remove '_kill' method

ffmpeger.py

@@ -65,12 +65,10 @@ class FFmpeg:
                '\tDownload and extract archive from: https://evermeet.cx/ffmpeg/\n'
                '\tTarget: /usr/bin/ffmpeg\n')
         if not path_ffmpeg:
-            if platform.startswith('linux'):
+            if platform.startswith('linux') or platform.startswith('darwin'):
                 path_ffmpeg = '/usr/bin/ffmpeg'
             elif platform.startswith('win32'):
                 path_ffmpeg = environ['PROGRAMFILES'] + "\\ffmpeg\\bin\\ffmpeg.exe"
-            elif platform.startswith('darwin'):
-                path_ffmpeg = '/usr/bin/ffmpeg'
         if path.exists(path_ffmpeg):
             return path_ffmpeg
         else:
@@ -164,25 +162,11 @@ class FFmpeg:
                     print(que.get())
                 sleep(sec)
                 if que.empty():
-                    cls._kill(pid)
+                    Proc.kill(pid)
                     print('exit by watchdog')
                     break
             exit()
 
-    @classmethod
-    def _kill(cls, pid: int):
-        """
-        Kill the process by means of the OS
-        :param pid: process ID
-        :return: None
-        """
-        if platform.startswith('linux'):
-            Popen(['kill', '-s', 'SIGKILL', str(pid)])
-        elif platform.startswith('win32'):
-            Popen(['taskkill', '/PID', str(pid), '/F'])
-        elif platform.startswith('darwin'):
-            Popen(['kill', '-s', 'SIGKILL', str(pid)])
-
 
 if __name__ == "__main__":
     from argparse import ArgumentParser