vodesfunc.rescale_ext.ignoremask

def border_clipping_mask(
    clip: vs.VideoNode,
    scaling_args: ScalingArgs,
    kernel: Kernel,
    border_handling: BorderHandling,
    dark_thr: float | None = None,
    bright_thr: float | None = 1.0,
) -> vs.VideoNode:
    size_args = dict(
        width=scaling_args.width if scaling_args.mode == "w" else clip.width,
        height=scaling_args.height if scaling_args.mode == "h" else clip.height,
    )

    blank = kernel.rescale(
        clip.std.BlankClip(length=1, color=0.5, keep=True, **size_args),
        clip.width,
        clip.height,
        border_handling=int(border_handling),
        **scaling_args.kwargs(),
    )

    return norm_expr(
        [clip, blank],
        "y 0.5 - dup 0 = not swap {bright_expr} {dark_expr} ? 0 ?",
        bright_expr="0" if bright_thr is None else f"x {bright_thr} >= 255 0 ?",
        dark_expr="0" if dark_thr is None else f"x {dark_thr} <= 255 0 ?",
        format=vs.GRAY8,
    )