an open-source digital signal processing and sound synthesis language
about · links · contact
REV -- several basic reverberators
in RTcmix/insts/jg

quick syntax:
REV(outsk, insk, dur, AMP, rvbtype, rvbtime, RVBAMT[, inputchan])

CAPITALIZED parameters are pfield-enabled for table or dynamic control (see the maketable or makeconnection scorefile commands). Parameters after the [bracket] are optional and default to 0 unless otherwise noted.

   p0 = output start time (seconds)
   p1 = input start time (seconds)
   p2 = input duration (seconds)
   p3 = amplitude multiplier (relative multiplier of input signal)
   p4 = reverb type (integer, use  1: PRCRev, 2: JCRev, 3: NRev; see Usage Notes below)
   p5 = reverb time (seconds)
   p6 = reverb amount (0: dry --> 1: wet)
   p7 = input channel  [optional; default is 0]

   p3 (amplitude) and p6 (reverb amount) can receive dynamic updates from
   a table or real-time control source.

   Author:  John Gibson, 7/19/99; rev for v4, 7/21/04
   based on several reverberators from the STK package (by Perry Cook, Gary Scavone, and Tim Stilson)

REV processes input audio through a choice of three different reverb types (all from CCRMA st Stanford University).

Usage Notes

The reverberators in REV all have characteristic 'sounds', for more general reverberation the FREEVERB or GVERB instruments are probably better. There are also a number of excellent room-simulator instruments (listed under the See Also section below). The REV algorithms are very efficient, though.

The reverb types are:

     (1) PRCRev (Perry R. Cook)
           2 allpass units in series followed by 2 comb filters in parallel.

     (2) JCRev (John Chowning)
           3 allpass filters in series, followed by 4 comb filters in
           parallel, a lowpass filter, and two decorrelation delay lines
           in parallel at the output.

     (3) NRev (Michael McNabb)
           6 comb filters in parallel, followed by 3 allpass filters, a
           lowpass filter, and another allpass in series, followed by 2
           allpass filters in parallel with corresponding right and left

REV can produce either mono or stereo output.

Sample Scores

very basic:
   rtsetparams(44100, 2)

   outskip = 0
   inskip = 0
   dur = DUR()
   amp = 0.7
   rvbtype = 3
   rvbtime = 0.3
   rvbpct = 0.3
   inchan = 0

   ampenv = maketable("line", 1000, 0,0, 1,1, dur-1,1, dur,0)

   REV(outskip, inskip, dur, amp*ampenv, rvbtype, rvbtime, rvbpct, inchan)

See Also