Files
spark-pocket-tts/pocket_tts/modules/mimi_transformer.py
T

151 lines
4.9 KiB
Python

import torch
import torch.nn as nn
from torch.nn import functional as F
from typing_extensions import Self
from pocket_tts.modules.layer_scale import LayerScale
from pocket_tts.modules.rope import RotaryEmbedding
from pocket_tts.modules.transformer import StreamingMultiheadAttention
from pocket_tts.utils.config import FlowLMTransformerConfig
class StreamingTransformerLayer(nn.Module):
def __init__(
self,
d_model: int,
num_heads: int,
dim_feedforward: int,
context: int | None,
rope: RotaryEmbedding,
layer_scale: float | None = None,
):
super().__init__()
self.self_attn = StreamingMultiheadAttention(
rope=rope, embed_dim=d_model, num_heads=num_heads, context=context
)
self.norm1 = nn.LayerNorm(d_model, eps=1e-5)
self.norm2 = nn.LayerNorm(d_model, eps=1e-5)
self.linear1 = nn.Linear(d_model, dim_feedforward, bias=False)
self.linear2 = nn.Linear(dim_feedforward, d_model, bias=False)
if layer_scale is None:
self.layer_scale_1 = nn.Identity()
self.layer_scale_2 = nn.Identity()
else:
self.layer_scale_1 = LayerScale(d_model, layer_scale)
self.layer_scale_2 = LayerScale(d_model, layer_scale)
def _ff_block(self, x: torch.Tensor) -> torch.Tensor:
x_orig = x
x = self.norm2(x)
update = self.linear2(F.gelu(self.linear1(x)))
return x_orig.to(update) + self.layer_scale_2(update)
def _sa_block(self, x: torch.Tensor, model_state: dict | None) -> torch.Tensor:
x_orig = x
x = self.norm1(x)
update = self.self_attn(x, model_state)
return x_orig.to(update) + self.layer_scale_1(update)
def forward(self, x: torch.Tensor, model_state: dict | None) -> torch.Tensor:
x = self._sa_block(x, model_state)
x = self._ff_block(x)
return x
class StreamingTransformer(nn.Module):
def __init__(
self,
d_model: int,
num_heads: int,
num_layers: int,
layer_scale: float | None = None,
dim_feedforward: int | list[int] = 2048,
context: int | None = None,
max_period: float = 10_000.0,
):
super().__init__()
assert d_model % num_heads == 0
self.max_period = max_period
self.rope = RotaryEmbedding(max_period=max_period)
self.layers = nn.ModuleList()
for _ in range(num_layers):
self.layers.append(
StreamingTransformerLayer(
d_model=d_model,
num_heads=num_heads,
dim_feedforward=dim_feedforward,
context=context,
rope=self.rope,
layer_scale=layer_scale,
)
)
@classmethod
def from_pydantic_config(cls, config: FlowLMTransformerConfig) -> Self:
dim_feedforward = int(config.d_model * config.hidden_scale)
return cls(
d_model=config.d_model,
num_heads=config.num_heads,
num_layers=config.num_layers,
dim_feedforward=dim_feedforward,
max_period=float(config.max_period),
)
def forward(self, x: torch.Tensor, model_state: dict | None):
for layer in self.layers:
x = layer(x, model_state)
return x
class ProjectedTransformer(nn.Module):
def __init__(
self,
input_dimension: int,
output_dimensions: tuple[int, ...],
d_model: int,
num_heads: int,
num_layers: int,
layer_scale: float,
context: int,
max_period: float,
dim_feedforward: int,
):
super().__init__()
self.transformer = StreamingTransformer(
d_model=d_model,
num_heads=num_heads,
num_layers=num_layers,
layer_scale=layer_scale,
context=context,
max_period=max_period,
dim_feedforward=dim_feedforward,
)
self.input_dimension = input_dimension
self.output_dimensions = output_dimensions
self.input_proj = None
if d_model != input_dimension:
self.input_proj = nn.Linear(input_dimension, d_model, bias=False)
self.output_projs = nn.ModuleList()
for output_dimension in output_dimensions:
if d_model == output_dimension:
self.output_projs.append(nn.Identity())
else:
self.output_projs.append(nn.Linear(d_model, output_dimension, bias=False))
def forward(self, x, model_state: dict | None):
x = x.transpose(1, 2)
if self.input_proj is not None:
x = self.input_proj(x)
z = self.transformer(x, model_state)
ys = []
for output_proj in self.output_projs:
y = output_proj(z)
y = y.transpose(1, 2)
ys.append(y)
return ys