app.py

import gradio as gr
import torch
import torchaudio
import numpy as np
import tempfile
import time
from pathlib import Path
from huggingface_hub import hf_hub_download
import os
import spaces
from transformers import pipeline

# Import the inference module
from infer import DMOInference

# Global variables
model = None
asr_pipe = None
device = "cuda" if torch.cuda.is_available() else "cpu"

# Initialize ASR pipeline
def initialize_asr_pipeline(device=device, dtype=None):
    """Initialize the ASR pipeline on startup."""
    global asr_pipe
    
    if dtype is None:
        dtype = (
            torch.float16
            if "cuda" in device
            and torch.cuda.is_available()
            and torch.cuda.get_device_properties(device).major >= 7
            and not torch.cuda.get_device_name().endswith("[ZLUDA]")
            else torch.float32
        )
    
    print("Initializing ASR pipeline...")
    try:
        asr_pipe = pipeline(
            "automatic-speech-recognition",
            model="openai/whisper-large-v3-turbo",
            torch_dtype=dtype,
            device="cpu"  # Keep ASR on CPU to save GPU memory
        )
        print("ASR pipeline initialized successfully")
    except Exception as e:
        print(f"Error initializing ASR pipeline: {e}")
        asr_pipe = None

# Transcribe function
def transcribe(ref_audio, language=None):
    """Transcribe audio using the pre-loaded ASR pipeline."""
    global asr_pipe
    
    if asr_pipe is None:
        return ""  # Return empty string if ASR is not available
    
    try:
        result = asr_pipe(
            ref_audio,
            chunk_length_s=30,
            batch_size=128,
            generate_kwargs={"task": "transcribe", "language": language} if language else {"task": "transcribe"},
            return_timestamps=False,
        )
        return result["text"].strip()
    except Exception as e:
        print(f"Transcription error: {e}")
        return ""

def download_models():
    """Download models from HuggingFace Hub."""
    try:
        print("Downloading models from HuggingFace...")
        
        # Download student model
        student_path = hf_hub_download(
            repo_id="yl4579/DMOSpeech2",
            filename="model_85000.pt",
            cache_dir="./models"
        )
        
        # Download duration predictor
        duration_path = hf_hub_download(
            repo_id="yl4579/DMOSpeech2",
            filename="model_1500.pt",
            cache_dir="./models"
        )
        
        print(f"Student model: {student_path}")
        print(f"Duration model: {duration_path}")
        
        return student_path, duration_path
        
    except Exception as e:
        print(f"Error downloading models: {e}")
        return None, None

def initialize_model():
    """Initialize the model on startup."""
    global model
    
    try:
        # Download models
        student_path, duration_path = download_models()
        
        if not student_path or not duration_path:
            return False, "Failed to download models from HuggingFace"
        
        # Initialize model
        model = DMOInference(
            student_checkpoint_path=student_path,
            duration_predictor_path=duration_path,
            device=device,
            model_type="F5TTS_Base"
        )
        
        return True, f"Model loaded successfully on {device.upper()}"
        
    except Exception as e:
        return False, f"Error initializing model: {str(e)}"

# Initialize models on startup
print("Initializing models...")
model_loaded, status_message = initialize_model()
initialize_asr_pipeline()  # Initialize ASR pipeline

@spaces.GPU(duration=120)  # Request GPU for up to 120 seconds
def generate_speech(
    prompt_audio,
    prompt_text,
    target_text,
    mode,
    temperature,
    custom_teacher_steps,
    custom_teacher_stopping_time,
    custom_student_start_step,
    verbose
):
    """Generate speech with different configurations."""
    
    if not model_loaded or model is None:
        return None, "Model not loaded! Please refresh the page.", "", ""
    
    if prompt_audio is None:
        return None, "Please upload a reference audio!", "", ""
    
    if not target_text:
        return None, "Please enter text to generate!", "", ""
    
    try:
        # Auto-transcribe if prompt_text is empty
        if not prompt_text and prompt_text != "":
            print("Auto-transcribing reference audio...")
            prompt_text = transcribe(prompt_audio)
            print(f"Transcribed: {prompt_text}")
        
        start_time = time.time()
        
        # Configure parameters based on mode
        if mode == "Student Only (4 steps)":
            teacher_steps = 0
            student_start_step = 0
            teacher_stopping_time = 1.0
        elif mode == "Teacher-Guided (8 steps)":
            # Default configuration from the notebook
            teacher_steps = 16
            teacher_stopping_time = 0.07
            student_start_step = 1
        elif mode == "High Diversity (16 steps)":
            teacher_steps = 24
            teacher_stopping_time = 0.3
            student_start_step = 2
        else:  # Custom
            teacher_steps = custom_teacher_steps
            teacher_stopping_time = custom_teacher_stopping_time
            student_start_step = custom_student_start_step
        
        # Generate speech
        generated_audio = model.generate(
            gen_text=target_text,
            audio_path=prompt_audio,
            prompt_text=prompt_text if prompt_text else None,
            teacher_steps=teacher_steps,
            teacher_stopping_time=teacher_stopping_time,
            student_start_step=student_start_step,
            temperature=temperature,
            verbose=verbose
        )
        
        end_time = time.time()
        
        # Calculate metrics
        processing_time = end_time - start_time
        audio_duration = generated_audio.shape[-1] / 24000
        rtf = processing_time / audio_duration
        
        # Save audio
        with tempfile.NamedTemporaryFile(delete=False, suffix=".wav") as tmp_file:
            output_path = tmp_file.name
            
        if isinstance(generated_audio, np.ndarray):
            generated_audio = torch.from_numpy(generated_audio)
        
        if generated_audio.dim() == 1:
            generated_audio = generated_audio.unsqueeze(0)
            
        torchaudio.save(output_path, generated_audio, 24000)
        
        # Format metrics
        metrics = f"RTF: {rtf:.2f}x ({1/rtf:.2f}x speed) | Processing: {processing_time:.2f}s for {audio_duration:.2f}s audio"
        
        return output_path, "Success!", metrics, f"Mode: {mode} | Transcribed: {prompt_text[:50]}..." if not prompt_text else f"Mode: {mode}"
        
    except Exception as e:
        return None, f"Error: {str(e)}", "", ""

# Create Gradio interface
with gr.Blocks(title="DMOSpeech 2 - Zero-Shot TTS", theme=gr.themes.Soft()) as demo:
    gr.Markdown(f"""
    # 🎙️ DMOSpeech 2: Zero-Shot Text-to-Speech
    
    Generate natural speech in any voice with just a short reference audio!
    
    **Model Status:** {status_message} | **Device:** {device.upper()} | **ASR:** {"✅ Ready" if asr_pipe else "❌ Not available"}
    """)
    
    with gr.Row():
        with gr.Column(scale=1):
            # Reference audio input
            prompt_audio = gr.Audio(
                label="📎 Reference Audio",
                type="filepath",
                sources=["upload", "microphone"]
            )
            
            prompt_text = gr.Textbox(
                label="📝 Reference Text (leave empty for auto-transcription)",
                placeholder="The text spoken in the reference audio...",
                lines=2
            )
            
            target_text = gr.Textbox(
                label="✍️ Text to Generate",
                placeholder="Enter the text you want to synthesize...",
                lines=4
            )
            
            # Generation mode
            mode = gr.Radio(
                choices=[
                    "Student Only (4 steps)",
                    "Teacher-Guided (8 steps)",
                    "High Diversity (16 steps)",
                    "Custom"
                ],
                value="Teacher-Guided (8 steps)",
                label="🚀 Generation Mode",
                info="Choose speed vs quality/diversity tradeoff"
            )
            
            # Advanced settings (collapsible)
            with gr.Accordion("⚙️ Advanced Settings", open=False):
                temperature = gr.Slider(
                    minimum=0.0,
                    maximum=2.0,
                    value=0.0,
                    step=0.1,
                    label="Duration Temperature",
                    info="0 = deterministic, >0 = more variation in speech rhythm"
                )
                
                with gr.Group(visible=False) as custom_settings:
                    gr.Markdown("### Custom Mode Settings")
                    custom_teacher_steps = gr.Slider(
                        minimum=0,
                        maximum=32,
                        value=16,
                        step=1,
                        label="Teacher Steps",
                        info="More steps = higher quality"
                    )
                    
                    custom_teacher_stopping_time = gr.Slider(
                        minimum=0.0,
                        maximum=1.0,
                        value=0.07,
                        step=0.01,
                        label="Teacher Stopping Time",
                        info="When to switch to student"
                    )
                    
                    custom_student_start_step = gr.Slider(
                        minimum=0,
                        maximum=4,
                        value=1,
                        step=1,
                        label="Student Start Step",
                        info="Which student step to start from"
                    )
                
                verbose = gr.Checkbox(
                    value=False,
                    label="Verbose Output",
                    info="Show detailed generation steps"
                )
            
            generate_btn = gr.Button("🎵 Generate Speech", variant="primary", size="lg")
            
        with gr.Column(scale=1):
            # Output
            output_audio = gr.Audio(
                label="🔊 Generated Speech",
                type="filepath",
                autoplay=True
            )
            
            status = gr.Textbox(
                label="Status",
                interactive=False
            )
            
            metrics = gr.Textbox(
                label="Performance Metrics",
                interactive=False
            )
            
            info = gr.Textbox(
                label="Generation Info",
                interactive=False
            )
            
            # Tips
            gr.Markdown("""
            ### 💡 Quick Tips:
            
            - **Auto-transcription**: Leave reference text empty to auto-transcribe
            - **Student Only**: Fastest (4 steps), good quality
            - **Teacher-Guided**: Best balance (8 steps), recommended
            - **High Diversity**: More natural prosody (16 steps)
            - **Custom Mode**: Fine-tune all parameters
            
            ### 📊 Expected RTF (Real-Time Factor):
            - Student Only: ~0.05x (20x faster than real-time)
            - Teacher-Guided: ~0.10x (10x faster)
            - High Diversity: ~0.20x (5x faster)
            """)
    
    # Event handler
    generate_btn.click(
        generate_speech,
        inputs=[
            prompt_audio,
            prompt_text,
            target_text,
            mode,
            temperature,
            custom_teacher_steps,
            custom_teacher_stopping_time,
            custom_student_start_step,
            verbose
        ],
        outputs=[output_audio, status, metrics, info]
    )
    
    # Update visibility of custom settings based on mode
    def update_custom_visibility(mode):
        is_custom = (mode == "Custom")
        return gr.update(visible=is_custom)
    
    mode.change(
        update_custom_visibility,
        inputs=[mode],
        outputs=[custom_settings]
    )

# Launch the app
if __name__ == "__main__":
    if not model_loaded:
        print(f"Warning: Model failed to load - {status_message}")
    if not asr_pipe:
        print("Warning: ASR pipeline not available - auto-transcription disabled")
    
    demo.launch()