FadeIn/Out Audio

[mg262]

Random note... I was recently helping a musician friend of mine create some clips using AviSynth and he complained that it just 'sounded wrong' during the fade part of FadeIO(2). By contrast, he was happy with the fade created by Creative WaveStudio.

Looking at the waveforms, I get the impression that AviSynth uses a linear fade, whereas WaveStudio uses a logarithmic fade (i.e. -x dB/s for some x) -- although I haven't checked against the source.

I'm not myself qualified to judge which one is right or appropriate for what tasks, so this is just an observation... hope it's of some interest.

Mohan

[IanB]

@Mohan,

You Muso mate is not wrong, AVS uses linear transitions and it does sound a bit imperfect. :sly:

Also versions prior to 2.5.6 (or was it 5, have to check the CVS) have a bug with non mono clips.

IanB

[mg262]

Right. Thanks!

[sh0dan]

Which type to use is probably a personal preference - Cooledit uses linear fadein/outs IIRC. It could however be added as an option.

There is the slight problem of defining '0', when working in decibels. -48dB is not quiet -96dB might lead to a too steep fadeout, etc.

[Mug Funky]

perhaps a "zero point" could be specified with it?

audacity uses log fades. i'm not sure how it controls them, but they come out pretty good.

[edit]

btw, cool edit's multitrack gives you the choice of linear, sine or log. everything's done using envelopes, so all that means is it spits out a bunch of spline handles over the current selection. a simple log fade would be enough for avisynth. anything too complex and you might as well do all your audio in a multitrack editor that supports video previewing (that's what i like to do).

[mg262]

Maybe measure the cutoff rate from an existing editor and use it as an overrideable default? (I'll try the measuring if it's useful.)