def forward(self, signal, threshs_file):
if self.phi is None:
return signal
# fft
complex_spectrum = torch.stft(signal,
n_fft=self.win_length,
hop_length=self.hop_length,
win_length=self.win_length,
window=torch.hamming_window(
self.win_length),
pad_mode='constant',
onesided=True)
# mask signal with psychoacoustic thresholds
mask = self.get_psycho_mask(complex_spectrum, threshs_file)
complex_spectrum_masked = complex_spectrum * mask
# ifft
signal_out = torch.istft(complex_spectrum_masked,
n_fft=self.win_length,
hop_length=self.hop_length,
win_length=self.win_length,
window=torch.hamming_window(self.win_length),
onesided=True)
return signal_out
def test_pwelch(random_state):
from cplxmodule.utils.spectrum import pwelch
from scipy.signal import welch
# https://www.mathworks.com/help/signal/ref/pwelch.html#btulskp-6
fs = 1000.
tt = np.r_[:5 * fs - 1] / fs
shape = 2, len(tt)
epsilon = random_state.randn(*shape) + 1j * random_state.randn(*shape)
np_x = np.cos(2 * np.pi * 100 * tt)[np.newaxis] + epsilon * 0.01
tr_x = torch.tensor(np.stack([np_x.real, np_x.imag], axis=-1))
tr_x.requires_grad = False
tr_window = torch.hamming_window(500, periodic=False, dtype=tr_x.dtype)
tr_ff, tr_px = pwelch(tr_x, 1, tr_window, fs=fs,
scaling="density", n_overlap=300)
np_ff, np_px = welch(np_x, fs=fs, axis=-1, window=tr_window.numpy(),
nfft=None, nperseg=None, scaling="density",
noverlap=300, detrend=False, return_onesided=False)
assert torch.allclose(tr_px, torch.from_numpy(np_px))
assert torch.allclose(tr_ff, torch.from_numpy(np_ff))
tr_ff, tr_px = pwelch(tr_x, 1, tr_window, fs=fs,
scaling="spectrum", n_overlap=499)
np_ff, np_px = welch(np_x, fs=fs, axis=-1, window=tr_window.numpy(),
nfft=None, nperseg=None, scaling="spectrum",
noverlap=499, detrend=False, return_onesided=False)
assert torch.allclose(tr_px, torch.from_numpy(np_px))
assert torch.allclose(tr_ff, torch.from_numpy(np_ff))
def get_spectrogram_feature(self, signal):
spectrogram = torch.stft(
torch.FloatTensor(signal),
self.n_fft,
hop_length=self.hop_length,
win_length=self.n_fft,
window=torch.hamming_window(self.n_fft),
center=False,
normalized=False,
onesided=True
)
spectrogram = (spectrogram[:, :, 0].pow(2) + spectrogram[:, :, 1].pow(2)).pow(0.5)
spectrogram = np.log1p(spectrogram.numpy())
# Refer to "Sequence to Sequence Learning with Neural Network" paper
if self.input_reverse:
spectrogram = spectrogram[:, ::-1]
spectrogram = torch.FloatTensor(np.ascontiguousarray(np.swapaxes(spectrogram, 0, 1)))
else:
spectrogram = torch.FloatTensor(spectrogram).transpose(0, 1)
if self.normalize:
spectrogram -= spectrogram.mean()
return spectrogram
def get_window(window_type: str,
window_length_in_samp: int,
device: Optional[torch.device] = None) -> torch.Tensor:
# Increase precision in order to achieve parity with scipy.signal.windows.get_window implementation
if window_type == "bartlett":
return torch.bartlett_window(window_length_in_samp,
periodic=False,
dtype=torch.float64,
device=device).to(torch.float32)
elif window_type == "blackman":
return torch.blackman_window(window_length_in_samp,
periodic=False,
dtype=torch.float64,
device=device).to(torch.float32)
elif window_type == "hamming":
return torch.hamming_window(window_length_in_samp,
periodic=False,
dtype=torch.float64,
device=device).to(torch.float32)
elif window_type == "hann":
return torch.hann_window(window_length_in_samp,
periodic=False,
dtype=torch.float64,
device=device).to(torch.float32)
else:
raise ValueError(f"Unknown window type: {window_type}")
def test_hamming_window(random_state=None):
from scipy.signal.windows import hamming
n_window = 1024
np_window = hamming(n_window, False).astype(np.float64)
tr_window = torch.hamming_window(n_window, periodic=True,
dtype=torch.float64)
assert torch.allclose(tr_window, torch.from_numpy(np_window))
np_window = hamming(n_window, True).astype(np.float64)
tr_window = torch.hamming_window(n_window, periodic=False,
dtype=torch.float64)
assert torch.allclose(tr_window, torch.from_numpy(np_window))
def _feature_window_function(window_type: str, window_size: int,
blackman_coeff: float, device: str) -> Tensor:
r"""Returns a window function with the given type and size
"""
if window_type == HANNING:
window = torch.hann_window(window_size, periodic=False)
elif window_type == HAMMING:
window = torch.hamming_window(window_size,
periodic=False,
alpha=0.54,
beta=0.46)
elif window_type == POVEY:
# like hanning but goes to zero at edges
window = torch.hann_window(window_size, periodic=False).pow(0.85)
elif window_type == RECTANGULAR:
window = torch.ones(window_size)
elif window_type == BLACKMAN:
a = 2 * math.pi / (window_size - 1)
window_function = torch.arange(window_size)
# can't use torch.blackman_window as they use different coefficients
window = (blackman_coeff - 0.5 * torch.cos(a * window_function) +
(0.5 - blackman_coeff) * torch.cos(2 * a * window_function))
else:
raise Exception('Invalid window type ' + window_type)
return window.to(device)
def overlap_add(mel_frames, nmels):
# Hamming windows used for overlap add
hamm = torch.hamming_window(160, periodic=False)
half_hamm = torch.cat((torch.ones(80), hamm[80:]), dim=0)
hamm.unsqueeze_(1)
half_hamm.unsqueeze_(1)
time = (1 + len(mel_frames)) * 80
recon = torch.zeros((time, nmels))
ind = torch.arange(160) - 80
for i in range(len(mel_frames)):
frame = mel_frames[i]
if frame.shape[1] != nmels:
frame = frame.permute(1, 0)
ind += 80
if i == 0:
recon[ind, :] += frame * half_hamm
elif i == len(mel_frames) - 1:
recon[ind, :] += frame * torch.flip(half_hamm, dims=(0, ))
else:
recon[ind, :] += frame * hamm
return recon
def torch_spec2wav(self, spectrogram, phase=None):
spectrogram = spectrogram.transpose(2, 1)
phase = phase.transpose(2, 1)
# denormalise spectrogram
S = (torch.clamp(spectrogram, 0.0, 1.0) - 1.0) * -self.min_level_db
S = S + self.ref_level_db
# db_to_amp
stft_matrix = torch.pow(10.0, S * 0.05)
# invert phase
phase = torch.stack([phase.cos(), phase.sin()],
dim=-1).to(dtype=stft_matrix.dtype,
device=stft_matrix.device)
stft_matrix = stft_matrix.unsqueeze(-1).expand_as(phase)
return torchaudio.functional.istft(
stft_matrix * torch.exp(phase),
self.n_fft,
hop_length=self.hop_length,
win_length=self.win_length,
window=torch.hamming_window(
self.win_length, periodic=False, alpha=0.5,
beta=0.5).to(device=stft_matrix.device),
center=True,
normalized=False,
onesided=True,
length=None)
def get_spectrogram_feature(filepath):
(rate, width, sig) = wavio.readwav(filepath)
sig = sig.ravel()
# sig, _ = librosa.effects.trim(sig.astype(np.float32))
valid_pos = np.where(sig > MIN_SIGNAL_VALUE)[0]
sig = sig[valid_pos[0]:valid_pos[-1]]
if len(sig) > MAX_SIGNAL_LENGTH:
sig = sig[:MAX_SIGNAL_LENGTH]
stft = torch.stft(torch.FloatTensor(sig),
N_FFT,
hop_length=int(0.01*SAMPLE_RATE),
win_length=int(0.030*SAMPLE_RATE),
window=torch.hamming_window(int(0.030*SAMPLE_RATE)),
center=False,
normalized=False,
onesided=True)
stft = (stft[:,:,0].pow(2) + stft[:,:,1].pow(2)).pow(0.5);
amag = stft.numpy();
feat = torch.FloatTensor(amag)
feat = torch.FloatTensor(feat).transpose(0, 1)
return feat
def get_window(name, window_length, squared=False):
"""
Returns a windowing function.
Arguments:
----------
window (str) : name of the window, currently only 'hann' is available
window_length (int) : length of the window
squared (bool) : if true, square the window
Returns:
----------
torch.FloatTensor : window of size `window_length`
"""
if name == "hann":
window = torch.hann_window(window_length)
elif name == "hamming":
window = torch.hamming_window(window_length)
elif name == "blackman":
window = torch.blackman_window(window_length)
else:
raise ValueError("Invalid window name {}".format(name))
if squared:
window *= window
return window
def sinc_impulse_response(cutoff_frequency, window_size=512, sample_rate=None):
"""Get a sinc impulse response for a set of low-pass cutoff frequencies.
Args:
cutoff_frequency: Frequency cutoff for low-pass sinc filter. If the
sample_rate is given, cutoff_frequency is in Hertz. If sample_rate
is None, cutoff_frequency is normalized ratio (frequency/nyquist)
in the range [0, 1.0]. Shape [batch_size, n_time, 1].
window_size: Size of the Hamming window to apply to the impulse.
sample_rate: Optionally provide the sample rate.
Returns:
impulse_response: A series of impulse responses. Shape
[batch_size, n_time, (window_size // 2) * 2 + 1].
"""
if sample_rate is not None:
cutoff_frequency *= 2 / sample_rate
half_size = window_size // 2
full_size = half_size * 2 + 1
idx = th.arange(-half_size, half_size + 1, dtype=th.float)[None, None, :]
impulse_response = sinc(cutoff_frequency * idx)
window = th.hamming_window(full_size).expand_as(impulse_response)
impulse_response = window * th.real(impulse_response)
return impulse_response / impulse_response.sum(-1, keepdim=True)
def __getitem__(self, idx):
noisy_path = self.noisy_WAVs[idx]
clean_path = self.clean_dir.joinpath(noisy_path.name.split('+')[0] + '.wav') # get the filename of the clean WAV from the filename of the noisy WAV
while True:
try:
clean_waveform, _ = torchaudio.load(clean_path, normalization=2**15)
noisy_waveform, _ = torchaudio.load(noisy_path, normalization=2**15)
except (RuntimeError, OSError):
continue
break
assert clean_waveform.shape[0] == 1 and noisy_waveform.shape[0] == 1, 'WAV file is not single channel!'
window = torch.hamming_window(self.n_fft)
x_stft = torch.stft(noisy_waveform.view(-1), n_fft=self.n_fft, hop_length=self.n_fft // 4, win_length=self.n_fft, window=window)
y_stft = torch.stft(clean_waveform.view(-1), n_fft=self.n_fft, hop_length=self.n_fft // 4, win_length=self.n_fft, window=window)
x_ps = x_stft.pow(2).sum(-1)
x_lps = LogTransform()(x_ps)
x_ms = x_ps.sqrt()
y_ms = y_stft.pow(2).sum(-1).sqrt()
noise_ms = (x_stft - y_stft).pow(2).sum(-1).sqrt()
# VAD
y_ms_filtered = y_ms[self.VAD_frequencies]
y_energy_filtered = y_ms_filtered.pow(2).mean(dim=0)
y_energy_filtered_averaged = self.__moving_average(y_energy_filtered)
y_peak_energy = y_energy_filtered_averaged.max()
VAD = torch.where(y_energy_filtered_averaged > y_peak_energy / 1000, torch.ones_like(y_energy_filtered), torch.zeros_like(y_energy_filtered))
VAD = VAD.bool()
# mean normalization
frames = []
x_lps = x_lps.transpose(0, 1) # (time, frequency)
n_init_frames = self.n_init_frames
alpha_feat_init = self.alpha_feat_init
alpha_feat = self.alpha_feat
for frame_counter, frame_feature in enumerate(x_lps):
if frame_counter < n_init_frames:
alpha = alpha_feat_init
else:
alpha = alpha_feat
if frame_counter == 0:
mu = frame_feature
sigmasquare = frame_feature.pow(2)
mu = alpha * mu + (1 - alpha) * frame_feature
sigmasquare = alpha * sigmasquare + (1 - alpha) * frame_feature.pow(2)
sigma = torch.sqrt(torch.clamp(sigmasquare - mu.pow(2), min=1e-12)) # limit for sqrt
norm_feature = (frame_feature - mu) / sigma
frames.append(norm_feature)
x_lps = torch.stack(frames, dim=0).transpose(0, 1) # (frequency, time)
if not self.test:
return x_lps, x_ms, y_ms, noise_ms, VAD
if self.test:
return noisy_waveform.view(-1), clean_waveform.view(-1), x_stft, y_stft, x_lps, x_ms, y_ms, VAD
def __init__(self, win_length, hop_length=None, n_fft=None):
super().__init__()
self.window = torch.hamming_window(win_length)
if hop_length is None:
hop_length = win_length // 4
if n_fft is None:
n_fft = win_length
self.hop_length = hop_length
self.n_fft = n_fft
def _get_feature(self, signal: np.ndarray) -> np.ndarray:
spectrogram = torch.stft(
Tensor(signal), self.n_fft, hop_length=self.hop_length,
win_length=self.n_fft, window=torch.hamming_window(self.n_fft),
center=False, normalized=False, onesided=True
)
spectrogram = (spectrogram[:, :, 0].pow(2) + spectrogram[:, :, 1].pow(2)).pow(0.5)
spectrogram = np.log1p(spectrogram.numpy())
return spectrogram
def get_torch_spectrogram(filepath, sr=16000, window_size=20, stride=10):
r"""
get a spectrogram by torch.
Args: filepath, n_mels, del_silence, input_reverse, normalize, sr, wiindow_size, stride
filepath (str): specific path of audio file
sr (int): sample rate
window_size (int): window size (ms)
stride (int): forwarding size (ms)
Returns: spectrogram
- **spectrogram** (torch.Tensor): return Spectrogram feature
Examples::
Generate mel spectrogram from a time series
>>> get_torch_spectrogram(filepath)
Tensor([[ 2.891e-07, 2.548e-03, ..., 8.116e-09, 5.633e-09],
[ 1.986e-07, 1.162e-02, ..., 9.332e-08, 6.716e-09],
...,
[ 3.668e-09, 2.029e-08, ..., 3.208e-09, 2.864e-09],
[ 2.561e-10, 2.096e-09, ..., 7.543e-10, 6.101e-10]])
"""
if filepath.endswith('.pcm'):
try:
pcm = np.memmap(filepath, dtype='h', mode='r')
except RuntimeError:
logger.info('RuntimeError in {0}'.format(filepath))
return None
signal = np.array([float(x) for x in pcm])
elif filepath.endswith('.wav'):
signal, _ = librosa.core.load(filepath, sr=sr)
else:
raise ValueError("Unsupported format: {0}".format(
filepath.split('.')[-1]))
N_FFT = int(sr * 0.001 * window_size)
STRIDE = int(sr * 0.001 * stride)
spectrogram = torch.stft(torch.FloatTensor(signal),
N_FFT,
hop_length=STRIDE,
win_length=N_FFT,
window=torch.hamming_window(N_FFT),
center=False,
normalized=False,
onesided=True)
spectrogram = (spectrogram[:, :, 0].pow(2) +
spectrogram[:, :, 1].pow(2)).pow(0.5) # (N_FFT / 2 + 1 * T)
spectrogram = np.log1p(spectrogram.numpy())
spectrogram = torch.FloatTensor(spectrogram).transpose(0, 1)
spectrogram -= spectrogram.mean()
return spectrogram
def get_window(window_size, window_type, square_root_window=True):
"""Return the window"""
window = {
'hamming': torch.hamming_window(window_size),
'hanning': torch.hann_window(window_size),
}[window_type]
if square_root_window:
window = torch.sqrt(window)
return window
def build_window(fft_size, window_fn='hann'):
if window_fn == 'hann':
window = torch.hann_window(fft_size, periodic=True)
elif window_fn == 'hamming':
window = torch.hamming_window(fft_size, periodic=True)
else:
raise ValueError("Not support {} window.".format(window_fn))
return window
def __call__(self, signal):
with torch.no_grad():
torch_signal = torch.Tensor(signal).unsqueeze(0)
wave = torch_signal.to(self.device)
stft_noisy_mag, stft_noisy_phase = torchaudio.functional.magphase(
torch.stft(wave,
n_fft=self.nfft,
hop_length=self.hop_len,
win_length=self.window_len,
window=torch.hamming_window(self.window_len).to(
self.device)))
stft_input_mag = torch.transpose(stft_noisy_mag.clone(), 2,
1).cpu().numpy()
stft_input_power = stft_input_mag[0]**2
smallpower = stft_input_power < self.eps
stft_input_power[smallpower] = np.log(self.eps)
stft_input_power[~smallpower] = np.log(
stft_input_power[~smallpower])
stft_input_power = self.norm_function(stft_input_power)
stft_input_power = torch.FloatTensor(stft_input_power).to(
self.device)
mask = self.model(stft_input_power.unsqueeze(0))
enhanced_mag = torch.transpose(mask, 2, 1) * stft_noisy_mag
complex_enhanced = torch.zeros(
(enhanced_mag.shape[0], enhanced_mag.shape[1],
enhanced_mag.shape[2], 2))
complex_enhanced[:, :, :,
0] = enhanced_mag * torch.cos(stft_noisy_phase)
complex_enhanced[:, :, :,
1] = enhanced_mag * torch.sin(stft_noisy_phase)
enhanced_sig_recon = torch.istft(complex_enhanced,
n_fft=self.nfft,
hop_length=self.hop_len,
win_length=self.window_len,
window=torch.hamming_window(
self.window_len))
return enhanced_sig_recon
def get_spectrogram_feature(cfg_data, filepath, train_mode=False):
use_mel_scale = cfg_data["use_mel_scale"]
cfg_spec_augment = cfg_data["spec_augment"]
use_specaug = cfg_spec_augment["use"]
cfg_trim = cfg_data["trim_silence"]
use_trim = cfg_trim["use"]
(rate, width, sig) = wavio.readwav(filepath)
sig = sig.ravel()
if use_trim:
sig = trim.trim(sig, cfg_trim)
stft = torch.stft(torch.FloatTensor(sig),
N_FFT,
hop_length=int(0.01 * SAMPLE_RATE),
win_length=int(0.030 * SAMPLE_RATE),
window=torch.hamming_window(int(0.030 * SAMPLE_RATE)),
center=False,
normalized=False,
onesided=True)
stft = (stft[:, :, 0].pow(2) + stft[:, :, 1].pow(2)).pow(0.5)
if use_mel_scale:
amag = stft.clone().detach()
amag = amag.view(
-1, amag.shape[0], amag.shape[1]
) # reshape spectrogram shape to [batch_size, time, frequency]
mel = melscale_pytorch.mel_scale(amag,
sample_rate=SAMPLE_RATE,
n_mels=N_FFT // 2 +
1) # melspec with same shape
if use_specaug and train_mode:
specaug_prob = 1 # augment probability
if numpy.random.uniform(0, 1) < specaug_prob:
# apply augment
mel = spec_augment_pytorch.spec_augment(
mel,
time_warping_para=80,
frequency_masking_para=54,
time_masking_para=40,
frequency_mask_num=1,
time_mask_num=1)
feat = mel.view(mel.shape[1],
mel.shape[2]) # squeeze back to [frequency, time]
feat = feat.transpose(0, 1).clone().detach()
del sig, stft, amag, mel
else:
# use baseline feature
amag = stft.numpy()
feat = torch.FloatTensor(amag)
feat = torch.FloatTensor(feat).transpose(0, 1)
del sig, stft, amag
return feat
def periodogram(signal,
window_fn=torch.hann_window,
is_train=False): # not used
if window_fn is not None:
signal = signal * torch.hamming_window(window_length=signal.size(-1),
periodic=False,
device=signal.device)
if not is_train:
with torch.no_grad():
dft = torch.rfft(signal, signal_ndim=1, onesided=True)
return torch.pow(dft, 2).sum(-1)
def pre_process(self, data, data_length):
# ToDo - write the code for generating pitch features
fbank = self.fbank[data.get_device()]
pre_emphasis = config.fbank['pre_emphasis']
frame_size = config.fbank['frame_size']
frame_stride = config.fbank['frame_stride']
n_fft = config.fbank['n_fft']
rate = config.fbank['rate']
emphasized_data = torch.zeros_like(data).float()
if config.use_cuda:
emphasized_data = emphasized_data.to(data.device)
emphasized_data[:, 1:] = data[:, 1:] - pre_emphasis * data[:, :-1]
emphasized_data[:, 0] = data[:, 0]
frame_length, frame_step = frame_size * rate, frame_stride * rate # Convert from seconds to samples
frame_length = int(frame_length)
frame_step = int(frame_step)
mag_frames = torch.norm(torch.stft(
emphasized_data,
n_fft=n_fft,
hop_length=frame_step,
win_length=frame_length,
window=torch.hamming_window(frame_length).to(
emphasized_data.device),
pad_mode='constant'),
dim=3).transpose(2, 1)
pow_frames = ((1.0 / n_fft) * (mag_frames**2)) # Power Spectrum
filter_banks = torch.matmul(pow_frames, fbank.transpose(1, 0))
filter_banks[filter_banks == 0] = 2.220446049250313e-16
filter_banks = 20 * torch.log10(filter_banks) # dB
filter_banks -= (torch.mean(filter_banks, dim=(0, 1), keepdim=True) +
1e-8)
if data_length is None:
ilens = (torch.ones([filter_banks.shape[0]]) *
filter_banks.shape[1]).long()
else:
ilens = torch.FloatTensor([
data_length_i // frame_step + 1
for data_length_i in data_length
]).long()
# for filter_banks.shape[0]
return filter_banks, ilens
def test_linearity_of_istft4(self):
# hamming_window, not centered, not normalized, onesided
kwargs4 = {
'n_fft': 12,
'window': torch.hamming_window(12),
'center': False,
'pad_mode': 'constant',
'normalized': False,
'onesided': True,
}
data_size = (2, 7, 3, 2)
self._test_linearity_of_istft(data_size, kwargs4, atol=1e-5, rtol=1e-8)
def test_linearity_of_istft3(self):
# hamming_window, centered, normalized, not onesided
kwargs3 = {
'n_fft': 12,
'window': torch.hamming_window(12),
'center': True,
'pad_mode': 'constant',
'normalized': True,
'onesided': False,
}
data_size = (2, 12, 7, 2)
self._test_linearity_of_istft(data_size, kwargs3)
def spectral_ops(self):
a = torch.randn(10)
b = torch.randn(10, 8, 4, 2)
return (
torch.stft(a, 8),
torch.istft(b, 8),
torch.bartlett_window(2, dtype=torch.float),
torch.blackman_window(2, dtype=torch.float),
torch.hamming_window(4, dtype=torch.float),
torch.hann_window(4, dtype=torch.float),
torch.kaiser_window(4, dtype=torch.float),
)
def test_istft_is_inverse_of_stft3(self):
# hamming_window, centered, normalized, not onesided
kwargs3 = {
'n_fft': 15,
'hop_length': 3,
'win_length': 11,
'window': torch.hamming_window(11),
'center': True,
'pad_mode': 'constant',
'normalized': True,
'onesided': False,
}
_test_istft_is_inverse_of_stft(kwargs3)
def smooth_upsample2(x, size):
batch, channels, frames = x.shape
hop_size = size // frames
window_size = hop_size * 2
window = torch.hamming_window(window_size, periodic=True).to(x.device)
amps = x.view(batch, channels * frames)
scaled_windows = amps[..., None] * window[None, None, :]
scaled_windows = scaled_windows.view(batch, channels, frames, window_size)
output = overlap_add(scaled_windows, apply_window=False)
output = output[:, :, :-hop_size]
return output
def __init__(self, cutoffs: list, width: int = None):
super().__init__()
self.cutoffs = cutoffs
if width is None:
width = int(2 / min(cutoffs))
self.width = width
window = torch.hamming_window(2 * width + 1, periodic=False)
t = np.arange(-width, width + 1, dtype=np.float32)
filters = []
for cutoff in cutoffs:
sinc = torch.from_numpy(np.sinc(2 * cutoff * t))
filters.append(2 * cutoff * sinc * window)
self.register_buffer("filters", torch.stack(filters).unsqueeze(1))
def get_spectrogram_feature(filepath, train_mode=False):
(rate, width, sig) = wavio.readwav(filepath)
wavio.writewav24("test.wav", rate=rate, data=sig)
sig = sig.ravel()
sig = trim(sig)
stft = torch.stft(torch.FloatTensor(sig),
N_FFT,
hop_length=int(0.01 * SAMPLE_RATE),
win_length=int(0.030 * SAMPLE_RATE),
window=torch.hamming_window(int(0.030 * SAMPLE_RATE)),
center=False,
normalized=False,
onesided=True)
stft = (stft[:, :, 0].pow(2) + stft[:, :, 1].pow(2)).pow(0.5)
amag = stft.clone().detach()
amag = amag.view(
-1, amag.shape[0], amag.shape[1]
) # reshape spectrogram shape to [batch_size, time, frequency]
mel = melscale_pytorch.mel_scale(amag,
sample_rate=SAMPLE_RATE,
n_mels=N_FFT // 2 +
1) # melspec with same shape
plt.subplot(1, 2, 1)
plt.imshow(mel.transpose(1, 2).squeeze(), cmap='jet')
p = 1 # always augment
randp = np.random.uniform(0, 1)
do_aug = p > randp
if do_aug & train_mode: # apply augment
print("augment image")
mel = spec_augment_pytorch.spec_augment(mel,
time_warping_para=80,
frequency_masking_para=54,
time_masking_para=50,
frequency_mask_num=1,
time_mask_num=1)
feat = mel.view(mel.shape[1],
mel.shape[2]) # squeeze back to [frequency, time]
feat = feat.transpose(0, 1).clone().detach()
plt.subplot(1, 2, 2)
plt.imshow(feat, cmap='jet')
plt.show() # display it
del stft, amag, mel
return feat
def forward(self, x):
"""
input:
------
x: tensor(batch, length), where length is waveform length
output:
-------
lfcc_output: tensor(batch, frame_num, dim_num)
"""
# pre-emphsis
if self.with_emphasis:
x[:, 1:] = x[:, 1:] - 0.97 * x[:, 0:-1]
# STFT
x_stft = torch.stft(x,
self.fn,
self.fs,
self.fl,
window=torch.hamming_window(self.fl).to(x.device),
onesided=True,
pad_mode="constant")
# amplitude
sp_amp = torch.norm(x_stft, 2, -1).pow(2).permute(0, 2, 1).contiguous()
# filter bank
fb_feature = torch.log10(
torch.matmul(sp_amp, self.lfcc_fb) +
torch.finfo(torch.float32).eps)
# DCT (if necessary, remove DCT)
lfcc = self.l_dct(fb_feature) if not self.flag_for_LFB else fb_feature
# Add energy
if self.with_energy:
power_spec = sp_amp / self.fn
energy = torch.log10(
power_spec.sum(axis=2) + torch.finfo(torch.float32).eps)
lfcc[:, :, 0] = energy
# Add delta coefficients
if self.with_delta:
lfcc_delta = delta(lfcc)
lfcc_delta_delta = delta(lfcc_delta)
lfcc_output = torch.cat((lfcc, lfcc_delta, lfcc_delta_delta), 2)
else:
lfcc_output = lfcc
# done
return lfcc_output
def test_istft_is_inverse_of_stft5(self):
# hamming_window, not centered, not normalized, not onesided
# window same size as n_fft
kwargs5 = {
'n_fft': 3,
'hop_length': 2,
'win_length': 3,
'window': torch.hamming_window(3),
'center': False,
'pad_mode': 'reflect',
'normalized': False,
'onesided': False,
}
_test_istft_is_inverse_of_stft(kwargs5)
def __init__(self, scale, taps, samplerate):
super(SincLayer, self).__init__()
self.samplerate = int(samplerate)
self.taps = taps
self.scale = scale
# each filter requires two parameters to define the filter bandwidth
filter_parameters = torch.FloatTensor(len(scale), 2)
self.linear = nn.Parameter(
torch.linspace(-math.pi, math.pi, steps=taps), requires_grad=False)
self.window = nn.Parameter(
torch.hamming_window(self.taps), requires_grad=False)
for i, band in enumerate(scale):
start = self.samplerate / band.start_hz
stop = self.samplerate / band.stop_hz
filter_parameters[i, 0] = start
filter_parameters[i, 1] = stop
self.filter_parameters = nn.Parameter(filter_parameters)
