Description

midipitchbend is designed to simplify writing instruments that can be used interchangeably for either score or MIDI input, and to make it easier to adapt instruments originally written for score input to work with MIDI input.

In general, it should be possible to write instrument definitions that work identically with both scores and MIDI, including both MIDI files and real-time MIDI input, without using any conditional statements, and that take full advantage of MIDI voice messages.

Note that correlating Csound instruments with MIDI channel numbers is done using the massign opcode for real-time performance,. For file-driven performance, instrument numbers default to MIDI channel number + 1, but the defaults are overridden by any MIDI program change messages in the file.

Syntax

midipitchbend xpitchbend [, ilow] [, ihigh]

Initialization

ilow (optional) -- optional low value after rescaling, defaults to 0.

ihigh (optional) -- optional high value after rescaling, defaults to 127.

Performance

xpitchbend -- returns the MIDI pitch bend during MIDI activation, remains unchanged otherwise.

If the instrument was activated by MIDI input, the opcode overwrites the value of xpitchbend with the corresponding value from MIDI input. If the instrument was NOT activated by MIDI input, the value of xpitchbend remains unchanged.

This enables score p-fields to receive MIDI input data during MIDI activation, and score values otherwise.

	Adapting a score-activated Csound instrument.
	See the MIDI interop opcodes section for details on adapting score driven instruments for MIDI or vice-versa.

Examples

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

<CsoundSynthesizer>
<CsOptions>
; Select audio/midi flags here according to platform
-odac    -M1  ;;;realtime audio out and midi in 
;-iadc    ;;;uncomment -iadc if realtime audio input is needed too
; For Non-realtime ouput leave only the line below:
; -o midipitchbend.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

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

instr 1

midinoteonoct p4, p5				;gets a MIDI note number value as octave-point-decimal value into p4, and MIDI velocity into p5

kvel = p5/127					;scale midi velocity to 0-1
kpb init 0
midipitchbend kpb
printk2 kpb					;display the pitch-bend value when it changes
koct =	p4+kpb					;add pitchbend values to octave-point-decimal value
kcps =	cpsoct(koct)				;convert octave-point-decimal value into Hz			
kenv madsr 0.5, 0.8, 0.8, 0.5			;amplitude envelope multiplied by
asig vco2 kenv*kvel, kcps			;velocity value			
     outs  asig, asig				

endin
</CsInstruments>
<CsScore>
f 0 30	;runs for 30 seconds
f 2 0 4096 10 1	

i 1 0 2 8.000 100	; play these notes from score as well
i 1 + 2 8.917 100
e

</CsScore>
</CsoundSynthesizer>

Its output should include lines like:

 i1     0.12695
 i1     0.00000
 i1    -0.01562
      

See Also

midichannelaftertouch, midicontrolchange, mididefault, midinoteoff, midinoteoncps, midinoteonkey, midinoteonoct, midinoteonpch, midipolyaftertouch, midiprogramchange

Credits

Author: Michael Gogins

New in version 4.20