DL-Art-School/codes/models/diffusion/diffusion_dvae.py
2021-09-16 22:43:10 -06:00

342 lines
14 KiB
Python

from models.diffusion.fp16_util import convert_module_to_f32, convert_module_to_f16
from models.diffusion.nn import timestep_embedding, normalization, zero_module, conv_nd, linear
from models.diffusion.unet_diffusion import AttentionPool2d, AttentionBlock, ResBlock, TimestepEmbedSequential, \
Downsample, Upsample
import torch
import torch.nn as nn
from models.gpt_voice.mini_encoder import AudioMiniEncoder, EmbeddingCombiner
from models.vqvae.vqvae import Quantize
from trainer.networks import register_model
import models.gpt_voice.my_dvae as mdvae
from utils.util import checkpoint, get_mask_from_lengths
class DiscreteEncoder(nn.Module):
def __init__(self,
in_channels,
model_channels,
out_channels,
dropout,
scale):
super().__init__()
self.blocks = nn.Sequential(
conv_nd(1, in_channels, model_channels, 3, padding=1),
mdvae.ResBlock(model_channels, dropout, dims=1),
Downsample(model_channels, use_conv=True, dims=1, out_channels=model_channels*2, factor=scale),
mdvae.ResBlock(model_channels*2, dropout, dims=1),
Downsample(model_channels*2, use_conv=True, dims=1, out_channels=model_channels*4, factor=scale),
mdvae.ResBlock(model_channels*4, dropout, dims=1),
AttentionBlock(model_channels*4, num_heads=4),
mdvae.ResBlock(model_channels*4, dropout, out_channels=out_channels, dims=1),
)
def forward(self, spectrogram):
return checkpoint(self.blocks, spectrogram)
class DiscreteDecoder(nn.Module):
def __init__(self, in_channels, level_channels, scale):
super().__init__()
# Just raw upsampling, return a dict with each layer.
self.init = conv_nd(1, in_channels, level_channels[0], kernel_size=3, padding=1)
layers = []
for i, lvl in enumerate(level_channels[:-1]):
layers.append(nn.Sequential(normalization(lvl),
nn.SiLU(lvl),
Upsample(lvl, use_conv=True, dims=1, out_channels=level_channels[i+1], factor=scale)))
self.layers = nn.ModuleList(layers)
def forward(self, x):
y = self.init(x)
outs = [y]
for layer in self.layers:
y = layer(y)
outs.append(y)
return outs
class DiffusionDVAE(nn.Module):
def __init__(
self,
model_channels,
num_res_blocks,
in_channels=1,
out_channels=2, # mean and variance
spectrogram_channels=80,
spectrogram_conditioning_levels=[3,4,5], # Levels at which spectrogram conditioning is applied to the waveform.
dropout=0,
channel_mult=(1, 2, 4, 8, 16, 32, 64),
attention_resolutions=(16,32,64),
conv_resample=True,
dims=1,
use_fp16=False,
num_heads=1,
num_head_channels=-1,
num_heads_upsample=-1,
use_scale_shift_norm=False,
use_new_attention_order=False,
kernel_size=5,
quantize_dim=1024,
num_discrete_codes=8192,
scale_steps=4,
conditioning_inputs_provided=True,
):
super().__init__()
if num_heads_upsample == -1:
num_heads_upsample = num_heads
self.in_channels = in_channels
self.spectrogram_channels = spectrogram_channels
self.model_channels = model_channels
self.out_channels = out_channels
self.num_res_blocks = num_res_blocks
self.attention_resolutions = attention_resolutions
self.dropout = dropout
self.channel_mult = channel_mult
self.conv_resample = conv_resample
self.dtype = torch.float16 if use_fp16 else torch.float32
self.num_heads = num_heads
self.num_head_channels = num_head_channels
self.num_heads_upsample = num_heads_upsample
self.dims = dims
self.spectrogram_conditioning_levels = spectrogram_conditioning_levels
self.scale_steps = scale_steps
self.encoder = DiscreteEncoder(spectrogram_channels, model_channels*4, quantize_dim, dropout, scale_steps)
self.quantizer = Quantize(quantize_dim, num_discrete_codes)
# For recording codebook usage.
self.codes = torch.zeros((131072,), dtype=torch.long)
self.code_ind = 0
self.internal_step = 0
decoder_channels = [model_channels * channel_mult[s-1] for s in spectrogram_conditioning_levels]
self.decoder = DiscreteDecoder(quantize_dim, decoder_channels[::-1], scale_steps)
padding = 1 if kernel_size == 3 else 2
time_embed_dim = model_channels * 4
self.time_embed = nn.Sequential(
linear(model_channels, time_embed_dim),
nn.SiLU(),
linear(time_embed_dim, time_embed_dim),
)
if conditioning_inputs_provided:
self.contextual_embedder = AudioMiniEncoder(self.spectrogram_channels, time_embed_dim)
self.query_gen = AudioMiniEncoder(decoder_channels[0], time_embed_dim)
self.embedding_combiner = EmbeddingCombiner(time_embed_dim)
self.input_blocks = nn.ModuleList(
[
TimestepEmbedSequential(
conv_nd(dims, in_channels, model_channels, kernel_size, padding=padding)
)
]
)
self._feature_size = model_channels
input_block_chans = [model_channels]
ch = model_channels
ds = 1
self.convergence_convs = nn.ModuleList([])
for level, mult in enumerate(channel_mult):
if level in spectrogram_conditioning_levels:
self.convergence_convs.append(conv_nd(dims, ch*2, ch, 1))
for _ in range(num_res_blocks):
layers = [
ResBlock(
ch,
time_embed_dim,
dropout,
out_channels=mult * model_channels,
dims=dims,
use_scale_shift_norm=use_scale_shift_norm,
kernel_size=kernel_size,
)
]
ch = mult * model_channels
if ds in attention_resolutions:
layers.append(
AttentionBlock(
ch,
num_heads=num_heads,
num_head_channels=num_head_channels,
use_new_attention_order=use_new_attention_order,
)
)
self.input_blocks.append(TimestepEmbedSequential(*layers))
self._feature_size += ch
input_block_chans.append(ch)
if level != len(channel_mult) - 1:
out_ch = ch
self.input_blocks.append(
TimestepEmbedSequential(
Downsample(
ch, conv_resample, dims=dims, out_channels=out_ch, factor=scale_steps
)
)
)
ch = out_ch
input_block_chans.append(ch)
ds *= 2
self._feature_size += ch
self.middle_block = TimestepEmbedSequential(
ResBlock(
ch,
time_embed_dim,
dropout,
dims=dims,
use_scale_shift_norm=use_scale_shift_norm,
kernel_size=kernel_size,
),
AttentionBlock(
ch,
num_heads=num_heads,
num_head_channels=num_head_channels,
use_new_attention_order=use_new_attention_order,
),
ResBlock(
ch,
time_embed_dim,
dropout,
dims=dims,
use_scale_shift_norm=use_scale_shift_norm,
kernel_size=kernel_size,
),
)
self._feature_size += ch
self.output_blocks = nn.ModuleList([])
for level, mult in list(enumerate(channel_mult))[::-1]:
for i in range(num_res_blocks + 1):
ich = input_block_chans.pop()
layers = [
ResBlock(
ch + ich,
time_embed_dim,
dropout,
out_channels=model_channels * mult,
dims=dims,
use_scale_shift_norm=use_scale_shift_norm,
kernel_size=kernel_size,
)
]
ch = model_channels * mult
if ds in attention_resolutions:
layers.append(
AttentionBlock(
ch,
num_heads=num_heads_upsample,
num_head_channels=num_head_channels,
use_new_attention_order=use_new_attention_order,
)
)
if level and i == num_res_blocks:
out_ch = ch
layers.append(
Upsample(ch, conv_resample, dims=dims, out_channels=out_ch, factor=scale_steps)
)
ds //= 2
self.output_blocks.append(TimestepEmbedSequential(*layers))
self._feature_size += ch
self.out = nn.Sequential(
normalization(ch),
nn.SiLU(),
zero_module(conv_nd(dims, model_channels, out_channels, kernel_size, padding=padding)),
)
def convert_to_fp16(self):
"""
Convert the torso of the model to float16.
"""
self.input_blocks.apply(convert_module_to_f16)
self.middle_block.apply(convert_module_to_f16)
self.output_blocks.apply(convert_module_to_f16)
def convert_to_fp32(self):
"""
Convert the torso of the model to float32.
"""
self.input_blocks.apply(convert_module_to_f32)
self.middle_block.apply(convert_module_to_f32)
self.output_blocks.apply(convert_module_to_f32)
def _decode_continouous(self, x, timesteps, embeddings, conditioning_inputs, num_conditioning_signals):
spec_hs = self.decoder(embeddings)[::-1]
# Shape the spectrogram correctly. There is no guarantee it fits (though I probably should add an assertion here to make sure the resizing isn't too wacky.)
spec_hs = [nn.functional.interpolate(sh, size=(x.shape[-1]//self.scale_steps**self.spectrogram_conditioning_levels[i],), mode='nearest') for i, sh in enumerate(spec_hs)]
convergence_fns = list(self.convergence_convs)
# Timestep embeddings and conditioning signals are combined using a small transformer.
hs = []
emb1 = self.time_embed(timestep_embedding(timesteps, self.model_channels))
if conditioning_inputs is not None:
mask = get_mask_from_lengths(num_conditioning_signals+1, conditioning_inputs.shape[1]+1) # +1 to account for the timestep embeddings we'll add.
emb2 = torch.stack([self.contextual_embedder(ci.squeeze(1)) for ci in list(torch.chunk(conditioning_inputs, conditioning_inputs.shape[1], dim=1))], dim=1)
emb = torch.cat([emb1.unsqueeze(1), emb2], dim=1)
emb = self.embedding_combiner(emb, mask, self.query_gen(spec_hs[0]))
else:
emb = emb1
# The rest is the diffusion vocoder, built as a standard U-net. spec_h is gradually fed into the encoder.
next_spec = spec_hs.pop(0)
next_convergence_fn = convergence_fns.pop(0)
h = x.type(self.dtype)
for k, module in enumerate(self.input_blocks):
h = module(h, emb)
if next_spec is not None and h.shape[-1] == next_spec.shape[-1]:
h = torch.cat([h, next_spec], dim=1)
h = next_convergence_fn(h)
if len(spec_hs) > 0:
next_spec = spec_hs.pop(0)
next_convergence_fn = convergence_fns.pop(0)
else:
next_spec = None
hs.append(h)
assert len(spec_hs) == 0
assert len(convergence_fns) == 0
h = self.middle_block(h, emb)
for module in self.output_blocks:
h = torch.cat([h, hs.pop()], dim=1)
h = module(h, emb)
h = h.type(x.dtype)
return self.out(h)
def decode(self, x, timesteps, codes, conditioning_inputs=None, num_conditioning_signals=None):
assert x.shape[-1] % 4096 == 0 # This model operates at base//4096 at it's bottom levels, thus this requirement.
embeddings = self.quantizer.embed_code(codes).permute((0,2,1))
return self._decode_continouous(x, timesteps, embeddings, conditioning_inputs, num_conditioning_signals)
def forward(self, x, timesteps, spectrogram, conditioning_inputs=None, num_conditioning_signals=None):
assert x.shape[-1] % 4096 == 0 # This model operates at base//4096 at it's bottom levels, thus this requirement.
# Compute DVAE portion first.
spec_logits = self.encoder(spectrogram).permute((0,2,1))
sampled, commitment_loss, codes = self.quantizer(spec_logits)
if self.training:
# Compute from softmax outputs to preserve gradients.
embeddings = sampled.permute((0,2,1))
else:
# Compute from codes only.
embeddings = self.quantizer.embed_code(codes).permute((0,2,1))
return self._decode_continouous(x, timesteps, embeddings, conditioning_inputs, num_conditioning_signals), commitment_loss
@register_model
def register_unet_diffusion_dvae(opt_net, opt):
return DiffusionDVAE(**opt_net['kwargs'])
# Test for ~4 second audio clip at 22050Hz
if __name__ == '__main__':
clip = torch.randn(4, 1, 81920)
spec = torch.randn(4, 80, 416)
cond = torch.randn(4, 5, 80, 200)
num_cond = torch.tensor([2,4,5,3], dtype=torch.long)
ts = torch.LongTensor([432, 234, 100, 555])
model = DiffusionDVAE(32, 2)
print(model(clip, ts, spec, cond, num_cond)[0].shape)