Rick Wright wrote:
david wrote:
Folderol wrote:
On Thu, 22 Feb 2007 13:48:04 -0600
millward <millward@xxxxxxxxxxxxxxx> 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.
Hmmm, wouldn't there actually be TWO channels for audio - stereo?
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.
That's right. But the more information you start with, the smarter the
reduction can be - particularly in areas where the 48-bit color value is
outside the 24-bit dynamic range. In photography, this means the
highlight and shadow areas. In the audio world, would mean this more
accurate renditions in the lowest and highest volume sounds? I don't know.
Depth reduction in color photography doesn't have to be a mindless
simple mathematical calculation, good software like Photoshop
(Windows/Mac) Bibble (Windows/Linux), Raw Therapee (Windows/Linux),
DCRaw (Linux) can do things more intelligently because they have more
information available to them when working with 48-bit color.
I think you can go even higher than 48-bit color in the professional
color world - I think high-end drum scanners scan at 64-bit color.
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...)
Yes, experts? I'm no audio engineer!
--
David
gnome@xxxxxxxxxxxxx
authenticity, honesty, community
