xtratim — Extend the duration of real-time generated events.
Extend the duration of real-time generated events and handle their extra life (Usually for usage along with release instead of linenr, linsegr, etc).
xtratim extends current MIDI-activated note duration by iextradur seconds after the corresponding noteoff message has deactivated the current note itself. It is usually used in conjunction with release. This opcode has no output arguments.
This opcode is useful for implementing complex release-oriented envelopes, whose duration is not known when the envelope starts (e.g. for real-time MIDI generated events).
Here is a simple example of the xtratim opcode. It uses the file xtratim.csd.
Example 1062. Example of the xtratim opcode.
See the sections Real-time Audio and Command Line Flags for more information on using command line flags.
This example shows how to generate a release segment for an ADSR envelope after a MIDI noteoff is received, extending the duration with xtratim and using release to check whether the note is on the release phase.
<CsoundSynthesizer> <CsOptions> ; Select audio/midi flags here according to platform ; Audio out Audio in Silent MIDI in -odac -iadc -d -M0 ;;;realtime I/O </CsOptions> <CsInstruments> ;Simple usage of the xtratim opcode sr = 44100 ksmps = 10 nchnls = 2 ; sine wave for oscillators gisin ftgen 1, 0, 4096, 10, 1 instr 1 inum notnum icps cpsmidi iamp ampmidi 4000 ; ;------- complex envelope block ------ xtratim 1 ;extra-time, i.e. release dur krel init 0 krel release ;outputs release-stage flag (0 or 1 values) if (krel == 1) kgoto rel ;if in release-stage goto release section ; ;************ attack and sustain section *********** kmp1 linseg 0, .03, 1, .05, 1, .07, 0, .08, .5, 4, 1, 50, 1 kmp = kmp1*iamp kgoto done ; ;--------- release section -------- rel: kmp2 linseg 1, .3, .2, .7, 0 kmp = kmp1*kmp2*iamp done: ;------ a1 oscili kmp, icps, gisin outs a1, a1 endin </CsInstruments> <CsScore> f 0 3600 ;dummy table to wait for realtime MIDI events e </CsScore> </CsoundSynthesizer>
Here is a more elaborate example of the xtratim opcode. It uses the file xtratim-2.csd.
Example 1063. More complex example of the xtratim opcode.
This example shows how to generate a release segment for an ADSR envelope after a MIDI noteoff is received, extending the duration with xtratim and using release to check whether the note is on the release phase. Two envelopes are generated simultaneously for the left and right channels.
<CsoundSynthesizer> <CsOptions> ; Select audio/midi flags here according to platform ; Audio out Audio in Silent MIDI in -odac -iadc -d -M0 ;;;realtime I/O </CsOptions> <CsInstruments> ;xtratim example by Jonathan Murphy Dec. 2006 sr = 44100 ksmps = 10 nchnls = 2 ; sine wave for oscillators gisin ftgen 1, 0, 4096, 10, 1 ; set volume initially to midpoint ctrlinit 1, 7,64 ;;; simple two oscil, two envelope synth instr 1 ; frequency kcps cpsmidib ; initial velocity (noteon) ivel veloc ; master volume kamp ctrl7 1, 7, 0, 127 kamp = kamp * ivel ; parameters for aenv1 iatt1 = 0.03 idec1 = 1 isus1 = 0.25 irel1 = 1 ; parameters for aenv2 iatt2 = 0.06 idec2 = 2 isus2 = 0.5 irel2 = 2 ; extra (release) time allocated xtratim (irel1>irel2 ? irel1 : irel2) ; krel is used to trigger envelope release krel init 0 krel release ; if noteoff received, krel == 1, otherwise krel == 0 if (krel == 1) kgoto rel ; attack, decay, sustain segments atmp1 linseg 0, iatt1, 1, idec1, isus1 , 1, isus1 atmp2 linseg 0, iatt2, 1, idec2, isus2 , 1, isus2 aenv1 = atmp1 aenv2 = atmp2 kgoto done ; release segment rel: atmp3 linseg 1, irel1, 0, 1, 0 atmp4 linseg 1, irel2, 0, 1, 0 aenv1 = atmp1 * atmp3 ;to go from the current value (in case aenv2 = atmp2 * atmp4 ;the attack hasn't finished) to the release. ; control oscillator amplitude using envelopes done: aosc1 oscil aenv1, kcps, gisin aosc2 oscil aenv2, kcps * 1.5, gisin aosc1 = aosc1 * kamp aosc2 = aosc2 * kamp ; send aosc1 to left channel, aosc2 to right, ; release times are noticably different outs aosc1, aosc2 endin </CsInstruments> <CsScore> f 0 3600 ;dummy table to wait for realtime MIDI events </CsScore> </CsoundSynthesizer>