tuneR (version 1.4.7)

lifter: Liftering of cepstra

Description

Apply liftering to a matrix of cepstra.

Usage

lifter(x, lift = 0.6, inv = FALSE, htk = FALSE)

Value

Matrix of the liftered cepstra.

Arguments

x

Matrix of cepstra, one sample/time frame per column.

lift

Liftering exponent/length.

inv

Invert the liftering (undo a previous liftering).

htk

Switch liftering type.

Author

Sebastian Krey

Details

If htk = FALSE, then perform \(x i^lift\), \(i = 1, \ldots,\) nrow(x) liftering. If htk = TRUE, then perform HTK-style sin-curve liftering with length lift.

References

Daniel P. W. Ellis: https://www.ee.columbia.edu/~dpwe/resources/matlab/rastamat/

Examples

  testsound <- normalize(sine(400) + sine(1000) + square(250), "16")
  m <- melfcc(testsound, frames_in_rows=FALSE)
  unlm <- lifter(m, inv=TRUE)