JPS62170078A - Pcm sound signal recording and reproducing device - Google Patents

Abstract

PURPOSE:To record and reproduce a PCM sound signal together with a video signal without synchronizing relation with the frequency by controlling a data number recorded per field in response to the ratio of the field frequency to the sound signal sampling frequency. CONSTITUTION:A latch 50-1 of an address difference extraction circuit 50 latches an output of a write address circuit 17 and an output of a read address circuit 19. The latch output is inputted to a subtractor 50-2. The value subtracting the read address from the write address is inputted to a comparator 51-2 together with an output of a discrimination circuit 50-1. An in-field sampling number counter circuit 52 uses the output of the comparator 51-2 to control a selector 52-3 thereby setting the in-field sample number. An in-field sample number counter circuit 53 records '0' to the region of a control code in case of the sound signal and '1' in case of a data other than the sound signal when the output of the counter 53-2 reaches a decoded value selected by the selector 52-3 while using a signal 54 controlling the control signal circuit.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an apparatus for recording and reproducing encoded audio signals on a magnetic tape together with a video signal or alone using a rotary boron head scanner. This is particularly suitable when the sampling frequency of the digital audio signal and the rotational frequency of the scanner are asynchronous.

[Conventional technology]

PCM to improve the quality of the audio signal accompanying the video
Recording and reproducing methods have been introduced.

8uVideo uses the PCM audio system, but the pCMf voice double signal sampling frequency is twice the horizontal synchronization signal repetition frequency, which is the internationally generalized sampling frequency ( 32f#z, 44.1, K
H2 and 48ffZ, etc.). For example, the sampling frequencies of PCM audio signals of satellite broadcasting are 32 KHz and 48 KHz.

On the other hand, qUSE is one of the transmission methods for high-definition television.
In this method, the sampling frequency of the PCM audio signal is 32U and 48KHz, so if you try to record data sampled at the same sampling frequency in units of fields, 1
The number of data per field becomes omitted, causing inconvenience. As a way to resolve this inconvenience, NHK Giken Monthly Report 2
7-7 pp. 282, a bucket transmission system having a leap field (Seki field) for absorbing the remainder is used.

In addition, for video discs, PCs with the same format as compact discs and a sampling frequency of 44.1 KHz are used.
M audio signal is being recorded.

However, when attempting to record a PCM audio signal on a device such as a video tape recorder that records or transmits signals temporally discontinuously, the following problems arise. First, if the sampling frequency of the audio signal is not divisible by the field frequency of the video signal, the above-mentioned problems occur in encoding. For this reason, there is a solution such as the above-mentioned MUSE method, but in this case, the field frequency fy1 of the video signal, the rotation frequency fn of the head scanner that rotates in synchronization with this, and the sampling frequency fs of the audio signal. It is necessary to establish a synchronization relationship between them, and this is a condition that limits the range of application of the system.

Furthermore, as a device for recording and reproducing only audio signals in PCM on a rotary head type VTR, we have developed a consumer PC & encoder that complies with the Japanese Society of Electronic Engineers Technical Standards cPZ-105.
Decoder (enacted September 1983) is an example.

Examples of recording and reproducing devices based on this technology include Presented at the 69 Convenge Four 198
May 12-15, 2015 Los Angeles N.E. Nis 1791 (B-6) (Pres.
entered at the 69truC6nve
tion 1981 May 12 15 Lo
s Ar5quelex A E51791(B-6)
) paper, Digital Audio/Video Combination Recorder Using Custom Mates (Di,q)
ital Audio/Videa Combinat
ion Recorder Usir5q Co
5torn Made L S 11',
1 and 14 of 1/,).

In the same paper, for example, 525/60 (# T 5
C) In the case of method, field frequency order and sampling frequency f
s is divided from the same master clock, and there is fs between them.
” There is a relationship of 735fy, and therefore the number of samples per field is fixed at 735.

In addition, in the same paper, the sampled PCM signal was recorded and
A block diagram of the device configuration for playback is shown in FIG. 1 of the same paper. In the figure, an address control circuit controls the address of a RAM serving as an interleave memory.

However, in this example, the field frequency and the sampling frequency are 15
This is based on the assumption that there is a certain relationship between 1. and 1. No consideration was given to the case where there is no correlation.

[Problem that the invention seeks to solve]

In the above conventional technology, the sampling frequency of the audio signal is not an internationally generalized sampling frequency, the number of quantization bits is small, and there is a synchronization relationship between the audio signal sampling frequency and the field frequency. For example, if you try to record audio from a video signal from a camera and a digital signal from a CD (compact disc), etc.
It has been extremely difficult to record both at the same time because the sampling frequencies are different and there is no synchronization relationship between the sampling frequency and the field frequency.

SUMMARY OF THE INVENTION An object of the present invention is to realize a video tape recorder capable of recording and reproducing a PCM audio signal of an internationally generalized sampling frequency together with a video signal of a field frequency that has no synchronization relationship with this frequency.

[Means for Solving the Problems] The above object is achieved by controlling the number of sample values (number of data) recorded per field in accordance with the ratio of the field frequency and the audio signal sampling frequency.

This control method is made possible by changing the number of data in one data frame, which is the basic unit of data processing.

[Effect]

To this end, means for detecting the ratio between the audio sampling frequency and the video field frequency detects the same ratio, and the number of data in the data frame is controlled according to the result. That is, if the above ratio is large, increase the number of data,
On the other hand, if this ratio is small, by controlling to reduce the number of data, it becomes possible to correspond to various sampling frequencies and video field frequencies.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 shows the configuration of a rotating head type PCM signal recording and reproducing apparatus.

During recording, two channels of H analog signals are input from input terminal 1. The input signal is amplified to a predetermined level by an amplifier circuit 2, limited in its entire range by a filter 3, and then sampled by a sample hold circuit 4. The sampled human input signals are sequentially input to the A/D converter 6 by the switching circuit 5 and converted into PCM signals. The PCM signal converted by the Aμ converter 6 is written into the RAM 15 through the pass line 14. Then, the addresses of the RAM 15 are controlled by the address generation circuits 17 to 19 and the address switching circuit 16, and the arrangement of PCM signals and the addition of error correction codes are performed according to a predetermined formant. Note that the addition of the error correction code is performed using the error correction circuit 20. After the PCM signal has been arranged and the error correction code has been added, each piece of data is sequentially read out from RA & 15. At this time, the read address generation circuit 19 uses the in-field sample number counting circuit 5.
The number of audio signal samples in one field counted in step 3 is calculated based on the signal determined by the difference determination circuit 51 from the difference between the write-in address and the read address extracted by the address difference extraction circuit 50. The number of samples is controlled to be the number of samples set by the number of samples setting circuit 52. The signal read from the RAM 15 is converted into a serial signal by a parallel-to-serial conversion circuit B. Then, when the number of audio signals in the l field is small, the control signal generation circuit 24 and the switching circuit 4 generate a signal other than the audio signal, a code for determining whether it is an audio signal or a signal other than audio, and synchronization. A modulation circuit 36 modulates predetermined data by adding a control signal such as a signal. Then, it is amplified to a predetermined level by the recording amplifier 26, and the hunting tape 32 is output from the audio rotary head 31, for example.
recorded on the surface or deep layers of The switching circuit 30 switches between recording and reproduction. Further, the timing generation circuit 21 is a circuit that generates a timing signal that controls the entire system using a clock generated by the oscillation circuit 22.

During reproduction, the switching circuit 30 is switched to the reproduction side, and the signal reproduced by the audio rotating head 31 is amplified to a predetermined level by the reproduction amplifier 29, and the signal is amplified to a predetermined level by the waveform equalization circuit 3.
7 performs waveform equalization. The waveform equalized signal is
The demodulation circuit 38 demodulates the signal and converts it into a digital signal. The demodulated digital signal is subjected to detection of a synchronization signal by a synchronization detection circuit and conversion into a parallel signal by a tray conversion circuit 27. The detected synchronization signal is used as a reference for data reproduction. The signal determination circuit 44 determines whether the data converted into a parallel signal is an audio signal or a signal other than an audio signal, and only the audio signal is sent to RA Af.
The audio signal and data other than the audio signal are also stored in the RA and K 15 to rearrange and correct the data. The signals are input to the D/A converter 12 through the pass line 14, sequentially converted into analog signals, and resampled for each channel in the sample-and-hold circuit 11. The signal is output from the output terminal 8 through the amplifier circuit 9.

At the time of recording, the video signal is inputted from the input terminal 40, converted into a predetermined signal by the video circuit 42, and recorded on the tape 33 by the video rotation gutter 43.

During reproduction, the key signal reproduced by the video rotating head 43 is converted into a predetermined signal by the video circuit 42,
It is output from the output terminal 41.

A specific circuit configuration of the present invention will be explained using FIG. 2.

This figure is a circuit diagram of the RA during recording, and the child write and read address portions. The write address circuit 17 is composed of a counter 17-1. Read address circuit 1
9 is a counter that divides the master clock by 8 19-1
and a counter 19-2 that divides the 8-frequency output by 32;
For example, the output divided by 32 is 525/60 (N T 5
It consists of a counter 19-3 which divides the frequency by 142 in the VTR of C) and by 170 in the VTR of 625150 (PAL).

The latch 50-1 associated with the address difference extraction circuit latches the output of the write address circuit 17 and the output of the read address circuit 19 at the transition point of the head switching signal 45 extracted by the exclusive OR gate 21-3. . The latch output is input to the attenuator 50-2.

Here, the value obtained by subtracting the read address value from the write address value is input to the comparator 51-2 together with the output of the judgment value circuit 51-1, and is greater or smaller than the output of the judgment value circuit 51-1. It is determined whether The in-field sample number counting circuit 52 includes a selector 52 that selects counter decoded values 52-1 and 52-2 based on the output of the comparator 51-2.
-3 to set the number of samples in the field. That is, when the output of the subtracter 50-2 is larger than the output of the judgment value circuit 51-1, the number of audio data is increased so that the output of the subtracter 50-2 becomes the output of the judgment circuit 51-1. When the number is smaller than , the decoder 53-1 is set to reduce the number of audio data. In-field sample number counting circuit 5
3, when the output of the counter 53-2 reaches the decoded value selected by the selector 52-3, the signal 54 that controls the control signal circuit 24 outputs "0" if it is an audio signal, for example.
, if the data is other than an audio signal, "1" is recorded in the control code area.

FIG. 3 shows a recording pattern on a magnetic tape.

+azimuth tracks 34 and -azimuth tracks 35 are alternately recorded on the magnetic tape 33. In each track, a video signal and an audio signal are recorded separately into a surface layer or a surface layer and a deep layer. Alternatively, only the audio signal is recorded in the surface layer or both the surface layer and the deep layer.

VTR with rotating head type PCM symbol recording and reproducing device
The data array when using is explained below.

When recording 16-bit audio on a VTR, the cylinder rotation speed of the VTR is approximately 1798.2 mm, so one field will have 800.8 samples. Therefore, in this case, the number of samples within one field period is, for example, SOO
Samples, 801 samples, or some other number must be used, and consideration must be given to matching the number of data in multiple fields.

Next, a configuration example will be described in which the data arrangement configuration of one field conforms to the format of a rotary head digital audio tape recorder (R-DAT). Fourth
Incidentally, a PCM signal with 2 channels and 1 word of 16 bits is divided into 8-bit symbols, and four data or parity symbols, a synchronization signal, an ID code including a control signal indicating the type of data, a block address, and a parity code are divided into 8-bit symbols. The data structure is shown in which 4 symbols are added to make one block with a total of 36 symbols. This block is 525/60 (
For example, 142 blocks, 625150 in NTSC) system.
For example, 170 blocks of data are recorded in each dock using the (PAL) method. Further, even if a large burst error occurs, an error correction code equivalent to R-DAT is added or data is distributed so that the error can be corrected. As an example of distribution, assume that even-numbered data is recorded in the first half of the track, and odd-numbered data is recorded in the second half of the track.

As an example of data arrangement, a data recording method will be described below in which 128 blocks constitute one data frame and 142 blocks are recorded within one video field period.

FIG. 5 is a timing chart of the signal processing and recording system. In the figure, +11 indicates the field period of R-DAT, and one frame period is 30 m5ec.

One field period is 15 mtec. (
2) indicates the data frame period, one data frame is composed of 128 blocks and is recorded within the field period of (1). As described above, in R-DAT, the field period of the recording system and the data frame processing time of the signal processing system are completely synchronized. On the other hand, as shown in (3), the field period of the video signal is 16.7mztc in the 524\'60 system and 20m5 in the 625/50 system.
ec, and in this embodiment, 142 blocks or 170 blocks are recorded within one field period as shown in (41).

This is further converted to 170.4/180 using the 525/60 method.
, 625150 method to compress the time axis to 1707180 (as shown in 51, the head rotation angle is recorded in the area of 1704" or 17o0.

FIG. 6 shows the data structure of one field generated in this way. In one field, 142 blocks of data are recorded in the 525/60 format, and 170 blocks of data are recorded in the 625150 format, regardless of the joints between data frames. Each block has a 6th
As shown in the figure (α), block addresses are recorded, and any one of addresses 0 to 127 corresponds to each block address. Data signal processing consists of 128 blocks from O to 127.
That is, the processing is performed in units of one data frame. The data arrangement within the data frame will be explained in detail later. Now, in this embodiment, the data of the above 142 blocks or 170 blocks is converted into a head cylinder rotation angle of 170.4.
The time axis is compressed and recorded in an area of 170° or 170°.

The area where such data is recorded is called a data area. Of the areas to be recorded, the portions excluding the data area are called a preamble and a postamble on the input side and output side of the head, respectively, and PLL signals for data strobe and the like are recorded therein. In the case of this embodiment, the preamble and postamble are 4 blocks in 525/60 format.
In the 625750 system, data is recorded in an area corresponding to 5 blocks. On the other hand, one block of data is (b) in Figure 6.
), it consists of 36 symbols, or 288 bits. Of these, the four most rib symbols are synchronization signals (5Y
NC) Additional data (ID), address signal (ADH).

and a parity signal (PARITY) which is the modulo-2 addition result for each bit of the additional data and address signal. The following four symbols are audio data (PCM-data).
) or C2 parity generated from audio data (
C'l Party) signal. The last four symbols are C1 parity (('
I Parity) N.

In a method of recording digital audio together with a video signal, in order to avoid deterioration of the quality of the digital audio signal, the reproduced signal from the digital audio signal source, such as a digital audio tape recorder, is input in its digital form. Since the data rate of the digital audio signal in this case depends on the signal source, it is asynchronous with, for example, the field or frame period of the video signal source. Furthermore, as in the embodiment of the present invention, since the recording is discontinuous in field units, it is necessary to determine the number of samples to be included in one field period of the video signal for the digital audio signal as well. However, due to the asynchronous relationship, the constant number is not necessarily an integer number of samples.

In order to achieve such asynchronous absorption, in the embodiment of the present invention,
This is handled by making the number of digital audio samples in the data field variable.

The present invention treats 128 blocks of a digital audio signal as a data frame, and completes interleaving and coding within the data frame. Since 1 field is not synchronized with 1 data frame,
One or more data frames are recorded in one field.

Examples of data frame complete interleave formants will be explained below, divided into four types depending on the sampling frequency and the number of channels of audio (K).

FIG. 7 shows types of data frame complete inter-IJ formats. In mode 1, the number of audio signals is 2ch, the sampling frequency is 48KH2°, and the quantization number is 16 bits. Also, quantization number 16 bit t is 8
This is divided into bits and is considered as 1 data, and since there are approximately 66.67 (=2000730) data frames per second, 48Uz x 2ch x 2 data / (2000/30)
= 2880 data, and 2880 data are recorded in one data frame as standard. In the present invention, when the number of data in one field is not constant, recording using a fixed data frame is made possible by increasing or decreasing the number of data in the data frame from the standard number of data.

In mode 2, 32KHz x 2 c A x 2 data/(200
0/30 ) = 1920 In data mode 3, 32 - IIzX4cA x 2XL2 - data / (200
0/30) = 2880 theta b In mode 4, 44, lX2cAX2 data/(2000/30) = 2
646 data is handled as the standard number of data in one data frame.

Next, the interleave format within the data frame in each mode will be explained.

Figure 8 shows the number of audio signals: 2 channels, sampling frequency: 48 KHz.
.

This is an interleave format in one data frame when the quantization number is 16 bits. A 16-bit digital audio signal is divided into upper and lower data of BB bits, and these are distinguished by the subscript L.

Also, the 2 cA audio signal is distinguished by R.

The maximum number of samples that can be recorded in one data frame is L, R.
Both are 728, which is expressed by subscripts from φ to 727. The data are Lφμ, Lφl, Rφμ, Rφt.

LLLL, LLL, Rlu, RHL, =
, L7! ? ”, L727t, R717u, R
-1211 in the order of 104 in the data frame
Configure the blocks. From this data, 24 Q parity blocks are generated, resulting in 128 blocks.

Furthermore, 4 P parities are added to each block, resulting in 32
128 blocks consisting of I@ data and parity
A block is constructed, and this is defined as one data frame. When recording on tape, block addresses φ, 1, 2, .・・・
127. Perform in this order. Therefore, adjacent data at the time of sampling can be distributed and recorded.

As a result, even if burst errors occur due to scratches on the tape or other reasons that result in consecutive data errors, the burst errors can be dispersed by interleaving, and the data can be corrected using parity. It becomes possible to correct missing data.

Also, since the field frequency and the audio signal sampling frequency are different, recording is possible by increasing or decreasing the data in the data frame, but when the number of data is small, Lφu, Lφ
t” L?1B” r L! 15t and Rφμ, Rφ
t.

~+ L711ULy L! +116 data, when the number of data is large, Lφu, LφZ-Lnqu, L,
ttl and Rφu, Rφt"""717" +
This is made possible by configuring one data frame with 'tt71- data.

The increase/decrease in the number of data within a data frame is as follows: a data frame with data of φ~715 and a data frame of φ~727 for both L and R.
For both L and R, a data frame with standard data numbers φ~719, a data frame with φ~715 data, and a data frame with φ~727 A method of switching between three data frames, L and R both φ~7
A possible method is to switch between data frames having an arbitrary number of data between 15 and φ~727.

FIG. 9 shows a data frame interleave format when the number of audio signal channels is 2ch, the sampling frequency is 32Hz, and the number of children is 168bit.

The number of arson samples is 486 for both L and R, and the data frame has Imabari where data is added, but this part is
Do not use as blank data.

Q parity and P parity are added in the same manner as shown in FIG. 3-2.

The increase/decrease of the data frame due to the change in the number of samples in the field is performed between the minimum φ ~ 476 and the maximum φ ~ 485 for both L and R, and there are three ways to switch between two, three, or arbitrary data frames. There are possible ways.

Figure 10 shows a sampling frequency of 32ff, a quantization number of 1'
This is a data frame interleave format when the number of zit audio signal channels is 4ch. Data is BB
Since it is handled in units of tt, the digital audio signal data is 12B.
Divide it into the upper 8 Bits and the lower 4B number t, and the upper 8 B
it i'1Aiu, BiLL, Ciu, D
iu, the lower -'lht is the two digital audio signal data combined as BBit, and l(,'ij
, , BDit.艮 is a subscript indicating the order of digital audio signal data, and L2 in one data frame.
Bit, 4cl data, maximum 485 people. Further, A, B, C, and D indicate 4ch audio signals.

The data are Aφ, , ACφt, Cφu, Bφ, ,
HDφL, Dφμ”・r Atuu l ACu4t
+ C4MW * Bulku * BD484t+
Sorted into the data frame in the order of D4841A,
104 blocks are constructed, 24 Q parity blocks are generated, and P parity is added to each block. One data frame consists of 128 blocks of data and parity.

Also, one data frame can contain up to 485 x 4ch digital audio signal data, but since 4ch data is treated as a unit, the maximum number of data in a data frame is:
It makes a difference. This is blank data, which is more than two pieces of data.

The increase/decrease of data in the data frame is performed for both channels A to D4 between a minimum of φ ~ 476 and a maximum of φ ~ 484,
There are 34 ways to switch between two, three, or arbitrary data frames.

In FIG. 11, the number of audio signal channels is 2ch and the sampling frequency is 44. This is a data frame interleave format at IKHz, im childization number 16 bits.

The maximum number of samples is 669, and one data frame contains 720 pieces of data, but the rest is blank data.

Q parity and P parity are added in the same manner as shown in FIG. 3-2.

The increase/decrease in data frames due to changes in the number of samples in a field is performed between a minimum of φ~657 and a maximum of φ~668 for both L and R, and data frame switching is performed by switching between two data frames and three data frames. There are three possible methods: switching, and switching arbitrary data frames. FIG. 12 shows a data arrangement diagram of Q and C2 parity for error detection/correction and PCM audio data in this system. After the sampled PCM audio data is arranged with the even and odd numbers of each channel separated, 02 parity is generated in the block address direction, 01 parity is generated in the recording direction, and the PCM audio data within one data frame is Configure data. At this time, the even numbered PCM data is stored in the block address 0 to 51, the odd numbered data is stored in the area 76 to 127, and the C2 parity is stored in the block address 52 to 127.
75 areas.

During recording, audio data is recorded in blocks, with 142 blocks in the 525/60 (NTSC) system in one field period, and 4 block periods before and after.

It is recorded with additional data. Also 62s/5O
In the (PAL) system, 170 blocks of audio data are recorded with 5 block periods of ampoule data added before and after the audio data. At this time, audio data is recorded as multiple data frames adjacent to each other, so if a playback error occurs due to scratches or the like between adjacent data frames, the PCM audio data area may be destroyed, or error detection and correction may occur. There is a high risk of erroneous detection or erroneous correction by the circuit.

Therefore, as another example, 02 parity is shown in FIG.
A case is shown in which the data frame is divided into two parts before and after the CM audio data, that is, at both ends of the data frame. At this time, C2 parity is stored in areas of block addresses 0 to 11 and 116 to 127, and PCM audio data is stored in areas of block addresses 12 to 115.

As another example, FIG. 14 shows C2 parity in PCM
This shows the case where it is placed before the data, that is, at the front in the data frame. At this time, C2 parity is an area of block addresses 0 to 23, and PCM audio data is 24 to 127.
is stored in the area.

As another example, 02 parity is shown in FIG.
It may be placed after the data, that is, at the rear of the data frame. At this time, C2 parity is an area of block addresses 104 to 127, and PCM audio data is an area of 0 to 1.
It is stored in area 03.

As another example, as shown in FIG. 16, the 02 parity may be divided into two parts and placed at the front of the even and odd terms p c and w audio data. At this time, C2 parity is the area of block addresses 0 to 11 and b4 to 75, and the even term P
CM audio data is stored in areas 12 to 63, and odd-numbered PCM audio data is stored in areas 76 to 127, respectively.

In this way, by arranging the vA area of the C2 parity at the front, front, or rear of the data frame, there is an effect of protecting the PCM audio data against playback errors between data frames. This is advantageous in an algorithm that outputs audio data without correcting it when the number of errors exceeds a certain number.

〔Effect of the invention〕

According to the present invention, PCM is performed using a rotating magnetic head type scanner.
When recording and reproducing audio signals together with video 1-band signals, what is the rotational frequency of the head scanner and PCM sound? Since there is no security in maintaining a synchronization relationship with the sampling frequency of the signal, it is possible to record/record by combining any video signal and PCM audio signal.
Can be played.

[Brief explanation of drawings]

FIG. 1 shows the block cause of one embodiment of the present invention, and FIG. 2 shows the RA
A circuit diagram of the M control circuit, Fig. 3 is a diagram showing the recording format on the tape, Fig. 4 is a configuration diagram of one block, Fig. 5 is a diagram showing the recording system and data processing control circuit, and the sixth factor is the circuit diagram of the M control circuit. is a diagram showing an example of the configuration of one field, Figure 7 is a diagram showing audio signal specifications, Figure 8 is a diagram showing the interleave format of mode 1, Figure 9 is a diagram showing the interleave format of mode 2, and Figure 10 is a diagram showing the interleave format of mode 2. The figure shows the interleave format of mode 3, Figure 11 shows the interleave format of mode 4, Figure 12 shows the data format with C2 parity placed in the center, and Figure 1J shows the C2 parity.
Data format diagram with parity placed at both ends, 1st
Figure 4 is a data format diagram with C2 parity placed at the beginning, Figure 15 is a data format diagram with C2 parity placed at the end, and Figure 16 is a data format diagram with C2 parity placed at the beginning of even and odd terms of audio data. It is a diagram of the arranged data format. 16... Address switching 17... Write address 18... Correction address 19... Read address (capital)... Address difference extraction 51... Difference judgment 5
2...Setting the number of samples in the field 53...Counting the number of samples in the field/-1 agent Patent attorney 10 Masaru Ogawa 1 = 418 42 No. 37 Symposium 12 Figure 13 Figure 14th figure

Claims (1)

[Claims] 1. Sample the audio signal accompanying the video signal, convert it to a PCM signal, add error detection and correction data to a predetermined number of PCM data, and construct a data frame made of these signals. In a PCM audio signal recording and reproducing apparatus that records an audio signal together with a video signal or alone on a recording medium after performing modulation based on a predetermined modulation method, a digital signal processing circuit equipped with a memory of a predetermined capacity is used. and changing the number of digital data in the data frame according to the difference between the number of input data of the digital audio signal to the digital signal processing circuit and the number of output data output for recording on a recording medium. What is claimed is: 1. A PCM audio signal recording and reproducing device, characterized in that the PCM audio signal is recorded by