Merge remote-tracking branch 'origin/main'

README.md

@@ -166,13 +166,14 @@ image_pil.save("test.png")
 
 #### **Text to Image generation with Latent Diffusion**
 
+_Note: To use latent diffusion install transformers from [this branch](https://github.com/patil-suraj/transformers/tree/ldm-bert)._
+
 ```python
 from diffusers import DiffusionPipeline
 
 ldm = DiffusionPipeline.from_pretrained("fusing/latent-diffusion-text2im-large")
 
-generator = torch.Generator()
-generator = generator.manual_seed(6694729458485568)
+generator = torch.manual_seed(42)
 
 prompt = "A painting of a squirrel eating a burger"
 image = ldm([prompt], generator=generator, eta=0.3, guidance_scale=6.0, num_inference_steps=50)
@@ -197,7 +198,7 @@ from diffusers import BDDM, DiffusionPipeline
 torch_device = "cuda"
 
 # load the BDDM pipeline
-bddm = DiffusionPipeline.from_pretrained("fusing/diffwave-vocoder")
+bddm = DiffusionPipeline.from_pretrained("fusing/diffwave-vocoder-ljspeech")
 
 # load tacotron2 to get the mel spectograms
 tacotron2 = torch.hub.load('NVIDIA/DeepLearningExamples:torchhub', 'nvidia_tacotron2', model_math='fp16')

src/diffusers/__init__.py

@@ -8,6 +8,7 @@ from .modeling_utils import ModelMixin
 from .models.unet import UNetModel
 from .models.unet_glide import GLIDEUNetModel, GLIDESuperResUNetModel, GLIDETextToImageUNetModel
 from .models.unet_ldm import UNetLDMModel
+from .models.unet_grad_tts import UNetGradTTSModel
 from .pipeline_utils import DiffusionPipeline
 from .pipelines import DDIM, DDPM, GLIDE, LatentDiffusion, PNDM, BDDM
 from .schedulers import DDIMScheduler, DDPMScheduler, SchedulerMixin, PNDMScheduler

src/diffusers/models/__init__.py

@@ -19,3 +19,4 @@
 from .unet import UNetModel
 from .unet_glide import GLIDEUNetModel, GLIDESuperResUNetModel, GLIDETextToImageUNetModel
 from .unet_ldm import UNetLDMModel
+from .unet_grad_tts import UNetGradTTSModel
\ No newline at end of file

src/diffusers/models/unet_grad_tts.py

+import math
+
+import torch
+
+try:
+    from einops import rearrange, repeat
+except:
+    print("Einops is not installed")
+    pass
+
+from ..configuration_utils import ConfigMixin
+from ..modeling_utils import ModelMixin
+
+class Mish(torch.nn.Module):
+    def forward(self, x):
+        return x * torch.tanh(torch.nn.functional.softplus(x))
+
+
+class Upsample(torch.nn.Module):
+    def __init__(self, dim):
+        super(Upsample, self).__init__()
+        self.conv = torch.nn.ConvTranspose2d(dim, dim, 4, 2, 1)
+
+    def forward(self, x):
+        return self.conv(x)
+
+
+class Downsample(torch.nn.Module):
+    def __init__(self, dim):
+        super(Downsample, self).__init__()
+        self.conv = torch.nn.Conv2d(dim, dim, 3, 2, 1)
+
+    def forward(self, x):
+        return self.conv(x)
+
+
+class Rezero(torch.nn.Module):
+    def __init__(self, fn):
+        super(Rezero, self).__init__()
+        self.fn = fn
+        self.g = torch.nn.Parameter(torch.zeros(1))
+
+    def forward(self, x):
+        return self.fn(x) * self.g
+
+
+class Block(torch.nn.Module):
+    def __init__(self, dim, dim_out, groups=8):
+        super(Block, self).__init__()
+        self.block = torch.nn.Sequential(torch.nn.Conv2d(dim, dim_out, 3, 
+                                         padding=1), torch.nn.GroupNorm(
+                                         groups, dim_out), Mish())
+
+    def forward(self, x, mask):
+        output = self.block(x * mask)
+        return output * mask
+
+
+class ResnetBlock(torch.nn.Module):
+    def __init__(self, dim, dim_out, time_emb_dim, groups=8):
+        super(ResnetBlock, self).__init__()
+        self.mlp = torch.nn.Sequential(Mish(), torch.nn.Linear(time_emb_dim, 
+                                                               dim_out))
+
+        self.block1 = Block(dim, dim_out, groups=groups)
+        self.block2 = Block(dim_out, dim_out, groups=groups)
+        if dim != dim_out:
+            self.res_conv = torch.nn.Conv2d(dim, dim_out, 1)
+        else:
+            self.res_conv = torch.nn.Identity()
+
+    def forward(self, x, mask, time_emb):
+        h = self.block1(x, mask)
+        h += self.mlp(time_emb).unsqueeze(-1).unsqueeze(-1)
+        h = self.block2(h, mask)
+        output = h + self.res_conv(x * mask)
+        return output
+
+
+class LinearAttention(torch.nn.Module):
+    def __init__(self, dim, heads=4, dim_head=32):
+        super(LinearAttention, self).__init__()
+        self.heads = heads
+        hidden_dim = dim_head * heads
+        self.to_qkv = torch.nn.Conv2d(dim, hidden_dim * 3, 1, bias=False)
+        self.to_out = torch.nn.Conv2d(hidden_dim, dim, 1)            
+
+    def forward(self, x):
+        b, c, h, w = x.shape
+        qkv = self.to_qkv(x)
+        q, k, v = rearrange(qkv, 'b (qkv heads c) h w -> qkv b heads c (h w)', 
+                            heads = self.heads, qkv=3)            
+        k = k.softmax(dim=-1)
+        context = torch.einsum('bhdn,bhen->bhde', k, v)
+        out = torch.einsum('bhde,bhdn->bhen', context, q)
+        out = rearrange(out, 'b heads c (h w) -> b (heads c) h w', 
+                        heads=self.heads, h=h, w=w)
+        return self.to_out(out)
+
+
+class Residual(torch.nn.Module):
+    def __init__(self, fn):
+        super(Residual, self).__init__()
+        self.fn = fn
+
+    def forward(self, x, *args, **kwargs):
+        output = self.fn(x, *args, **kwargs) + x
+        return output
+
+
+class SinusoidalPosEmb(torch.nn.Module):
+    def __init__(self, dim):
+        super(SinusoidalPosEmb, self).__init__()
+        self.dim = dim
+
+    def forward(self, x, scale=1000):
+        device = x.device
+        half_dim = self.dim // 2
+        emb = math.log(10000) / (half_dim - 1)
+        emb = torch.exp(torch.arange(half_dim, device=device).float() * -emb)
+        emb = scale * x.unsqueeze(1) * emb.unsqueeze(0)
+        emb = torch.cat((emb.sin(), emb.cos()), dim=-1)
+        return emb
+
+
+class UNetGradTTSModel(ModelMixin, ConfigMixin):
+    def __init__(
+        self,
+        dim,
+        dim_mults=(1, 2, 4),
+        groups=8,
+        n_spks=None,
+        spk_emb_dim=64,
+        n_feats=80,
+        pe_scale=1000
+    ):
+        super(UNetGradTTSModel, self).__init__()
+
+        self.register(
+            dim=dim,
+            dim_mults=dim_mults,
+            groups=groups,
+            n_spks=n_spks,
+            spk_emb_dim=spk_emb_dim,
+            n_feats=n_feats,
+            pe_scale=pe_scale
+        )
+        
+        self.dim = dim
+        self.dim_mults = dim_mults
+        self.groups = groups
+        self.n_spks = n_spks if not isinstance(n_spks, type(None)) else 1
+        self.spk_emb_dim = spk_emb_dim
+        self.pe_scale = pe_scale
+        
+        if n_spks > 1:
+            self.spk_mlp = torch.nn.Sequential(torch.nn.Linear(spk_emb_dim, spk_emb_dim * 4), Mish(),
+                                               torch.nn.Linear(spk_emb_dim * 4, n_feats))
+        self.time_pos_emb = SinusoidalPosEmb(dim)
+        self.mlp = torch.nn.Sequential(torch.nn.Linear(dim, dim * 4), Mish(),
+                                       torch.nn.Linear(dim * 4, dim))
+
+        dims = [2 + (1 if n_spks > 1 else 0), *map(lambda m: dim * m, dim_mults)]
+        in_out = list(zip(dims[:-1], dims[1:]))
+        self.downs = torch.nn.ModuleList([])
+        self.ups = torch.nn.ModuleList([])
+        num_resolutions = len(in_out)
+
+        for ind, (dim_in, dim_out) in enumerate(in_out):
+            is_last = ind >= (num_resolutions - 1)
+            self.downs.append(torch.nn.ModuleList([
+                       ResnetBlock(dim_in, dim_out, time_emb_dim=dim),
+                       ResnetBlock(dim_out, dim_out, time_emb_dim=dim),
+                       Residual(Rezero(LinearAttention(dim_out))),
+                       Downsample(dim_out) if not is_last else torch.nn.Identity()]))
+
+        mid_dim = dims[-1]
+        self.mid_block1 = ResnetBlock(mid_dim, mid_dim, time_emb_dim=dim)
+        self.mid_attn = Residual(Rezero(LinearAttention(mid_dim)))
+        self.mid_block2 = ResnetBlock(mid_dim, mid_dim, time_emb_dim=dim)
+
+        for ind, (dim_in, dim_out) in enumerate(reversed(in_out[1:])):
+            self.ups.append(torch.nn.ModuleList([
+                     ResnetBlock(dim_out * 2, dim_in, time_emb_dim=dim),
+                     ResnetBlock(dim_in, dim_in, time_emb_dim=dim),
+                     Residual(Rezero(LinearAttention(dim_in))),
+                     Upsample(dim_in)]))
+        self.final_block = Block(dim, dim)
+        self.final_conv = torch.nn.Conv2d(dim, 1, 1)
+
+    def forward(self, x, mask, mu, t, spk=None):
+        if not isinstance(spk, type(None)):
+            s = self.spk_mlp(spk)
+        
+        t = self.time_pos_emb(t, scale=self.pe_scale)
+        t = self.mlp(t)
+
+        if self.n_spks < 2:
+            x = torch.stack([mu, x], 1)
+        else:
+            s = s.unsqueeze(-1).repeat(1, 1, x.shape[-1])
+            x = torch.stack([mu, x, s], 1)
+        mask = mask.unsqueeze(1)
+
+        hiddens = []
+        masks = [mask]
+        for resnet1, resnet2, attn, downsample in self.downs:
+            mask_down = masks[-1]
+            x = resnet1(x, mask_down, t)
+            x = resnet2(x, mask_down, t)
+            x = attn(x)
+            hiddens.append(x)
+            x = downsample(x * mask_down)
+            masks.append(mask_down[:, :, :, ::2])
+
+        masks = masks[:-1]
+        mask_mid = masks[-1]
+        x = self.mid_block1(x, mask_mid, t)
+        x = self.mid_attn(x)
+        x = self.mid_block2(x, mask_mid, t)
+
+        for resnet1, resnet2, attn, upsample in self.ups:
+            mask_up = masks.pop()
+            x = torch.cat((x, hiddens.pop()), dim=1)
+            x = resnet1(x, mask_up, t)
+            x = resnet2(x, mask_up, t)
+            x = attn(x)
+            x = upsample(x * mask_up)
+
+        x = self.final_block(x, mask)
+        output = self.final_conv(x * mask)
+
+        return (output * mask).squeeze(1)
\ No newline at end of file

src/diffusers/pipelines/configuration_ldmbert.py

-# coding=utf-8
-# Copyright 2022 The Fairseq Authors and The HuggingFace Inc. team. All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-""" LDMBERT model configuration"""
-
-from transformers.configuration_utils import PretrainedConfig
-from transformers.utils import logging
-
-
-logger = logging.get_logger(__name__)
-
-LDMBERT_PRETRAINED_CONFIG_ARCHIVE_MAP = {
-    "ldm-bert": "https://huggingface.co/ldm-bert/resolve/main/config.json",
-}
-
-
-class LDMBertConfig(PretrainedConfig):
-    r"""
-    This is the configuration class to store the configuration of a [`LDMBertModel`]. It is used to instantiate a
-    LDMBERT model according to the specified arguments, defining the model architecture. Instantiating a configuration
-    with the defaults will yield a similar configuration to that of the LDMBERT
-    [facebook/ldmbert-large](https://huggingface.co/facebook/ldmbert-large) architecture.
-
-    Configuration objects inherit from [`PretrainedConfig`] and can be used to control the model outputs. Read the
-    documentation from [`PretrainedConfig`] for more information.
-
-
-    Args:
-        vocab_size (`int`, *optional*, defaults to 50265):
-            Vocabulary size of the LDMBERT model. Defines the number of different tokens that can be represented by the
-            `inputs_ids` passed when calling [`LDMBertModel`] or [`TFLDMBertModel`].
-        d_model (`int`, *optional*, defaults to 1024):
-            Dimensionality of the layers and the pooler layer.
-        encoder_layers (`int`, *optional*, defaults to 12):
-            Number of encoder layers.
-        decoder_layers (`int`, *optional*, defaults to 12):
-            Number of decoder layers.
-        encoder_attention_heads (`int`, *optional*, defaults to 16):
-            Number of attention heads for each attention layer in the Transformer encoder.
-        decoder_attention_heads (`int`, *optional*, defaults to 16):
-            Number of attention heads for each attention layer in the Transformer decoder.
-        decoder_ffn_dim (`int`, *optional*, defaults to 4096):
-            Dimensionality of the "intermediate" (often named feed-forward) layer in decoder.
-        encoder_ffn_dim (`int`, *optional*, defaults to 4096):
-            Dimensionality of the "intermediate" (often named feed-forward) layer in decoder.
-        activation_function (`str` or `function`, *optional*, defaults to `"gelu"`):
-            The non-linear activation function (function or string) in the encoder and pooler. If string, `"gelu"`,
-            `"relu"`, `"silu"` and `"gelu_new"` are supported.
-        dropout (`float`, *optional*, defaults to 0.1):
-            The dropout probability for all fully connected layers in the embeddings, encoder, and pooler.
-        attention_dropout (`float`, *optional*, defaults to 0.0):
-            The dropout ratio for the attention probabilities.
-        activation_dropout (`float`, *optional*, defaults to 0.0):
-            The dropout ratio for activations inside the fully connected layer.
-        classifier_dropout (`float`, *optional*, defaults to 0.0):
-            The dropout ratio for classifier.
-        max_position_embeddings (`int`, *optional*, defaults to 1024):
-            The maximum sequence length that this model might ever be used with. Typically set this to something large
-            just in case (e.g., 512 or 1024 or 2048).
-        init_std (`float`, *optional*, defaults to 0.02):
-            The standard deviation of the truncated_normal_initializer for initializing all weight matrices.
-        encoder_layerdrop: (`float`, *optional*, defaults to 0.0):
-            The LayerDrop probability for the encoder. See the [LayerDrop paper](see https://arxiv.org/abs/1909.11556)
-            for more details.
-        decoder_layerdrop: (`float`, *optional*, defaults to 0.0):
-            The LayerDrop probability for the decoder. See the [LayerDrop paper](see https://arxiv.org/abs/1909.11556)
-            for more details.
-        scale_embedding (`bool`, *optional*, defaults to `False`):
-            Scale embeddings by diving by sqrt(d_model).
-        use_cache (`bool`, *optional*, defaults to `True`):
-            Whether or not the model should return the last key/values attentions (not used by all models).
-        num_labels: (`int`, *optional*, defaults to 3):
-            The number of labels to use in [`LDMBertForSequenceClassification`].
-        forced_eos_token_id (`int`, *optional*, defaults to 2):
-            The id of the token to force as the last generated token when `max_length` is reached. Usually set to
-            `eos_token_id`.
-
-    Example:
-
-    ```python
-    >>> from transformers import LDMBertModel, LDMBertConfig
-
-    >>> # Initializing a LDMBERT facebook/ldmbert-large style configuration
-    >>> configuration = LDMBertConfig()
-
-    >>> # Initializing a model from the facebook/ldmbert-large style configuration
-    >>> model = LDMBertModel(configuration)
-
-    >>> # Accessing the model configuration
-    >>> configuration = model.config
-    ```"""
-    model_type = "ldmbert"
-    keys_to_ignore_at_inference = ["past_key_values"]
-    attribute_map = {"num_attention_heads": "encoder_attention_heads", "hidden_size": "d_model"}
-
-    def __init__(
-        self,
-        vocab_size=30522,
-        max_position_embeddings=77,
-        encoder_layers=32,
-        encoder_ffn_dim=5120,
-        encoder_attention_heads=8,
-        head_dim=64,
-        encoder_layerdrop=0.0,
-        activation_function="gelu",
-        d_model=1280,
-        dropout=0.1,
-        attention_dropout=0.0,
-        activation_dropout=0.0,
-        init_std=0.02,
-        classifier_dropout=0.0,
-        scale_embedding=False,
-        use_cache=True,
-        pad_token_id=0,
-        **kwargs,
-    ):
-        self.vocab_size = vocab_size
-        self.max_position_embeddings = max_position_embeddings
-        self.d_model = d_model
-        self.encoder_ffn_dim = encoder_ffn_dim
-        self.encoder_layers = encoder_layers
-        self.encoder_attention_heads = encoder_attention_heads
-        self.head_dim = head_dim
-        self.dropout = dropout
-        self.attention_dropout = attention_dropout
-        self.activation_dropout = activation_dropout
-        self.activation_function = activation_function
-        self.init_std = init_std
-        self.encoder_layerdrop = encoder_layerdrop
-        self.classifier_dropout = classifier_dropout
-        self.use_cache = use_cache
-        self.num_hidden_layers = encoder_layers
-        self.scale_embedding = scale_embedding  # scale factor will be sqrt(d_model) if True
-
-        super().__init__(pad_token_id=pad_token_id, **kwargs)

src/diffusers/pipelines/pipeline_grad_tts.py

+""" from https://github.com/jaywalnut310/glow-tts """
+
+import math
+
+import torch
+from torch import nn
+
+from diffusers.configuration_utils import ConfigMixin
+from diffusers.modeling_utils import ModelMixin
+
+
+def sequence_mask(length, max_length=None):
+    if max_length is None:
+        max_length = length.max()
+    x = torch.arange(int(max_length), dtype=length.dtype, device=length.device)
+    return x.unsqueeze(0) < length.unsqueeze(1)
+
+
+def fix_len_compatibility(length, num_downsamplings_in_unet=2):
+    while True:
+        if length % (2**num_downsamplings_in_unet) == 0:
+            return length
+        length += 1
+
+
+def convert_pad_shape(pad_shape):
+    l = pad_shape[::-1]
+    pad_shape = [item for sublist in l for item in sublist]
+    return pad_shape
+
+
+def generate_path(duration, mask):
+    device = duration.device
+
+    b, t_x, t_y = mask.shape
+    cum_duration = torch.cumsum(duration, 1)
+    path = torch.zeros(b, t_x, t_y, dtype=mask.dtype).to(device=device)
+
+    cum_duration_flat = cum_duration.view(b * t_x)
+    path = sequence_mask(cum_duration_flat, t_y).to(mask.dtype)
+    path = path.view(b, t_x, t_y)
+    path = path - torch.nn.functional.pad(path, convert_pad_shape([[0, 0], 
+                                          [1, 0], [0, 0]]))[:, :-1]
+    path = path * mask
+    return path
+
+
+def duration_loss(logw, logw_, lengths):
+    loss = torch.sum((logw - logw_)**2) / torch.sum(lengths)
+    return loss
+
+
+class LayerNorm(nn.Module):
+    def __init__(self, channels, eps=1e-4):
+        super(LayerNorm, self).__init__()
+        self.channels = channels
+        self.eps = eps
+
+        self.gamma = torch.nn.Parameter(torch.ones(channels))
+        self.beta = torch.nn.Parameter(torch.zeros(channels))
+
+    def forward(self, x):
+        n_dims = len(x.shape)
+        mean = torch.mean(x, 1, keepdim=True)
+        variance = torch.mean((x - mean)**2, 1, keepdim=True)
+
+        x = (x - mean) * torch.rsqrt(variance + self.eps)
+
+        shape = [1, -1] + [1] * (n_dims - 2)
+        x = x * self.gamma.view(*shape) + self.beta.view(*shape)
+        return x
+
+
+class ConvReluNorm(nn.Module):
+    def __init__(self, in_channels, hidden_channels, out_channels, kernel_size, 
+                 n_layers, p_dropout):
+        super(ConvReluNorm, self).__init__()
+        self.in_channels = in_channels
+        self.hidden_channels = hidden_channels
+        self.out_channels = out_channels
+        self.kernel_size = kernel_size
+        self.n_layers = n_layers
+        self.p_dropout = p_dropout
+
+        self.conv_layers = torch.nn.ModuleList()
+        self.norm_layers = torch.nn.ModuleList()
+        self.conv_layers.append(torch.nn.Conv1d(in_channels, hidden_channels, 
+                                                kernel_size, padding=kernel_size//2))
+        self.norm_layers.append(LayerNorm(hidden_channels))
+        self.relu_drop = torch.nn.Sequential(torch.nn.ReLU(), torch.nn.Dropout(p_dropout))
+        for _ in range(n_layers - 1):
+            self.conv_layers.append(torch.nn.Conv1d(hidden_channels, hidden_channels, 
+                                                    kernel_size, padding=kernel_size//2))
+            self.norm_layers.append(LayerNorm(hidden_channels))
+        self.proj = torch.nn.Conv1d(hidden_channels, out_channels, 1)
+        self.proj.weight.data.zero_()
+        self.proj.bias.data.zero_()
+
+    def forward(self, x, x_mask):
+        x_org = x
+        for i in range(self.n_layers):
+            x = self.conv_layers[i](x * x_mask)
+            x = self.norm_layers[i](x)
+            x = self.relu_drop(x)
+        x = x_org + self.proj(x)
+        return x * x_mask
+
+
+class DurationPredictor(nn.Module):
+    def __init__(self, in_channels, filter_channels, kernel_size, p_dropout):
+        super(DurationPredictor, self).__init__()
+        self.in_channels = in_channels
+        self.filter_channels = filter_channels
+        self.p_dropout = p_dropout
+
+        self.drop = torch.nn.Dropout(p_dropout)
+        self.conv_1 = torch.nn.Conv1d(in_channels, filter_channels, 
+                                      kernel_size, padding=kernel_size//2)
+        self.norm_1 = LayerNorm(filter_channels)
+        self.conv_2 = torch.nn.Conv1d(filter_channels, filter_channels, 
+                                      kernel_size, padding=kernel_size//2)
+        self.norm_2 = LayerNorm(filter_channels)
+        self.proj = torch.nn.Conv1d(filter_channels, 1, 1)
+
+    def forward(self, x, x_mask):
+        x = self.conv_1(x * x_mask)
+        x = torch.relu(x)
+        x = self.norm_1(x)
+        x = self.drop(x)
+        x = self.conv_2(x * x_mask)
+        x = torch.relu(x)
+        x = self.norm_2(x)
+        x = self.drop(x)
+        x = self.proj(x * x_mask)
+        return x * x_mask
+
+
+class MultiHeadAttention(nn.Module):
+    def __init__(self, channels, out_channels, n_heads, window_size=None, 
+                 heads_share=True, p_dropout=0.0, proximal_bias=False, 
+                 proximal_init=False):
+        super(MultiHeadAttention, self).__init__()
+        assert channels % n_heads == 0
+
+        self.channels = channels
+        self.out_channels = out_channels
+        self.n_heads = n_heads
+        self.window_size = window_size
+        self.heads_share = heads_share
+        self.proximal_bias = proximal_bias
+        self.p_dropout = p_dropout
+        self.attn = None
+
+        self.k_channels = channels // n_heads
+        self.conv_q = torch.nn.Conv1d(channels, channels, 1)
+        self.conv_k = torch.nn.Conv1d(channels, channels, 1)
+        self.conv_v = torch.nn.Conv1d(channels, channels, 1)
+        if window_size is not None:
+            n_heads_rel = 1 if heads_share else n_heads
+            rel_stddev = self.k_channels**-0.5
+            self.emb_rel_k = torch.nn.Parameter(torch.randn(n_heads_rel, 
+                             window_size * 2 + 1, self.k_channels) * rel_stddev)
+            self.emb_rel_v = torch.nn.Parameter(torch.randn(n_heads_rel, 
+                             window_size * 2 + 1, self.k_channels) * rel_stddev)
+        self.conv_o = torch.nn.Conv1d(channels, out_channels, 1)
+        self.drop = torch.nn.Dropout(p_dropout)
+
+        torch.nn.init.xavier_uniform_(self.conv_q.weight)
+        torch.nn.init.xavier_uniform_(self.conv_k.weight)
+        if proximal_init:
+            self.conv_k.weight.data.copy_(self.conv_q.weight.data)
+            self.conv_k.bias.data.copy_(self.conv_q.bias.data)
+        torch.nn.init.xavier_uniform_(self.conv_v.weight)
+        
+    def forward(self, x, c, attn_mask=None):
+        q = self.conv_q(x)
+        k = self.conv_k(c)
+        v = self.conv_v(c)
+        
+        x, self.attn = self.attention(q, k, v, mask=attn_mask)
+
+        x = self.conv_o(x)
+        return x
+
+    def attention(self, query, key, value, mask=None):
+        b, d, t_s, t_t = (*key.size(), query.size(2))
+        query = query.view(b, self.n_heads, self.k_channels, t_t).transpose(2, 3)
+        key = key.view(b, self.n_heads, self.k_channels, t_s).transpose(2, 3)
+        value = value.view(b, self.n_heads, self.k_channels, t_s).transpose(2, 3)
+
+        scores = torch.matmul(query, key.transpose(-2, -1)) / math.sqrt(self.k_channels)
+        if self.window_size is not None:
+            assert t_s == t_t, "Relative attention is only available for self-attention."
+            key_relative_embeddings = self._get_relative_embeddings(self.emb_rel_k, t_s)
+            rel_logits = self._matmul_with_relative_keys(query, key_relative_embeddings)
+            rel_logits = self._relative_position_to_absolute_position(rel_logits)
+            scores_local = rel_logits / math.sqrt(self.k_channels)
+            scores = scores + scores_local
+        if self.proximal_bias:
+            assert t_s == t_t, "Proximal bias is only available for self-attention."
+            scores = scores + self._attention_bias_proximal(t_s).to(device=scores.device, 
+                                                                    dtype=scores.dtype)
+        if mask is not None:
+            scores = scores.masked_fill(mask == 0, -1e4)
+        p_attn = torch.nn.functional.softmax(scores, dim=-1)
+        p_attn = self.drop(p_attn)
+        output = torch.matmul(p_attn, value)
+        if self.window_size is not None:
+            relative_weights = self._absolute_position_to_relative_position(p_attn)
+            value_relative_embeddings = self._get_relative_embeddings(self.emb_rel_v, t_s)
+            output = output + self._matmul_with_relative_values(relative_weights, 
+                                                                value_relative_embeddings)
+        output = output.transpose(2, 3).contiguous().view(b, d, t_t)
+        return output, p_attn
+
+    def _matmul_with_relative_values(self, x, y):
+        ret = torch.matmul(x, y.unsqueeze(0))
+        return ret
+
+    def _matmul_with_relative_keys(self, x, y):
+        ret = torch.matmul(x, y.unsqueeze(0).transpose(-2, -1))
+        return ret
+
+    def _get_relative_embeddings(self, relative_embeddings, length):
+        pad_length = max(length - (self.window_size + 1), 0)
+        slice_start_position = max((self.window_size + 1) - length, 0)
+        slice_end_position = slice_start_position + 2 * length - 1
+        if pad_length > 0:
+            padded_relative_embeddings = torch.nn.functional.pad(
+                            relative_embeddings, convert_pad_shape([[0, 0], 
+                            [pad_length, pad_length], [0, 0]]))
+        else:
+            padded_relative_embeddings = relative_embeddings
+        used_relative_embeddings = padded_relative_embeddings[:,
+                                   slice_start_position:slice_end_position]
+        return used_relative_embeddings
+
+    def _relative_position_to_absolute_position(self, x):
+        batch, heads, length, _ = x.size()
+        x = torch.nn.functional.pad(x, convert_pad_shape([[0,0],[0,0],[0,0],[0,1]]))
+        x_flat = x.view([batch, heads, length * 2 * length])
+        x_flat = torch.nn.functional.pad(x_flat, convert_pad_shape([[0,0],[0,0],[0,length-1]]))
+        x_final = x_flat.view([batch, heads, length+1, 2*length-1])[:, :, :length, length-1:]
+        return x_final
+
+    def _absolute_position_to_relative_position(self, x):
+        batch, heads, length, _ = x.size()
+        x = torch.nn.functional.pad(x, convert_pad_shape([[0, 0], [0, 0], [0, 0], [0, length-1]]))
+        x_flat = x.view([batch, heads, length**2 + length*(length - 1)])
+        x_flat = torch.nn.functional.pad(x_flat, convert_pad_shape([[0, 0], [0, 0], [length, 0]]))
+        x_final = x_flat.view([batch, heads, length, 2*length])[:,:,:,1:]
+        return x_final
+
+    def _attention_bias_proximal(self, length):
+        r = torch.arange(length, dtype=torch.float32)
+        diff = torch.unsqueeze(r, 0) - torch.unsqueeze(r, 1)
+        return torch.unsqueeze(torch.unsqueeze(-torch.log1p(torch.abs(diff)), 0), 0)
+
+
+class FFN(nn.Module):
+    def __init__(self, in_channels, out_channels, filter_channels, kernel_size, 
+                 p_dropout=0.0):
+        super(FFN, self).__init__()
+        self.in_channels = in_channels
+        self.out_channels = out_channels
+        self.filter_channels = filter_channels
+        self.kernel_size = kernel_size
+        self.p_dropout = p_dropout
+
+        self.conv_1 = torch.nn.Conv1d(in_channels, filter_channels, kernel_size, 
+                                      padding=kernel_size//2)
+        self.conv_2 = torch.nn.Conv1d(filter_channels, out_channels, kernel_size, 
+                                      padding=kernel_size//2)
+        self.drop = torch.nn.Dropout(p_dropout)
+
+    def forward(self, x, x_mask):
+        x = self.conv_1(x * x_mask)
+        x = torch.relu(x)
+        x = self.drop(x)
+        x = self.conv_2(x * x_mask)
+        return x * x_mask
+
+
+class Encoder(nn.Module):
+    def __init__(self, hidden_channels, filter_channels, n_heads, n_layers, 
+                 kernel_size=1, p_dropout=0.0, window_size=None, **kwargs):
+        super(Encoder, self).__init__()
+        self.hidden_channels = hidden_channels
+        self.filter_channels = filter_channels
+        self.n_heads = n_heads
+        self.n_layers = n_layers
+        self.kernel_size = kernel_size
+        self.p_dropout = p_dropout
+        self.window_size = window_size
+
+        self.drop = torch.nn.Dropout(p_dropout)
+        self.attn_layers = torch.nn.ModuleList()
+        self.norm_layers_1 = torch.nn.ModuleList()
+        self.ffn_layers = torch.nn.ModuleList()
+        self.norm_layers_2 = torch.nn.ModuleList()
+        for _ in range(self.n_layers):
+            self.attn_layers.append(MultiHeadAttention(hidden_channels, hidden_channels,
+                                    n_heads, window_size=window_size, p_dropout=p_dropout))
+            self.norm_layers_1.append(LayerNorm(hidden_channels))
+            self.ffn_layers.append(FFN(hidden_channels, hidden_channels,
+                                       filter_channels, kernel_size, p_dropout=p_dropout))
+            self.norm_layers_2.append(LayerNorm(hidden_channels))
+
+    def forward(self, x, x_mask):
+        attn_mask = x_mask.unsqueeze(2) * x_mask.unsqueeze(-1)
+        for i in range(self.n_layers):
+            x = x * x_mask
+            y = self.attn_layers[i](x, x, attn_mask)
+            y = self.drop(y)
+            x = self.norm_layers_1[i](x + y)
+            y = self.ffn_layers[i](x, x_mask)
+            y = self.drop(y)
+            x = self.norm_layers_2[i](x + y)
+        x = x * x_mask
+        return x
+
+
+class TextEncoder(ModelMixin, ConfigMixin):
+    def __init__(self, n_vocab, n_feats, n_channels, filter_channels, 
+                 filter_channels_dp, n_heads, n_layers, kernel_size, 
+                 p_dropout, window_size=None, spk_emb_dim=64, n_spks=1):
+        super(TextEncoder, self).__init__()
+
+        self.register(
+            n_vocab=n_vocab,
+            n_feats=n_feats,
+            n_channels=n_channels,
+            filter_channels=filter_channels,
+            filter_channels_dp=filter_channels_dp,
+            n_heads=n_heads,
+            n_layers=n_layers,
+            kernel_size=kernel_size,
+            p_dropout=p_dropout,
+            window_size=window_size,
+            spk_emb_dim=spk_emb_dim,
+            n_spks=n_spks
+        )
+        
+        
+        self.n_vocab = n_vocab
+        self.n_feats = n_feats
+        self.n_channels = n_channels
+        self.filter_channels = filter_channels
+        self.filter_channels_dp = filter_channels_dp
+        self.n_heads = n_heads
+        self.n_layers = n_layers
+        self.kernel_size = kernel_size
+        self.p_dropout = p_dropout
+        self.window_size = window_size
+        self.spk_emb_dim = spk_emb_dim
+        self.n_spks = n_spks
+
+        self.emb = torch.nn.Embedding(n_vocab, n_channels)
+        torch.nn.init.normal_(self.emb.weight, 0.0, n_channels**-0.5)
+
+        self.prenet = ConvReluNorm(n_channels, n_channels, n_channels, 
+                                   kernel_size=5, n_layers=3, p_dropout=0.5)
+
+        self.encoder = Encoder(n_channels + (spk_emb_dim if n_spks > 1 else 0), filter_channels, n_heads, n_layers, 
+                               kernel_size, p_dropout, window_size=window_size)
+
+        self.proj_m = torch.nn.Conv1d(n_channels + (spk_emb_dim if n_spks > 1 else 0), n_feats, 1)
+        self.proj_w = DurationPredictor(n_channels + (spk_emb_dim if n_spks > 1 else 0), filter_channels_dp, 
+                                        kernel_size, p_dropout)
+
+    def forward(self, x, x_lengths, spk=None):
+        x = self.emb(x) * math.sqrt(self.n_channels)
+        x = torch.transpose(x, 1, -1)
+        x_mask = torch.unsqueeze(sequence_mask(x_lengths, x.size(2)), 1).to(x.dtype)
+
+        x = self.prenet(x, x_mask)
+        if self.n_spks > 1:
+            x = torch.cat([x, spk.unsqueeze(-1).repeat(1, 1, x.shape[-1])], dim=1)
+        x = self.encoder(x, x_mask)
+        mu = self.proj_m(x) * x_mask
+
+        x_dp = torch.detach(x)
+        logw = self.proj_w(x_dp, x_mask)
+
+        return mu, logw, x_mask

src/diffusers/pipelines/pipeline_latent_diffusion.py

@@ -903,8 +903,8 @@ class LatentDiffusion(DiffusionPipeline):
         image = torch.randn(
             (batch_size, self.unet.in_channels, self.unet.image_size, self.unet.image_size),
             generator=generator,
-        )
-        image = image.to(torch_device)
+        ).to(torch_device)
+
         # See formulas (12) and (16) of DDIM paper https://arxiv.org/pdf/2010.02502.pdf
         # Ideally, read DDIM paper in-detail understanding
 
@@ -937,46 +937,17 @@ class LatentDiffusion(DiffusionPipeline):
                 pred_noise_t_uncond, pred_noise_t = pred_noise_t.chunk(2)
                 pred_noise_t = pred_noise_t_uncond + guidance_scale * (pred_noise_t - pred_noise_t_uncond)
 
-            # 2. get actual t and t-1
-            train_step = inference_step_times[t]
-            prev_train_step = inference_step_times[t - 1] if t > 0 else -1
-
-            # 3. compute alphas, betas
-            alpha_prod_t = self.noise_scheduler.get_alpha_prod(train_step)
-            alpha_prod_t_prev = self.noise_scheduler.get_alpha_prod(prev_train_step)
-            beta_prod_t = 1 - alpha_prod_t
-            beta_prod_t_prev = 1 - alpha_prod_t_prev
-
-            # 4. Compute predicted previous image from predicted noise
-            # First: compute predicted original image from predicted noise also called
-            # "predicted x_0" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
-            pred_original_image = (image - beta_prod_t.sqrt() * pred_noise_t) / alpha_prod_t.sqrt()
-
-            # Second: Compute variance: "sigma_t(η)" -> see formula (16)
-            # σ_t = sqrt((1 − α_t−1)/(1 − α_t)) * sqrt(1 − α_t/α_t−1)
-            std_dev_t = (beta_prod_t_prev / beta_prod_t).sqrt() * (1 - alpha_prod_t / alpha_prod_t_prev).sqrt()
-            std_dev_t = eta * std_dev_t
-
-            # Third: Compute "direction pointing to x_t" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
-            pred_image_direction = (1 - alpha_prod_t_prev - std_dev_t**2).sqrt() * pred_noise_t
-
-            # Forth: Compute x_t without "random noise" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
-            pred_prev_image = alpha_prod_t_prev.sqrt() * pred_original_image + pred_image_direction
-
-            # 5. Sample x_t-1 image optionally if η > 0.0 by adding noise to pred_prev_image
-            # Note: eta = 1.0 essentially corresponds to DDPM
-            if eta > 0.0:
-                noise = torch.randn(
-                    (batch_size, self.unet.in_channels, self.unet.resolution, self.unet.resolution),
-                    generator=generator,
-                )
-                noise = noise.to(torch_device)
-                prev_image = pred_prev_image + std_dev_t * noise
-            else:
-                prev_image = pred_prev_image
+            # 2. predict previous mean of image x_t-1
+            pred_prev_image = self.noise_scheduler.step(pred_noise_t, image, t, num_inference_steps, eta)
+
+            # 3. optionally sample variance
+            variance = 0
+            if eta > 0:
+                noise = torch.randn(image.shape, generator=generator).to(image.device)
+                variance = self.noise_scheduler.get_variance(t, num_inference_steps).sqrt() * eta * noise
 
-            # 6. Set current image to prev_image: x_t -> x_t-1
-            image = prev_image
+            # 4. set current image to prev_image: x_t -> x_t-1
+            image = pred_prev_image + variance
 
         # scale and decode image with vae
         image = 1 / 0.18215 * image