Re: [linux-audio-user] Linux music editor, greater than 32-bit ?

From: Rick Wright <riwright@email-addr-hidden>
Date: Thu Feb 22 2007 - 22:53:26 EET

david wrote:

> Folderol wrote:
>
>> On Thu, 22 Feb 2007 13:48:04 -0600
>> millward <millward@email-addr-hidden> wrote:
>>
>>> I've got a sound card capable of 96 bits, ( M-Audio audiofile 24/96 )
>>> but my sound editor, Audacity for Linux, only goes up to 32 bits.
>>> Is there a sound editor for Linux that can do higher than 32 bits?
>>
>>
>> Maybe I'm missing something here, but what on earth does anyone need
>> such high resolution for?
>>
>> ISTR The humble CD is recorded at 18bit. which is over 200,000:1 and
>> more than 100dB. The orchestral dynamic range is I believe quoted at
>> 90dB. I accept some extra headroom is nice, and the calculations aren't
>> quite so simple, but even 32bit comes out at mind boggling 200dB.
>
>
> I don't know about such things in the audio world, but in the world of
> color photography, most professional digital equipment uses 48-bit color

Yes, but this 48bit representation of color is just 16bit x3 colors
[channels]. In other words the 48bit representation is 3 unrelated
16bit [channel] representations concatenated, one each for the 3 primary
colors/CCD sensors. The equivilent for audio would be just 16bit as
there is only one channel.

> This is way outside the reproduction range of any photo
> printing/display technology. But even though a particular 48-bit color
> might not be printable or displayable, it is still there. It can be
> taken into consideration when doing color adjustments and image
> filters. The end result is that when color depth is reduced to the
> 24-bit color range that JPG uses - you get better and more accurate
> color reductions.
>
Following from above, your final JPG color depth gets reduced to just
8bits per color which is why RGB uses values from 0-255. 8bits only has
informaiton for 256 values.

> So I would think that working in higher bit-depths for audio would
> similarly result in better sounding audio when it's reduced to CD format.

This is true, but as Folderol wrote, 32 bits should be *plenty* of
dynamic range for audio. In fact, it has been argued that ~22bits is
sufficient as beyond this you get into the h/w noise floor, hearing
limits, etc.

(Any other experts out there, feel free to jump in if I'm wrong here...)

HTH,
Rick
Received on Fri Feb 23 00:15:06 2007

This archive was generated by hypermail 2.1.8 : Fri Feb 23 2007 - 00:15:06 EET