Description

GEN53 creates an impulse response function table with either a linear-phase or a minimum-phase characteristic. The source for this can either be a frequency response or an impulse response, stored in an existing table. Optionally, another function table can be used to window the input and/or the output of the process.

Syntax

f # time size 53 fsrc
    [mode fwin]

fsrc - source function table. If this is an impulse response, the size must match the created function table size. If a frequency response is used, then the created function size needs to be twice the size of this source. Power-of-two is required.

mode - optional, the operation mode, a sum of (a) input, frequency response (0) or impulse respone (1); (b) output, linear phase (0) or minimum-phase (2); (c) windowing, none (0), input (4) and/or output (8). The default mode (0) is frequency response input, linear-phase output, no windowing.

fwin - window function table, power-of-two size is required, but does not need to match the created function table size.

Example

Here is a complete example of the GEN53 generator. Play gen53.csd

<CsoundSynthesizer>
<CsOptions>
-o dac
</CsOptions>
<CsInstruments>


instr 1

a1 diskin "fox.wav"
a2 ftconv a1, p5, 256
   out a2*p4
   
endin

</CsInstruments>
<CsScore>
; impulse response
f1 0 131072 1 "ir.wav" 0 0 1
; minimum-phase version
f2 0 131072 53 1 3

; Hann window
f3 0 1024  20  1 1
; low-pass frequency response
f4 0 1024 7 0 100 0 24 1 900 1
; low-pass linear-phase IR
f5 0 2048 53 4 4 3 

;        scale  IR
i1  0  3 0.25   2
i1  +  3 1      5 
</CsScore>
</CsoundSynthesizer>

Credits

Author: Istvan Varga