import torch
import torch.nn as nn
import torch.nn.functional as F
from transformers import GPT2Model, GPT2Config
from models.arch_util import AttentionBlock
from models.gpt_voice.gpt_asr_hf import GPT2InferenceModel
from models.tacotron2.text import symbols
from trainer.networks import register_model
from utils.util import opt_get
class ConditioningEncoder(nn.Module):
def __init__(self,
spec_dim,
embedding_dim,
attn_blocks=6,
num_attn_heads=4,
do_checkpointing=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, do_checkpoint=do_checkpointing))
self.attn = nn.Sequential(*attn)
self.dim = embedding_dim
self.do_checkpointing = do_checkpointing
def forward(self, x):
h = self.init(x)
h = self.attn(h)
return h[:, :, 0]
class GptTtsHf(nn.Module):
NUMBER_TEXT_TOKENS = 256 # The number of tokens produced by our bespoke BPE tokenizer.
START_TEXT_TOKEN = 255
STOP_TEXT_TOKEN = 0
NUMBER_MEL_CODES = 8194
START_MEL_TOKEN = 8192
STOP_MEL_TOKEN = 8193
def __init__(self, layers=8, model_dim=512, heads=8, max_symbols_per_phrase=80, max_mel_tokens=250, max_conditioning_inputs=3,
checkpointing=True, mel_length_compression=1024, max_conditioning_length=60):
super().__init__()
self.max_mel_tokens = max_mel_tokens
self.max_symbols_per_phrase = max_symbols_per_phrase
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, model_dim)
seq_length = 2+self.max_symbols_per_phrase+self.max_conditioning_inputs+self.max_mel_tokens
self.gpt_config = GPT2Config(vocab_size=self.NUMBER_MEL_CODES,
n_positions=seq_length,
n_ctx=seq_length,
n_embd=model_dim,
n_layer=layers,
n_head=heads,
gradient_checkpointing=checkpointing,
use_cache=not checkpointing)
self.gpt = GPT2Model(self.gpt_config)
self.final_norm = nn.LayerNorm(model_dim)
self.text_head = nn.Linear(model_dim, self.NUMBER_TEXT_TOKENS)
self.mel_head = nn.Linear(model_dim, self.NUMBER_MEL_CODES)
self.max_conditioning_length = max_conditioning_length
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 get_logits(self, text_inputs, cond_input, mel_inputs, get_attns=False):
text_emb = self.text_embedding(text_inputs)
cond = self.conditioning_encoder(cond_input).unsqueeze(1)
mel_emb = self.gpt.get_input_embeddings()(mel_inputs)
emb = torch.cat([text_emb, cond, mel_emb], 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
text_logits = self.final_norm(enc[:, :text_emb.shape[1]])
text_logits = self.text_head(text_logits)
text_logits = text_logits.permute(0,2,1)
mel_logits = self.final_norm(enc[:, -mel_emb.shape[1]:])
mel_logits = self.mel_head(mel_logits)
mel_logits = mel_logits.permute(0,2,1)
return text_logits, mel_logits
def forward(self, text_inputs, cond_input, mel_targets, wav_lengths, return_attentions=False):
"""
Forward pass
text_inputs: long tensor, (b,t)
cond_inputs: MEL float tensor, (b,c,80,s)
mel_targets: long tensor, (b,m)
mel_lengths: long tensor, (b,)
"""
# Set padding areas within MEL (currently it is coded with the MEL code for <zero>).
mel_lengths = wav_lengths // self.mel_length_compression
for b in range(len(mel_lengths)):
if mel_lengths[b] < mel_targets.shape[-1]:
mel_targets[b, mel_lengths[b]:] = self.STOP_MEL_TOKEN
# Randomly permute the conditioning spectrogram, to destroy any structure present.
cond_input = cond_input[:,:,torch.randperm(cond_input.shape[-1])]
if cond_input.shape[-1] > self.max_conditioning_length:
cond_input = cond_input[:,:,:self.max_conditioning_length]
text_inputs, text_targets = self.build_aligned_inputs_and_targets(text_inputs, self.START_TEXT_TOKEN, self.STOP_TEXT_TOKEN)
mel_inputs, mel_targets = self.build_aligned_inputs_and_targets(mel_targets, self.START_MEL_TOKEN, self.STOP_MEL_TOKEN)
text_logits, mel_logits = self.get_logits(text_inputs, cond_input, mel_inputs, get_attns=return_attentions)
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(self, text_inputs, cond_input, **hf_generate_kwargs):
if not hasattr(self, 'inference_model'):
self.inference_model = GPT2InferenceModel(self.gpt_config, self.gpt, None, self.final_norm, self.mel_head)
text_inputs = F.pad(text_inputs, (0, self.max_symbols_per_phrase - text_inputs.shape[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)
# Randomly permute the conditioning spectrogram, to destroy any structure present.
cond_input = cond_input[:,:,torch.randperm(cond_input.shape[-1])]
if cond_input.shape[-1] > self.max_conditioning_length:
cond_input = cond_input[:,:,:self.max_conditioning_length]
cond = self.conditioning_encoder(cond_input).unsqueeze(1)
emb = torch.cat([text_emb, cond], dim=1)
self.inference_model.store_mel_emb(emb)
fake_inputs = torch.full((emb.shape[0],emb.shape[1]+1,), fill_value=1, dtype=torch.long, device=text_inputs.device)
fake_inputs[:,-1] = self.START_MEL_TOKEN
gen = self.inference_model.generate(fake_inputs, bos_token_id=self.START_MEL_TOKEN, pad_token_id=self.STOP_MEL_TOKEN, eos_token_id=self.STOP_MEL_TOKEN,
max_length=emb.shape[1]+self.max_mel_tokens, **hf_generate_kwargs)
return gen[:, fake_inputs.shape[1]:]
@register_model
def register_gpt_tts_hf(opt_net, opt):
return GptTtsHf(**opt_get(opt_net, ['kwargs'], {}))
if __name__ == '__main__':
gpt = GptTtsHf(model_dim=1024, heads=16)
l = gpt(torch.randint(high=len(symbols), size=(2,200)),
torch.arange(0, 80, 1, dtype=torch.float).view(1,80,1).repeat(2,1,800),
torch.randint(high=8192, size=(2,250)),
torch.tensor([150*256,195*256]))