CAST Transforms: Transpose

revised 2/3/98

Introduction

The frequencies of all partials are multiplied by the "scale_freq" parameter, thus transposing. This form of transposition shifts the spectral envelope of the sound as you transpose, giving the same "darth vader" and "munchkin" timbral effects as varying the speed of playback of a tape or pitch-shifting a sample.

The transposition amount has no effect on the rate at which the voice moves through a timbral prototype.

Parameters

Message Argument(s) Type(s) Description
scale_freq Frequency scale factor  Float The frequency of each partial is multiplied by this factor.

 

Examples

For the following examples run demosoftcast -voices 2 /usr/local/cast/lib/data/coleman/lick1.fmt.

The identity transform:

/voices/0/transpose/scale_freq 1.0
/voices/0/tm/goto 0.0

One octave up:

/voices/0/transpose/scale_freq 2.0 0
/voices/0/tm/goto 0.0

One octave down:

/voices/0/transpose/scale_freq 0.5
/voices/0/tm/goto 0.0

One fifth up:

/voices/0/transpose/scale_freq 1.5
/voices/0/tm/goto 0.0

One fifth down:

/voices/0/transpose/scale_freq 0.6666667
/voices/0/tm/goto 0.0