Cycling '74 RNBO RNBO FFT RNBO Analysis ifft Inverse Fast Fourier Transform

ifft~ performs an Inverse FFT (inverse fast Fourier transform) on an input signal.

Number of FFT Samples

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.

Spectral Frame Size

The second argument specifies the number of samples between successive IFFTs. This must be at least the number of points, and must also be a power of two. The default interval is 512.

Phase

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.

Imaginary input

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 will be performed. Otherwise, a complex IFFT will be performed.

Real input

The real 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 will be performed. Otherwise, a complex IFFT will be performed.

Banging this attribute will reset the object to its default state. If multiple buffer names are declared to be used, this sets the currently active buffer using an index [0 based]. Real input

The real 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 will be performed. Otherwise, a complex IFFT will be performed.

Imaginary input

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 will be performed. Otherwise, a complex IFFT will be performed.

Real output

The real part of the inverse Fourier transform of the input. The output begins after all the points of the input have been received.

Imaginary output

The imaginary part of the inverse Fourier transform of the input. The output begins after all the points of the input have been received.

Ramp from 0 to (number of points - 1)

A sync signal 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 signal is 0.