Update src/backend/generate_song_cover.py

src/backend/generate_song_cover.py

@@ -3,7 +3,13 @@ This module contains functions to generate song covers using RVC-based voice mod
 """
 
 from typing import Any
-from typings.extra import F0Method, InputAudioExt, InputType, OutputAudioExt
+from typing import Literal
+
+F0Method = Literal["rmvpe", "crepe", "mangio-crepe"]
+InputAudioExt = Literal["wav", "mp3", "aac", "m4a"]
+InputType = Literal["local", "yt"]
+OutputAudioExt = Literal["wav", "mp3", "aac"]
+
 
 import gc
 import glob