JPH02220290A - System and device for recording midi signal - Google Patents

Abstract

PURPOSE:To prevent the deviation between the period of playing data and that of rhythm at the time of reproducing a MIDI signal by continuously recording a rhythm stop signal, a rhythm start signal, etc., at the start timing of a rhythm pattern in each repeat period of the pattern. CONSTITUTION:When a rhythm machine 4 is started, a rhythm start flag is set to '1' because rhythm start data A is obtained, and a set value stored in a RAM 52 is decremented and rhythm clock data 8 is sent when the data is received thereafter. When the set value is decremented, respective commands of rhythm stop FC, rhythm start FA, and rhythm clock F8 are successively continuously sent because the counted value is 0, and the counted value is set again. By the processing, a set of stop FC, start a, and clock 8 are inserted before every two measures after the start of rhythm. Consequently, the rhythm machine is accurately started though reproducing of a CD is started from an arbitrary position, and flaws of the CD have not an influence.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a digital signal recording method and device, and in particular to a MIDI signal recording method and a digital signal recording method for controlling an electronic musical instrument.
The present invention relates to an IDI signal recording device.

[Prior Art] There is a MIDI standard for driving and controlling various electronic musical instruments using digital signals according to a predetermined format. Keyboard devices, electronic musical instruments, etc. have already been put into practical use in accordance with this MIDI standard, and it has become possible to drive a large number of electronic musical instruments by operating a single keyboard device.

Additionally, the applicant has previously recorded 8-bit data based on the MIDI standard (hereinafter referred to as MIDI words) on a magnetic tape, and by playing this data, it is possible to drive one or more electronic musical instruments without operating a keyboard. We have developed a digital information recording and recording/playback method and have applied for a patent. This is a helical scan type magnetic recording and reproducing device that uses MIDI words to store digital information related to the performance of musical instruments, that is, musical instrument control information such as pitch, scale, and length of notes, as shown in Japanese Patent Application Laid-open No. 82-146470. The MIDI signals are recorded in advance in a computer, played back, a start bit and a stop bit are added, and a 10-bit MIDI signal is applied to each musical instrument to drive it.

[Problems to be Solved by the Invention] If the magnetic recording/reproducing device described above is used, a MIDI word consisting of 8 bits excluding the start bit and stop bit from a MIDI signal consisting of a total of 10 bits including a start bit and a stop bit can be converted as is. It can be recorded and played back on magnetic tape, but the compact disc subcode is M.
IDI words could not be recorded and played back on a compact disc player. This is one MI
While the DI word consists of 8 bits, one of the subcodes of a compact disc (hereinafter referred to as CD)
Since the part of the frame excluding the 2 bits used for time code etc. consists of 6 bits consisting of R, S...W, it is not possible to record MIDI words as they are on the subcode channel of a CD. It is. Also, the transmission rate is 3,8008 PS (bytes per second), or 28.800 bps, 31,
It is not possible to record a 250 bps MIDI signal as is.

In order to solve this problem, the applicant recorded a MIDI signal in the subcode channel of a CD prior to the present invention, and made it possible to reproduce this signal on a CD player to create the original MIDI signal. We have developed a MIDIID post-tuning device and have filed a patent application (Japanese Patent Application No. 1983-294407).

In this way, it is possible to drive an electronic musical instrument by decoding MIDI signals recorded in advance on a digital signal recording medium such as a CD or DAT, but it is possible to drive a synthesizer and a rhythm machine using MIDI signals recorded in the auxiliary recording area of the digital recording medium. When performing automatically, there is a problem that during playback, the period between the performance data and the rhythm may deviate due to operations such as stop or search and the occurrence of uncorrectable errors. In other words, when performing as described above based on MIDI signals, a rhythm start signal starts the rhythm pattern sequence pre-programmed into the rhythm machine, and the sequence proceeds in response to the rhythm clock signal, but the MIDI standard Since it is originally based on the premise that real-time performance information, that is, the time axis is continuous, if you perform fast-forward operations in the middle of a song, the position of the restarted performance data will not match the position of the rhythm pattern. Furthermore, even in normal playback conditions, the rhythm cycle may shift due to increases or decreases in the rhythm clock signal due to scratches on the disc or the like. There was a case.

Therefore, it is an object of the present invention to provide a MIDI signal recording method and apparatus that does not cause a period shift between performance data and rhythm when reproducing MIDI signals.

[Means for Solving the Problems] The present invention has been made to achieve the above object, and when recording a MIDI signal on a digital signal recording medium, a rhythm stop is performed at the beginning timing of each repetition period of a rhythm pattern. , a MIDI signal recording method for recording rhythm start and rhythm clock signals sequentially and continuously.

The present invention also provides a counting means for counting rhythm clock signals based on a rhythm start signal sent from a rhythm machine, and a rhythm stop signal, a rhythm start signal, and a rhythm clock signal when the count value reaches a set value. The present invention provides a MIDI signal recording device that records the generated rhythm signal on a digital signal recording medium, and includes means for sequentially and continuously generating the rhythm signal and resetting the set value.

[Function] The MIDI signal recording/reproducing method and device of the present invention employs the above-mentioned method and has the above-mentioned configuration, so that when the digital signal recording medium is temporarily interrupted and played back by operations such as stop and search, A rhythm signal is generated that allows the rhythm to be played normally even if it is played back from any position, even when an uncorrectable error occurs.

[Embodiments] First, before describing specific embodiments of the present invention, a recording format of a MIDI signal in a subcode channel of a CD will be described.

FIG. 6 is a diagram showing the storage status of data for one pack of subcode channels of a CD, that is, from frame 0 to frame 23. Six bits of data from R to W are stored for each frame, and M
The IDI data is stored from frame 4 to frame 19. Each frame has a 6-bit structure, and the stored MIDI data is in units of bytes, or 8 bits. One byte of MIDI data is, for example, frame 4 R-W 1. : Consists of a total of 8 bits: 6 bits indicated by ao and 2 bits indicated by R and SEa of frame 5. Similarly, frame 5
4-bit bo and R to U of frame 6 in the remaining T-W of
frame 4 to frame 19 in such a manner that 1 byte of data is constructed by a combination of 4 bits b.
12 bytes of MIDI data are stored over 16 frames.

FIG. 5 is a signal waveform diagram of one byte of MIDI data to be finally sent out, and a logical 0 start bit is added to the beginning of the 8-bit MIDI data, and a logical 1 stop bit is added to the end.

FIG. 6 shows the structure of MIDI data in one pack to be sent out. ao'o"o etc. in Figure 6 are the 6th
This shows the correspondence with the data in the subcode in the figure.

To briefly explain the MIDI standard here, MID
I data is sent at a rate of 3125 bytes per second. Also, the subcode in Figure 4 shows one pack consisting of 24 frames, but since 300 packs are played from a CD per second, the MIDI data is played back at 6 bits x 16 frames x 300 backs - 28,800 bps. Ru.

Expressing this in bytes, it is 28,800bps/8-3
8008PS (bite bar second) and MID
This exceeds the I data's 31,258 PS. Therefore, 12 bytes of MIDI per back for all backs.
Storing data is standard according to the MIDI standard. Therefore, as a countermeasure for this, it is necessary to devise measures in advance when recording the subcode of the CD so that 300 packs are 3125 bytes. For example, divide 300 packs into 25 packs of 12 packs, and each group of 12 packs contains up to 11 bytes of MIDI data.
If we assume that there are 7 packs containing up to 10 bytes of MIDI data, the total MIDI bytes of this group will be 125 bytes at most, and the total of 300 packs can be 3125 bytes or less.

However, most of the MIDI data is note-on commands and note-off commands, each of which consists of 3 bytes, so it is better to consider 12 bytes, which is a multiple of 3, as the standard. Therefore, in each group, it is preferable to put 12 bytes into some of the backs and put 11 bytes or less of data into the remaining backs so that the total size is 125 bytes or less.

By the way, CD-MIDI, which stores MIDI data in subcodes of a CD, usually records rhythm clock data on a disc along with various MIDI data when automatically playing a synthesizer and rhythm machine using MIDI.
Rhythm start command FA (hexadecimal number (same below))
The rhythm pattern sequence pre-programmed by the rhythm machine starts at the beginning, and from then on the sequence advances in response to the timing clock command F8. However, if you perform fast-forward operations in the middle of the song, the restart position may change. It no longer matches the position of the rhythm pattern, and even under normal playback conditions, the timing clock may increase or decrease due to scratches on the disc, resulting in a loss of synchronization between the performance data and the rhythm.

That is, FIG. 1 shows M before processing, which is the basic technology of the present invention.
IDI data ((a) in the same figure) and the method of the present invention ((b) in the same figure)
) is shown over time after processing to explain MIDI data. In the figure, the symbols are (1) 903C40;
Note-on command for C4 note (2) 3CGo; Note-off command for C4 note with status omitted due to running status (3) FA; Rhythm start command (4) F8
; Timing clock command (5) FC, Rhythm stop command (6) PG 4803 ; System exclusive frame...P7, C (7) 903E40 ; D Indicates the note-on command for each of the four notes, as shown in Figure (a) For example, in a rhythm pattern that repeats 2 bars in 4 C time, the MIDI standard requires that timing clock F8 be sent 24 times between quarter notes, so 24 x 4 beats x 2 bars - 192 timing clocks will be transmitted.

However, as mentioned above, during the performance, there are fast forwards, stops,
If the performance data is interrupted and restarted due to an error or the like, or if the timing clock increases or decreases due to scratches on the disc, the synchronization between the performance data and the rhythm will be lost, which is undesirable.

Therefore, when recording a MIDI signal in the auxiliary signal recording area of a digital signal recording medium, the present invention provides a rhythm stop and a rhythm stop at the beginning timing of each rhythm pattern repetition period.
By recording the rhythm start and rhythm clock signals sequentially and continuously, the rhythm machine can be started accurately at the beginning of the rhythm pattern repeat cycle even if the performance is interrupted and restarted, and it is possible to prevent MIDI signals from being missed. M that can restore rhythm synchronization even if
Adopts IDI signal recording method.

That is, as shown in (5) of FIG. 1(b), in the method of the present invention, a rhythm stop command FC, a rhythm start command FA, and a timing clock command F8 are sequentially recorded at the beginning of the rhythm repetition period T.

FIG. 2 is a block diagram showing an embodiment of a MIDI signal recording device employing the above-mentioned MIDI signal recording method of the present invention. In the figure, reference numerals 1 and 2 indicate a personal computer and a MIDI control device incorporated therein. The MIDI control device 2 causes a synthesizer 3 and a rhythm machine 4 to perform automatically, and the synthesizer 3 receives performance data from live performance. The rhythm machine 4 is configured to record on the personal computer 1, and furthermore, the rhythm machine 4 is configured to have a desired rhythm pattern programmed in advance and to be started and stopped by operating a start/stop button 41 at the required timing. , these performance information are given to the rhythm signal forming device 5 through MIDI cables 21, 22, 31, and 42.

The rhythm signal forming device 5 is constituted by a normal microcomputer system, converts the 3125 bytes/second serial data received via the cable 42 into parallel (S→P), and temporarily stores it in the reception buffer of the RAM 52. At the same time, a data converter 51 converts the MIDI data to be transmitted from parallel to serial (P-8) and sends it out.
, a CTC (counter timer circuit) 53 that generates a clock as a time standard, a PIO (parallel in/out) 54 that is an interface for receiving human input from keys on a keyboard 55 and driving a display 56, and storing a control program. ROM57 and CPU59
It is equipped with This rhythm signal forming device 5 operates according to the flowchart shown in FIG.
The encoder 6 transfers the data to the CD-ROM shown in FIG.
Bit conversion is performed from 8 bits to 6 bits according to the MIDI recording format, and the rhythm stop, rhythm start, and timing clock commands are sequentially sent at the beginning timing of each repetition period of the rhythm pattern on the CD 7, which serves as the master disk. recorded.

FIG. 3 shows an operation flowchart of the rhythm signal forming device 5. As shown in FIG. That is, first, when the program is started by power-on or reset, each device is initialized and the rhythm start flag is set to 0.

Then, operate the clock setting switch on the keyboard 55 to set the repetition rate of the rhythm pattern, for example, 2 times in 4 C time.
In the rhythm pattern that repeats bars, the number of rhythm clocks F8 is set to 192 and this is stored in the RAM 52. When one byte of input MIDI data is received in this state, that data is moved to the reception buffer, so if you read that data and the rhythm machine 4 has not started, the rhythm start flag is 0, so the data is transferred as is. Send as MIDI output.

When the rhythm machine 4 starts, the rhythm start data FA is obtained, so the rhythm start flag is set to 1, and then when the rhythm clock data F8 is received, the R
The set value stored in AM52 is decremented and rhythm clock data F8 is sent out. Here, when the set value is decremented 192 times, the count value becomes 0.
Therefore, the commands Rhythm Stop FC, Rhythm Start FA, and Rhythm Clock F8 are successively sent out in sequence, and the count value is reset. With this process, after the rhythm start, the rhythm stop FC, rhythm start FA, and rhythm clock F are displayed at the beginning of every two measures.
8 will be inserted as a set. Note that when the rhythm machine 4 is stopped after setting the rhythm start flag to 1, the rhythm stop data FC is received at the MIDI input, so the rhythm start flag is reset to 0, and then the rhythm clock data F8 is received. However, the above-mentioned rhythm command will no longer be generated. When the rhythm machine 4 is stopped, rhythm stop data FC is received, and it is necessary to clear the rhythm start flag and reset the count value based on this data.

Note that FIGS. 1(a) and 1(b) show the above-mentioned processing, in which the MIDI data input to the rhythm signal forming device 5 (FIG. 1(a)) and the MIDI data processed by the rhythm signal forming device 5 and sent out. The MIDI data ((b) in the same figure) is shown over time.

Therefore, according to the above-mentioned embodiment, when a commercially available synthesizer and rhythm machine are made to automatically play from MIDIID- reproduced from a CD subcode, even if the CD player starts playing from an arbitrary position, it is possible to reach the beginning of a measure or the rhythm pattern. The rhythm machine can be started accurately at the beginning of the minimum repetition cycle of
DIID- Rhythm synchronization can be restored even if it is lost.

Furthermore, if the rhythm signal is recorded according to the method of the present invention,
By playing the clock number between the start signals (FA) on the CD player (decoder) side, it is possible to display the rhythm beat number (what beat it is) and the timing of the beginning of the measure, so the instrument Convenient for practice, etc.

[Effects of the Invention] As is clear from the detailed explanation above, in the MIDI signal recording method and device of the present invention, when MIDI-recording is performed on a digital signal recording medium, the MIDI signal is recorded at the beginning timing of each rhythm pattern repetition period. Rhythm stop, rhythm start, and rhythm clock signals are recorded sequentially and continuously, so when automatically playing a synthesizer or rhythm machine, even if you start playback from an arbitrary position, the rhythm will start at the beginning of the rhythm nocturne repetition cycle. The machine can be started accurately, and even if the MIDI ID is lost due to a scratch on the digital signal recording medium, the rhythm synchronization relationship can be restored.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing MIDI data (rhythm signal generation) before processing, which is the basic technology of the present invention, and after processing based on the method of the present invention (rhythm signal generation) over time.
A block diagram showing an embodiment of the DI signal recording device, FIG. 3 is a flowchart showing the processing of the microcomputer that constitutes the rhythm signal forming device 5 section of FIG. 2, and FIG.
A diagram showing one pack of the R-W channel of the D subcode, Figure 5 is a waveform diagram of 1 byte of MIDI ID to be sent, and Figure 6 is a diagram showing the MIDI ID in the 1 byte subcode of Figure 4.
5 is a diagram in which DI data is converted into 12-byte MIDI ID-, and it follows the waveform diagram of FIG. 5. FIG. 4... Rhythm machine, 5... Rhythm signal forming device,
7...CD0 3rd figure figure figure figure

Claims (2)

[Claims] (1) When recording MIDI signals on a digital signal recording medium, a MIDI signal recording method in which rhythm stop, rhythm start, and rhythm clock signals are sequentially and continuously recorded at the leading timing of each rhythm pattern repetition cycle. (2) Counting means that counts rhythm clock signals based on the rhythm start signal sent from the rhythm machine, and when the count value reaches a set value, sequentially outputs the rhythm stop signal, rhythm start signal, and rhythm clock signal. a MIDI signal recording device for recording the generated rhythm signal on a digital signal recording medium, comprising means for generating the rhythm signal and resetting the set value.