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normalize

Rescale the range of values

Description

Centering and rescaling the waveform of a Wave or WaveMC object to a canonical interval corresponding to the Wave format (e.g. [-1, 1], [0, 254], [-32767, 32767], [-8388607, 8388607], or [-2147483647, 2147483647]).

Usage

normalize(object, unit = c("1", "8", "16", "24", "32", "64", "0"), 
    center = TRUE, level = 1, rescale = TRUE, pcm = object@pcm)

Arguments

object

Object of class Wave or WaveMC.
unit

Unit to rescale to.
"1" (default) for rescaling to numeric values in [-1, 1],
"8" (i.e. 8-bit) for rescaling to integers in [0, 254],
"16" (i.e. 16-bit) for rescaling to integers in [-32767, 32767],
"24" (i.e. 24-bit) for rescaling to integers in [-8388607, 8388607],
"32" (i.e. 32-bit) for rescaling either to integers in [-2147483647, 2147483647] (PCM Wave format if pcm=TRUE) or to numeric values in [-1, 1] (FLOAT_IEEE Wave format if pcm = FALSE),
"64" (i.e. 64-bit) for rescaling to real values in [-1, 1] (FLOAT_IEEE Wave format), and
"0" for not rescaling (hence only centering if center = TRUE).
center

If TRUE (default), values are centered around 0 (or 127 if unit = "8").
level

Maximal percentage of the amplitude used for normalizing (default is 1).
rescale

Logical, whether to rescale to the maximal possible dynamic range.
pcm

Logical. By default, the pcm information from the object is kept. Otherwise, if TRUE, the object is coerced to the PCM Wave format. If FALSE, the object is coerced to the FLOAT_IEEE format, i.e. numeric values in [-1, 1].

Value

An object containing the normalized data of the same class as the input object, i.e. either Wave or WaveMC.

Author(s)

Uwe Ligges ligges@statistik.tu-dortmund.de, Sarah Schnackenberg, based on code from Matthias Heymann's former package ‘sound’.

See Also

tuneR

Analysis of Music and Speech

v1.3.3
GPL-2 | GPL-3
Authors
Uwe Ligges <ligges@statistik.tu-dortmund.de> with contributions from Sebastian Krey, Olaf Mersmann, Sarah Schnackenberg, Guillaume Guenard, Andrea Preusser, Anita Thieler, Johanna Mielke and Claus Weihs, as well as code fragments and ideas from the former package 'sound' by Matthias Heymann and functions from 'rastamat' by Daniel P. W. Ellis. The included parts of the libmad MPEG audio decoder library are authored by Underbit Technologies.
Initial release
2018-07-03

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