ctrl21

Allows a floating-point 21-bit MIDI signal scaled with a minimum and a maximum range.

Syntax

idest ctrl21 ichan, ictlno1, ictlno2, ictlno3, imin, imax [, ifn]
kdest ctrl21 ichan, ictlno1, ictlno2, ictlno3, kmin, kmax [, ifn]

Initialization

idest -- output signal

ichan -- MIDI channel number (1-16)

ictlno1 -- most-significant byte controller number (0-127)

ictlno2 -- mid-significant byte controller number (0-127)

ictlno3 -- least-significant byte controller number (0-127)

imin -- user-defined minimum floating-point value of output

imax -- user-defined maximum floating-point value of output

ifn (optional) -- table to be read when indexing is required. Table must be normalized. Output is scaled according to imax and imin val.

Performance

kdest -- output signal

kmin -- user-defined minimum floating-point value of output

kmax -- user-defined maximum floating-point value of output

ctrl21 (i- and k-rate 21 bit MIDI control) allows a floating-point 21-bit MIDI signal scaled with a minimum and a maximum range. Minimum and maximum values can be varied at k-rate. It can use optional interpolated table indexing. It requires three MIDI controllers as input.

ctrl21 differs from midic21 because it can be included in score oriented instruments without Csound crashes. It needs the additional parameter ichan containing the MIDI channel of the controller. MIDI channel is the same for all the controllers used in a single ctrl21 opcode.

Examples

Here is an example of the ctrl21 opcode. It uses the file ctrl21.csd.

<CsoundSynthesizer>
<CsOptions>
; Select audio/midi flags here according to platform
-odac   -M0  ;;;RT audio I/O with MIDI in
;-iadc    ;;;uncomment -iadc if RT audio input is needed too
</CsOptions>
<CsInstruments>

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

instr 1 ; expects MIDI controller input on channel 1
; run and move your midi controller to see result

imax = 1
imin = 0
ichan = 1 
ictlno = 7

        initc21 1, ictlno, ictlno+1, ictlno+2. 1                        ; start at max. volume
kamp    ctrl21  ichan, ictlno, ictlno+1, ictlno+2, imin, imax   ; controller 7
        printk2 kamp
asig    oscil   kamp, 220, 1
        outs    asig, asig

endin

</CsInstruments>
<CsScore>
f 1 0 4096 10 1

i1 0 20

e
</CsScore>
</CsoundSynthesizer>

See also

MIDI input and Initialization

Credits

Author: Gabriel Maldonado
Italy

New in Csound version 3.47

Thanks goes to Rasmus Ekman for pointing out the correct MIDI channel and controller number ranges.