fix: try to fix shell execute problem

src/mp4.py

@@ -197,7 +197,7 @@ async def write_metadata(song: bytes, metadata: SongMetadata, embed_metadata: li
     subprocess.run(["mp4box", "-time", time, "-mtime", time, "-name", f"1={metadata.title}", "-itags",
                     ":".join(["tool=", f"cover={absolute_cover_path}",
                               metadata.to_itags_params(embed_metadata)]),
-                    song_name.absolute()], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, shell=if_shell())
+                    song_name.absolute()], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
     with open(song_name.absolute(), "rb") as f:
         embed_song = f.read()
     tmp_dir.cleanup()
@@ -214,8 +214,9 @@ async def fix_encapsulate(song: bytes) -> bytes:
     new_song_name = Path(tmp_dir.name) / Path(f"{name}_fixed.m4a")
     with open(song_name.absolute(), "wb") as f:
         f.write(song)
-    subprocess.run(["ffmpeg", "-y", "-i", song_name.absolute(), "-fflags", "+bitexact", "-c:a", "copy", "-c:v", "copy",
-                    new_song_name.absolute()], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, shell=if_shell())
+    subprocess.run(
+        f"ffmpeg -y -i {song_name.absolute()} -fflags +bitexact -c:a copy -c:v copy {new_song_name.absolute()}",
+        stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, shell=if_shell())
     with open(new_song_name.absolute(), "rb") as f:
         encapsulated_song = f.read()
     tmp_dir.cleanup()