[LAD] panning thoughts
fons at kokkinizita.net
fons at kokkinizita.net
Sat Nov 13 15:26:36 UTC 2010
On Sat, Nov 13, 2010 at 02:57:44PM +0000, Folderol wrote:
> Paul Davis <paul at linuxaudiosystems.com> wrote:
>
> > there's an awful lot of math for which a modern processor can compute
> > the answer faster than it can look it up. this is one such example (as
> > fons noted), but there are many others. this started changing about 8
> > years ago, and its only gotten more true since then.
>
> Oh dear. I didn't realise I was so far out of date :(
It's absolutely true.
Note that the calculation I posted earlier runs entirely on
the FP processor, and two variables, q and d, will probably
only exist there and never be written to memory. If it takes
any time at all, the CPU can meanwhile do something else,
such as getting the pointers to the audio data it will need
later. Using a LUT will mean the CPU has to do all the work,
which includes getting the base pointer and calculating the
required offset(s).
Ciao,
--
FA
There are three of them, and Alleline.
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