/**
 * Motion-graphics overlays for the assemble layer (the After-Effects-shaped gap):
 * composite a graphic onto footage, burn an animated alert, or a lower-third title
 * — all time-gated with fades. These are PURE FFmpeg arg-builders (the tested
 * surface; ffmpeg is never spawned here), mirroring stitch.ts. They pair with
 * gen-image: generate a "SYSTEM COMPROMISED" / dashboard graphic, then overlay it.
 *
 * Conventions: `-y` is auto-prepended by runFfmpeg, so it is NOT included here.
 * Time gating uses `enable='between(t,start,end)'`; fades use the `fade` filter on
 * the overlay's alpha, so the composite eases in/out rather than popping.
 *
 * VALIDATION STATUS: {@link buildOverlayArgs} (graphic composite) is real-render
 * validated — pair it with gen-image to overlay a generated "SYSTEM COMPROMISED" /
 * dashboard graphic with no font dependency (the recommended path). The two text
 * builders ({@link buildAlertTextArgs}, {@link buildLowerThirdArgs}) use the
 * `drawtext` filter, which requires an ffmpeg built with libfreetype; their arg
 * shapes are unit-tested but NOT render-validated on every host. On a drawtext-less
 * ffmpeg, render the text to a PNG (gen-image / a title-card) and composite it via
 * buildOverlayArgs instead.
 */
export type OverlayPosition = 'top-left' | 'top-right' | 'bottom-left' | 'bottom-right' | 'center' | 'bottom-center' | 'top-center' | 'full';
export declare const OVERLAY_POSITION_IDS: OverlayPosition[];
export interface BuildOverlayOptions {
    position?: OverlayPosition;
    /** Visible window in seconds. Defaults to the whole clip (no `enable` gate). */
    startSec?: number;
    endSec?: number;
    fadeInSec?: number;
    fadeOutSec?: number;
    /** 0..1 overall opacity. Default 1. */
    opacity?: number;
    /** Inset from the frame edge in px (ignored for `center`/`full`). Default 48. */
    margin?: number;
    /** H.264 CRF. Default 18 (overlays want to preserve text edges). */
    crf?: number;
}
/**
 * Composite a graphic (PNG/MP4-with-alpha) onto a base video (PURE). Fades the
 * overlay's alpha in/out and gates it to [startSec, endSec] when given. `full`
 * scales the graphic to the frame; other positions overlay at native size.
 */
export declare function buildOverlayArgs(baseVideo: string, graphic: string, outputPath: string, opts?: BuildOverlayOptions): string[];
export interface BuildAlertTextOptions {
    startSec?: number;
    endSec?: number;
    /** Pulse frequency in Hz (the flash rate). Default 2. */
    pulseHz?: number;
    /** Text color. Default red. */
    color?: string;
    fontSize?: number;
    /** Draw a flashing border box. Default true. */
    border?: boolean;
    crf?: number;
}
/**
 * Burn an animated alert (e.g. "SYSTEM COMPROMISED") onto a base video WITHOUT a
 * pre-rendered graphic (PURE). The text alpha pulses via a sine expression and an
 * optional border box flashes in sync, gated to [startSec, endSec]. This is the
 * templated motion-graphic the reference advert uses for its breach moment.
 */
export declare function buildAlertTextArgs(baseVideo: string, text: string, outputPath: string, opts?: BuildAlertTextOptions): string[];
export interface BuildLowerThirdOptions {
    startSec?: number;
    endSec?: number;
    fadeInSec?: number;
    fadeOutSec?: number;
    fontSize?: number;
    color?: string;
    /** Background box color@opacity, e.g. `black@0.55`. Default `black@0.55`. */
    boxColor?: string;
    /** Inset from the bottom-left in px. Default 64. */
    margin?: number;
    crf?: number;
}
/**
 * Burn a lower-third title (text on a translucent box, bottom-left) onto a base
 * video (PURE), gated to [startSec, endSec] with optional fades. The standard
 * name/role caption the reference uses to introduce characters.
 */
export declare function buildLowerThirdArgs(baseVideo: string, text: string, outputPath: string, opts?: BuildLowerThirdOptions): string[];
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