vcomb — Variably reverberates an input signal with a “colored” frequency response.
imaxlpt -- maximum loop time for klpt
iskip (optional, default=0) -- initial disposition of delay-loop data space (cf. reson). The default value is 0.
insmps (optional, default=0) -- delay amount, as a number of samples.
krvt -- the reverberation time (defined as the time in seconds for a signal to decay to 1/1000, or 60dB down from its original amplitude).
xlpt -- variable loop time in seconds, same as ilpt in comb. Loop time can be as large as imaxlpt.
This filter reiterates input with an echo density determined by loop time xlpt. The attenuation rate is independent and is determined by krvt, the reverberation time (defined as the time in seconds for a signal to decay to 1/1000, or 60dB down from its original amplitude). Output will appear only after ilpt seconds.
Here is an example of the vcomb opcode. It uses the file vcomb.csd.
Example 986. Example of the vcomb 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 -odac -iadc -M0 ;;;RT audio I/O with MIDI in </CsOptions> <CsInstruments> ; Example by Jonathan Murphy and Charles Gran 2007 sr = 44100 ksmps = 10 nchnls = 2 ; new, and important. Make sure that midi note events are only ; received by instruments that actually need them. ; turn default midi routing off massign 0, 0 ; route note events on channel 1 to instr 1 massign 1, 1 ; Define your midi controllers #define C1 #21# #define C2 #22# #define C3 #23# ; Initialize MIDI controllers initc7 1, $C1, 0.5 ;delay send initc7 1, $C2, 0.5 ;delay: time to zero initc7 1, $C3, 0.5 ;delay: rate gaosc init 0 ; Define an opcode to "smooth" the MIDI controller signal opcode smooth, k, k kin xin kport linseg 0, 0.0001, 0.01, 1, 0.01 kin portk kin, kport xout kin endop instr 1 ; Generate a sine wave at the frequency of the MIDI note that triggered the intrument ifqc cpsmidi iamp ampmidi 10000 aenv linenr iamp, .01, .1, .01 ;envelope a1 oscil aenv, ifqc, 1 ; All sound goes to the global variable gaosc gaosc = gaosc + a1 endin instr 198 ; ECHO kcmbsnd ctrl7 1, $C1, 0, 1 ;delay send ktime ctrl7 1, $C2, 0.01, 6 ;time loop fades out kloop ctrl7 1, $C3, 0.01, 1 ;loop speed ; Receive MIDI controller values and then smooth them kcmbsnd smooth kcmbsnd ktime smooth ktime kloop smooth kloop imaxlpt = 1 ;max loop time ; Create a variable reverberation (delay) of the gaosc signal acomb vcomb gaosc, ktime, kloop, imaxlpt, 1 aout = (acomb * kcmbsnd) + gaosc * (1 - kcmbsnd) outs aout, aout gaosc = 0 endin </CsInstruments> <CsScore> f1 0 16384 10 1 i198 0 10000 e </CsScore> </CsoundSynthesizer>