import MediaStreamBrokerObserver from '../mediastreambrokerobserver/MediaStreamBrokerObserver';
/**
 * Media controllers acquire media streams from the [[MediaStreamBroker]], which
 * fulfills the requests either through direct getUserMedia requests or a
 * higher-level intermediary such as a [[DeviceController]].
 */
export default interface MediaStreamBroker {
    /**
     * Called when the session needs to attach an audio input to the peer
     * connection.
     */
    acquireAudioInputStream(): Promise<MediaStream>;
    /**
     * Called when the session needs to attach a video input to the peer
     * connection.
     */
    acquireVideoInputStream(): Promise<MediaStream>;
    /**
     * Called when the session needs to acquire a display input device for screen sharing.
     */
    acquireDisplayInputStream(streamConstraints: MediaStreamConstraints): Promise<MediaStream>;
    /**
     * Mute the current active local audio input stream.
     */
    muteLocalAudioInputStream(): void;
    /**
     * Unmute the current active local audio input
     */
    unmuteLocalAudioInputStream(): void;
    /**
     * Add a media stream broker observer to receive events when input/output streams change
     * @param observer The observer to be added
     */
    addMediaStreamBrokerObserver(observer: MediaStreamBrokerObserver): void;
    /**
     * Remove a media stream broker observer to stop receiving events when input/output streams change
     * @param observer The observer to be removed
     */
    removeMediaStreamBrokerObserver(observer: MediaStreamBrokerObserver): void;
}