File size: 4,604 Bytes
4efe6b5
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c02b19
 
 
 
 
 
4efe6b5
 
 
 
 
 
 
 
 
 
 
2c02b19
4efe6b5
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
import torch
import torch.utils.data
from librosa.filters import mel as librosa_mel_fn


def dynamic_range_compression_torch(x, C=1, clip_val=1e-5):
    """
    Dynamic range compression using log10.

    Args:
        x (torch.Tensor): Input tensor.
        C (float, optional): Scaling factor. Defaults to 1.
        clip_val (float, optional): Minimum value for clamping. Defaults to 1e-5.
    """
    return torch.log(torch.clamp(x, min=clip_val) * C)


def dynamic_range_decompression_torch(x, C=1):
    """
    Dynamic range decompression using exp.

    Args:
        x (torch.Tensor): Input tensor.
        C (float, optional): Scaling factor. Defaults to 1.
    """
    return torch.exp(x) / C


def spectral_normalize_torch(magnitudes):
    """
    Spectral normalization using dynamic range compression.

    Args:
        magnitudes (torch.Tensor): Magnitude spectrogram.
    """
    return dynamic_range_compression_torch(magnitudes)


def spectral_de_normalize_torch(magnitudes):
    """
    Spectral de-normalization using dynamic range decompression.

    Args:
        magnitudes (torch.Tensor): Normalized spectrogram.
    """
    return dynamic_range_decompression_torch(magnitudes)


mel_basis = {}
hann_window = {}


def spectrogram_torch(y, n_fft, hop_size, win_size, center=False):
    """
    Compute the spectrogram of a signal using STFT.

    Args:
        y (torch.Tensor): Input signal.
        n_fft (int): FFT window size.
        hop_size (int): Hop size between frames.
        win_size (int): Window size.
        center (bool, optional): Whether to center the window. Defaults to False.
    """
    global hann_window
    dtype_device = str(y.dtype) + "_" + str(y.device)
    wnsize_dtype_device = str(win_size) + "_" + dtype_device
    if wnsize_dtype_device not in hann_window:
        hann_window[wnsize_dtype_device] = torch.hann_window(win_size).to(
            dtype=y.dtype, device=y.device
        )

    y = torch.nn.functional.pad(
        y.unsqueeze(1),
        (int((n_fft - hop_size) / 2), int((n_fft - hop_size) / 2)),
        mode="reflect",
    )
    y = y.squeeze(1)

    # Zluda, fall-back to CPU for FFTs since HIP SDK has no cuFFT alternative
    source_device = y.device
    if y.device.type == "cuda" and torch.cuda.get_device_name().endswith("[ZLUDA]"):
        y = y.to("cpu")
        hann_window[wnsize_dtype_device] = hann_window[wnsize_dtype_device].to("cpu")

    spec = torch.stft(
        y,
        n_fft,
        hop_length=hop_size,
        win_length=win_size,
        window=hann_window[wnsize_dtype_device],
        center=center,
        pad_mode="reflect",
        normalized=False,
        onesided=True,
        return_complex=True,
    ).to(source_device)

    spec = torch.sqrt(spec.real.pow(2) + spec.imag.pow(2) + 1e-6)

    return spec


def spec_to_mel_torch(spec, n_fft, num_mels, sample_rate, fmin, fmax):
    """
    Convert a spectrogram to a mel-spectrogram.

    Args:
        spec (torch.Tensor): Magnitude spectrogram.
        n_fft (int): FFT window size.
        num_mels (int): Number of mel frequency bins.
        sample_rate (int): Sampling rate of the audio signal.
        fmin (float): Minimum frequency.
        fmax (float): Maximum frequency.
    """
    global mel_basis
    dtype_device = str(spec.dtype) + "_" + str(spec.device)
    fmax_dtype_device = str(fmax) + "_" + dtype_device
    if fmax_dtype_device not in mel_basis:
        mel = librosa_mel_fn(
            sr=sample_rate, n_fft=n_fft, n_mels=num_mels, fmin=fmin, fmax=fmax
        )
        mel_basis[fmax_dtype_device] = torch.from_numpy(mel).to(
            dtype=spec.dtype, device=spec.device
        )

    melspec = torch.matmul(mel_basis[fmax_dtype_device], spec)
    melspec = spectral_normalize_torch(melspec)
    return melspec


def mel_spectrogram_torch(
    y, n_fft, num_mels, sample_rate, hop_size, win_size, fmin, fmax, center=False
):
    """
    Compute the mel-spectrogram of a signal.

    Args:
        y (torch.Tensor): Input signal.
        n_fft (int): FFT window size.
        num_mels (int): Number of mel frequency bins.
        sample_rate (int): Sampling rate of the audio signal.
        hop_size (int): Hop size between frames.
        win_size (int): Window size.
        fmin (float): Minimum frequency.
        fmax (float): Maximum frequency.
        center (bool, optional): Whether to center the window. Defaults to False.
    """
    spec = spectrogram_torch(y, n_fft, hop_size, win_size, center)

    melspec = spec_to_mel_torch(spec, n_fft, num_mels, sample_rate, fmin, fmax)

    return melspec