I just committed a new effect called "Auto Duck". This effect can be
used to automatically "duck" the volume of the selected tracks as soon
as another track (the "control track") exceeds a configurable volume. It
can be used to create voice-overs for DJ sets, but also for automatic
ramping of the talk bed (background music) in radio productions.
Translators can use it to ramp down the original voice as soon as the
translation kicks in.
To apply the effect, select the tracks which should be changed
("auto-ducked") and place the control track exactly below the last
selected track. Then choose "Auto Duck" from the effect menu.
The following parameters can be configured, some of them graphically:
* Duck Amount: The amount the volume should be reduced when a signal is
detected (default: -12db)
* Fade Down Length: Time used to fade down the volume (default: 0.5s)
* Fade Up Length: Time used to fade up the volume (default: 0.5s)
* Maximum Pause: Avoid "pumping" by entering a maximum pause that must
be exceeded until the volume is ramped up again. Even without this
setting, the effect will only ramp up when the pause is at least (fade
down length + fade up length) long.
* Threshold: Threshold for detecting if the control track has a signal
Everything has been coded and tested on Linux. I'll try to test it on
Windows too, as time permits.
I hope you like it. Comments highly welcome!