Update app.py

app.py

@@ -76,18 +76,15 @@ def download_audio(video_url, quality: str = '128', speed: float = None):
         'format': 'bestaudio/best',
         'outtmpl': '%(title)s.%(ext)s',
         'quiet': True,
-        'postprocessors': [{
-            'key': 'FFmpegExtractAudio',
-            'preferredcodec': 'mp3', #'opus',
-            'preferredquality': quality,
-        }]
     }
 
     if speed:
-        ydl_opts['postprocessors'].append({
-            'key': 'FFmpegFilter',
-            'filter_complex': f"atempo={speed}"
-        })
+        ydl_opts["postprocessors"] = [{
+            "key": "FFmpegExtractAudio",
+            "preferredcodec": "mp3",
+            "preferredquality": quality,
+            "addopts": f"-filter:a \"atempo={speed}\"",
+        }]
 
     with yt_dlp.YoutubeDL(ydl_opts) as ydl:
         ydl.download([video_url])