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Estimate spectral envelope using the True Envelope (Teager energy) method

trk_covarep_env_te.Rd

Extracts a smooth spectral envelope and compact cepstral representation per frame using cepstral liftering. The True Envelope method separates the slow-varying spectral shape from fine harmonic structure, making it useful for voice quality and vocal tract characterization independent of F0.

Usage

trk_covarep_env_te(listOfFiles, beginTime = 0, endTime = 0, frameSize = 30, frameShift = 5, cep_order = 24, toFile = FALSE, explicitExt = "ete", outputDirectory = NULL, verbose = TRUE)

Arguments

listOfFiles

Character vector of audio file paths. Any format supported by av is accepted; non-native inputs are transcoded automatically.

frameSize

Numeric. Analysis window length in milliseconds. Default 30 ms.

frameShift

Numeric. Frame shift in milliseconds; sets output frame rate (1000 / frameShift Hz). Default 5 ms.

cep_order

Integer. Cepstral order for envelope reconstruction. Controls smoothness of the recovered envelope: lower values yield smoother envelopes (safe range 12–40). Default 24.

toFile

Logical. If TRUE, write SSFF output files and return the paths written invisibly. If FALSE, return an AsspDataObj. Default FALSE.

explicitExt

Character. Output file extension. Default "ete".

beginTime

Start time for the extracted portion in seconds. Default: NULL (beginning of signal). Note: uses beginTime/endTime (seconds) matching DSP function conventions, unlike read_audio() which uses begin/end.

endTime

The end time of the section of the sound files that should be analysed (in seconds). Use 0 for end of file.

outputDirectory

The directory where the slice file should be stored. If not defiled (NULL), the sparse slice file will placed in the same folder as the media file.

verbose

Logical. Show a progress bar (sequential path) or a progress-aware parallel apply (pbapply/pbmcapply, if installed).

Value

If toFile = FALSE: an AsspDataObj with tracks:

env_te

FLOAT, log10 spectral envelope, n_frames × 513 (DFT size 1024, half-spectrum). Units: log10(amplitude).

env_cc

FLOAT, cepstral coefficients c0…c_{cep_order}, n_frames × (cep_order + 1). Dimensionless.

Frame rate: 1000 / frameShift Hz (default 200 Hz). If toFile = TRUE: character vector of output file paths, returned invisibly.

Details

Envelope is estimated by cepstral liftering: log FFT magnitude is inverse-DFT'd, the top cep_order + 1 cepstral coefficients are kept, and the result is forward-DFT'd to recover a smooth log spectrum.

References

There are no references for Rd macro \insertAllCites on this help page.

Examples

if (FALSE) { # \dontrun{
trk_covarep_env_te(
  system.file("samples", "sustained", "a1.wav", package = "superassp"),
  toFile = FALSE
)
} # }