InvokeAI/ldm/modules/encoders/modules.py

550 lines
16 KiB
Python

import torch
import torch.nn as nn
from functools import partial
import clip
from einops import rearrange, repeat
from transformers import CLIPTokenizer, CLIPTextModel
import kornia
from ldm.dream.devices import choose_torch_device
from ldm.modules.x_transformer import (
Encoder,
TransformerWrapper,
) # TODO: can we directly rely on lucidrains code and simply add this as a reuirement? --> test
def _expand_mask(mask, dtype, tgt_len=None):
"""
Expands attention_mask from `[bsz, seq_len]` to `[bsz, 1, tgt_seq_len, src_seq_len]`.
"""
bsz, src_len = mask.size()
tgt_len = tgt_len if tgt_len is not None else src_len
expanded_mask = (
mask[:, None, None, :].expand(bsz, 1, tgt_len, src_len).to(dtype)
)
inverted_mask = 1.0 - expanded_mask
return inverted_mask.masked_fill(
inverted_mask.to(torch.bool), torch.finfo(dtype).min
)
def _build_causal_attention_mask(bsz, seq_len, dtype):
# lazily create causal attention mask, with full attention between the vision tokens
# pytorch uses additive attention mask; fill with -inf
mask = torch.empty(bsz, seq_len, seq_len, dtype=dtype)
mask.fill_(torch.tensor(torch.finfo(dtype).min))
mask.triu_(1) # zero out the lower diagonal
mask = mask.unsqueeze(1) # expand mask
return mask
class AbstractEncoder(nn.Module):
def __init__(self):
super().__init__()
def encode(self, *args, **kwargs):
raise NotImplementedError
class ClassEmbedder(nn.Module):
def __init__(self, embed_dim, n_classes=1000, key='class'):
super().__init__()
self.key = key
self.embedding = nn.Embedding(n_classes, embed_dim)
def forward(self, batch, key=None):
if key is None:
key = self.key
# this is for use in crossattn
c = batch[key][:, None]
c = self.embedding(c)
return c
class TransformerEmbedder(AbstractEncoder):
"""Some transformer encoder layers"""
def __init__(
self,
n_embed,
n_layer,
vocab_size,
max_seq_len=77,
device=choose_torch_device(),
):
super().__init__()
self.device = device
self.transformer = TransformerWrapper(
num_tokens=vocab_size,
max_seq_len=max_seq_len,
attn_layers=Encoder(dim=n_embed, depth=n_layer),
)
def forward(self, tokens):
tokens = tokens.to(self.device) # meh
z = self.transformer(tokens, return_embeddings=True)
return z
def encode(self, x):
return self(x)
class BERTTokenizer(AbstractEncoder):
"""Uses a pretrained BERT tokenizer by huggingface. Vocab size: 30522 (?)"""
def __init__(
self, device=choose_torch_device(), vq_interface=True, max_length=77
):
super().__init__()
from transformers import (
BertTokenizerFast,
) # TODO: add to reuquirements
# Modified to allow to run on non-internet connected compute nodes.
# Model needs to be loaded into cache from an internet-connected machine
# by running:
# from transformers import BertTokenizerFast
# BertTokenizerFast.from_pretrained("bert-base-uncased")
try:
self.tokenizer = BertTokenizerFast.from_pretrained(
'bert-base-uncased', local_files_only=True
)
except OSError:
raise SystemExit(
"* Couldn't load Bert tokenizer files. Try running scripts/preload_models.py from an internet-conected machine."
)
self.device = device
self.vq_interface = vq_interface
self.max_length = max_length
def forward(self, text):
batch_encoding = self.tokenizer(
text,
truncation=True,
max_length=self.max_length,
return_length=True,
return_overflowing_tokens=False,
padding='max_length',
return_tensors='pt',
)
tokens = batch_encoding['input_ids'].to(self.device)
return tokens
@torch.no_grad()
def encode(self, text):
tokens = self(text)
if not self.vq_interface:
return tokens
return None, None, [None, None, tokens]
def decode(self, text):
return text
class BERTEmbedder(AbstractEncoder):
"""Uses the BERT tokenizr model and add some transformer encoder layers"""
def __init__(
self,
n_embed,
n_layer,
vocab_size=30522,
max_seq_len=77,
device=choose_torch_device(),
use_tokenizer=True,
embedding_dropout=0.0,
):
super().__init__()
self.use_tknz_fn = use_tokenizer
if self.use_tknz_fn:
self.tknz_fn = BERTTokenizer(
vq_interface=False, max_length=max_seq_len
)
self.device = device
self.transformer = TransformerWrapper(
num_tokens=vocab_size,
max_seq_len=max_seq_len,
attn_layers=Encoder(dim=n_embed, depth=n_layer),
emb_dropout=embedding_dropout,
)
def forward(self, text, embedding_manager=None):
if self.use_tknz_fn:
tokens = self.tknz_fn(text) # .to(self.device)
else:
tokens = text
z = self.transformer(
tokens, return_embeddings=True, embedding_manager=embedding_manager
)
return z
def encode(self, text, **kwargs):
# output of length 77
return self(text, **kwargs)
class SpatialRescaler(nn.Module):
def __init__(
self,
n_stages=1,
method='bilinear',
multiplier=0.5,
in_channels=3,
out_channels=None,
bias=False,
):
super().__init__()
self.n_stages = n_stages
assert self.n_stages >= 0
assert method in [
'nearest',
'linear',
'bilinear',
'trilinear',
'bicubic',
'area',
]
self.multiplier = multiplier
self.interpolator = partial(
torch.nn.functional.interpolate, mode=method
)
self.remap_output = out_channels is not None
if self.remap_output:
print(
f'Spatial Rescaler mapping from {in_channels} to {out_channels} channels after resizing.'
)
self.channel_mapper = nn.Conv2d(
in_channels, out_channels, 1, bias=bias
)
def forward(self, x):
for stage in range(self.n_stages):
x = self.interpolator(x, scale_factor=self.multiplier)
if self.remap_output:
x = self.channel_mapper(x)
return x
def encode(self, x):
return self(x)
class FrozenCLIPEmbedder(AbstractEncoder):
"""Uses the CLIP transformer encoder for text (from Hugging Face)"""
def __init__(
self,
version='openai/clip-vit-large-patch14',
device=choose_torch_device(),
max_length=77,
):
super().__init__()
self.tokenizer = CLIPTokenizer.from_pretrained(
version, local_files_only=True
)
self.transformer = CLIPTextModel.from_pretrained(
version, local_files_only=True
)
self.device = device
self.max_length = max_length
self.freeze()
def embedding_forward(
self,
input_ids=None,
position_ids=None,
inputs_embeds=None,
embedding_manager=None,
) -> torch.Tensor:
seq_length = (
input_ids.shape[-1]
if input_ids is not None
else inputs_embeds.shape[-2]
)
if position_ids is None:
position_ids = self.position_ids[:, :seq_length]
if inputs_embeds is None:
inputs_embeds = self.token_embedding(input_ids)
if embedding_manager is not None:
inputs_embeds = embedding_manager(input_ids, inputs_embeds)
position_embeddings = self.position_embedding(position_ids)
embeddings = inputs_embeds + position_embeddings
return embeddings
self.transformer.text_model.embeddings.forward = (
embedding_forward.__get__(self.transformer.text_model.embeddings)
)
def encoder_forward(
self,
inputs_embeds,
attention_mask=None,
causal_attention_mask=None,
output_attentions=None,
output_hidden_states=None,
return_dict=None,
):
output_attentions = (
output_attentions
if output_attentions is not None
else self.config.output_attentions
)
output_hidden_states = (
output_hidden_states
if output_hidden_states is not None
else self.config.output_hidden_states
)
return_dict = (
return_dict
if return_dict is not None
else self.config.use_return_dict
)
encoder_states = () if output_hidden_states else None
all_attentions = () if output_attentions else None
hidden_states = inputs_embeds
for idx, encoder_layer in enumerate(self.layers):
if output_hidden_states:
encoder_states = encoder_states + (hidden_states,)
layer_outputs = encoder_layer(
hidden_states,
attention_mask,
causal_attention_mask,
output_attentions=output_attentions,
)
hidden_states = layer_outputs[0]
if output_attentions:
all_attentions = all_attentions + (layer_outputs[1],)
if output_hidden_states:
encoder_states = encoder_states + (hidden_states,)
return hidden_states
self.transformer.text_model.encoder.forward = encoder_forward.__get__(
self.transformer.text_model.encoder
)
def text_encoder_forward(
self,
input_ids=None,
attention_mask=None,
position_ids=None,
output_attentions=None,
output_hidden_states=None,
return_dict=None,
embedding_manager=None,
):
output_attentions = (
output_attentions
if output_attentions is not None
else self.config.output_attentions
)
output_hidden_states = (
output_hidden_states
if output_hidden_states is not None
else self.config.output_hidden_states
)
return_dict = (
return_dict
if return_dict is not None
else self.config.use_return_dict
)
if input_ids is None:
raise ValueError('You have to specify either input_ids')
input_shape = input_ids.size()
input_ids = input_ids.view(-1, input_shape[-1])
hidden_states = self.embeddings(
input_ids=input_ids,
position_ids=position_ids,
embedding_manager=embedding_manager,
)
bsz, seq_len = input_shape
# CLIP's text model uses causal mask, prepare it here.
# https://github.com/openai/CLIP/blob/cfcffb90e69f37bf2ff1e988237a0fbe41f33c04/clip/model.py#L324
causal_attention_mask = _build_causal_attention_mask(
bsz, seq_len, hidden_states.dtype
).to(hidden_states.device)
# expand attention_mask
if attention_mask is not None:
# [bsz, seq_len] -> [bsz, 1, tgt_seq_len, src_seq_len]
attention_mask = _expand_mask(
attention_mask, hidden_states.dtype
)
last_hidden_state = self.encoder(
inputs_embeds=hidden_states,
attention_mask=attention_mask,
causal_attention_mask=causal_attention_mask,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
last_hidden_state = self.final_layer_norm(last_hidden_state)
return last_hidden_state
self.transformer.text_model.forward = text_encoder_forward.__get__(
self.transformer.text_model
)
def transformer_forward(
self,
input_ids=None,
attention_mask=None,
position_ids=None,
output_attentions=None,
output_hidden_states=None,
return_dict=None,
embedding_manager=None,
):
return self.text_model(
input_ids=input_ids,
attention_mask=attention_mask,
position_ids=position_ids,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
embedding_manager=embedding_manager,
)
self.transformer.forward = transformer_forward.__get__(
self.transformer
)
def freeze(self):
self.transformer = self.transformer.eval()
for param in self.parameters():
param.requires_grad = False
def forward(self, text, **kwargs):
batch_encoding = self.tokenizer(
text,
truncation=True,
max_length=self.max_length,
return_length=True,
return_overflowing_tokens=False,
padding='max_length',
return_tensors='pt',
)
tokens = batch_encoding['input_ids'].to(self.device)
z = self.transformer(input_ids=tokens, **kwargs)
return z
def encode(self, text, **kwargs):
return self(text, **kwargs)
class FrozenCLIPTextEmbedder(nn.Module):
"""
Uses the CLIP transformer encoder for text.
"""
def __init__(
self,
version='ViT-L/14',
device=choose_torch_device(),
max_length=77,
n_repeat=1,
normalize=True,
):
super().__init__()
self.model, _ = clip.load(version, jit=False, device=device)
self.device = device
self.max_length = max_length
self.n_repeat = n_repeat
self.normalize = normalize
def freeze(self):
self.model = self.model.eval()
for param in self.parameters():
param.requires_grad = False
def forward(self, text):
tokens = clip.tokenize(text).to(self.device)
z = self.model.encode_text(tokens)
if self.normalize:
z = z / torch.linalg.norm(z, dim=1, keepdim=True)
return z
def encode(self, text):
z = self(text)
if z.ndim == 2:
z = z[:, None, :]
z = repeat(z, 'b 1 d -> b k d', k=self.n_repeat)
return z
class FrozenClipImageEmbedder(nn.Module):
"""
Uses the CLIP image encoder.
"""
def __init__(
self,
model,
jit=False,
device=choose_torch_device(),
antialias=False,
):
super().__init__()
self.model, _ = clip.load(name=model, device=device, jit=jit)
self.antialias = antialias
self.register_buffer(
'mean',
torch.Tensor([0.48145466, 0.4578275, 0.40821073]),
persistent=False,
)
self.register_buffer(
'std',
torch.Tensor([0.26862954, 0.26130258, 0.27577711]),
persistent=False,
)
def preprocess(self, x):
# normalize to [0,1]
x = kornia.geometry.resize(
x,
(224, 224),
interpolation='bicubic',
align_corners=True,
antialias=self.antialias,
)
x = (x + 1.0) / 2.0
# renormalize according to clip
x = kornia.enhance.normalize(x, self.mean, self.std)
return x
def forward(self, x):
# x is assumed to be in range [-1,1]
return self.model.encode_image(self.preprocess(x))
if __name__ == '__main__':
from ldm.util import count_params
model = FrozenCLIPEmbedder()
count_params(model, verbose=True)