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Subject: Re: logarithmic volume control
From: Bjoern Fischer (bfischer_at_Techfak.Uni-Bielefeld.DE)
Date: 2002-08-07


> Hello Bjoern,

> BF> Has anyone thought about a volume control with a logarithmic or sqrt
> BF> characteristic? The volume control steps are very small within 0%-60%
> BF> and quite large, when approaching max volume. A perfect solution would
> BF> be a configurable characteristic: linear, log, sqrt, square.

> You could implement this function as a 2-dimensional array with
> precalculated values (rockbox has no floating point unit). Then it's
> easy to change the scale. I think it won't be more than 20 values per
> scale.

Exactly. The code is already there, now I just have to set up the compiling
environment (native FreeBSD). The DSP seems to have a 6 Bit value for
volume, i.e. volume can be set to 64 different values. If we provide
3 or 4 different characteristics, that every user will get his preferred
volume range with a high resolution, then 20 steps should be sufficient.

If I get that compiler stuff running, I'll post some code tonight.

Do we already have a stable API for persistent configuration parameters?

Björn



Page was last modified "Jan 10 2012" The Rockbox Crew
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