mc.omx.comp~

OctiMax Compressor (multichannel)

Description

omx.comp~ is a fully-featured signal compressor with limiting, gating, sidechain, and dual-band options.

Arguments

None.

Attributes

Common Box Attributes

annotation [symbol]

Sets the text that will be displayed in the Clue window when the user moves the mouse over the object.

background [int] (default: 0)

Adds or removes the object from the patcher's background layer. background 1 adds the object to the background layer, background 0 removes it. Objects in the background layer are shown behind all objects in the default foreground layer.

color [4 floats]

Sets the color for the object box outline.

fontface [int]

Sets the type style used by the object. The options are:

plain
bold
italic
bold italic

Possible values:

0 = 'regular'
1 = 'bold'
2 = 'italic'
3 = 'bold italic'

fontname [symbol]

Sets the object's font.

fontsize [float]

Sets the object's font size (in points).

Possible values:

'8'
'9'
'10'
'11'
'12'
'13'
'14'
'16'
'18'
'20'
'24'
'30'
'36'
'48'
'64'
'72'

hidden [int] (default: 0)

Toggles whether an object is hidden when the patcher is locked.

hint [symbol]

Sets the text that will be displayed in as a pop-up hint when the user moves the mouse over the object in a locked patcher.

ignoreclick [int] (default: 0)

Toggles whether an object ignores mouse clicks in a locked patcher.

patching_rect [4 floats] (default: 0. 0. 100. 0.)

Sets the position and size of the object in the patcher window.

position [2 floats]

g/s(set)

Sets the object's x and y position in both patching and presentation modes (if the object belongs to its patcher's presentation), leaving its size unchanged.

presentation [int] (default: 0)

Sets whether an object belongs to the patcher's presentation.

presentation_rect [4 floats] (default: 0. 0. 0. 0.)

Sets the x and y position and width and height of the object in the patcher's presentation, leaving its patching position unchanged.

rect [4 floats]

g/s(set)

Sets the x and y position and width and height of the object in both patching and presentation modes (if the object belongs to its patcher's presentation).

size [2 floats]

g/s(set)

Sets the object's width and height in both patching and presentation modes (if the object belongs to its patcher's presentation), leaving its position unchanged.

textcolor [float]

Sets the color for the object's text in RGBA format.

textjustification [int]

Text Justification

Possible values:

0 = 'left'
1 = 'center'
2 = 'right'

varname [symbol]

Sets the patcher's scripting name, which can be used to address the object by name in pattr, scripting messages to thispatcher, and the js object.

Multichannel Group Attributes

chans [int]

The chans attribute sets the number of channels and instances in the MC wrapper object. If you want a fixed number of channels regardless of what is connected to the object, you could set chans via a typed-in argument, for example typing mc.cycle~ @chans 100 would create 100 instances of a cycle~ object inside the MC wrapper. If chans is 0, the wrapper object will auto-adapt to the number of channels in its input multichannel signals (using the maximum of all connected signals). For objects without connected multichannel signals, the chans attribute will need to have a non-zero value if you want more than one instance.

If chans is changed while the audio is on, the number of instances will not updated until audio is restarted. However, if chans is reduced while the audio is on, any extra channels will no longer process audio and will output a zero signal.

values [int]

The values attribute only applies to object creation time so it must be set via typed-in argument syntax. values sets the first (and only the first) initial argument for successive instances in the MC wrapper. For example, typing mc.cycle~ @chans 4 @values 50 60 70 80 would assign an initial frequency to the cycle~ instances inside the wrapper. The first instance would be assigned a frequency of 50, the second a frequency of 60, the third 70, and the fourth 80. Note that values does not determine the actual instance count; this can be done using the chans attribute. If there are more instances than elements for the values attribute, those instances are instantiated with the default value.

If you want to set a default initial value for all instances, simply type it as an argument before any typed-in attributes. For example, modifying our example above: mc.cycle~ 100 @chans 10 @values 50 60 70 80. In this example, the first four instances are set as before, but the next six are created with a frequency argument of 100.

To change instance values or attributes after the wrapper object has been created, use the setvalue, applyvalues, or replicatevalues messages.

replicate [int]

When replicate is enabled, input single-channel or multichannel signals containing fewer channels than the number instances in the MC wrapper object are repeated to fill all input channels. For example, when replicate is enabled and you connect a two-channel multichannel signal to the input of an MC wrapper object with four instances, channel 1 of the input will be repeated to channel 3, and channel 2 of the input will be repeated to channel 4. If replicate were disabled, channels 3 and 4 of the input would be set to zero.

target [int]

The target attribute sets a voice index for targeting specific wrapper instances. Subsequent messages are directed to an individual instance instead of all instances. It is strongly recommended you use the more reliable setvalue message instead of the target attribute. The voice index of setvalue will override the current setting of target. When target is 0, incoming messages are sent to all instances. When target is -1, incoming messages do nothing.

usebusymap [int]

When usebusymap is enabled, the MC wrapper controls whether individual instances process audio using a busy map maintained by either an mc.noteallocator~ or mc.voiceallocator~ object. When a channel in the busy map is marked as "free" or "released" no audio processing occurs by any instance on the channel corresponding to the voice index. When usebusymap is disabled, instances in the MC wrapper process audio at all times. This will also be true if usebusymap is enabled and there is no local or named busy map available. (See the busymapname attribute for a description of local and named busy maps).

zero [int]

When the zero attribute is enabled, channels in the MC wrapper due to the use of a busy map output zero signals. To save a small amount of CPU at the risk of loud and unpleasant noises due to uncleared signal data, you can disable zero. In this case, disabled channels in the MC wrapper do nothing to their output channels. If usebusymap is disabled or there is no active local or named busy map available, the setting of the zero attribute has no effect.

Conveniently, when usebusymap is enabled in mc.mixdown~ object, disabled channels are not mixed to the output. When unused signals from wrapped objects with zero disabled feed into mc.mixdown~, they will be ignored, reducing the risk of unpleasantness getting past the mix output.

busymapname [symbol]

When the usebusymap attribute is enabled, an MC wrapper object uses the local busy map of any mc.voiceallocator~ or mc.noteallocator~ in the same patcher by default. To use a named global busy map instead, set the busymapname attribute to the desired name.

Messages

agcEnabled

Arguments

compression-enable-flag [int]
The word agcEnabled, followed by a 1 or 0, enables or disables the compressor.

agcThreshold

Arguments

compression-threshold [float]
The word agcThreshold, followed by a number, sets the compressor threshold (in dB below full scale). This is the main compression threshold. Any signal above the threshold will be reduced, and any signal below the threshold will be amplified, according to the range and ratio parameters.

attack

Arguments

attack-rate [int]
The word attack, followed by a number, sets the rate at which the compressor is engaged when the signal level exceeds the agcThreshold. The value range is 0-150 on a logarithmic scale, with larger values indicating faster attack.

bypass

Arguments

bypass-flag [int]
The word bypass followed by a non-zero number will output the dry unchanged input signal straight out the outlet without any processing; followed by a 0, will output the signal effected by omx.comp~.

channelCoupling

Arguments

keying-source (0, 1, or 2) [int]
The word channelCoupling, followed by a number, sets the gain control source as follows: 0 = stereo, 1 = left, 2 = right. In stereo mode, the gain control signal is derived from whichever channel is loudest, unlike in left or right mode where the gain control signal will only be derived from the selected channel. This can be used for "keying" or "ducking" effects, where the energy of one sound modulates the level of another.

choosePreset

Arguments

preset-number [int]
The word choosePreset, followed by a number in the range 0-4, selects a preset for the omx.comp~ object. These presets are to be considered "starting points" and should be tweaked for your particular purpose or desired sound. The preset options are:

0: Guitar
1: Bass
2: Vocal
3: Drums
4: Program Material - An attempt at smooth "gain riding" of mixed program material as well as can be done with a non-multiband processor.

delay

Arguments

delay-time [int]
The word delay, followed by a number, sets the sidechain delay time (in milliseconds). This emulates the attack characteristics of vintage "opto" compressors, and similar effects. The delay is applied to the control signal only, and hence may result in large peaks at transients.

dualBandEnabled

Arguments

crossover-enable-flag [int]
The word dualBandEnabled, followed by a 1 or 0, turns dual band mode on or off. In dual band, a crossover filter around 200hz splits the audio into two bands, which are compressed separately. This can reduce bass pumping and other artifacts of wide-band compression.

freezeLevel

Arguments

release-action-threshold [float]
The word freezeLevel, followed by a number, sets the freeze threshold (in dB below full scale). When the signal is below this threshold, the compressor release action will be suppressed, and the gain will remain constant. In normal operation, release action takes place when the signal is below the compression threshold, increasing the gain until the signal returns to its full-scale, uncompressed level. If there is no usable signal present, this can have the effect of simply amplifying the noise floor. Release gate and freeze can suppress gain recovery to avoid this condition.

gatingLevel

Arguments

release-gate-threshold [float]
The word gatingLevel, followed by a number, sets the release gate threshold (in dB below full scale). When the signal is below this threshold, the release time of the compressor will be slowed by a factor of 3. See freezeLevel.

limEnabled

Arguments

peak-limiter-flag [int]
The word limEnabled, followed by a 1 or 0 turns the peak-limiter on or off.

limMode

Arguments

response-mode-flag [int]
The word limMode, followed by a number, sets the limiter response mode as follows: 0 = punchy, 1 = smooth. Punchy response yields extremely short attack and release times, useful for transparent limiting, or to create loudness. However, if over-used, intermodulation distortion may result. Smooth response uses longer attack and release times. The result is still a fast look-ahead limiter, but with less intermodulation distortion and less punch.

meterData

The word meterData will cause output (by instantaneous command as opposed to metering-interval described by the meterRate message) of values which describe the current state of various internal gain levels of the compressor, and can be used to drive GUI objects to provide visual feedback. omx.comp~ sends a list of six integers, describing compressor gain (left, right), noise gate gain (left, right), and limiter gain (left, right).

meterRate

Arguments

data-output-interval [int]
The word meterRate, followed by a number, specifies the interval (in milliseconds) at which the meter data described above will be sent.

meters

Arguments

metering-enable-flag [int]
The word meters, followed by a 1 or 0, turns the metering output on or off. When metering is on, a list of values will be sent from the rightmost outlet at a rate specified by the meterRate message. These values describe the current state of various internal gain levels of the compressor, and can be used to drive GUI objects to provide visual feedback. omx.comp~ sends a list of six integers, describing compressor gain (left, right), noise gate gain (left, right), and limiter gain (left, right).

ngEnabled

Arguments

noise-gate-flag [int]
The word ngEnabled, followed by a 1 or 0, turns the noise gate on or off. A noise gate is effective for reducing background hiss when no other signal is present. Here, it's implemented as a downward expander with a ratio of 2:1.

ngThreshold

Arguments

noise-gate-threshold [float]
The word ngThreshold, followed by a number, sets the threshold level (in dB below full scale) at which the noise gate will be engaged.

progressiveRelease

Arguments

release-mode-flag [int]
The word ProgressiveRelease, followed by a 1 or 0, enables or disables the Progressive Release mode, which causes the compressor to release faster during heavy gain reduction. This means that the audio will sound more compressed when the input signal is louder. This can be used to create an illusion of dynamics. It is especially useful with the ratio set to Infinite:1, which could sound over-compressed without this option.

range

Arguments

maximum-gain-amplification [float]
The word range, followed by a number, sets the maximum amount of gain amplification allowed in dB. This limits the gain that is applied when the signal is below the compression threshold. Note that this limiting takes place before the ratio is applied. For example, if the range is set to 24 dB, and the ratio is 2:1, the most gain amplification you can get (after the ratio is applied) is in fact 12 dB.

ratio

Arguments

gain-reduction-ratio-numerator [int]
The word ratio, followed by a number, sets the numerator of the compressor gain reduction ratio, from 1:1 to Infinite:1.

release

Arguments

release-rate [int]
The word release, followed by a number, sets the rate at which the compressor releases its gain adjustment when the signal level no longer exceeds the agcThreshold. The value range is 0-150 on a logarithmic scale, with larger values indicating faster release. This rate can be modified by the release gate and freeze thresholds.

saveSettings

The word saveSettings causes all parameter values to be sent out the third outlet.

sidechainFilterEnabled

Arguments

keying-attenuation-flag [int]
The word sidechainFilterEnabled, followed by a 1 or 0, enables or disables an attenuation filter in the upper midrange that makes the compressor less sensitive to vocal signals, and generally produces a more gentle response. This filter is only applied internally, to the control signal. Note that it may cause more output overshoots, where the signal output level exceeds 0dB.

signal

Audio input, the signal or pair of signals to be compressed.

smoothGain

Arguments

smoothing-flag [int]
The word smoothGain, followed by a 1 or 0, enables or disables gain smoothing. This applies a low-pass filter to the control signal, and is useful both to prevent artifacts (gain fluttering) from high attack/release rates, and to intentionally make the compressor sluggish, adding extra "snap" to transients.

Multichannel Group Messages

deviate

Arguments

range [float]
message-name [symbol]
center-value [float]
Generate a random value for each channel around a center value. If no message name is provided then a float message is used by default.

exponential

Arguments

exponent [float]
base [float]
The exponential message generates an exponential series using the second argument as a base and the first argument as an exponent.

scaledexponential

Arguments

exponent [float]
base [float]
The scaledexponential message generates an exponential series using the second argument as a base and the first argument as an exponent. Values are scaled by the instance number, so the total range of the series is independent of the number of channels.

increment

Arguments

increment-amount [float]
message-name [symbol]
start-value [float]
Generate a increasing value for each channel starting at a specified value. If no message name is provided then a float message is used by default.

harmonic

Arguments

multiplier [float]
fundamental [float]
The harmonic message generate a harmonic series using the second argument as the fundamental frequency and the first argument as a multiplier.

subharmonic

Arguments

multiplier [float]
fundamental [float]
The subharmonic message generate a subharmonic series using the second argument as the fundamental frequency and the first argument as a multiplier.

spread

Arguments

boundary-value [float]
message-name [symbol]
other-boundary-value [float]
Generate a range of values distributed to each channel. If no message name is provided then a float message is used by default. The first boundary value is included in the range outputs, but the last boundary value is not.

spreadinclusive

Arguments

boundary-value [float]
message-name [symbol]
other-boundary-value [float]
Generate a range of values distributed to each channel. If no message name is provided then a float message is used by default. Both the first and last boundary values are included in the range outputs.

spreadexclusive

Arguments

boundary-value [float]
message-name [symbol]
other-boundary-value [float]
Generate a range of values distributed to each channel. If no message name is provided then a float message is used by default. Neither the first nor last boundary values are included in the range outputs.

spreadincludefirst

Arguments

boundary-value [float]
message-name [symbol]
other-boundary-value [float]
Generate a range of values distributed to each channel. If no message name is provided then a float message is used by default. The first boundary value is included in the range outputs, but the last boundary value is not. The spreadincludefirst message is the same as the spread message.

spreadincludesecond

Arguments

boundary-value [float]
message-name [symbol]
other-boundary-value [float]
Generate a range of values distributed to each channel. If no message name is provided then a float message is used by default. The first boundary value is not included in the range outputs, but the last boundary value is included.

setvalue

Arguments

channel [int]
message [symbol]
message arguments [list]
The word setvalue, followed by both a channel index (starting at 1) and any message that can be sent to the wrapped object, sends the message to an individual instance within the MC wrapper. setvalue 0, followed by a message, sends the message to all instances. The setvalue message can be used in any inlet.

applyvalues

Arguments

message-name [symbol]
values [list]
The word applyvalues, followed by an optional message name and one or more message arguments, sends individual values in the arguments successively to instances in the MC wrapper, starting with the first instance. For example, the message applyvalues 4 5 6 will send 4 to the first instance, 5 to the second instance, and 6 to the third instance. If there are more instances than arguments to applyvalues, the extra instances are unaffected.

replicatevalues

Arguments

message-name [symbol]
values [list]
The word replicatevalues, followed by an optional message name and one or more message arguments, sends individual values in the arguments successively to instances in the MC wrapper, starting with the first instance. Unlike applyvalues, the replicatevalues message continues sending values to successive instances, restarting with the first element, if it runs out of arguments to send. For example, replicatevalues 4 5 to an MC wrapper object with three instances will send 4 to the first instance, 5 to the second instance, and 4 to the third instance.

Output

list

Out right outlet: when metering is turned on (via the meters message), a list will be output describing various internal levels. See meters, above.

signal

Out leftmost two outlets: the input signals (if present), with dynamics processing applied.

See Also

Name Description
omx.4band~ OctiMax 4-band Compressor
omx.5band~ OctiMax 5-band Compressor
omx.peaklim~ OctiMax Peak Limiter
MSP Compression Tutorial 2: Basic Compression MSP Compression Tutorial 2: Basic Compression
MSP Compression Tutorial 3: Tweaking Compression MSP Compression Tutorial 3: Tweaking Compression
MSP Compression Tutorial 4: Compression on Real Instruments MSP Compression Tutorial 4: Compression on Real Instruments
MSP Compression Tutorial 10: Controlling Feedback MSP Compression Tutorial 10: Controlling Feedback