fftinv — Complex-to-complex Inverse Fast Fourier Transform.
Applies an Inverse Fast Fourier Transform to a complex-value input 1-dimensional array producing a complex-valued output. The output is another array containing the complex-valued signal, and both arrays are arranged in interleaved real-imaginary format. The output array will have the same size as the input, and the transform size will be equivalent to half of the length of the array. Non-power-of-two transforms are limited to even sizes with not too many factors.
kout[] -- output array containing the complex-valued output. It will be created if it does not exist.
kin[] -- input array containing the complex-valued input.
Here is an example of the fftinv opcode. It uses the file ifft.csd.
Example 459. Example of the fftinv opcode.
See the sections Real-time Audio and Command Line Flags for more information on using command line flags.
<CsoundSynthesizer> <CsOptions> -d -o dac </CsOptions> <CsInstruments> ksmps = 64 instr 1 ifftsize = 1024 kcnt init 0 kIn[] init ifftsize kOut[] init ifftsize a1 oscili 0dbfs/2, 440 if kcnt >= ifftsize then kCmplx[] r2c kIn kSpec[] fft kCmplx kCmplx ifftinv kSpec kOut c2r kCmplx kcnt = 0 endif kIn[] shiftin a1 a2 shiftout kOut kcnt += ksmps out a2 endin </CsInstruments> <CsScore> i1 0 10 </CsScore> </CsoundSynthesizer>