remove convnext blocks, they are illsuited for generative work, validated by early experimental results at https://github.com/lucidrains/video-diffusion-pytorch

dalle2_pytorch/vqgan_vae.py

@@ -331,112 +331,6 @@ class ResBlock(nn.Module):
     def forward(self, x):
         return self.net(x) + x
 
-# convnext enc dec
-
-class ChanLayerNorm(nn.Module):
-    def __init__(self, dim, eps = 1e-5):
-        super().__init__()
-        self.eps = eps
-        self.g = nn.Parameter(torch.ones(1, dim, 1, 1))
-
-    def forward(self, x):
-        var = torch.var(x, dim = 1, unbiased = False, keepdim = True)
-        mean = torch.mean(x, dim = 1, keepdim = True)
-        return (x - mean) / (var + self.eps).sqrt() * self.g
-
-class ConvNext(nn.Module):
-    def __init__(self, dim, mult = 4, kernel_size = 3, ds_kernel_size = 7):
-        super().__init__()
-        inner_dim = int(dim * mult)
-        self.net = nn.Sequential(
-            nn.Conv2d(dim, dim, ds_kernel_size, padding = ds_kernel_size // 2, groups = dim),
-            ChanLayerNorm(dim),
-            nn.Conv2d(dim, inner_dim, kernel_size, padding = kernel_size // 2),
-            nn.GELU(),
-            nn.Conv2d(inner_dim, dim, kernel_size, padding = kernel_size // 2)
-        )
-
-    def forward(self, x):
-        return self.net(x) + x
-
-class ConvNextEncDec(nn.Module):
-    def __init__(
-        self,
-        dim,
-        *,
-        channels = 3,
-        layers = 4,
-        layer_mults = None,
-        num_blocks = 1,
-        first_conv_kernel_size = 5,
-        use_attn = True,
-        attn_dim_head = 64,
-        attn_heads = 8,
-        attn_dropout = 0.,
-    ):
-        super().__init__()
-
-        self.layers = layers
-
-        self.encoders = MList([])
-        self.decoders = MList([])
-
-        layer_mults = default(layer_mults, list(map(lambda t: 2 ** t, range(layers))))
-        assert len(layer_mults) == layers, 'layer multipliers must be equal to designated number of layers'
-
-        layer_dims = [dim * mult for mult in layer_mults]
-        dims = (dim, *layer_dims)
-
-        self.encoded_dim = dims[-1]
-
-        dim_pairs = zip(dims[:-1], dims[1:])
-
-        append = lambda arr, t: arr.append(t)
-        prepend = lambda arr, t: arr.insert(0, t)
-
-        if not isinstance(num_blocks, tuple):
-            num_blocks = (*((0,) * (layers - 1)), num_blocks)
-
-        if not isinstance(use_attn, tuple):
-            use_attn = (*((False,) * (layers - 1)), use_attn)
-
-        assert len(num_blocks) == layers, 'number of blocks config must be equal to number of layers'
-        assert len(use_attn) == layers
-
-        for layer_index, (dim_in, dim_out), layer_num_blocks, layer_use_attn in zip(range(layers), dim_pairs, num_blocks, use_attn):
-            append(self.encoders, nn.Sequential(nn.Conv2d(dim_in, dim_out, 4, stride = 2, padding = 1), leaky_relu()))
-            prepend(self.decoders, nn.Sequential(nn.ConvTranspose2d(dim_out, dim_in, 4, 2, 1), leaky_relu()))
-
-            if layer_use_attn:
-                prepend(self.decoders, VQGanAttention(dim = dim_out, heads = attn_heads, dim_head = attn_dim_head, dropout = attn_dropout))
-
-            for _ in range(layer_num_blocks):
-                append(self.encoders, ConvNext(dim_out))
-                prepend(self.decoders, ConvNext(dim_out))
-
-            if layer_use_attn:
-                append(self.encoders, VQGanAttention(dim = dim_out, heads = attn_heads, dim_head = attn_dim_head, dropout = attn_dropout))
-
-        prepend(self.encoders, nn.Conv2d(channels, dim, first_conv_kernel_size, padding = first_conv_kernel_size // 2))
-        append(self.decoders, nn.Conv2d(dim, channels, 1))
-
-    def get_encoded_fmap_size(self, image_size):
-        return image_size // (2 ** self.layers)
-
-    @property
-    def last_dec_layer(self):
-        return self.decoders[-1].weight
-
-    def encode(self, x):
-        for enc in self.encoders:
-            x = enc(x)
-        return x
-
-    def decode(self, x):
-        for dec in self.decoders:
-            x = dec(x)
-        return x
-
 # vqgan attention layer
 
 class VQGanAttention(nn.Module):
@@ -682,8 +576,6 @@ class VQGanVAE(nn.Module):
             enc_dec_klass = ResnetEncDec
         elif vae_type == 'vit':
             enc_dec_klass = ViTEncDec
-        elif vae_type == 'convnext':
-            enc_dec_klass = ConvNextEncDec
         else:
             raise ValueError(f'{vae_type} not valid')