WaveWarp 2.0 Component
      
Playback Controllers:
Controllable Playback Speed Controller
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Functional Description
Varies the rate at which an audio file is played by an arbitrary (non-integer) factor,
dynamically controllable via the control signal input.
IMPORTANT:
This specialised component is intended for use in conjunction with
a
Controllable Input Audio File
(refer to the corresponding on-line help for
for a detailed description of WaveWarp's controllable playback functionality).
In order to implement the controllable playback,
the control input to this component can be an arbitrary
time-varying control signal (containing the desired time-history of playback rate factors)
but
the output control signal
should be connected to the control input of a
Controllable Input Audio file.
NOTE: This component is identical in function to the
Playback Speed Controller
except that the playback speed is selected dynamically via the control input,
rather than via the Parameter Window.
Algorithm
The control signal ouput consists of a sequence of integers which, when used to control
the instantaneous playback step-size of an audio file, results in the file being played
(on average) at the chosen rate (as set by the input control signal).
For example, if the chosen playback rate factor
happens to be 1.1 (i.e. the input control signal happens to be constant at 1.1),
the output integer sequence will consist of a string of "1"s (normal playback), with a "2" inserted
at every 10th site (instructing the playback engine to skip a sample), thereby
skipping every 10th sample, such that the file is played, on average, 10% faster, as desired.
Likewise,
if the chosen playback rate factor
happens to be 0.9 (i.e. the input control signal happens to be constant at 0.9),
the output integer sequence will consist of a string of "1"s (normal playback), with a "0" inserted
at every 10th site (instructing the playback engine to repeat a sample),
thereby repeating every 10th sample, such that the file is played, on average, 10% slower,
as desired. Negative playback factors (i.e. file reversal) are implemented in the same manner,
though using negative values in the output integer sequence.
Signal Implementations
| Audio signals | Control signals | Description |
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| n/a | Single input single output |
Input can be an arbitrary control signal; output should be connected to the input of a
Controllable Input Audio file.
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Related components:
Example DrawingBoards illustrating usage:
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