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150 lines
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Python

import functools
import torch
import torch.utils.data
from librosa.filters import mel as librosa_mel_fn
MAX_WAV_VALUE = 32768.0
def dynamic_range_compression_torch(x, C=1, clip_val=1e-5):
"""
PARAMS
------
C: compression factor
"""
return torch.log(torch.clamp(x, min=clip_val) * C)
def dynamic_range_decompression_torch(x, C=1):
"""
PARAMS
------
C: compression factor used to compress
"""
return torch.exp(x) / C
def spectral_normalize_torch(magnitudes):
return dynamic_range_compression_torch(magnitudes)
def spectral_de_normalize_torch(magnitudes):
return dynamic_range_decompression_torch(magnitudes)
# Reusable banks
@functools.lru_cache(None)
def get_mel_filters(sr: int, n_fft: int, n_mels: int, fmin: float, fmax: float):
return librosa_mel_fn(sr=sr, n_fft=n_fft, n_mels=n_mels, fmin=fmin, fmax=fmax)
@functools.lru_cache(None)
def get_hann_window(win_size: int):
torch.windows.hann
return torch.hann_window(win_size)
def spectrogram_torch(y: torch.Tensor, n_fft: int, hop_size: int, win_size: int, center=False):
"""Convert waveform into Linear-frequency Linear-amplitude spectrogram.
Returns:
:: (B, Freq, Frame) - Linear-frequency Linear-amplitude spectrogram
"""
# Validation
if torch.min(y) < -1.05:
print("min value is ", torch.min(y))
if torch.max(y) > 1.05:
print("max value is ", torch.max(y))
y = y.clamp(min=-1.05, max=1.05)
# Window - Cache if needed
hann_window = get_hann_window(win_size).to(device=y.device)
# Padding
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)
# Complex Spectrogram :: (B, T) -> (B, Freq, Frame, RealComplex=2)
spec = torch.view_as_real(torch.stft(
y.float(),
n_fft,
hop_length=hop_size,
win_length=win_size,
window=hann_window,
center=center,
pad_mode="reflect",
normalized=False,
onesided=True,
return_complex=True,
))
# Linear-frequency Linear-amplitude spectrogram :: (B, Freq, Frame, RealComplex=2) -> (B, Freq, Frame)
spec = torch.sqrt(spec.pow(2).sum(-1) + 1e-8)
return spec.to(device=y.device,dtype=y.dtype)
def spec_to_mel_torch(spec: torch.Tensor, n_fft: int, num_mels: int, sampling_rate: int, fmin: float, fmax: float):
mel = get_mel_filters(sr=sampling_rate, n_fft=n_fft, n_mels=num_mels, fmin=fmin, fmax=fmax)
# Mel-frequency Log-amplitude spectrogram :: (B, Freq=num_mels, Frame)
mel_basis = torch.from_numpy(mel).to(device=spec.device, dtype=spec.dtype)
melspec = torch.matmul(mel_basis, spec)
melspec = spectral_normalize_torch(melspec)
return melspec
# def mel_spectrogram_torch(
# y, n_fft, num_mels, sampling_rate, hop_size, win_size, fmin, fmax, center=False
# ):
# """Convert waveform into Mel-frequency Log-amplitude spectrogram.
# Args:
# y :: (B, T) - Waveforms
# Returns:
# melspec :: (B, Freq, Frame) - Mel-frequency Log-amplitude spectrogram
# """
# # Linear-frequency Linear-amplitude spectrogram :: (B, T) -> (B, Freq, Frame)
# spec = spectrogram_torch(y, n_fft, hop_size, win_size, center)
# # Mel-frequency Log-amplitude spectrogram :: (B, Freq, Frame) -> (B, Freq=num_mels, Frame)
# melspec = spec_to_mel_torch(spec, n_fft, num_mels, sampling_rate, fmin, fmax)
# return melspec
def mel_spectrogram_torch(
wav: torch.Tensor, n_fft: int, n_mels: int, sampling_rate: int, hop_length: int, window_length: int, fmin: float, fmax: float, center=False
):
"""
Mirrors AudioSignal.mel_spectrogram used by BigVGAN-v2 training from:
https://github.com/descriptinc/audiotools/blob/master/audiotools/core/audio_signal.py
"""
B, C, T = wav.shape
# Padding
wav = torch.nn.functional.pad(wav.reshape(-1, T),
(int((n_fft - hop_length) / 2), int((n_fft - hop_length) / 2)),
mode="reflect",
)
window = get_hann_window(window_length).to(device=wav.device)
stft = torch.stft(
wav.float(),
n_fft=n_fft,
hop_length=hop_length,
win_length=window_length,
window=window.float(),
return_complex=True,
center=center,
)
magnitude = torch.abs(stft)
mel_basis = get_mel_filters(sampling_rate, n_fft, n_mels, fmin, fmax)
mel_basis = torch.from_numpy(mel_basis).to(wav.device)
mel_spectrogram = magnitude.transpose(-2, -1) @ mel_basis.T
mel_spectrogram = mel_spectrogram.transpose(-1, -2)
return spectral_normalize_torch(mel_spectrogram).to(dtype=wav.dtype)