import os, math
import torch
import torch.nn.functional as F
import pytorch_lightning as pl
from main import instantiate_from_config
from taming.modules.util import SOSProvider
def disabled_train(self, mode=True):
"""Overwrite model.train with this function to make sure train/eval mode
does not change anymore."""
return self
class Net2NetTransformer(pl.LightningModule):
def __init__(self,
transformer_config,
first_stage_config,
cond_stage_config,
permuter_config=None,
ckpt_path=None,
ignore_keys=[],
first_stage_key="image",
cond_stage_key="depth",
downsample_cond_size=-1,
pkeep=1.0,
sos_token=0,
unconditional=False,
):
super().__init__()
self.be_unconditional = unconditional
self.sos_token = sos_token
self.first_stage_key = first_stage_key
self.cond_stage_key = cond_stage_key
self.init_first_stage_from_ckpt(first_stage_config)
self.init_cond_stage_from_ckpt(cond_stage_config)
if permuter_config is None:
permuter_config = {"target": "taming.modules.transformer.permuter.Identity"}
self.permuter = instantiate_from_config(config=permuter_config)
self.transformer = instantiate_from_config(config=transformer_config)
if ckpt_path is not None:
self.init_from_ckpt(ckpt_path, ignore_keys=ignore_keys)
self.downsample_cond_size = downsample_cond_size
self.pkeep = pkeep
def init_from_ckpt(self, path, ignore_keys=list()):
sd = torch.load(path, map_location="cpu")["state_dict"]
for k in sd.keys():
for ik in ignore_keys:
if k.startswith(ik):
self.print("Deleting key {} from state_dict.".format(k))
del sd[k]
self.load_state_dict(sd, strict=False)
print(f"Restored from {path}")
def init_first_stage_from_ckpt(self, config):
model = instantiate_from_config(config)
model = model.eval()
model.train = disabled_train
self.first_stage_model = model
def init_cond_stage_from_ckpt(self, config):
if config == "__is_first_stage__":
print("Using first stage also as cond stage.")
self.cond_stage_model = self.first_stage_model
elif config == "__is_unconditional__" or self.be_unconditional:
print(f"Using no cond stage. Assuming the training is intended to be unconditional. "
f"Prepending {self.sos_token} as a sos token.")
self.be_unconditional = True
self.cond_stage_key = self.first_stage_key
self.cond_stage_model = SOSProvider(self.sos_token)
else:
model = instantiate_from_config(config)
model = model.eval()
model.train = disabled_train
self.cond_stage_model = model
def forward(self, x, c):
# one step to produce the logits
_, z_indices = self.encode_to_z(x)
_, c_indices = self.encode_to_c(c)
if self.training and self.pkeep < 1.0:
mask = torch.bernoulli(self.pkeep*torch.ones(z_indices.shape,
device=z_indices.device))
mask = mask.round().to(dtype=torch.int64)
r_indices = torch.randint_like(z_indices, self.transformer.config.vocab_size)
a_indices = mask*z_indices+(1-mask)*r_indices
else:
a_indices = z_indices
cz_indices = torch.cat((c_indices, a_indices), dim=1)
# target includes all sequence elements (no need to handle first one
# differently because we are conditioning)
target = z_indices
# make the prediction
logits, _ = self.transformer(cz_indices[:, :-1])
# cut off conditioning outputs - output i corresponds to p(z_i | z_{<i}, c)
logits = logits[:, c_indices.shape[1]-1:]
return logits, target
def top_k_logits(self, logits, k):
v, ix = torch.topk(logits, k)
out = logits.clone()
out[out < v[..., [-1]]] = -float('Inf')
return out
@torch.no_grad()
def sample(self, x, c, steps, temperature=1.0, sample=False, top_k=None,
callback=lambda k: None):
x = torch.cat((c,x),dim=1)
block_size = self.transformer.get_block_size()
assert not self.transformer.training
if self.pkeep <= 0.0:
# one pass suffices since input is pure noise anyway
assert len(x.shape)==2
noise_shape = (x.shape[0], steps-1)
#noise = torch.randint(self.transformer.config.vocab_size, noise_shape).to(x)
noise = c.clone()[:,x.shape[1]-c.shape[1]:-1]
x = torch.cat((x,noise),dim=1)
logits, _ = self.transformer(x)
# take all logits for now and scale by temp
logits = logits / temperature
# optionally crop probabilities to only the top k options
if top_k is not None:
logits = self.top_k_logits(logits, top_k)
# apply softmax to convert to probabilities
probs = F.softmax(logits, dim=-1)
# sample from the distribution or take the most likely
if sample:
shape = probs.shape
probs = probs.reshape(shape[0]*shape[1],shape[2])
ix = torch.multinomial(probs, num_samples=1)
probs = probs.reshape(shape[0],shape[1],shape[2])
ix = ix.reshape(shape[0],shape[1])
else:
_, ix = torch.topk(probs, k=1, dim=-1)
# cut off conditioning
x = ix[:, c.shape[1]-1:]
else:
for k in range(steps):
callback(k)
assert x.size(1) <= block_size # make sure model can see conditioning
x_cond = x if x.size(1) <= block_size else x[:, -block_size:] # crop context if needed
logits, _ = self.transformer(x_cond)
# pluck the logits at the final step and scale by temperature
logits = logits[:, -1, :] / temperature
# optionally crop probabilities to only the top k options
if top_k is not None:
logits = self.top_k_logits(logits, top_k)
# apply softmax to convert to probabilities
probs = F.softmax(logits, dim=-1)
# sample from the distribution or take the most likely
if sample:
ix = torch.multinomial(probs, num_samples=1)
else:
_, ix = torch.topk(probs, k=1, dim=-1)
# append to the sequence and continue
x = torch.cat((x, ix), dim=1)
# cut off conditioning
x = x[:, c.shape[1]:]
return x
@torch.no_grad()
def encode_to_z(self, x):
quant_z, _, info = self.first_stage_model.encode(x)
indices = info[2].view(quant_z.shape[0], -1)
indices = self.permuter(indices)
return quant_z, indices
@torch.no_grad()
def encode_to_c(self, c):
if self.downsample_cond_size > -1:
c = F.interpolate(c, size=(self.downsample_cond_size, self.downsample_cond_size))
quant_c, _, [_,_,indices] = self.cond_stage_model.encode(c)
if len(indices.shape) > 2:
indices = indices.view(c.shape[0], -1)
return quant_c, indices
@torch.no_grad()
def decode_to_img(self, index, zshape):
index = self.permuter(index, reverse=True)
bhwc = (zshape[0],zshape[2],zshape[3],zshape[1])
quant_z = self.first_stage_model.quantize.get_codebook_entry(
index.reshape(-1), shape=bhwc)
x = self.first_stage_model.decode(quant_z)
return x
@torch.no_grad()
def log_images(self, batch, temperature=None, top_k=None, callback=None, lr_interface=False, **kwargs):
log = dict()
N = 4
if lr_interface:
x, c = self.get_xc(batch, N, diffuse=False, upsample_factor=8)
else:
x, c = self.get_xc(batch, N)
x = x.to(device=self.device)
c = c.to(device=self.device)
quant_z, z_indices = self.encode_to_z(x)
quant_c, c_indices = self.encode_to_c(c)
# create a "half"" sample
z_start_indices = z_indices[:,:z_indices.shape[1]//2]
index_sample = self.sample(z_start_indices, c_indices,
steps=z_indices.shape[1]-z_start_indices.shape[1],
temperature=temperature if temperature is not None else 1.0,
sample=True,
top_k=top_k if top_k is not None else 100,
callback=callback if callback is not None else lambda k: None)
x_sample = self.decode_to_img(index_sample, quant_z.shape)
# sample
z_start_indices = z_indices[:, :0]
index_sample = self.sample(z_start_indices, c_indices,
steps=z_indices.shape[1],
temperature=temperature if temperature is not None else 1.0,
sample=True,
top_k=top_k if top_k is not None else 100,
callback=callback if callback is not None else lambda k: None)
x_sample_nopix = self.decode_to_img(index_sample, quant_z.shape)
# det sample
z_start_indices = z_indices[:, :0]
index_sample = self.sample(z_start_indices, c_indices,
steps=z_indices.shape[1],
sample=False,
callback=callback if callback is not None else lambda k: None)
x_sample_det = self.decode_to_img(index_sample, quant_z.shape)
# reconstruction
x_rec = self.decode_to_img(z_indices, quant_z.shape)
log["inputs"] = x
log["reconstructions"] = x_rec
if self.cond_stage_key in ["objects_bbox", "objects_center_points"]:
figure_size = (x_rec.shape[2], x_rec.shape[3])
dataset = kwargs["pl_module"].trainer.datamodule.datasets["validation"]
label_for_category_no = dataset.get_textual_label_for_category_no
plotter = dataset.conditional_builders[self.cond_stage_key].plot
log["conditioning"] = torch.zeros_like(log["reconstructions"])
for i in range(quant_c.shape[0]):
log["conditioning"][i] = plotter(quant_c[i], label_for_category_no, figure_size)
log["conditioning_rec"] = log["conditioning"]
elif self.cond_stage_key != "image":
cond_rec = self.cond_stage_model.decode(quant_c)
if self.cond_stage_key == "segmentation":
# get image from segmentation mask
num_classes = cond_rec.shape[1]
c = torch.argmax(c, dim=1, keepdim=True)
c = F.one_hot(c, num_classes=num_classes)
c = c.squeeze(1).permute(0, 3, 1, 2).float()
c = self.cond_stage_model.to_rgb(c)
cond_rec = torch.argmax(cond_rec, dim=1, keepdim=True)
cond_rec = F.one_hot(cond_rec, num_classes=num_classes)
cond_rec = cond_rec.squeeze(1).permute(0, 3, 1, 2).float()
cond_rec = self.cond_stage_model.to_rgb(cond_rec)
log["conditioning_rec"] = cond_rec
log["conditioning"] = c
log["samples_half"] = x_sample
log["samples_nopix"] = x_sample_nopix
log["samples_det"] = x_sample_det
return log
def get_input(self, key, batch):
x = batch[key]
if len(x.shape) == 3:
x = x[..., None]
if len(x.shape) == 4:
x = x.permute(0, 3, 1, 2).to(memory_format=torch.contiguous_format)
if x.dtype == torch.double:
x = x.float()
return x
def get_xc(self, batch, N=None):
x = self.get_input(self.first_stage_key, batch)
c = self.get_input(self.cond_stage_key, batch)
if N is not None:
x = x[:N]
c = c[:N]
return x, c
def shared_step(self, batch, batch_idx):
x, c = self.get_xc(batch)
logits, target = self(x, c)
loss = F.cross_entropy(logits.reshape(-1, logits.size(-1)), target.reshape(-1))
return loss
def training_step(self, batch, batch_idx):
loss = self.shared_step(batch, batch_idx)
self.log("train/loss", loss, prog_bar=True, logger=True, on_step=True, on_epoch=True)
return loss
def validation_step(self, batch, batch_idx):
loss = self.shared_step(batch, batch_idx)
self.log("val/loss", loss, prog_bar=True, logger=True, on_step=True, on_epoch=True)
return loss
def configure_optimizers(self):
"""
Following minGPT:
This long function is unfortunately doing something very simple and is being very defensive:
We are separating out all parameters of the model into two buckets: those that will experience
weight decay for regularization and those that won't (biases, and layernorm/embedding weights).
We are then returning the PyTorch optimizer object.
"""
# separate out all parameters to those that will and won't experience regularizing weight decay
decay = set()
no_decay = set()
whitelist_weight_modules = (torch.nn.Linear, )
blacklist_weight_modules = (torch.nn.LayerNorm, torch.nn.Embedding)
for mn, m in self.transformer.named_modules():
for pn, p in m.named_parameters():
fpn = '%s.%s' % (mn, pn) if mn else pn # full param name
if pn.endswith('bias'):
# all biases will not be decayed
no_decay.add(fpn)
elif pn.endswith('weight') and isinstance(m, whitelist_weight_modules):
# weights of whitelist modules will be weight decayed
decay.add(fpn)
elif pn.endswith('weight') and isinstance(m, blacklist_weight_modules):
# weights of blacklist modules will NOT be weight decayed
no_decay.add(fpn)
# special case the position embedding parameter in the root GPT module as not decayed
no_decay.add('pos_emb')
# validate that we considered every parameter
param_dict = {pn: p for pn, p in self.transformer.named_parameters()}
inter_params = decay & no_decay
union_params = decay | no_decay
assert len(inter_params) == 0, "parameters %s made it into both decay/no_decay sets!" % (str(inter_params), )
assert len(param_dict.keys() - union_params) == 0, "parameters %s were not separated into either decay/no_decay set!" \
% (str(param_dict.keys() - union_params), )
# create the pytorch optimizer object
optim_groups = [
{"params": [param_dict[pn] for pn in sorted(list(decay))], "weight_decay": 0.01},
{"params": [param_dict[pn] for pn in sorted(list(no_decay))], "weight_decay": 0.0},
]
optimizer = torch.optim.AdamW(optim_groups, lr=self.learning_rate, betas=(0.9, 0.95))
return optimizer