Automated fade-in and fade-out when recording?

[mblais]

I'd like to implement a variable fade-in period at the beginning of Record operations
(overdub, multiply, etc), and a fade-out when ending them. Ending a Record/Multiply
would switch to Overdub mode to record the fade-out period.

I'm guessing someone has probably already done this? If so, please point the way...

TIA :)

P.S. When changing controls like Input Level and Output Level, do we get a zipper
effect from the quantized steps, or is there some slew rate limiting going on under
the hood to minimize that? (if not, it would be a nice addition)

Peace,
RashaMatt

[Per Boysen]

Hesitated to answer this one since I didn't have the correct answers, but here's a hip shot anyway...

Use a script for fade in. Then use another script to (1) call the fade in script and (2) induce Record, Multiply or Overdub mode as you wich.

Why are you asking here about zipper effect? Wouldn't it be a million times quicker to simply change level and listen? :-)) I've heard a lot of zipper effects together with MIDI CC# control of continuous parameter but never in Mobius - just in the software driving different audio interfaces when using MIDI ports combined in the same hardware. Not saying that's a bad solution, today I do indeed use all MIDI ports of a RME ff400 with no problem. The computer OS can also induce zipper noise if the system is badly set up or not fast enough for the DSP.

However, zipper noise in Mobius happens when using the Pitch Shift algorithm.

[mblais]

Is there a description somewhere of how one script calls another - syntax, parameters, return values, etc?

The problem with the empirical approach to trying to answer the question, "is there a
zipper effect" is that with a simple, quick test my ears may tell me "no"; but then at a
much later date under different circumstances, I may realize that the correct answer is
actually "yes", and I wish I had known it much earlier! I prefer a definitive answer,
when it's possible to come by one.

[Jeff]

You would use scripts to get a gradual fade in/out. There some examples
of this over in the Yahoo group files section but they're mostly old and
don't use some of the newer script features like "repeat" and "while" Here's the simplest fade out.


!name Fade Out
while output > 0
set output output - 1
Wait msec 100
next


The combination of the decrement amount (1 in this case) and the delay between decrements (1/10 second in this case) determine how fast the fade will be.

There should be no zipper noise. A smoothing algorithm is applied to any change to the continuous control parameters (input, output, feedback, pan).

Pitch Shift like Per mentions is a little different. There are some bugs
in the algorithm that can cause pitch changes to have a little "bump" between them.