mindspore.dataset.audio.transforms.LowpassBiquad

class mindspore.dataset.audio.transforms.LowpassBiquad(sample_rate, cutoff_freq, Q=0.707)[source]

Design biquad lowpass filter and perform filtering. Similar to SoX implementation.

Parameters

sample_rate (int) – Sampling rate of the waveform, e.g. 44100 (Hz), the value can’t be zero.
cutoff_freq (float) – Filter cutoff frequency.
Q (float, optional) – Quality factor, https://en.wikipedia.org/wiki/Q_factor, range: (0, 1] (default=0.707).

Examples

>>> import numpy as np
>>>
>>> waveform = np.array([[0.8236, 0.2049, 0.3335], [0.5933, 0.9911, 0.2482],
...                      [0.3007, 0.9054, 0.7598], [0.5394, 0.2842, 0.5634], [0.6363, 0.2226, 0.2288]])
>>> numpy_slices_dataset = ds.NumpySlicesDataset(data=waveform, column_names=["audio"])
>>> transforms = [audio.LowpassBiquad(4000, 1500, 0.7)]
>>> numpy_slices_dataset = numpy_slices_dataset.map(operations=transforms, input_columns=["audio"])