Code from class, 2012-11-05

class-code-2012-11-05.rkt

(require (planet clements/rsound:4:3))
(require (planet clements/rsound:4:3/filter))

(define SONG (rs-read "/tmp/bette-davis-eyes.wav"))

(define (looper sound)
  (local [(define len (rs-frames sound))]
  (network ()
           [ctr ((loop-ctr len 1))]
           [out (/ (+ (rs-ith/left sound ctr)
                      (rs-ith/right sound ctr))
                   2)])))

#|Recurrence relation:
y[n] = (  1 * x[n- 4])
     + (  4 * x[n- 3])
     + (  6 * x[n- 2])
     + (  4 * x[n- 1])
     + (  1 * x[n- 0])

     + ( -0.9217826364 * y[n- 4])
     + (  3.7553687929 * y[n- 3])
     + ( -5.7449584093 * y[n- 2])
     + (  3.9113581121 * y[n- 1])

gain at dc    :   mag = 1.131484017e+06   phase =   0.0000000000 pi

|#
(signal-play
 (network ()
          [sound ((looper SONG))]
          ;[t1 ((tap 1 0.0) sound)]
          ;[t2 ((tap 2 0.0) sound)]
          ;[t3 ((tap 3 0.0) sound)]
          ;[t4 ((tap 4 0.0) sound)]
          ;[b1 (prev out 0.0)]
          ;[b2 ((tap 1 0.0) (prev out 0.0))]
          ;[b3 ((tap 2 0.0) (prev out 0.0))]
          ;[b4 ((tap 3 0.0) (prev out 0.0))]
          ;[out (+ sound 
          ;        (* 4 t1)
          ;        (* 6 t2)
          ;        (* 4 t3) 
          ;        t4
          ;        (* 3.9113581121 b1)
          ;        (* -5.7449584093 b2)
          ;        (* 3.7553687929 b3)
          ;        (* -0.9217826364 b4))]
          
          ;[quieter (* 0.000001 out)]
          #;[fc (sine-wave 0.3)]
          [out (lpf/dynamic 0.4 sound)]
          [out2 (- sound out)]
          ))