Update app.py

app.py

@@ -173,7 +173,9 @@ async def download_file_from_url(url: str, retries: int = 3, delay: float = 2.0)
             temp_file = tempfile.NamedTemporaryFile(delete=False, suffix=".wav")
             temp_file.write(response.content)
             temp_file.close()
-
+            
+            print(f"{url} is downloaded and saved in cache")
+            
             download_cache[url] = temp_file.name
             return temp_file.name
 
@@ -263,19 +265,27 @@ async def generate_story_audios(story: StoryCreationDTO, base_output: str):
 
 from pydub import AudioSegment
 import os
+import subprocess
 
 def ensure_wav(file_path: str) -> str:
     """
-    Convert an MP3 (or other non-WAV) file to WAV.
-    Returns path to WAV file.
-    If already WAV, returns original path.
+    Convert a single audio file to WAV using ffmpeg.
+    Returns the path to the WAV file.
+    If the file is already WAV, returns the original path.
     """
     ext = os.path.splitext(file_path)[1].lower()
-    if ext != ".wav":
-        wav_path = file_path.rsplit(".", 1)[0] + ".wav"
-        AudioSegment.from_file(file_path).export(wav_path, format="wav")
-        return wav_path
-    return file_path
+    
+    if ext == ".wav":
+        return file_path  # Already WAV
+    
+    # Output path: same folder, same name, .wav extension
+    wav_path = os.path.splitext(file_path)[0] + ".wav"
+    
+    # Run ffmpeg conversion
+    subprocess.run(["ffmpeg", "-y", "-i", file_path, wav_path], check=True)
+    
+    print(f"Converted: {file_path} → {wav_path}")
+    return wav_path
 
 from pydub import AudioSegment
 import asyncio