[cli] Fix type hints for some context fields

scenedetect/_cli/context.py

@@ -90,9 +90,9 @@ def __init__(self):
         self.video_stream: VideoStream = None
         self.load_scenes_input: str = None  # load-scenes -i/--input
         self.load_scenes_column_name: str = None  # load-scenes -c/--start-col-name
-        self.start_time: FrameTimecode = None  # time -s/--start
-        self.end_time: FrameTimecode = None  # time -e/--end
-        self.duration: FrameTimecode = None  # time -d/--duration
+        self.start_time: ty.Optional[FrameTimecode] = None  # time -s/--start
+        self.end_time: ty.Optional[FrameTimecode] = None  # time -e/--end
+        self.duration: ty.Optional[FrameTimecode] = None  # time -d/--duration
         self.frame_skip: int = None
 
         # Options:

scenedetect/_cli/controller.py

@@ -160,19 +160,16 @@ def _load_scenes(context: CliContext) -> ty.Tuple[SceneList, CutList]:
         csv_headers = next(file_reader)
         if context.load_scenes_column_name not in csv_headers:
             csv_headers = next(file_reader)
-        # Check to make sure column headers are present
+        # Check to make sure column headers are present and then load the data.
         if context.load_scenes_column_name not in csv_headers:
             raise ValueError("specified column header for scene start is not present")
-
         col_idx = csv_headers.index(context.load_scenes_column_name)
-
         cut_list = sorted(
             FrameTimecode(row[col_idx], fps=context.video_stream.frame_rate) - 1
             for row in file_reader
         )
-        # `SceneDetector` works on cuts, so we have to skip the first scene and use the first frame
-        # of the next scene as the cut point. This can be fixed if we used `SparseSceneDetector`
-        # but this part of the API is being reworked and hasn't been used by any detectors yet.
+        # `SceneDetector` works on cuts, so we have to skip the first scene and place the first
+        # cut point where the next scenes starts.
         if cut_list:
             cut_list = cut_list[1:]
 
@@ -182,14 +179,12 @@ def _load_scenes(context: CliContext) -> ty.Tuple[SceneList, CutList]:
             cut_list = [cut for cut in cut_list if cut > context.start_time]
 
         end_time = context.video_stream.duration
-        if context.end_time is not None or context.duration is not None:
-            if context.end_time is not None:
-                end_time = context.end_time
-            elif context.duration is not None:
-                end_time = start_time + context.duration
-            end_time = min(end_time, context.video_stream.duration)
+        if context.end_time is not None:
+            end_time = min(context.end_time, context.video_stream.duration)
+        elif context.duration is not None:
+            end_time = min(start_time + context.duration, context.video_stream.duration)
+
         cut_list = [cut for cut in cut_list if cut < end_time]
+        scene_list = get_scenes_from_cuts(cut_list=cut_list, start_pos=start_time, end_pos=end_time)
 
-        return get_scenes_from_cuts(
-            cut_list=cut_list, start_pos=start_time, end_pos=end_time
-        ), cut_list
+        return (scene_list, cut_list)