mxadsr

mxadsr — Calculates the classical ADSR envelope using the expsegr mechanism.

Description

Calculates the classical ADSR envelope using the expsegr mechanism.

Syntax

ares mxadsr iatt, idec, islev, irel [, idel] [, ireltim]
kres mxadsr iatt, idec, islev, irel [, idel] [, ireltim]

Initialization

iatt -- duration of attack phase

idec -- duration of decay

islev -- level for sustain phase

irel -- duration of release phase

idel (optional, default=0) -- period of zero before the envelope starts

ireltim (optional, default=-1) -- Control release time after receiving a MIDI noteoff event. If less than zero, the longest release time given in the current instrument is used. If zero or more, the given value will be used for release time. Its default value is -1. (New in Csound 3.59 - not yet properly tested)

Performance

The envelope is in the range 0 to 1 and may need to be scaled further. The envelope may be described as:

Picture of an ADSR envelope.

Picture of an ADSR envelope.

The length of the sustain is calculated from the length of the note. This means adsr is not suitable for use with MIDI events. The opcode madsr uses the linsegr mechanism, and so can be used in MIDI applications. The opcode mxadsr is identical to madsr except it uses exponential, rather than linear, line segments.

You can use other pre-made envelopes which start a release segment upon recieving a note off message, like linsegr and expsegr, or you can construct more complex envelopes using xtratim and release. Note that you don't need to use xtratim if you are using mxadsr, since the time is extended automatically.

mxadsr is new in Csound version 3.51.

Examples

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

Example 518. Example of the mxadsr 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  -+rtmidi=virtual -M0   ;;;realtime audio out and realtime midi in
;-iadc    ;;;uncomment -iadc if realtime audio input is needed too
; For Non-realtime ouput leave only the line below:
; -o mxadsr.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

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

instr 1
 	 
icps	cpsmidi	 	 
iamp	ampmidi	.5	 
 	 	 	 
kenv	mxadsr	0.5, 0, 1, 0.5
asig	pluck	kenv, icps, icps, 2, 1	 
	outs	asig, asig
	 
endin
</CsInstruments>
<CsScore>
f 2 0 4096 10 1	

f0 30	;runs 30 seconds
e
</CsScore>
</CsoundSynthesizer>


See Also

linsegr, expsegr, envlpxr, mxadsr, madsr, adsr, expon, expseg, expsega line, linseg, xtratim

Credits

Author: John ffitch

November 2002. Thanks to Rasmus Ekman, added documentation for the ireltim parameter.

November 2003. Thanks to Kanata Motohashi, fixed the link to the linsegr opcode.