midichn — Returns the MIDI channel number from which the note was activated.
midichn returns the MIDI channel number (1 - 16) from which the note was activated. In the case of score notes, it returns 0.
ichn -- channel number. If the current note was activated from score, it is set to zero.
Here is a simple example of the midichn opcode. It uses the file midichn.csd.
Example 252. Example of the midichn 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 No messages MIDI in -odac -iadc -d -M0 ;;;RT audio I/O with MIDI in ; For Non-realtime ouput leave only the line below: ; -o midichn.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 i1 midichn print i1 endin </CsInstruments> <CsScore> ; Play Instrument #1 for 12 seconds. i 1 0 12 e </CsScore> </CsoundSynthesizer>
Here is an advanced example of the midichn opcode. It uses the file midichn_advanced.csd.
Don't forget that you must include the -F flag when using an external MIDI file like “midichn_advanced.mid”.
Example 253. An advanced example of the midichn opcode.
<CsoundSynthesizer> <CsOptions> ; Select audio/midi flags here according to platform ; Audio out Audio in No messages MIDI in -odac -iadc -d -M0 ;;;RT audio I/O with MIDI in ; For Non-realtime ouput leave only the line below: ; -o midichn_advanced.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> sr = 44100 ksmps = 10 nchnls = 1 massign 1, 1 ; all channels use instr 1 massign 2, 1 massign 3, 1 massign 4, 1 massign 5, 1 massign 6, 1 massign 7, 1 massign 8, 1 massign 9, 1 massign 10, 1 massign 11, 1 massign 12, 1 massign 13, 1 massign 14, 1 massign 15, 1 massign 16, 1 gicnt = 0 ; note counter instr 1 gicnt = gicnt + 1 ; update note counter kcnt init gicnt ; copy to local variable ichn midichn ; get channel number istime times ; note-on time if (ichn > 0.5) goto l2 ; MIDI note printks "note %.0f (time = %.2f) was activated from the score\\n", \ 3600, kcnt, istime goto l1 l2: printks "note %.0f (time = %.2f) was activated from channel %.0f\\n", \ 3600, kcnt, istime, ichn l1: endin </CsInstruments> <CsScore> t 0 60 f 0 6 2 -2 0 i 1 1 0.5 i 1 4 0.5 e </CsScore> </CsoundSynthesizer>
Its output should include lines like:
note 7 (time = 0.00) was activated from channel 4
note 8 (time = 0.00) was activated from channel 2