diff --git a/modules/processors/frame/face_swapper.py b/modules/processors/frame/face_swapper.py
index f38046d..cea0b59 100644
--- a/modules/processors/frame/face_swapper.py
+++ b/modules/processors/frame/face_swapper.py
@@ -263,13 +263,16 @@ STREAM_SOURCE_FACE = None
 
 def process_frame_stream(source_path: str, frame: Frame) -> Frame:
     global STREAM_SOURCE_FACE
-    if not modules.globals.map_faces:
-        if STREAM_SOURCE_FACE is None:
-            source_img = cv2.imread(source_path)
-            if source_img is not None:
-                STREAM_SOURCE_FACE = get_one_face(source_img)
-        if STREAM_SOURCE_FACE is not None:
-            return process_frame(STREAM_SOURCE_FACE, frame)
-        return frame
-    else:
-        return process_frame_v2(frame)
+    if modules.globals.map_faces:
+        result = process_frame_v2(frame)
+        if result is not None:
+            return result
+        else:
+            return frame  # Fallback to original frame if process_frame_v2 returns None
+    if STREAM_SOURCE_FACE is None:
+        source_img = cv2.imread(source_path)
+        if source_img is not None:
+            STREAM_SOURCE_FACE = get_one_face(source_img)
+    if STREAM_SOURCE_FACE is not None:
+        return process_frame(STREAM_SOURCE_FACE, frame)
+    return frame
diff --git a/modules/utilities.py b/modules/utilities.py
index 13bc93b..a146b20 100644
--- a/modules/utilities.py
+++ b/modules/utilities.py
@@ -39,13 +39,14 @@ def run_ffmpeg(args: List[str]) -> bool:
 
 
 def start_ffmpeg_writer(width: int, height: int, fps: float, output_path: str) -> subprocess.Popen:
+    # Pass all arguments as a list to avoid shell injection
     commands = [
         "ffmpeg",
         "-hide_banner",
         "-hwaccel",
         "auto",
         "-loglevel",
-        modules.globals.log_level,
+        str(modules.globals.log_level),
         "-f",
         "rawvideo",
         "-pix_fmt",
@@ -57,7 +58,7 @@ def start_ffmpeg_writer(width: int, height: int, fps: float, output_path: str) -
         "-i",
         "-",
         "-c:v",
-        modules.globals.video_encoder,
+        str(modules.globals.video_encoder),
         "-crf",
         str(modules.globals.video_quality),
         "-pix_fmt",
@@ -65,7 +66,7 @@ def start_ffmpeg_writer(width: int, height: int, fps: float, output_path: str) -
         "-vf",
         "colorspace=bt709:iall=bt601-6-625:fast=1",
         "-y",
-        output_path,
+        str(output_path),
     ]
     return subprocess.Popen(commands, stdin=subprocess.PIPE)