import { KoalaModel, KoalaOptions } from './types';
declare class Koala {
    private _module?;
    private readonly _pv_koala_process;
    private readonly _pv_koala_reset;
    private readonly _pv_koala_delete;
    private readonly _delaySample;
    private readonly _frameLength;
    private readonly _sampleRate;
    private readonly _version;
    private readonly _processMutex;
    private readonly _objectAddress;
    private readonly _inputBufferAddress;
    private readonly _outputBufferAddress;
    private readonly _messageStackAddressAddressAddress;
    private readonly _messageStackDepthAddress;
    private static _wasmSimd;
    private static _wasmSimdLib;
    private static _wasmPThread;
    private static _wasmPThreadLib;
    private static _sdk;
    private static _koalaMutex;
    private readonly _processCallback;
    private readonly _processErrorCallback?;
    private constructor();
    /**
     * Delay in samples. If the input and output of consecutive calls to `.process()` are viewed as two contiguous
     * streams of audio data, this delay specifies the time shift between the input and output stream.
     */
    get delaySample(): number;
    /**
     * Get Koala engine version.
     */
    get version(): string;
    /**
     * Get frame length.
     */
    get frameLength(): number;
    /**
     * Get sample rate.
     */
    get sampleRate(): number;
    /**
     * Set base64 wasm file with SIMD feature.
     * @param wasmSimd Base64'd wasm file to use to initialize wasm.
     */
    static setWasmSimd(wasmSimd: string): void;
    /**
     * Set base64 SIMD wasm file in text format.
     * @param wasmSimdLib Base64'd wasm file in text format.
     */
    static setWasmSimdLib(wasmSimdLib: string): void;
    /**
     * Set base64 wasm file with SIMD and pthread feature.
     * @param wasmPThread Base64'd wasm file to use to initialize wasm.
     */
    static setWasmPThread(wasmPThread: string): void;
    /**
     * Set base64 SIMD and thread wasm file in text format.
     * @param wasmPThreadLib Base64'd wasm file in text format.
     */
    static setWasmPThreadLib(wasmPThreadLib: string): void;
    static setSdk(sdk: string): void;
    /**
     * Creates an instance of the Picovoice Koala Noise Suppression Engine.
     * Behind the scenes, it requires the WebAssembly code to load and initialize before
     * it can create an instance.
     *
     * @param accessKey AccessKey obtained from Picovoice Console (https://console.picovoice.ai/)
     * @param processCallback User-defined callback to run after receiving enhanced pcm result.
     * The output is not directly the enhanced version of the input PCM, but corresponds to samples that were given in
     * previous calls to `.process()`. The delay in samples between the start time of the input frame and the start
     * time of the output frame can be attained from `.delaySample`.
     * @param model Koala model options.
     * @param model.base64 The model in base64 string to initialize Koala.
     * @param model.publicPath The model path relative to the public directory.
     * @param model.customWritePath Custom path to save the model in storage.
     * Set to a different name to use multiple models across `koala` instances.
     * @param model.forceWrite Flag to overwrite the model in storage even if it exists.
     * @param model.version Version of the model file. Increment to update the model file in storage.
     * @param options Optional configuration arguments.
     * @param options.device String representation of the device (e.g., CPU or GPU) to use. If set to `best`, the most
     * suitable device is selected automatically. If set to `gpu`, the engine uses the first available GPU device. To select a specific
     * GPU device, set this argument to `gpu:${GPU_INDEX}`, where `${GPU_INDEX}` is the index of the target GPU. If set to
     * `cpu`, the engine will run on the CPU with the default number of threads. To specify the number of threads, set this
     * argument to `cpu:${NUM_THREADS}`, where `${NUM_THREADS}` is the desired number of threads.
     * @param options.processErrorCallback User-defined callback invoked if any error happens
     * while processing the audio stream. Its only input argument is the error message.
     *
     * @returns An instance of the Koala engine.
     */
    static create(accessKey: string, processCallback: (enhancedPcm: Int16Array) => void, model: KoalaModel, options?: KoalaOptions): Promise<Koala>;
    static _init(accessKey: string, processCallback: (enhancedPcm: Int16Array) => void, modelPath: string, options?: KoalaOptions): Promise<Koala>;
    /**
     * Processes a frame of audio. The required sample rate can be retrieved from '.sampleRate' and the length
     * of frame (number of audio samples per frame) can be retrieved from '.frameLength' The audio needs to be
     * 16-bit linearly-encoded. Furthermore, the engine operates on single-channel audio. Consecutive calls to
     * `.process()` must provide consecutive frames of audio from the same source, unless `.reset()` has been
     * called in between.
     *
     * @param pcm A frame of audio with properties described above.
     */
    process(pcm: Int16Array): Promise<void>;
    /**
     * Resets Koala into a state as if it had just been newly created.
     * Call this function in between calls to `process` that do not provide consecutive frames of audio.
     */
    reset(): Promise<void>;
    /**
     * Releases resources acquired by WebAssembly module.
     */
    release(): Promise<void>;
    onmessage(e: MessageEvent): Promise<void>;
    /**
     * Lists all available devices that Koala can use for inference.
     * Each entry in the list can be the used as the `device` argument for the `.create` method.
     *
     * @returns List of all available devices that Koala can use for inference.
     */
    static listAvailableDevices(): Promise<string[]>;
    private static initWasm;
    private static getMessageStack;
    private static wrapAsyncFunction;
}
export default Koala;
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