soundgen (version 2.3.0)

fade: Fade

Description

Applies fade-in and/or fade-out of variable length, shape, and steepness. The resulting effect softens the attack and release of a waveform.

Usage

fade(
  x,
  fadeIn = 1000,
  fadeOut = 1000,
  samplingRate = NULL,
  shape = c("lin", "exp", "log", "cos", "logistic", "gaussian")[1],
  steepness = 1,
  plot = FALSE
)

Arguments

x

zero-centered (!) numeric vector such as a waveform

fadeIn, fadeOut

length of segments for fading in and out, interpreted as points if samplingRate = NULL and as ms otherwise (0 = no fade)

samplingRate

sampling rate of the input vector, Hz

shape

controls the type of fade function: 'lin' = linear, 'exp' = exponential, 'log' = logarithmic, 'cos' = cosine, 'logistic' = logistic S-curve

steepness

scaling factor regulating the steepness of fading curves (except for shapes 'lin' and 'cos'): 0 = linear, >1 = steeper than default

plot

if TRUE, produces an oscillogram of the waveform after fading

Value

Returns a numeric vector of the same length as input

See Also

crossFade

Examples

# NOT RUN {
#' # Fading a real sound: say we want fast attack and slow release
s = soundgen(attack = 0, windowLength = 10,
             sylLen = 500, addSilence = 0)
# playme(s)
s1 = fade(s, fadeIn = 40, fadeOut = 350,
          samplingRate = 16000, shape = 'cos', plot = TRUE)
# playme(s1)

# Illustration of fade shapes
x = runif(5000, min = -1, max = 1)  # make sure to zero-center input!!!
# plot(x, type = 'l')
y = fade(x, fadeIn = 1000, fadeOut = 0, plot = TRUE)
y = fade(x, fadeIn = 1000, fadeOut = 1500,
         shape = 'exp', steepness = 1, plot = TRUE)
y = fade(x, fadeIn = 1500, fadeOut = 500,
         shape = 'log', steepness = 1, plot = TRUE)
y = fade(x, fadeIn = 1500, fadeOut = 500,
         shape = 'log', steepness = 3, plot = TRUE)
y = fade(x, fadeIn = 1500, fadeOut = 1500,
         shape = 'cos', plot = TRUE)
y = fade(x, fadeIn = 1500, fadeOut = 1500,
         shape = 'logistic', steepness = 1, plot = TRUE)
y = fade(x, fadeIn = 1500, fadeOut = 1500,
         shape = 'logistic', steepness = 3, plot = TRUE)
y = fade(x, fadeIn = 1500, fadeOut = 1500,
         shape = 'gaussian', steepness = 1.5, plot = TRUE)
# }