solid line) into the digital sound signal in the conversion range (shown by the broken line) selected according to the amplitude of the original sound signal as shown in FIG. That is, as shown in the diagram, when the amplitude of the original sound signal is large, the original sound signal is converted into a wide conversion range. When the amplitude of the original sound signal is small, the original sound signal is converted into a narrow conversion range. For example, in a certain conversion range, if the digital sound signal is composed of a certain number of bits, recording and reproduction can be performed at the same sound quality without being large or small in amplitude of the original sound signal. An example of the basic configuration of the recording apparatus and the playback apparatus in the present invention will be described with reference to FIGS.

In addition, although the recording apparatus shown in FIG. 1 and the playback apparatus shown in FIG. 2 can be understood as separate things, the sound recorded by the recording apparatus shown in FIG. Will be described as being played back by the playback device shown in FIG.

1 is a block diagram showing an example of the basic configuration of a recording apparatus.

IP is an input means and outputs an original sound signal "a".

In this embodiment, the input means IP is comprised of a microphone, an amplification circuit, etc., and inputs sound, such as a voice, and converts it into an original sound signal. The original sound signal may usually be an analog signal or a digitalized one.

SL1 is a first selection means and selects a conversion range according to the amplitude of the original sound signal " a " output from the input means IP. It is preferable that the width of each conversion range is selected so as to change in proportion. If you express it as a formula,

A = A 0 B ⁿ . … … … … … … … … … … … … … … (One)

here,

A… … … … … … … … … … … … … … … Width of each conversion range

A0…. … … … … … … … … … … … … … Width of the maximum conversion range

B… … … … … … … … … … … … … … … Integer less than 1

n… … … … … … … … … … … … … … … essence

Becomes

For example, in the above formula, B = 1/2, the width of each conversion range is 1/2 × A0, 1/4 × A0 with respect to the width AO of the maximum conversion range, as shown in FIG. ,… Becomes

TR1 is the first conversion means, the conversion range selected by the first selection means SL1, converts the original sound signal "a" into a digital sound signal, and outputs the digital sound signal "b1". Normally, the digital sound signal is composed of a fixed number of bits, and does not change depending on the conversion range.

MR1 is a first storage means and stores the digital sound signal " b1 " output from the first conversion means TR1. This first storage means MR1 is usually constituted by RAM (Randam Access Memory) or the like.

The operation of the recording apparatus shown in FIG. 1 is as follows.

Sound such as voice or melody is input to the input means IP. The sound is detected by the microphone, then amplified by the amplifier circuit, and output as the original sound signal "a".

In the first conversion means TR1, the conversion range selected by the first selection means SL1 converts the original sound signal " a " into digital data of a predetermined number of bits at predetermined time intervals, thereby converting the digital sound signal " b1. Prints " That is, the digital sound signal "b1" converts the original sound signal "a" into sequential digital data. The conversion range at this time is selected by the first selection means SL1. The conversion range information d1 output from the first selecting means SL1 may be information indicating the width of the conversion range, or may be information for up or down the conversion range.

In the present embodiment, however, the conversion range selected by the first selection means SL1 is selected by inputting the digital sound signal " b1 " to the first selection means SL1 as shown in FIG. However, the conversion range can also be selected, for example, by inputting the original sound signal " a " into the first selection means SL1. In short, the signal for selecting the conversion range may be obtained by inputting a signal corresponding to the amplitude information of the original sound signal to the first selecting means SL1.

The digital data of the digital sound signal " b1 " output from the first conversion means TR1 are sequentially stored in the first storage means MR1.

The recording operation is performed as described above.

2 is a block diagram showing an example of the basic configuration of a playback apparatus.

MR2 is a second storage means, and a digital sound signal is stored, and is usually constituted by a ROM (Read Only Memory) or the like. The digital sound signal is usually composed of a fixed number of bits and does not change with the conversion range. Further, it is preferable to use the digital sound signal obtained by the recording apparatus as the digital sound signal stored in the second storage means MR2.

Sl2 is a second selection means and selects a conversion range in accordance with the amplitude information of the digital sound signal " b2 " output from the second storage means MR2. Preferably, the width of each conversion range is selected corresponding to the first selection means SL1 in the recording apparatus. That is, it is preferable that the width of each conversion range is selected so as to be converted at an equal ratio.

TR2 is the second conversion means, the conversion range selected by the second selection means SL2, and converts the digital sound signal "b2" into an analog sound signal "c".

OP is an output means and inputs the analog sound signal "c". In the present embodiment, the output means OP is composed of an amplifying circuit, a speaker, or the like, and is converted into sound output by inputting the analog sound signal "c". The operation of the playback apparatus shown in FIG. 2 is as follows.

The digital data of the digital sound signal " b2 " output from the second storage means MR2 are sequentially input to the second conversion means TR2, and are not known as the conversion ranges selected by the second selection means SL2. The log tone signal "c" is converted. The conversion range information d2 output from the second selecting means SL2 may be information indicating the width of the conversion range, or may be information for up or down the conversion range.

In the present embodiment, however, the conversion range selected by the second selection means SL2 is selected by inputting the digital sound signal " b2 " to the second selection means SL2, as shown in FIG. However, the conversion range may be selected by inputting, for example, the analog sound signal "c" to the second selection means SL2. In short, a signal corresponding to the amplitude information of the digital sound signal may be input to the second selection means SL2 for selection.

The analog sound signal "c" output from the second conversion means TR2 is input to the output means OP, amplified by the amplifying circuit, and then output as sound from the speaker.

The reproducing operation is performed as described above.

In the above-described basic configuration example, in the recording, the original sound signal is converted into the digital sound signal at the conversion range selected according to the amplitude, and in reproduction, the digital sound signal is converted into the analog sound signal in the conversion range selected according to the amplitude of the digital sound signal. By converting to, the recording and reproducing apparatus can be obtained which can keep track of a waveform whose amplitude changes rapidly while decreasing the amount of information to be stored.

Next, an embodiment in which each component of the recording apparatus and playback apparatus described in "Basic Configuration Example" is shown as a specific example will be described below.

Incidentally, the points not specifically described in the following embodiments are the same as the above "basic configuration examples".

Example 1

A first embodiment based on the recording apparatus and playback apparatus described in "Basic Configuration Example" will be described with reference to FIGS. 4 and 5. FIG.

In addition, although the recording apparatus shown in FIG. 4 and the playback apparatus shown in FIG. 5 can be seen as separate things, the sound recorded by the recording apparatus shown in FIG. Is reproduced by the playback apparatus shown in FIG.

4 is a block diagram showing the recording apparatus in the first embodiment.

The input means IP, the first storage means MR1, and the first conversion means TR1 are the same as those described in the "Basic Configuration Example".

The first selection means SL1 comprises a first amplitude level detecting means SD1 and a first conversion range selecting means TS1.

The first amplitude level detecting means SD1 detects the amplitude level according to the amplitude information of the original sound signal " a " output from the input means IP. In this embodiment, as shown in FIG. 4, the digital sound signal "b1" is input to the first amplitude level detecting means SD1. However, the signal input to the first amplitude level detecting means SD1 may be a signal corresponding to the amplitude information of the original sound signal.

The first conversion range selecting means TS1 receives the information of the amplitude level detected by the first amplitude level detecting means SD1 and selects the most suitable conversion range.

The operation of the recording apparatus shown in FIG. 4 is as follows.

The original sound signal "a" is input to the first conversion means TR1, is a conversion range selected by the first conversion range selecting means TS1, and is sequentially converted into digital data of the digital sound signal "b1".

Each digital data in the digital sound signal " b1 " is stored in the first storage means MR1 and is sequentially input to the first amplitude level detecting means SD1, and the amplitude level is detected for each digital data. .

Each amplitude level information detected for each digital data of the digital sound signal " b1 " is sequentially input to the first conversion range selecting means TS1, and is based on each successive amplitude level information (e.g., information for 128 bytes). The optimum conversion range is selected.

The recording operation is performed as described above.

5 is a block diagram showing a playback apparatus in the first embodiment.

The output means OP, the second storage means MR2 and the second conversion means TR2 are the same as those described in the above "basic configuration example".

The second selecting means SL2 is constituted from the second amplitude level detecting means SD2 and the second converting range selecting means TS2.

The second amplitude level detecting means SD2 detects an amplitude level corresponding to the amplitude information of the digital sound signal " b2 " output from the second storage means MR2.

In this embodiment, as shown in FIG. 5, the digital sound signal "b2" is input to the second amplitude level detecting means SD2. However, the signal input to the second amplitude level detecting means SD2 may be a signal corresponding to the amplitude information of the digital sound signal.

The second conversion range selecting means TS2 receives information of the amplitude level detected by the second amplitude level detecting means SD2 and selects the most suitable conversion range.

The operation of the playback apparatus shown in FIG. 5 is as follows.

The digital data of the digital sound signal " b2 " output from the second storage means MR2 are input to the second conversion means TR2, and are sequentially input to the second amplitude level detection means SD2, An amplitude level is detected for each digital data.

Each amplitude level information detected for each digital data of the digital sound signal " b2 " is sequentially input to the second conversion range selecting means TS2, and is based on each successive amplitude level information (e.g., information for 128 bytes). The most appropriate conversion range is selected.

In the second conversion means, the digital sound signal "b2" is converted into the analog sound signal "c" in the conversion range selected by the second conversion range selection means TS2.

The reproducing operation is performed as described above.

Here, specific examples of the first conversion range selecting means TS1, the second conversion range selecting means TS2, the first amplitude level detecting means SD1, and the second amplitude level detecting means SD2; The operation will be described.

The first conversion range selecting means TS1 and the second conversion range selecting means TS2 can have the same configuration, and the first amplitude level detecting means SD1 and the second amplitude level detecting means. (SD2) can also have the same configuration. The configuration thereof is as shown in FIG. 6.

Digital data b1 and b2 of the digital sound signal are sequentially input to the comparator 11 from the first conversion means TR1 and the second conversion means TR2 shown in FIGS. 4 and 5. . In the comparator 11, the value of the amplitude level included in the digital sound signals b1 and b2 is the maximum value 111... 1 in the conversion range selected at that time and the maximum value in the 1/2 conversion range. It is judged whether or not it is larger than (011… 1). When larger than the former value, "1" is output to the terminal P1 and larger than the latter value to the terminal P2.

Each time the terminals P1 and P2 of the comparator 11 become " 1 ", the counter 12 is counted up independently by the respective outputs of the terminals P1 and P2. Each time one data is input to the comparator 11, the counter 13 (128 binary) is counted up.

When the count value of the counter 13 becomes "128", the first count value giving the number of outputs larger than the maximum value 111 ... 1 in the conversion range selected at that time, and the 1/2 The second count value giving the number of outputs larger than the maximum value (011 ... 1) in the conversion range of? Is output from the counter 12, respectively. In the comparator 14, the count value is compared with the first reference value ("3") and the second reference value ("3"), respectively. When the first count value of the counter 12 is equal to or greater than the first reference value "3", the conversion range of the conversion range specifying register 16 is increased by one step, and the second count value of the counter 12 is set to the second value. When the reference value is "3" or less, the conversion range of the conversion range designation register 16 is down by one step. As a result, the most appropriate conversion range information d1 and d2 are output from the conversion range designation register 16.

Then, the data of the counter 12 is cleared through the delay circuit 15 by the output of the counter 13 after completion of the comparison operation to the comparator 14.

The recording apparatus and the playback apparatus in this embodiment can automatically select the conversion range by the first conversion range selecting means TS1 and the second conversion range selecting means TS2. In addition, since the conversion range can be selected automatically, it is not necessary to store the conversion range information in the first storage means MR1 and the second storage means MR2, so that the storage capacity can be reduced.

Example 2

A second embodiment based on the recording apparatus and playback apparatus described in "Basic Configuration Example" will be described with reference to FIG. 7 and FIG. In addition, although the recording apparatus shown in FIG. 7 and the playback apparatus shown in FIG. 8 can be understood as separate things, the sound recorded by the recording apparatus shown in FIG. Will be described by the playback apparatus shown in FIG.

Fig. 7 is a block diagram showing the recording apparatus in the second embodiment. The input means IP, the first storage means MR1, and the first conversion means TR1 are the same as those described in the "Basic Configuration Example".

The first selecting means SL1 comprises a third amplitude level detecting means SD3, a third converting range selecting means TR3, and a control data inserting means CD1.

The third amplitude level detecting means SD3 and the third converting range selecting means TR3 are the first amplitude level detecting means SD1 and the first converting range selecting means TR1 described in the first embodiment. Is the same thing as

The control data insertion means CD1 inserts the conversion range information selected by the third conversion range selection means TS3 into the digital data of the digital sound signal " b1 " output from the first conversion means TR1. .

The operation of the recording apparatus shown in FIG. 7 is as follows.

The original sound signal "a" is input to the first conversion means TR1 and sequentially converted into digital data of the digital sound signal "b1" in the conversion range selected by the third conversion range selection means TS3.

The digital data in the digital sound signal " b1 " are input to the control data insertion means CDI, and are sequentially input to the third amplitude level detection means SD3, and the amplitude level is detected for each digital data.

In the third conversion range selecting means TS3, the same operation as that described with reference to Fig. 6 in the " Embodiment 1 " is performed, and the conversion range is selected.

In the control data insertion means CDI, any one of the jumps of (1) to (3) shown below is performed. (1) Conversion range information is inserted for each digital data in the digital sound signal "b1". (2) Conversion range information is inserted for each predetermined number of digital data in the digital sound signal " b1 ". For example, 1 byte of conversion range information is inserted for every 128 bytes of digital data in the digital sound signal "b1". (3) Whenever the conversion range changes, the conversion range information is inserted.

Incidentally, in the above (1) to (3), the data to be inserted may be the conversion range itself, or may be information to up or down the conversion range.

The conversion range information output from the control data insertion means CDI is output together with the digital sound signal and stored in the first storage means MR1.

The recording operation is performed as described above.

8 is a block diagram showing a playback apparatus in the second embodiment.

The output means OP, the second storage means MR2 and the second conversion means TR2 are the same as those described in the above "basic configuration example".

The second selection means SL2 is constituted by the control data extraction means CDO and the fourth conversion range selection means TS4.

The control data extraction means CDO extracts the conversion range information output together with the digital sound signal from the second storage means MR2.

The fourth conversion range selecting means TS4 selects the conversion range on the basis of the conversion range information extracted from the control data extraction means CDO.

The operation of the playback apparatus shown in FIG. 8 is as follows.

The conversion range information is output from the second storage means MR2 together with the digital sound signal. The conversion range information is extracted by the control data extraction means CDO and sent to the fourth conversion range selection means TS4.

On the other hand, the digital sound signal is sent to the second conversion means TR2, and is converted into the analog sound signal " c " in the conversion range selected by the fourth conversion range selection means TS4.

The second storage means MR2 stores data stored in the first storage means MR1 shown in FIG. Therefore, the data inserted into the control data insertion means CDI shown in FIG. 7 is extracted from the control data extraction means CDO.

In the fourth conversion range selecting means TS4, the conversion range is selected based on the conversion range information extracted by the control data extraction means CDO.

The reproducing operation is performed as described above.

The recording apparatus and playback apparatus in this embodiment can store the conversion range information separately from the digital sound signal by providing the control data inserting means (CDI) and the control data extracting means (CDO). Therefore, in particular, the configuration of the playback apparatus can be simplified.

Example 3

A third embodiment based on the recording apparatus and playback apparatus described in "Basic Configuration Example" will be described with reference to FIGS. 9 and 10. FIG.

Incidentally, the recording apparatus shown in FIG. 9 and the playback apparatus shown in FIG. 10 can be regarded as separate ones. In the following description, unless otherwise stated, the sound recorded by the recording apparatus shown in FIG. 9 is reproduced by the playback apparatus shown in FIG.

9 is a block diagram showing a recording apparatus according to the third embodiment.

The input means IP, the first storage means MR1 and the first selection means SL1 are the same as those described in the "Basic Configuration Example".

The first conversion means TR1 is constituted by the first A / D conversion means AD1 and the signal compression means SCM.

The first A / D conversion means AD1 converts the original sound signal " a " of the analog input from the input means IP to A / D conversion.

The signal compression means SCM converts the A / D conversion signal "f1" obtained by the first A / D conversion means AD1 into the conversion range selected by the first selection means SL1, and the A / D conversion signal "f1". The digital sound signal " b1 " is obtained by converting the compressed signal to a bit number smaller than the number of bits.

The operation of the recording apparatus shown in FIG. 9 is as follows. The analog original sound signal "a" is subjected to A / D conversion by the first A / D conversion means AD1, whereby the A / D conversion signal "f1" is obtained. The number of bits of the A / D conversion signal "f1" may be selected as appropriate, but it is assumed that the bit is composed of 11 bits (but 1 bit is a sign bit). In the signal compression means SCM, the A / D conversion signal "f1" is a conversion range selected by the first selection means SL1, and a compressed signal having a bit number smaller than the number of bits of the A / D conversion signal "f1" (here 5 bits, and 1 bit is a sign bit). As a result, the digital sound signal "b1" is output from the signal compression means SCM. The digital sound signal " b1 " is stored in the first storage means MR1 and input to the first selection means SL1, and the conversion range information is output from the first selection means SL1.

The recording operation is performed as described above.

Here, the specific example of the signal compression means SCM and its operation is demonstrated using FIG.

In the example shown in FIG. 11, as shown in FIG. 3, the width of each conversion range is 1/2 × A0, 1/4 × A0,... With respect to the width A0 of the maximum conversion range. … I did it.

First, the principle will be described.

For example, in the case of changing from the conversion range A0 to 1/2 × A0, the binary value of “111” in the former conversion range can be represented by a binary value of “1110” in the latter conversion range. This corresponds to one bit shift of data. In other words, when the conversion range is 1/2, the data represented by the binary code is shifted by one bit. Similarly, when the conversion range is set to 1/4, the data represented by the binary code is shifted by two bits. 11B shows a case where the conversion range is 1/8 of the maximum conversion range, and the data is shifted three bits.

The example of FIG. 11 is demonstrated with reference to what was demonstrated above.

FIG. 11A shows the signal compression means SCM in FIG. The conversion range information "d1" is sent to the shift control circuit 31 from the first selection means SL1 in FIG. The conversion range information " d1 " may be information indicating the width of the conversion range or information for up or down the conversion range. Shift data is output from the shift control circuit 31 based on the conversion range information " d1 ".

In the shift circuit 32, the A / D conversion signal " f1 " of 11 bits (however, one bit is a sign bit and the other is an absolute value bit) based on the shift data output from the shift control circuit 31. The absolute value bits other than the sign bit are shifted by a predetermined bit to output a 4-bit absolute value signal. The code detection circuit 33 also receives the A / D conversion signal "f1" and outputs a code bit. The maximum value setting circuit 34 sets the absolute value signal to the maximum value when data is overflowed over the conversion range. In the compressed data forming means, a sign bit (1 bit) and an absolute value bit as shown in Fig. 11C based on data obtained from the shift circuit 32, the code detection circuit 33, and the maximum value setting circuit 34. A compressed signal of four bits is formed to output a digital sound signal b1.

10 is a block diagram showing a playback apparatus in the third embodiment.

The output means OP, the second storage means MR2 and the second selection means SL2 are the same as those described in the above "basic configuration example".

The second converting means TR2 is composed of the first D / A converting means DA1 and the signal extending means SEP. The signal extension means SEP is a conversion range selected by the second selection means SL2, which converts the digital sound signal " b2 " into an extension signal " f2 " of more bits than the number of bits of the digital sound signal " b2 ". will be.

The first D / A conversion means DA1 performs D / A conversion of the extension signal " f2 " output from the signal extension means SEP.

The operation of the playback apparatus shown in FIG. 10 is as follows.

The digital sound signal "b2" (here, 5 bits and 1 bit is a sign bit) is input to the second selecting means SL2 and to the signal extending means SEP. The signal extension means SEP converts the digital sound signal " b2 " into an extension signal " f2 " of 11 bits (but one bit is a sign bit) in the conversion range selected by the second selection means SL2.

The first D / A converting means DA1 performs a D / A conversion of the extension signal "f2" and outputs the analog sound signal "c".

As described above, the reproducing operation is performed.

Here, the specific example of the signal extension means SEP and its operation | movement is demonstrated using FIG.

In the example shown in FIG. 12, the width of each conversion range is 1/2 × Amx. 1/4 x Amx,... … It is done.

The basic operation principle of the signal extension means SEP is the reverse of the operation of the signal compression means SCM described in FIG. 11, and the principle is as described above.

12A shows the signal expansion means SEP in FIG. The digital separation signal " b2 " consisting of a sign bit (1 bit) and an absolute value bit (4 bits) is input to the data separating means 45. The digital sound signal " b2 " input to the data separating means 45 is separated into a sign bit and an absolute value bit (absolute value signal).

The conversion range information "d2" is sent to the shift control circuit 41 from the second selection means SL2 in FIG. The conversion range information " d2 " may be information indicating the width of the conversion range or information for up or down the conversion range. The shift data is output from the shift control circuit 41 based on the conversion range information " d2 ". In the shift circuit 42, four bits shift the absolute value signal by a predetermined bit as shown in FIG. 12B based on the shift data output from the shift control circuit 41, and the 10-bit D / A conversion signal is converted into a shift signal. Output At this time, bits other than 4 bits in which the absolute value signal is shifted become "0". In the data combining means 44, 10 bits combines the 11-bit signal shown in FIG. 12C from the D / A conversion signal and the 1-bit code signal output from the code detecting means 43, and in FIG. The data is sent to the first D / A converting means DA1.

The recording apparatus and the reproduction apparatus in this embodiment are provided with signal compression means SCM and signal expansion means SEP, so that the amount of information to be stored can be reduced.

Specifically, the width of each conversion range is 1/2 × Amx. 1/4 x Amx,... … In this way, the signal compression means SCM and the signal expansion means SEP can be easily configured, and the whole structure is simplified.

Example 4

A fourth embodiment based on the recording apparatus and playback apparatus described in the above "basic configuration example" will be described with reference to FIG. 13 and FIG.

In addition, although the recording apparatus shown in FIG. 13 and the playback apparatus shown in FIG. 14 can be understood as separate things, the sound recorded by the recording apparatus shown in FIG. Is reproduced by the playback apparatus shown in FIG.

Fig. 13 is a block diagram showing a recording apparatus in the fourth embodiment. The input means IP, the first storage means MR1 and the first selection means SL1 are the same as those described in the "Basic Configuration Example".

The first converting means TR1 is composed of the second A / D converting means AD2 and the A / D converting range changing means ADTL.

The second A / D converting means AD2 performs A / D conversion on the analog original sound signal "a" and outputs the digital sound signal "b1".

In this embodiment, the digital sound signal " b1 " is composed of 5 bits (but 1 bit is a sign bit). The A / D conversion range changing means ADTL changes the maximum input range of the second A / D conversion means AD2 corresponding to the conversion range selected by the first selection means SL1.

The operation of the recording apparatus shown in FIG. 13 is to change the maximum input range of the second A / D conversion means AD2 in accordance with the magnitude of the amplitude of the original sound signal "a". For example, when the amplitude of the original sound signal "a" is large, the maximum input range may be widened, and when the amplitude of the original sound signal "a" is small, the maximum input range may be narrowed. Specifically, it is as follows.

The conversion range is selected by the first selection means SL1 based on the digital sound signal " b1 " corresponding to the magnitude of the amplitude of the original sound signal " a. &Quot; The A / D conversion range changing means ADTL changes the maximum input range of the second A / D conversion means AD2 in accordance with the conversion range. The maximum input range of the second A / D conversion means AD2 can be changed, for example, by changing the reference voltage of the A / D conversion.

The second A / D conversion means AD2 performs A / D conversion on the original sound signal "a" in the selected maximum input range to obtain a digital sound signal "b1".

As described above, the recording operation is performed.

14 is a block diagram showing a playback apparatus in the fourth embodiment.

The output means OP, the second storage means MR2, and the second selection means SL2 are the same as those described in the "basic configuration example".

The second converting means TR2 is composed of the second D / A converting means DA2 and the D / A converting range changing means DATL.

The second D / A conversion means DA2 performs D / A conversion of the digital sound signal "b2" and outputs the analog sound signal "c".

In this embodiment, the digital sound signal " b2 " is composed of 5 bits (however, 1 bit is a sign bit). The D / A conversion range changing means DATL is to switch the maximum output range of the second D / A conversion means DA2 corresponding to the conversion range selected by the second selection means SL2.

The operation of the playback apparatus shown in FIG. 14 widens the maximum output range of the second D / A converting means DA2 in accordance with the amplitude of the sound signal determined from the digital sound signal "b2", and when the amplitude is small. You can narrow the maximum output range. Specifically, it is as follows.

The conversion range is selected by the second selection means SL2 based on the amplitude information (the magnitude of the amplitude of the sound signal) of the digital sound signal "b2". The D / A conversion range changing means DATL changes the maximum output range of the second D / A conversion means DA2 in accordance with the conversion range.

The maximum output range of the second D / A conversion means DA2 can be changed, for example, by changing the reference voltage of the D / A conversion.

The second D / A converting means DA2 performs D / A conversion of the digital sound signal "b2" in the selected maximum output range and outputs the analog sound signal "c".

In the present embodiment, the recording apparatus and the playback apparatus use the second A / D conversion range changing means ADTL and the second D / A conversion range changing means DATL. Since the maximum input range of AD2) and the maximum output range of the second D / A converting means DA2 are optimally set according to the amplitude of the sound signal, the amount of information to be stored can be recorded and reproduced at least with high quality.

Example 5

A fifth embodiment based on the recording apparatus and playback apparatus described in the above "basic configuration example" will be described with reference to FIGS. 15 and 16. FIG.

Incidentally, the recording apparatus shown in FIG. 15 and the playback apparatus shown in FIG. 16 can be regarded as separate ones. However, unless otherwise specified in the following description, the recording apparatus shown in FIG. The sound is reproduced by the playback apparatus shown in FIG.

FIG. 15 is a block diagram showing a recording apparatus in the fifth embodiment.

The input means IP, the first storage means MR1 and the first selection means SL1 are the same as those described in the "Basic Configuration Example".

The first conversion means TR1 is constituted by the third A / D conversion means AD3, the variable input means CHI, and the first gain changing means GT1.

The variable input means CHI obtains an amplified signal obtained by amplifying the analog original sound signal "a" and is constituted by an amplifying circuit or the like. The variable input means CHI may attenuate the original sound signal "a", or may amplify and attenuate it.

The third A / D converting means AD3 outputs the digital sound signal " b1 " by A / D converting the amplified signal obtained by the variable input means CHI.

In this embodiment, the digital sound signal " b1 " is composed of 5 bits (but 1 bit is a sign bit).

The first gain changing means GT1 changes the gain of the variable input means CHI corresponding to the conversion range selected by the first selecting means SL1.

The operation of the recording apparatus shown in Fig. 15 is to change the gain (amplitude) of the variable input means CHI in accordance with the magnitude of the amplitude of the original sound signal " a ". For example, the gain may be reduced when the amplitude of the original sound signal "a" is large, and the gain may be increased when the amplitude of the original sound signal "a" is small. Specifically, it is as follows.

The conversion range is selected by the first selection means SL1 based on the digital signal " b1 " corresponding to the magnitude of the amplitude of the original sound signal " a. &Quot;

In the first gain changing means GT1, the gain of the variable input means CHI is changed in accordance with the conversion range. The variable input means CHI amplifies the original sound signal "a" with the selected gain.

In the third A / D conversion means AD3, the amplified signal obtained by the variable input means CHI is subjected to A / D conversion to output a digital sound signal " b1 " of 5 bits (but 1 bit is a sign bit). .

The recording operation is performed as described above.

16 is a block diagram showing a playback apparatus in the fifth embodiment. The output means OP, the second storage means MR2, and the second selection means SL2 are the same as those described in the above "basic configuration example".

The second converting means TR2 is composed of a third D / A converting means DA3, a variable output means CHO and a second gain changing means GT2.

The third D / A conversion means DA3 performs D / A conversion on the digital sound signal "b2" and outputs a D / A conversion signal.

In this embodiment, the digital sound signal " b1 " is composed of 5 bits (but 1 bit is a sign bit).

The variable output means CHO amplifies the D / A converted signal obtained by the third D / A converting means DA3, and is configured by an amplifier circuit or the like. The variable output means CHO may attenuate the D / A converted signal or may amplify and attenuate it.

The second gain changing means GT2 changes the gain of the variable output means CHO in response to the conversion range selected by the second selecting means SL2.

The operation of the recording apparatus shown in Fig. 16 is to change the gain (amplitude) of the variable output means CHO in accordance with the magnitude of the amplitude of the sound signal determined from the digital sound signal "b2".

For example, the gain may be increased when the amplitude of the sound signal determined from the digital sound signal "b" is large, and the gain may be decreased when the amplitude is small. Specifically, it is as follows.

In the third D / A converting means DA, the digital sound signal " b2 " of 5 bits (but 1 bit is a code bit) is subjected to D / A conversion to output a D / A converted signal.

On the other hand, in the second selection means SL2, the conversion range is selected by the second selection means SL2 based on the amplitude information (the magnitude of the amplitude of the sound signal) of the digital sound signal "b2".

In the second gain changing means GT2, the gain of the variable output means CHO is changed in accordance with the selected conversion range. The variable output means CHO amplifies the D / A converted signal with the selected gain. The recording operation is performed as described above.

In the recording apparatus and the reproduction apparatus in this embodiment, the gain of the variable input means CHI and the gain of the variable output means CHO are obtained by the first gain changing means GT1 and the second gain changing means GT2. Can be optimally set according to the amplitude of the sound signal, so that the amount of information to be stored can be recorded and played back at least in high quality.

Example 6

Next, specific examples of the recording apparatus and playback apparatus described in the "Example 3" will be described using FIGS. 17 and 18 as the sixth embodiment.

This embodiment relates to a specific example of the signal compression means SCM shown in FIG. 9 and the signal extension means SEP shown in FIG.

First, the principle is demonstrated before demonstrating a specific structure. When the widths of the respective conversion ranges are selected in an exponential order, as described above, they are displayed as follows.

A = A 0 B ⁿ . … … … … … … … … … … … … … … (One)

but,

A =…. … … … … … … … … … … … … … … Width of each conversion range

A0…. … … … … … … … … … … … … … … Width of the maximum conversion range

B… … … … … … … … … … … … … … … essence

Here, each constant of Formula (1) is expressed as follows.

B = (1/2) ^{1 / k} ... … … … … … … … … … … … … … … (2)

n = 4i + j... … … … … … … … … … … … … … … (3)

but,

k… … … … … … … … … … … … … … … Integer greater than 1

j… … … … … … … … 0,1,2... … … … … … …

j… … … … … … … … 0,1,2... … … … … … … , k-1

As a result, the expression (1) is as follows.

A = AO · [(1/2) ^{1 / k} ] ( ^{4i + j} ). … … … … … … … … … … … … … … (4)

In the formula (4), k = 4 is as follows.

A = AO · ((1/2) ^{1 / k} ] ( ^{4i + j} )

= AO · [(1/2) ¹ ] (1/2) ^{j / 4} ). … … … … … … … … … … … … … … (5)

but,

i =… … … … … … … 0,1,2... … … … … … … …

j = 0,1,2,3

Therefore, when the relationship of equation (5) is shown, it is like 20th degree. Here, for example, when j = 0, it turns out that the value of "A" is 1/2 every time the value of "i" increases by one. The same is true for j = 1,2,3. That is, the width (the value of "A") of the conversion range is reduced to 1/2 every four ranges. As described above, when the conversion range is 1/2, each binary data may be shifted by one bit.

The example of FIG. 17 and FIG. 18 is demonstrated with reference to what was demonstrated above. FIG. 17 shows the signal compression means SCM in FIG. In the circuit shown in the present example, the data " f1 " of 11 bits (where 1 bit is a sign bit) output from the first / D conversion means ADI in Fig. 9 is finally 5 bits (but 1 The bit is compressed into data " b1 " of code bit) and sent to the first storage means MR1 in FIG.

The conversion range information "d1" is input to the range designation circuit 51 from the 1st selection means SL1 in FIG. The conversion range information " d1 " may be information indicating the width of the conversion range or information for up or down the conversion range. From the range designation circuit 51, conversion range designation information of 2 bits and 3 bits is sent to the data storage circuit 56 and the shift circuit 52, which will be described later.

The clock signal " g " is input to the counter circuit 57, and counts up sequentially. This counter circuit 57 is a hexadecimal counter, and a 4-bit count value is sent to the data storage circuit 56 described later every time the count value is counted up.

The data storage circuit 56 is composed of a ROM (lead only memory), the upper two bits of the address are designated by the range designation circuit 51, and the lower four bits are designated by the counter circuit 57. The data structure in the data storage circuit 56 is as shown in the 19th diagram, and each data is divided into four blocks corresponding to the conversion range. Address "63", "62",... … … , "48" includes binary data "111000000", "1110000000",... … … "0000000000" is stored. That is, the lower four bits of the address and the upper four bits of the binary data are all the same.

In the addresses "47" through "32", the data "960" through "0" stored in the addresses "63" through "48" are multiplied by "(1/2) ^1/4 ", respectively.

In the addresses "31" to "16", the data "960" to "0" stored in the addresses "63" to "48" are multiplied by "(1/2) ^1/4" respectively. In the addresses "15" to "0", the data "960" to "0" stored in the addresses "63" to "48" are multiplied by "(1/2) ^1/4" respectively.

10-bit data from the data storage circuit 56 is input to the shift circuit 52. This 10-bit data is data stored at an address designated by the range designation circuit 51 and the counter circuit 57. The 10-bit data input to the shift circuit 52 is shifted by a predetermined number of bits by the 3-bit range designation information sent from the range designation circuit 51.

In the code detection circuit 53, the code bits are included in the A / D conversion data " f1 " of 11 bits (where 1 bit is a code bit) output from the first A / D conversion means AD1 in FIG. Is extracted.

In the coincidence detection circuit 58 each time the counter circuit 57 counts up with the clock signal " g ". The shift data (10 bits) output from the shift circuit 52 is compared with the absolute value data (10 bits) in the A / D conversion data " f1 ".

The absolute value data can in principle take a value equal to 2 ¹⁰ , but the shift data output from the shift circuit 52 only takes a limited value corresponding to the binary data shown in FIG. 19.

Therefore, in practice, it is assumed that both data coincide with each shift data when the absolute value data is within a certain range.

For example, if any absolute value data Dx is input to the coincidence detection circuit 58, the shift data below and below the absolute value data Dx and closest to the absolute value data Dx is the same. When entered in, both data are considered to match.

If both data match, the gate circuit 59 is opened, and the count value at that time of the counter circuit 57 is input to the data forming circuit 55 described later. Therefore, the count value at the time when both data coincide is the absolute value data compressed to 4 bits. In other words, when the two data coincide with each other, the lower four bits of the designated address for the data storage circuit 56 become the 4-bit absolute value data.

In the data forming circuit 55, compressed data " b1 " of 5 bits (4 bits are absolute value data and 1 bit is code data) is formed on the basis of each of the above data, and the first shown in FIG. Is sent to the memory means MR1.

FIG. 18 shows the signal extending means SEP in FIG. In the circuit shown in this example, the data " b2 " of 5 bits (but 1 bit is a sign bit) output from the second storage means MR2 in FIG. Code bit) to be extended to the data " f2 " and sent to the first D / A conversion means DA1 in FIG. The data stored in the second storage means MR2 shown in FIG. 10 is stored in the second storage means MR2 shown in FIG. 9, and the data stored in the second storage means MR2 shown in FIG. This is the same as the data stored in the memory circuit MR1.

In the data separation circuit 65, 5-bit compressed data 'b2' sent from the second storage means MR2 shown in FIG. 10 is separated into 4-bit absolute value data and 1-bit code data.

The conversion range information "d2" is input to the range designation circuit 61 from the second selection means SL2 in FIG. The conversion range information " d2 " may be information indicating the width of the conversion range or information for up or down the conversion range. The range designation circuit 61 sends conversion range designation information of 2 bits and 3 bits to the data storage circuit 66 and the shift circuit 62, respectively.

The data storage circuit 66 is composed of a ROM (lead only memory), the upper two bits of the address are designated by the range designating circuit 61, and the lower four bits are designated by the data separating circuit 65. It is designated by the data separation circuit 65. The data structure of the data storage circuit 66 is the same as that of the data storage circuit 56 in FIG.

10-bit data is input to the shift circuit 62 from the data storage circuit 66. The 10-bit data input to the shift circuit 62 is shifted by a predetermined number of bits by the 3-bit range designation information sent from the range designation circuit 61.

In the data combining circuit 62, 11 bits of decompression data " f2 " are formed from 10 bits of absolute value data output from the shift circuit and 1 bit of code data output from the data separation circuit. It sends out to the D / A conversion means DA1 of 1.

As mentioned above, although the basic structural example and each Example were demonstrated, each component can be shared by the reproduction apparatus of a recording apparatus in the basic structural example and each Example. Therefore, by appropriately sharing the components, it is also possible to easily configure a recording / playback apparatus that also serves as a recording apparatus and a playback apparatus.

Needless to say, the principles, devices, and the like described in the embodiments can be appropriately combined.

According to the present invention, when recording, the original sound signal is converted into a digital sound signal at a conversion range selected according to the amplitude of the original sound signal, and during reproduction, the digital sound signal is converted to a conversion range selected according to the amplitude of the digital sound signal. By converting into a signal, a recording and reproducing apparatus capable of following a waveform whose amplitude changes rapidly while reducing the amount of information to be stored can be obtained.

In the recording apparatus and playback apparatus provided with the conversion range selecting means, the conversion range can be automatically selected.

In addition, since the conversion range can be selected automatically, it is not necessary to store the conversion range information in the storage means, so that the storage capacity can be reduced.

In the recording and reproducing apparatus provided with the control data inserting means and the control data extracting means, the conversion range information can be stored separately from the digital sound signal. Therefore, in particular, the configuration of the playback apparatus can be simplified.

In the recording apparatus and playback apparatus provided with the signal compression means and the signal expansion means, the amount of information to be stored can be reduced. In particular, the width of each conversion range is 1/2, 1/4,... Relative to the width of the maximum conversion range. … In this case, the signal compression means and the signal extension means can be easily configured, and the overall configuration is simplified.

In the recording and reproducing apparatus provided with the A / D conversion range changing means and the D / A conversion range changing means, the maximum input range of the A / D conversion means and the maximum output range of the D / A conversion means are set according to the amplitude of the sound signal. Because it is set most appropriately, it can record and play back with high quality even if the amount of information to be stored is small.

In the recording apparatus and the reproduction apparatus provided with the gain changing means, the gains of the variable input means and the variable output means are set most appropriately according to the amplitude of the sound signal, so that the amount of information to be stored can be recorded and reproduced at least with high quality.

Claims (10)

First amplitude level detection means for detecting an amplitude level in accordance with amplitude information of the original sound signal and sequentially outputting a digital amplitude signal in accordance with the original sound signal, and first conversion range selecting means for selecting a conversion range based on the digital amplitude signal Recording means comprising: first conversion means for converting an original sound signal into a digital sound signal at a conversion range selected by said first conversion range selecting means, and first storage means for storing said digital sound signal converted into said first conversion range; In the apparatus, the first conversion range selecting means comprises: a comparator for generating a range over signal when the digital amplitude signal is greater than the maximum value of the currently selected conversion range, and a predetermined number of times the range over signal occurs within a predetermined period. Specially comprising a conversion range designation circuit which raises the conversion range by one step. Recording device. First amplitude level detection means for detecting an amplitude level according to amplitude information of the original sound signal and sequentially outputting a digital amplitude signal according to the original sound signal, first conversion range selecting means for selecting a conversion range based on the digital amplitude signal; A recording device comprising first conversion means for converting an original sound signal into a digital sound signal at a conversion range selected by said first conversion range selecting means, and first storage means for storing said digital sound signal converted by said first conversion means; And the first conversion range selecting means comprises: a comparator for generating a range over signal when the digital amplitude signal is greater than a maximum value of the conversion range under one step of the currently selected conversion range, and the range over signal being generated within a predetermined period. Conversion range designating circuit for lowering the conversion range by one step when the number of times is less than the predetermined number Recording device, characterized in that consisting of. First amplitude level detection means for detecting an amplitude level according to amplitude information of the original sound signal and sequentially outputting a digital amplitude signal according to the original sound signal, first conversion range selecting means for selecting a conversion range based on the digital amplitude signal, And a first converting means for converting the original sound signal into a digital sound signal in the conversion range selected by the first converting range selecting means, and a first storage means for storing the digital sound signal converted into the first converting means. And the first conversion range selecting means generates a first range over signal when the digital amplitude signal is greater than the maximum value of the currently selected conversion range, and converts the first conversion range under one step of the currently selected conversion range. A comparator for generating a first range over signal when the range is greater than a maximum value of the range, and the first range over signal A conversion range in which the conversion range is increased by one step when the number of times occurring within a predetermined period increases for each predetermined number of times, and the conversion range is lowered by one step when the number of times that the second range over signal occurs within a predetermined period is less than the predetermined number of times; Recording device, characterized in that consisting of a specified circuit Second amplifying means for storing a digital sound signal, second amplitude level detecting means for detecting an amplitude level in accordance with amplitude information of the digital sound signal, and sequentially outputting a digital amplitude signal according to the digital sound signal, and the digital sound Second amplitude level detection means for detecting an amplitude level according to the amplitude information of the signal and sequentially outputting the digital amplitude signal according to the digital sound signal, and selecting a second conversion range to select a conversion range based on the digital amplitude signal. Means for converting a digital sound signal into an analog sound signal at a conversion range selected by said second conversion range selecting means, wherein said second conversion range selecting means comprises: A comparator for generating a range over signal when it is larger than the maximum value of the selected conversion range, and the range over signal is constant. When produced it is greater than the predetermined number of times in the number of liver and reproducing apparatus characterized in that comprising the conversion range to a designated range conversion circuit to step up. Second storage means for storing a digital sound signal, second amplitude level detection means for detecting an amplitude level in accordance with amplitude information of the digital sound signal, and sequentially outputting a digital amplitude signal according to the digital sound signal, and the digital amplitude signal A reproducing apparatus comprising: second conversion range selecting means for selecting a conversion range based on the second conversion means; and second conversion means for converting a digital sound signal into an analog sound signal at the conversion range selected by the second conversion range selecting means, The second conversion range selecting means includes: a comparator for generating a rangeover signal when the digital amplitude signal is larger than the maximum value of the conversion range under one step of the currently selected conversion range, and the number of times the rangeover signal is generated within a predetermined period. A conversion range designation circuit for lowering the conversion range by one step when less than a predetermined number of times; Reproducing apparatus, characterized by. Second amplitude means for storing a digital sound signal, second amplitude level detection means for detecting an amplitude level in accordance with amplitude information of the digital sound signal, and sequentially outputting a digital amplitude signal according to the digital sound signal, and the digital amplitude A reproduction apparatus comprising: second conversion range selection means for selecting a conversion range based on a signal and second conversion means for converting a digital sound signal into an analog sound signal at the conversion range selected by the second conversion range selection means, The second conversion range selecting means generates a first range over signal when the digital amplitude signal is greater than the maximum value of the currently selected conversion range, and the second conversion range selecting means generates a first range over signal. A comparator for generating a second rangeover signal larger than the maximum value, and the first rangeover signal is constant A conversion which raises the conversion range by one step when the number of times occurring within a period is more than a predetermined number of times and decreases the conversion range by one step when the number of times that the second range over signal occurs within a predetermined period is less than a predetermined number of times; A reproducing apparatus, comprising a range designating circuit. A recording method in which an original sound signal is converted into a digital sound signal and stored in the converted digital sound signal at a conversion range width selected according to amplitude information of the original sound signal, and recording is performed. The conversion range width "A" is "AO". Conversion range width, "1" to "0"

integer variable of "i", "k" to "2"

Integer constant of k "," j "to" 0 "

j

k-1 "", where A = AO [(1/2) ¹ ] [(1/2) ^{j / k} ], where "i" and "j" correspond to the amplitude information. Recording method characterized in that the selection is appropriate. First selection means for selecting a conversion range according to amplitude information of the original sound signal, first conversion means for converting the original sound signal into a digital sound signal with a conversion range width corresponding to the conversion range selected by the first selection means, and the first A recording apparatus comprising a storage means for storing the digital sound signal converted by the conversion means, wherein the conversion range width "A" is "AO" as the maximum conversion range width and "i" as "0".

integer variable of "i", "k" to "2"

integer of k "," i "to" 0 "

j

k-1 "", where A = AO [(1/2) ¹ ] [(1/2) ^{j / k} ], where "i" and "j" correspond to the amplitude information. Recording method characterized in that the selection is appropriate. A reproducing method of reading and storing a stored digital sound signal and converting the digital sound signal into an anilog sound signal at a conversion range width selected according to the amplitude information of the digital sound signal for reproduction, wherein the conversion range width " A " AO "is the maximum conversion range width and" i "is" 0 "

integer variable of "i", "k" to "2"

integer of k "," j "to" 0 "

j

k-1 "", where A = AO [(1/2) ¹ ] [(1/2) ^{j / k} ], where "i" and "j" correspond to the amplitude information. Recording method characterized in that the selection is appropriate. Second storage means for storing the digital sound signal, second selection means for selecting a conversion range according to amplitude information of the digital sound signal, and a digital sound signal having a conversion range width corresponding to the conversion range selected by the second selection means. In the playback apparatus composed of second conversion means for converting an analog sound signal, the conversion range width "A" is "AO", the maximum conversion range width, and "i" is "0".

integer variable of "i", "k" to "2"

integer of k "," j "to" 0 "

j

k-1 "", where A = AO [(1/2) ¹ ] [(1/2) ^{j / k} ], where "i" and "j" correspond to the amplitude information. A reproducing apparatus, characterized in that appropriately selected.

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