find_clipping gets the proportion of samples that are clipped.
Arguments
- X
'selection_table', 'extended_selection_table' or data frame with the following columns: 1) "sound.files": name of the sound files, 2) "selec": number of the selections, 3) "start": start time of selections, 4) "end": end time of selections.
- path
Character string containing the directory path where the sound files are located. If
NULL(default) then the current working directory is used.- parallel
Numeric. Controls whether parallel computing is applied. It specifies the number of cores to be used. Default is 1 (i.e. no parallel computing).
- pb
Logical argument to control progress bar and messages. Default is
TRUE.
Value
A data frame with the 'sound.files' and 'selec' columns in X plus an additional column ('prop.clipped') indicating the proportion of clipped samples for each row. If sound files are stereo the average proportion of the two channels is returned.
Details
Clipping (i.e. saturation) occurs when an audio signal is amplified above the maximum limit of the recorder. This leads to distortion and a lowering of audio quality. If stereo the mean proportion of both channels is returned. The function assumes specific range values for different bit depths as detailed in normalize.
References
Araya-Salas, M., & Smith-Vidaurre, G. (2017). warbleR: An R package to streamline analysis of animal acoustic signals. Methods in Ecology and Evolution, 8(2), 184-191.
Author
Marcelo Araya-Salas (marcelo.araya@ucr.ac.cr)
Examples
{
# load data
data(list = c("Phae.long1", "Phae.long2", "lbh_selec_table"))
writeWave(Phae.long1, file.path(tempdir(), "Phae.long1.wav")) # save sound files
writeWave(Phae.long2, file.path(tempdir(), "Phae.long2.wav"))
find_clipping(X = lbh_selec_table[1:5, ], path = tempdir())
}
#> sound.files selec prop.clipped
#> 1 Phae.long1.wav 1 0.0000000000
#> 2 Phae.long1.wav 2 0.0005451077
#> 3 Phae.long1.wav 3 0.0000000000
#> 4 Phae.long2.wav 1 0.0000000000
#> 5 Phae.long2.wav 2 0.0000000000