fix ffmpeg args

hls_download.py

@@ -16,9 +16,9 @@ def download_clips(stream_url, out_dir, start_time, end_time, resize=True):
         'no_warnings': True,
         'external_downloader': 'ffmpeg',
         'external_downloader_args': [
-            'ffmpeg_i', 
-            f'-ss {max(0, start_time - 2)}',  # Start 2 seconds earlier, but not before 0
-            f'-t {duration}'  # Download only the duration we need
+            'ffmpeg_i:', 
+            f'-ss {max(0, start_time - 2)}',
+            '-t', f'{duration}'
         ],
     }