app.py

import os
from typing import List
import gradio as gr
import tempfile
import numpy as np
import librosa
import soundfile as sf
import spaces
from audiosr import super_resolution
from audiosr_utils import load_audiosr


audiosr_model = load_audiosr()


def split_audio_to_chunks(y, sr=48000, chunk_duration=5.12) -> List[str]:
    # Calculate the number of samples per chunk
    chunk_samples = int(chunk_duration * sr)

    # Split the audio into chunks
    chunks = [y[i : i + chunk_samples] for i in range(0, len(y), chunk_samples)]

    # Save each chunk to a temporary file
    temp_files = []
    for i, chunk in enumerate(chunks):
        # Create a temporary file
        temp_file = tempfile.NamedTemporaryFile(delete=False, suffix=".wav")
        temp_files.append(temp_file.name)

        # Write the chunk to the temporary file
        sf.write(temp_file.name, chunk, sr)

    return temp_files


@spaces.GPU()
def run_audiosr(
    chunks: List[str], guidance_scale: float, ddim_steps: int
) -> np.ndarray:
    waveforms = []
    for i, chunk in enumerate(chunks):
        print(f"Processing chunk {i+1}/{len(chunks)}")
        waveform = super_resolution(
            audiosr_model,
            chunk,
            guidance_scale=guidance_scale,
            ddim_steps=ddim_steps,
        )
        waveforms.append(waveform)
    waveform = np.concatenate(waveforms, axis=-1)  # (1, 1, N)
    waveform = waveform.squeeze()
    return waveform


def audiosr_infer(audio: str) -> str:
    guidance_scale = 3.5
    ddim_steps = 100

    y, sr = librosa.load(audio, sr=48000)
    if len(y) > 60 * sr:
        y = y[: 60 * sr]
        gr.Info("Audio is too long, only the first 60 seconds will be processed")

    chunk_files = split_audio_to_chunks(y, sr=sr, chunk_duration=5.12)
    print(f"Splited audio chunks: {chunk_files}")

    waveform = run_audiosr(chunk_files, guidance_scale, ddim_steps)
    sr = 44100

    for chunk_file in chunk_files:
        os.remove(chunk_file)

    with tempfile.NamedTemporaryFile(suffix=".mp3", delete=False) as f:
        sf.write(f.name, waveform, sr)
        return f.name


models = {
    "AudioSR": audiosr_infer,
}


def infer(audio: str, model: str, sr: int) -> str:
    if sr > 0:
        # resample audio
        y, _ = librosa.load(audio, sr=sr)
        # save resampled audio
        with tempfile.NamedTemporaryFile(suffix=".wav", delete=False) as f:
            sf.write(f.name, y, sr)
            return models[model](f.name)
    else:
        return models[model](audio)


with gr.Blocks() as app:
    with open(os.path.join(os.path.dirname(__file__), "README.md"), "r") as f:
        README = f.read()
        # remove yaml front matter
        blocks = README.split("---")
        if len(blocks) > 1:
            README = "---".join(blocks[2:])

    gr.Markdown(README)

    with gr.Row():
        with gr.Column():
            gr.Markdown("## Upload an audio file")
            audio = gr.Audio(label="Upload an audio file", type="filepath")
            sr = gr.Slider(
                value=0,
                label="Resample audio to sample rate before inference, 0 means no resampling",
                minimum=0,
                maximum=48000,
                step=1000,
            )

    with gr.Row():
        model = gr.Radio(
            label="Select a model",
            choices=[s for s in models.keys()],
            value="AudioSR",
        )
        btn = gr.Button("Infer")

    with gr.Row():
        with gr.Column():
            out = gr.Audio(
                label="Output", format="mp3", type="filepath", interactive=False
            )

    btn.click(
        fn=infer,
        inputs=[audio, model, sr],
        outputs=[out],
        api_name="infer",
    )

app.launch(show_error=True)