CN101251995A

CN101251995A - Method convenient to later stage modify and save through MIDI information to control audio integral sound effect

Info

Publication number: CN101251995A
Application number: CNA2008100081906A
Authority: CN
Inventors: 王逸驰
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-02-18
Filing date: 2008-02-18
Publication date: 2008-08-27

Abstract

The invention relates to a method for controlling overall audio effects through MIDI information for facilitating follow-up modifications and remedies. The method is as follows: MIDI information is used in the digital audio field to transmit DSP effector parameter control information so as to realize control of final effects of original audio. A music producer converts parameter information of an audio-class DSP effector to corresponding MIDI information which is saved as an independent MIDI file. When the music is played back, the MIDI information synchronous to the audio data is converted to the corresponding audio-class DSP effector parameters by the player through calculation, and the parameters of the effector are changed and then act on the audio signals so as to change auditory effect of the final output audio.

Description

A kind of by MIDI information Control audio frequency integral sound effect and be convenient to later stage modify and the method remedied

Technical field

This is in the control information of digital audio field utilization MIDI information transmission parameter, thereby realizes a kind of method to the control of original audio final effect.The personnel that implement this technical scheme should have the relevant knowledge that MIDI, DAB and DSP handle.

Technical background

Traditional music making flow process at first is that the recording engineer records, and gives the audio mixing slip-stick artist audio mixing then, gives the master tape slip-stick artist at last and carries out the master tape processing, gives factory's dish at quarter at last.In slip-stick artist's processing procedure, audio frequency effect devices such as a large amount of utilization equilibriums, compression and reverberation, thereby the sense of hearing of lifting works---just allow works sound more pleasing to the ear.

Under the conventional situation, CD that we hear or MP3, same song source can only be one, just the original cd or the audio file that provide of record company.The listening device difference that we use, effect be difference to some extent also: use the MP3 walkman and use the HIFI stereo set of a cover hundreds of thousands unit to listen a same first song, auditory effect differs widely.

If works are being found improper in the processing or error after the distribution, there is not possibility to carry out that the correction in later stage---CD carves yet, be impossible not scribing the correction-plate change again.Even if propagate with this form that diminishes tonequality of MP3, also need the client again download capability be the file of MB unit.Therefore, the music that we hear has determined that all mass audience or producer do not have the leeway of modification.

Summary of the invention

The control information that this method uses the MIDI storage to be correlated with realizes the control action for audio frequency, and main cause is:

MIDI extensively is applied to the form that professional music is made the field, and is compatible very good.The software that can edit MIDI is very universal.Do not use proprietary format and use the MIDI canned data, can popularize correlation technique quickly, bring very big facility yet for manufacturing terminal.

MIDI is a kind of standard and comprehensive standard, enough the storage information of being correlated with.And MIDI possesses the advantage on the capacity, and common MIDI file has only the size of several KB, is convenient to very much the new data of later stage transmission.

The present invention is divided into following 5 big classes with control information, the detailed description of itemizing below:

1. volume control information

One section sound of human perception, at first perception is the size of wave volume.Therefore in the control information of transmission, be essential for the control of volume.

2. frequency control information

Human perceives sound, another one is important to be exactly that frequency content is formed, and is presented as tone color.Change frequency content, just can change tone color.In the control information of transmission, will some information Control frequency content.These control informations will show any frequency range, and scope is much, and the such information of how many volumes gains or decay.

3. dynamically control information

Human perceives sound can be felt maximum acoustic and minimum sound.The two ratio is exactly usually said dynamic range, dynamically influences very much the sense of hearing of sound, and therefore in the control information of transmission, some is the control information that belongs to dynamically handling.

4. pitch control information

Human perceives sound, wherein significantly one of perception is exactly a pitch, that is to say that this sound is height or low.In the control information of transmission.Relevant control information is also arranged

5. other information

Do not belong to top 4 big classes, but, all belong to this class for implementing the effective information of control information, adding for expanding effect device institute reserved information position future

The definition of control information:

Control information has adopted the MIDI controller information to store, and that is to say that form is:

Wherein information category is fixed to the change of MIDI controller because we use the MIDI controller information.In sequencer, we can see that English is expressed as Control Change or is abbreviated as Controller or Ctrl, and the controller number is corresponding control information number, and data value is a correlation, according to the regulation of MIDI, this value span is the integer between the 0-127.Global Information is shown as Fig. 1 in sequencer Nuendo 3.

Complete control information definition tabulation, wherein c (n) refers to the n controller

(M/S is referred to as Mid (central authorities)/Side (both sides) stereophonic recording, and wherein default value is in the volume control of C1:M part

127,100% volume playback just)

The volume control of C2:S part

The phase place of C3:M part

The phase place of C4:S part

C5: centre frequency 1 (No. 5 controller to 24 controller control balance parameters parts)

The curve type of C6:1

The degree of gain of C7:1

The bandwidth of C8:1/Q value

C9: centre frequency 2

The curve type of C10:2

The degree of gain of C11:2

The bandwidth of C12:2/Q value

C13: centre frequency 3

The curve type of C14:3

The degree of gain of C15:3

The bandwidth of C16:3/Q value

C17: centre frequency 4

The curve type of C18:4

The degree of gain of C19:4

The bandwidth of C20:4/Q value

C21: centre frequency 5

The curve type of C22:5

The degree of gain of C23:5

The bandwidth of C24:5/Q value

C25: the threshold value (argument section of limit is pressed in No. 25 to No. 30 controller controls) of pressing limit

C26: the ratio of pressing limit

C27: the zero-time of pressing limit

C28: the release time of pressing limit

C29: the gain of pressing limit

C30: press the limit on off state (according to value from small to large for to close/to M partly work/to S partly work/act on whole passages of waveform)

C31: reverberation kind (be defaulted as 0 and be and do not use reverberation, the argument section of No. 31 to No. 40 controllers control reverberation)

C32: reverberation degree

C33: reverberation parameters 1

C34: reverberation parameters 2

C35: reverberation parameters 3

C36: reverberation parameters 4

C37: effect device reserves 1

C38: effect device reserves 2

C39: effect device reserves 3

C40: effect device reserves 4

C41: L channel type

C42: R channel type

C43: back L channel type

C44: back R channel type

C45: middle L channel type

C46: middle R channel type

C47: middle channel type

The C48:LFE channel type

The low level of C49:C1 replenishes byte (being used for replenishing the not enough problem of C1 precision)

The low level of C50:C2 replenishes byte

C51: whole pitch (value 63 is for changing pitch, less than 63 for reducing pitch, greater than 63 for increasing pitch, scope for upwards or next octave)

C52-C127: reserve (after being used for specific extended use)

The decoding end of sound signal, playback end in other words, built-in high-precision DSP effect device, and have the regulatory function of volume and phase place.The parameter of these parts, all corresponding unique class MIDI information is such as the N controller information.When these controller informations changed, these parameters also changed.What need exactissima diligentia is, the used effect device of DSP effect device that uses when must guarantee to edit the MIDI file and playback end is in full accord, different portfolio effect devices and compression effectiveness device can not occur.Can guarantee that so just the producer is identical with the playback end in the effect that editor obtains the time.

Like this, the music making people can make the different taste that different MIDI files adapts to the audience, and the audience only need be switched different MIDI files like this, just can enjoy the final effect of different taste.

Revise or remedy after audio file is openly issued if desired, the music making people can generate new MIDI file with relevant parameters information in sequencer, and the user replaces legacy version after only need downloading new MIDI file, can realize amended effect.

Implementation process

The enforcement of DSP effect device can be based on the hardware---and such as hardware DSP, special-purpose programmable chip FPGA etc. also can be pure softwareizations---handle based on CPU.

At first be to align MIDI file and wave file, be used for guaranteeing controller information accuracy in time.Here the speed of regulation MIDI is 120BPM, and just per minute 120 is clapped, and the time of MIDI file has just been determined like this.It is that the playback end need be prepared a MIDI file switch that a little details is arranged here, so that switch the MIDI file of different configurations.

In sequencer, also can realize with waveform synchronously.Play the MIDI file then when playing wave file, so the time has also alignd.When arriving sometime, the information of controller sends.System according to the controller number assignment to relevant parameters.

Here use a volume control information as an example, suppose that at a time a value is that 63 No. 1 controller information sends, system identification is master volume control, sends it to volume control, determines volume values according to value 63 then.If the volume range of adjustment of system is 20dB, calculate according to linear function, 63 should be half volume, just 10dB.

Another one example regulating frequency, supposing to transmit a value and be 127 No. 23 controllers, value and be No. 21 controllers of 120 and value and be 63 No. 24 controller informations comes, system identification is a frequency control information, will be worth accordingly to translate into parameter value, sends to the corresponding port and carries out.

Fig. 2 is the process of MIDI controller information to the parameter control information.Disposed the effect device of high precision, low distortion in decoding end, signal flows through these effect devices in turn, make corresponding processing according to control information.Fig. 3 is the whole flow process at the decoding end signal.

Equally, hold software, then need a cover and the identical DSP effect device of playback end, and can in sequencer, use to guarantee the unitarity of final effect the editor who prepares for the music making people.And whole flow process then is and the antipodal flow process of above-mentioned flow process, and whole flow process is reversible, has not just stated tired here.

Progress and advantage

1. provide possibility for later stage modify with remedying

Control information is provided, after finding to slip in the later stage, has an opportunity to remedy. Avoided again making redaction. Such as certain Part volume is too small, can give correction without detriment to tonequality in the later stage.

2. there is not significant change on the capacity

Because the MIDI file is only stored some command content, so capacity is very little, only has the capacity of several K sizes, and is far away little Be the memory space of unit in MB, therefore transmit the needed time of this class control information and cost approaches zero, very convenient at capacity Different versions is provided under the condition of not obvious variation. If need to revise, the data that only need a few KB capacity of transmission both can, because of This need to transmit in the situation of update information or different editions, and comfort level will far surpass traditional audio format.

3. provide more selection scheme for the audience

Owing to use MIDI information can control the DSP effect, this just provides the possibility of making the different taste version for the producer, The more important thing is and on capacity, also do not have obvious growth. These different versions can be used for adapting to different audiences' taste. Like the dynamically music of big, low-and high-frequency comparison stimulus such as some young man. And just can produce the young man by control information The version of liking. Only increasing at capacity and adapt to the different taste needs of audience under the prerequisite of several KB, is the maximum excellent of this technology Gesture.

4. for the music making people provides the more free degree, the making flow process is optimized and accelerates

Owing to can make a plurality of different editions, the music making people can make several versions allows the audience select, and needn't rack brain Juice attempts to select the version an of the best as final version. Alleviated like this music making people's pressure, removed simultaneously and determine After whole this step of version, whole music is given birth to journey and can be accelerated.

Description of drawings

Fig. 1 is the data presentation of the MIDI information among the software Nuendo 3 of making at professional music, from left to right is followed successively by MIDI information category (controller controller), start time, controller number, numerical value.

Fig. 2 is for being converted into the MIDI controller information process of parameter control information

Fig. 3 is the whole flow process at the decoding end signal

Claims

1. one kind by MIDI information Control audio frequency integral sound effect and be convenient to later stage modify and the method remedied, it is characterized in that the music making people is converted into corresponding M IDI information with the parameter information of audio class DSP effect device, be stored as independently MIDI file, player will calculate with the synchronous MIDI information via of voice data and transform into corresponding audio class DSP effect device parameter during playback, act on sound signal behind the parameter change of above-mentioned effect device, thereby make integral sound effect produce the change that can be used for later stage modify, remedy and make different editions.

2. described a kind of by MIDI information Control audio frequency integral sound effect and be convenient to later stage modify and the method remedied according to claim 1, it is characterized in that using MIDI information such as MIDI controller information, MIDI note information and MIDI system directive information.

3. described a kind of by MIDI information Control audio frequency integral sound effect and be convenient to later stage modify and the method remedied according to claim 1, it is characterized in that having used volume control, pitch control, equilibrium, compression, restriction, reverberation, multistage equilibrium, multistage compression, multistage restriction, fringing, chorus and tamber simulation effect device.