271 lines
12 KiB
Python
271 lines
12 KiB
Python
import os
|
|
import random
|
|
|
|
import torch
|
|
import torch.nn as nn
|
|
import torch.nn.functional as F
|
|
import torchvision
|
|
from torch import autocast
|
|
|
|
from models.arch_util import ResBlock
|
|
from models.diffusion.nn import timestep_embedding, normalization, zero_module, conv_nd, linear
|
|
from models.diffusion.unet_diffusion import AttentionBlock, TimestepEmbedSequential, TimestepBlock
|
|
from models.lucidrains.x_transformers import Encoder, Attention
|
|
from scripts.audio.gen.use_mel2vec_codes import collapse_codegroups
|
|
from trainer.injectors.audio_injectors import normalize_mel
|
|
from trainer.networks import register_model
|
|
from utils.util import checkpoint
|
|
|
|
|
|
def is_latent(t):
|
|
return t.dtype == torch.float
|
|
|
|
def is_sequence(t):
|
|
return t.dtype == torch.long
|
|
|
|
|
|
class MultiGroupEmbedding(nn.Module):
|
|
def __init__(self, tokens, groups, dim):
|
|
super().__init__()
|
|
self.m = nn.ModuleList([nn.Embedding(tokens, dim // groups) for _ in range(groups)])
|
|
|
|
def forward(self, x):
|
|
h = [embedding(x[:, :, i]) for i, embedding in enumerate(self.m)]
|
|
return torch.cat(h, dim=-1)
|
|
|
|
|
|
class TransformerDiffusion(nn.Module):
|
|
"""
|
|
A diffusion model composed entirely of stacks of transformer layers. Why would you do it any other way?
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
model_channels=512,
|
|
num_layers=8,
|
|
in_channels=256,
|
|
in_latent_channels=512,
|
|
token_count=8,
|
|
in_groups=None,
|
|
out_channels=512, # mean and variance
|
|
dropout=0,
|
|
use_fp16=False,
|
|
# Parameters for regularization.
|
|
unconditioned_percentage=.1, # This implements a mechanism similar to what is used in classifier-free training.
|
|
):
|
|
super().__init__()
|
|
|
|
self.in_channels = in_channels
|
|
self.model_channels = model_channels
|
|
self.out_channels = out_channels
|
|
self.dropout = dropout
|
|
self.unconditioned_percentage = unconditioned_percentage
|
|
self.enable_fp16 = use_fp16
|
|
heads = model_channels//64
|
|
|
|
self.inp_block = conv_nd(1, in_channels, model_channels, 3, 1, 1)
|
|
|
|
self.time_embed = nn.Sequential(
|
|
linear(model_channels, model_channels),
|
|
nn.SiLU(),
|
|
linear(model_channels, model_channels),
|
|
)
|
|
self.conditioning_embedder = nn.Sequential(nn.Conv1d(in_channels, model_channels // 2, 3, padding=1, stride=2),
|
|
nn.Conv1d(model_channels//2, model_channels,3,padding=1,stride=2))
|
|
self.conditioning_encoder = Encoder(
|
|
dim=model_channels,
|
|
depth=4,
|
|
heads=heads,
|
|
ff_dropout=dropout,
|
|
attn_dropout=dropout,
|
|
use_rmsnorm=True,
|
|
ff_glu=True,
|
|
rotary_pos_emb=True,
|
|
)
|
|
|
|
# Either code_converter or latent_converter is used, depending on what type of conditioning data is fed.
|
|
# This model is meant to be able to be trained on both for efficiency purposes - it is far less computationally
|
|
# complex to generate tokens, while generating latents will normally mean propagating through a deep autoregressive
|
|
# transformer network.
|
|
if in_groups is None:
|
|
self.embeddings = nn.Embedding(token_count, model_channels)
|
|
else:
|
|
self.embeddings = MultiGroupEmbedding(token_count, in_groups, model_channels)
|
|
self.latent_conditioner = nn.Sequential(
|
|
nn.Conv1d(in_latent_channels, model_channels, 3, padding=1),
|
|
Encoder(
|
|
dim=model_channels,
|
|
depth=2,
|
|
heads=heads,
|
|
ff_dropout=dropout,
|
|
attn_dropout=dropout,
|
|
use_rmsnorm=True,
|
|
ff_glu=True,
|
|
rotary_pos_emb=True,
|
|
)
|
|
)
|
|
self.latent_fade = nn.Parameter(torch.zeros(1,1,model_channels))
|
|
self.code_converter = Encoder(
|
|
dim=model_channels,
|
|
depth=3,
|
|
heads=heads,
|
|
ff_dropout=dropout,
|
|
attn_dropout=dropout,
|
|
use_rmsnorm=True,
|
|
ff_glu=True,
|
|
rotary_pos_emb=True,
|
|
)
|
|
|
|
self.unconditioned_embedding = nn.Parameter(torch.randn(1,1,model_channels))
|
|
self.integrator = nn.Linear(model_channels * 2, model_channels)
|
|
self.mel_head = nn.Conv1d(model_channels, in_channels, kernel_size=3, padding=1)
|
|
|
|
self.layers = Encoder(
|
|
dim=model_channels,
|
|
depth=num_layers,
|
|
heads=heads,
|
|
ff_dropout=dropout,
|
|
attn_dropout=dropout,
|
|
use_rms_scaleshift_norm=True,
|
|
ff_glu=True,
|
|
rotary_pos_emb=True,
|
|
zero_init_branch_output=True,
|
|
)
|
|
|
|
self.out = nn.Sequential(
|
|
normalization(model_channels),
|
|
nn.SiLU(),
|
|
zero_module(conv_nd(1, model_channels, out_channels, 3, padding=1)),
|
|
)
|
|
|
|
self.debug_codes = {}
|
|
|
|
def get_grad_norm_parameter_groups(self):
|
|
groups = {
|
|
'contextual_embedder': list(self.conditioning_embedder.parameters()),
|
|
'layers': list(self.layers.parameters()) + list(self.integrator.parameters()) + list(self.inp_block.parameters()),
|
|
'code_converters': list(self.embeddings.parameters()) + list(self.code_converter.parameters()) + list(self.latent_conditioner.parameters()),
|
|
'time_embed': list(self.time_embed.parameters()),
|
|
}
|
|
return groups
|
|
|
|
def timestep_independent(self, codes, conditioning_input, expected_seq_len, prenet_latent=None, return_code_pred=False):
|
|
cond_emb = self.conditioning_embedder(conditioning_input).permute(0,2,1)
|
|
cond_emb = self.conditioning_encoder(cond_emb)[:, 0]
|
|
|
|
code_emb = self.embeddings(codes)
|
|
if prenet_latent is not None:
|
|
latent_conditioning = self.latent_conditioner(prenet_latent)
|
|
code_emb = code_emb + latent_conditioning * self.latent_fade
|
|
|
|
unconditioned_batches = torch.zeros((code_emb.shape[0], 1, 1), device=code_emb.device)
|
|
# Mask out the conditioning branch for whole batch elements, implementing something similar to classifier-free guidance.
|
|
if self.training and self.unconditioned_percentage > 0:
|
|
unconditioned_batches = torch.rand((code_emb.shape[0], 1, 1),
|
|
device=code_emb.device) < self.unconditioned_percentage
|
|
code_emb = torch.where(unconditioned_batches, self.unconditioned_embedding.repeat(codes.shape[0], 1, 1),
|
|
code_emb)
|
|
code_emb = self.code_converter(code_emb)
|
|
|
|
expanded_code_emb = F.interpolate(code_emb.permute(0,2,1), size=expected_seq_len, mode='nearest').permute(0,2,1)
|
|
if not return_code_pred:
|
|
return expanded_code_emb, cond_emb
|
|
else:
|
|
# Perform the mel_head computation on the pre-exanded code embeddings, then interpolate it separately.
|
|
mel_pred = self.mel_head(code_emb.permute(0,2,1))
|
|
mel_pred = F.interpolate(mel_pred, size=expected_seq_len, mode='nearest')
|
|
# Multiply mel_pred by !unconditioned_branches, which drops the gradient on unconditioned branches.
|
|
# This is because we don't want that gradient being used to train parameters through the codes_embedder as
|
|
# it unbalances contributions to that network from the MSE loss.
|
|
mel_pred = mel_pred * unconditioned_batches.logical_not()
|
|
return expanded_code_emb, cond_emb, mel_pred
|
|
|
|
|
|
def forward(self, x, timesteps,
|
|
codes=None, conditioning_input=None, prenet_latent=None,
|
|
precomputed_code_embeddings=None, precomputed_cond_embeddings=None,
|
|
conditioning_free=False, return_code_pred=False):
|
|
"""
|
|
Apply the model to an input batch.
|
|
|
|
There are two ways to call this method:
|
|
1) Specify codes, conditioning_input and optionally prenet_latent
|
|
2) Specify precomputed_code_embeddings and precomputed_cond_embeddings, retrieved by calling timestep_independent yourself.
|
|
|
|
:param x: an [N x C x ...] Tensor of inputs.
|
|
:param timesteps: a 1-D batch of timesteps.
|
|
:param codes: an aligned latent or sequence of tokens providing useful data about the sample to be produced.
|
|
:param conditioning_input: a full-resolution audio clip that is used as a reference to the style you want decoded.
|
|
:param prenet_latent: optional latent vector aligned with codes derived from a prior network.
|
|
:param precomputed_code_embeddings: Code embeddings returned from self.timestep_independent()
|
|
:param precomputed_cond_embeddings: Conditional embeddings returned from self.timestep_independent()
|
|
:param conditioning_free: When set, all conditioning inputs (including tokens and conditioning_input) will not be considered.
|
|
:return: an [N x C x ...] Tensor of outputs.
|
|
"""
|
|
if precomputed_code_embeddings is not None:
|
|
assert precomputed_cond_embeddings is not None, "Must specify both precomputed embeddings if one is specified"
|
|
assert codes is None and conditioning_input is None and prenet_latent is None, "Do not provide precomputed embeddings and the other parameters. It is unclear what you want me to do here."
|
|
assert not (return_code_pred and precomputed_code_embeddings is not None), "I cannot compute a code_pred output for you."
|
|
|
|
unused_params = []
|
|
if not return_code_pred:
|
|
unused_params.extend(list(self.mel_head.parameters()))
|
|
if conditioning_free:
|
|
code_emb = self.unconditioned_embedding.repeat(x.shape[0], 1, x.shape[-1])
|
|
unused_params.extend(list(self.code_converter.parameters()) + list(self.code_embedding.parameters()))
|
|
unused_params.extend(list(self.latent_conditioner.parameters()))
|
|
else:
|
|
if precomputed_code_embeddings is not None:
|
|
code_emb = precomputed_code_embeddings
|
|
cond_emb = precomputed_cond_embeddings
|
|
else:
|
|
code_emb, cond_emb, mel_pred = self.timestep_independent(codes, conditioning_input, x.shape[-1], prenet_latent, True)
|
|
if prenet_latent is None:
|
|
unused_params.extend(list(self.latent_conditioner.parameters()) + [self.latent_fade])
|
|
unused_params.append(self.unconditioned_embedding)
|
|
|
|
blk_emb = self.time_embed(timestep_embedding(timesteps, self.model_channels)) + cond_emb
|
|
x = self.inp_block(x).permute(0,2,1)
|
|
x = torch.cat([x, code_emb], dim=2)
|
|
x = self.integrator(x)
|
|
x = self.layers(x, norm_scale_shift_inp=blk_emb)
|
|
|
|
x = x.float().permute(0,2,1)
|
|
out = self.out(x)
|
|
|
|
# Involve probabilistic or possibly unused parameters in loss so we don't get DDP errors.
|
|
extraneous_addition = 0
|
|
for p in unused_params:
|
|
extraneous_addition = extraneous_addition + p.mean()
|
|
out = out + extraneous_addition * 0
|
|
|
|
if return_code_pred:
|
|
return out, mel_pred
|
|
return out
|
|
|
|
def get_conditioning_latent(self, conditioning_input):
|
|
speech_conditioning_input = conditioning_input.unsqueeze(1) if len(
|
|
conditioning_input.shape) == 3 else conditioning_input
|
|
conds = []
|
|
for j in range(speech_conditioning_input.shape[1]):
|
|
conds.append(self.conditioning_embedder(speech_conditioning_input[:, j]))
|
|
conds = torch.cat(conds, dim=-1)
|
|
return conds.mean(dim=-1)
|
|
|
|
|
|
@register_model
|
|
def register_transformer_diffusion(opt_net, opt):
|
|
return TransformerDiffusion(**opt_net['kwargs'])
|
|
|
|
|
|
if __name__ == '__main__':
|
|
clip = torch.randn(2, 256, 400)
|
|
aligned_latent = torch.randn(2,100,512)
|
|
aligned_sequence = torch.randint(0,8,(2,100,8))
|
|
cond = torch.randn(2, 256, 400)
|
|
ts = torch.LongTensor([600, 600])
|
|
model = TransformerDiffusion(512, unconditioned_percentage=.5, in_groups=8)
|
|
o = model(clip, ts, aligned_sequence, cond, return_code_pred=True)
|
|
#o = model(clip, ts, aligned_sequence, cond, aligned_latent)
|
|
|