annotate examples/sound/sampled/specfilter.scm @ 8:5e3cbbf173aa tip

Reorganise some more

;;; Example of some more complicated spectral processing. 
;;; We read two audio inputs: one from the sound card and one
;;; from a file.  Then we filter one by the spectrum of the
;;; other.

(load "functions.scm")
(load "models.scm")
(load "lineout.scm")
(load "audio.scm")
(load "synthesis.scm")
(load "filelist.scm")

(define size 512)			; size of STFT frames
(define hop 128)			; hops size
(define fmt (mono 22050))
(tasks)

;; X is an object or unit which manages the FT of live input.
;; Y is an object or unit which manages the FT of the file input.
;; f is the normalised magnitude spectrum of the file input.
;; z is the magnitude spectrum of the live input
(define X (ft-vec (norm (linein (linesrc (default-mixer) fmt) size hop))))
(define Y (node "filter" (ft-vec (norm (linein (filesource) size hop)))))
(define f (diffscale (ft-mag Y) cauchy-spec))
(define z (ft-mag X))
; (define f (VVector. "filter" (.size z)))

; at this point, the task list has a lot of stuff in it: everything
; required to generate f and z when the main loop is run.

(put "lineout.scale" 1.0e-5)	; get a lot of clipping if this is too large
(.setWindow X (Constant. 1.0))	; override Hanning window in STFT default

; this adds a task to multiply z (in place) by f
(addtasks (task (Mathx.mul (.array z) (.array f)))) 

; invert FT wih new magnitudes from z
; then overlap-and-add output to audio output
(overlap-and-add (linesnk (mixer-n 2) fmt)
	(rescaled-ift Y z hop))

(expose)

; at this point the task list is ready and the whole
; is started by calling (start) or pressing the start button
; on the Regulator GUI.:w