ftchnls — Returns the number of channels in a stored function table.
Returns the number of channels of a GEN01 table, determined from the header of the original file. If the original file has no header or the table was not created by these GEN01, ftchnls returns -1.
Here is an example of the ftchnls opcode. It uses the file ftchnls.csd, and mary.wav.
Example 169. Example of the ftchnls 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 ; Audio out Audio in -odac -iadc ;;;RT audio I/O ; For Non-realtime ouput leave only the line below: ; -o ftchnls.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> ; Initialize the global variables. sr = 44100 kr = 4410 ksmps = 10 nchnls = 1 ; Instrument #1. instr 1 ; Print out the number of channels in Table #1. ichnls = ftchnls(1) print ichnls endin </CsInstruments> <CsScore> ; Table #1: Use an audio file, Csound will determine its size. f 1 0 0 1 "mary.wav" 0 0 0 ; Play Instrument #1 for 1 second. i 1 0 1 e </CsScore> </CsoundSynthesizer>
Since the audio file “mary.wav” is monophonic (1 channel), its output should include a line like this:
instr 1: ichnls = 1.000