Caption layer of dynamic spectrograms

ds_captions() adds text to a dynaspec() object at a fixed position of the figure, shown (fading in and out) during a time range of the sound, like subtitles. They are shown in the same way in all styles, in web pages and videos. To label parts of the spectrogram use the 'labels' argument of ds_annotations() instead.

Usage

ds_captions(
  labels,
  start,
  end,
  x = 0.5,
  y = 0.9,
  fading = 0,
  col = "black",
  cex = 1,
  font = 1
)

Arguments

labels

Character vector with the captions.

start, end

Numeric vectors with the start and end times (in s) of each caption.

x, y

Position of the center of the captions as proportions of the figure width and height (0-1, from the left and bottom). Defaults are 0.5 and 0.9.

fading

Duration (in s) of the fade-in and fade-out of captions. Default is 0.

col, cex, font

Color, size and font (1 = plain, 2 = bold, 3 = italic, 4 = bold italic) of the captions. Defaults are "black", 1 and 1.

Value

A layer to be added to a dynaspec() object with +. Several caption layers can be added (e.g. at different positions).

Details

Each caption layer shows one caption at a time; when the time ranges of its captions overlap the most visible one is shown.

See also

dynaspec(), ds_annotations()

Examples

data(scythebill)

x <- dynaspec(scythebill, flim = c(1.5, 5.5)) +
  ds_spectrogram(wl = 200, collevels = seq(-50, 0, 1)) +
  ds_captions(c("long note", "arched notes", "trill"), start = c(0.34, 1.13, 1.75),
              end = c(1.03, 1.68, 2.28), fading = 0.2)