initial commit

TTS/tts/layers/tortoise/arch_utils.py

@@ -0,0 +1,371 @@
+import os
+import functools
+import math
+
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+import torchaudio
+from tortoise.models.xtransformers import ContinuousTransformerWrapper, RelativePositionBias
+
+
+def zero_module(module):
+    """
+    Zero out the parameters of a module and return it.
+    """
+    for p in module.parameters():
+        p.detach().zero_()
+    return module
+
+
+class GroupNorm32(nn.GroupNorm):
+    def forward(self, x):
+        return super().forward(x.float()).type(x.dtype)
+
+
+def normalization(channels):
+    """
+    Make a standard normalization layer.
+
+    :param channels: number of input channels.
+    :return: an nn.Module for normalization.
+    """
+    groups = 32
+    if channels <= 16:
+        groups = 8
+    elif channels <= 64:
+        groups = 16
+    while channels % groups != 0:
+        groups = int(groups / 2)
+    assert groups > 2
+    return GroupNorm32(groups, channels)
+
+
+class QKVAttentionLegacy(nn.Module):
+    """
+    A module which performs QKV attention. Matches legacy QKVAttention + input/output heads shaping
+    """
+
+    def __init__(self, n_heads):
+        super().__init__()
+        self.n_heads = n_heads
+
+    def forward(self, qkv, mask=None, rel_pos=None):
+        """
+        Apply QKV attention.
+
+        :param qkv: an [N x (H * 3 * C) x T] tensor of Qs, Ks, and Vs.
+        :return: an [N x (H * C) x T] tensor after attention.
+        """
+        bs, width, length = qkv.shape
+        assert width % (3 * self.n_heads) == 0
+        ch = width // (3 * self.n_heads)
+        q, k, v = qkv.reshape(bs * self.n_heads, ch * 3, length).split(ch, dim=1)
+        scale = 1 / math.sqrt(math.sqrt(ch))
+        weight = torch.einsum(
+            "bct,bcs->bts", q * scale, k * scale
+        )  # More stable with f16 than dividing afterwards
+        if rel_pos is not None:
+            weight = rel_pos(weight.reshape(bs, self.n_heads, weight.shape[-2], weight.shape[-1])).reshape(bs * self.n_heads, weight.shape[-2], weight.shape[-1])
+        weight = torch.softmax(weight.float(), dim=-1).type(weight.dtype)
+        if mask is not None:
+            # The proper way to do this is to mask before the softmax using -inf, but that doesn't work properly on CPUs.
+            mask = mask.repeat(self.n_heads, 1).unsqueeze(1)
+            weight = weight * mask
+        a = torch.einsum("bts,bcs->bct", weight, v)
+
+        return a.reshape(bs, -1, length)
+
+
+class AttentionBlock(nn.Module):
+    """
+    An attention block that allows spatial positions to attend to each other.
+
+    Originally ported from here, but adapted to the N-d case.
+    https://github.com/hojonathanho/diffusion/blob/1e0dceb3b3495bbe19116a5e1b3596cd0706c543/diffusion_tf/models/unet.py#L66.
+    """
+
+    def __init__(
+        self,
+        channels,
+        num_heads=1,
+        num_head_channels=-1,
+        do_checkpoint=True,
+        relative_pos_embeddings=False,
+    ):
+        super().__init__()
+        self.channels = channels
+        self.do_checkpoint = do_checkpoint
+        if num_head_channels == -1:
+            self.num_heads = num_heads
+        else:
+            assert (
+                channels % num_head_channels == 0
+            ), f"q,k,v channels {channels} is not divisible by num_head_channels {num_head_channels}"
+            self.num_heads = channels // num_head_channels
+        self.norm = normalization(channels)
+        self.qkv = nn.Conv1d(channels, channels * 3, 1)
+        # split heads before split qkv
+        self.attention = QKVAttentionLegacy(self.num_heads)
+
+        self.proj_out = zero_module(nn.Conv1d(channels, channels, 1))
+        if relative_pos_embeddings:
+            self.relative_pos_embeddings = RelativePositionBias(scale=(channels // self.num_heads) ** .5, causal=False, heads=num_heads, num_buckets=32, max_distance=64)
+        else:
+            self.relative_pos_embeddings = None
+
+    def forward(self, x, mask=None):
+        b, c, *spatial = x.shape
+        x = x.reshape(b, c, -1)
+        qkv = self.qkv(self.norm(x))
+        h = self.attention(qkv, mask, self.relative_pos_embeddings)
+        h = self.proj_out(h)
+        return (x + h).reshape(b, c, *spatial)
+
+
+class Upsample(nn.Module):
+    """
+    An upsampling layer with an optional convolution.
+
+    :param channels: channels in the inputs and outputs.
+    :param use_conv: a bool determining if a convolution is applied.
+    """
+
+    def __init__(self, channels, use_conv, out_channels=None, factor=4):
+        super().__init__()
+        self.channels = channels
+        self.out_channels = out_channels or channels
+        self.use_conv = use_conv
+        self.factor = factor
+        if use_conv:
+            ksize = 5
+            pad = 2
+            self.conv = nn.Conv1d(self.channels, self.out_channels, ksize, padding=pad)
+
+    def forward(self, x):
+        assert x.shape[1] == self.channels
+        x = F.interpolate(x, scale_factor=self.factor, mode="nearest")
+        if self.use_conv:
+            x = self.conv(x)
+        return x
+
+
+class Downsample(nn.Module):
+    """
+    A downsampling layer with an optional convolution.
+
+    :param channels: channels in the inputs and outputs.
+    :param use_conv: a bool determining if a convolution is applied.
+    """
+
+    def __init__(self, channels, use_conv, out_channels=None, factor=4, ksize=5, pad=2):
+        super().__init__()
+        self.channels = channels
+        self.out_channels = out_channels or channels
+        self.use_conv = use_conv
+
+        stride = factor
+        if use_conv:
+            self.op = nn.Conv1d(
+                self.channels, self.out_channels, ksize, stride=stride, padding=pad
+            )
+        else:
+            assert self.channels == self.out_channels
+            self.op = nn.AvgPool1d(kernel_size=stride, stride=stride)
+
+    def forward(self, x):
+        assert x.shape[1] == self.channels
+        return self.op(x)
+
+
+class ResBlock(nn.Module):
+    def __init__(
+            self,
+            channels,
+            dropout,
+            out_channels=None,
+            use_conv=False,
+            use_scale_shift_norm=False,
+            up=False,
+            down=False,
+            kernel_size=3,
+    ):
+        super().__init__()
+        self.channels = channels
+        self.dropout = dropout
+        self.out_channels = out_channels or channels
+        self.use_conv = use_conv
+        self.use_scale_shift_norm = use_scale_shift_norm
+        padding = 1 if kernel_size == 3 else 2
+
+        self.in_layers = nn.Sequential(
+            normalization(channels),
+            nn.SiLU(),
+            nn.Conv1d(channels, self.out_channels, kernel_size, padding=padding),
+        )
+
+        self.updown = up or down
+
+        if up:
+            self.h_upd = Upsample(channels, False)
+            self.x_upd = Upsample(channels, False)
+        elif down:
+            self.h_upd = Downsample(channels, False)
+            self.x_upd = Downsample(channels, False)
+        else:
+            self.h_upd = self.x_upd = nn.Identity()
+
+        self.out_layers = nn.Sequential(
+            normalization(self.out_channels),
+            nn.SiLU(),
+            nn.Dropout(p=dropout),
+            zero_module(
+                nn.Conv1d(self.out_channels, self.out_channels, kernel_size, padding=padding)
+            ),
+        )
+
+        if self.out_channels == channels:
+            self.skip_connection = nn.Identity()
+        elif use_conv:
+            self.skip_connection = nn.Conv1d(
+                channels, self.out_channels, kernel_size, padding=padding
+            )
+        else:
+            self.skip_connection = nn.Conv1d(channels, self.out_channels, 1)
+
+    def forward(self, x):
+        if self.updown:
+            in_rest, in_conv = self.in_layers[:-1], self.in_layers[-1]
+            h = in_rest(x)
+            h = self.h_upd(h)
+            x = self.x_upd(x)
+            h = in_conv(h)
+        else:
+            h = self.in_layers(x)
+        h = self.out_layers(h)
+        return self.skip_connection(x) + h
+
+
+class AudioMiniEncoder(nn.Module):
+    def __init__(self,
+                 spec_dim,
+                 embedding_dim,
+                 base_channels=128,
+                 depth=2,
+                 resnet_blocks=2,
+                 attn_blocks=4,
+                 num_attn_heads=4,
+                 dropout=0,
+                 downsample_factor=2,
+                 kernel_size=3):
+        super().__init__()
+        self.init = nn.Sequential(
+            nn.Conv1d(spec_dim, base_channels, 3, padding=1)
+        )
+        ch = base_channels
+        res = []
+        for l in range(depth):
+            for r in range(resnet_blocks):
+                res.append(ResBlock(ch, dropout, kernel_size=kernel_size))
+            res.append(Downsample(ch, use_conv=True, out_channels=ch*2, factor=downsample_factor))
+            ch *= 2
+        self.res = nn.Sequential(*res)
+        self.final = nn.Sequential(
+            normalization(ch),
+            nn.SiLU(),
+            nn.Conv1d(ch, embedding_dim, 1)
+        )
+        attn = []
+        for a in range(attn_blocks):
+            attn.append(AttentionBlock(embedding_dim, num_attn_heads,))
+        self.attn = nn.Sequential(*attn)
+        self.dim = embedding_dim
+
+    def forward(self, x):
+        h = self.init(x)
+        h = self.res(h)
+        h = self.final(h)
+        h = self.attn(h)
+        return h[:, :, 0]
+
+
+DEFAULT_MEL_NORM_FILE = os.path.join(os.path.dirname(os.path.realpath(__file__)), '../data/mel_norms.pth')
+
+
+class TorchMelSpectrogram(nn.Module):
+    def __init__(self, filter_length=1024, hop_length=256, win_length=1024, n_mel_channels=80, mel_fmin=0, mel_fmax=8000,
+                 sampling_rate=22050, normalize=False, mel_norm_file=DEFAULT_MEL_NORM_FILE):
+        super().__init__()
+        # These are the default tacotron values for the MEL spectrogram.
+        self.filter_length = filter_length
+        self.hop_length = hop_length
+        self.win_length = win_length
+        self.n_mel_channels = n_mel_channels
+        self.mel_fmin = mel_fmin
+        self.mel_fmax = mel_fmax
+        self.sampling_rate = sampling_rate
+        self.mel_stft = torchaudio.transforms.MelSpectrogram(n_fft=self.filter_length, hop_length=self.hop_length,
+                                                             win_length=self.win_length, power=2, normalized=normalize,
+                                                             sample_rate=self.sampling_rate, f_min=self.mel_fmin,
+                                                             f_max=self.mel_fmax, n_mels=self.n_mel_channels,
+                                                             norm="slaney")
+        self.mel_norm_file = mel_norm_file
+        if self.mel_norm_file is not None:
+            self.mel_norms = torch.load(self.mel_norm_file)
+        else:
+            self.mel_norms = None
+
+    def forward(self, inp):
+        if len(inp.shape) == 3:  # Automatically squeeze out the channels dimension if it is present (assuming mono-audio)
+            inp = inp.squeeze(1)
+        assert len(inp.shape) == 2
+        self.mel_stft = self.mel_stft.to(inp.device)
+        mel = self.mel_stft(inp)
+        # Perform dynamic range compression
+        mel = torch.log(torch.clamp(mel, min=1e-5))
+        if self.mel_norms is not None:
+            self.mel_norms = self.mel_norms.to(mel.device)
+            mel = mel / self.mel_norms.unsqueeze(0).unsqueeze(-1)
+        return mel
+
+
+class CheckpointedLayer(nn.Module):
+    """
+    Wraps a module. When forward() is called, passes kwargs that require_grad through torch.checkpoint() and bypasses
+    checkpoint for all other args.
+    """
+    def __init__(self, wrap):
+        super().__init__()
+        self.wrap = wrap
+
+    def forward(self, x, *args, **kwargs):
+        for k, v in kwargs.items():
+            assert not (isinstance(v, torch.Tensor) and v.requires_grad)  # This would screw up checkpointing.
+        partial = functools.partial(self.wrap, **kwargs)
+        return partial(x, *args)
+
+
+class CheckpointedXTransformerEncoder(nn.Module):
+    """
+    Wraps a ContinuousTransformerWrapper and applies CheckpointedLayer to each layer and permutes from channels-mid
+    to channels-last that XTransformer expects.
+    """
+    def __init__(self, needs_permute=True, exit_permute=True, checkpoint=True, **xtransformer_kwargs):
+        super().__init__()
+        self.transformer = ContinuousTransformerWrapper(**xtransformer_kwargs)
+        self.needs_permute = needs_permute
+        self.exit_permute = exit_permute
+
+        if not checkpoint:
+            return
+        for i in range(len(self.transformer.attn_layers.layers)):
+            n, b, r = self.transformer.attn_layers.layers[i]
+            self.transformer.attn_layers.layers[i] = nn.ModuleList([n, CheckpointedLayer(b), r])
+
+    def forward(self, x, **kwargs):
+        if self.needs_permute:
+            x = x.permute(0,2,1)
+        h = self.transformer(x, **kwargs)
+        if self.exit_permute:
+            h = h.permute(0,2,1)
+        return h

TTS/tts/layers/tortoise/clvp.py

@@ -0,0 +1,155 @@
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+from torch import einsum
+
+from tortoise.models.arch_util import CheckpointedXTransformerEncoder
+from tortoise.models.transformer import Transformer
+from tortoise.models.xtransformers import Encoder
+
+
+def exists(val):
+    return val is not None
+
+
+def masked_mean(t, mask, dim = 1):
+    t = t.masked_fill(~mask[:, :, None], 0.)
+    return t.sum(dim = 1) / mask.sum(dim = 1)[..., None]
+
+class CLVP(nn.Module):
+    """
+    CLIP model retrofitted for performing contrastive evaluation between tokenized audio data and the corresponding
+    transcribed text.
+
+    Originally from https://github.com/lucidrains/DALLE-pytorch/blob/main/dalle_pytorch/dalle_pytorch.py
+    """
+
+    def __init__(
+            self,
+            *,
+            dim_text=512,
+            dim_speech=512,
+            dim_latent=512,
+            num_text_tokens=256,
+            text_enc_depth=6,
+            text_seq_len=120,
+            text_heads=8,
+            num_speech_tokens=8192,
+            speech_enc_depth=6,
+            speech_heads=8,
+            speech_seq_len=250,
+            text_mask_percentage=0,
+            voice_mask_percentage=0,
+            wav_token_compression=1024,
+            use_xformers=False,
+    ):
+        super().__init__()
+        self.text_emb = nn.Embedding(num_text_tokens, dim_text)
+        self.to_text_latent = nn.Linear(dim_text, dim_latent, bias=False)
+
+        self.speech_emb = nn.Embedding(num_speech_tokens, dim_speech)
+        self.to_speech_latent = nn.Linear(dim_speech, dim_latent, bias=False)
+
+        if use_xformers:
+            self.text_transformer = CheckpointedXTransformerEncoder(
+                needs_permute=False,
+                exit_permute=False,
+                max_seq_len=-1,
+                attn_layers=Encoder(
+                    dim=dim_text,
+                    depth=text_enc_depth,
+                    heads=text_heads,
+                    ff_dropout=.1,
+                    ff_mult=2,
+                    attn_dropout=.1,
+                    use_rmsnorm=True,
+                    ff_glu=True,
+                    rotary_pos_emb=True,
+                ))
+            self.speech_transformer = CheckpointedXTransformerEncoder(
+                needs_permute=False,
+                exit_permute=False,
+                max_seq_len=-1,
+                attn_layers=Encoder(
+                    dim=dim_speech,
+                    depth=speech_enc_depth,
+                    heads=speech_heads,
+                    ff_dropout=.1,
+                    ff_mult=2,
+                    attn_dropout=.1,
+                    use_rmsnorm=True,
+                    ff_glu=True,
+                    rotary_pos_emb=True,
+                ))
+        else:
+            self.text_transformer = Transformer(causal=False, seq_len=text_seq_len, dim=dim_text, depth=text_enc_depth,
+                                                heads=text_heads)
+            self.speech_transformer = Transformer(causal=False, seq_len=speech_seq_len, dim=dim_speech,
+                                                  depth=speech_enc_depth, heads=speech_heads)
+
+        self.temperature = nn.Parameter(torch.tensor(1.))
+        self.text_mask_percentage = text_mask_percentage
+        self.voice_mask_percentage = voice_mask_percentage
+        self.wav_token_compression = wav_token_compression
+        self.xformers = use_xformers
+        if not use_xformers:
+            self.text_pos_emb = nn.Embedding(text_seq_len, dim_text)
+            self.speech_pos_emb = nn.Embedding(num_speech_tokens, dim_speech)
+
+    def forward(
+            self,
+            text,
+            speech_tokens,
+            return_loss=False
+    ):
+        b, device = text.shape[0], text.device
+        if self.training:
+            text_mask = torch.rand_like(text.float()) > self.text_mask_percentage
+            voice_mask = torch.rand_like(speech_tokens.float()) > self.voice_mask_percentage
+        else:
+            text_mask = torch.ones_like(text.float()).bool()
+            voice_mask = torch.ones_like(speech_tokens.float()).bool()
+
+        text_emb = self.text_emb(text)
+        speech_emb = self.speech_emb(speech_tokens)
+
+        if not self.xformers:
+            text_emb += self.text_pos_emb(torch.arange(text.shape[1], device=device))
+            speech_emb += self.speech_pos_emb(torch.arange(speech_emb.shape[1], device=device))
+
+        enc_text = self.text_transformer(text_emb, mask=text_mask)
+        enc_speech = self.speech_transformer(speech_emb, mask=voice_mask)
+
+        text_latents = masked_mean(enc_text, text_mask, dim=1)
+        speech_latents = masked_mean(enc_speech, voice_mask, dim=1)
+
+        text_latents = self.to_text_latent(text_latents)
+        speech_latents = self.to_speech_latent(speech_latents)
+
+        text_latents, speech_latents = map(lambda t: F.normalize(t, p=2, dim=-1), (text_latents, speech_latents))
+
+        temp = self.temperature.exp()
+
+        if not return_loss:
+            sim = einsum('n d, n d -> n', text_latents, speech_latents) * temp
+            return sim
+
+        sim = einsum('i d, j d -> i j', text_latents, speech_latents) * temp
+        labels = torch.arange(b, device=device)
+        loss = (F.cross_entropy(sim, labels) + F.cross_entropy(sim.t(), labels)) / 2
+        return loss
+
+
+if __name__ == '__main__':
+    clip = CLVP(text_mask_percentage=.2, voice_mask_percentage=.2)
+    clip(torch.randint(0,256,(2,120)),
+         torch.tensor([50,100]),
+         torch.randint(0,8192,(2,250)),
+         torch.tensor([101,102]),
+         return_loss=True)
+    nonloss = clip(torch.randint(0,256,(2,120)),
+         torch.tensor([50,100]),
+         torch.randint(0,8192,(2,250)),
+         torch.tensor([101,102]),
+         return_loss=False)
+    print(nonloss.shape)

TTS/tts/layers/tortoise/unifiedvoice.py

@@ -0,0 +1,511 @@
+import functools
+
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+from transformers import GPT2Config, GPT2PreTrainedModel, LogitsProcessorList
+from transformers.modeling_outputs import CausalLMOutputWithCrossAttentions
+from transformers.utils.model_parallel_utils import get_device_map, assert_device_map
+from tortoise.models.arch_util import AttentionBlock
+from tortoise.utils.typical_sampling import TypicalLogitsWarper
+
+
+def null_position_embeddings(range, dim):
+    return torch.zeros((range.shape[0], range.shape[1], dim), device=range.device)
+
+
+class ResBlock(nn.Module):
+    """
+    Basic residual convolutional block that uses GroupNorm.
+    """
+    def __init__(self, chan):
+        super().__init__()
+        self.net = nn.Sequential(
+            nn.Conv1d(chan, chan, kernel_size=3, padding=1),
+            nn.GroupNorm(chan//8, chan),
+            nn.ReLU(),
+            nn.Conv1d(chan, chan, kernel_size=3, padding=1),
+            nn.GroupNorm(chan//8, chan)
+        )
+
+    def forward(self, x):
+        return F.relu(self.net(x) + x)
+
+
+class GPT2InferenceModel(GPT2PreTrainedModel):
+    def __init__(self, config, gpt, text_pos_emb, embeddings, norm, linear):
+        super().__init__(config)
+        self.transformer = gpt
+        self.text_pos_embedding = text_pos_emb
+        self.embeddings = embeddings
+        self.lm_head = nn.Sequential(norm, linear)
+
+        # Model parallel
+        self.model_parallel = False
+        self.device_map = None
+        self.cached_mel_emb = None
+
+    def parallelize(self, device_map=None):
+        self.device_map = (
+            get_device_map(len(self.transformer.h), range(torch.cuda.device_count()))
+            if device_map is None
+            else device_map
+        )
+        assert_device_map(self.device_map, len(self.transformer.h))
+        self.transformer.parallelize(self.device_map)
+        self.lm_head = self.lm_head.to(self.transformer.first_device)
+        self.model_parallel = True
+
+    def deparallelize(self):
+        self.transformer.deparallelize()
+        self.transformer = self.transformer.to("cpu")
+        self.lm_head = self.lm_head.to("cpu")
+        self.model_parallel = False
+        torch.cuda.empty_cache()
+
+    def get_output_embeddings(self):
+        return self.lm_head
+
+    def set_output_embeddings(self, new_embeddings):
+        self.lm_head = new_embeddings
+
+    def store_mel_emb(self, mel_emb):
+        self.cached_mel_emb = mel_emb
+
+    def prepare_inputs_for_generation(self, input_ids, past=None, **kwargs):
+
+        token_type_ids = kwargs.get("token_type_ids", None)
+        # only last token for inputs_ids if past is defined in kwargs
+        if past:
+            input_ids = input_ids[:, -1].unsqueeze(-1)
+            if token_type_ids is not None:
+                token_type_ids = token_type_ids[:, -1].unsqueeze(-1)
+
+        attention_mask = kwargs.get("attention_mask", None)
+        position_ids = kwargs.get("position_ids", None)
+
+        if attention_mask is not None and position_ids is None:
+            # create position_ids on the fly for batch generation
+            position_ids = attention_mask.long().cumsum(-1) - 1
+            position_ids.masked_fill_(attention_mask == 0, 1)
+            if past:
+                position_ids = position_ids[:, -1].unsqueeze(-1)
+        else:
+            position_ids = None
+        return {
+            "input_ids": input_ids,
+            "past_key_values": past,
+            "use_cache": kwargs.get("use_cache"),
+            "position_ids": position_ids,
+            "attention_mask": attention_mask,
+            "token_type_ids": token_type_ids,
+        }
+
+    def forward(
+        self,
+        input_ids=None,
+        past_key_values=None,
+        attention_mask=None,
+        token_type_ids=None,
+        position_ids=None,
+        head_mask=None,
+        inputs_embeds=None,
+        encoder_hidden_states=None,
+        encoder_attention_mask=None,
+        labels=None,
+        use_cache=None,
+        output_attentions=None,
+        output_hidden_states=None,
+        return_dict=None,
+    ):
+        assert self.cached_mel_emb is not None
+        assert inputs_embeds is None  # Not supported by this inference model.
+        assert labels is None  # Training not supported by this inference model.
+        return_dict = return_dict if return_dict is not None else self.config.use_return_dict
+
+        # Create embedding
+        mel_len = self.cached_mel_emb.shape[1]
+        if input_ids.shape[1] != 1:
+            text_inputs = input_ids[:, mel_len:]
+            text_emb = self.embeddings(text_inputs)
+            text_emb = text_emb + self.text_pos_embedding(text_emb)
+            if self.cached_mel_emb.shape[0] != text_emb.shape[0]:
+                mel_emb = self.cached_mel_emb.repeat_interleave(text_emb.shape[0]//self.cached_mel_emb.shape[0], 0)
+            else:
+                mel_emb = self.cached_mel_emb
+            emb = torch.cat([mel_emb, text_emb], dim=1)
+        else:
+            emb = self.embeddings(input_ids)
+            emb = emb + self.text_pos_embedding.get_fixed_embedding(attention_mask.shape[1]-mel_len, attention_mask.device)
+
+        transformer_outputs = self.transformer(
+            inputs_embeds=emb,
+            past_key_values=past_key_values,
+            attention_mask=attention_mask,
+            token_type_ids=token_type_ids,
+            position_ids=position_ids,
+            head_mask=head_mask,
+            encoder_hidden_states=encoder_hidden_states,
+            encoder_attention_mask=encoder_attention_mask,
+            use_cache=use_cache,
+            output_attentions=output_attentions,
+            output_hidden_states=output_hidden_states,
+            return_dict=return_dict,
+        )
+        hidden_states = transformer_outputs[0]
+
+        # Set device for model parallelism
+        if self.model_parallel:
+            torch.cuda.set_device(self.transformer.first_device)
+            hidden_states = hidden_states.to(self.lm_head.weight.device)
+
+        lm_logits = self.lm_head(hidden_states)
+
+        if not return_dict:
+            return (lm_logits,) + transformer_outputs[1:]
+
+        return CausalLMOutputWithCrossAttentions(
+            loss=None,
+            logits=lm_logits,
+            past_key_values=transformer_outputs.past_key_values,
+            hidden_states=transformer_outputs.hidden_states,
+            attentions=transformer_outputs.attentions,
+            cross_attentions=transformer_outputs.cross_attentions,
+        )
+
+    @staticmethod
+    def _reorder_cache(past, beam_idx):
+        """
+        This function is used to re-order the :obj:`past_key_values` cache if
+        :meth:`~transformers.PreTrainedModel.beam_search` or :meth:`~transformers.PreTrainedModel.beam_sample` is
+        called. This is required to match :obj:`past_key_values` with the correct beam_idx at every generation step.
+        """
+        return tuple(
+            tuple(past_state.index_select(0, beam_idx.to(past_state.device)) for past_state in layer_past)
+            for layer_past in past
+        )
+
+
+class ConditioningEncoder(nn.Module):
+    def __init__(self,
+                 spec_dim,
+                 embedding_dim,
+                 attn_blocks=6,
+                 num_attn_heads=4,
+                 do_checkpointing=False,
+                 mean=False):
+        super().__init__()
+        attn = []
+        self.init = nn.Conv1d(spec_dim, embedding_dim, kernel_size=1)
+        for a in range(attn_blocks):
+            attn.append(AttentionBlock(embedding_dim, num_attn_heads))
+        self.attn = nn.Sequential(*attn)
+        self.dim = embedding_dim
+        self.do_checkpointing = do_checkpointing
+        self.mean = mean
+
+    def forward(self, x):
+        h = self.init(x)
+        h = self.attn(h)
+        if self.mean:
+            return h.mean(dim=2)
+        else:
+            return h[:, :, 0]
+
+
+class LearnedPositionEmbeddings(nn.Module):
+    def __init__(self, seq_len, model_dim, init=.02):
+        super().__init__()
+        self.emb = nn.Embedding(seq_len, model_dim)
+        # Initializing this way is standard for GPT-2
+        self.emb.weight.data.normal_(mean=0.0, std=init)
+
+    def forward(self, x):
+        sl = x.shape[1]
+        return self.emb(torch.arange(0, sl, device=x.device))
+
+    def get_fixed_embedding(self, ind, dev):
+        return self.emb(torch.tensor([ind], device=dev)).unsqueeze(0)
+
+
+def build_hf_gpt_transformer(layers, model_dim, heads, max_mel_seq_len, max_text_seq_len, checkpointing):
+    """
+    GPT-2 implemented by the HuggingFace library.
+    """
+    from transformers import GPT2Config, GPT2Model
+    gpt_config = GPT2Config(vocab_size=256,  # Unused.
+                             n_positions=max_mel_seq_len+max_text_seq_len,
+                             n_ctx=max_mel_seq_len+max_text_seq_len,
+                             n_embd=model_dim,
+                             n_layer=layers,
+                             n_head=heads,
+                             gradient_checkpointing=checkpointing,
+                             use_cache=not checkpointing)
+    gpt = GPT2Model(gpt_config)
+    # Override the built in positional embeddings
+    del gpt.wpe
+    gpt.wpe = functools.partial(null_position_embeddings, dim=model_dim)
+    # Built-in token embeddings are unused.
+    del gpt.wte
+    return gpt, LearnedPositionEmbeddings(max_mel_seq_len, model_dim), LearnedPositionEmbeddings(max_text_seq_len, model_dim),\
+           None, None
+
+
+class MelEncoder(nn.Module):
+    def __init__(self, channels, mel_channels=80, resblocks_per_reduction=2):
+        super().__init__()
+        self.channels = channels
+        self.encoder = nn.Sequential(nn.Conv1d(mel_channels, channels//4, kernel_size=3, padding=1),
+                                     nn.Sequential(*[ResBlock(channels//4) for _ in range(resblocks_per_reduction)]),
+                                     nn.Conv1d(channels//4, channels//2, kernel_size=3, stride=2, padding=1),
+                                     nn.GroupNorm(channels//16, channels//2),
+                                     nn.ReLU(),
+                                     nn.Sequential(*[ResBlock(channels//2) for _ in range(resblocks_per_reduction)]),
+                                     nn.Conv1d(channels//2, channels, kernel_size=3, stride=2, padding=1),
+                                     nn.GroupNorm(channels//8, channels),
+                                     nn.ReLU(),
+                                     nn.Sequential(*[ResBlock(channels) for _ in range(resblocks_per_reduction)]),
+                                     )
+        self.reduction = 4
+
+
+    def forward(self, x):
+        for e in self.encoder:
+            x = e(x)
+        return x.permute(0,2,1)
+
+
+class UnifiedVoice(nn.Module):
+    def __init__(self, layers=8, model_dim=512, heads=8, max_text_tokens=120, max_mel_tokens=250, max_conditioning_inputs=1,
+                 mel_length_compression=1024, number_text_tokens=256,
+                 start_text_token=None, number_mel_codes=8194, start_mel_token=8192,
+                 stop_mel_token=8193, train_solo_embeddings=False, use_mel_codes_as_input=True,
+                 checkpointing=True, types=1):
+        """
+        Args:
+            layers: Number of layers in transformer stack.
+            model_dim: Operating dimensions of the transformer
+            heads: Number of transformer heads. Must be divisible by model_dim. Recommend model_dim//64
+            max_text_tokens: Maximum number of text tokens that will be encountered by model.
+            max_mel_tokens: Maximum number of MEL tokens that will be encountered by model.
+            max_conditioning_inputs: Maximum number of conditioning inputs provided to the model. If (1), conditioning input can be of format (b,80,s), otherwise (b,n,80,s).
+            mel_length_compression: The factor between <number_input_samples> and <mel_tokens>. Used to compute MEL code padding given wav input length.
+            number_text_tokens:
+            start_text_token:
+            stop_text_token:
+            number_mel_codes:
+            start_mel_token:
+            stop_mel_token:
+            train_solo_embeddings:
+            use_mel_codes_as_input:
+            checkpointing:
+        """
+        super().__init__()
+
+        self.number_text_tokens = number_text_tokens
+        self.start_text_token = number_text_tokens * types if start_text_token is None else start_text_token
+        self.stop_text_token = 0
+        self.number_mel_codes = number_mel_codes
+        self.start_mel_token = start_mel_token
+        self.stop_mel_token = stop_mel_token
+        self.layers = layers
+        self.heads = heads
+        self.max_mel_tokens = max_mel_tokens
+        self.max_text_tokens = max_text_tokens
+        self.model_dim = model_dim
+        self.max_conditioning_inputs = max_conditioning_inputs
+        self.mel_length_compression = mel_length_compression
+        self.conditioning_encoder = ConditioningEncoder(80, model_dim, num_attn_heads=heads)
+        self.text_embedding = nn.Embedding(self.number_text_tokens*types+1, model_dim)
+        if use_mel_codes_as_input:
+            self.mel_embedding = nn.Embedding(self.number_mel_codes, model_dim)
+        else:
+            self.mel_embedding = MelEncoder(model_dim, resblocks_per_reduction=1)
+        self.gpt, self.mel_pos_embedding, self.text_pos_embedding, self.mel_layer_pos_embedding, self.text_layer_pos_embedding = \
+            build_hf_gpt_transformer(layers, model_dim, heads, self.max_mel_tokens+2+self.max_conditioning_inputs, self.max_text_tokens+2, checkpointing)
+        if train_solo_embeddings:
+            self.mel_solo_embedding = nn.Parameter(torch.randn(1, 1, model_dim) * .02, requires_grad=True)
+            self.text_solo_embedding = nn.Parameter(torch.randn(1, 1, model_dim) * .02, requires_grad=True)
+        else:
+            self.mel_solo_embedding = 0
+            self.text_solo_embedding = 0
+
+        self.final_norm = nn.LayerNorm(model_dim)
+        self.text_head = nn.Linear(model_dim, self.number_text_tokens*types+1)
+        self.mel_head = nn.Linear(model_dim, self.number_mel_codes)
+
+        # Initialize the embeddings per the GPT-2 scheme
+        embeddings = [self.text_embedding]
+        if use_mel_codes_as_input:
+            embeddings.append(self.mel_embedding)
+        for module in embeddings:
+            module.weight.data.normal_(mean=0.0, std=.02)
+
+    def build_aligned_inputs_and_targets(self, input, start_token, stop_token):
+        inp = F.pad(input, (1,0), value=start_token)
+        tar = F.pad(input, (0,1), value=stop_token)
+        return inp, tar
+
+    def set_mel_padding(self, mel_input_tokens, wav_lengths):
+        """
+        Given mel tokens that are derived from a padded audio clip and the actual lengths of each batch element in
+        that audio clip, reformats the tokens with STOP_MEL_TOKEN in place of the zero padding. This is required
+        preformatting to create a working TTS model.
+        """
+        # Set padding areas within MEL (currently it is coded with the MEL code for <zero>).
+        mel_lengths = torch.div(wav_lengths, self.mel_length_compression, rounding_mode='trunc')
+        for b in range(len(mel_lengths)):
+            actual_end = mel_lengths[b] + 1  # Due to the convolutional nature of how these tokens are generated, it would be best if the model predicts a token past the actual last token.
+            if actual_end < mel_input_tokens.shape[-1]:
+                mel_input_tokens[b, actual_end:] = self.stop_mel_token
+        return mel_input_tokens
+
+    def get_logits(self, speech_conditioning_inputs, first_inputs, first_head, second_inputs=None, second_head=None, get_attns=False, return_latent=False):
+        if second_inputs is not None:
+            emb = torch.cat([speech_conditioning_inputs, first_inputs, second_inputs], dim=1)
+        else:
+            emb = torch.cat([speech_conditioning_inputs, first_inputs], dim=1)
+
+        gpt_out = self.gpt(inputs_embeds=emb, return_dict=True, output_attentions=get_attns)
+        if get_attns:
+            return gpt_out.attentions
+
+        enc = gpt_out.last_hidden_state[:, 1:]  # The first logit is tied to the speech_conditioning_input
+        enc = self.final_norm(enc)
+
+        if return_latent:
+            return enc[:, speech_conditioning_inputs.shape[1]:speech_conditioning_inputs.shape[1]+first_inputs.shape[1]], enc[:, -second_inputs.shape[1]:]
+
+        first_logits = enc[:, :first_inputs.shape[1]]
+        first_logits = first_head(first_logits)
+        first_logits = first_logits.permute(0,2,1)
+        if second_inputs is not None:
+            second_logits = enc[:, -second_inputs.shape[1]:]
+            second_logits = second_head(second_logits)
+            second_logits = second_logits.permute(0,2,1)
+            return first_logits, second_logits
+        else:
+            return first_logits
+
+    def get_conditioning(self, speech_conditioning_input):
+        speech_conditioning_input = speech_conditioning_input.unsqueeze(1) if len(
+            speech_conditioning_input.shape) == 3 else speech_conditioning_input
+        conds = []
+        for j in range(speech_conditioning_input.shape[1]):
+            conds.append(self.conditioning_encoder(speech_conditioning_input[:, j]))
+        conds = torch.stack(conds, dim=1)
+        conds = conds.mean(dim=1)
+        return conds
+
+    def forward(self, speech_conditioning_latent, text_inputs, text_lengths, mel_codes, wav_lengths, types=None, text_first=True, raw_mels=None, return_attentions=False,
+                return_latent=False, clip_inputs=True):
+        """
+        Forward pass that uses both text and voice in either text conditioning mode or voice conditioning mode
+        (actuated by `text_first`).
+
+        speech_conditioning_input: MEL float tensor, (b,1024)
+        text_inputs: long tensor, (b,t)
+        text_lengths: long tensor, (b,)
+        mel_inputs:  long tensor, (b,m)
+        wav_lengths: long tensor, (b,)
+        raw_mels: MEL float tensor (b,80,s)
+
+        If return_attentions is specified, only logits are returned.
+        If return_latent is specified, loss & logits are not computed or returned. Only the predicted latents are returned.
+        If clip_inputs is True, the inputs will be clipped to the smallest input size across each input modality.
+        """
+        # Types are expressed by expanding the text embedding space.
+        if types is not None:
+            text_inputs = text_inputs * (1+types).unsqueeze(-1)
+
+        if clip_inputs:
+            # This model will receive micro-batches with a ton of padding for both the text and MELs. Ameliorate this by
+            # chopping the inputs by the maximum actual length.
+            max_text_len = text_lengths.max()
+            text_inputs = text_inputs[:, :max_text_len]
+            max_mel_len = wav_lengths.max() // self.mel_length_compression
+            mel_codes = mel_codes[:, :max_mel_len]
+            if raw_mels is not None:
+                raw_mels = raw_mels[:, :, :max_mel_len*4]
+        mel_codes = self.set_mel_padding(mel_codes, wav_lengths)
+        text_inputs = F.pad(text_inputs, (0,1), value=self.stop_text_token)
+        mel_codes = F.pad(mel_codes, (0,1), value=self.stop_mel_token)
+
+        conds = speech_conditioning_latent.unsqueeze(1)
+        text_inputs, text_targets = self.build_aligned_inputs_and_targets(text_inputs, self.start_text_token, self.stop_text_token)
+        text_emb = self.text_embedding(text_inputs) + self.text_pos_embedding(text_inputs)
+        mel_codes, mel_targets = self.build_aligned_inputs_and_targets(mel_codes, self.start_mel_token, self.stop_mel_token)
+        if raw_mels is not None:
+            mel_inp = F.pad(raw_mels, (0, 8))
+        else:
+            mel_inp = mel_codes
+        mel_emb = self.mel_embedding(mel_inp)
+        mel_emb = mel_emb + self.mel_pos_embedding(mel_codes)
+
+        if text_first:
+            text_logits, mel_logits = self.get_logits(conds, text_emb, self.text_head, mel_emb, self.mel_head, get_attns=return_attentions, return_latent=return_latent)
+            if return_latent:
+                return mel_logits[:, :-2]  # Despite the name, these are not logits. Strip off the two tokens added by this forward pass.
+        else:
+            mel_logits, text_logits = self.get_logits(conds, mel_emb, self.mel_head, text_emb, self.text_head, get_attns=return_attentions, return_latent=return_latent)
+            if return_latent:
+                return text_logits[:, :-2]  # Despite the name, these are not logits. Strip off the two tokens added by this forward pass.
+
+        if return_attentions:
+            return mel_logits
+        loss_text = F.cross_entropy(text_logits, text_targets.long())
+        loss_mel = F.cross_entropy(mel_logits, mel_targets.long())
+        return loss_text.mean(), loss_mel.mean(), mel_logits
+
+    def inference_speech(self, speech_conditioning_latent, text_inputs, input_tokens=None, num_return_sequences=1,
+                         max_generate_length=None, typical_sampling=False, typical_mass=.9, **hf_generate_kwargs):
+        seq_length = self.max_mel_tokens + self.max_text_tokens + 2
+        if not hasattr(self, 'inference_model'):
+            # TODO: Decouple gpt_config from this inference model.
+            gpt_config = GPT2Config(vocab_size=self.max_mel_tokens,
+                                    n_positions=seq_length,
+                                    n_ctx=seq_length,
+                                    n_embd=self.model_dim,
+                                    n_layer=self.layers,
+                                    n_head=self.heads,
+                                    gradient_checkpointing=False,
+                                    use_cache=True)
+            self.inference_model = GPT2InferenceModel(gpt_config, self.gpt, self.mel_pos_embedding, self.mel_embedding, self.final_norm, self.mel_head)
+            self.gpt.wte = self.mel_embedding
+
+        text_inputs = F.pad(text_inputs, (0, 1), value=self.stop_text_token)
+        text_inputs, text_targets = self.build_aligned_inputs_and_targets(text_inputs, self.start_text_token, self.stop_text_token)
+        text_emb = self.text_embedding(text_inputs) + self.text_pos_embedding(text_inputs)
+
+        conds = speech_conditioning_latent.unsqueeze(1)
+        emb = torch.cat([conds, text_emb], dim=1)
+        self.inference_model.store_mel_emb(emb)
+
+        fake_inputs = torch.full((emb.shape[0], conds.shape[1] + emb.shape[1],), fill_value=1, dtype=torch.long,
+                                 device=text_inputs.device)
+        fake_inputs[:, -1] = self.start_mel_token
+        trunc_index = fake_inputs.shape[1]
+        if input_tokens is None:
+            inputs = fake_inputs
+        else:
+            assert num_return_sequences % input_tokens.shape[0] == 0, "The number of return sequences must be divisible by the number of input sequences"
+            fake_inputs = fake_inputs.repeat(num_return_sequences, 1)
+            input_tokens = input_tokens.repeat(num_return_sequences // input_tokens.shape[0], 1)
+            inputs = torch.cat([fake_inputs, input_tokens], dim=1)
+
+        logits_processor = LogitsProcessorList([TypicalLogitsWarper(mass=typical_mass)]) if typical_sampling else LogitsProcessorList()
+        max_length = trunc_index + self.max_mel_tokens - 1  if max_generate_length is None else trunc_index + max_generate_length
+        gen = self.inference_model.generate(inputs, bos_token_id=self.start_mel_token, pad_token_id=self.stop_mel_token, eos_token_id=self.stop_mel_token,
+                                            max_length=max_length, logits_processor=logits_processor,
+                                            num_return_sequences=num_return_sequences, **hf_generate_kwargs)
+        return gen[:, trunc_index:]
+
+
+if __name__ == '__main__':
+    gpt = UnifiedVoice(model_dim=256, heads=4, train_solo_embeddings=True, use_mel_codes_as_input=True, max_conditioning_inputs=4)
+    l = gpt(torch.randn(2, 3, 80, 800),
+            torch.randint(high=120, size=(2,120)),
+            torch.tensor([32, 120]),
+            torch.randint(high=8192, size=(2,250)),
+            torch.tensor([250*256,195*256]))
+    gpt.text_forward(torch.randn(2,80,800), torch.randint(high=50, size=(2,80)), torch.tensor([32, 80]))