30 Nov
2007
30 Nov
'07
12:11 a.m.
On Friday 30 November 2007, Dave Robillard wrote:
[...]
The current version of LV2 MIDI just uses double. All
the precision
you could ask for, or an insane range if you'd prefer. It's a bit
big maybe, but hey, why not?
We could use float I guess to save a bit of space, but I definitely
prefer floating point. Fixed point is just a PITA, modern CPUs are
much faster at FP anyway, why bother?
Well, normally, you'd use the integer part for splitting the "sample
loop" internally (that is, you need to calculate loop counts from
it), and you'd use the fractional part alone to determine offset
within the sample frame. Might be hard to avoid the weak spot of
modern CPUs that is FP<->integer conversions.
I don't know if this is a real performance issue, though. Besides, you
probably have to do some integer->FP conversions to make use of the
fractional part of integer timestamps in FP DSP code - but then
again, that impacts only the plugins that actually use it. Others
just shift the fraction bits out and use the resulting integer sample
frame offset.
//David Olofson - Programmer, Composer, Open Source Advocate
.------- http://olofson.net - Games, SDL examples -------.
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