from models.diffusion.fp16_util import convert_module_to_f32, convert_module_to_f16 from models.diffusion.nn import timestep_embedding, normalization, zero_module, conv_nd, linear from models.diffusion.unet_diffusion import AttentionPool2d, AttentionBlock, ResBlock, TimestepEmbedSequential, \ Downsample, Upsample import torch import torch.nn as nn from models.vqvae.vqvae import Quantize from trainer.networks import register_model import models.gpt_voice.my_dvae as mdvae from utils.util import checkpoint class DiscreteEncoder(nn.Module): def __init__(self, in_channels, model_channels, out_channels, dropout, scale): super().__init__() self.blocks = nn.Sequential( conv_nd(1, in_channels, model_channels, 3, padding=1), mdvae.ResBlock(model_channels, dropout, dims=1), Downsample(model_channels, use_conv=True, dims=1, out_channels=model_channels*2, factor=scale), mdvae.ResBlock(model_channels*2, dropout, dims=1), Downsample(model_channels*2, use_conv=True, dims=1, out_channels=model_channels*4, factor=scale), mdvae.ResBlock(model_channels*4, dropout, dims=1), AttentionBlock(model_channels*4, num_heads=4), mdvae.ResBlock(model_channels*4, dropout, out_channels=out_channels, dims=1), ) def forward(self, spectrogram): return checkpoint(self.blocks, spectrogram) class DiscreteDecoder(nn.Module): def __init__(self, in_channels, level_channels, scale): super().__init__() # Just raw upsampling, return a dict with each layer. self.init = conv_nd(1, in_channels, level_channels[0], kernel_size=3, padding=1) layers = [] for i, lvl in enumerate(level_channels[:-1]): layers.append(nn.Sequential(normalization(lvl), nn.SiLU(lvl), Upsample(lvl, use_conv=True, dims=1, out_channels=level_channels[i+1], factor=scale))) self.layers = nn.ModuleList(layers) def forward(self, x): y = self.init(x) outs = [y] for layer in self.layers: y = layer(y) outs.append(y) return outs class DiffusionDVAE(nn.Module): def __init__( self, model_channels, num_res_blocks, in_channels=1, out_channels=2, # mean and variance spectrogram_channels=80, spectrogram_conditioning_levels=[3,4,5], # Levels at which spectrogram conditioning is applied to the waveform. dropout=0, # 106496 -> 26624 -> 6656 -> 16664 -> 416 -> 104 -> 26 for ~5secs@22050Hz channel_mult=(1, 2, 4, 8, 16, 32, 64), attention_resolutions=(16,32,64), conv_resample=True, dims=1, use_fp16=False, num_heads=1, num_head_channels=-1, num_heads_upsample=-1, use_scale_shift_norm=False, use_new_attention_order=False, kernel_size=5, quantize_dim=1024, num_discrete_codes=8192, scale_steps=4, ): super().__init__() if num_heads_upsample == -1: num_heads_upsample = num_heads self.in_channels = in_channels self.spectrogram_channels = spectrogram_channels self.model_channels = model_channels self.out_channels = out_channels self.num_res_blocks = num_res_blocks self.attention_resolutions = attention_resolutions self.dropout = dropout self.channel_mult = channel_mult self.conv_resample = conv_resample self.dtype = torch.float16 if use_fp16 else torch.float32 self.num_heads = num_heads self.num_head_channels = num_head_channels self.num_heads_upsample = num_heads_upsample self.dims = dims self.spectrogram_conditioning_levels = spectrogram_conditioning_levels self.scale_steps = scale_steps self.encoder = DiscreteEncoder(spectrogram_channels, model_channels*4, quantize_dim, dropout, scale_steps) self.quantizer = Quantize(quantize_dim, num_discrete_codes) # For recording codebook usage. self.codes = torch.zeros((131072,), dtype=torch.long) self.code_ind = 0 self.internal_step = 0 decoder_channels = [model_channels * channel_mult[s-1] for s in spectrogram_conditioning_levels] self.decoder = DiscreteDecoder(quantize_dim, decoder_channels[::-1], scale_steps) padding = 1 if kernel_size == 3 else 2 time_embed_dim = model_channels * 4 self.time_embed = nn.Sequential( linear(model_channels, time_embed_dim), nn.SiLU(), linear(time_embed_dim, time_embed_dim), ) self.input_blocks = nn.ModuleList( [ TimestepEmbedSequential( conv_nd(dims, in_channels, model_channels, kernel_size, padding=padding) ) ] ) self._feature_size = model_channels input_block_chans = [model_channels] ch = model_channels ds = 1 self.convergence_convs = nn.ModuleList([]) for level, mult in enumerate(channel_mult): if level in spectrogram_conditioning_levels: self.convergence_convs.append(conv_nd(dims, ch*2, ch, 1)) for _ in range(num_res_blocks): layers = [ ResBlock( ch, time_embed_dim, dropout, out_channels=mult * model_channels, dims=dims, use_scale_shift_norm=use_scale_shift_norm, kernel_size=kernel_size, ) ] ch = mult * model_channels if ds in attention_resolutions: layers.append( AttentionBlock( ch, num_heads=num_heads, num_head_channels=num_head_channels, use_new_attention_order=use_new_attention_order, ) ) self.input_blocks.append(TimestepEmbedSequential(*layers)) self._feature_size += ch input_block_chans.append(ch) if level != len(channel_mult) - 1: out_ch = ch self.input_blocks.append( TimestepEmbedSequential( Downsample( ch, conv_resample, dims=dims, out_channels=out_ch, factor=scale_steps ) ) ) ch = out_ch input_block_chans.append(ch) ds *= 2 self._feature_size += ch self.middle_block = TimestepEmbedSequential( ResBlock( ch, time_embed_dim, dropout, dims=dims, use_scale_shift_norm=use_scale_shift_norm, kernel_size=kernel_size, ), AttentionBlock( ch, num_heads=num_heads, num_head_channels=num_head_channels, use_new_attention_order=use_new_attention_order, ), ResBlock( ch, time_embed_dim, dropout, dims=dims, use_scale_shift_norm=use_scale_shift_norm, kernel_size=kernel_size, ), ) self._feature_size += ch self.output_blocks = nn.ModuleList([]) for level, mult in list(enumerate(channel_mult))[::-1]: for i in range(num_res_blocks + 1): ich = input_block_chans.pop() layers = [ ResBlock( ch + ich, time_embed_dim, dropout, out_channels=model_channels * mult, dims=dims, use_scale_shift_norm=use_scale_shift_norm, kernel_size=kernel_size, ) ] ch = model_channels * mult if ds in attention_resolutions: layers.append( AttentionBlock( ch, num_heads=num_heads_upsample, num_head_channels=num_head_channels, use_new_attention_order=use_new_attention_order, ) ) if level and i == num_res_blocks: out_ch = ch layers.append( Upsample(ch, conv_resample, dims=dims, out_channels=out_ch, factor=scale_steps) ) ds //= 2 self.output_blocks.append(TimestepEmbedSequential(*layers)) self._feature_size += ch self.out = nn.Sequential( normalization(ch), nn.SiLU(), zero_module(conv_nd(dims, model_channels, out_channels, kernel_size, padding=padding)), ) def convert_to_fp16(self): """ Convert the torso of the model to float16. """ self.input_blocks.apply(convert_module_to_f16) self.middle_block.apply(convert_module_to_f16) self.output_blocks.apply(convert_module_to_f16) def convert_to_fp32(self): """ Convert the torso of the model to float32. """ self.input_blocks.apply(convert_module_to_f32) self.middle_block.apply(convert_module_to_f32) self.output_blocks.apply(convert_module_to_f32) def forward(self, x, timesteps, spectrogram): assert x.shape[-1] % 4096 == 0 # This model operates at base//4096 at it's bottom levels, thus this requirement. # Compute DVAE portion first. spec_logits = self.encoder(spectrogram).permute((0,2,1)) sampled, commitment_loss, codes = self.quantizer(spec_logits) if self.training: # Compute from softmax outputs to preserve gradients. sampled = sampled.permute((0,2,1)) else: # Compute from codes only. sampled = self.quantizer.embed_code(codes).permute((0,2,1)) spec_hs = self.decoder(sampled)[::-1] # Shape the spectrogram correctly. There is no guarantee it fits (though I probably should add an assertion here to make sure the resizing isn't too wacky.) spec_hs = [nn.functional.interpolate(sh, size=(x.shape[-1]//self.scale_steps**self.spectrogram_conditioning_levels[i],), mode='nearest') for i, sh in enumerate(spec_hs)] convergence_fns = list(self.convergence_convs) # The rest is the diffusion vocoder, built as a standard U-net. spec_h is gradually fed into the encoder. hs = [] emb = self.time_embed(timestep_embedding(timesteps, self.model_channels)) next_spec = spec_hs.pop(0) next_convergence_fn = convergence_fns.pop(0) h = x.type(self.dtype) for k, module in enumerate(self.input_blocks): h = module(h, emb) if next_spec is not None and h.shape[-1] == next_spec.shape[-1]: h = torch.cat([h, next_spec], dim=1) h = next_convergence_fn(h) if len(spec_hs) > 0: next_spec = spec_hs.pop(0) next_convergence_fn = convergence_fns.pop(0) else: next_spec = None hs.append(h) assert len(spec_hs) == 0 assert len(convergence_fns) == 0 h = self.middle_block(h, emb) for module in self.output_blocks: h = torch.cat([h, hs.pop()], dim=1) h = module(h, emb) h = h.type(x.dtype) return self.out(h), commitment_loss @register_model def register_unet_diffusion_dvae(opt_net, opt): return DiffusionDVAE(**opt_net['kwargs']) # Test for ~4 second audio clip at 22050Hz if __name__ == '__main__': clip = torch.randn(1, 1, 81920) spec = torch.randn(1, 80, 416) ts = torch.LongTensor([555]) model = DiffusionDVAE(32, 2) print(model(clip, ts, spec).shape)