app.py

import os

from dataclasses import asdict
from text import symbols
import torch
import torchaudio

from utils.audio import LogMelSpectrogram
from config import ModelConfig, VocosConfig, MelConfig
from models.model import StableTTS
from vocos_pytorch.models.model import Vocos
from text.english import english_to_ipa2
from text import cleaned_text_to_sequence
from datas.dataset import intersperse

import gradio as gr
import numpy as np
import matplotlib.pyplot as plt
from pathlib import Path

device = 'cpu'

@ torch.inference_mode()
def inference(text: str, ref_audio: torch.Tensor, checkpoint_path: str, step: int=10) -> torch.Tensor:
    global last_checkpoint_path
    if checkpoint_path != last_checkpoint_path:
        tts_model.load_state_dict(torch.load(checkpoint_path, map_location='cpu')) 
        last_checkpoint_path = checkpoint_path
        
    phonemizer = english_to_ipa2
    
    # prepare input for tts model
    x = torch.tensor(intersperse(cleaned_text_to_sequence(phonemizer(text)), item=0), dtype=torch.long, device=device).unsqueeze(0)
    x_len = torch.tensor([x.size(-1)], dtype=torch.long, device=device)
    waveform, sr = torchaudio.load(ref_audio)
    if sr != sample_rate:
        waveform = torchaudio.functional.resample(waveform, sr, sample_rate)
    y = mel_extractor(waveform).to(device)
    
    # inference
    mel = tts_model.synthesise(x, x_len, step, y=y, temperature=0.667, length_scale=1)['decoder_outputs']
    audio = vocoder(mel)
    
    # process output for gradio
    audio_output = (sample_rate, (audio.cpu().squeeze(0).numpy() * 32767).astype(np.int16)) # (samplerate, int16 audio) for gr.Audio
    mel_output = plot_mel_spectrogram(mel.cpu().squeeze(0).numpy()) # get the plot of mel
    return audio_output, mel_output

def get_pipeline(n_vocab: int, tts_model_config: ModelConfig, mel_config: MelConfig, vocoder_config: VocosConfig, tts_checkpoint_path, vocoder_checkpoint_path):
    tts_model = StableTTS(n_vocab, mel_config.n_mels, **asdict(tts_model_config))
    mel_extractor = LogMelSpectrogram(mel_config)
    vocoder = Vocos(vocoder_config, mel_config)
    # tts_model.load_state_dict(torch.load(tts_checkpoint_path, map_location='cpu'))
    tts_model.to(device)
    tts_model.eval()
    vocoder.load_state_dict(torch.load(vocoder_checkpoint_path, map_location='cpu'))
    vocoder.to(device)
    vocoder.eval()
    return tts_model, mel_extractor, vocoder

def plot_mel_spectrogram(mel_spectrogram):
    fig, ax = plt.subplots(figsize=(20, 8))
    ax.imshow(mel_spectrogram, aspect='auto', origin='lower')
    plt.axis('off')
    fig.subplots_adjust(left=0, right=1, top=1, bottom=0) # remove white edges
    return fig


def main():
    tts_model_config = ModelConfig()
    mel_config = MelConfig()
    vocoder_config = VocosConfig()

    tts_checkpoint_path = './checkpoints' # the folder that contains StableTTS checkpoints
    vocoder_checkpoint_path = './checkpoints/vocoder.pt'

    global tts_model, mel_extractor, vocoder, sample_rate, last_checkpoint_path
    sample_rate = mel_config.sample_rate
    last_checkpoint_path = None
    tts_model, mel_extractor, vocoder = get_pipeline(len(symbols), tts_model_config, mel_config, vocoder_config, tts_checkpoint_path, vocoder_checkpoint_path)
    
    tts_checkpoint_path = [path for path in Path(tts_checkpoint_path).rglob('*.pt') if 'optimizer' and 'vocoder' not in path.name]
    audios = list(Path('./audios').rglob('*.wav')) + list(Path('./audios').rglob('*.flac'))

    # gradio wabui
    gui_title = 'StableTTS'
    gui_description = """Next-generation TTS model using flow-matching and DiT, inspired by Stable Diffusion 3."""
    with gr.Blocks(analytics_enabled=False) as demo:

        with gr.Row():
            with gr.Column():
                gr.Markdown(f"# {gui_title}")
                gr.Markdown(gui_description)

        with gr.Row():
            with gr.Column():
                input_text_gr = gr.Textbox(
                    label="Input Text",
                    info="One or two sentences at a time is better. Up to 200 text characters.",
                    value="Today I want to tell you three stories from my life. That's it. No big deal. Just three stories.",
                )
             
                ref_audio_gr = gr.Dropdown(
                    label='reference audio',
                    choices=audios,
                    value = 0
                )
                
                
                checkpoint_gr = gr.Dropdown(
                    label='checkpoint',
                    choices=tts_checkpoint_path,
                    value = 0
                )
                
                step_gr = gr.Slider(
                    label='Step',
                    minimum=1,
                    maximum=40,
                    value=8,
                    step=1
                )


                tts_button = gr.Button("Send", elem_id="send-btn", visible=True)
                
            with gr.Column():
                mel_gr = gr.Plot(label="Mel Visual")
                audio_gr = gr.Audio(label="Synthesised Audio", autoplay=True)

        tts_button.click(inference, [input_text_gr, ref_audio_gr, checkpoint_gr, step_gr], outputs=[audio_gr, mel_gr])

    demo.queue()  
    demo.launch(debug=True, show_api=True)


if __name__ == '__main__':
    main()