JPH09161401A - Digital signal recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently utilize the capacity of a recording medium by allowing digital signals with a plurality of bit lengths to exist together. SOLUTION: The essential data capacity within a fundamental unit is 15, 360 bytes (1,024 (1K)×15) and three types of bit lengths (16/20/24(bits)) are prepared. The amount of data of the fundamental unit is the common multiples of the bit lengths and is also the multiples of 512 bytes. The essential data and other additional information AUX (User data = 64×15=960 bytes, control data = 64 bytes) together form the fundamental unit. However, in this case, the capacity of the total fundamental units is 16, 384 bytes (1,024 (1K)×16) and 1,024 bytes are secured for the additional information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital signal recording method for recording a digital audio signal on a magnetic or optical recording medium, for example.

[0002]

2. Description of the Related Art Conventionally, in many recording methods of digital recorders used for audio, the quantization bit length is fixed at 16 bits. Along with the recent improvement in sound quality, higher bit length is being considered.

[0003]

However, the conventional digital recorder cannot record / reproduce data in which audio data having a plurality of bit lengths are mixed. For example, in a digital multi-track recorder, it is difficult to select a bit length according to the sound quality of an audio signal recorded on each track and mix a plurality of bit lengths.

Further, in order to mix a plurality of bit lengths, simply inserting low bit length data (for example, 16 bits) into a high bit length recording method (for example, a recording format corresponding to 24 bits) is not used. Would increase the useless recording area. Therefore, there is a need for a recording / reproducing method with a mixed bit length that enables effective use of the recording medium.

Therefore, an object of the present invention is to provide a digital signal recording method in which digital signals of a plurality of bit lengths can be mixed and the capacity of the recording medium can be used without waste.

[0006]

According to the present invention, there is provided a digital signal recording method for quantizing a temporally continuous signal and treating a plurality of quantized data as a basic unit. It is characterized in that a plurality of quantized bit lengths are prepared, and that the data capacity that substantially occupies in the basic unit is all common multiples of the prepared quantized bit lengths and is a multiple of 512 bytes. This is a digital signal recording method. Further, the present invention is a digital signal recording method characterized in that the basic unit is multiplied by an integer in accordance with the ratio of all prepared quantization bit lengths, and the integer unit is the minimum recording unit. . further,
The present invention is a digital signal recording method characterized in that two or more kinds of time-series signals are quantized with a prepared quantized bit length, and the quantized unit is recorded as a minimum recording unit.

Since the amount of quantized data in the basic unit is a common multiple of the prepared bit lengths, no wasteful area is generated. Moreover, since the basic unit is a multiple of 512 bytes, it can be used as a peripheral device of a computer.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to recording / reproduction of audio data will be described below. FIG. 1 shows a data structure according to an embodiment of the present invention. In this embodiment, the substantial data capacity in the basic unit is 15,360 bytes (1,024 (1K) × 1).
5), and three types of bit lengths, 16/20/24 (bits), are prepared. The data amount of the basic unit is a common multiple of these bit lengths, and is also a multiple of 512 bytes.

In recent years, computer peripherals such as MO (magneto-optical) disk drives and hard disks have been generally used for data recording. In such a case, it is a multiple of the basic unit of these accesses, for example 512 bytes. Therefore, the amount of data is 512
By making it an integral multiple of bytes, it can be used as a peripheral device of a computer.

Further, although the substantial data may be directly assigned to all the basic units of the present invention, in this embodiment, the substantial data and other supplementary information AUX are provided.
(User data = 64 × 15 = 960 bytes, control data = 64 bytes) are combined to form a basic unit. However, in that case, the total basic unit capacity is 5
Since it is preferable that it is a multiple of 12 bytes, the total capacity of basic units is 16,384 bytes (1,02
4 (1K) × 16), and 1,024 bytes are reserved for the incidental information therein.

FIG. 2 shows the relationship between each bit length and the number of words in the substantial data area in one embodiment of the present invention. In FIG. 2, the vertical axis represents the bit length and the horizontal axis represents the number of words. The capacity of the data that substantially occupies in the basic unit is constant at (1,024 × 15) bytes, but the number of words in the sampling frequency unit quantized with each bit length is different. The capacity in terms of the number of words is the reciprocal ratio of the ratio of each bit length. As shown in FIG. 2, the bit length is 16/20/24 bits, that is,
In the case of 4: 5: 6, the number of words is 1 which is the inverse ratio.
It will be 5:12:10.

Also, the supplementary information AU of the embodiment of the present invention.
X is composed of two pieces of user data that provides 1-bit information for each word and control data that provides other information in a fixed number of bytes. Therefore, the effective number of bytes of user data differs depending on each bit length. When the length is 16 bytes, the number of valid bytes is 960 bytes, when the length is 20 bits, the number of valid bytes is 768 bytes, and when the length is 24 bits, the number of valid bytes is 640 bytes.

Fixed byte length (eg 64 bytes = 512)
The control data provided in (bit) is set to a common divisor for the number of words of data in each bit length. The control data is a flag corresponding to the presence / absence of emphasis, parity data for error correction, and the like. As a result, when the control data is output by combining 1 bit for each word, by repeating 512 bits, the word data of all bit lengths can be repeated an integer number of times and be completed within the basic unit. Is possible. That is, 15 times for a 16-byte length and 12 for a 20-byte length.
In the case of a 24-byte length, 512 bits are repeated 10 times.

FIG. 3 shows a basic unit structure and a minimum recording / reproducing unit structure according to an embodiment of the present invention. The minimum recording / reproducing unit on the actual recording medium is an integral multiple of the basic unit of each bit length. In this one embodiment, FIG.
As shown in FIG. 7, in each bit length of 16/20/24 bits, the 8/10/12 basic unit is treated as the minimum recording / reproducing unit.

That is, although the number of bytes of the minimum recording / reproducing unit in each bit length is different, the substantial number of data words in it is constant regardless of the bit length. In this embodiment, the number of words in the minimum recording / reproducing unit is constant at 61,440 words. In other words, when recorded, it is guaranteed that the substantial data in the minimum recording / reproducing unit is temporally constant. In this way, by making the number of words of the minimum recording / reproducing unit constant, it is possible to make the configuration of the portion that processes data common in the recording / reproducing apparatus regardless of the bit length, which facilitates hardware design. Becomes That is, it is not necessary to switch the number of words for processing.

FIG. 4 shows a recording / reproducing apparatus for carrying out an embodiment of the present invention. Reference numeral 15 surrounded by a broken line is a recording / reproducing control unit, and reference numeral 35 surrounded by a broken line is a recording / reproducing apparatus such as a hard disk device or an MO disk drive device. The recording / reproduction control unit 15 uses the time-series signal input terminal 1
a, user data input terminal 1b, control data input terminal 1c, A / D converter 2, recording buffer 3, data converter 4, minimum recording unit buffer 5, data I / F
(Interface) 6, minimum reproduction unit buffer 7, data converter 8, reproduction buffer 9, D / A converter 10,
Time series signal output terminal 11a, user data output terminal 1
1b, a control data output terminal 11c, a recording / reproducing address management unit 12, and a recording / reproducing address designating unit 13.

Further, the recording / reproducing apparatus 35 uses a data I / F.
21, memory 22, recording processing circuit 23, reproduction processing circuit 2
4, memory 25, recording / reproducing address control unit 26, modulator 2
7, a demodulator 28, a position control motor 29, a recording / reproducing head 30, a recording medium 31, and a rotation motor 32. The recording / reproducing control unit 15 and the recording / reproducing device 35 are connected by a data transfer path 40 such as SCSI.

In FIG. 4, the recording time series signal input from the time series signal input terminal 1a is sampled by the A / D converter 2 in accordance with the bit length RBL designated by the user.
Quantized. This data is collected in the recording buffer 3 into a minimum recording unit of 61,440 words.
Furthermore, the user data input from the user data input terminal 1b and the control data input from the control data input terminal 1c are supplied to the recording buffer 3. The user data and the control data are not limited to being supplied from the outside, but may be generated internally.

Here, the recording buffer 3 has 61, 44
A capacity for N pieces of a minimum recording unit of 0 word is prepared. This is because there is no guarantee that recording will be performed immediately in the recording device when one recording unit is completed. It is ensured for the purpose of preventing the time-series data that is sequentially input from overflowing before the actual recording is completed. The number of N is required to be at least 2, but a larger number is preferable in order to average the delay time until the end of recording.

61, 4 collected in the recording buffer 3
The minimum recording unit of 40 words is a unit common to all bit lengths as described above, but the data amount changes depending on the bit length. Therefore, the storage capacity of the recording buffer 3 needs to be adjusted to the maximum bit length. Further, since 61,440 words of the recording buffer 3 are substantial data in a recording unit, it is necessary to convert this into a data format which is an integral multiple of the basic unit.

In the data converter 4, the data of 61,440 words is converted into a basic unit based on the information of the bit length RBL designated by the user. At this time, the additional information in the basic unit is added at the same time, and the minimum recording unit buffer 5 is added.
Stores data in the form of an integral number of basic units.

The data converted into the minimum recording unit is recorded on the disc-shaped recording medium 31 by the recording / reproducing device 35. The recording / reproducing device 35 may use a tape as a medium, but since the address (position) to record can be an arbitrary place on the recording medium, it is advantageous to use a disk device or the like.

When recording the minimum recording unit, the recording / reproducing address management unit 12 searches for an empty area of the recording medium 31 and notifies the recording / reproducing address designating unit 13 of it. By this, the actual recording address is specified.
The recording address designated as the data to be recorded is sent to the recording / reproducing device 35 via the data transfer path 40.

The data to be recorded and the data at the designated recording address are subjected to error correction code addition, interleave processing, and synchronization signal addition in the recording processing circuit 23, and this signal is passed through the modulator 27 to the recording / reproducing head 30. And the position control motor 29 via the recording / reproducing address control unit 26. Then, the position control motor 29 moves the recording / reproducing head 30 to a designated recording address on the recording medium 31 rotated by the rotation motor 32. Then, the data to be recorded is recorded on the recording medium 31.

In the case of reproduction, first, the recording / reproducing address management unit 12 determines the reproducing position of the recording medium 31, and designates this position as the reproducing address to the recording / reproducing device 35.
In the recording / reproducing apparatus 35, the recording / reproducing head 30 searches the recording medium 30 for this designated address via the recording / reproducing address controller 26 and the position control motor 29. Then, the minimum reproducing unit in that area is set to the recording / reproducing head 3
0 is read out, and the reproduction processing circuit 24 is read through the demodulator 28.
Then, error correction processing, deinterleave processing, and synchronization signal detection are performed, and this signal is transferred to the minimum reproduction unit buffer 7 of the recording / reproduction control unit 15.

Since the minimum reproduction unit buffer 7 has a format in which the data is an integral multiple of the basic unit, the user can use the data converter 8 to convert 61,440 words, which is the substantial data in the minimum reproduction unit, to the data converter 8. Data is converted according to the instructed bit length PBL. Then, the converted signal is transferred to the reproduction buffer 9 and the additional information is extracted.

From the reproduction buffer 9, it is necessary to guarantee that the data is sent to the D / A converter 10 continuously in time series. Therefore, the buffer amount is increased to absorb the discontinuity of data acquisition from the recording / reproducing device 35. The reproduction buffer 9 has 61.4 bytes regardless of the bit length.
40 words are assigned to one minimum playback unit,
The word bit length must be the maximum.

Therefore, the D / A converter 10 converts data according to the bit length PBL designated by the user,
A time series signal is taken out from the time series signal output terminal 11a. Further, the user data is extracted from the user data output terminal 11b, and the control data is extracted from the control data output terminal 11c.

As described above, in the embodiment of the present invention, the configuration can be unified regardless of the bit length, and the minimum recording unit is changed according to each bit length. It is possible to use the capacity effectively.

It should be noted that the present invention is not limited to this one embodiment, and in the embodiment of the present invention, one type of time series signal is used, but when two or more time series signals are handled. You may apply to it. In this case, it is necessary to provide the recording / reproducing control unit 15 and the recording / reproducing device 35 in parallel according to the number of time-series signals. Further, a method of setting an arbitrary bit length for each time series signal may be used. Such various modifications are possible.

[0031]

According to the present invention, since the substantial amount of data in the basic unit can be set to a common multiple of the quantized bit length, a common basic unit can be provided for a plurality of bit length data. Since the minimum recording / reproducing unit can be set to an optimum amount according to each bit length, the recording medium can be effectively used without waste.

Further, according to the present invention, since the number of words is constant in the minimum recording / reproducing unit regardless of the bit length, it is guaranteed that the recording time of data is constant and the system can be easily designed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a data structure according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a relationship between each bit length and the number of words in a substantial data area in the embodiment of the present invention.

FIG. 3 is a schematic diagram showing a configuration of a basic unit and a configuration of a minimum recording / reproducing unit according to an embodiment of the present invention.

FIG. 4 is a block diagram showing a recording / reproducing apparatus for carrying out an embodiment of the present invention.

[Explanation of symbols]

 3 recording buffer 4, 8 data converter 5 minimum recording unit buffer 7 minimum reproduction unit buffer 9 reproduction buffer 15 recording / reproduction control unit 31 recording medium 35 recording / reproducing apparatus

Claims (3)

[Claims] 1. A digital signal recording method in which a temporally continuous signal is quantized and a plurality of quantized data are collectively treated as a basic unit, and a plurality of quantized bit lengths for the quantization are prepared. At the same time, the capacity of the data substantially occupied in the basic unit is all common multiples of the quantized bit length prepared,
In addition, the digital signal recording method is characterized in that it is a multiple of 512 bytes. 2. The digital signal recording method according to claim 1, wherein the basic unit is multiplied by an integer in accordance with the ratio of all the quantized bit lengths prepared, and the integral unit is the minimum recording unit. A digital signal recording method characterized by the following. 3. The digital signal recording method according to claim 2, wherein two or more kinds of time-series signals are quantized by prepared quantization bit lengths, and the quantized unit is set as a minimum unit of the recording. A digital signal recording method characterized by recording.