app.py

import gradio as gr
import jax
import jax.numpy as jnp
import librosa
import dac_jax
import spaces
import tempfile
import os
import numpy as np

# Load the DAC model with padding set to False for chunking
model, variables = dac_jax.load_model(model_type="44khz", padding=False)

# Jit-compile these functions because they're used inside a loop over chunks.
@jax.jit
def compress_chunk(x):
    return model.apply(variables, x, method='compress_chunk')

@jax.jit
def decompress_chunk(c):
    return model.apply(variables, c, method='decompress_chunk')

@spaces.GPU
def encode(audio_file_path):
    try:
        # Load audio with librosa, specifying duration
        signal, sample_rate = librosa.load(audio_file_path, sr=44100, mono=True, duration=.5)  # Set duration as needed

        signal = jnp.array(signal, dtype=jnp.float32)
        while signal.ndim < 3:
            signal = jnp.expand_dims(signal, axis=0)

        win_duration = 0.5  # Adjust based on your GPU's memory size
        dac_file = model.compress(compress_chunk, signal, sample_rate, win_duration=win_duration)

        # Save to a temporary file
        with tempfile.NamedTemporaryFile(delete=False, suffix=".dac") as temp_file:
            dac_file.save(temp_file.name)

        return temp_file.name

    except Exception as e:
        gr.Warning(f"An error occurred during encoding: {e}")
        return None

@spaces.GPU
def decode(compressed_dac_file):
    try:
        # Load from the uploaded file
        with tempfile.NamedTemporaryFile(delete=False, suffix=".dac") as temp_file:
            temp_file.write(compressed_dac_file.file.read())
            temp_file_path = temp_file.name

        dac_file = dac_jax.DACFile.load(temp_file_path)
        y = model.decompress(decompress_chunk, dac_file)
        decoded_audio = np.array(y).squeeze()

        os.unlink(temp_file_path)
        return (44100, decoded_audio)

    except Exception as e:
        gr.Warning(f"An error occurred during decoding: {e}")
        return None

# Gradio interface
with gr.Blocks() as demo:
    gr.Markdown("<h1 style='text-align: center;'>Audio Compression with DAC-JAX</h1>")

    with gr.Tab("Encode"):
        with gr.Row():
            audio_input = gr.Audio(type="filepath", label="Input Audio")
            encode_button = gr.Button("Encode", variant="primary")
        with gr.Row():
            encoded_output = gr.File(label="Compressed Audio (.dac)")

        encode_button.click(encode, inputs=audio_input, outputs=encoded_output)

    with gr.Tab("Decode"):
        with gr.Row():
            compressed_input = gr.File(label="Compressed Audio (.dac)")
            decode_button = gr.Button("Decode", variant="primary")
        with gr.Row():
            decoded_output = gr.Audio(label="Decompressed Audio")

        decode_button.click(decode, inputs=compressed_input, outputs=decoded_output)

demo.queue().launch()