Merge pull request huggingface#46 from huggingface/merge_ldm_resnet

[ResNet Refactor] Merge ldm into resnet

Author: patrickvonplaten

models/resnet.py

@@ -162,7 +162,7 @@ def forward(self, x):
 
 # RESNETS
 
-# unet_glide.py & unet_ldm.py
+# unet_glide.py
 class ResBlock(TimestepBlock):
     """
     A residual block that can optionally change the number of channels.
@@ -188,6 +188,7 @@ def __init__(
         use_checkpoint=False,
         up=False,
         down=False,
+        overwrite=False,  # TODO(Patrick) - use for glide at later stage
     ):
         super().__init__()
         self.channels = channels
@@ -236,13 +237,76 @@ def __init__(
         else:
             self.skip_connection = conv_nd(dims, channels, self.out_channels, 1)
 
+        self.overwrite = overwrite
+        self.is_overwritten = False
+        if self.overwrite:
+            in_channels = channels
+            out_channels = self.out_channels
+            conv_shortcut = False
+            dropout = 0.0
+            temb_channels = emb_channels
+            groups = 32
+            pre_norm = True
+            eps = 1e-5
+            non_linearity = "silu"
+            self.pre_norm = pre_norm
+            self.in_channels = in_channels
+            out_channels = in_channels if out_channels is None else out_channels
+            self.out_channels = out_channels
+            self.use_conv_shortcut = conv_shortcut
+
+            if self.pre_norm:
+                self.norm1 = Normalize(in_channels, num_groups=groups, eps=eps)
+            else:
+                self.norm1 = Normalize(out_channels, num_groups=groups, eps=eps)
+
+            self.conv1 = torch.nn.Conv2d(in_channels, out_channels, kernel_size=3, stride=1, padding=1)
+            self.temb_proj = torch.nn.Linear(temb_channels, out_channels)
+            self.norm2 = Normalize(out_channels, num_groups=groups, eps=eps)
+            self.dropout = torch.nn.Dropout(dropout)
+            self.conv2 = torch.nn.Conv2d(out_channels, out_channels, kernel_size=3, stride=1, padding=1)
+            if non_linearity == "swish":
+                self.nonlinearity = nonlinearity
+            elif non_linearity == "mish":
+                self.nonlinearity = Mish()
+            elif non_linearity == "silu":
+                self.nonlinearity = nn.SiLU()
+
+            if self.in_channels != self.out_channels:
+                self.nin_shortcut = torch.nn.Conv2d(in_channels, out_channels, kernel_size=1, stride=1, padding=0)
+
+    def set_weights(self):
+        # TODO(Patrick): use for glide at later stage
+        self.norm1.weight.data = self.in_layers[0].weight.data
+        self.norm1.bias.data = self.in_layers[0].bias.data
+
+        self.conv1.weight.data = self.in_layers[-1].weight.data
+        self.conv1.bias.data = self.in_layers[-1].bias.data
+
+        self.temb_proj.weight.data = self.emb_layers[-1].weight.data
+        self.temb_proj.bias.data = self.emb_layers[-1].bias.data
+
+        self.norm2.weight.data = self.out_layers[0].weight.data
+        self.norm2.bias.data = self.out_layers[0].bias.data
+
+        self.conv2.weight.data = self.out_layers[-1].weight.data
+        self.conv2.bias.data = self.out_layers[-1].bias.data
+
+        if self.in_channels != self.out_channels:
+            self.nin_shortcut.weight.data = self.skip_connection.weight.data
+            self.nin_shortcut.bias.data = self.skip_connection.bias.data
+
     def forward(self, x, emb):
         """
         Apply the block to a Tensor, conditioned on a timestep embedding.
 
         :param x: an [N x C x ...] Tensor of features. :param emb: an [N x emb_channels] Tensor of timestep embeddings.
         :return: an [N x C x ...] Tensor of outputs.
         """
+        if self.overwrite:
+            # TODO(Patrick): use for glide at later stage
+            self.set_weights()
+
         if self.updown:
             in_rest, in_conv = self.in_layers[:-1], self.in_layers[-1]
             h = in_rest(x)
@@ -251,6 +315,7 @@ def forward(self, x, emb):
             h = in_conv(h)
         else:
             h = self.in_layers(x)
+
         emb_out = self.emb_layers(emb).type(h.dtype)
         while len(emb_out.shape) < len(h.shape):
             emb_out = emb_out[..., None]
@@ -262,7 +327,50 @@ def forward(self, x, emb):
         else:
             h = h + emb_out
             h = self.out_layers(h)
-        return self.skip_connection(x) + h
+
+        result = self.skip_connection(x) + h
+
+        # TODO(Patrick) Use for glide at later stage
+        #        result = self.forward_2(x, emb)
+
+        return result
+
+    def forward_2(self, x, temb, mask=1.0):
+        if self.overwrite and not self.is_overwritten:
+            self.set_weights()
+            self.is_overwritten = True
+
+        h = x
+        if self.pre_norm:
+            h = self.norm1(h)
+            h = self.nonlinearity(h)
+
+        h = self.conv1(h)
+
+        if not self.pre_norm:
+            h = self.norm1(h)
+            h = self.nonlinearity(h)
+
+        h = h + self.temb_proj(self.nonlinearity(temb))[:, :, None, None]
+
+        if self.pre_norm:
+            h = self.norm2(h)
+            h = self.nonlinearity(h)
+
+        h = self.dropout(h)
+        h = self.conv2(h)
+
+        if not self.pre_norm:
+            h = self.norm2(h)
+            h = self.nonlinearity(h)
+
+        if self.in_channels != self.out_channels:
+            if self.use_conv_shortcut:
+                x = self.conv_shortcut(x)
+            else:
+                x = self.nin_shortcut(x)
+
+        return x + h
 
 
 # unet.py and unet_grad_tts.py
@@ -280,6 +388,7 @@ def __init__(
         eps=1e-6,
         non_linearity="swish",
         overwrite_for_grad_tts=False,
+        overwrite_for_ldm=False,
     ):
         super().__init__()
         self.pre_norm = pre_norm
@@ -302,15 +411,19 @@ def __init__(
             self.nonlinearity = nonlinearity
         elif non_linearity == "mish":
             self.nonlinearity = Mish()
+        elif non_linearity == "silu":
+            self.nonlinearity = nn.SiLU()
 
         if self.in_channels != self.out_channels:
             if self.use_conv_shortcut:
+                # TODO(Patrick) - this branch is never used I think => can be deleted!
                 self.conv_shortcut = torch.nn.Conv2d(in_channels, out_channels, kernel_size=3, stride=1, padding=1)
             else:
                 self.nin_shortcut = torch.nn.Conv2d(in_channels, out_channels, kernel_size=1, stride=1, padding=0)
 
         self.is_overwritten = False
         self.overwrite_for_grad_tts = overwrite_for_grad_tts
+        self.overwrite_for_ldm = overwrite_for_ldm
         if self.overwrite_for_grad_tts:
             dim = in_channels
             dim_out = out_channels
@@ -324,6 +437,39 @@ def __init__(
                 self.res_conv = torch.nn.Conv2d(dim, dim_out, 1)
             else:
                 self.res_conv = torch.nn.Identity()
+        elif self.overwrite_for_ldm:
+            dims = 2
+            #            eps = 1e-5
+            #            non_linearity = "silu"
+            #            overwrite_for_ldm
+            channels = in_channels
+            emb_channels = temb_channels
+            use_scale_shift_norm = False
+
+            self.in_layers = nn.Sequential(
+                normalization(channels, swish=1.0),
+                nn.Identity(),
+                conv_nd(dims, channels, self.out_channels, 3, padding=1),
+            )
+            self.emb_layers = nn.Sequential(
+                nn.SiLU(),
+                linear(
+                    emb_channels,
+                    2 * self.out_channels if use_scale_shift_norm else self.out_channels,
+                ),
+            )
+            self.out_layers = nn.Sequential(
+                normalization(self.out_channels, swish=0.0 if use_scale_shift_norm else 1.0),
+                nn.SiLU() if use_scale_shift_norm else nn.Identity(),
+                nn.Dropout(p=dropout),
+                zero_module(conv_nd(dims, self.out_channels, self.out_channels, 3, padding=1)),
+            )
+            if self.out_channels == in_channels:
+                self.skip_connection = nn.Identity()
+            #            elif use_conv:
+            #                self.skip_connection = conv_nd(dims, channels, self.out_channels, 3, padding=1)
+            else:
+                self.skip_connection = conv_nd(dims, channels, self.out_channels, 1)
 
     def set_weights_grad_tts(self):
         self.conv1.weight.data = self.block1.block[0].weight.data
@@ -343,13 +489,36 @@ def set_weights_grad_tts(self):
             self.nin_shortcut.weight.data = self.res_conv.weight.data
             self.nin_shortcut.bias.data = self.res_conv.bias.data
 
-    def forward(self, x, temb, mask=None):
+    def set_weights_ldm(self):
+        self.norm1.weight.data = self.in_layers[0].weight.data
+        self.norm1.bias.data = self.in_layers[0].bias.data
+
+        self.conv1.weight.data = self.in_layers[-1].weight.data
+        self.conv1.bias.data = self.in_layers[-1].bias.data
+
+        self.temb_proj.weight.data = self.emb_layers[-1].weight.data
+        self.temb_proj.bias.data = self.emb_layers[-1].bias.data
+
+        self.norm2.weight.data = self.out_layers[0].weight.data
+        self.norm2.bias.data = self.out_layers[0].bias.data
+
+        self.conv2.weight.data = self.out_layers[-1].weight.data
+        self.conv2.bias.data = self.out_layers[-1].bias.data
+
+        if self.in_channels != self.out_channels:
+            self.nin_shortcut.weight.data = self.skip_connection.weight.data
+            self.nin_shortcut.bias.data = self.skip_connection.bias.data
+
+    def forward(self, x, temb, mask=1.0):
         if self.overwrite_for_grad_tts and not self.is_overwritten:
             self.set_weights_grad_tts()
             self.is_overwritten = True
+        elif self.overwrite_for_ldm and not self.is_overwritten:
+            self.set_weights_ldm()
+            self.is_overwritten = True
 
         h = x
-        h = h * mask if mask is not None else h
+        h = h * mask
         if self.pre_norm:
             h = self.norm1(h)
             h = self.nonlinearity(h)
@@ -359,11 +528,11 @@ def forward(self, x, temb, mask=None):
         if not self.pre_norm:
             h = self.norm1(h)
             h = self.nonlinearity(h)
-        h = h * mask if mask is not None else h
+        h = h * mask
 
         h = h + self.temb_proj(self.nonlinearity(temb))[:, :, None, None]
 
-        h = h * mask if mask is not None else h
+        h = h * mask
         if self.pre_norm:
             h = self.norm2(h)
             h = self.nonlinearity(h)
@@ -374,9 +543,9 @@ def forward(self, x, temb, mask=None):
         if not self.pre_norm:
             h = self.norm2(h)
             h = self.nonlinearity(h)
-        h = h * mask if mask is not None else h
+        h = h * mask
 
-        x = x * mask if mask is not None else x
+        x = x * mask
         if self.in_channels != self.out_channels:
             if self.use_conv_shortcut:
                 x = self.conv_shortcut(x)