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Track fundamental frequency using SWIPE (Sawtooth Waveform Inspired Pitch Estimator)

trk_pitch_swipe.Rd

Extracts F0 by matching the speech spectrum against sawtooth waveform templates across candidate F0 values via SPTK. SWIPE is particularly effective for noisy or challenging recording conditions where cross-correlation trackers (RAPT, Snack) are less reliable. Its default voicing threshold (0.3) is lower than RAPT's (0.6), yielding more voiced frames.

Usage

trk_pitch_swipe(listOfFiles, beginTime = 0, endTime = 0, windowShift = 10, minF = 60, maxF = 400, voicing_threshold = 0.3, toFile = TRUE, explicitExt = "f0", outputDirectory = NULL, verbose = TRUE, parallel = NULL, n_cores = NULL)

Arguments

listOfFiles

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

voicing_threshold

Numeric. Voicing decision threshold (0–1). Default 0.3 (more permissive than RAPT). Increase toward 0.5 to reduce false voiced frames.

parallel

Logical. Use parallel processing for multiple files. NULL (default) enables automatically for 2+ files.

n_cores

Integer. Number of cores for parallel processing. NULL (default) uses detectCores() - 1.

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.

windowShift

Numeric. Frame shift in milliseconds; sets output frame rate (1000 / windowShift Hz). Default 5.0 ms (200 Hz). Must be strictly less than 32 ms (the 512-sample analysis window at 16 kHz). Values other than the training default (5 ms) may slightly reduce accuracy.

minF

Numeric. Minimum F0 in Hz for the internal pitch estimator. Lower values allow lower-pitched voices but may increase false positives. Default 40.0 Hz.

maxF

Numeric. Maximum F0 in Hz to treat as voiced. Default 400 Hz (speech). Must be <= 2093.75 Hz (model maximum; C7). For music, use 2093.75.

toFile

Logical. If TRUE, write SSFF output files and return the count written. If FALSE, return an AsspDataObj (single file only). Default TRUE.

explicitExt

By default, a character "d" will be prepended to the file name suffix when writing the output to file. The user can also specify an explicit extension which will be used instead.

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 track:

f0

REAL32, fundamental frequency in Hz, n_frames × 1. Zero indicates unvoiced frames.

Frame rate: 1000 / windowShift Hz (default 100 Hz). If toFile = TRUE: integer count of files written, returned invisibly.

Examples

wav <- system.file("samples", "sustained", "a1.wav", package = "superassp")

# \donttest{
f0 <- trk_pitch_swipe(wav, toFile = FALSE, verbose = FALSE)
head(as.data.frame(f0))
#>   frame_time f0
#> 1       0.00  0
#> 2       0.01  0
#> 3       0.02  0
#> 4       0.03  0
#> 5       0.04  0
#> 6       0.05  0

# Custom range and voicing threshold
trk_pitch_swipe(wav, minF = 100, maxF = 500, voicing_threshold = 0.4,
                toFile = FALSE, verbose = FALSE)
#> In-memory Assp Data Object
#> Format: SSFF (binary)
#> 404 records at 100 Hz
#> Duration: 4.040000 s
#> Number of tracks: 1 
#> 	 f0 (1 fields)
# }