JPH06348259A - Midi editing device - Google Patents

Abstract

PURPOSE:To obtain the editing device which facilitates data conversion when generating sub-code data of a CD by obtaining MIDI data from a file wherein a MIDI sequence is recorded. CONSTITUTION:While a standard MIDI file 1 generated at a MIDI signal reproduction part 2 is reproduced by the same MIDI sequencer and the tempo map is made constant by the MIDI sequencer of a MIDI signal recording part 3, MIDI data are resampled. Then when the rate of the tempo map to be made constant is set equal to the rate of the pack of the CD (rational multiple of pack rate), the MIDI data can be converted into a pack file as it is and the data conversion is facilitated. Further, while the both are synchronized with each other by using SMPTE time codes used by the MIDI sequencer of the MIDI signal reproduction part 2 or MIDI signal recording part 2, the MIDI data are resampled to make the tempo map, which irregularly varies, constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a MIDI for recording MIDI data in a subcode area of a digital signal recording medium.
Regarding the editing device.

[0002]

2. Description of the Related Art Normally, the audio master of a CD is P
It is brought into a CD mastering process in a form recorded on a magnetic tape for VTR, MO (magneto-optical disk), HD (hard disk), etc. using a CM processor. On the other hand, the standard MIDI file format for MIDI data is most common. Therefore, in order to perform CD + MIDI authoring (editing work for creating a disc), it is most convenient to convert a standard MIDI file into a CD subcode file which is developed into an image on the time axis.

In addition, file-to-file (file T
o file) format, information that is not on the MIDI line, that is, a multiple-write message specified in the CD + MIDI operation standard set by the EIAJ (Japan Electronic Machinery Manufacturers Association) or a substitute message that uses an all-note-off message ( Offline processing such as addition of (status information) is possible, but conventionally, these processings could not be performed because MIDI had to be converted into subcodes in real time.

Here, the CD subcode file developed on the time information is a file of a format in which actual subcode data is sequentially filled from the pack at the beginning of the music. Since the actual subcode of a CD is 6 bits,
The upper 2 bits are filled with 00 and are represented by 8 bits. By doing this, when cutting the CD, while writing the audio data to the main data area of the CD, at the same time, one byte for each frame of the CD from the subcode file (ignoring the upper 2 bits), the packed data is sequentially. In a karaoke apparatus using CD graphics, which can be written as a subcode on a CD and which has been sold in the market, a disc is cut by this method.

Incidentally, the MIDI sequencer expands MIDI sequence information described in a file format on a recording medium such as a floppy disk, a CD-ROM, an IC card, etc. on a time axis, and is in the form of application software of a personal computer. Some are realized by dedicated hardware. Usually, these files are called sequence files and are described in a format unique to each sequencer.

The standard M format is a format that allows this file to be read and written by any sequencer.
In recent years, the number of sequencers compatible with this format for IDI files has increased. Also, this standard MI
In the DI file, the MIDI message occurrence time is usually based on the number of beats, and the MIDI message that should occur at that time.
It is designed to be described with the message. The fact that the number of beats is the basis requires tempo information when developing this on the time axis. Without this, the sequencer side cannot know how fast the performance information should be expanded on the time axis.

The tempo information is described on a standard MIDI file, and is expressed in the form of microseconds for each quarter note. Therefore, if the tempo is defined in the finest manner, the tempo will change for each quarter note. In this description, the tempo information has a resolution of a microsecond unit, and therefore, a quarter note has an error of maximum plus or minus 0.5 microsecond. For example, if the length of one song is 5 minutes, and one quarter note per beat, and the tempo is the usual 120 beats / minute (two quarter notes per second), then a total of four quarters per song The number of notes is 5 x 120 = 600. Therefore, as described above, in a song whose tempo changes for each quarter note, there is a maximum error of about 0.5 x 600 = 300 microseconds in real time.

By the way, in CD + MIDI, audio tracks and MIDI tracks (to be precise, musical sound sounds obtained by reproducing MIDI data written on MIDI tracks and supplying them to a MIDI sound source) are accurately recorded from the beginning to the end of the song. It is necessary to synchronize, but in human hearing, the time difference between the sounds generated by the two sound sources is about 10 milliseconds or less unless the sounds are detected by the position difference (ie, sound localization) by both ears. Is unrecognizable, the resolution of the file format itself is audibly no problem.

[0009]

However, the actual sequencer does not create the tempo map with such accuracy. For example, in a sequencer, the minimum resolution of tempo on the time axis is 500 μsec (0.5 msec), and
Since the resolution on the time axis that can be processed is different depending on the sequencer used, when a standard MIDI file created by a certain sequencer A is read by another sequencer B, the sequencer A and B can accurately read the last one note of one song. The playing time of does not always end at the same timing.

Naturally, this is because the clock used for timing generation is also different, and the processing calculation method after reading the tempo data from the standard MIDI file differs depending on the sequencer. In addition, the tempo data on the standard MIDI file is not changed stepwise for each quarter note, but has a function of changing the tempo linearly or curvedly on the time axis more finely than the quarter note. There is also a sequencer. In this case,
Since the rate of change differs depending on the sequencer, it is impossible to match each MIDI message described in the file with the correct time position.

Even if the error is set to fall within a certain range, the minimum time-axis resolution is different for each sequencer. Therefore, in the CD + MIDI authoring tool, the standard MIDI file is prepared for each sequencer. A processing sequence has to be created. However, the existing MIDI sequencer is PDS.
Considering compatible PCs from (Public Domain Soft) to professional tools, there are many applications, and it is difficult to support all of these sequencers, and even if it is possible, the software becomes complicated. ,
Editing work becomes complicated.

On the other hand, with CD + MIDI, MIDI data is recorded in pack units. Packs are recorded on the CD at a rate of 300 packs per second. Therefore, when converting the MIDI sequencer file described in the standard MIDI file into subcodes, the time is accurately expanded in microsecond units for each beat from each piece of tempo information and these are expanded. It must be converted into pack data again by dividing it at the pack recording rate, that is, every 300 Hz (3.33333 msec). In addition, in the conventional example,
Information not on the MIDI line, namely EIAJ
It is not possible to perform processing such as the addition of a multiple-write message specified in the CD + MIDI operation standard defined in 1. and a substitute message (status information) using an all note off message.

The present invention has been made in view of the above-mentioned points, and the MID from the file in which the MIDI sequence is recorded is recorded.
An object of the present invention is to obtain a MIDI editing device that can facilitate data conversion when obtaining I data and creating subcode data of a CD.

[0014]

According to a first aspect of the present invention, there is provided a MIDI editing apparatus for reproducing a MIDI signal from a file recorded with a MIDI sequence, and a MIDI signal reproducing means for reproducing the MIDI signal from a file of a digital signal recording medium. MIDI signal recording means for re-sampling and recording at a tempo that is a rational multiple of the code recording rate.

Further, the MIDI editing apparatus according to a second aspect uses the time information such as a time code when performing the sampling, and the MIDI signal reproducing means and the MIDI signal reproducing means.
It has means for synchronizing with the DI signal recording means.

[0016]

In the MIDI editing device according to claim 1,
The MIDI signal reproduced from the file in which the MIDI sequence is recorded by the MIDI signal reproducing means is set to MID
The I signal recording means performs resampling in advance at a tempo that is a rational number multiple of the recording rate of the subcode of the digital signal recording medium to facilitate data conversion when creating subcode data of the digital signal recording medium.

Further, in the MIDI editing apparatus according to the second aspect, when performing the sampling, the MIDI signal reproducing means and the MIDI signal are reproduced by using a time code or the like.
By synchronizing with the signal recording means, synchronization deviation during re-sampling can be prevented.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to CD + MIDI will be described below with reference to the drawings. First Embodiment FIG. 1 is a block diagram showing the MIDI editing apparatus according to the first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes MIDI which will be described later.
A standard MIDI file created by a MIDI sequencer serving as a signal reproducing unit, in which MIDI data to be recorded in a subcode of a CD is stored. A MIDI signal reproducing section 2 which is the same as or compatible with the standard MIDI file 1 created and which is a MIDI sequencer reproduces the standard MIDI file 1 and outputs it as a MIDI signal.

A MID consisting of a MIDI sequencer
The I signal recording section 3 records the MIDI signal reproduced by the MIDI signal reproducing section 2. Reference numeral 4 denotes a standard MIDI file conversion unit (hereinafter, the standard MIDI file conversion unit is referred to as an SMF conversion unit) that converts the MIDI data recorded by the MIDI signal recording unit 3 into a standard MIDI file (SMF) 1 and stores the standard MIDI file (SMF) 1. Reference numeral 5 is a subcode conversion unit for converting the standard MIDI file created by the SMF conversion unit 4 into a CD subcode file, and 6 is a CD cutting device for cutting a CD + MIDI disc. The standard MI
The DI file 1 and the SMF conversion unit 4 can be implemented without using the standard MIDI file format.

Next, the operation of the configuration shown in FIG. 1 will be described. In the configuration of FIG. 1, M of the MIDI signal reproducing unit 2
Since the standard MIDI file 1 created by the IDI sequencer always has the same timing as long as it is played back by the MIDI sequencer, it is played back at the timing intended by the creator. Then, the MIDI data reproduced by the MIDI sequencer of the MIDI signal reproducing section 2 is converted into MI
The MIDI sequencer of the DI signal recording unit 3 resamples the MIDI data while keeping the tempo map constant. Here, in the MIDI sequencer of the MIDI signal recording unit 3 for resampling the MIDI data, if the constant tempo map rate is set by the method described below, the MIDI data on the standard MIDI file 1 is directly stored in the pack file. Can be converted to.

If a standard MIDI file is recorded at a resolution of 480 ticks per beat, the CD pack cycle is 300 (packs / second), so if the tempo is 37.5 beats per minute, 480 (Tick / quart
er-note) × 37.5 (quarter-note / minute) = 300 (pack / second)
× 60 (seconds / minute) becomes 1 tick per pack (q
uarter-note: quarter note). Therefore, the standard MI
It is sufficient to convert to pack data for each tick in the DI file 1. By doing so, data conversion can be performed easily, and at the same time, the start position of each MIDI message on the standard MIDI file 1 coincides with the start position of each pack. Can be reduced.

That is, in the standard MIDI file, normally, a completed MIDI message is described in the file for each tick. Therefore, by always writing the completed MIDI message in the pack unit in the pack, the CD + MIDI operation is performed. It is possible to comply with the MIDI message completion rule in the pack determined by the standard. Further, in the CD + MIDI operation standard, there are cases where the message is not completed within the pack, such as a system exclusive message, but since the frequency of occurrence is low, it can be handled by exception processing.

As described above, the MIDI signal recording section 3
The MIDI data recorded by the SMF conversion unit 4 is converted into a standard MIDI file and stored in a recording medium. The standard MIDI file created by the SMF conversion unit 4 is converted into a CD subcode by the subcode conversion unit 5. And C by the CD cutting device 6
The D + MIDI disc is cut.

In the above description, the pack rate and the tempo map rate are one-to-one, but it is also conceivable to resample at a tempo that is a rational multiple of the pack rate. This is because standard MIDI software is used with sequence software such as a MIDI sequencer.
If there are many MIDI messages that should be generated at the same timing on the file, even if they are described at the same timing, a time delay may occur during transmission due to the processing time on the MIDI sound source side and the serial transmission of MIDI signals. There is a possibility that this may cause a so-called musical “morrow” due to a time lag, so the order of MIDI messages that occur at the same timing may be changed by first transmitting a message related to pronunciation. Sometimes.

At the time of re-sampling, a plurality of timings are re-sampled to one timing, so that the order is wrong, an originally unintended performance is performed, and in the worst case, the MIDI standard is violated. The data may be arranged in such a way that it will be lost. In order to prevent such a situation, it is necessary to increase the resample rate as much as possible so that a plurality of timings are not resampled into one timing. In such a case, by performing the resampling at a tempo that is a rational number multiple of the pack rate, it is possible to prevent the synchronization deviation while solving the above problems.

Second, Third, and Fourth Embodiments FIGS. 2 to 4 show the second to fourth embodiments, respectively, and show the respective embodiments in the case of synchronizing with a time code at the time of re-sampling. Particularly, at the time of re-sampling, if audio data and MIDI data are already in a synchronized state, synchronization is applied in this way in order to prevent loss of synchronization due to re-sampling. On the contrary, when the sound source is sounded by the resampled MIDI data and the audio signal is newly recorded, the time code synchronization need not be applied as shown in FIG.

In the second embodiment shown in FIG. 2, the MID
SM used in the MIDI sequencer of the I signal recording unit 3
PTE (Society of Motion Picture and Television E)
ngineers) The MI signal reproduced by the MIDI signal reproducing unit 2 while being synchronized with the MIDI signal reproducing unit 2 by the time code.
By resampling the DI data with the MIDI signal recording unit 3 keeping the tempo map constant, the irregularly changing tempo map can be made constant.

Similarly, in the third embodiment shown in FIG. 3, the MIDI signal reproducing unit 2 is synchronized with the MIDI signal recording unit 3 by the SMPTE time code used in the MIDI sequencer of the MIDI signal reproducing unit 2. By re-sampling the MIDI data reproduced in 2 while the MIDI signal recording unit 3 keeps the tempo map constant, the irregularly changing tempo map can be made constant.

Further, in the fourth embodiment shown in FIG. 4, an SMPTE time code generator 7 for generating an SMPTE time code is provided, and a MIDI signal is reproduced based on the SMPTE time code generated by the SMPTE time code generator 7. The M signal reproduced by the MIDI signal reproducing unit 2 in a state where the unit 2 and the MIDI signal recording unit 3 are synchronized.
By resampling the MIDI data of the IDI data while the tempo map is kept constant in the MIDI signal recording section 3, the tempo map that changes irregularly can be made constant.

In each of the above-described embodiments, the standard MIDI file 1 created by the MIDI sequencer of the MIDI signal reproducing section 2 always has the same timing as long as it is reproduced by a sequencer having file compatibility or the MIDI sequencer. Therefore, it is played back at the timing intended by the creator. Therefore, the two MIDI sequencers, the MIDI signal reproducing unit 2 and the MIDI signal recording unit 3, are used, and the S used in the MIDI sequencer is wholly used.
While synchronized with MPTE time code, one of the M
The MIDI data reproduced by the IDI sequencer (MIDI signal reproducing unit 2) is converted to the other MIDI sequencer (MID
With the tempo map fixed in the I signal recording section 3), M
By resampling the IDI data, the tempo map that changes irregularly can be made constant.

The above-described contents are to use the existing MIDI sequencer as it is, convert it to a MIDI signal and then resample. However, this requires two sequencers (personal computers) in the re-sampling step of the editing process, and is also a complicated task. Therefore, in order to eliminate this step, a soft resample that automatically expands to the time axis at the time of subcode conversion can be considered. This is to convert once on the time axis based on the Ticks and tempo information of the standard MIDI file described above, and then convert to the time axis of the pack based on this. That is, as shown in the example of the soft resampling in FIG. 5, each MIDI event is once converted on the time axis based on its tempo and the delta time that is the time interval information of the event occurrence, and the time axis of the pack is further converted. By converting to, the automatic expansion to the time axis at the time of subcode conversion by soft resampling is performed. It should be noted that the MIDI code is not limited to the CD, but may be added to the subcode area of another digital recording medium such as a DAT or a digital VTR.
It is also possible to record the signal in the manner described above in the discussion. Further, although the Tick rate is set to be the same as the pack rate in the present embodiment, the same effect can be obtained even if the pack rate is rational multiple.

[0032]

As described above, according to the present invention as set forth in claim 1, the MID is reproduced by the MIDI signal reproducing means.
MID reproduced from the file recording the I sequence
Since the I signal is resampled by the MIDI signal recording means in advance at a tempo that is a rational multiple of the recording rate of the subcode of the digital recording medium, data conversion when recording the MIDI signal in the subcode of the digital recording medium is performed. This has the effect of facilitating the operation.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a MIDI editing apparatus according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a MIDI editing apparatus according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing a MIDI editing apparatus according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram showing a MIDI editing apparatus according to a fourth embodiment of the present invention.

FIG. 5 is an explanatory diagram showing an example of soft resampling in a resampling step of an editing process.

[Explanation of symbols]

 1 Standard MIDI File 2 MIDI Signal Playback Section 3 MIDI Signal Recording Section 4 Standard MIDI File Conversion Section 5 Subcode Conversion Section 6 CD Cutting Device 7 SMPTE Time Code Generator

Claims (1)

[Claims] 1. A MIDI signal reproducing means for reproducing a MIDI signal from a file in which a MIDI sequence is recorded,
MID to resample and record the MIDI signal at a tempo that is a rational number multiple of the recording rate of the CD subcode
A MIDI editing device having I signal recording means.