phs — Obtains the phases of a complex-number array
This opcode returns the phases of a complex-number array, as a real-valued array with half the size of its input plus one. The reason for the extra point is to keep the array size equivalent to the output of the mags opcode (which is often used alongside this one).
kout[] -- output array containing the phases. It will be created if it does not exist.
kin[] -- input array containing the complex-valued real-imaginary input.
Here is an example of the phs opcode. It uses the file phs.csd.
Example 626. Example of the phs 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 needs to be an integer div of hopsize */ ksmps = 64 instr 1 ihopsize = 256 ; hopsize ifftsize = 2048 ; FFT size iolaps = ifftsize/ihopsize ; overlaps ibw = sr/ifftsize ; bin bandwidth kcnt init 0 ; counting vars krow init 0 kOla[] init ifftsize ; overlap-add buffer kIn[] init ifftsize ; input buffer kOlph[] init ifftsize/2+1 ; old phases kPhs[] init ifftsize/2+1 ; synthesis phases kDeltaOut[] init ifftsize/2+1 ; synthesis freqs kMagsOut[] init ifftsize/2+1 ; synthesis mags kOut[][] init iolaps, ifftsize ; output buffers a1 diskin2 "fox.wav",1,0,1 ; audio input /* every hopsize samples */ if kcnt == ihopsize then /* window and take FFT */ kWin[] window kIn,krow*ihopsize kSpec[] rfft kWin /* mags & phases */ kMags[] mags kSpec kPha[] phs kSpec /* phase diffs */ kDelta[] = kPha - kOlph kOlph = kPha /* pitch shift */ ki = 0 iscal = 1.25 ; maj 3rd up until ki == ifftsize/2 do if ki*iscal < ifftsize/2 then kDeltaOut[ki*iscal] = kDelta[ki]*iscal kMagsOut[ki*iscal] = kMags[ki] endif ki += 1 od /* accum phases */ kPhs = kDeltaOut + kPhs kSpec pol2rect kMagsOut,kPhs /* IFFT + window */ kRow[] rifft kSpec kWin window kRow, krow*ihopsize /* place it on out buffer */ kOut setrow kWin, krow /* zero the ola buffer */ kOla = 0 /* overlap-add */ ki = 0 until ki == iolaps do kRow getrow kOut, ki kOla = kOla + kRow ki += 1 od /* update counters */ krow = (krow+1)%iolaps kcnt = 0 endif /* shift audio in/out of buffers */ kIn shiftin a1 a2 shiftout kOla a1 delay a1, (ifftsize+ihopsize)/sr out a1*0.3+a2/iolaps /* increment counter */ kcnt += ksmps endin </CsInstruments> <CsScore> i1 0 10 </CsScore> </CsoundSynthesizer>