From 47bbfdbf1e2a6193157397938e76b16a1f60e789 Mon Sep 17 00:00:00 2001
From: Vasile Vilvoiu
−s, −−scale=SCALE
-Spectrogram scale. Valid values -are: dBFS.
+Spectrogram scale, specified +with the following format: +unit[,lower[,upper]]
-Default is -dBFS.
+unit is +an arbitrary string representing the unit of measurement +(e.g. V). lower is an optional numeric value +representing the lower bound of the scale. upper is +an optional numeric value representing the upper bound of +the scale.
-[dBFS] -NOTE: By default, the scale has a -120dB lower bound. -You can adjust it by appending the custom lower bound after -the scale string (e.g. −s dBFS-60 for a -60dB -lower bound).
+Valid values +for SCALE specify either just the unit, the unit and +the lower bound, or all three values.
+ +After
+normalization and prescaling (see −p,
+−−prescale), the following transformations
+are applied to the input:
+• if unit starts with "dB", then a
+logarithmic decibel scale is assumed: Y=20*log10(X)
+• the values are clamped between lower and
+upper: Y=clamp(X, lower, upper)
Default is +dBFS,-120,0.
[dBFS] NOTE: The peak amplitude assumed for dBFS, after -- cgit v1.2.3