Re: [SoX-users] partial fade in

[Martin G. <so...@fa...>]

On 19/07/25 15:46, Nicolas Graner wrote:
> Hello all,
>
> I would like to ramp the volume of an audio file from a given level to
> full volume over a specified time interval. For instance, increase the
> level linearly from 30% at time t=0 to 100% at time t=10s. In other
> words, perform a fade in starting from a level greater than 0.
>
> I can do it by inserting an appropriate amount of silence before the
> beginning, performing a fade in, then removing the extra silence. But
> this seems unnecessarily complex, especially if the effect is to be
> applied at a time other than the beginning. Is there a better way to do
> it with SoX ?

One way would be to duplicate the track into one copy at a constant 
volume of 30% and the other with a fade-in from 0 to 70% and then mix 
them together but it seems like a bit of a contortion.

It would be better if fade could be told to start (and/or end) at a 
level higher than zero, such as

     fade --min 30 --max 100

with a little thought as to what that means when the fade shape is not 
linear.

https://codeberg.org/sox_ng/sox_ng/issues/525 should be included in 
sox_ng-14.7.0 in November 2025.


    M