an open-source digital signal processing and sound synthesis language
about · links · contact
STGRANR -- sampling stochastic granular processor
in RTcmix/insts/std/MARAGRAN


quick syntax:
STGRANR(outsk, insk, dur, amp, rate, p5-8: ratevar, p9-12: duration, p13-16: location, p17-20: transposition[, grainlayers (not used), seed])
    This instrument has no pfield-enabled parameters. Parameters after the [bracket] are optional and default to 0 unless otherwise noted.


   p0 = output start time (seconds)
   p1 = input start time (seconds)
   p2 = duration (seconds)
   p3 = amplitude multiplier (relative multiplier of input signal)
   p4 = grain rate (seconds)
   p5-8 = rate variance (between 0.0 and 1.0; it is the % variation in rate - 100% being the rate)
   p9-12 = duration values (seconds)
   p13-16 = location values (0-1 stereo; 0.5 is middle)
   p17-20 = transposition values
   p21 = grainlayers [optional; default is 0]
   p22 = random number seed [optional; default is 0]

   Because this instrument has not been updated for pfield control,
   the older makegen control envelope sysystem should be used:

   assumes function table 1 is the amplitude envelope
   function table 2 is the synthesis waveform,
   function table 3 is grain amplitude envelope

   Parameters after the [bracket] are optional and default to 0 unless
   otherwise noted.

   Author: Mara Helmuth (mara dot helmuth at uc dot edu)



STGRANR does stochastic granular signal-processing, decomposing an input soundfile or real-time sound source. It's a fairly powerful instrument, with lots of snazzy gen-envelope controls to produce evolving granular textures. To best understand the concepts behind the design of this instrument, see Mara Helmth's papers on the use of these techniques.

It was originally adapted from the older stgran Cmix instrument, also written by Mara.

Usage Notes

At present the setting of the buffer size in rtsetparams appears to have a significant effect on the output of this instrument.

STGRANR will take mono or stereo input files, it requires stereo output.

Sample Scores

very basic:
   set_option("FULL_DUPLEX_ON")
   rtsetparams(44100, 2)
   load("STGRANR")

   rtinput("AUDIO","MIC",2)

   makegen(1, 7, 1000, 1, 950, 1, 50, 0)
   makegen(2, 25, 1000, 1)

   start = 0.0

   /* p0start, p1inputstt, p2dur, p3amp */
   STGRANR(start, 0, 13, 5000, 
   /* grain rate, ratevar values (must be positive,
      % until next grain possible displacement): */
   .1, 0.0, 0.1, 0.2, 1.0,
   /* duration values: */
   .1,.1,.1,2, 
   /* location values: */
   0.0,0.5,1.0,10.0, 
   /* pitch values: */
   0.0,0.00,0.07,2,
   /* granlyrs, seed */
   1,1)


See Also

GRANSYNTH, GRANULATE, JCHOR, JGRAN, SGRANR