#!r6rs
(library (rsc3 math gain)
(export ampdb dbamp)
(import (rnrs)
	(only (rsc3 math log) log10))

;; Convert a linear rms gain value to a decibel value and the inverse.
;; Zero decibels is unity gain.  These algorithms are from SC3.

(define (ampdb amp) (* (log10 amp) 20))
(define (dbamp db)  (expt 10 (* db 0.05)))

(define (powdb pow) (* (log10 pow) 10))
(define (dbpow db)  (expt 10 (* db 0.1)))

)