Rex Cheng
initial commit
dbac20f
import torch
import torch.nn as nn
import torch.nn.functional as F
from einops import rearrange
from mmaudio.ext.autoencoder.edm2_utils import (MPConv1D, mp_silu, mp_sum, normalize)
def nonlinearity(x):
# swish
return mp_silu(x)
class ResnetBlock1D(nn.Module):
def __init__(self, *, in_dim, out_dim=None, conv_shortcut=False, kernel_size=3, use_norm=True):
super().__init__()
self.in_dim = in_dim
out_dim = in_dim if out_dim is None else out_dim
self.out_dim = out_dim
self.use_conv_shortcut = conv_shortcut
self.use_norm = use_norm
self.conv1 = MPConv1D(in_dim, out_dim, kernel_size=kernel_size)
self.conv2 = MPConv1D(out_dim, out_dim, kernel_size=kernel_size)
if self.in_dim != self.out_dim:
if self.use_conv_shortcut:
self.conv_shortcut = MPConv1D(in_dim, out_dim, kernel_size=kernel_size)
else:
self.nin_shortcut = MPConv1D(in_dim, out_dim, kernel_size=1)
def forward(self, x: torch.Tensor) -> torch.Tensor:
# pixel norm
if self.use_norm:
x = normalize(x, dim=1)
h = x
h = nonlinearity(h)
h = self.conv1(h)
h = nonlinearity(h)
h = self.conv2(h)
if self.in_dim != self.out_dim:
if self.use_conv_shortcut:
x = self.conv_shortcut(x)
else:
x = self.nin_shortcut(x)
return mp_sum(x, h, t=0.3)
class AttnBlock1D(nn.Module):
def __init__(self, in_channels, num_heads=1):
super().__init__()
self.in_channels = in_channels
self.num_heads = num_heads
self.qkv = MPConv1D(in_channels, in_channels * 3, kernel_size=1)
self.proj_out = MPConv1D(in_channels, in_channels, kernel_size=1)
def forward(self, x):
h = x
y = self.qkv(h)
y = y.reshape(y.shape[0], self.num_heads, -1, 3, y.shape[-1])
q, k, v = normalize(y, dim=2).unbind(3)
q = rearrange(q, 'b h c l -> b h l c')
k = rearrange(k, 'b h c l -> b h l c')
v = rearrange(v, 'b h c l -> b h l c')
h = F.scaled_dot_product_attention(q, k, v)
h = rearrange(h, 'b h l c -> b (h c) l')
h = self.proj_out(h)
return mp_sum(x, h, t=0.3)
class Upsample1D(nn.Module):
def __init__(self, in_channels, with_conv):
super().__init__()
self.with_conv = with_conv
if self.with_conv:
self.conv = MPConv1D(in_channels, in_channels, kernel_size=3)
def forward(self, x):
x = F.interpolate(x, scale_factor=2.0, mode='nearest-exact') # support 3D tensor(B,C,T)
if self.with_conv:
x = self.conv(x)
return x
class Downsample1D(nn.Module):
def __init__(self, in_channels, with_conv):
super().__init__()
self.with_conv = with_conv
if self.with_conv:
# no asymmetric padding in torch conv, must do it ourselves
self.conv1 = MPConv1D(in_channels, in_channels, kernel_size=1)
self.conv2 = MPConv1D(in_channels, in_channels, kernel_size=1)
def forward(self, x):
if self.with_conv:
x = self.conv1(x)
x = F.avg_pool1d(x, kernel_size=2, stride=2)
if self.with_conv:
x = self.conv2(x)
return x