app.py

import gradio as gr
import torch
import soundfile as sf
import numpy as np
import yaml
from inference import MasteringStyleTransfer
from utils import download_youtube_audio
from config import args
import pyloudnorm as pyln
import tempfile
import os
import pandas as pd

mastering_transfer = MasteringStyleTransfer(args)

def denormalize_audio(audio, dtype=np.int16):
    """
    Denormalize the audio from the range [-1, 1] to the full range of the specified dtype.
    """
    if dtype == np.int16:
        audio = np.clip(audio, -1, 1)  # Ensure the input is in the range [-1, 1]
        return (audio * 32767).astype(np.int16)
    elif dtype == np.float32:
        return audio.astype(np.float32)
    else:
        raise ValueError("Unsupported dtype. Use np.int16 or np.float32.")

def loudness_normalize(audio, sample_rate, target_loudness=-12.0):
    # Ensure audio is float32
    if audio.dtype != np.float32:
        audio = audio.astype(np.float32)
    
    # If audio is mono, reshape to (samples, 1)
    if audio.ndim == 1:
        audio = audio.reshape(-1, 1)
    
    meter = pyln.Meter(sample_rate)  # create BS.1770 meter
    loudness = meter.integrated_loudness(audio)
    
    loudness_normalized_audio = pyln.normalize.loudness(audio, loudness, target_loudness)
    return loudness_normalized_audio

def process_youtube_url(url):
    try:
        audio, sr = download_youtube_audio(url)
        return (sr, audio)
    except Exception as e:
        return None, f"Error processing YouTube URL: {str(e)}"

def process_audio_with_youtube(input_audio, input_youtube_url, reference_audio, reference_youtube_url):
    if input_youtube_url:
        input_audio, error = process_youtube_url(input_youtube_url)
        if error:
            return None, None, error
    
    if reference_youtube_url:
        reference_audio, error = process_youtube_url(reference_youtube_url)
        if error:
            return None, None, error
    
    if input_audio is None or reference_audio is None:
        return None, None, "Both input and reference audio are required."
    
    return process_audio(input_audio, reference_audio)

def process_audio(input_audio, reference_audio):
    output_audio, predicted_params, sr = mastering_transfer.process_audio(
        input_audio, reference_audio, reference_audio
    )
    
    param_output = mastering_transfer.get_param_output_string(predicted_params)
    
    # Convert output_audio to numpy array if it's a tensor
    if isinstance(output_audio, torch.Tensor):
        output_audio = output_audio.cpu().numpy()

    if output_audio.ndim == 1:
        output_audio = output_audio.reshape(-1, 1)
    elif output_audio.ndim > 2:
        output_audio = output_audio.squeeze()

    # Ensure the audio is in the correct shape (samples, channels)
    if output_audio.shape[1] > output_audio.shape[0]:
        output_audio = output_audio.transpose(1,0)

    print(output_audio.shape)
    print(f"sr: {sr}")

    # Normalize output audio
    output_audio = loudness_normalize(output_audio, sr)    
    # Denormalize the audio to int16
    output_audio = denormalize_audio(output_audio, dtype=np.int16)

    return (sr, output_audio), param_output

def perform_ito(input_audio, reference_audio, ito_reference_audio, num_steps, optimizer, learning_rate, af_weights):
    if ito_reference_audio is None:
        ito_reference_audio = reference_audio

    ito_config = {
        'optimizer': optimizer,
        'learning_rate': learning_rate,
        'num_steps': num_steps,
        'af_weights': af_weights,
        'sample_rate': args.sample_rate
    }

    input_tensor = mastering_transfer.preprocess_audio(input_audio, args.sample_rate)
    reference_tensor = mastering_transfer.preprocess_audio(reference_audio, args.sample_rate)
    ito_reference_tensor = mastering_transfer.preprocess_audio(ito_reference_audio, args.sample_rate)

    initial_reference_feature = mastering_transfer.get_reference_embedding(reference_tensor)

    ito_log = ""
    loss_values = []
    for log_entry, current_output, current_params, step, loss in mastering_transfer.inference_time_optimization(
        input_tensor, ito_reference_tensor, ito_config, initial_reference_feature
    ):
        ito_log += log_entry
        ito_param_output = mastering_transfer.get_param_output_string(current_params)
        loss_values.append({"step": int(step), "loss": loss})
        
        # Convert current_output to numpy array if it's a tensor
        if isinstance(current_output, torch.Tensor):
            current_output = current_output.cpu().numpy()
                    
        if current_output.ndim == 1:
            current_output = current_output.reshape(-1, 1)
        elif current_output.ndim > 2:
            current_output = current_output.squeeze()
        # Ensure the audio is in the correct shape (samples, channels)
        if current_output.shape[1] > current_output.shape[0]:
            current_output = current_output.transpose(1,0)

        # Loudness normalize output audio
        current_output = loudness_normalize(current_output, args.sample_rate)
        # Denormalize the audio to int16
        current_output = denormalize_audio(current_output, dtype=np.int16)

        yield (args.sample_rate, current_output), ito_param_output, step, ito_log, pd.DataFrame(loss_values)


""" APP display """
with gr.Blocks() as demo:
    gr.Markdown("# Mastering Style Transfer Demo")

    with gr.Tab("Upload Audio"):
        with gr.Row():
            input_audio = gr.Audio(label="Input Audio")
            reference_audio = gr.Audio(label="Reference Audio")
        
        process_button = gr.Button("Process Mastering Style Transfer")
        
        with gr.Row():
            output_audio = gr.Audio(label="Output Audio", type='numpy')
            param_output = gr.Textbox(label="Predicted Parameters", lines=5)

        process_button.click(
            process_audio, 
            inputs=[input_audio, reference_audio], 
            outputs=[output_audio, param_output]
        )

    with gr.Tab("YouTube Audio"):
        with gr.Row():
            input_audio_yt = gr.Audio(label="Input Audio (Optional)")
            input_youtube_url = gr.Textbox(label="Input YouTube URL (Optional)")
        with gr.Row():
            reference_audio_yt = gr.Audio(label="Reference Audio (Optional)")
            reference_youtube_url = gr.Textbox(label="Reference YouTube URL (Optional)")
        
        process_button_yt = gr.Button("Process Mastering Style Transfer")
        
        with gr.Row():
            output_audio_yt = gr.Audio(label="Output Audio", type='numpy')
            param_output_yt = gr.Textbox(label="Predicted Parameters", lines=5)
        
        error_message_yt = gr.Textbox(label="Error Message", visible=False)

        def process_and_handle_errors(input_audio, input_youtube_url, reference_audio, reference_youtube_url):
            result = process_audio_with_youtube(input_audio, input_youtube_url, reference_audio, reference_youtube_url)
            if len(result) == 3 and isinstance(result[2], str):  # Error occurred
                return None, None, gr.update(visible=True, value=result[2])
            return result[0], result[1], gr.update(visible=False, value="")

        process_button_yt.click(
            process_and_handle_errors, 
            inputs=[input_audio_yt, input_youtube_url, reference_audio_yt, reference_youtube_url], 
            outputs=[output_audio_yt, param_output_yt, error_message_yt]
        )

    gr.Markdown("## Inference Time Optimization (ITO)")
    
    with gr.Row():
        ito_reference_audio = gr.Audio(label="ITO Reference Audio (optional)")
        with gr.Column():
            num_steps = gr.Slider(minimum=1, maximum=100, value=10, step=1, label="Number of Steps")
            optimizer = gr.Dropdown(["Adam", "RAdam", "SGD"], value="RAdam", label="Optimizer")
            learning_rate = gr.Slider(minimum=0.0001, maximum=0.1, value=0.001, step=0.0001, label="Learning Rate")
            af_weights = gr.Textbox(label="AudioFeatureLoss Weights (comma-separated)", value="0.1,0.001,1.0,1.0,0.1")
        
    ito_button = gr.Button("Perform ITO")

    with gr.Row():
        with gr.Column():
            ito_output_audio = gr.Audio(label="ITO Output Audio")
            ito_param_output = gr.Textbox(label="ITO Predicted Parameters", lines=15)
        with gr.Column():
            ito_loss_plot = gr.LinePlot(
                x="step",
                y="loss",
                title="ITO Loss Curve",
                x_title="Step",
                y_title="Loss",
                height=300,
                width=600,
            )
            ito_log = gr.Textbox(label="ITO Log", lines=10)

    def run_ito(input_audio, reference_audio, ito_reference_audio, num_steps, optimizer, learning_rate, af_weights):
        af_weights = [float(w.strip()) for w in af_weights.split(',')]
        ito_generator = perform_ito(
            input_audio, reference_audio, ito_reference_audio, num_steps, optimizer, learning_rate, af_weights
        )
        
        # Initialize variables to store the final results
        final_audio = None
        final_params = None
        final_steps = 0
        final_log = ""
        loss_df = None
        
        # Iterate through the generator to get the final results
        for audio, params, steps, log, loss_data in ito_generator:
            final_audio = audio
            final_params = params
            final_steps = steps
            final_log = log
            loss_df = loss_data

        # Calculate y_min and y_max
        y_min = loss_df['loss'].min()
        y_max = loss_df['loss'].max()

        # Create a new plot configuration
        plot_config = {
            "x": "step",
            "y": "loss",
            "title": "ITO Loss Curve",
            "x_title": "Step",
            "y_title": "Loss",
            "height": 300,
            "width": 600,
            "y_lim": [y_min, y_max],
        }

        # Return the plot configuration along with the data
        return final_audio, final_params, final_log, (plot_config, loss_df)


    ito_button.click(
        run_ito,
        inputs=[input_audio, reference_audio, ito_reference_audio, num_steps, optimizer, learning_rate, af_weights],
        outputs=[ito_output_audio, ito_param_output, ito_log, ito_loss_plot]
    )

demo.launch()