From 47bbfdbf1e2a6193157397938e76b16a1f60e789 Mon Sep 17 00:00:00 2001 From: Vasile Vilvoiu Date: Fri, 16 Jul 2021 18:32:27 +0300 Subject: Add support for arbitrary scales, with custom units. Add support for linear scales. Logging of scale to stderr. Closes #9. --- man/specgram.1 | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) (limited to 'man/specgram.1') diff --git a/man/specgram.1 b/man/specgram.1 index 971af9d..6e60aaa 100644 --- a/man/specgram.1 +++ b/man/specgram.1 @@ -1,4 +1,4 @@ -.TH SPECGRAM 1 "2021-07-15" +.TH SPECGRAM 1 "2021-07-16" .SH NAME specgram \- create spectrograms from raw files or standard input @@ -192,13 +192,19 @@ Default is \fIRATE\fR/2. .TP .BR \-s ", " \-\-scale =\fISCALE\fR -Spectrogram scale. -Valid values are: dBFS. +Spectrogram scale, specified with the following format: \fIunit\fR[,\fIlower\fR[,\fIupper\fR]] -Default is dBFS. +\fIunit\fR is an arbitrary string representing the unit of measurement (e.g. \fBV\fR). +\fIlower\fR is an optional numeric value representing the lower bound of the scale. +\fIupper\fR is an optional numeric value representing the upper bound of the scale. -\fB[dBFS] NOTE:\fR 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. \fB\-s dBFS-60\fR for a -60dB lower bound). +Valid values for \fISCALE\fR specify either just the unit, the unit and the lower bound, or all three values. + +After normalization and prescaling (see \fB\-p, \-\-prescale\fR), the following transformations are applied to the input: + \(bu if \fIunit\fR starts with "dB", then a logarithmic decibel scale is assumed: Y=20*log10(X) + \(bu the values are clamped between \fIlower\fR and \fIupper\fR: Y=clamp(X, \fIlower\fR, \fIupper\fR) + +Default is dBFS,-120,0. \fB[dBFS] NOTE:\fR The peak amplitude assumed for dBFS, after normalization and prescaling (see \fB\-p, \-\-prescale\fR), is 1.0. Thus, the correct input domains are: @@ -360,4 +366,4 @@ Program icon by Flavia Fabian, released under the CC-BY-SA 4.0 license. Share Tech Mono font by Carrois Type Design, released under Open Font License. -Special thanks to Eugen Stoianovici for code review and various fixes. \ No newline at end of file +Special thanks to Eugen Stoianovici for code review and various fixes. -- cgit v1.2.3