diff --git a/roop/core.py b/roop/core.py
index e685a60..79350a6 100755
--- a/roop/core.py
+++ b/roop/core.py
@@ -126,6 +126,23 @@ def get_video_frame(video_path, frame_number = 1):
     cap.release()
 
 
+def update_slider(video_path):
+    return lambda frame_number: preview.update(get_video_frame(video_path, frame_number))
+
+
+def process_test_preview(video_path):
+    test_frame = process_faces(
+        get_face_single(cv2.imread(args['source_img'])), 
+        get_video_frame(video_path, preview.current_frame.get()),
+        None
+    )
+    preview.update(test_frame)
+
+
+def preview_handler(video_path):
+    return lambda: preview_thread(process_test_preview(video_path))
+
+
 def preview_video(video_path):
     cap = cv2.VideoCapture(video_path)
     if not cap.isOpened():
@@ -146,22 +163,8 @@ def preview_video(video_path):
         # Preview
         preview.update(frame)
         amount_of_frames = cap.get(cv2.CAP_PROP_FRAME_COUNT)
-        
-        def update_slider(frame_number):
-            preview.update(get_video_frame(video_path, frame_number))
-
-        preview.init_slider(amount_of_frames, update_slider)
-
-        def test_handler():
-            test_frame = process_faces(
-                get_face_single(cv2.imread(args['source_img'])), 
-                get_video_frame(video_path, preview.current_frame.get()),
-                None,
-                roop.globals.all_faces
-            )
-            preview.update(test_frame)
-            
-        preview.set_test_handler(lambda: preview_thread(test_handler))
+        preview.init_slider(amount_of_frames, update_slider(video_path))
+        preview.set_preview_handler(preview_handler(video_path))
 
     cap.release()
 
diff --git a/roop/swapper.py b/roop/swapper.py
index 0ca8544..20294cf 100644
--- a/roop/swapper.py
+++ b/roop/swapper.py
@@ -29,9 +29,9 @@ def swap_face_in_frame(source_face, target_face, frame):
     return frame
 
 
-def process_faces(source_face, frame, progress, all_faces=False):
+def process_faces(source_face, frame, progress):
     progress_status = 'S'
-    if all_faces:
+    if roop.globals.all_faces:
         many_faces = get_face_many(frame)
         if many_faces:
             for face in many_faces:
@@ -56,7 +56,7 @@ def process_video(source_img, frame_paths, preview_callback):
         for frame_path in frame_paths:
             frame = cv2.imread(frame_path)
             try:
-                result = process_faces(source_face, frame, progress, roop.globals.all_faces)
+                result = process_faces(source_face, frame, progress)
                 cv2.imwrite(frame_path, result)
                 if preview_callback:
                     preview_callback(cv2.cvtColor(result, cv2.COLOR_BGR2RGB))                
diff --git a/roop/ui.py b/roop/ui.py
index c257c64..399878f 100644
--- a/roop/ui.py
+++ b/roop/ui.py
@@ -50,7 +50,7 @@ class PreviewWindow:
     def slider_changed(self, event):
         self.frame_change(self.frame_slider.get())
 
-    def set_test_handler(self, test_handler):
+    def set_preview_handler(self, test_handler):
         self.test_button.config(command = test_handler)
 
     # Show the window