pathfinding_fast: Path through pitch candidates: fast

In soundgen: Sound Synthesis and Acoustic Analysis

Path through pitch candidates: fast

Description

Internal soundgen function.

Usage

pathfinding_fast(
  pitchCands,
  pitchCert,
  pitchSource,
  step,
  pitchCenterGravity,
  certWeight,
  seed_ms = 250,
  plot = FALSE
)

Arguments

pitchCands	a matrix of multiple pitch candidates per fft frame. Each column is one fft frame, each row is one candidate (the last row is always "manual")
pitchCert	a matrix of the same dimensionality as pitchCands specifying our certainty in pitch candidates
step	you can override overlap by specifying FFT step, ms (NB: because digital audio is sampled at discrete time intervals of 1/samplingRate, the actual step and thus the time stamps of STFT frames may be slightly different, eg 24.98866 instead of 25.0 ms)
pitchCenterGravity	numeric vector giving the mean of all pitch candidates per fft frame weighted by our certainty in each of these candidates
certWeight	(0 to 1) in pitch postprocessing, specifies how much we prioritize the certainty of pitch candidates vs. pitch jumps / the internal tension of the resulting pitch curve
seed_ms	start a new seed roughly every ... ms
plot	if TRUE, plots pitch candidates and explored paths

Details

Uses a modified Viterbi algorithm to find a reasonable path though pitch candidates. The idea is to start at several random "seeds", each time exploring as many paths as there are candidates per seed. The path with the lowest global cost is returned. Transition costs are a weighted mean of two penalties: based on pitch certainties (corrected for distance from pitch center of gravity) and on pitch jumps.

soundgen documentation built on Sept. 12, 2024, 6:29 a.m.