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Track formants using Chirp Group Delay Zero-Phase (CGDZP) analysis

trk_formant_cgdzp.Rd

Estimates formant frequencies from the chirp group delay of a zero-phase processed spectrum with exponential envelope warping (COVAREP implementation). Works well on nasals and fricative transitions where LPC-based trackers (e.g., trk_formant_burg()) struggle because it avoids all-pole model assumptions.

Usage

trk_formant_cgdzp(listOfFiles, beginTime = 0, endTime = 0, frameSize = 30, frameShift = 10, toFile = FALSE, explicitExt = "cgf", 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 10 ms.

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 "cgf".

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:

F1

SHORT (integer), first formant frequency in Hz, n_frames × 1. Zero for unreliable or unvoiced frames.

F2

SHORT, second formant frequency in Hz, n_frames × 1.

F3

SHORT, third formant frequency in Hz, n_frames × 1.

F4

SHORT, fourth formant frequency in Hz, n_frames × 1.

F5

SHORT, fifth formant frequency in Hz, n_frames × 1.

Frame rate: 1000 / frameShift Hz (default 100 Hz). If toFile = TRUE: character vector of output file paths, returned invisibly.

Details

Temporal continuity is enforced with a 250 Hz maximum frame-to-frame jump threshold. The exponential envelope warping factor is adjusted automatically to yield exactly five formant candidates per frame. Frames with fewer than five reliable peaks are filled from adjacent frames; remaining zeros indicate no reliable estimate.

Examples

if (FALSE) { # \dontrun{
# Single file, return object
formants <- trk_formant_cgdzp("speech.wav", toFile = FALSE)

# Batch process multiple files
files <- c("file1.wav", "file2.wav")
trk_formant_cgdzp(files, toFile = TRUE, outputDirectory = "output/")

# Custom frame parameters
formants <- trk_formant_cgdzp("speech.wav",
                             frameSize = 40,
                             frameShift = 5,
                             toFile = FALSE)
} # }