Stretching Time And Pitch - CAKEWALK PRO AUDIO User Manual

Stretching Time and Pitch

The Cakewalk FX Time/Pitch Stretch command lengthens or
shortens audio data, and raises or lowers pitch. Time and pitch can be
stretched independently. You can use this effect to stretch or compress
audio while preserving pitch, or to change pitch while preserving
duration, or both. The time/pitch stretch parameters are as follows:
Parameter/Option... Meaning...
Time (%) The new length of the audio event, as a percentage
of the length of the original event.
Pitch The amount by which the pitch is changed, in
semitones.
Source Material The type of audio data. Selecting an option sets
recommended values for the Block Rate, Overlap
Ratio, Crossfade Ratio, Accuracy, and Algorithm
parameters.
Block Rate (Hz) Used to calculate the size of the data "blocks"
processed by Time/Pitch Stretch. Lower values lead
to larger block sizes. If the material to be processed
is generally less percussive or lower in pitch, using a
lower block rate will make the algorithm operate
more efficiently.
Overlap Ratio The amount of overlap between consecutive blocks.
Crossfade Ratio The crossfade amount for the blocks.
Accuracy The accuracy of the calculations. Normal is good for
most sounds. High accuracy gives slightly better
quality, but takes longer to process.
Algorithm The algorithm used for pitch stretching. The Normal
algorithm is used in most circumstances, but causes
a "chipmunk effect" on vocals. Use the Formant-
Preserving algorithm to help retain the natural
quality of vocals.
The Time and Pitch parameters can be set by typing numbers in the
appropriate boxes, or by dragging the sliders or the crosshair in the
graph. Holding Shift while dragging the crosshair snaps the crosshair to
the nearest axis: X (time), Y (pitch), or the diagonal (equal time and
pitch). Diagonal values on the graph can be processed very quickly and
with very high quality, but have the trade-off that changing pitch does
not preserve duration, and vice versa.
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