naturerecordists
[Top] [All Lists]

Re: EIN values and bits

Subject: Re: EIN values and bits
From: "Raimund" animalsounds
Date: Fri Dec 7, 2012 7:04 am ((PST))
> But if that conversion were to floating point rather than fixed
> point data, and then converted to fixed point after the attenuator,
> that would seem to be a valid way to get the signal in the right
> gain range for storage in a file.

I think a simple digital attenuator would not require floating point arithmetic 
at all because there is only a single multiplication involved. Things may 
become a bit more complicated if an additional 24 to 16 bit conversion with 
dithering was required, but I guess that this could still be done properly with 
fixed point arithmetic. 

I also believe that most (if not all) digital field recorders currently use 
low-power fixed-point DSPs rather than more complex and more power-hungry 
floating-point models.

Post processing in sound editing software however would be a different story 
because such a system must be prepared to properly handle numerous subsequent 
processing steps where rounding errors could be an issue. 

Interestingly, even the 32 bit floating point format can potentially cause 
trouble in algorithms that require accumulating many small numbers into a much 
larger sum.

Regards,
Raimund








<Prev in Thread] Current Thread [Next in Thread>
Admin

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the naturerecordists mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU