Never used

This commit is contained in:
City
2023-11-22 20:58:21 +01:00
parent 4c711dddc4
commit 33e5db52a3
+2 -382
View File
@@ -162,11 +162,9 @@ class VideoDecoder(nn.Module):
)) ))
block_in = block_out block_in = block_out
if curr_res in attn_resolutions: if curr_res in attn_resolutions:
attn.append(make_time_attn( attn.append(make_attn(
block_in, block_in,
attn_type=attn_type, attn_type=attn_type,
alpha=self.alpha,
merge_strategy=self.merge_strategy,
)) ))
up = nn.Module() up = nn.Module()
up.block = block up.block = block
@@ -217,7 +215,7 @@ class VideoDecoder(nn.Module):
for i_block in range(self.num_res_blocks+1): for i_block in range(self.num_res_blocks+1):
h = self.up[i_level].block[i_block](h, temb, **kwargs) h = self.up[i_level].block[i_block](h, temb, **kwargs)
if len(self.up[i_level].attn) > 0: if len(self.up[i_level].attn) > 0:
h = self.up[i_level].attn[i_block](h, **kwargs) h = self.up[i_level].attn[i_block](h)
if i_level != 0: if i_level != 0:
h = self.up[i_level].upsample(h) h = self.up[i_level].upsample(h)
@@ -232,318 +230,6 @@ class VideoDecoder(nn.Module):
h = torch.tanh(h) h = torch.tanh(h)
return h return h
class CrossAttention(nn.Module):
def __init__(
self,
query_dim,
context_dim=None,
heads=8,
dim_head=64,
dropout=0.0,
backend=None,
):
super().__init__()
inner_dim = dim_head * heads
context_dim = context_dim or query_dim
self.scale = dim_head**-0.5
self.heads = heads
self.to_q = nn.Linear(query_dim, inner_dim, bias=False)
self.to_k = nn.Linear(context_dim, inner_dim, bias=False)
self.to_v = nn.Linear(context_dim, inner_dim, bias=False)
self.to_out = nn.Sequential(
nn.Linear(inner_dim, query_dim), nn.Dropout(dropout)
)
self.backend = backend
def forward(
self,
x,
context=None,
mask=None,
additional_tokens=None,
n_times_crossframe_attn_in_self=0,
):
h = self.heads
if additional_tokens is not None:
# get the number of masked tokens at the beginning of the output sequence
n_tokens_to_mask = additional_tokens.shape[1]
# add additional token
x = torch.cat([additional_tokens, x], dim=1)
q = self.to_q(x)
context = context or x
k = self.to_k(context)
v = self.to_v(context)
if n_times_crossframe_attn_in_self:
# reprogramming cross-frame attention as in https://arxiv.org/abs/2303.13439
assert x.shape[0] % n_times_crossframe_attn_in_self == 0
n_cp = x.shape[0] // n_times_crossframe_attn_in_self
k = repeat(
k[::n_times_crossframe_attn_in_self], "b ... -> (b n) ...", n=n_cp
)
v = repeat(
v[::n_times_crossframe_attn_in_self], "b ... -> (b n) ...", n=n_cp
)
q, k, v = map(lambda t: rearrange(t, "b n (h d) -> b h n d", h=h), (q, k, v))
## old
"""
sim = einsum('b i d, b j d -> b i j', q, k) * self.scale
del q, k
if exists(mask):
mask = rearrange(mask, 'b ... -> b (...)')
max_neg_value = -torch.finfo(sim.dtype).max
mask = repeat(mask, 'b j -> (b h) () j', h=h)
sim.masked_fill_(~mask, max_neg_value)
# some quote about attention, that I just about had enough of
sim = sim.softmax(dim=-1)
out = einsum('b i j, b j d -> b i d', sim, v)
"""
## new
with sdp_kernel(**BACKEND_MAP[self.backend]):
# print("dispatching into backend", self.backend, "q/k/v shape: ", q.shape, k.shape, v.shape)
out = F.scaled_dot_product_attention(
q, k, v, attn_mask=mask
) # scale is dim_head ** -0.5 per default
del q, k, v
out = rearrange(out, "b h n d -> b n (h d)", h=h)
if additional_tokens is not None:
# remove additional token
out = out[:, n_tokens_to_mask:]
return self.to_out(out)
class VideoBlock(AttnBlock):
def __init__(
self, in_channels: int, alpha: float = 0, merge_strategy: str = "learned"
):
super().__init__(in_channels)
# no context, single headed, as in base class
self.time_mix_block = VideoTransformerBlock(
dim=in_channels,
n_heads=1,
d_head=in_channels,
checkpoint=False,
ff_in=True,
attn_mode="softmax",
)
time_embed_dim = self.in_channels * 4
self.video_time_embed = torch.nn.Sequential(
torch.nn.Linear(self.in_channels, time_embed_dim),
torch.nn.SiLU(),
torch.nn.Linear(time_embed_dim, self.in_channels),
)
self.merge_strategy = merge_strategy
if self.merge_strategy == "fixed":
self.register_buffer("mix_factor", torch.Tensor([alpha]))
elif self.merge_strategy == "learned":
self.register_parameter(
"mix_factor", torch.nn.Parameter(torch.Tensor([alpha]))
)
else:
raise ValueError(f"unknown merge strategy {self.merge_strategy}")
def forward(self, x, timesteps, skip_video=False):
if skip_video:
return super().forward(x)
x_in = x
x = self.attention(x)
h, w = x.shape[2:]
x = rearrange(x, "b c h w -> b (h w) c")
x_mix = x
num_frames = torch.arange(timesteps, device=x.device)
num_frames = repeat(num_frames, "t -> b t", b=x.shape[0] // timesteps)
num_frames = rearrange(num_frames, "b t -> (b t)")
t_emb = timestep_embedding(num_frames, self.in_channels, repeat_only=False)
emb = self.video_time_embed(t_emb) # b, n_channels
emb = emb[:, None, :]
x_mix = x_mix + emb
alpha = self.get_alpha()
x_mix = self.time_mix_block(x_mix, timesteps=timesteps)
x = alpha * x + (1.0 - alpha) * x_mix # alpha merge
x = rearrange(x, "b (h w) c -> b c h w", h=h, w=w)
x = self.proj_out(x)
return x_in + x
def attention(self, h_: torch.Tensor) -> torch.Tensor:
h_ = self.norm(h_)
q = self.q(h_)
k = self.k(h_)
v = self.v(h_)
b, c, h, w = q.shape
q, k, v = map(
lambda x: rearrange(x, "b c h w -> b 1 (h w) c").contiguous(), (q, k, v)
)
h_ = torch.nn.functional.scaled_dot_product_attention(
q, k, v
) # scale is dim ** -0.5 per default
# compute attention
return rearrange(h_, "b 1 (h w) c -> b c h w", h=h, w=w, c=c, b=b)
def forward(self, x, **kwargs):
h_ = x
h_ = self.attention(h_)
h_ = self.proj_out(h_)
return x + h_
def get_alpha(
self,
):
if self.merge_strategy == "fixed":
return self.mix_factor
elif self.merge_strategy == "learned":
return torch.sigmoid(self.mix_factor)
else:
raise NotImplementedError(f"unknown merge strategy {self.merge_strategy}")
class VideoTransformerBlock(nn.Module):
ATTENTION_MODES = {
"softmax": CrossAttention,
# "softmax-xformers": MemoryEfficientCrossAttention,
}
def __init__(
self,
dim,
n_heads,
d_head,
dropout=0.0,
context_dim=None,
gated_ff=True,
checkpoint=True,
timesteps=None,
ff_in=False,
inner_dim=None,
attn_mode="softmax",
disable_self_attn=False,
disable_temporal_crossattention=False,
switch_temporal_ca_to_sa=False,
):
super().__init__()
attn_cls = self.ATTENTION_MODES.get(attn_mode, "softmax")
self.ff_in = ff_in or inner_dim is not None
if inner_dim is None:
inner_dim = dim
assert int(n_heads * d_head) == inner_dim
self.is_res = inner_dim == dim
if self.ff_in:
self.norm_in = nn.LayerNorm(dim)
self.ff_in = FeedForward(
dim, dim_out=inner_dim, dropout=dropout, glu=gated_ff
)
self.timesteps = timesteps
self.disable_self_attn = disable_self_attn
if self.disable_self_attn:
self.attn1 = attn_cls(
query_dim=inner_dim,
heads=n_heads,
dim_head=d_head,
context_dim=context_dim,
dropout=dropout,
) # is a cross-attention
else:
self.attn1 = attn_cls(
query_dim=inner_dim, heads=n_heads, dim_head=d_head, dropout=dropout
) # is a self-attention
self.ff = FeedForward(inner_dim, dim_out=dim, dropout=dropout, glu=gated_ff)
if disable_temporal_crossattention:
if switch_temporal_ca_to_sa:
raise ValueError
else:
self.attn2 = None
else:
self.norm2 = nn.LayerNorm(inner_dim)
if switch_temporal_ca_to_sa:
self.attn2 = attn_cls(
query_dim=inner_dim, heads=n_heads, dim_head=d_head, dropout=dropout
) # is a self-attention
else:
self.attn2 = attn_cls(
query_dim=inner_dim,
context_dim=context_dim,
heads=n_heads,
dim_head=d_head,
dropout=dropout,
) # is self-attn if context is none
self.norm1 = nn.LayerNorm(inner_dim)
self.norm3 = nn.LayerNorm(inner_dim)
self.switch_temporal_ca_to_sa = switch_temporal_ca_to_sa
self.checkpoint = checkpoint
if self.checkpoint:
print(f"{self.__class__.__name__} is using checkpointing")
def forward(
self, x: torch.Tensor, context: torch.Tensor = None, timesteps: int = None
) -> torch.Tensor:
if self.checkpoint:
return checkpoint(self._forward, x, context, timesteps)
else:
return self._forward(x, context, timesteps=timesteps)
def _forward(self, x, context=None, timesteps=None):
assert self.timesteps or timesteps
assert not (self.timesteps and timesteps) or self.timesteps == timesteps
timesteps = self.timesteps or timesteps
B, S, C = x.shape
x = rearrange(x, "(b t) s c -> (b s) t c", t=timesteps)
if self.ff_in:
x_skip = x
x = self.ff_in(self.norm_in(x))
if self.is_res:
x += x_skip
if self.disable_self_attn:
x = self.attn1(self.norm1(x), context=context) + x
else:
x = self.attn1(self.norm1(x)) + x
if self.attn2 is not None:
if self.switch_temporal_ca_to_sa:
x = self.attn2(self.norm2(x)) + x
else:
x = self.attn2(self.norm2(x), context=context) + x
x_skip = x
x = self.ff(self.norm3(x))
if self.is_res:
x += x_skip
x = rearrange(
x, "(b s) t c -> (b t) s c", s=S, b=B // timesteps, c=C, t=timesteps
)
return x
def get_last_layer(self):
return self.ff.net[-1].weight
class ResBlock(nn.Module): class ResBlock(nn.Module):
""" """
@@ -781,44 +467,6 @@ class AE3DConv(torch.nn.Conv2d):
x = self.time_mix_conv(x) x = self.time_mix_conv(x)
return rearrange(x, "b c t h w -> (b t) c h w") return rearrange(x, "b c t h w -> (b t) c h w")
def make_time_attn(in_channels, attn_type="vanilla", attn_kwargs=None, alpha: float = 0, merge_strategy: str = "learned"):
if attn_type == "vanilla":
assert attn_kwargs is None
return VideoBlock(
in_channels,
alpha=alpha,
merge_strategy=merge_strategy,
)
# lazy to add the xformers code
else:
return NotImplementedError()
def timestep_embedding(timesteps, dim, max_period=10000, repeat_only=False):
"""
Create sinusoidal timestep embeddings.
:param timesteps: a 1-D Tensor of N indices, one per batch element.
These may be fractional.
:param dim: the dimension of the output.
:param max_period: controls the minimum frequency of the embeddings.
:return: an [N x dim] Tensor of positional embeddings.
"""
if not repeat_only:
half = dim // 2
freqs = torch.exp(
-math.log(max_period)
* torch.arange(start=0, end=half, dtype=torch.float32)
/ half
).to(device=timesteps.device)
args = timesteps[:, None].float() * freqs[None]
embedding = torch.cat([torch.cos(args), torch.sin(args)], dim=-1)
if dim % 2:
embedding = torch.cat(
[embedding, torch.zeros_like(embedding[:, :1])], dim=-1
)
else:
embedding = repeat(timesteps, "b -> b d", d=dim)
return embedding
def normalization(channels): def normalization(channels):
""" """
Make a standard normalization layer. Make a standard normalization layer.
@@ -854,31 +502,3 @@ def zero_module(module):
for p in module.parameters(): for p in module.parameters():
p.detach().zero_() p.detach().zero_()
return module return module
# feedforward
class GEGLU(nn.Module):
def __init__(self, dim_in, dim_out):
super().__init__()
self.proj = nn.Linear(dim_in, dim_out * 2)
def forward(self, x):
x, gate = self.proj(x).chunk(2, dim=-1)
return x * nn.functional.gelu(gate)
class FeedForward(nn.Module):
def __init__(self, dim, dim_out=None, mult=4, glu=False, dropout=0.0):
super().__init__()
inner_dim = int(dim * mult)
dim_out = dim_out or dim
project_in = (
nn.Sequential(nn.Linear(dim, inner_dim), nn.GELU())
if not glu
else GEGLU(dim, inner_dim)
)
self.net = nn.Sequential(
project_in, nn.Dropout(dropout), nn.Linear(inner_dim, dim_out)
)
def forward(self, x):
return self.net(x)