Paul Licameli's Spectral Editing Patch.

This relies on three new nyquist scripts to actually do the editing.  The peak-snapping code in FrequencyWindow has been extracted into a new class, SpectrumAnalyst, to provide peak-snapping in spectrogram too.

plug-ins/SpectralEditParametricEQ.ny

@@ -0,0 +1,32 @@
+;nyquist plug-in
+;version 3
+;type process
+;name "Spectral edit parametric EQ"
+;action "Calculating..."
+
+;control control-gain "Gain (dB)" real "" 0 -24 24
+
+
+(defun wet (sig gain)
+  (cond
+   ((not (or *f0* *f1*)) (throw 'debug-message "Please select frequencies"))
+   ((not *f0*) (throw 'debug-message "Bottom frequency is undefined"))
+   ((not *f1*) (throw 'debug-message "Top frequency is undefined"))
+   (t (let*
+          ((fc (sqrt (* *f0* *f1*)))
+           (width-octaves (/ (s-log (/ *f1* *f0*)) (s-log 2.0))))
+        (eq-band sig fc gain (/ width-octaves 2))))))
+
+(defun result (sig)
+  (let*
+      ((tn (truncate len))
+       (rate (snd-srate sig))
+       (transition (truncate (* 0.01 rate)))
+       (t1 (min transition (/ tn 2)))
+       (t2 (max (- tn transition) (/ tn 2)))
+       (breakpoints (list t1 1.0 t2 1.0 tn))
+       (env (snd-pwl 0.0 rate breakpoints)))
+    (sum (prod env (wet sig control-gain)) (prod (diff 1.0 env) sig))))
+
+(catch 'debug-message
+  (multichan-expand #'result s))