diff --git a/src/engines/core/base_engine.py b/src/engines/core/base_engine.py
index cfff998..45e8575 100644
--- a/src/engines/core/base_engine.py
+++ b/src/engines/core/base_engine.py
@@ -47,7 +47,7 @@ class BaseRenderEngine(object):
     def worker_class():  # override when subclassing to link worker class
         raise NotImplementedError("Worker class not implemented")
 
-    def get_help(self):
+    def get_help(self):  # override if renderer uses different help flag
         path = self.renderer_path()
         if not path:
             raise FileNotFoundError("renderer path not found")
@@ -56,7 +56,7 @@ class BaseRenderEngine(object):
         return help_doc
 
     def get_project_info(self, project_path, timeout=10):
-        raise NotImplementedError(f"get_project_info not implemented for {cls.__name__}")
+        raise NotImplementedError(f"get_project_info not implemented for {self.__name__}")
 
     @classmethod
     def get_output_formats(cls):
@@ -66,6 +66,9 @@ class BaseRenderEngine(object):
     def get_arguments(cls):
         pass
 
+    def get_options(self):  # override to return options for ui
+        return {}
+
     def perform_presubmission_tasks(self, project_path):
         return project_path
 
diff --git a/src/engines/ffmpeg/ffmpeg_worker.py b/src/engines/ffmpeg/ffmpeg_worker.py
index 687d35b..b7780fd 100644
--- a/src/engines/ffmpeg/ffmpeg_worker.py
+++ b/src/engines/ffmpeg/ffmpeg_worker.py
@@ -10,15 +10,9 @@ class FFMPEGRenderWorker(BaseRenderWorker):
 
     engine = FFMPEG
 
-    def __init__(self, input_path, output_path, args=None, parent=None, name=None):
-        super(FFMPEGRenderWorker, self).__init__(input_path=input_path, output_path=output_path, args=args,
-                                                 parent=parent, name=name)
-
-        stream_info = subprocess.check_output([self.renderer_path, "-i",  # https://stackoverflow.com/a/61604105
-                                               input_path, "-map", "0:v:0", "-c", "copy", "-f", "null", "-y",
-                                                     "/dev/null"], stderr=subprocess.STDOUT).decode('utf-8')
-        found_frames = re.findall('frame=\s*(\d+)', stream_info)
-        self.project_length = found_frames[-1] if found_frames else '-1'
+    def __init__(self, input_path, output_path, engine_path, args=None, parent=None, name=None):
+        super(FFMPEGRenderWorker, self).__init__(input_path=input_path, output_path=output_path,
+                                                 engine_path=engine_path, args=args, parent=parent, name=name)
         self.current_frame = -1
 
     def generate_worker_subprocess(self):