User Manual

Core Avid Audio Plug-Ins
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The following table lists the Time Compression Expansion plug-in parameters.
Parameter Description
Source and
Destination
The Source text boxes display the length of the current selection before processing in each of
the listed formats. All the text boxes in both columns update dynamically, so a change made
to one value is immediately reflected in the values displayed in the other text boxes.
The text boxes in the Destination column display and control the length of the selection after
processing using the current settings. You can enter the length of the Destination file by
double-clicking the appropriate text box in the Destination column. Type the number of
samples in min:secs:msec format or type timecode values as start and end locations. All the
Destination text boxes update dynamically, so a change made to one value is immediately
reflected in the values displayed in the other text boxes.
You can also enter a new tempo, bars:beats:ticks length, or time signature for regions that
have tempo or Bars & Beats settings. This can be any region associated with a MIDI
Metronome value (such as an overdub recorded to a MIDI click) or regions that have been
processed with the Pro Tools Identify Beat command.
The Ratio slider lets you set the destination length in relation to the source length. Dragging
the slider to the right increases the length of the destination file, and dragging the slider to
the left decreases its length.
The controls below the bar line lets you fine-tune the time compression and expansion
process. They include the Crossfade, Min Pitch, and Accuracy sliders.
Crossfade The Crossfade slider lets you manually adjust the crossfade length in milliseconds to
optimize performance of the Time Compression Expansion plug-in according to the type of
audio material you process. The Time Compression Expansion plug-in achieves length
modification by replicating or subtracting very small portions of audio material and very
quickly crossfading between these alterations in the waveform of the audio material.
Crossfade length essentially affects the amount of smoothing performed on audio material to
prevent audio artifacts such as clicks. In general, small narrow-range time (length) changes
require longer crossfades while larger changes in length require shorter crossfades. The
disadvantage of long crossfade times is that they smooth the signal, including any transients.
While this can be desirable for audio material such as vocals, it is not appropriate for
material with sharp transients such as drums or percussion.
The default setting for this parameter is Auto (leftmost position), in which crossfade times
are set automatically according to the percentage of change in length for the current process.
This setting should suffice for most applications, but you can use this slider to manually
adjust and optimize crossfade times, if necessary. For audio material with sharper attack
transients, use shorter crossfade times. For audio material with softer attack transients, use
longer crossfade times with a range in values of 1 to 200 ms.