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Ethanfel 6bc3fd6443 chore: vendor selva_core from jnwnlee/selva@d7d40a9
Pure PyTorch SelVA source for SelvaModelLoader/FeatureExtractor/Sampler nodes.
Imports rewritten from selva.* to selva_core.*. mel_converter.py: replaced
librosa.filters.mel with pure-numpy implementation to avoid librosa→numba→NumPy
version incompatibility in some ComfyUI environments.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-04 15:18:09 +02:00

140 lines
4.5 KiB
Python

# Reference: # https://github.com/bytedance/Make-An-Audio-2
from typing import Literal
import numpy as np
import torch
import torch.nn as nn
def librosa_mel_fn(*, sr, n_fft, n_mels=128, fmin=0.0, fmax=None):
"""Pure-numpy mel filterbank equivalent to librosa.filters.mel (HTK scale, no norm).
Replaces the librosa import to avoid the librosa → numba → NumPy-version
incompatibility that exists in some ComfyUI environments.
"""
if fmax is None:
fmax = sr / 2.0
def hz_to_mel(f):
return 2595.0 * np.log10(1.0 + np.asarray(f) / 700.0)
def mel_to_hz(m):
return 700.0 * (10.0 ** (np.asarray(m) / 2595.0) - 1.0)
n_freqs = n_fft // 2 + 1
fft_freqs = np.linspace(0.0, sr / 2.0, n_freqs)
mel_min = hz_to_mel(fmin)
mel_max = hz_to_mel(fmax)
mel_points = np.linspace(mel_min, mel_max, n_mels + 2)
hz_points = mel_to_hz(mel_points)
weights = np.zeros((n_mels, n_freqs), dtype=np.float32)
for m in range(1, n_mels + 1):
f_lo, f_mid, f_hi = hz_points[m - 1], hz_points[m], hz_points[m + 1]
up = (fft_freqs - f_lo) / (f_mid - f_lo + 1e-12)
down = (f_hi - fft_freqs) / (f_hi - f_mid + 1e-12)
weights[m - 1] = np.maximum(0.0, np.minimum(up, down))
return weights
def dynamic_range_compression_torch(x, C=1, clip_val=1e-5, *, norm_fn):
return norm_fn(torch.clamp(x, min=clip_val) * C)
def spectral_normalize_torch(magnitudes, norm_fn):
output = dynamic_range_compression_torch(magnitudes, norm_fn=norm_fn)
return output
class MelConverter(nn.Module):
def __init__(
self,
*,
sampling_rate: float,
n_fft: int,
num_mels: int,
hop_size: int,
win_size: int,
fmin: float,
fmax: float,
norm_fn,
):
super().__init__()
self.sampling_rate = sampling_rate
self.n_fft = n_fft
self.num_mels = num_mels
self.hop_size = hop_size
self.win_size = win_size
self.fmin = fmin
self.fmax = fmax
self.norm_fn = norm_fn
mel = librosa_mel_fn(sr=self.sampling_rate,
n_fft=self.n_fft,
n_mels=self.num_mels,
fmin=self.fmin,
fmax=self.fmax)
mel_basis = torch.from_numpy(mel).float()
hann_window = torch.hann_window(self.win_size)
self.register_buffer('mel_basis', mel_basis)
self.register_buffer('hann_window', hann_window)
@property
def device(self):
return self.mel_basis.device
def forward(self, waveform: torch.Tensor, center: bool = False) -> torch.Tensor:
waveform = waveform.clamp(min=-1., max=1.).to(self.device)
waveform = torch.nn.functional.pad(
waveform.unsqueeze(1),
[int((self.n_fft - self.hop_size) / 2),
int((self.n_fft - self.hop_size) / 2)],
mode='reflect')
waveform = waveform.squeeze(1)
spec = torch.stft(waveform,
self.n_fft,
hop_length=self.hop_size,
win_length=self.win_size,
window=self.hann_window,
center=center,
pad_mode='reflect',
normalized=False,
onesided=True,
return_complex=True)
spec = torch.view_as_real(spec)
spec = torch.sqrt(spec.pow(2).sum(-1) + (1e-9))
spec = torch.matmul(self.mel_basis, spec)
spec = spectral_normalize_torch(spec, self.norm_fn)
return spec
def get_mel_converter(mode: Literal['16k', '44k']) -> MelConverter:
if mode == '16k':
return MelConverter(sampling_rate=16_000,
n_fft=1024,
num_mels=80,
hop_size=256,
win_size=1024,
fmin=0,
fmax=8_000,
norm_fn=torch.log10)
elif mode == '44k':
return MelConverter(sampling_rate=44_100,
n_fft=2048,
num_mels=128,
hop_size=512,
win_size=2048,
fmin=0,
fmax=44100 / 2,
norm_fn=torch.log)
else:
raise ValueError(f'Unknown mode: {mode}')