[save-images] Add multithreaded version of save-images

scenedetect.cfg

@@ -220,22 +220,25 @@
 # Image quality (jpeg/webp). Default is 95 for jpeg, 100 for webp
 #quality = 95
 
-# Compression amount for png images (0 to 9). Does not affect quality.
+# Compression amount for png images (0 to 9). Only affects size, not quality.
 #compression = 3
 
-# Number of frames to skip at beginning/end of scene.
+# Number of frames to ignore around each scene cut when selecting frames.
 #frame-margin = 1
 
-# Factor to resize images by (0.5 = half, 1.0 = same, 2.0 = double).
+# Resize by scale factor (0.5 = half, 1.0 = same, 2.0 = double).
 #scale = 1.0
 
-# Override image height and/or width. Mutually exclusive with scale.
+# Resize to specified height, width, or both. Mutually exclusive with scale.
 #height = 0
 #width = 0
 
-# Method to use for image scaling (nearest, linear, cubic, area, lanczos4).
+# Method to use for scaling (nearest, linear, cubic, area, lanczos4).
 #scale-method = linear
 
+# Use separate threads for encoding and disk IO. Can improve performance.
+#threading = yes
+
 
 [export-html]
 # Filename format of created HTML file. Can use $VIDEO_NAME in the name.

scenedetect/__init__.py

@@ -15,8 +15,8 @@
 :class:`SceneManager <scenedetect.scene_manager.SceneManager>`.
 """
 
+import typing as ty
 from logging import getLogger
-from typing import List, Optional, Tuple, Union
 
 # OpenCV is a required package, but we don't have it as an explicit dependency since we
 # need to support both opencv-python and opencv-python-headless. Include some additional
@@ -30,6 +30,7 @@
     ) from ex
 
 # Commonly used classes/functions exported under the `scenedetect` namespace for brevity.
+# Note that order of importants is important!
 from scenedetect.platform import init_logger  # noqa: I001
 from scenedetect.frame_timecode import FrameTimecode
 from scenedetect.video_stream import VideoStream, VideoOpenFailure
@@ -50,7 +51,7 @@
     VideoCaptureAdapter,
 )
 from scenedetect.stats_manager import StatsManager, StatsFileCorrupt
-from scenedetect.scene_manager import SceneManager, save_images
+from scenedetect.scene_manager import SceneManager, save_images, SceneList, CutList, Interpolation
 from scenedetect.video_manager import VideoManager  # [DEPRECATED] DO NOT USE.
 
 # Used for module identification and when printing version & about info
@@ -63,7 +64,7 @@
 
 def open_video(
     path: str,
-    framerate: Optional[float] = None,
+    framerate: ty.Optional[float] = None,
     backend: str = "opencv",
     **kwargs,
 ) -> VideoStream:
@@ -117,12 +118,12 @@ def open_video(
 def detect(
     video_path: str,
     detector: SceneDetector,
-    stats_file_path: Optional[str] = None,
+    stats_file_path: ty.Optional[str] = None,
     show_progress: bool = False,
-    start_time: Optional[Union[str, float, int]] = None,
-    end_time: Optional[Union[str, float, int]] = None,
+    start_time: ty.Optional[ty.Union[str, float, int]] = None,
+    end_time: ty.Optional[ty.Union[str, float, int]] = None,
     start_in_scene: bool = False,
-) -> List[Tuple[FrameTimecode, FrameTimecode]]:
+) -> SceneList:
     """Perform scene detection on a given video `path` using the specified `detector`.
 
     Arguments:
@@ -143,7 +144,7 @@ def detect(
             will always be included until the first fade-out event is detected.
 
     Returns:
-        List of scenes (pairs of :class:`FrameTimecode` objects).
+        List of scenes as pairs of (start, end) :class:`FrameTimecode` objects.
 
     Raises:
         :class:`VideoOpenFailure`: `video_path` could not be opened.

scenedetect/_cli/__init__.py

@@ -1493,7 +1493,8 @@ def save_images_command(
         "num_images": ctx.config.get_value("save-images", "num-images", num_images),
         "output_dir": output,
         "scale": scale,
-        "show_progress": ctx.quiet_mode,
+        "show_progress": not ctx.quiet_mode,
+        "threading": ctx.config.get_value("save-images", "threading"),
         "width": width,
     }
     ctx.add_command(cli_commands.save_images, save_images_args)

scenedetect/_cli/commands.py

@@ -29,9 +29,7 @@
     write_scene_list,
     write_scene_list_html,
 )
-from scenedetect.scene_manager import (
-    save_images as save_images_impl,
-)
+from scenedetect.scene_manager import save_images as save_images_impl
 from scenedetect.video_splitter import split_video_ffmpeg, split_video_mkvmerge
 
 logger = logging.getLogger("pyscenedetect")
@@ -179,6 +177,7 @@ def save_images(
     height: int,
     width: int,
     interpolation: Interpolation,
+    threading: bool,
 ):
     """Handles the `save-images` command."""
     del cuts  # save-images only uses scenes.
@@ -197,6 +196,7 @@ def save_images(
         height=height,
         width=width,
         interpolation=interpolation,
+        threading=threading,
     )
     # Save the result for use by `export-html` if required.
     context.save_images_result = (images, output_dir)

scenedetect/_cli/config.py

@@ -361,6 +361,7 @@ def format(self, timecode: FrameTimecode) -> str:
         "quality": RangeValue(_PLACEHOLDER, min_val=0, max_val=100),
         "scale": 1.0,
         "scale-method": Interpolation.LINEAR,
+        "threading": True,
         "width": 0,
     },
     "save-qp": {