Class SceneManager

scenedetect/scene_manager.py:190–703

The SceneManager facilitates detection of scenes (:meth:`detect_scenes`) on a video (:class:`VideoStream `) using a detector (:meth:`add_detector`). Video decoding is done in parallel in a background thread.

class SceneManager:
    """The SceneManager facilitates detection of scenes (:meth:`detect_scenes`) on a video
    (:class:`VideoStream <scenedetect.video_stream.VideoStream>`) using a detector
    (:meth:`add_detector`). Video decoding is done in parallel in a background thread.
    """

    def __init__(
        self,
        stats_manager: StatsManager | None = None,
    ):
        """
        Arguments:
            stats_manager: :class:`StatsManager` to bind to this `SceneManager`. Can be
                accessed via the `stats_manager` property of the resulting object to save to disk.
        """
        self._cutting_list: list[FrameTimecode] = []
        self._detector_list: list[SceneDetector] = []
        # TODO(v1.0): This class should own a StatsManager instead of taking an optional one.
        # Expose a new `stats_manager` @property from the SceneManager, and either change the
        # `stats_manager` argument to to `store_stats: bool=False`, or lazy-init one.

        # TODO(v1.0): This class should own a VideoStream as well, instead of passing one
        # to the detect_scenes method. If concatenation is required, it can be implemented as
        # a generic VideoStream wrapper.
        self._stats_manager: StatsManager | None = stats_manager

        # Position of video that was first passed to detect_scenes.
        self._start_pos: FrameTimecode | None = None
        # Position of video on the last frame processed by detect_scenes.
        self._last_pos: FrameTimecode | None = None
        # Size of the decoded frames.
        self._frame_size: tuple[int, int] | None = None
        self._frame_size_errors: int = 0
        self._base_timecode: FrameTimecode | None = None
        self._downscale: int = 1
        self._auto_downscale: bool = True
        # Interpolation method to use when downscaling. Defaults to linear interpolation
        # as a good balance between quality and performance.
        self._interpolation: Interpolation = Interpolation.LINEAR
        # Set by decode thread when an exception occurs.
        self._exception_info = None
        self._stop = threading.Event()

        self._frame_buffer: list[tuple[FrameTimecode, np.ndarray]] = []
        self._frame_buffer_size = 0
        self._crop = None

    @property
    def interpolation(self) -> Interpolation:
        """Interpolation method to use when downscaling frames. Must be one of cv2.INTER_*."""
        return self._interpolation

    @interpolation.setter
    def interpolation(self, value: Interpolation):
        self._interpolation = value

    @property
    def stats_manager(self) -> StatsManager | None: