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Publish pinned visual components with exact source payloads and native numerical validation
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import torch
from typing import List, Tuple
from torch.nn import functional as F
from torch import distributed as tdist, nn as nn
from native.utils import dist
def get_entropy_loss(latent_embed, codebook_embed, inv_entropy_tau):
E_dist = latent_embed.square().sum(dim=1, keepdim=True) + codebook_embed.square().sum(dim=1, keepdim=False)
E_dist.addmm_(latent_embed, codebook_embed.T, alpha=-2, beta=1) # E_dist: (N, vocab_size)
logits = -E_dist.float().mul_(inv_entropy_tau)
# calc per_sample_entropy
prob, log_prob = logits.softmax(dim=-1), logits.log_softmax(dim=-1) # both are (N, vocab_size)
per_sample_entropy = torch.mean((-prob * log_prob).sum(dim=-1))
# calc codebook_entropy
avg_prob = prob.mean(dim=0) # (vocab_size,)
log_avg_prob = torch.log(avg_prob + 1e-7)
codebook_entropy = (-avg_prob * log_avg_prob).sum()
# calc entropy_loss
entropy_loss = per_sample_entropy - codebook_entropy
return entropy_loss
class NormalizedEmbedding(nn.Embedding):
def __init__(self, num_embeddings: int, embedding_dim: int):
super().__init__(num_embeddings=num_embeddings, embedding_dim=embedding_dim)
# self.norm_scale = nn.Parameter(torch.tensor(0.0, dtype=torch.float32))
def forward(self, idx):
return F.embedding(
idx, F.normalize(self.weight, dim=1), self.padding_idx, self.max_norm,
self.norm_type, self.scale_grad_by_freq, self.sparse
)
def get_norm_weight(self):
return F.normalize(self.weight, dim=1)
class ResConv(nn.Conv2d):
def __init__(self, embed_dim, quant_resi):
ks = 3 if quant_resi < 0 else 1
super().__init__(in_channels=embed_dim, out_channels=embed_dim, kernel_size=ks, stride=1, padding=ks // 2)
self.resi_ratio = abs(quant_resi)
def forward(self, h_BChw):
return h_BChw.mul(1 - self.resi_ratio) + super().forward(h_BChw).mul_(self.resi_ratio)
class VectorQuantizer(nn.Module):
def __init__(
self,
vocab_size: int,
vocab_width: int,
beta: float = 0.25,
use_entropy_loss=False,
entropy_temp=0.01,
):
super().__init__()
self.beta = beta
self.vocab_size = vocab_size
self.vocab_width = vocab_width
self.vocab_usage_record_times: int = 0
self.register_buffer('vocab_usage', torch.zeros(self.vocab_size))
self.codebook = NormalizedEmbedding(self.vocab_size, self.vocab_width)
self.use_entropy_loss = use_entropy_loss
self.inv_entropy_tau = 1 / entropy_temp
def init_vocab(self, eini: float):
if eini > 0:
nn.init.trunc_normal_(self.codebook.weight.data, std=eini)
elif eini < 0:
base = self.vocab_width ** -0.5
base /= 36
self.codebook.weight.data.uniform_(-abs(eini) * base, abs(eini) * base)
def extra_repr(self) -> str:
return f'beta={self.beta:g}'
def forward(self, features):
B, L, C = features.shape
features = features.reshape(-1, C)
features = F.normalize(features, dim=-1).float()
codebook_embed = self.codebook.get_norm_weight()
indices = torch.argmax(features.detach() @ codebook_embed.T, dim=1)
entropy_loss = get_entropy_loss(features, codebook_embed, self.inv_entropy_tau) if self.use_entropy_loss else 0
features_hat = self.codebook(indices)
# calc loss
vq_loss = F.mse_loss(features_hat.detach(), features).mul_(self.beta) + F.mse_loss(features_hat,
features.detach())
features_hat = (features_hat.detach() - features.detach()).add_(features)
# update vocab_usage
prob_per_class_is_chosen = indices.bincount(minlength=self.vocab_size).float()
handler = tdist.all_reduce(prob_per_class_is_chosen, async_op=True) if (
self.training and dist.initialized()) else None
if handler is not None:
handler.wait()
prob_per_class_is_chosen /= prob_per_class_is_chosen.sum()
vocab_usage = (prob_per_class_is_chosen > 0.01 / self.vocab_size).float().mean().mul_(100)
if self.vocab_usage_record_times == 0:
self.vocab_usage.copy_(prob_per_class_is_chosen)
elif self.vocab_usage_record_times < 100:
self.vocab_usage.mul_(0.9).add_(prob_per_class_is_chosen, alpha=0.1)
else:
self.vocab_usage.mul_(0.99).add_(prob_per_class_is_chosen, alpha=0.01)
self.vocab_usage_record_times += 1
return features_hat.view(B, L, C), vq_loss, entropy_loss, vocab_usage
def f_to_idx(self, features):
B, L, C = features.shape
features = features.reshape(-1, C)
features = F.normalize(features, dim=-1).float()
codebook_embed = self.codebook.get_norm_weight().float()
indices = torch.argmax(features.detach() @ codebook_embed.T, dim=1)
return indices.view(B, L)
class VectorQuantizerM(nn.Module):
def __init__(
self,
vocab_size,
vocab_width,
beta=0.25,
use_entropy_loss=False,
entropy_temp=0.01,
num_codebooks=16
):
super().__init__()
self.num_codebooks = num_codebooks
self.codebooks = nn.ModuleList()
for _ in range(num_codebooks):
codebook = VectorQuantizer(
vocab_size=vocab_size // num_codebooks,
vocab_width=vocab_width // num_codebooks,
beta=beta,
use_entropy_loss=use_entropy_loss,
entropy_temp=entropy_temp,
)
self.codebooks.append(codebook)
def init_vocab(self, eini: float):
for codebook in self.codebooks:
codebook.init_vocab(eini)
def f_to_idx(self, features):
indices = []
chunk_size = features.shape[-1] // self.num_codebooks
splited_features = features.split(chunk_size, dim=-1)
for i, codebook in enumerate(self.codebooks):
indices.append(codebook.f_to_idx(splited_features[i]))
indices = torch.stack(indices, dim=1)
return indices
def idx_to_f(self, indices):
assert indices.shape[1] == self.num_codebooks
latent_features = []
for i, codebook in enumerate(self.codebooks):
sub_indices = indices[:, i].flatten(start_dim=1)
latent_feature = codebook.codebook(sub_indices)
latent_features.append(latent_feature)
latent_features = torch.cat(latent_features, dim=-1)
return latent_features
def forward(self, features):
latent_features = []
global_vq_loss = 0.
global_entropy_loss = 0.
global_vocab_usage = 0.
chunk_size = features.shape[-1] // self.num_codebooks
splited_features = features.split(chunk_size, dim=-1)
for i, codebook in enumerate(self.codebooks):
latent_feature, vq_loss, entropy_loss, vocab_usage = codebook(splited_features[i])
latent_features.append(latent_feature)
global_vq_loss += vq_loss
global_entropy_loss += entropy_loss
global_vocab_usage += vocab_usage
latent_features = torch.cat(latent_features, dim=-1)
global_entropy_loss /= self.num_codebooks
global_vq_loss /= self.num_codebooks
global_vocab_usage /= self.num_codebooks
return latent_features, global_vq_loss, global_entropy_loss, global_vocab_usage