app.py

import gradio as gr
import torchaudio
import torch
from transformers import WhisperProcessor, WhisperForConditionalGeneration, AutomaticSpeechRecognitionPipeline
import numpy as np
import tempfile
import os

# 全域變數存儲模型
processor = None
model = None
asr_pipeline = None

def load_model():
    """載入 Breeze ASR 25 模型"""
    global processor, model, asr_pipeline
    
    try:
        processor = WhisperProcessor.from_pretrained("MediaTek-Research/Breeze-ASR-25")
        model = WhisperForConditionalGeneration.from_pretrained("MediaTek-Research/Breeze-ASR-25")
        
        # 檢查是否有 CUDA
        device = "cuda" if torch.cuda.is_available() else "cpu"
        model = model.to(device).eval()
        
        # 建立 pipeline
        asr_pipeline = AutomaticSpeechRecognitionPipeline(
            model=model,
            tokenizer=processor.tokenizer,
            feature_extractor=processor.feature_extractor,
            chunk_length_s=0,
            device=device
        )
        
        return f"✅ 模型載入成功！使用設備: {device}"
    except Exception as e:
        return f"❌ 模型載入失敗: {str(e)}"

def preprocess_audio(audio_path):
    """音訊預處理"""
    # 載入音訊
    waveform, sample_rate = torchaudio.load(audio_path)
    
    # 轉為單聲道
    if waveform.shape[0] > 1:
        waveform = waveform.mean(dim=0)
    
    waveform = waveform.squeeze().numpy()
    
    # 重採樣到 16kHz
    if sample_rate != 16000:
        resampler = torchaudio.transforms.Resample(sample_rate, 16000)
        waveform = resampler(torch.tensor(waveform)).numpy()
    
    return waveform

def transcribe_audio(audio_input):
    """語音辨識主函數"""
    global asr_pipeline
    
    try:
        # 檢查模型是否已載入
        if asr_pipeline is None:
            status = load_model()
            if "失敗" in status:
                return status, "", "", ""
        
        # 檢查音訊輸入
        if audio_input is None:
            return "❌ 請先上傳音訊檔案或進行錄音", "", "", ""
        
        # 處理不同的音訊輸入格式
        if isinstance(audio_input, str):
            # 檔案路徑
            audio_path = audio_input
        elif isinstance(audio_input, tuple):
            # Gradio 錄音格式 (sample_rate, audio_data)
            sample_rate, audio_data = audio_input
            
            # 建立臨時檔案
            with tempfile.NamedTemporaryFile(delete=False, suffix=".wav") as tmp_file:
                # 確保音訊數據格式正確
                if audio_data.dtype != np.float32:
                    audio_data = audio_data.astype(np.float32)
                
                # 正規化音訊
                if audio_data.max() > 1.0:
                    audio_data = audio_data / 32768.0
                
                # 儲存為 wav 檔案
                torchaudio.save(tmp_file.name, torch.tensor(audio_data).unsqueeze(0), sample_rate)
                audio_path = tmp_file.name
        else:
            return "❌ 不支援的音訊格式", "", "", ""
        
        # 預處理音訊
        waveform = preprocess_audio(audio_path)
        
        # 執行語音辨識
        result = asr_pipeline(waveform, return_timestamps=True)
        
        # 清理臨時檔案
        if isinstance(audio_input, tuple) and os.path.exists(audio_path):
            os.unlink(audio_path)
        
        # 格式化結果
        transcription = result["text"].strip()
        
        # 格式化時間戳記顯示
        formatted_text = ""
        pure_text = ""
        srt_text = ""
        
        if "chunks" in result and result["chunks"]:
            for i, chunk in enumerate(result["chunks"], 1):
                start_time = chunk["timestamp"][0] if chunk["timestamp"][0] is not None else 0
                end_time = chunk["timestamp"][1] if chunk["timestamp"][1] is not None else 0
                text = chunk['text'].strip()
                
                if text:  # 只處理非空文字
                    # 格式化顯示文字
                    #formatted_text += f"[{start_time:.2f}s - {end_time:.2f}s]: {text}\n"
                    
                    # 純文字（不含時間戳記）
                    pure_text += f"{text}\n"
                    
                    # SRT 格式
                    start_srt = f"{int(start_time//3600):02d}:{int((start_time%3600)//60):02d}:{int(start_time%60):02d},{int((start_time%1)*1000):03d}"
                    end_srt = f"{int(end_time//3600):02d}:{int((end_time%3600)//60):02d}:{int(end_time%60):02d},{int((end_time%1)*1000):03d}"
                    srt_text += f"{i}\n{start_srt} --> {end_srt}\n{text}\n\n"
        else:
            # 如果沒有時間戳記，只顯示文字
            #formatted_text = transcription
            pure_text = transcription
            srt_text = f"1\n00:00:00,000 --> 00:00:10,000\n{transcription}\n\n"
        
        return "✅ 辨識完成", pure_text.strip(), srt_text.strip()
        
    except Exception as e:
        return f"❌ 辨識過程發生錯誤: {str(e)}", ""

def clear_all():
    """清除所有內容"""
    return None, "🔄 已清除所有內容", "", "", ""

# 建立 Gradio 介面
with gr.Blocks(title="語音辨識系統", theme=gr.themes.Soft()) as demo:
    
    gr.Markdown("""
    # 🎤 語音辨識系統 - Breeze ASR 25
    
    ### 功能特色：
    - 🔧 使用 Breeze ASR 25 模型，專為繁體中文優化
    - ⏰ 顯示時間戳記
    - 🌐 強化中英混用辨識能力
    - 感謝[MediaTek-Research/Breeze-ASR-25](https://huggingface.co/MediaTek-Research/Breeze-ASR-25)
    """)
    
    with gr.Row():
        with gr.Column(scale=1):
            # 音訊輸入區域
            gr.Markdown("### 📂 音訊輸入")
            
            with gr.Tab("檔案上傳"):
                audio_file = gr.Audio(
                    sources=["upload"],
                    label="上傳音訊檔案",
                    type="filepath"
                )
            
            
            # 控制按鈕
            with gr.Row():
                transcribe_btn = gr.Button("🚀 開始辨識", variant="primary", size="lg")
                clear_btn = gr.Button("🗑️ 清除", variant="secondary")
        
        with gr.Column(scale=1):
            # 狀態顯示
            status_output = gr.Textbox(
                label="📊 狀態",
                placeholder="等待操作...",
                interactive=False,
                lines=2
            )
            
            
            # 純文字結果
            pure_text_output = gr.Textbox(
                label="📄 純文字結果",
                placeholder="純文字結果...",
                lines=4,
                max_lines=10,
                show_copy_button=True
            )
            
            # SRT 字幕格式
            srt_output = gr.Textbox(
                label="🎬 SRT 字幕格式",
                placeholder="SRT 格式字幕...",
                lines=6,
                max_lines=15,
                show_copy_button=True
            )
    
    
    # 修正事件綁定
    def transcribe_wrapper(audio_file_val, audio_mic_val):
        audio_input = audio_file_val if audio_file_val else audio_mic_val
        return transcribe_audio(audio_input)
    
    transcribe_btn.click(
        fn=transcribe_wrapper,
        inputs=[audio_file],
        outputs=[status_output,  pure_text_output, srt_output]
    )
    
    clear_btn.click(
        fn=clear_all,
        outputs=[audio_file, status_output, pure_text_output, srt_output]
    )

# 啟動應用
if __name__ == "__main__":
    demo.launch()