No .cube LUT files are bundled with video-fx.

To use a user-supplied LUT, pass the file path via config.extra:

    import video_fx
    video_fx.apply_effect(
        video="input.mp4",
        effect="bleach_bypass",
        output="output.mp4",
        extra={"lut_path": "/path/to/your.cube"},
    )

The lut_grade engine supports standard .cube format (Adobe/DaVinci Resolve).
If the specified file is not found at runtime, the engine falls back to the
built-in numpy approximation for that preset and emits a UserWarning.

Free LUT collections:
  - https://luts.iwltbap.com/
  - https://www.freepresets.com/product/free-luts/
  - https://groundcontrol.film/free-luts

The .cube file must follow the standard layout:
  LUT_SIZE <N>
  <R G B> (floating point, one line per entry, blue-fastest order)
