nchnls_hw — Returns the number of audio channels in the underlying hardware.


Returns the maximum number of audio channels in the underlying hardware. This does not necessarily correspond to the number of channels used by Csound (set by nchnls and nchnls_i).


idacc,iadcc nchnls_hw


On init-pass idacc will contain the number of channels in the output device, and iadcc, the number of input channels. These will correspond to the currently selected/in-use hardware devices.


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

Example 670. Example of the nchnls_hw 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 ;;;realtime audio out
-iadc    ;;;realtime audio in
; by Menno Knevel - 2024
sr = 44100
ksmps = 32
nchnls = 2
0dbfs  = 1

instr 1 

idacc,iadcc nchnls_hw
prints "\non this machine:"
prints "\nnumber of outputs = %d\n", idacc
prints  "number of inputs = %d\n\n", iadcc


i1 0 0

The output should include lines like these:

on this machine:
number of outputs = 32
number of inputs = 32

See also

Miscellaneous opcodes


Author: Victor Lazzarini

In version 6.07