limit thread count to improve performance

utils/job.py

@@ -0,0 +1,23 @@
+import os, subprocess, threading, time
+
+def _job(file_path, file_name, arguments, output_path):
+    os.system(f"echo {file_name} started")
+
+    subprocess.run(['ffmpeg','-i', os.path.join(file_path, file_name),
+                    '-v', '0', *arguments,
+                    f'{output_path}\{file_name}.mp4'])
+
+    os.system(f"echo {file_name} finished")
+
+def make_job(files_list, file_path, arguments, output_path):
+    job_list = []
+    for file_name in files_list:
+        job_list.append(threading.Thread(target=_job, args=(file_path, file_name, arguments, output_path)))
+    return job_list
+
+def do_job(job_list):
+    for job in job_list:
+        while threading.active_count() > 4: pass
+        else:
+            job.start()
+    pass