Re: [Audacity-quality] Truncate Silence

[Gale A. <ga...@au...>]

| From Steve the Fiddle <ste...@gm...> 
| Fri, 15 Nov 2013 17:46:20 +0000
| Subject: [Audacity-quality] Truncate Silence
> On 15 November 2013 13:18, Steve the Fiddle <ste...@gm...> wrote:
> > I've been looking closely at the Truncate Silence effect with a view
> > to fixing bug 433.
> >
> > This effect is unbelievably complicated. I doubt that anyone can,
> > without looking at the code or making in-depth tests, describe
> > precisely what it does. Even the manual is not completely accurate and
> > a lot of effort went into that.

Could you fix the Manual or add a P rating according to the severity 
of the problem?  


> > The word "truncate" usually means "cutting the end off", but here it
> > is used in the more general sense of "to make shorter".
> >
> > The detection of "silence" is simple. The effect just looks for audio
> > that is below the threshold level.
> >
> > The effect then calculates how much audio to remove (this is the
> > complicated bit) and then deletes that amount from the middle of the
> > "silence"
> >
> > The calculation:
> >
> > DeleteAmount =
> > if ((MinDuration + ((InitialDuration - MinDuration) / Ratio)) < MaxDuration)
> > then (InitialDuration - (MinDuration + ((InitialDuration -
> > MinDuration) / Ratio)))
> > else (InitialDuration - MaxDuration)
> 
> Sorry, even that was not quite right.
> I think this  is right, but even more complicated:
> 
> If (InitialDuration > MinDuration)
> then
> (if ((MinDuration + ((InitialDuration - MinDuration) / Ratio)) < MaxDuration)
> (InitialDuration - (MinDuration + ((InitialDuration - MinDuration) / Ratio)))
> else (InitialDuration - MaxDuration))
> else
> do nothing.
> 
> Steve
> 
> > "DeleteAmount" is then deleted from the middle of the silence.

Is that "DeleteAmount" operation acting on the middle of the silence 
OK, or do you think it should truncate starting from the end? 

Are there different use cases for it to do one or the other?  



Gale 


> >
> > I'm finding it very tough to make the interface clear because what it
> > is doing is so complicated. Does this effect really need to be so
> > complicated or am I at liberty to simplify the algorithm?
> >
> > Steve