Trace Envelope

[swbaz]

Hi there,
I'm new to Audacity but am a long time pro in studio technology and recording. Yea, must have had my head in the sand!
I really love the interface you guys have created and have had some fun exploring the effects menu. I have a suggestion though.
Years ago I owned a program called Alchemy. It had what I think they called a "trace envelope" control.
You could select any wave form and make a copy of its volume change over time.
You could then paste this over another wave form making its envelope behave in exactly the same way.
Why I have never seen this feature in any other editor since, is beyond me.
It would be great if you guys could add this feature to Audacity. Taking it further, you could do the same thing with frequencies. Very cool !
Thanks for listening.

[steve]

Someone asked about a similar (the same?) thing about 3 1/2 years ago. There has not been any substantial demand for such an effect since, but the preliminary work on a plug-in to achieve this effect is here: http://forum.audacityteam.org/viewtopic ... 39&t=14620
There are limitations to what can be done with Nyquist plug-ins, but if the limitations are acceptable then it would probably not be too difficult to complete what was started there.

[Gale Andrews]

Someone asked about a similar (the same?) thing about 3 1/2 years ago.

So that and this should have been picked up as a feature request vote.

I was sitting on two votes for this so there are now four votes recorded on the Wiki.


Gale

[steve]

So that and this should have been picked up as a feature request vote.

Unless that user completed his plug-in and is happy with it, or was happy to use the Nyquist scripts in the Nyquist Prompt effect, or lost interest in the feature, or completed the initial task and had no further need for the effect.


From the wiki:

Envelope follower: (4 votes) Dynamically modulate the volume of one track to match the volume of another. Select a waveform, extract its volume changes over time then apply these to another waveform making its envelope behave in exactly the same way.

Could this be implemented as an option in the Auto Duck effect?

[Gale Andrews]

So that and this should have been picked up as a feature request vote.

Unless that user completed his plug-in and is happy with it, or was happy to use the Nyquist scripts in the Nyquist Prompt effect, or lost interest in the feature, or completed the initial task and had no further need for the effect.

True, but the length of that other topic looked like a serious expression of interest. I think we can say OP would have used the feature if it was there, which is just about enough for me to count a vote.

The better thing to have done would be to ask the user at the time, really.

From the wiki:

Envelope follower: (4 votes) Dynamically modulate the volume of one track to match the volume of another. Select a waveform, extract its volume changes over time then apply these to another waveform making its envelope behave in exactly the same way.

Could this be implemented as an option in the Auto Duck effect?

I've wondered that myself, but come to the conclusion that even if it was feasible it would need something like a separate tab on the effect.

If we supported pasting of envelope points then could that suggest a separate "extraction" tool?


Gale

[steve]

I've wondered that myself, but come to the conclusion that even if it was feasible it would need something like a separate tab on the effect.

It could be a "Duck or Follow" effect.

• Duck amount: Lowers the level in the selected track as the control track level increases.
• Follow amount: Lowers the level in the selected track as the control track level decreases. (it "follows" the level of the control track.)
• "Outer fade down length:" becomes "First Outer fade length:" (it fades down for ducking and fades up for following)
• "Inner fade down length:" becomes "First Inner fade length:"
• "Outer fade down length:" becomes "Second Outer fade length:" (it fades down for ducking and fades up for following)
• "Inner fade down length:" becomes "Second Inner fade length:"

In the graph, lowering the outer sections and the middle section at 0 dB would produce an "envelope follower" effect. The outer two sections would move together.

It would not precisely follow the envelope, but would be an effective envelope follower type of effect.

If we supported pasting of envelope points then could that suggest a separate "extraction" tool?

That would be a nice solution.
It would also be nice if logical operations could be performed on envelopes, such as inverting or scaling an envelope.