mindspore.dataset.audio.PhaseVocoder

class mindspore.dataset.audio.PhaseVocoder(rate, phase_advance)[source]

Given a STFT spectrogram, speed up in time without modifying pitch by a factor of rate.

Parameters

rate (float) – Speed-up factor.
phase_advance (numpy.ndarray) – Expected phase advance in each bin, in shape of (freq, 1).

Raises

TypeError – If rate is not of type float.
ValueError – If rate is not a positive number.
TypeError – If phase_advance is not of type numpy.ndarray .
RuntimeError – If input tensor is not in shape of <…, freq, num_frame, complex=2>.

Supported Platforms:: CPU

Examples

>>> import numpy as np
>>> import mindspore.dataset as ds
>>> import mindspore.dataset.audio as audio
>>>
>>> waveform = np.random.random([2, 44, 10, 2])
>>> numpy_slices_dataset = ds.NumpySlicesDataset(data=waveform, column_names=["audio"])
>>> phase_advance = np.random.random([44, 1])
>>> transforms = [audio.PhaseVocoder(rate=2, phase_advance=phase_advance)]
>>> numpy_slices_dataset = numpy_slices_dataset.map(operations=transforms, input_columns=["audio"])

Tutorial Examples:

Illustration of audio transforms