binit — PVS tracks to amplitude+frequency conversion.


The binit opcode takes an input containg a TRACKS pv streaming signal (as generated, for instance by partials) and converts it into a equal-bandwidth bin-frame containing amplitude and frequency pairs (PVS_AMP_FREQ), suitable for overlap-add resynthesis (such as performed by pvsynth) or further PVS streaming phase vocoder signal transformations. For each frequency bin, it will look for a suitable track signal to fill it; if not found, the bin will be empty (0 amplitude). If more than one track fits a certain bin, the one with highest amplitude will be chosen. This means that not all of the input signal is actually 'binned', the operation is lossy. However, in many situations this loss is not perceptually relevant.


fsig binit fin, isize


fsig -- output pv stream in PVS_AMP_FREQ format

fin -- input pv stream in TRACKS format

isize -- FFT size of output (N).


Here is an example of the binit opcode. It uses the file binit.csd.

Example 102. Example of the binit opcode.

See the sections Real-time Audio and Command Line Flags for more information on using command line flags.

; Select audio/midi flags here according to platform
-odac     ;;;RT audio out
;-iadc    ;;;uncomment -iadc if RT audio input is needed too
; For Non-realtime ouput leave only the line below:
; -o binit.wav -W ;;; for file output any platform

sr = 44100
ksmps = 32
nchnls = 2

instr 1
;ain inch 1				; for live input
ain	diskin	 "drumsMlp.wav", 1		; input signal
fs1,fsi2 pvsifd	 ain, 2048, 512, 1		; ifd analysis
fst	partials fs1, fsi2, .003, 1, 3, 500	; partial tracking
fbins	binit	 fst, 2048		; convert it back to bins
aout	pvsynth	 fbins			; overlap-add resynthesis
	outs	 aout, aout



i 1 0 2


The example above shows partial tracking of an ifd-analysis signal, conversion to bin frames and overlap-add resynthesis.

See also

Tools for Real-time Spectral Processing (pvs opcodes)


Author: Victor Lazzarini
February 2006

New in Csound5.01