alpass.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

(ALPASS-ALG
(NAME "alpass")
(ARGUMENTS ("sound_type" "input") ("time_type" "delay") ("double" "feedback"))
(START (MIN input))
(STATE ("double" "feedback" "feedback")
       ("long" "delaylen" "MAX(1, round(input->sr * delay))")
       ("sample_type *" "delaybuf"
               "(sample_type *) calloc (susp->delaylen, sizeof(sample_type))")
       ("sample_type *" "delayptr" "susp->delaybuf")
       ("sample_type *" "endptr" "susp->delaybuf + susp->delaylen"))
(CONSTANT "feedback" "delaylen" "endptr")
(NOT-REGISTER delaybuf)
(LINEAR input)
(TERMINATE (MIN input))
(INNER-LOOP-LOCALS "register sample_type y, z;\n")
(INNER-LOOP "	    y = *delayptr;
        *delayptr++ = z = (sample_type) (feedback * y + input);
        output = (sample_type) (y - feedback * z);
        if (delayptr >= endptr) delayptr = susp->delaybuf;")
(FINALIZATION "free(susp->delaybuf);")
)