ifft~ performs an Inverse FFT (inverse fast Fourier transform) on an input signal.
The first argument specifies the number of points (samples) in the IFFT. It must be a power of two. The default number of points is 512. The second argument specifies the number of samples between successive IFFTs. This must be at least the number of points, and must be also be a power of two. The default interval is 512. The third argument specifies the offset into the interval where the IFFT will start. This must either be 0 or a multiple of the signal vector size. ifft~ will correct bad arguments, but if you change the signal vector size after creating an ifft~ and the offset is no longer a multiple of the vector size, the ifft~ will not operate when signal processing is turned on.
Common Box Attributes
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.adds the object to the background layer, 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.
Sets the type style used by the object. The options are:
0 = 'regular'
1 = 'bold'
2 = 'italic'
3 = 'bold italic'
Sets the object's font.
Sets the object's font size (in points).
hidden [int] (default: 0)
Toggles whether an object is hidden when the patcher is locked.
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]
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]
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]
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.
Sets the color for the object's text in RGBA format.
Sets the justification for the object's text.
0 = 'left'
1 = 'center'
2 = 'right'
Multichannel Group Attributes
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 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.
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 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: . 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 , , or messages.
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.
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 message instead of the target attribute. The voice index of 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.
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).
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.
In right inlet: The imaginary part of a complex signal that will be inverse transformed.
If signals are connected only to the left inlet and left outlet, a real IFFT (inverse Fast Fourier transform) will be performed. Otherwise, a complex IFFT will be performed.
Multichannel Group Messages
message arguments [list]
Out left outlet: The real part of the inverse Fourier transform of the input. The output begins after all the points of the input have been received.
Out middle outlet: The imaginary part of the inverse Fourier transform of the input. The output begins after all the points of the input have been received.
Out right outlet: A sync that ramps from 0 to the number of points minus 1 over the period in which the IFFT output occurs. When the IFFT is not being output (in the case where the interval is larger than the number of points), the sync is 0.
|cartopol||Convert cartesian to polar coordinates|
|cartopol~||Signal Cartesian to Polar coordinate conversion|
|fft~||Fast Fourier transform|
|fftin~||Input for a patcher loaded by pfft~|
|fftinfo~||Report information about a patcher loaded by pfft~|
|fftout~||Output for a patcher loaded by pfft~|
|frameaccum~||Compute "running phase" of successive phase deviation frames|
|framedelta~||Compute phase deviation between successive FFT frames|
|pfft~||Spectral processing manager for patchers|
|poltocar||Convert polar to cartesian coordinates|
|poltocar~||Signal Polar to Cartesian coordinate conversion|
|vectral~||Vector-based envelope follower|
|MSP Analysis Tutorial 3: Using the FFT||MSP Analysis Tutorial 3: Using the FFT|