Added audio preview.

Author: CoffeeMethod

gui.py

@@ -1,6 +1,8 @@
 import os
 import time
 import json
+import re
+import winsound
 import customtkinter as ctk
 from tkinter import filedialog, messagebox
 import threading
@@ -272,6 +274,9 @@ def create_widgets(self):
 
         btn_frame = ctk.CTkFrame(action_frame, fg_color="transparent")
         btn_frame.pack(fill="x", pady=10)
+
+        self.preview_btn = ctk.CTkButton(btn_frame, text="Preview Audio", command=self.preview_conversion, height=40, fg_color="#2B719E", hover_color="#205578")
+        self.preview_btn.pack(side="left", fill="x", expand=True, padx=5)
 
         self.start_btn = ctk.CTkButton(btn_frame, text="Start Generation", command=self.start_conversion, height=40, font=("Roboto", 14, "bold"))
         self.start_btn.pack(side="left", fill="x", expand=True, padx=5)
@@ -367,6 +372,7 @@ def set_ui_state(self, is_running):
         cancel_state = "normal" if is_running else "disabled"
 
         self.start_btn.configure(state=state)
+        self.preview_btn.configure(state=state)
         self.cancel_btn.configure(state=cancel_state)
         self.thread_minus_btn.configure(state=state)
         self.thread_plus_btn.configure(state=state)
@@ -375,6 +381,58 @@ def set_ui_state(self, is_running):
         if not is_running:
             self.progress_bar.set(0 if self.engine.cancel_event.is_set() else 1)
 
+    def preview_conversion(self):
+        # 1. Get Text
+        current_tab = self.tab_view.get()
+        text_data = ""
+        
+        if current_tab == "Direct Text":
+            text_data = self.text_entry.get("1.0", "end").strip()
+        else:
+            fpath = self.file_path_var.get()
+            if os.path.exists(fpath):
+                try:
+                    text_data = self.engine.extract_text_from_file(fpath)
+                except:
+                    pass
+        
+        if not text_data:
+            text_data = "This is a sample audio preview using the Koh-koh-ro TTS engine. It demonstrates the voice quality and speed settings."
+            
+        # Truncate to 2 sentences
+        sentences = re.split(r'(?<=[.!?])\s+', text_data)
+        preview_text = " ".join(sentences[:2])
+        if len(preview_text) > 500: # Safety cap
+             preview_text = preview_text[:500]
+             
+        # Config
+        voice = self.voice_var.get()
+        speed = self.speed_var.get()
+        
+        # Temp file
+        import tempfile
+        tmp_path = os.path.join(tempfile.gettempdir(), "kokoro_preview.wav")
+        
+        self.status_label.configure(text="Generating preview...", text_color="blue")
+        
+        def _on_preview_done(future):
+            def _ui_update():
+                try:
+                    success = future.result()
+                    if success:
+                        self.status_label.configure(text="Playing preview...", text_color="green")
+                        winsound.PlaySound(tmp_path, winsound.SND_FILENAME | winsound.SND_ASYNC)
+                        self.after(3000, lambda: self.status_label.configure(text="Ready", text_color="gray"))
+                    else:
+                        self.status_label.configure(text="Preview failed.", text_color="red")
+                except Exception as e:
+                    self.status_label.configure(text=f"Preview error: {e}", text_color="red")
+            
+            self.after(0, _ui_update)
+        
+        future = self.engine.worker.run_coro(self.engine.generate_preview(preview_text, voice, speed, tmp_path))
+        future.add_done_callback(_on_preview_done)
+
     def start_conversion(self):
         # 0. Validate Threads
         try:

kokoro_engine.py

@@ -5,6 +5,7 @@
 import concurrent.futures
 import soundfile as sf
 import torch
+import numpy as np
 import pypdf
 import ebooklib
 from ebooklib import epub
@@ -67,6 +68,36 @@ async def init_pipeline_async(self):
             if self.on_status: self.on_status(f"Pipeline Init Failed: {e}", True)
             return False
 
+    async def generate_preview(self, text, voice, speed, output_path):
+        def _gen():
+            if not self.pipeline:
+                # Try to use thread local if main pipeline not available, or init new
+                p = get_thread_pipeline()
+                if not p: return False
+            else:
+                p = self.pipeline
+
+            try:
+                # Generate
+                generator = p(text, voice=voice, speed=speed, split_pattern=r"\n+")
+                pieces = []
+                for _, _, audio in generator:
+                    if isinstance(audio, torch.Tensor):
+                        audio = audio.cpu().numpy()
+                    pieces.append(audio)
+                
+                if not pieces:
+                    return False
+                
+                full_audio = np.concatenate(pieces)
+                sf.write(output_path, full_audio, 24000)
+                return True
+            except Exception as e:
+                print(f"Preview error: {e}")
+                return False
+
+        return await asyncio.to_thread(_gen)
+
     def extract_text_from_file(self, fpath):
         if not os.path.exists(fpath):
             raise FileNotFoundError("File does not exist.")