Source code for lhotse.dataset.cut_transforms.perturb_speed

import random
from typing import Sequence, Union

from lhotse import CutSet

[docs] class PerturbSpeed: """ A transform on batch of cuts (``CutSet``) that perturbs the speed of the recordings with a given probability :attr:`p`. If the effect is applied, then one of the perturbation factors from the constructor's :attr:`factors` parameter is sampled with uniform probability. """
[docs] def __init__( self, factors: Union[float, Sequence[float]], p: float, randgen: random.Random = None, preserve_id: bool = False, ) -> None: self.factors = factors if isinstance(factors, Sequence) else [factors] self.p = p self.random = randgen self.preserve_id = preserve_id
def __call__(self, cuts: CutSet) -> CutSet: if self.random is None: self.random = random return CutSet.from_cuts( cut.perturb_speed( factor=self.random.choice(self.factors), affix_id=not self.preserve_id ) if self.random.random() <= self.p else cut for cut in cuts )