Update app.py

app.py

@@ -72,7 +72,7 @@ def convert_video(use_youtube, youtube_url, video_file, downscale, faster, use_m
         downscaled_path = os.path.join(UPLOAD_FOLDER, f"downscaled_{uuid.uuid4()}.mp4")
         downscale_cmd = ['ffmpeg', '-hwaccel', accel, '-y', '-i', input_path,
                          '-vf', 'scale=144:-2', '-c:v', 'libx264', '-preset', 'ultrafast', '-crf', '40',
-                         '-an', downscaled_path]
+                         '-c:a', 'copy', downscaled_path]
         try:
             subprocess.run(downscale_cmd, check=True)
         except subprocess.CalledProcessError as e: