midichn

midichn — Returns the MIDI channel number from which the note was activated.

Description

midichn returns the MIDI channel number (1 - 16) from which the note was activated. In the case of score notes, it returns 0.

Syntax

ichn midichn

Initialization

ichn -- channel number. If the current note was activated from score, it is set to zero.

Examples

Here is a simple example of the midichn opcode. It uses the file midichn.csd.

Example 472. 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
-odac -M0 -+rtmidi=virtual ;;; midi file input
</CsOptions>
<CsInstruments>

sr = 44100
ksmps = 32
nchnls = 2
0dbfs  = 1

instr 1	 
;change channel on virtual midi keyboard
i1 midichn
   print i1

endin
</CsInstruments>
<CsScore>
f 0 20	;runs for 20 seconds

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 473. An advanced example of the midichn opcode.

<CsoundSynthesizer>
<CsOptions>
; Select audio/midi flags here according to platform
-odac -F midichn_advanced.mid ;;;realtime audio out with MIDI file input
; For Non-realtime ouput leave only the line below:
; -o midichn_advanced.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

sr = 44100
ksmps = 32
nchnls = 2
0dbfs  = 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:

icps	cpsmidi		; convert midi note to pitch
kenv	madsr	0.1, 0, 0.8, 0.9
asig	pluck	kenv, icps, icps, 1, 1	 
	outs	asig, asig
	 
endin
</CsInstruments>
<CsScore>
t 0 60		;beats per minute

f 0 8		;stay active for 8 seconds
f 1 0 4096 10 1	;sine

e
</CsScore>
</CsoundSynthesizer>


Its output should include lines like:

note 1 (time = 0.00) was activated from channel 1
note 2 (time = 2.00) was activated from channel 4
note 3 (time = 3.00) was activated from channel 2
note 4 (time = 5.00) was activated from channel 3
      

See Also

pgmassign

Credits

Author: Istvan Varga
May 2002

New in version 4.20