Files
2025-10-08 23:43:27 +03:00

278 lines
10 KiB
Python

from torch import nn
import torch as th
from torch.nn import functional as F
from concurrent.futures import ThreadPoolExecutor
import copy
import random
import tqdm
import typing as tp
from threading import Lock
from .demucs.htdemucs import HTDemucs
from .utils import center_trim, DummyPoolExecutor
Model = tp.Union[HTDemucs]
class BagOfModels(nn.Module):
def __init__(self, models: tp.List[Model],
weights: tp.Optional[tp.List[tp.List[float]]] = None,
segment: tp.Optional[float] = None):
super().__init__()
assert len(models) > 0
first = models[0]
for other in models:
assert other.sources == first.sources
assert other.samplerate == first.samplerate
assert other.audio_channels == first.audio_channels
if segment is not None:
if not isinstance(other, HTDemucs) and segment > other.segment:
other.segment = segment
self.audio_channels = first.audio_channels
self.samplerate = first.samplerate
self.sources = first.sources
self.models = nn.ModuleList(models)
if weights is None:
weights = [[1. for _ in first.sources] for _ in models]
else:
assert len(weights) == len(models)
for weight in weights:
assert len(weight) == len(first.sources)
self.weights = weights
@property
def max_allowed_segment(self) -> float:
max_allowed_segment = float('inf')
for model in self.models:
if isinstance(model, HTDemucs):
max_allowed_segment = min(max_allowed_segment, float(model.segment))
return max_allowed_segment
def forward(self, x):
raise NotImplementedError("Call `apply_model` on this.")
class TensorChunk:
def __init__(self, tensor, offset=0, length=None):
total_length = tensor.shape[-1]
assert offset >= 0
assert offset < total_length
if length is None:
length = total_length - offset
else:
length = min(total_length - offset, length)
if isinstance(tensor, TensorChunk):
self.tensor = tensor.tensor
self.offset = offset + tensor.offset
else:
self.tensor = tensor
self.offset = offset
self.length = length
self.device = tensor.device
@property
def shape(self):
shape = list(self.tensor.shape)
shape[-1] = self.length
return shape
def padded(self, target_length):
delta = target_length - self.length
total_length = self.tensor.shape[-1]
assert delta >= 0
start = self.offset - delta // 2
end = start + target_length
correct_start = max(0, start)
correct_end = min(total_length, end)
pad_left = correct_start - start
pad_right = end - correct_end
out = F.pad(self.tensor[..., correct_start:correct_end], (pad_left, pad_right))
assert out.shape[-1] == target_length
return out
def tensor_chunk(tensor_or_chunk):
if isinstance(tensor_or_chunk, TensorChunk):
return tensor_or_chunk
else:
assert isinstance(tensor_or_chunk, th.Tensor)
return TensorChunk(tensor_or_chunk)
def _replace_dict(_dict: tp.Optional[dict], *subs: tp.Tuple[tp.Hashable, tp.Any]) -> dict:
if _dict is None:
_dict = {}
else:
_dict = copy.copy(_dict)
for key, value in subs:
_dict[key] = value
return _dict
def apply_model(model: tp.Union[BagOfModels, Model],
mix: tp.Union[th.Tensor, TensorChunk],
shifts: int = 1, split: bool = True,
overlap: float = 0.25, transition_power: float = 1.,
progress: bool = False, device=None,
num_workers: int = 0, segment: tp.Optional[float] = None,
pool=None, lock=None,
callback: tp.Optional[tp.Callable[[dict], None]] = None,
callback_arg: tp.Optional[dict] = None) -> th.Tensor:
if device is None:
device = mix.device
else:
device = th.device(device)
if pool is None:
if num_workers > 0 and device.type == 'cpu':
pool = ThreadPoolExecutor(num_workers)
else:
pool = DummyPoolExecutor()
if lock is None:
lock = Lock()
callback_arg = _replace_dict(
callback_arg, *{"model_idx_in_bag": 0, "shift_idx": 0, "segment_offset": 0}.items()
)
kwargs: tp.Dict[str, tp.Any] = {
'shifts': shifts,
'split': split,
'overlap': overlap,
'transition_power': transition_power,
'progress': progress,
'device': device,
'pool': pool,
'segment': segment,
'lock': lock,
}
out: tp.Union[float, th.Tensor]
res: tp.Union[float, th.Tensor]
if isinstance(model, BagOfModels):
# Special treatment for bag of model.
# We explicitely apply multiple times `apply_model` so that the random shifts
# are different for each model.
estimates: tp.Union[float, th.Tensor] = 0.
totals = [0.] * len(model.sources)
callback_arg["models"] = len(model.models)
for sub_model, model_weights in zip(model.models, model.weights):
kwargs["callback"] = ((
lambda d, i=callback_arg["model_idx_in_bag"]: callback(
_replace_dict(d, ("model_idx_in_bag", i))) if callback else None)
)
original_model_device = next(iter(sub_model.parameters())).device
sub_model.to(device)
res = apply_model(sub_model, mix, **kwargs, callback_arg=callback_arg)
out = res
sub_model.to(original_model_device)
for k, inst_weight in enumerate(model_weights):
out[:, k, :, :] *= inst_weight
totals[k] += inst_weight
estimates += out
del out
callback_arg["model_idx_in_bag"] += 1
assert isinstance(estimates, th.Tensor)
for k in range(estimates.shape[1]):
estimates[:, k, :, :] /= totals[k]
return estimates
if "models" not in callback_arg:
callback_arg["models"] = 1
model.to(device)
model.eval()
assert transition_power >= 1, "transition_power < 1 leads to weird behavior."
print(mix)
batch, channels, length = mix.shape
if shifts:
kwargs['shifts'] = 0
max_shift = int(0.5 * model.samplerate)
mix = tensor_chunk(mix)
assert isinstance(mix, TensorChunk)
padded_mix = mix.padded(length + 2 * max_shift)
out = 0.
for shift_idx in range(shifts):
offset = random.randint(0, max_shift)
shifted = TensorChunk(padded_mix, offset, length + max_shift - offset)
kwargs["callback"] = (
(lambda d, i=shift_idx: callback(_replace_dict(d, ("shift_idx", i)))
if callback else None)
)
res = apply_model(model, shifted, **kwargs, callback_arg=callback_arg)
shifted_out = res
out += shifted_out[..., max_shift - offset:]
out /= shifts
assert isinstance(out, th.Tensor)
return out
elif split:
kwargs['split'] = False
out = th.zeros(batch, len(model.sources), channels, length, device=mix.device)
sum_weight = th.zeros(length, device=mix.device)
if segment is None:
segment = model.segment
assert segment is not None and segment > 0.
segment_length: int = int(model.samplerate * segment)
stride = int((1 - overlap) * segment_length)
offsets = range(0, length, stride)
scale = float(format(stride / model.samplerate, ".2f"))
weight = th.cat([th.arange(1, segment_length // 2 + 1, device=device),
th.arange(segment_length - segment_length // 2, 0, -1, device=device)])
assert len(weight) == segment_length
weight = (weight / weight.max())**transition_power
futures = []
for offset in offsets:
chunk = TensorChunk(mix, offset, segment_length)
future = pool.submit(apply_model, model, chunk, **kwargs, callback_arg=callback_arg,
callback=(lambda d, i=offset:
callback(_replace_dict(d, ("segment_offset", i)))
if callback else None))
futures.append((future, offset))
offset += segment_length
if progress:
futures = tqdm.tqdm(futures, unit_scale=scale, ncols=120, unit='seconds')
for future, offset in futures:
try:
chunk_out = future.result() # type: th.Tensor
except Exception:
pool.shutdown(wait=True, cancel_futures=True)
raise
chunk_length = chunk_out.shape[-1]
out[..., offset:offset + segment_length] += (
weight[:chunk_length] * chunk_out).to(mix.device)
sum_weight[offset:offset + segment_length] += weight[:chunk_length].to(mix.device)
assert sum_weight.min() > 0
out /= sum_weight
assert isinstance(out, th.Tensor)
return out
else:
valid_length: int
if isinstance(model, HTDemucs) and segment is not None:
valid_length = int(segment * model.samplerate)
elif hasattr(model, 'valid_length'):
valid_length = model.valid_length(length) # type: ignore
else:
valid_length = length
mix = tensor_chunk(mix)
assert isinstance(mix, TensorChunk)
padded_mix = mix.padded(valid_length).to(device)
with lock:
if callback is not None:
callback(_replace_dict(callback_arg, ("state", "start"))) # type: ignore
with th.no_grad():
out = model(padded_mix)
with lock:
if callback is not None:
callback(_replace_dict(callback_arg, ("state", "end"))) # type: ignore
assert isinstance(out, th.Tensor)
return center_trim(out, length)