downsamp

Modify a signal by down-sampling.

Syntax

kres downsamp asig [, iwlen]

Initialization

iwlen (optional) -- window length in samples over which the audio signal is averaged to determine a downsampled value. Maximum length is ksmps; 0 and 1 imply no window averaging. The default value is 0.

Performance

downsamp converts an audio signal to a control signal by downsampling. It produces one kval for each audio control period. The optional window invokes a simple averaging process to suppress foldover.

Examples

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

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

sr = 44100
ksmps = 32
nchnls = 2
0dbfs  = 1

instr   1

ifrq    = cpspch(p4)
ain     diskin2 "drumsMlp.wav", 1
aenv    follow  ain, .001       ;take the amplitude every 1/1000th of a second
alow    tone    aenv, 25        ;lowpass-filter (25 Hz) for a clean signal
kenv    downsamp alow
asig    pluck   kenv, ifrq, 15, 0, 1
        outs    asig, asig
        endin

</CsInstruments>
<CsScore>

i 1 0 2  9
i 1 + .  7
i 1 + .  5

e
</CsScore>
</CsoundSynthesizer>

See also

Sample Level Operators