linuxaudio.org

On Friday, November 12, 2010 11:43:42 am Eric Kampman did opine:
> On Nov 12, 2010, at 1:40 AM, Jens M Andreasen wrote:

quoted text
> > On Thu, 2010-11-11 at 20:22 -0800, Eric Kampman wrote:

> >> Since power is proportional to signal squared, this means ..

> >> .. L(t) = cos(t * pi / 2) and R(t) = cos((1 - t) * pi / 2)

> >

> > I think you misspelled one sin(), no?

>

> No, turns out the 2nd equation is equivalent to sin(t * pi / 2) I think.

And is computationally less expensive if you drop the pi / 2 and use

pi * 0.5 as mulls cost less than divs.  Or at least this is true if its not

handed off to an FP processor. ;-)
> > It is a complex mul you really want - where L+R is the real and L-R is

quoted text
> > the imaginary. You can have the sin/cos pair very cheaply by using an

> > LFO that works by rotating iself by some complex constant.

>

> Great idea. Will use. Thanks.

--

Cheers, Gene

"There are four boxes to be used in defense of liberty:

 soap, ballot, jury, and ammo. Please use in that order."

-Ed Howdershelt (Author)

Don't get suckered in by the comments -- they can be terribly misleading.

Debug only code.

		-- Dave Storer

_______________________________________________

Linux-audio-dev mailing list

Linux-audio-dev@lists.linuxaudio.org

http://lists.linuxaudio.org/listinfo/linux-audio-dev