Time step (default: 0.01 s)

the measurement interval (frame duration), in seconds.

Very accurate (default: off)

if off, the window is a Hanning window with a length of 3 / (Minimum pitch). If on, the window is a Gaussian window with a length of 6 / (Minimum pitch).

A post-processing algorithm seeks the cheapest path through the candidates. The arguments that determine the cheapest path are:

Silence threshold (default: 0.03)

frames that do not contain amplitudes above this threshold (relative to the global maximum amplitude), are probably silent.

Voicing threshold (default: 0.45)

the strength of the unvoiced candidate, relative to the maximum possible autocorrelation. To increase the number of unvoiced decisions, increase this value.

Octave cost (default: 0.01 per octave)

degree of favouring of high-frequency candidates, relative to the maximum possible autocorrelation. This is necessary because even (or: especially) in the case of a perfectly periodic signal, all undertones of F₀ are equally strong candidates as F₀ itself. To more strongly favour recruitment of high-frequency candidates, increase this value.

Octave-jump cost (default: 0.35)

degree of disfavouring of pitch changes, relative to the maximum possible autocorrelation. To decrease the number of large frequency jumps, increase this value. In contrast with what is described in the article, this value will be corrected for the time step: multiply by 0.01 s / TimeStep to get the value in the way it is used in the formulas in the article.

Voiced / unvoiced cost (default 0.14)

degree of disfavouring of voiced/unvoiced transitions, relative to the maximum possible autocorrelation. to decrease the number of voiced/unvoiced transitions, increase this value. In contrast with what is described in the article, this value will be corrected for the time step: multiply by 0.01 s / TimeStep to get the value in the way it is used in the formulas in the article.