Here is a stereo expansion of SilenceLength.ny
My anyone have a look or try it , whether there are any bugs?
;nyquist plug-in
;version 1
;type process
;categories "http://lv2plug.in/ns/lv2core#AnalyserPlugin"
;name "Silence Lengthen 2"
;action "Inserting silence..."
;info "Based on Silence Finder by Alex S. BrownnReleased under terms of the GNU General Public License version 2nHacked by Steve Daulton as a 'proof of concept'.nn"
;control sil-lev "Treat audio below this level as silence [ -dB]" real "" 26 0 100
;control sil-dur "Minimum duration of silence [seconds]" real "" 1.0 0.1 5.0
;control slen "Length of Silence to Insert" real "[seconds]" 1 0.1 30
(setq labelbeforedur (/ sil-dur 2.0))
;Create a function to make the sum the two channels if they are stereo
(defun mono-s (s-in) (if (arrayp s-in) (snd-add (aref s-in 0) (aref s-in 1))
s-in))
;Create a function to reduce the sample rate and prepare the signal for
;analysis. RMS is good to monitor volume the way humans hear it, but is not
;available in Audacity. Used a peak-calculating function instead.
;NOTE: this is the place to add any processing to improve the quality of the
;signal. Noise filters could improve the quality of matches for noisy signals.
;PERFORMANCE vs. ACCURACY
;Reducing the samples per second should improve the performance and decrease
;the accuracy of the labels. Increasing the samples per second will do the
;opposite. The more samples checked, the longer it takes. The more samples
;checked, the more precisely the program can place the silence labels.
;my-srate-ratio determines the number of samples in my-s. Set the number after (snd-srate s)
;higher to increase the number of samples.
(defun my-s (s-in)
(setq my-srate-ratio (truncate (/ (snd-srate (mono-s s-in)) 100)))
(snd-avg (mono-s s-in) my-srate-ratio my-srate-ratio OP-PEAK)
)
(defun space (s-in time)
(stretch-abs 1.0
(sim
(at 0 (s-rest time))
(at time (seq (cue s-in)(cue (s-rest time)))))))
;Set the silence threshold level (convert it to a linear form)
(setq thres (db-to-linear (* -1 sil-lev)))
;Store the sample rate of the sound
(setq s1-srate (snd-srate (my-s s)))
;Initialize the variable that will hold the length of the sound.
;Do not calculate it now with snd-length, because it would waste memory.
;We will calculate it later.
(setq s1-length 0)
;Initialize the silence counter and the labels variable
(setq sil-c 0)
(setq l NIL)
;Convert the silence duration in seconds to a length in samples
(setq sil-length (* sil-dur s1-srate))
;Define a function to add new items to the list of labels
(defun add-label (l-time l-text)
(setq l (cons (list l-time l-text) l))
)
;The main working part of the program, it counts
;the number of sequential samples with volume under
;the threshold. It adds to a list of markers ever time
;there is a longer period of silence than the silence
;duration amount.
;It runs through a loop, adding to the list of markers (l)
;each time it finds silence.
(let (s1) ;Define s1 as a local variable to allow efficient memory use
; Get the sample into s1, then free s to save memory
(setq s1 (my-s s))
;Capture the result of this "do" loop, because we need the sountd's legnth
;in samples.
(setq s1-length
;Keep repeating, incrementing the counter and getting another sample
;each time through the loop.
(do ((n 1 (+ n 1)) (v (snd-fetch s1) (setq v (snd-fetch s1))))
;Exit when we run out of samples (v is nil) and return the number of
;samples processed (n)
((not v) n)
;Start the execution part of the do loop
;if found silence, increment the silence counter
(if (< v thres) (setq sil-c (+ sil-c 1)))
;If this sample is NOT silent and the previous samples were silent
;then mark the passage.
(if (and (> v thres) (> sil-c sil-length))
;Mark the user-set number of seconds BEFORE this point to avoid clipping the start
;of the material.
(add-label (- (/ n s1-srate) labelbeforedur) "S")
)
;If this sample is NOT silent, then reset the silence counter
(if (> v thres)
(setq sil-c 0)
)
)
)
)
;Check for a long period of silence at the end
;of the sample. If so, then mark it.
(if (> sil-c sil-length)
;If found, add a label
;Label time is the time the silence began plus the silence duration target
;amount. We calculate the time the silence began as the end-time minus the
;final value of the silence counter
(add-label (+ (/ (- s1-length sil-c) s1-srate) sil-dur) "S")
)
;If no silence markers were found, return a message
(if (null l)
(setq l "No silences found. Try reducing the silencenlevel and minimum silence duration")
)
(setf insert (list (get-duration 1)))
(dotimes (times (length L))
(setf insert (push (car (nth times L)) insert)))
(setq insert (push 0.0 insert))
(setq slist (list (multichan-expand #'extract-abs (nth 0 insert)(nth 1 insert) s)(multichan-expand #'extract-abs (nth 1 insert)(nth 2 insert) s)))
(setf slist ())
(setq seg (1- (length insert))) ; number of segments
(dotimes (var seg)
(setf slist (push (multichan-expand #'extract-abs (nth (- seg (1+ var)) insert)(nth (- seg var) insert) s) slist)))
(seqrep (var seg)
(seq
;(cue (nth var slist))
;(cue (stretch-abs 1.0 (s-rest slen)))
(multichan-expand #'space (cue (nth var slist)) slen)
))