def test_serialize_deserialize_transform_speed(audio):
speed_orig = Speed(factor=1.1)
data_speed = speed_orig.to_dict()
speed = AudioTransform.from_dict(data_speed)
perturbed_speed = speed(audio, SAMPLING_RATE)
assert perturbed_speed.shape == (1, 14545)
def perturb_speed(self, factor: float, affix_id: bool = True) -> 'Recording':
"""
Return a new ``Recording`` that will lazily perturb the speed while loading audio.
The ``num_samples`` and ``duration`` fields are updated to reflect the
shrinking/extending effect of speed.
:param factor: The speed will be adjusted this many times (e.g. factor=1.1 means 1.1x faster).
:param affix_id: When true, we will modify the ``Recording.id`` field
by affixing it with "_sp{factor}".
:return: a modified copy of the current ``Recording``.
"""
transforms = self.transforms if self.transforms is not None else []
transforms.append(Speed(factor=factor).to_dict())
new_num_samples = perturb_num_samples(self.num_samples, factor)
new_duration = new_num_samples / self.sampling_rate
return fastcopy(
self,
id=f'{self.id}_sp{factor}' if affix_id else self.id,
num_samples=new_num_samples,
duration=new_duration,
transforms=transforms
)
def test_speed(audio):
speed = Speed(factor=1.1)
perturbed = speed(audio, SAMPLING_RATE)
assert perturbed.shape == (1, 14545)