Subject: Re: [linux-audio-dev] Simple Plugin API: In/Out Ports
From: Paul Winkler (slinkp23_AT_yahoo.com)
Date: ma maalis 06 2000 - 18:22:27 EST
Bill Gribble wrote:
>
> > And even 16 bit integer signal paths with 32 bit integer processing
> > is good enough for non-pro signal processing, such as multimedia
> > systems, games, arcade game machines and the like.
>
> I think this integer = non-pro, float = pro dichotomy is bogus.
Yes, but...
> a lot of reasons why integer representations are better. For a given
> number of bits in your value, a floating-point representation wastes
> much of your available information in large and small values that are
> far, far beyond the limits of your ultimate destination and will never
> be used in real applications.
...but that's very good insurance. It's not hard to come up with a
chain of processors that radically changes the overall signal level.
It seems very convenient to me to be able to do one large gain
correction after all your processing and still know that you kept 24
(or is it 23?) bits of significant information all the way through.
Correct me if I'm wrong, but it seems to me that floats enable the
engineer to pretty much stop worrying about gain structure except
when dealing with plugins with deliberately non-linear response. A
32-bit int, while having quite a lot of headroom, is probably not as
forgiving unless the programmers have paid a lot more attention...
right? wrong?
And I think this has been mentioned before, but we should DEFINITELY
try to keep it simple to compile 64-bit versions of hosts and
plugins. I don't know if this takes more than a typedef, but it
needs to be considered now. During discussions of double vs.
single-precision floats on the csound mailing list, several more
knowledgeable persons than I asserted that even on
current-generation intel hardware, double-precision arithmetic isn't
really slower than single-precision, and that for some filter
algorithms it really does make a significant difference in the
quality of the result. We'll all be moving to 64 bit systems at some
time (by 2005? 2010?), so we should be ready. And people with the
RAM to burn should have the option to compile their system for
doubles *now*.
--Paul
................ paul winkler ..................
slinkP arts: music, sound, illustration, design, etc.
A member of ARMS -----> http://www.reacharms.com
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personal page ----> http://www.ulster.net/~abigoo
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