Stop and instantly rewind Augustus Loop?

[pdcawley]

So, one thing I've been doing with Apple's mostly terrible Loopback looper is recording a chorus loop, stopping it, then overdubbing harmonies each time through the chorus of a song. I'm an unaccompanied folk singer, so verse timings can get pretty free (deliberately so), so I set the plugin to always play from the start.

I'd like to be able to do something similar my AL scripts, but there doesn't seem to be a way to manipulate the tape head position.

I suppose I could do something like:

Code: Select all

function stopTape() 
  setParameter(param.stop, 1.0)
  if getParameter(param.tap) > 0 then
    setParameter(param.tap, 0)
  end
end

local oneshotTimer = nil
function startOneshot(inputLevel) 
  setParameter(param.input, inputLevel)
  setParameter(param.stop, 0.0)
  now = time()
  stopTime = now + getParameter(param.delayLength)
  oneshotTimer = requestTimedCallback(stoptime - time(), stopTape)
end

But it feels like a horrible hack. Is there a better way, or should I just live with the kluge?

[os]

Since AL uses a tape paradigm, there's really no concept of 'the start' - it's just a loop. There's no way to move the head position around.

[pdcawley]

Yeah. Presumably, internally at least, there is some concept of whereabouts in the audio buffer the head is at any given point (or PositionQ makes no sense as a punch out mode). If that were exposed as a parameter, then it becomes possible to have a script keep track of its own start point, but I'm guessing that's easier said than done.

I realise I'm trying to squeeze AL through a Mobius Looper shaped hole here, but here I am in 64-bit world and Mobius is resolutely stuck in 32-bit world. AL appears to be the only scriptable game in town. (And it sounds _great_)

[os]

There is a RAM buffer of course, which has a 'current position'. I could expose prodding that, but there would be no guarantees of smooth audio transitions if you start jumping around in the buffer.

[pdcawley]

Right. For my purposes, I'd be unlikely to have a glitch issue because I'd be jumping about with input and output both set to zero. Being able to trigger a crossfaded jump after 'Inertia Fade' milliseconds would be marvellous, but entirely unnecessary for what I want to do. Who knows what someone else might want to do with the idea.

[os]

It seems to work - beta to try here:

https://github.com/expertsleepersltd/issues/issues/117

This is very low level access - use with care!

[pdcawley]

Thanks so much! I kind of ran out of programming steam over the weekend, but I’ll definitely be looking at this soon!

[pdcawley]

Hmm… initial testing suggests that a rewind isn’t the way to go: I need to jump forward to the next multiple of the loop length.

I’ll have a script to show off soon, I hope