JPH02201497A - Digital signal recording and reproducing device - Google Patents

Abstract

PURPOSE:To eliminate the auditory time difference between main data and MIDI data in reproduction by controlling the output transmission timing of a main data reproduction system and a MIDI data reproduction data according to time difference data recorded on a digital signal recording medium. CONSTITUTION:The main data which is recorded in a main signal recording area by imposing EFM demodulation on read data and subordinate code data recorded in an auxiliary signal recording area are D/A-converted through an audio data buffer 6 respectively. The subordinate code data which is passed through a subordinate code data error correcting circuit is bit-converted to demodulate the MIDI data and the time difference data between the main data and MIDI signal is obtained to control the read delay quantity between an audio data buffer 6 and a MIDI data buffer 10. The demodulated MIDI data is received through the MIDI data is received through the MIDI data buffer 10 and a MIDI output is sent out. Consequently, the auditory time difference between the main data and MIDI data in reproduction is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to recording and reproducing digital signals, and particularly to a MIDI signal processing device for controlling an electronic musical instrument.

[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. that comply with this MIDI standard have already been put into practical use, 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. 148470. 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. The transmission rate is also 3,600BPS (byte bar second), that is, 2g, 800bps, 31,
250 bps MIDI ID - cannot be recorded as is.

Furthermore, when MIDIID is given to a sound source such as an electronic musical instrument, the time required from when the sound source receives MIDIID until the actual sound is produced varies depending on the manufacturer and model of electronic musical instruments such as synthesizers. Although there is not much of a difference, for example, MIDIID has commercialized grand pianos that can perform automatically.
DIID - How long does it take from inputting this signal to decoding the signal, transmitting the control content to the piano's mechanical part, and for this mechanical part to actually move the piano's hammers and strike the strings, causing the strings to vibrate and produce sound? Approximately 0.5 seconds are required. Therefore, the time interval between the CD audio signal playback sound and the sound generated by the instrument during automatic performance by MIDI ID is about 0.5 seconds apart, which creates a sense of discomfort when listening to both sounds at the same time. There is also a problem in that it causes problems when giving lessons through musical performances.

Furthermore, a device that records on a CD together with a MIDIID-digital audio signal with a predetermined time difference is disclosed in Japanese Patent Laid-Open No. 63-3.
This method was proposed in Japanese Patent Application No. 0900, but recording was performed with a fixed time difference, and it did not take into account deviations in performance timing of individual musical instruments.

Therefore, the present invention can record a MIDI ID on a subcontract channel of a digital signal recording medium such as a CD or DAT, and reproduce it to create the original MIDI ID. Te MIDII
It is an object of the present invention to provide a digital signal recording and reproducing device which can set a time difference with a D-audio signal and can eliminate an auditory time difference by controlling the output timing of each signal during reproduction.

[Means for Solving the Problems] The present invention has been made to achieve the above object, and the digital signal recording/reproducing device according to the present invention stores the main data and the MID data together with the MIDI data in the auxiliary signal recording area.
demodulating means for reading a signal from a digital signal recording medium on which time difference data of I data is recorded and performing EFM1n modulation; and control means for controlling output sending timing of a main data reproduction system and/or a MIDI data reproduction system based on the time difference data. It is characterized by having the following.

[Function] Since the digital signal recording and reproducing apparatus of the present invention is configured as described above, during demodulation, the main data reproducing system and/or MIDI The output sending timing of the data reproduction system is controlled, and the audible time difference during reproduction of main data and MIDI data is eliminated.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the digital signal recording/reproducing apparatus of the present invention. The signal recording and reproducing device includes an optical pickup 2 that reads CD data from a CDI as a digital recording and reproducing medium, amplifies and inputs the read data through a photodetector preamplifier 3, demodulates it using EFM, and records it in the main signal recording area. The audio data as the main data and the subcode data recorded in the auxiliary signal recording area are corrected for audio data errors, and the output of the interpolation circuit 5 is converted into digital/analog CD/A) audio data via the audio data buffer 6. The D/A conversion circuit 7 outputs the subcode data through the subcode data error correction circuit 8, and the subcode data is bit-converted to demodulate the MIDI data, and the time difference data between the audio data and the MIDI signal is obtained to convert the audio data into the audio data. It has a subcode signal processing circuit 9 that controls the amount of read delay of the buffer 6 and the MIDI data buffer 10, and a MIDI modulation circuit 11 that receives demodulated MIDI data via the MIDI data buffer 9 and sends out a MIDI output. .

The MIDI output is converted to audio output via the MIDI instrument 12 and input to the audio mixer 13 together with the audio output via the D/A conversion circuit 7, and then outputted from the speaker 15 via the audio amplifier 14.

FIG. 2 is a diagram showing the storage status of data for one back of the CD subcode channel, that is, from frame O to frame 23. 6-bit data from R to W is stored for each frame, and 0, 1'' in the sub-item section, which is indicated by 2 bits in R and S in the instruction section shown in frame 1, is CD-MID.
The data content for instrument settings in I indicates that there is time difference data in frames 18 and 19.

Note that when "0.0#" is included in this sub-item section, it is the original MIDI data area (frames 4 to 19).
contains MIDI data and does not record time difference data. Each frame has a 6-bit structure, and the MIDI data stored as described above is in units of bytes, that is, 8 bits. One byte of MIDI data consists of, for example, 6 bits indicated by ao in R-W of frame 4 and 2 bits a' in R and S of frame 5, for a total of 8 bits. Similarly, 4 is applied to the remaining T to W of frame 5.
bit bo and 4 bit b' in R-U of frame 6
12 bytes of MIDI data are stored over 16 frames from frame 4 to frame 19 in such a manner that 1 byte of data is configured by the combination of .

In Fig. 2, the sub-item part is "0.1°" and 12-bit time difference data is recorded in frames 18 and 19, and the M I D of frames 4 to 11 is
The I signal will be ignored.

The time difference value is expressed in two's complement, and 1 bit is 320
Since it represents the time interval of μSee, the setting range is -(2'X320X10-8)see ~ + ((2
1) x320xlo-6) See --655,
36m5~+655.04m5. At this time, if the first bit is, for example, 10, it indicates a delay time difference between audio data and MIDI data (-, the opposite is true). The next back MIDI data is controlled based on this time difference data.

Note that when writing track numbers and index numbers in frames 4 to 6, the corresponding MIDI data is controlled based on time difference data.

To explain a specific example here, if MIDI data is entered 065 seconds earlier than audio data, the setting value is 0.5 + (320X10 =) - 1563, so if this is expressed in binary, frame 18 -011000 frame 19-011011.

Here, since 320 μsec is the MIDI transfer byte rate, this delay amount is equivalent to setting the number of MIDI byte clocks, and if set in this way, the M
This has the advantage that data delay processing for sending IDI data can be easily performed. However, in the case of audio delay, the audio clock frequency Fs is 44.1kl
lz and the MIDI byte rate is 1/320
Since it is u -3,125kllz, an asynchronous buffer memory is required.

However, in a normal CD-MIDI system, MIDI is recorded in advance, and audio delays are often not included to reduce costs, so the rate is set to match the rate of MIDI. . In other words, the delay of the audio playback system is approximately constant, and the delay of the instrument side is larger, and F s is 44.1kHz,
The buffer memory required to delay 16-bit, 2-channel CD audio data by the maximum delay time difference of 855.36a+sec is 0.65536 x 44. lX
103x 2 x 164924.844 bits; tt
A capacity of s, e Kbytes is required. Therefore, since MIDI usually takes precedence, the time difference data can be displayed as a positive value, and the audio data buffer 6 can be omitted in the configuration shown in FIG.

FIG. 3 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. 4 shows the structure of MIDI data in one pack to be sent out. ao, ao, b in Figure 4
o etc. indicate the correspondence with the data in the subcode of FIG. To briefly explain the MIDI standard, MIDI data is transmitted at a rate of 3125 bytes per second. Also, the subcode in Figure 2 shows one batch consisting of 24 frames, but from a CD, it is 300 frames per second.
Since the back is played back, the MIDI data is 6 bits x
It is played back at 16 frames x 300 packs - 28,800 bps. Expressing this in bytes, it is 28,800 bps/
8-3600 BPS and MIDI data is 3125
It exceeds 8PS (bites per second).

Therefore, it is beyond the MIDI standard to store 12 bytes of MIDI data for each back for all backs.

Therefore, as a countermeasure for this, it is necessary to devise measures in advance when recording the subcode of the CD so that 300 bucks equals 3125 bytes. For example, 300 bucks is 1
Divide into 25 packs into 2 packs, and if each group of 12 bags contains 5 packs containing up to 11 bytes of MIDI data, and 7 packs each contains up to 10 bytes of MIDI data, the MIDI data of this group The total number of bytes is up to 125 bytes, and 3 for the entire 300 packs.
It can be 125 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.

FIG. 5 is a diagram showing a processing flow by the CPU of the subcode data error correction circuit 8 and subcode signal processing circuit 9 of FIG. 1. Here, the subcode data error correction circuit 8 may be the same as that used in a known CD graphics decoder, and includes parity bits ip-p3 for frames 20 to 23 and parity bits ip-p3 for frames 2 and 3. This decoder has many common parts with conventional CD graphics decoders, so it is compatible with both CD graphics and MIDI.
It can also be a signal recording/reproducing device, and error detection can be realized by software as well as hardware. When used as a CD graphics decoder in this way, it is necessary to identify whether the data contained in frame 1 and frames 4 to 19 in FIG. 2 are graphics data or MIDI data. The 3 bits indicating the mode in frame O in Figure 2 are used for this purpose, and are 001 for graphics and 011 for MIDI.Similarly, the last 3 bits of frame 0 are items, indicating the type of graphics, etc. This shows that.

In addition, if the item contains MIDI data, the item will be 0.
It is 00.

That is, in the first judgment step in FIG.
3. When ITEM-0, it is detected that it is in MIDI mode, and in the next judgment step, when the sub-item of frame 1 in Fig. 2 is "01", the time difference data is in frame 18.19, and the time difference data is "00#". When the MIDI data is stored, it is detected that the sub-item is 01'', that is, 1.
At this time, the time difference data is set and is set to “00” again.
That is, when it is 0, 6 bits of MIDI data = 8. Bit conversion processing and MIDI data transmission processing to the internal buffer are performed, and in this way all data in the pack is converted, and the MIDI byte is converted into a 10-bit serial format with a start bit and a stop bit added. M.I.
It is sent as a DI signal.

FIG. 6 shows a processing sequence when interrupt processing is performed by the CPU and MIDI data buffer 10 of the subcode signal processing circuit 9 of FIG. 1, and in the figure, RAM indicates the data buffer 10. IRT is an interrupt clock for MIDI transmission, and is input at 3.125 kllz, and interrupt processing is executed at regular intervals. T is the time difference data in the format, and CTL-5W is a setting switch on the hardware to set whether or not to perform time correction.For example, when playing a grand piano, set it to 0FFS [when connecting a child instrument, etc. When you want to eliminate the output time difference, turn it on, and use several types of setting switches to make more detailed timing settings depending on the output time difference for each electronic musical instrument. DF indicates a delay flag, and when DF-1, delay control is performed based on time difference data. In other words, the contents of the internal buffer are written to the RAM (corresponding to MIDI data buffer 10 in Figure 1). Let MA' be ((MA' - T)MOD
40961, that is, the process of reading data in the RAM from one hour ago is executed. And that data is data F
F n, that is, in the case of idle feed data, MA' - (MA'
+1) MOD40'96, that is, advance the address by one and return. If it is not the above-mentioned idle data, the MIDI data is converted into the above-mentioned serial data and sent. In addition, when there is no time difference data or when there is no setting switch setting, the data is read from the internal buffer, and if the data is jump data, it returns, and if it is not jump data, the MIDI data is converted to serial data as described above. Convert and send. After sending, if time difference data is set, the address -((M A '-T) MOD409
Return the data of 6) as blank feed data FFH,
If time difference data is not set, change the address to MA.
' - (MA' 11) One by MOD4096,
Advance and return. In this way, the output timing of the MIDI signal relative to the audio signal is controlled.

FIG. 7 shows a more detailed processing sequence after the bit conversion process shown in FIG. The subcode back part in Figure 2 is the 4th
This figure shows a processing flow for converting MIDI data of up to 12 bytes.

In Figure 7, BYTES is n3 shown in the frame of Figure 2.
~nO value, which means that data in the MIDI data area that does not contain data within one bag is set to “FF”.
This means a system reset in MIDI, but since it is unlikely to be stored on a disc that is not normally used, this value is used as data for skipping.

Also, FA is the frame address of the subcode, MA is the address of the memory that stores MiDI data, and MB is the M
Indicates the byte number of IDI data, or n is (FA-4)
is divided by 4. Please note that the first judgment step is BY
TES-07 detects the presence of one or more MID I Hyde, and (FA-4) MO of the next judgment step.
D4? is the step of calculating the remainder when (FA-4) is divided by 4, and the following flow is determined depending on whether the remainder is between 0 and 3. This flow converts one pack, that is, frame 4 to frame 19 in Figure 2, and converts the 12-byte M
II) I data is created and then similar processing is performed for the fire pack.

The maximum 12 bytes of MIDI data created in this way is sent to the buffer 10 in Figure 1, P/S converted and bits added in synchronization with the MIDI sending clock, and the
The DI byte is a serial MID of 10 bits with a start bit and stop bit added as shown in Figure 3.
It becomes an I signal and is sent to the outside. In this case too, MIDI
It is sent out in synchronization with the sending clock.

Therefore, according to the above embodiment, the time difference between the audio data recorded on a CD and the MIDI data at the time of reproduction is not fixed, but the time difference is set with a degree of freedom in setting the time difference within a predetermined range. data in the CD subcode area,
This data is recorded in a separate area from the MIDI data, and when this disc is played back, the time difference data is played back, and based on this value, the perceived time difference between the audio playback sound and the MIDI instrument performance sound is corrected. It is possible to automatically [E] the timing so as to eliminate the problem. Further, the present invention enables the following.

(2) Since the time difference between audio and MIDI is recorded as a numerical value on the CD disc, the time difference can be set arbitrarily depending on the connected musical instrument.

2) It is possible to provide a decoder that can automatically correct and output a fixed time difference corresponding to the connected musical instrument regardless of the time difference when the time difference varies from song to song or from disc to disc.

3) It can handle both advance and delay of the time difference between audio and MIDI.

4) Contrary to 2) above, it is also possible to change the time difference setting for each song or for each audio. For example, on a grand piano, the lower the pitch, the longer the actual sound will be heard after the note-on is input. Since it takes a long time for the sound to appear, it may be necessary to change the amount of delay for each pitch. In this case, you can achieve this by putting the setting data in a back that precedes the back that contains the note-on information of the sound for which you want to change the time difference setting.

In the above embodiment, the time difference data was recorded in a sub-item of the CD format, but it may be recorded in any format in the sub-code area of the CD as long as it does not affect MIDI data reproduction.

Alternatively, the time difference data may be recorded using a MIDI data small data item exclusive without providing sub-items. At this time, S ub −1ten in FIG.
? The 1 part of the branch disappears, and MIDI6blt → 8
After the bit ID, the system exclusive message is decoded and time difference data is set.

In addition, in the above embodiment, since real-time performance is important for MIDI data, it must be recorded in the CD subcode with priority over other data (for example, graphics data), and in such a case, MIDI data encode and put it in the back, and then use the leftover back to put the graphics data. However, among the graphics data, there is data that you want to put in consecutive backs, or data that has to be put in consecutive backs due to the standard. There is data that cannot be used. For example, CD graphics PRESET M
The instruction EMORY consists of 16 consecutive
When writing this instruction to the disk, as mentioned above, you must first put it in the MI
After inputting DI data, there is a possibility that there is no space left to input 16 consecutive backs. In such a case, the above problem can be solved by using the time difference data, moving the MIDI back that is already in the place where you want to insert 16 consecutive backs, and inserting the time difference data corresponding to the movement. Ru.

Furthermore, in addition to the above embodiments, the present invention also provides, for example, MIDI
When creating musical scores on a computer etc. based on data,
It is also possible to provide a system that allows you to play along with the audio by controlling the display so that it is displayed at the same time as the audio, or by expanding the time difference setting range and displaying the score on a CRT etc. a few seconds before the audio appears. . At this time, take into consideration the time required for data processing and display on the computer, and
It is possible to control the output timing of DI and audio. In order to expand the setting range of the time difference, the number of bits (12 bits) of the time difference data shown in Fig. 2 can be increased, or the resolution per bit can be increased to 321μ.
sec (for example, if it is multiplied by 10 and becomes 1 bit - 3.2 m5 ec, it can be handled by enlarging it to about 6.55 seconds).

Further, as the recording medium, in addition to CDs, any medium having both main information and sub-information areas can be applied.

In the embodiment described above, MIDI signals were recorded on a CD and then played back, but the present invention has the following features.

It can be applied not only to CDs but also to cases in which data is recorded in advance on a digital signal recording medium such as DAT and then reproduced.

FIG. 8 shows an embodiment in which MIDI signals are recorded on DAT. In FIG. 8, (a) shows a generally known DAT frame format, and (b) shows one subcode area of one track in the frame format.
e) indicates the format within the block in (b), BAEvel indicates the format within the even address, and BAEvel indicates the format within the even address.
AOdd indicates a format within an odd address, and all of these are well known.

Furthermore, Format (I), (I
I) is a diagram showing how MIDI signals are recorded in the back format of DAT, and in the diagram ITEM and PARIT are
Part Y is known.

The value of ITEM is the current DAT format (1987
One of the numbers 1000 to 1110, for example 1000, which are undefined in the DAT Conference (published in July 2013), is used as the MIDI mode. SUBITEM (1) identifies the contents of 82 to B7 in more detail in the MIDI mode, and is set to 0000, for example, when MIDI data is to be input.

ADRS is 00000 (0) to 10010 (18)
19 addresses, which represent the position of MIDI data within one frame. Here, 1 bag contains 5 bytes, so 1 frame contains 5 bytes x 19 (address) - 95 bytes of MIDI data, and 1 frame is 30 m5ec as is well known, so If this happens, the number of MIDI data that can be input per second will exceed the maximum transfer capacity of MIDI.

Therefore, as in the case of CDs, it is necessary to limit the amount of recorded MIDI data.

FIG. 8(e) shows a case in which this restriction is applied, so that 375 bytes of MIDI data can be stored in four frames. DAT is 1 sec per second as mentioned above.
/ 30 wsec frame, so -3,125
(K bytes/second), which is consistent with the MIDI standard.

The actual data at this time is the first three frames, frame addresses -4n to 4, with the four frames as one unit.
At n+2, 94 bytes of MIDI data are input, and at the last frame, that is, frame address -40+3, 93 bytes of MIDI data are input, resulting in a total of 94X3+93-375 bytes.

Also, in each frame, addresses 0 to 18 are assumed to contain 5 bytes of MIDI data for addresses O to 17 in one unit of the four frames, and for address 18, frame addresses -4n to 4n+2
When the frame address is -4n+3, 4 bytes of data are entered, and when the frame address is -4n+3, 3 bytes of data are entered. Furthermore, during playback, MIDI data is output after being expanded on the time axis.

Furthermore, ForIlat(II) in FIG. 8(d) is set to 1 in order to reduce the number of packs required for MIDI.
A pack containing 6 bytes of MIDI data.
The meaning of DRS is the same as Format (I).

At this time, ADRS contains 0 to 15 (0000 to 111).
1) data is given, and in order to satisfy the MIDI transfer rate, 94 bytes of MIDI data is placed in frame addresses 4n to 4n+2 and 95 bytes of MIDI data is placed in frame address 4n+3, as in ForIlat (1). The last address in each frame, i.e. address 1
5 contains 4 bytes of data for frame addresses -4n to 4n+2, and 3 bytes of data for frame address -40+3.

Format (I) in the figure shows the first plan.

Here, using 4 bits of SUB ITEM, for example, when SUB ITEM'-0000, MIDI
Record the data on B3-7, 5UBITE￥-0001
You may also include time difference data. At this time, ADRS
always records 17 packs of 0 to 1.6 in one frame, extends this to 17 frames 0, and outputs MIDI data.

In the same figure, in format (I!), SUB ITE
M.

Instead of having BYTES, 1 pack has 6 bytes of M.
I DI Input I data. At this time, ADR5 is 0
16 backs of ~15 are always put in one frame, and when playing back, like Format (I), it is expanded on the time axis and M
Output IDI data.

Since the audio data is output after one frame due to error correction, etc., all the MIDI data need only be error-corrected within this one frame and prepared for addresses 0 to 15.

At this time, since there is no BYTES, the part that does not contain MIDI data is the system reset FF, which is never used in such a system.

Put in. Error correction is performed using back C1 (see FIG. 6).

Furthermore, since there is no SUB ITEM, time difference data must be recorded in MIDI data by preparing a separate ITEM number or by using a MIDI system exclusive message.

[Effects of the Invention] As is clear from the detailed explanation above, in the digital signal recording and reproducing apparatus of the present invention, the main data reproducing system and the MIDI data reproducing system are controlled based on the time difference data recorded on the digital signal recording medium. Since the output sending timing is controlled, it is possible to eliminate the perceptual time difference between the main data and the MIDI data during playback.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the digital signal recording/reproducing apparatus of the present invention, and FIG. 2 is a subcode R-W of a CD.
Figure 3 shows the waveform of 1 byte of the MIDI signal to be sent. Figure 4 shows the MIDI data in the subcode of 1 batch in Figure 2 as a 12-byte MIDI signal. , a diagram according to the waveform diagram of FIG. 3, FIG. 5 is a flowchart showing the processing of the microcomputer configuring the subcode data error correction circuit and subcode signal processing circuit of FIG. 1, and FIG. FIG. 7 is a detailed flowchart after the bit conversion process shown in FIG. It is a figure which shows an example. 1...CD, 4...PLLEFM demodulation circuit, 6...
- Audio data buffer, 8... Subcode data error correction circuit, 9... Subcode signal processing circuit, 1
0...MIDI data buffer. Inventor of the 7th drawing

Claims (1)

[Claims] demodulation means for reading and EFM demodulating a signal from a digital signal recording medium in which time difference data between main data and the MIDI data is recorded together with MIDI data in an auxiliary signal recording area; and a main data reproducing system and/or MIDI data based on the time difference data. A digital signal recording and reproducing device comprising: a control means for controlling output transmission timing of a reproducing system.