Ability to set custom start / end frames (#14)

* Accept start / end frames in job submissions. Start / end frame support for Blender

* Remove old render_all_frames variables and misc cleanup

* Client work - Client determines frame count for FFMPEG and shows frame picker UI

lib/workers/base_worker.py

@@ -48,7 +48,9 @@ class BaseRenderWorker(Base):
     renderer = Column(String)
     renderer_version = Column(String)
     priority = Column(Integer)
-    total_frames = Column(Integer)
+    project_length = Column(Integer)
+    start_frame = Column(Integer)
+    end_frame = Column(Integer, nullable=True)
     owner = Column(String)
     client = Column(String)
     name = Column(String)
@@ -86,8 +88,10 @@ class BaseRenderWorker(Base):
         self.name = name
 
         # Frame Ranges
-        self.total_frames = 0
-        self.current_frame = 0
+        self.project_length = -1
+        self.current_frame = 0  # should this be a 1 ?
+        self.start_frame = 0  # should this be a 1 ?
+        self.end_frame = None
 
         # Logging
         self.start_time = None
@@ -107,6 +111,10 @@ class BaseRenderWorker(Base):
         self.is_finished = False
         self.last_output = None
 
+    @property
+    def total_frames(self):
+        return (self.end_frame or self.project_length) - self.start_frame + 1
+
     @property
     def status(self):
         return self._status
@@ -119,6 +127,7 @@ class BaseRenderWorker(Base):
     def status(self):
         if self._status in [RenderStatus.RUNNING.value, RenderStatus.NOT_STARTED.value]:
             if not hasattr(self, 'errors'):
+                self._status = RenderStatus.CANCELLED
                 return RenderStatus.CANCELLED
         return string_to_status(self._status)
 
@@ -129,7 +138,7 @@ class BaseRenderWorker(Base):
 
     def generate_subprocess(self):
         # Convert raw args from string if available and catch conflicts
-        generated_args = self.generate_worker_subprocess()
+        generated_args = [str(x) for x in self.generate_worker_subprocess()]
         generated_args_flags = [x for x in generated_args if x.startswith('-')]
         if len(generated_args_flags) != len(set(generated_args_flags)):
             msg = "Cannot generate subprocess - Multiple arg conflicts detected"
@@ -175,7 +184,7 @@ class BaseRenderWorker(Base):
             return
 
         self.status = RenderStatus.RUNNING
-        logger.info(f'Starting {self.engine.name()} {self.engine.version()} Render for {self.input_path}')
+        logger.info(f'Starting {self.engine.name()} {self.engine.version()} Render for {self.input_path} | Frame Count: {self.total_frames}')
         self.__thread.start()
 
     def run(self):