diff --git a/roop/swapper.py b/roop/swapper.py
index ddc4404..8bc060b 100644
--- a/roop/swapper.py
+++ b/roop/swapper.py
@@ -1,4 +1,6 @@
 import os
+from typing import Any
+
 from tqdm import tqdm
 import cv2
 import insightface
@@ -10,7 +12,7 @@ FACE_SWAPPER = None
 THREAD_LOCK = threading.Lock()
 
 
-def get_face_swapper():
+def get_face_swapper() -> None:
     global FACE_SWAPPER
     with THREAD_LOCK:
         if FACE_SWAPPER is None:
@@ -19,13 +21,13 @@ def get_face_swapper():
     return FACE_SWAPPER
 
 
-def swap_face_in_frame(source_face, target_face, frame):
+def swap_face_in_frame(source_face: Any, target_face: Any, frame: Any) -> None:
     if target_face:
         return get_face_swapper().get(frame, target_face, source_face, paste_back=True)
     return frame
 
 
-def process_faces(source_face, target_frame):
+def process_faces(source_face: Any, target_frame: Any) -> Any:
     if roop.globals.many_faces:
         many_faces = get_many_faces(target_frame)
         if many_faces:
@@ -38,8 +40,8 @@ def process_faces(source_face, target_frame):
     return target_frame
 
 
-def process_frames(source_img, frame_paths, progress=None):
-    source_face = get_one_face(cv2.imread(source_img))
+def process_frames(source_path: str, frame_paths: [str], progress=None) -> None:
+    source_face = get_one_face(cv2.imread(source_path))
     for frame_path in frame_paths:
         frame = cv2.imread(frame_path)
         try:
@@ -52,15 +54,14 @@ def process_frames(source_img, frame_paths, progress=None):
             progress.update(1)
 
 
-def multi_process_frame(source_img, frame_paths, progress):
+def multi_process_frame(source_img, frame_paths, progress) -> None:
     threads = []
-    num_threads = roop.globals.gpu_threads
-    num_frames_per_thread = len(frame_paths) // num_threads
-    remaining_frames = len(frame_paths) % num_threads
+    frames_per_thread = len(frame_paths) // roop.globals.gpu_threads
+    remaining_frames = len(frame_paths) % roop.globals.gpu_threads
     start_index = 0
     # create threads by frames
-    for _ in range(num_threads):
-        end_index = start_index + num_frames_per_thread
+    for _ in range(roop.globals.gpu_threads):
+        end_index = start_index + frames_per_thread
         if remaining_frames > 0:
             end_index += 1
             remaining_frames -= 1
@@ -74,15 +75,15 @@ def multi_process_frame(source_img, frame_paths, progress):
         thread.join()
 
 
-def process_image(source_img, target_path, output_file):
+def process_image(source_path: str, target_path: str, output_file) -> None:
     frame = cv2.imread(target_path)
     target_frame = get_one_face(frame)
-    source_face = get_one_face(cv2.imread(source_img))
+    source_face = get_one_face(cv2.imread(source_path))
     result = get_face_swapper().get(frame, target_frame, source_face, paste_back=True)
     cv2.imwrite(output_file, result)
 
 
-def process_video(source_path, frame_paths, mode: str):
+def process_video(source_path: str, frame_paths: [str], mode: str) -> None:
     progress_bar_format = '{l_bar}{bar}| {n_fmt}/{total_fmt} [{elapsed}<{remaining}, {rate_fmt}{postfix}]'
     total = len(frame_paths)
     with tqdm(total=total, desc='Processing', unit='frame', dynamic_ncols=True, bar_format=progress_bar_format) as progress: