tone.alg

Audacity是一款用於錄音和編輯聲音的、免費的開放源碼軟體。它可以執行於Mac OS X、Microsoft Windows、GNU/Linux和其它作業系統

(TONE-ALG
(NAME "tone")
(ARGUMENTS ("sound_type" "input") ("double" "hz"))
(START (MIN input))
(TERMINATE (MIN input))
(LOGICAL-STOP (MIN input))
(STATE ("double" "b" "2.0 - cos(hz * PI2 / input->sr)" TEMP)
       ("double" "c2" "b - sqrt((b * b) - 1.0)")
       ("double" "c1" "(1.0 - susp->c2) * input->scale")
       ("double" "prev" "0.0"))
(INTERNAL-SCALING input)
(CONSTANT "c1" "c2")
(INNER-LOOP "output = (sample_type) (prev = c1 * input + c2 * prev)")
)