AMIS : Manual

INTRODUCTION:

 

AMIS is a software MIDI interface based on the ideas of Granular synthesis. It is not a Granular synthesizer by means of altering the physics of a sound rather it is a method of organizing MIDI information based mainly on the Asynchronous cloud streams approach of organizing Granular synthesis events. However, AMIS does not particularly follow any particular Granular implementation. AMIS is a software aimed for live music performances therefore it generates data in real-time. Consequently, some classic Asynchronous GS implementations such as the pre-defined cloud duration are abandoned here. Yet, other included features, such as parameter linkage (internal parameter), bring this interface closer to other particle synthesis methods such as Grainlet synthesis. My general idea was to providing the user with plenty of control, but at the same time to allow some creative musical interpretations to be taken by the AMIS algorithms.    

AMIS essentially provides an extra layer of control to any musical device being able to accept MIDI data and output sound. This device can either be an external MIDI module or even an internal software synthesizer (by using the MIDI Yoke or similar drivers). Therefore, AMIS is not constrained by internal wavetables, instead it provides control of any waveform available on the available MIDI system – either sampled or synthesized. This functionality introduces Granular synthesis to any MIDI device connected with the AMIS interface and therefore extends the musical possibilities of the connected instrument. AMIS can easily produce in real-time, intense clouds of sound, combined of hundreds of elementary particles, which can vary in frequency and time according either to stochastic or probabilistic functions. The automated functions of the AMIS interface facilitate the generations of these sound particles – the grains – and thus make it ideal for real-time performances of Granular synthesis. Furthermore, AMIS can be controlled by an external MIDI device that outputs MIDI data, in order for the user to discard the PC interface completely.  

      

 

 

AMIS - USER MANUAL

 

To use the help menu in AMIS, press [HELP] once and move the mouse over a specific function. The explanation of the current function will appear on the main panel of AMIS.   

 

[A] = Automated parameter.

 

 

SLIDERS

 

GRAIN FREQUENCY:  [A]

It sets the fundamental frequency of the grains (between 20 - 20000 Hertz).

 

FREQ DEVIATION: [A]

It controls the amount of deviation of the centre frequency (measured in Hertz). The manner of deviation is controlled by the DEVIATION TYPE BUTTONS below this slider. In [UP] position the output frequency is calculated by a random value taken out of the summation of the fundamental frequency with the deviation amount. In [DOWN] position the output frequency is calculated by a random value taken out of the subtraction of the fundamental frequency with the deviation amount. In [BOTH] position the output frequency is calculated by a random value taken out of the summation and the subtraction of the fundamental frequency with the deviation amount. Negative frequencies mirrored in the positive frequency band.

 

LOW DENSITY: [A]

It indicates the upper density band limit of the cloud. High values will produce sparse clouds. Together with HIGH DENSITY, they specify the density spectrum of the cloud. When the density of the cloud is set to Asynchronous Variance mode, the LOW DENSITY slider is used to set the base density value, while the[UP], [DOWN] and [BOTH] buttons indicate the direction of the deviated base density value.

 

HIGH DENSITY:

It specifies the lower density band of the cloud. Together with LOW DENSITY they specify the density spectrum of the cloud. When the density of the cloud is set to Asynchronous Variance, then the HIGH DENSITY slider sets the amount of variance of the mean density value.

 

GRAIN DURATION: [A]

It sets the grain’s duration either in Channel 1 or 2. Use MIDI REMOTE to switch between Channels 1 and 2.

 

SUM DEV CHA 2: [A]

It introduces a controlled amount of frequency deviation for channel 2. The deviated frequency value for channel 2 is taken of the current frequency of Channel 1.

 

FREQ BAND LOW:

When the FREQ RND SEL is set to BAND, FREQ BAND LOW controls the lower limit of the band from which a random frequency value will be assigned as the fundamental frequency for the grains. Together with FREQ BAND HIGH they specify the frequency bandwidth of the cloud.

 

FREQ BAND HIGH:

When the FREQ RND SEL is set to BAND, FREQ BAND HIGH controls the upper limit of the band from which a random frequency value will be assigned as the fundamental frequency of the grains. Along with FREQ BAND LOW they specify the frequency bandwidth of the cloud.

 

CHA 1 VOL: [A]

It sets the MIDI volume for Channel 1 (values 0-127).

 

 

 

SLIDERS cont.

 

CHA 2 VOL: [A]

It sets the MIDI volume for Channel 2 (values 0-127).

 

SYNCHRONOUS:

When the cloud has been selected as synchronous, the SYNCHRONOUS slider sets the density of this cloud. 

 

DLY CHA 2:

It introduces a delay between Channel 1 and Channel 2 MIDI outputs (Max 2 seconds / values in ms).

 

BUTTONS

 

GENERATE On / Off:

It starts the generation of the MIDI streams.

 

FREQ TO DUR:

When active, the duration of the MIDI grains is inversely proportional of the fundamental frequency of the grains (High frequency values will produce shorter grain durations).

 

FREQ TO DENS:

When active, the LOWER DENSITY value of the cloud is proportional of the output frequency (High frequency values return a dense cloud).

 

DENS AUTO:

It controls the density automation (ON and OFF).

 

FREQ AUTO:

It controls the frequency automation (ON and OFF).

 

PATCH AUTO:

It controls the MIDI Program Change automation (ON and OFF). The left [TARGET] fields set the target Program Change number, while the [PROP] right fields set the probability value. High [PROP] values will reduce the occurrence of a MIDI Program Change event.

 

FREQ RND SEL

It toggles between the two different modes of AMIS frequency generation. In standard Fc position the frequency of the grains is the result of the deviation of the centre frequency (Fc). If the deviation is zero, then the frequency of the grains is the Fc value. In BAND position the frequency of the grains is the result of a random selection from within the   lower and upper frequency band.

 

 

 

BUTTONS cont.

 

 

MIDI ROUTE::

It switches between Channel 1 and Channel 2. External MIDI control for the grain Duration and Volume will apply to the selected channel.

 

CLOUD SELECT:

It switches between an Asynchronous (standard position), Asynchronous Variance and a Synchronous cloud. In standard position the density of the cloud is set by a random value taken from a specified bandwidth. In Asynchronous variance the density of the cloud is set by a random deviation of the base density.

In synchronous mode, the density of the cloud is synchronous and is controlled by a separate slider found next to the Synchronous button selection. 

 

VEL TO DENS:

When active, the density of the cloud is proportional to the velocity of a note played on the keyboard. High velocity values will increase the density of the grains within the cloud.

 

DENS TO FREQ

When active, the frequency of the grain is controlled by the LOW DENSITY value. The resulting frequency value is inversely proportional of the LOW DENSITY value (High LOW DENSITY values will increase the fundamental frequency of the grains).

 

MIDI PROG:

It changes the MIDI Program Change number for channels one and two.

 

FIELDS

 

AUTOMATION / FREQ TIME: (FREQ AUTO should be active)

It specifies the Time in milliseconds at which an update in frequency will occur as specified in the FREQ STEP field.

 

AUTOMATION / FREQ STEP: (FREQ AUTO should be active)

It specifies the amount of frequency change (STEP) that will occur, as frequent as specified in the FREQ TIME field.

 

AUTOMATION / DENS TIME: (DENS AUTO should be active)

It specifies the amount of Time in milliseconds at which an update in density will occur as specified in the DENS STEP field.

 

AUTOMATION / DENS STEP: (DENS AUTO should be active)

It specifies the amount of density change (STEP) that will take occur, as frequent as specified in the DENS TIME field.

 

PATCH AUTO / TARGET: (PATCH AUTO should be active)

It sets the desirable MIDI Program Change number (Patch) that will automatically be selected (triggered by the PATCH PROP values).

 

 

 

FIELDS cont.

 

PATCH AUTO / PROP: (PATCH AUTO should be active)

It sets the weighted value, corresponding to the TARGET field value. Is used to calculate how often a MIDI Program Change event will occur.  A high value will give less chances of occurrence.

 

MIDI PROG 1:

It sets the MIDI Program Change number for Channel 1

 

MDI PROG 2:

It sets the MIDI Program Change number for Channel 2

 

 

PANEL

 

MIDI PORTS:

It shows all available MIDI ports and used to assign the appropriate MIDI In and MIDI Out ports.

 

CTRLS:

It captures incoming MIDI message (e.g. MIDI controllers numbers from external MIDI devices) and assign them to certain AMIS automated functions.

 

GRAPH:

It controls the generation of the visual cloud representation.

 

MIDI IN:

It permits incoming MIDI messages (ON and OFF). When is ON, AMIS can be controlled by an external MIDI controller.

 

 

 

Dimitris Barnias 2004-09-10

 

 

Top^

 

 

©sonicspace.org 2005