osc: Oscillogram

View source: R/osc.R

oscR Documentation

Oscillogram

Description

Plots the oscillogram (waveform) of a sound on a linear or logarithmic scale (in dB). To get a dB scale, centers and normalizes the sound, then takes a logarithm of the positive part and a flipped negative part, which is analogous to "Waveform (dB)" view in Audacity. For more plotting options, check oscillo.

Usage

osc(
  x,
  samplingRate = NULL,
  scale = NULL,
  from = NULL,
  to = NULL,
  dynamicRange = 80,
  dB = FALSE,
  returnWave = FALSE,
  reportEvery = NULL,
  cores = 1,
  plot = TRUE,
  savePlots = NULL,
  main = NULL,
  xlab = NULL,
  ylab = NULL,
  ylim = NULL,
  bty = "n",
  midline = TRUE,
  maxPoints = 10000,
  width = 900,
  height = 500,
  units = "px",
  res = NA,
  ...
)

Arguments

x

path to a folder, one or more wav or mp3 files c('file1.wav', 'file2.mp3'), Wave object, numeric vector, or a list of Wave objects or numeric vectors

samplingRate

sampling rate of x (only needed if x is a numeric vector)

scale

maximum possible amplitude of input used for normalization of input vector (only needed if x is a numeric vector)

from, to

if NULL (default), analyzes the whole sound, otherwise from...to (s)

dynamicRange

dynamic range, dB. All values more than one dynamicRange under maximum are treated as zero

dB

if TRUE, plots on a dB instead of linear scale

returnWave

if TRUE, returns a log-transformed waveform as a numeric vector

reportEvery

when processing multiple inputs, report estimated time left every ... iterations (NULL = default, NA = don't report)

cores

number of cores for parallel processing

plot

if TRUE, plots the oscillogram

savePlots

full path to the folder in which to save the plots (NULL = don't save, ” = same folder as audio)

main

plot title

xlab, ylab

axis labels

ylim

override default amplitude scale for non-centered sounds

bty

box type (see '?par')

midline

if TRUE, draws a line at 0 dB

maxPoints

the maximum number of points to plot (speeds up the plotting of long audio files, but beware of antialiasing)

width, height, units, res

graphical parameters for saving plots passed to png

...

Other graphical parameters passed on to 'plot()'

Value

If returnWave = TRUE, returns the input waveform on the original or dB scale: a vector with range from '-dynamicRange' to 'dynamicRange'.

Examples

sound = sin(1:2000/10) *
        getSmoothContour(anchors = c(1, .01, .5), len = 2000)

# Oscillogram on a linear scale without bells and whistles, just base R
plot(sound, type = 'l')

# Oscillogram options with soundgen
osc(sound)             # linear
osc(sound, dB = TRUE)  # dB

# For numeric vectors, indicate samplingRate and scale (max amplitude)
osc(sound, samplingRate = 1000, scale = 100, dB = TRUE)

# Embellish and customize the plot
o = osc(sound, samplingRate = 1000, dB = TRUE, midline = FALSE,
        main = 'My waveform', col = 'blue', returnWave = TRUE)
abline(h = -80, col = 'orange', lty = 3)
o[1:10]  # the waveform in dB

## Not run: 
# Wave object
data(sheep, package = 'seewave')
osc(sheep, dB = TRUE)

# for long files, reduce the resolution to plot quickly (careful: if the
# resolution is too low, antialiasing may cause artifacts)
osc(sheep, dB = TRUE, maxPoints = 2500)
osc(sound, samplingRate = 5000, maxPoints = 100)

# files several minutes long can be plotted in under a second
osc('~/Downloads/speechEx.wav', maxPoints = 20000)

# saves oscillograms of all audio files in a folder
osc('~/Downloads/temp2', savePlots = '')

## End(Not run)

soundgen documentation built on Aug. 14, 2022, 5:05 p.m.