filenchnls — Returns the number of channels in a sound file.
ifilcod -- sound file to be queried
iallowraw -- (Optional) Allow raw sound files (default=1)
filenchnls returns the number of channels in the sound file ifilcod. filechnls can return the number of channels of convolve and PVOC files if the iallowraw flag is not zero (it is non-zero by default).
Here is an example of the filenchnls opcode. It uses the file filenchnls.csd, fox.wav, and drumsSlp.wav.
Example 297. Example of the filenchnls opcode.
See the sections Real-time Audio and Command Line Flags for more information on using command line flags.
<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 filenchnls.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> sr = 44100 ksmps = 32 nchnls = 2 0dbfs = 1 ; by Menno Knevel 2022 instr 1 ; choose between mono or stereo file ichn filenchnls p4 ; check number of channels prints "\nnumber of channels = %d\n\n", ichn if (ichn == 1) then asig diskin2 p4, 1 ; mono signal outs asig, asig else aL, aR diskin2 p4, 1 ; stereo signal outs aL, aR endif endin </CsInstruments> <CsScore> i 1 0 3 "fox.wav" ;mono signal i 1 5 4 "drumsSlp.wav" ;stereo signal e </CsScore> </CsoundSynthesizer>
The audio file “fox.wav” is monoaural (1 channel), while “drumsSlp.wav” is stereo (2 channels) So filenchnls's output should include lines like this:
number of channels = 1
number of channels = 2