def __init__(self, model_dir, params, device=torch.device('cuda')):
# Lazy load model.
if not model_dir in models:
if os.path.exists(f'{model_dir}/weights.pt'):
checkpoint = torch.load(f'{model_dir}/weights.pt')
else:
weights_path = maybe_download_weights_from_s3(model_dir)
checkpoint = torch.load(weights_path)
# checkpoint = torch.load(model_dir)
model = WaveGrad(AttrDict(base_params)).to(device)
model.load_state_dict(checkpoint['model'])
model.eval()
models[model_dir] = model
model = models[model_dir]
model.params.override(params)
beta = np.array(model.params.noise_schedule)
alpha = 1 - beta
alpha_cum = np.cumprod(alpha)
self.alpha = alpha
self.alpha_cum = alpha_cum
self.beta = beta
self.model = model
self.device = device
def predict(spectrogram,
model_dir=None,
params=None,
device=torch.device('cuda')):
# Lazy load model.
if not model_dir in models:
if os.path.exists(f'{model_dir}/weights.pt'):
checkpoint = torch.load(f'{model_dir}/weights.pt')
else:
checkpoint = torch.load(model_dir,
map_location=torch.device('cpu'))
model = WaveGrad(AttrDict(base_params)).to(device)
model.load_state_dict(checkpoint['model'])
model.eval()
models[model_dir] = model
model = models[model_dir]
model.params.override(params)
with torch.no_grad():
beta = np.array(model.params.noise_schedule)
alpha = 1 - beta
alpha_cum = np.cumprod(alpha)
# Expand rank 2 tensors by adding a batch dimension.
if len(spectrogram.shape) == 2:
spectrogram = spectrogram.unsqueeze(0)
spectrogram = spectrogram.to(device)
audio = torch.randn(spectrogram.shape[0],
model.params.hop_samples * spectrogram.shape[-1],
device=device)
noise_scale = torch.from_numpy(
alpha_cum**0.5).float().unsqueeze(1).to(device)
for n in range(len(alpha) - 1, -1, -1):
c1 = 1 / alpha[n]**0.5
c2 = (1 - alpha[n]) / (1 - alpha_cum[n])**0.5
audio = c1 * (audio - c2 *
model(audio, spectrogram, noise_scale[n]).squeeze(1))
if n > 0:
noise = torch.randn_like(audio)
sigma = ((1.0 - alpha_cum[n - 1]) / (1.0 - alpha_cum[n]) *
beta[n])**0.5
audio += sigma * noise
audio = torch.clamp(audio, -1.0, 1.0)
return audio, model.params.sample_rate
def load_model(model_dir, params=None, device=torch.device('cuda')):
# Lazy load model.
if not model_dir in models:
if os.path.exists(f'{model_dir}/weights.pt'):
checkpoint = torch.load(f'{model_dir}/weights.pt')
else:
checkpoint = torch.load(model_dir)
model = WaveGrad(AttrDict(base_params)).to(device)
state_dict = checkpoint['model']
new_state_dict = {}
for key in state_dict:
new_state_dict[key.replace("module.", "")] = state_dict[key]
model.load_state_dict(new_state_dict)
model.eval()
models[model_dir] = model
model = models[model_dir]
model.params.override(params)
return model
def predict(spectrogram,
model_dir=None,
params=None,
device=torch.device('cuda'),
audio=None,
severity=None):
# Lazy load model.
if not model_dir in models:
if os.path.exists(f'{model_dir}/weights.pt'):
checkpoint = torch.load(f'{model_dir}/weights.pt')
else:
checkpoint = torch.load(model_dir)
model = WaveGrad(AttrDict(base_params)).to(device)
model.load_state_dict(checkpoint['model'])
model.eval()
models[model_dir] = model
model = models[model_dir]
model.params.override(params)
with torch.no_grad():
beta = np.array(model.params.noise_schedule)
alpha = 1 - beta
alpha_cum = np.cumprod(alpha)
if severity is None:
severity = len(model.params.noise_schedule)
alpha = alpha[-severity:]
alpha_cum = alpha_cum[-severity:]
# Expand rank 2 tensors by adding a batch dimension.
if len(spectrogram.shape) == 2:
spectrogram = spectrogram.unsqueeze(0)
spectrogram = spectrogram.to(device)
length = model.params.hop_samples * spectrogram.shape[-1]
if audio is None:
audio = torch.randn(spectrogram.shape[0], length, device=device)
else:
# TODO FROME HERE: padding or truncation
if audio.shape[-1] > length:
audio = audio[..., :length]
else:
audio = audio.to(device)
padding = (torch.zeros(
[audio.shape[0], length - audio.shape[1]]).to(device))
audio = torch.cat([audio, padding], -1)
noise_scale = torch.from_numpy(
alpha_cum**0.5).float().unsqueeze(1).to(device)
ti = time()
for n in range(severity - 1, -1, -1):
print(f"{n}/{len(alpha)}", end="\r")
c1 = 1 / alpha[n]**0.5
c2 = (1 - alpha[n]) / (1 - alpha_cum[n])**0.5
prediction = model(audio, spectrogram, noise_scale[n]).squeeze(1)
audio = c1 * (audio - c2 * prediction)
if n > 0:
noise = torch.randn_like(audio)
sigma = ((1.0 - alpha_cum[n - 1]) / (1.0 - alpha_cum[n]) *
beta[n])**0.5
audio += sigma * noise
audio = torch.clamp(audio, -1.0,
1.0) # TODO: J: I disagree with this step
print(f"\nFinished {spectrogram.shape} in {time() - ti:.2f} secs.")
return audio, model.params.sample_rate