Re: [SoX-users] toward floating-point?

[Cory N. <ph...@gm...>]

On Mon, Mar 5, 2012 at 1:09 PM, Jan Stary <ha...@st...> wrote:
> On Mar 05 17:04:04, robs wrote:
>>
>> >Perhaps I am missing something here,
>> >but how would that make gains not clip?
>>
>>
>> Because FP can represent very large numbers, clipping in the effects chain becomes very unlikely, and a (downwards) normalisation could be applied at the end of chain to bring things back in check.
>
> I still don't get it: on my system, sizeof(float) = 4.
> How can four-byte floats represent larger dynamic range
> than four-bytes integers (which, if I remember right,
> is currently SoX's internal sample format)?
>

Float has less precision (only 24 bits, which is plenty for audio),
but a much larger dynamic range. The point is that:

0.75 * 2 = 1.5 (can be normalized back to 1.0 range)
1610612735 * 2 = 2147483647 (clipped unrecoverably by 1/3rd)

It is practically impossible to unrecoverably clip while using float.
You'd need to have some pretty heroic and nonsensical filters.

-- 
Cory Nelson
http://int64.org