/**
 * [[VideoFrameBuffer]] is an interface that can be used as input or output with {@link VideoFrameProcessor}.
 * It must implement the method to return buffer as `CanvasImageSource` but the internal handle to the video frame buffer can be flexible.
 */
export default interface VideoFrameBuffer {
    /**
     * The frame rate of the source in the [[VideoFrameBuffer]].
     */
    framerate: number;
    /**
     *  The width in pixels of the source in the [[VideoFrameBuffer]].
     */
    width: number;
    /**
     * The height in pixels of the source in the [[VideoFrameBuffer]].
     */
    height: number;
    /**
     * Explicitly destroys the source and intermediate buffers in [[VideoFrameBuffer]].
     * After `destroy` is called, this [[VideoFrameBuffer]] must be discarded.
     * `destroy` is typically required to be called, when `MediaStream`, `HTMLVideoElement` and `ImageData` are passed in as initialization data.
     */
    destroy(): void;
    /**
     * Returns the buffer as `CanvasImageSource` which can be drawn on HTMLCanvasElement directly.
     * If `destroy` is already called, `asCanvasImageSource` should reject.
     */
    asCanvasImageSource(): Promise<CanvasImageSource>;
    /**
     * Returns `HTMLCanvasElement` or `OffscreenCanvas` if the internal source can be transformed into one. Optional method.
     * Returns `null` if the buffer is destroyed.
     */
    asCanvasElement?(): HTMLCanvasElement | OffscreenCanvas | null;
    /**
     * Returns [[Transferable]] if the internal source can be transformed into one. Optional method.
     * If `destroy` is already called, `asTransferable` should reject.
     */
    asTransferable?(): Promise<Transferable>;
}