split-video: rename --expand-to-video to --expand, add cfg/docs

Addresses PR #551 review:
- Rename CLI flag --expand-to-video to --expand (terser form).
- Add `expand` entry to scenedetect.cfg template.
- Document --expand option in docs/cli.rst.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: charlesvestal

docs/cli.rst

@@ -857,6 +857,10 @@ Options
 
   Split video using mkvmerge. Faster than re-encoding, but less precise. If set, options other than :option:`-f/--filename <-f>`, :option:`-q/--quiet <-q>` and :option:`-o/--output <-o>` will be ignored. Note that mkvmerge automatically appends the $SCENE_NUMBER suffix.
 
+.. option:: --expand
+
+  Extend the first/last output clips to cover the full input video, even if the :ref:`time <command-time>` command's ``--start``/``--end`` limited the analysis window. Useful for keeping content outside the analyzed region attached to the adjacent split.
+
 
 .. _command-time:
 

scenedetect.cfg

@@ -206,6 +206,11 @@
 # Arguments to specify to ffmpeg for encoding. Quotes are not required.
 #args = -map 0:v:0 -map 0:a? -map 0:s? -c:v libx264 -preset veryfast -crf 22 -c:a aac
 
+# Extend the first/last output clips to cover the full input video, even if
+# `time -s/-e` limited the analysis window. Useful for keeping content outside
+# the analyzed region attached to the adjacent split.
+#expand = no
+
 
 [save-images]
 # Folder to output videos. Overrides [global] output option.

scenedetect/_cli/__init__.py

@@ -1295,12 +1295,12 @@ def list_scenes_command(
     ),
 )
 @click.option(
-    "--expand-to-video",
+    "--expand",
     is_flag=True,
     flag_value=True,
     default=False,
     help="Extend the first/last output clips to cover the full input video, even if `time -s/-e` limited the analysis window. Useful for keeping content outside the analyzed region attached to the adjacent split.{}".format(
-        USER_CONFIG.get_help_string("split-video", "expand-to-video")
+        USER_CONFIG.get_help_string("split-video", "expand")
     ),
 )
 @click.pass_context
@@ -1315,7 +1315,7 @@ def split_video_command(
     preset: str | None,
     args: str | None,
     mkvmerge: bool,
-    expand_to_video: bool,
+    expand: bool,
 ):
     ctx = ctx.obj
     assert isinstance(ctx, CliContext)
@@ -1382,7 +1382,7 @@ def split_video_command(
         "output": ctx.config.get_value("split-video", "output", output),
         "show_output": not ctx.config.get_value("split-video", "quiet", quiet),
         "ffmpeg_args": args,
-        "expand_to_video": ctx.config.get_value("split-video", "expand-to-video", expand_to_video),
+        "expand": ctx.config.get_value("split-video", "expand", expand),
     }
     ctx.add_command(cli_commands.split_video, split_video_args)
 

scenedetect/_cli/commands.py

@@ -217,16 +217,16 @@ def split_video(
     output: str,
     show_output: bool,
     ffmpeg_args: str,
-    expand_to_video: bool,
+    expand: bool,
 ):
     """Handles the `split-video` command."""
     del cuts  # split-video only uses scenes.
     assert context.video_stream is not None
 
-    if expand_to_video and scenes:
+    if expand and scenes:
         video_duration = context.video_stream.duration
         if video_duration is None:
-            logger.warning("Cannot expand-to-video: video duration is unavailable for this stream.")
+            logger.warning("Cannot --expand: video duration is unavailable for this stream.")
         else:
             scenes = expand_scenes_to_bounds(
                 scenes,

scenedetect/_cli/config.py

@@ -468,7 +468,7 @@ class FcpFormat(Enum):
     "split-video": {
         "args": _DEFAULT_FFMPEG_ARGS,
         "copy": False,
-        "expand-to-video": False,
+        "expand": False,
         "filename": "$VIDEO_NAME-Scene-$SCENE_NUMBER",
         "high-quality": False,
         "mkvmerge": False,