refactor: rename canto-backend → backend, canto-frontend → frontend

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
This commit is contained in:
2026-04-07 18:11:00 +08:00
parent 2fa9c1fcb6
commit 60489eab59
327 changed files with 0 additions and 0 deletions

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# Copyright (c) 2023 Amphion.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
# This source file is copied from https://github.com/facebookresearch/encodec
# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the license found in the
# LICENSE file in the root directory of this source tree.
# flake8: noqa
from .vq import QuantizedResult, ResidualVectorQuantizer

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# Copyright (c) 2023 Amphion.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
# This source file is copied from https://github.com/facebookresearch/encodec
# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the license found in the
# LICENSE file in the root directory of this source tree.
"""Arithmetic coder."""
import io
import math
import random
import typing as tp
import torch
from ..binary import BitPacker, BitUnpacker
def build_stable_quantized_cdf(
pdf: torch.Tensor,
total_range_bits: int,
roundoff: float = 1e-8,
min_range: int = 2,
check: bool = True,
) -> torch.Tensor:
"""Turn the given PDF into a quantized CDF that splits
[0, 2 ** self.total_range_bits - 1] into chunks of size roughly proportional
to the PDF.
Args:
pdf (torch.Tensor): probability distribution, shape should be `[N]`.
total_range_bits (int): see `ArithmeticCoder`, the typical range we expect
during the coding process is `[0, 2 ** total_range_bits - 1]`.
roundoff (float): will round the pdf up to that level to remove difference coming
from e.g. evaluating the Language Model on different architectures.
min_range (int): minimum range width. Should always be at least 2 for numerical
stability. Use this to avoid pathological behavior is a value
that is expected to be rare actually happens in real life.
check (bool): if True, checks that nothing bad happened, can be deactivated for speed.
"""
pdf = pdf.detach()
if roundoff:
pdf = (pdf / roundoff).floor() * roundoff
# interpolate with uniform distribution to achieve desired minimum probability.
total_range = 2**total_range_bits
cardinality = len(pdf)
alpha = min_range * cardinality / total_range
assert alpha <= 1, "you must reduce min_range"
ranges = (((1 - alpha) * total_range) * pdf).floor().long()
ranges += min_range
quantized_cdf = torch.cumsum(ranges, dim=-1)
if min_range < 2:
raise ValueError("min_range must be at least 2.")
if check:
assert quantized_cdf[-1] <= 2**total_range_bits, quantized_cdf[-1]
if (
(quantized_cdf[1:] - quantized_cdf[:-1]) < min_range
).any() or quantized_cdf[0] < min_range:
raise ValueError("You must increase your total_range_bits.")
return quantized_cdf
class ArithmeticCoder:
"""ArithmeticCoder,
Let us take a distribution `p` over `N` symbols, and assume we have a stream
of random variables `s_t` sampled from `p`. Let us assume that we have a budget
of `B` bits that we can afford to write on device. There are `2**B` possible numbers,
corresponding to the range `[0, 2 ** B - 1]`. We can map each of those number to a single
sequence `(s_t)` by doing the following:
1) Initialize the current range to` [0 ** 2 B - 1]`.
2) For each time step t, split the current range into contiguous chunks,
one for each possible outcome, with size roughly proportional to `p`.
For instance, if `p = [0.75, 0.25]`, and the range is `[0, 3]`, the chunks
would be `{[0, 2], [3, 3]}`.
3) Select the chunk corresponding to `s_t`, and replace the current range with this.
4) When done encoding all the values, just select any value remaining in the range.
You will notice that this procedure can fail: for instance if at any point in time
the range is smaller than `N`, then we can no longer assign a non-empty chunk to each
possible outcome. Intuitively, the more likely a value is, the less the range width
will reduce, and the longer we can go on encoding values. This makes sense: for any efficient
coding scheme, likely outcomes would take less bits, and more of them can be coded
with a fixed budget.
In practice, we do not know `B` ahead of time, but we have a way to inject new bits
when the current range decreases below a given limit (given by `total_range_bits`), without
having to redo all the computations. If we encode mostly likely values, we will seldom
need to inject new bits, but a single rare value can deplete our stock of entropy!
In this explanation, we assumed that the distribution `p` was constant. In fact, the present
code works for any sequence `(p_t)` possibly different for each timestep.
We also assume that `s_t ~ p_t`, but that doesn't need to be true, although the smaller
the KL between the true distribution and `p_t`, the most efficient the coding will be.
Args:
fo (IO[bytes]): file-like object to which the bytes will be written to.
total_range_bits (int): the range `M` described above is `2 ** total_range_bits.
Any time the current range width fall under this limit, new bits will
be injected to rescale the initial range.
"""
def __init__(self, fo: tp.IO[bytes], total_range_bits: int = 24):
assert total_range_bits <= 30
self.total_range_bits = total_range_bits
self.packer = BitPacker(bits=1, fo=fo) # we push single bits at a time.
self.low: int = 0
self.high: int = 0
self.max_bit: int = -1
self._dbg: tp.List[tp.Any] = []
self._dbg2: tp.List[tp.Any] = []
@property
def delta(self) -> int:
"""Return the current range width."""
return self.high - self.low + 1
def _flush_common_prefix(self):
# If self.low and self.high start with the sames bits,
# those won't change anymore as we always just increase the range
# by powers of 2, and we can flush them out to the bit stream.
assert self.high >= self.low, (self.low, self.high)
assert self.high < 2 ** (self.max_bit + 1)
while self.max_bit >= 0:
b1 = self.low >> self.max_bit
b2 = self.high >> self.max_bit
if b1 == b2:
self.low -= b1 << self.max_bit
self.high -= b1 << self.max_bit
assert self.high >= self.low, (self.high, self.low, self.max_bit)
assert self.low >= 0
self.max_bit -= 1
self.packer.push(b1)
else:
break
def push(self, symbol: int, quantized_cdf: torch.Tensor):
"""Push the given symbol on the stream, flushing out bits
if possible.
Args:
symbol (int): symbol to encode with the AC.
quantized_cdf (torch.Tensor): use `build_stable_quantized_cdf`
to build this from your pdf estimate.
"""
while self.delta < 2**self.total_range_bits:
self.low *= 2
self.high = self.high * 2 + 1
self.max_bit += 1
range_low = 0 if symbol == 0 else quantized_cdf[symbol - 1].item()
range_high = quantized_cdf[symbol].item() - 1
effective_low = int(
math.ceil(range_low * (self.delta / (2**self.total_range_bits)))
)
effective_high = int(
math.floor(range_high * (self.delta / (2**self.total_range_bits)))
)
assert self.low <= self.high
self.high = self.low + effective_high
self.low = self.low + effective_low
assert self.low <= self.high, (
effective_low,
effective_high,
range_low,
range_high,
)
self._dbg.append((self.low, self.high))
self._dbg2.append((self.low, self.high))
outs = self._flush_common_prefix()
assert self.low <= self.high
assert self.max_bit >= -1
assert self.max_bit <= 61, self.max_bit
return outs
def flush(self):
"""Flush the remaining information to the stream."""
while self.max_bit >= 0:
b1 = (self.low >> self.max_bit) & 1
self.packer.push(b1)
self.max_bit -= 1
self.packer.flush()
class ArithmeticDecoder:
"""ArithmeticDecoder, see `ArithmeticCoder` for a detailed explanation.
Note that this must be called with **exactly** the same parameters and sequence
of quantized cdf as the arithmetic encoder or the wrong values will be decoded.
If the AC encoder current range is [L, H], with `L` and `H` having the some common
prefix (i.e. the same most significant bits), then this prefix will be flushed to the stream.
For instances, having read 3 bits `b1 b2 b3`, we know that `[L, H]` is contained inside
`[b1 b2 b3 0 ... 0 b1 b3 b3 1 ... 1]`. Now this specific sub-range can only be obtained
for a specific sequence of symbols and a binary-search allows us to decode those symbols.
At some point, the prefix `b1 b2 b3` will no longer be sufficient to decode new symbols,
and we will need to read new bits from the stream and repeat the process.
"""
def __init__(self, fo: tp.IO[bytes], total_range_bits: int = 24):
self.total_range_bits = total_range_bits
self.low: int = 0
self.high: int = 0
self.current: int = 0
self.max_bit: int = -1
self.unpacker = BitUnpacker(bits=1, fo=fo) # we pull single bits at a time.
# Following is for debugging
self._dbg: tp.List[tp.Any] = []
self._dbg2: tp.List[tp.Any] = []
self._last: tp.Any = None
@property
def delta(self) -> int:
return self.high - self.low + 1
def _flush_common_prefix(self):
# Given the current range [L, H], if both have a common prefix,
# we know we can remove it from our representation to avoid handling large numbers.
while self.max_bit >= 0:
b1 = self.low >> self.max_bit
b2 = self.high >> self.max_bit
if b1 == b2:
self.low -= b1 << self.max_bit
self.high -= b1 << self.max_bit
self.current -= b1 << self.max_bit
assert self.high >= self.low
assert self.low >= 0
self.max_bit -= 1
else:
break
def pull(self, quantized_cdf: torch.Tensor) -> tp.Optional[int]:
"""Pull a symbol, reading as many bits from the stream as required.
This returns `None` when the stream has been exhausted.
Args:
quantized_cdf (torch.Tensor): use `build_stable_quantized_cdf`
to build this from your pdf estimate. This must be **exatly**
the same cdf as the one used at encoding time.
"""
while self.delta < 2**self.total_range_bits:
bit = self.unpacker.pull()
if bit is None:
return None
self.low *= 2
self.high = self.high * 2 + 1
self.current = self.current * 2 + bit
self.max_bit += 1
def bin_search(low_idx: int, high_idx: int):
# Binary search is not just for coding interviews :)
if high_idx < low_idx:
raise RuntimeError("Binary search failed")
mid = (low_idx + high_idx) // 2
range_low = quantized_cdf[mid - 1].item() if mid > 0 else 0
range_high = quantized_cdf[mid].item() - 1
effective_low = int(
math.ceil(range_low * (self.delta / (2**self.total_range_bits)))
)
effective_high = int(
math.floor(range_high * (self.delta / (2**self.total_range_bits)))
)
low = effective_low + self.low
high = effective_high + self.low
if self.current >= low:
if self.current <= high:
return (mid, low, high, self.current)
else:
return bin_search(mid + 1, high_idx)
else:
return bin_search(low_idx, mid - 1)
self._last = (self.low, self.high, self.current, self.max_bit)
sym, self.low, self.high, self.current = bin_search(0, len(quantized_cdf) - 1)
self._dbg.append((self.low, self.high, self.current))
self._flush_common_prefix()
self._dbg2.append((self.low, self.high, self.current))
return sym
def test():
torch.manual_seed(1234)
random.seed(1234)
for _ in range(4):
pdfs = []
cardinality = random.randrange(4000)
steps = random.randrange(100, 500)
fo = io.BytesIO()
encoder = ArithmeticCoder(fo)
symbols = []
for step in range(steps):
pdf = torch.softmax(torch.randn(cardinality), dim=0)
pdfs.append(pdf)
q_cdf = build_stable_quantized_cdf(pdf, encoder.total_range_bits)
symbol = torch.multinomial(pdf, 1).item()
symbols.append(symbol)
encoder.push(symbol, q_cdf)
encoder.flush()
fo.seek(0)
decoder = ArithmeticDecoder(fo)
for idx, (pdf, symbol) in enumerate(zip(pdfs, symbols)):
q_cdf = build_stable_quantized_cdf(pdf, encoder.total_range_bits)
decoded_symbol = decoder.pull(q_cdf)
assert decoded_symbol == symbol, idx
assert decoder.pull(torch.zeros(1)) is None
if __name__ == "__main__":
test()

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# Copyright (c) 2023 Amphion.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
# This source file is copied from https://github.com/facebookresearch/encodec
# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the license found in the
# LICENSE file in the root directory of this source tree.
#
# This implementation is inspired from
# https://github.com/lucidrains/vector-quantize-pytorch
# which is released under MIT License. Hereafter, the original license:
# MIT License
#
# Copyright (c) 2020 Phil Wang
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
"""Core vector quantization implementation."""
import typing as tp
from einops import rearrange, repeat
import torch
from torch import nn
import torch.nn.functional as F
from .distrib import broadcast_tensors, rank
def default(val: tp.Any, d: tp.Any) -> tp.Any:
return val if val is not None else d
def ema_inplace(moving_avg, new, decay: float):
moving_avg.data.mul_(decay).add_(new, alpha=(1 - decay))
def laplace_smoothing(x, n_categories: int, epsilon: float = 1e-5):
return (x + epsilon) / (x.sum() + n_categories * epsilon)
def uniform_init(*shape: int):
t = torch.empty(shape)
nn.init.kaiming_uniform_(t)
return t
def sample_vectors(samples, num: int):
num_samples, device = samples.shape[0], samples.device
if num_samples >= num:
indices = torch.randperm(num_samples, device=device)[:num]
else:
indices = torch.randint(0, num_samples, (num,), device=device)
return samples[indices]
def kmeans(samples, num_clusters: int, num_iters: int = 10):
dim, dtype = samples.shape[-1], samples.dtype
means = sample_vectors(samples, num_clusters)
for _ in range(num_iters):
diffs = rearrange(samples, "n d -> n () d") - rearrange(means, "c d -> () c d")
dists = -(diffs**2).sum(dim=-1)
buckets = dists.max(dim=-1).indices
bins = torch.bincount(buckets, minlength=num_clusters)
zero_mask = bins == 0
bins_min_clamped = bins.masked_fill(zero_mask, 1)
new_means = buckets.new_zeros(num_clusters, dim, dtype=dtype)
new_means.scatter_add_(0, repeat(buckets, "n -> n d", d=dim), samples)
new_means = new_means / bins_min_clamped[..., None]
means = torch.where(zero_mask[..., None], means, new_means)
return means, bins
class EuclideanCodebook(nn.Module):
"""Codebook with Euclidean distance.
Args:
dim (int): Dimension.
codebook_size (int): Codebook size.
kmeans_init (bool): Whether to use k-means to initialize the codebooks.
If set to true, run the k-means algorithm on the first training batch and use
the learned centroids as initialization.
kmeans_iters (int): Number of iterations used for k-means algorithm at initialization.
decay (float): Decay for exponential moving average over the codebooks.
epsilon (float): Epsilon value for numerical stability.
threshold_ema_dead_code (int): Threshold for dead code expiration. Replace any codes
that have an exponential moving average cluster size less than the specified threshold with
randomly selected vector from the current batch.
"""
def __init__(
self,
dim: int,
codebook_size: int,
kmeans_init: int = False,
kmeans_iters: int = 10,
decay: float = 0.99,
epsilon: float = 1e-5,
threshold_ema_dead_code: int = 2,
):
super().__init__()
self.decay = decay
init_fn: tp.Union[tp.Callable[..., torch.Tensor], tp.Any] = (
uniform_init if not kmeans_init else torch.zeros
)
embed = init_fn(codebook_size, dim)
self.codebook_size = codebook_size
self.kmeans_iters = kmeans_iters
self.epsilon = epsilon
self.threshold_ema_dead_code = threshold_ema_dead_code
self.register_buffer("inited", torch.Tensor([not kmeans_init]))
self.register_buffer("cluster_size", torch.zeros(codebook_size))
self.register_buffer("embed", embed)
self.register_buffer("embed_avg", embed.clone())
@torch.jit.ignore
def init_embed_(self, data):
if self.inited:
return
embed, cluster_size = kmeans(data, self.codebook_size, self.kmeans_iters)
self.embed.data.copy_(embed)
self.embed_avg.data.copy_(embed.clone())
self.cluster_size.data.copy_(cluster_size)
self.inited.data.copy_(torch.Tensor([True]))
# Make sure all buffers across workers are in sync after initialization
# broadcast_tensors(self.buffers())
def replace_(self, samples, mask):
modified_codebook = torch.where(
mask[..., None], sample_vectors(samples, self.codebook_size), self.embed
)
self.embed.data.copy_(modified_codebook)
def expire_codes_(self, batch_samples):
if self.threshold_ema_dead_code == 0:
return
expired_codes = self.cluster_size < self.threshold_ema_dead_code
if not torch.any(expired_codes):
return
batch_samples = rearrange(batch_samples, "... d -> (...) d")
self.replace_(batch_samples, mask=expired_codes)
# broadcast_tensors(self.buffers())
def preprocess(self, x):
x = rearrange(x, "... d -> (...) d")
return x
def quantize(self, x):
embed = self.embed.t()
dist = -(
x.pow(2).sum(1, keepdim=True)
- 2 * x @ embed
+ embed.pow(2).sum(0, keepdim=True)
)
embed_ind = dist.max(dim=-1).indices
return embed_ind
def postprocess_emb(self, embed_ind, shape):
return embed_ind.view(*shape[:-1])
def dequantize(self, embed_ind):
quantize = F.embedding(embed_ind, self.embed)
return quantize
def encode(self, x):
shape = x.shape
# pre-process
x = self.preprocess(x)
# quantize
embed_ind = self.quantize(x)
# post-process
embed_ind = self.postprocess_emb(embed_ind, shape)
return embed_ind
def decode(self, embed_ind):
quantize = self.dequantize(embed_ind)
return quantize
def forward(self, x):
shape, dtype = x.shape, x.dtype
x = self.preprocess(x)
self.init_embed_(x)
embed_ind = self.quantize(x)
embed_onehot = F.one_hot(embed_ind, self.codebook_size).type(dtype)
embed_ind = self.postprocess_emb(embed_ind, shape)
quantize = self.dequantize(embed_ind)
if self.training:
# We do the expiry of code at that point as buffers are in sync
# and all the workers will take the same decision.
self.expire_codes_(x)
ema_inplace(self.cluster_size, embed_onehot.sum(0), self.decay)
embed_sum = x.t() @ embed_onehot
ema_inplace(self.embed_avg, embed_sum.t(), self.decay)
cluster_size = (
laplace_smoothing(self.cluster_size, self.codebook_size, self.epsilon)
* self.cluster_size.sum()
)
embed_normalized = self.embed_avg / cluster_size.unsqueeze(1)
self.embed.data.copy_(embed_normalized)
return quantize, embed_ind
class VectorQuantization(nn.Module):
"""Vector quantization implementation.
Currently supports only euclidean distance.
Args:
dim (int): Dimension
codebook_size (int): Codebook size
codebook_dim (int): Codebook dimension. If not defined, uses the specified dimension in dim.
decay (float): Decay for exponential moving average over the codebooks.
epsilon (float): Epsilon value for numerical stability.
kmeans_init (bool): Whether to use kmeans to initialize the codebooks.
kmeans_iters (int): Number of iterations used for kmeans initialization.
threshold_ema_dead_code (int): Threshold for dead code expiration. Replace any codes
that have an exponential moving average cluster size less than the specified threshold with
randomly selected vector from the current batch.
commitment_weight (float): Weight for commitment loss.
"""
def __init__(
self,
dim: int,
codebook_size: int,
codebook_dim: tp.Optional[int] = None,
decay: float = 0.99,
epsilon: float = 1e-5,
kmeans_init: bool = True,
kmeans_iters: int = 50,
threshold_ema_dead_code: int = 2,
commitment_weight: float = 1.0,
):
super().__init__()
_codebook_dim: int = default(codebook_dim, dim)
requires_projection = _codebook_dim != dim
self.project_in = (
nn.Linear(dim, _codebook_dim) if requires_projection else nn.Identity()
)
self.project_out = (
nn.Linear(_codebook_dim, dim) if requires_projection else nn.Identity()
)
self.epsilon = epsilon
self.commitment_weight = commitment_weight
self._codebook = EuclideanCodebook(
dim=_codebook_dim,
codebook_size=codebook_size,
kmeans_init=kmeans_init,
kmeans_iters=kmeans_iters,
decay=decay,
epsilon=epsilon,
threshold_ema_dead_code=threshold_ema_dead_code,
)
self.codebook_size = codebook_size
@property
def codebook(self):
return self._codebook.embed
def encode(self, x):
x = rearrange(x, "b d n -> b n d")
x = self.project_in(x)
embed_in = self._codebook.encode(x)
return embed_in
def decode(self, embed_ind):
quantize = self._codebook.decode(embed_ind)
quantize = self.project_out(quantize)
quantize = rearrange(quantize, "b n d -> b d n")
return quantize
def forward(self, x):
device = x.device
x = rearrange(x, "b d n -> b n d")
x = self.project_in(x)
quantize, embed_ind = self._codebook(x)
if self.training:
quantize = x + (quantize - x).detach()
loss = torch.tensor([0.0], device=device, requires_grad=self.training)
if self.training:
if self.commitment_weight > 0:
commit_loss = F.mse_loss(quantize.detach(), x)
loss = loss + commit_loss * self.commitment_weight
quantize = self.project_out(quantize)
quantize = rearrange(quantize, "b n d -> b d n")
return quantize, embed_ind, loss
class ResidualVectorQuantization(nn.Module):
"""Residual vector quantization implementation.
Follows Algorithm 1. in https://arxiv.org/pdf/2107.03312.pdf
"""
def __init__(self, *, num_quantizers, **kwargs):
super().__init__()
self.layers = nn.ModuleList(
[VectorQuantization(**kwargs) for _ in range(num_quantizers)]
)
def forward(
self, x, n_q: tp.Optional[int] = None, layers: tp.Optional[list] = None
):
quantized_out = 0.0
residual = x
all_losses = []
all_indices = []
out_quantized = []
n_q = n_q or len(self.layers)
for i, layer in enumerate(self.layers[:n_q]):
quantized, indices, loss = layer(residual)
residual = residual - quantized
quantized_out = quantized_out + quantized
all_indices.append(indices)
all_losses.append(loss)
if layers and i in layers:
out_quantized.append(quantized)
out_losses, out_indices = map(torch.stack, (all_losses, all_indices))
return quantized_out, out_indices, out_losses, out_quantized
def encode(
self, x: torch.Tensor, n_q: tp.Optional[int] = None, st: tp.Optional[int] = None
) -> torch.Tensor:
residual = x
all_indices = []
n_q = n_q or len(self.layers)
st = st or 0
for layer in self.layers[st:n_q]:
indices = layer.encode(residual)
quantized = layer.decode(indices)
residual = residual - quantized
all_indices.append(indices)
out_indices = torch.stack(all_indices)
return out_indices
def decode(self, q_indices: torch.Tensor, st: int = 0) -> torch.Tensor:
quantized_out = torch.tensor(0.0, device=q_indices.device)
for i, indices in enumerate(q_indices):
layer = self.layers[st + i]
quantized = layer.decode(indices)
quantized_out = quantized_out + quantized
return quantized_out

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# Copyright (c) 2023 Amphion.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
# This source file is copied from https://github.com/facebookresearch/encodec
# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the license found in the
# LICENSE file in the root directory of this source tree.
"""Torch distributed utilities."""
import typing as tp
import torch
def rank():
if torch.distributed.is_initialized():
return torch.distributed.get_rank()
else:
return 0
def world_size():
if torch.distributed.is_initialized():
return torch.distributed.get_world_size()
else:
return 1
def is_distributed():
return world_size() > 1
def all_reduce(tensor: torch.Tensor, op=torch.distributed.ReduceOp.SUM):
if is_distributed():
return torch.distributed.all_reduce(tensor, op)
def _is_complex_or_float(tensor):
return torch.is_floating_point(tensor) or torch.is_complex(tensor)
def _check_number_of_params(params: tp.List[torch.Tensor]):
# utility function to check that the number of params in all workers is the same,
# and thus avoid a deadlock with distributed all reduce.
if not is_distributed() or not params:
return
# print('params[0].device ', params[0].device)
tensor = torch.tensor([len(params)], device=params[0].device, dtype=torch.long)
all_reduce(tensor)
if tensor.item() != len(params) * world_size():
# If not all the workers have the same number, for at least one of them,
# this inequality will be verified.
raise RuntimeError(
f"Mismatch in number of params: ours is {len(params)}, "
"at least one worker has a different one."
)
def broadcast_tensors(tensors: tp.Iterable[torch.Tensor], src: int = 0):
"""Broadcast the tensors from the given parameters to all workers.
This can be used to ensure that all workers have the same model to start with.
"""
if not is_distributed():
return
tensors = [tensor for tensor in tensors if _is_complex_or_float(tensor)]
_check_number_of_params(tensors)
handles = []
for tensor in tensors:
# src = int(rank()) # added code
handle = torch.distributed.broadcast(tensor.data, src=src, async_op=True)
handles.append(handle)
for handle in handles:
handle.wait()
def sync_buffer(buffers, average=True):
"""
Sync grad for buffers. If average is False, broadcast instead of averaging.
"""
if not is_distributed():
return
handles = []
for buffer in buffers:
if torch.is_floating_point(buffer.data):
if average:
handle = torch.distributed.all_reduce(
buffer.data, op=torch.distributed.ReduceOp.SUM, async_op=True
)
else:
handle = torch.distributed.broadcast(buffer.data, src=0, async_op=True)
handles.append((buffer, handle))
for buffer, handle in handles:
handle.wait()
if average:
buffer.data /= world_size
def sync_grad(params):
"""
Simpler alternative to DistributedDataParallel, that doesn't rely
on any black magic. For simple models it can also be as fast.
Just call this on your model parameters after the call to backward!
"""
if not is_distributed():
return
handles = []
for p in params:
if p.grad is not None:
handle = torch.distributed.all_reduce(
p.grad.data, op=torch.distributed.ReduceOp.SUM, async_op=True
)
handles.append((p, handle))
for p, handle in handles:
handle.wait()
p.grad.data /= world_size()
def average_metrics(metrics: tp.Dict[str, float], count=1.0):
"""Average a dictionary of metrics across all workers, using the optional
`count` as unormalized weight.
"""
if not is_distributed():
return metrics
keys, values = zip(*metrics.items())
device = "cuda" if torch.cuda.is_available() else "cpu"
tensor = torch.tensor(list(values) + [1], device=device, dtype=torch.float32)
tensor *= count
all_reduce(tensor)
averaged = (tensor[:-1] / tensor[-1]).cpu().tolist()
return dict(zip(keys, averaged))

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# Copyright (c) 2023 Amphion.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
# This source file is copied from https://github.com/facebookresearch/encodec
# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the license found in the
# LICENSE file in the root directory of this source tree.
"""Residual vector quantizer implementation."""
from dataclasses import dataclass, field
import math
import typing as tp
import torch
from torch import nn
from .core_vq import ResidualVectorQuantization
@dataclass
class QuantizedResult:
quantized: torch.Tensor
codes: torch.Tensor
bandwidth: torch.Tensor # bandwidth in kb/s used, per batch item.
penalty: tp.Optional[torch.Tensor] = None
metrics: dict = field(default_factory=dict)
class ResidualVectorQuantizer(nn.Module):
"""Residual Vector Quantizer.
Args:
dimension (int): Dimension of the codebooks.
n_q (int): Number of residual vector quantizers used.
bins (int): Codebook size.
decay (float): Decay for exponential moving average over the codebooks.
kmeans_init (bool): Whether to use kmeans to initialize the codebooks.
kmeans_iters (int): Number of iterations used for kmeans initialization.
threshold_ema_dead_code (int): Threshold for dead code expiration. Replace any codes
that have an exponential moving average cluster size less than the specified threshold with
randomly selected vector from the current batch.
"""
def __init__(
self,
dimension: int = 256,
n_q: int = 8,
bins: int = 1024,
decay: float = 0.99,
kmeans_init: bool = True,
kmeans_iters: int = 50,
threshold_ema_dead_code: int = 2,
):
super().__init__()
self.n_q = n_q
self.dimension = dimension
self.bins = bins
self.decay = decay
self.kmeans_init = kmeans_init
self.kmeans_iters = kmeans_iters
self.threshold_ema_dead_code = threshold_ema_dead_code
self.vq = ResidualVectorQuantization(
dim=self.dimension,
codebook_size=self.bins,
num_quantizers=self.n_q,
decay=self.decay,
kmeans_init=self.kmeans_init,
kmeans_iters=self.kmeans_iters,
threshold_ema_dead_code=self.threshold_ema_dead_code,
)
def forward(
self,
x: torch.Tensor,
n_q: tp.Optional[int] = None,
layers: tp.Optional[list] = None,
) -> QuantizedResult:
"""Residual vector quantization on the given input tensor.
Args:
x (torch.Tensor): Input tensor.
n_q (int): Number of quantizer used to quantize. Default: All quantizers.
layers (list): Layer that need to return quantized. Defalt: None.
Returns:
QuantizedResult:
The quantized (or approximately quantized) representation with
the associated numbert quantizers and layer quantized required to return.
"""
n_q = n_q if n_q else self.n_q
if layers and max(layers) >= n_q:
raise ValueError(
f"Last layer index in layers: A {max(layers)}. Number of quantizers in RVQ: B {self.n_q}. A must less than B."
)
quantized, codes, commit_loss, quantized_list = self.vq(
x, n_q=n_q, layers=layers
)
return quantized, codes, torch.mean(commit_loss), quantized_list
def encode(
self, x: torch.Tensor, n_q: tp.Optional[int] = None, st: tp.Optional[int] = None
) -> torch.Tensor:
"""Encode a given input tensor with the specified sample rate at the given bandwidth.
The RVQ encode method sets the appropriate number of quantizer to use
and returns indices for each quantizer.
Args:
x (torch.Tensor): Input tensor.
n_q (int): Number of quantizer used to quantize. Default: All quantizers.
st (int): Start to encode input from which layers. Default: 0.
"""
n_q = n_q if n_q else self.n_q
st = st or 0
codes = self.vq.encode(x, n_q=n_q, st=st)
return codes
def decode(self, codes: torch.Tensor, st: int = 0) -> torch.Tensor:
"""Decode the given codes to the quantized representation.
Args:
codes (torch.Tensor): Input indices for each quantizer.
st (int): Start to decode input codes from which layers. Default: 0.
"""
quantized = self.vq.decode(codes, st=st)
return quantized