CCRMA

Granular Synthesis and Sampling Rate Conversion


Lecture Slides

A series of gif images of the lecture slides... (only accesible from within Stanford University)


Granular Synthesis

Overview of granular synthesis techniques.


Examples

Here's a simple granular synthesis instrument in clm (grani.ins).

Here is the header of the instrument and a short description of its parameters:

(definstrument grani (start-time duration amplitude file
		      &key
		      (amp-envelope '(0 0.3 1 0.7 1 1 0))
		      (grain-envelope '(0 0 0.3 1 0.7 1 1 0))
		      (grain-duration 0.1)
		      (grain-hop 0.2)
		      (grain-hop-spread 0.05)
		      (in-file-srate 1.0)
		      (in-file-start 0)
		      (in-file-hop 0.2)
		      (in-file-hop-spread 0.05)
		      (degree 45)
		      (distance 1)
		      (reverb-amount 0.01))

Mandatory parameters

start-time
starting time in seconds
duration
duration of the note in seconds
amplitude
amplitude of the note
file
the complete pathname of the soundfile you want to use as source material

Optional parameters

amp-envelope
amplitude envelope for the whole note
grain-envelope
amplitude envelope for an individual grain
grain-duration
duration of each individual grain
grain-hop
distance in seconds between grains (can be smaller than the grain-duration)
grain-hop-spread
maximum random component in seconds added to the grain-hop
in-file-srate
sample rate conversion factor for the input file
in-file-start
position in seconds in the input file where to start getting samples
in-file-hop
distance in seconds between starts of grains in the input file
in-file-hop-spread
random component added to the distance in seconds between starts of grains
degree
angle in degrees from where the sound is coming from in a stereo rendition. "0" is left and "90" is right; "45" is right in the middle of the stereo field.
distance
distance in feet from where the sound is coming from.
reverb-amount
amount of reverberation added to the sound. For this to work you must have a reverberator loaded and the with-sound call has to specify it.
Some examples...


Here's the "one-cut" instrument, a soundfile mangling machine... (cut.ins). Here are some parameter examples you can paste into a with-sound.

To probe further

Use the "grani" granular synthesis instrument for processing (ie: mangling) input soundfiles. Create some interesting transformations on the input. Make soundfiles sing and or sttttttutttter. There are some soundfiles available for use (or you can roll your own). You can find a small gong in "/Web/Info/CCRMA/Courses/SoundSynthesis/Lectures/4/Sounds/small-gong.snd", a small cowbell in the same directory, file name "cencerros-1.snd", a cymball and a tubular bell... Have fun!


©1997 Fernando Lopez-Lezcano. All Rights Reserved.
nando@ccrma.stanford.edu