Help me please with LOG function

Metallist · Jun 21, 2005, 06:07 AM

Help me please with LOG function

See example:

input in;
output out;
control volume=0x19999999, exponent=0x2ccccccc;
temp t
;code
log t, in, exponent, 0x0;
macs out, 0x0, t, volume;
end

Situation: when moving exponent slider the shape of output signal does not change smooth, but unevenly(bouncely).
Problem: WHY DOES IT HAPPEN SO ?????

I am sorry for my English if my spelling isn't right

Russ · Jun 21, 2005, 06:26 AM

For one thing the range of the Max Exponent parameter is 0x1 to 0x1F (1 to 31), while the control's range is 0x0 to 0x7FFFFFFF (fractional values), so I am unsure what would happen when you use the instruction with invalid parameters.

radiocolonel.it · Jun 21, 2005, 06:35 AM

Quote:

Originally Posted by Metallist

Help me please with LOG function

See example:

input in;
output out;
control volume=0x19999999, exponent=0x2ccccccc;
temp t
;code
log t, in, exponent, 0x0;
macs out, 0x0, t, volume;
end

Situation: when moving exponent slider the shape of output signal does not change smooth, but unevenly(bouncely).
Problem: WHY DOES IT HAPPEN SO ?????

I am sorry for my English if my spelling isn't right

the "exponent" is what usually is called "resolution", it is a number between the 1-31 and the highier it is the better is the approximation of the log function!

Metallist · Jun 21, 2005, 08:41 AM

Thanks. I solved a problem when I multiplied the value of exponent slider by 0x1F. And now when slider ranges from 0 to 2147483647, then exponent ranges from 0 to 31.

I am sorry for my English if my spelling isn't right

radiocolonel.it · Jun 21, 2005, 10:22 AM

... Are u doing something like yhis?

Quote:

input inl, inr
output outl, outr
static resolution=0x0, tmp=0x0
control amount=0
macs resolution, 0, amount, 0x1f

macints tmp, 0, inl, 0x4
log tmp, tmp, resolution, 0x0
macs outl, 0, tmp, 0.25

macints tmp, 0, inr, 0x4
log tmp, tmp, resolution, 0x0
macs outr, 0, tmp, 0.25

end

Metallist · Jun 21, 2005, 12:45 PM

Yes, you're right.
But there is one bound by 5 dB at 52% of "amount" slider.

But now it isn't very big problem for me.
But it is still interesting, why there is such bound.