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ctrl7

Allows a floating-point 7-bit MIDI signal scaled with a minimum and a maximum range.

Syntax

idest ctrl7 ichan, ictlno, imin, imax [, ifn]
kdest ctrl7 ichan, ictlno, kmin, kmax [, ifn]
adest ctrl7 ichan, ictlno, kmin, kmax [, ifn] [, icutoff]

Initialization

idest -- output signal

ichan -- MIDI channel (1-16)

ictlno -- MIDI 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.

icutoff (optional) -- low pass filter cut-off frequency for smoothing a-rate output.

Performance

kdest, adest -- output signal

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

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

ctrl7 (i- and k-rate 7 bit MIDI control) allows a floating-point 7-bit MIDI signal scaled with a minimum and a maximum range. It also allows optional non-interpolated table indexing. Minimum and maximum values can be varied at k-rate.

ctrl7 differs from midic7 because it can be included in score-oriented instruments without Csound crashes. It also needs the additional parameter ichan containing the MIDI channel of the controller.

The a-rate version of ctrl7 outputs an a-rate variable, which is low-pass filtered (smoothed). It contains an optional icutoff parameter, to set the cutoff frecuency for the low-pass filter. The default is 5.

Examples

Here is an example of the ctrl7 opcode. It uses the file ctrl7.csd.

Example of the ctrl7 opcode.
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<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

        initc7  1, 7, 1                 ; start at max. volume
kamp    ctrl7   ichan, ictlno, 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>

📝 Note

ctrl7 only outputs k values once the controller is first moved. To set an initial k-value, a call to initc7 is required. Ctrlinit does not work for this purpose.

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.

The a-rate version of ctrl7 was added in version 5.06