# Dubbing and Voice Changer (/en/realtime-media/marketplace/build/add-audio-effects/dubbing-voice-changer/android)

> For AI agents: see the complete documentation index at [llms.txt](/llms.txt).

Dubbing AI Voice Changer extension enables you to change the audio timbre.

This page shows you how to integrate the Dubbing AI Voice Changer extension in your app.

## Understand the tech [#understand-the-tech]

      
    Using the [setExtensionProperty](https://api-ref.agora.io/en/video-sdk/android/4.x/API/class_irtcengine.html#api_irtcengine_setextensionproperty) method provided in Agora SDK v4.x and passing in the specified `key` and `value` parameters, you can quickly integrate real-time AI voice conversion ability into your app.

    The `key` parameter you specify in the `setExtensionProperty` method corresponds to the name of the API, and the `value` parameter wraps some or all of the parameters of the API in JSON format. By passing in the specified `key` and `value` parameters, you can call the corresponding API to realize the functions related to real-time AI sound conversion.

    
  
      
  
## Prerequisites [#prerequisites]

Ensure that your development environment meets the following requirements:

      
    * Android Studio 4.1 or later.
    * A physical device (not an emulator) running Android 5.0 or later.

    
  
      
  
* Dubbing AI Voice Changer is used with Agora Voice SDK v4.x.

  Refer to the [SDK quickstart](/en/realtime-media/voice/quickstart) to integrate Voice SDK v4.x and implement basic voice calling.

## Integrate the extension [#integrate-the-extension]

This section shows you how to integrate the Dubbing AI Voice Changer extension, and call the core API to implement the voice changing function.

      
    1. **Integrate the Dubbing AI Voice Changer extension**

       To integrate the extension in your project:

       1. Enter the [Extensions Marketplace](https://console.agora.io/v2/extensions-marketplace) and download the **Dubbing AI Voice Changer** extension package. After unzipping, save all `.aar` files to the project folder `/app/libs`.
       2. Get the following resource files and save them in the same directory of the project folder. For example, a new `vc_model` directory:
          * License file and tone files: Contact Agora to obtain these files. The suffix of the tone file is `.dat`, and the tone file is issued according to the license.
          * Model file: Download the required resources.
            ![Resource Files](https://assets-docs.agora.io/images/extensions-marketplace/resource-files.png)
       3. Open the `app/build.gradle` file and add the following lines under `dependencies`:

          ```java
          implementation fileTree(dir: "libs", include: ["*.jar", "*.aar"])
          ```

    2. **Enable the plugin**

       After creating and initializing `RtcEngine`, call `enableExtension` to enable the plug-in, before you call other APIs such as `enableVideo` and `joinChannel`.

       ```kotlin
       // Declare parameters
       private val EXTENSION_NAME = "dubbing_vc"
       private val EXTENSION_VENDOR_NAME = "Dubbing"
       private val EXTENSION_AUDIO_FILTER = "DubbingVC"

       private val changeSpeaker_ = "changeSpeaker"
       private val startRealTimeTranscribe_ = "startRealTimeTranscribe"
       private val stopRealTimeTranscribe_ = "stopRealTimeTranscribe"
       private val getSpeakersInfo_ = "getSpeakersInfo"

       val config = RtcEngineConfig()
       config.mContext = baseContext
       config.mAppId = appId
       config.mEventHandler = mRtcEventHandler
       // Load plugin
       config.addExtension(EXTENSION_NAME)
       config.mExtensionObserver = extensionObserver
       // Create and initialize RtcEngine
       mRtcEngine = RtcEngine.create(config)
       mRtcEngine.enableAudio()
       // Enable plugin
       mRtcEngine.enableExtension(EXTENSION_VENDOR_NAME, EXTENSION_AUDIO_FILTER, enable)
       ```

    3. **Set the resource file path**

       When you download and integrate the plug-in, the license, sound, and model files are saved to the specified directory. In this step, you specify the path where these resource files are located.

       ```kotlin
       val modelPath: String = "${context.filesDir}${File.separator}vc_model"
       ```

    4. **Get the tone list**

       After receiving the `onExtensionStarted` callback from Agora SDK, call `getExtensionProperty` passing in the `getSpeakersInfo` key to get the timbre list:

       ```kotlin
       val speakerList = mRtcEngine.getExtensionProperty(
           EXTENSION_VENDOR_NAME,
           EXTENSION_AUDIO_FILTER,
           getSpeakersInfo_
       )
       // Convert JSON to array
       val arr = JSONArray(speakerList)
       ```

       The timbre list is returned as JSON data that you parse yourself.

    5. **Start changing**

       Call `setExtensionProperty` and pass in the corresponding `key` and `value`:

       ```kotlin
       mRtcEngine.setExtensionProperty(
           EXTENSION_VENDOR_NAME,
           EXTENSION_AUDIO_FILTER,
           startRealTimeTranscribe_,
           "true"
       )
       ```

    6. **Select timbre**

       Pass in the timbre ID from the obtained timbre list to set the corresponding timbre:

       ```kotlin
       mRtcEngine.setExtensionProperty(
           EXTENSION_VENDOR_NAME,
           EXTENSION_AUDIO_FILTER,
           changeSpeaker_,
           id
       )
       ```

    7. **Stop changing**

       Call the API to stop the voice changer:

       ```kotlin
       mRtcEngine.setExtensionProperty(
           EXTENSION_VENDOR_NAME,
           EXTENSION_AUDIO_FILTER,
           stopRealTimeTranscribe_,
           "true"
       )
       ```

    8. **Release resources**

       Close the plug-in and release the resources used by the plug-in:

       ```kotlin
       mRtcEngine.enableExtension(EXTENSION_VENDOR_NAME, EXTENSION_AUDIO_FILTER, false)
       ```

    
  
      
  
## Reference [#reference]

This section contains content that completes the information on this page, or points you to documentation that explains other aspects to this product.

      
    ### Sample project [#sample-project]

    The Dubbing AI Voice Changer extension provides a [GitHub sample project](https://github.com/Dubbing-AI-Voice-Changer/DubbingAgoraDemo/tree/main/Android) for testing. To clone and run the project:

    1. Clone the repository

       ```sh
       git clone https://github.com/Dubbing-AI-Voice-Changer/DubbingAgoraDemo.git
       ```

    2. Refer to the `README.md` file in the repository to run the demo.

    ### API reference [#api-reference]

    * [addExtension](https://api-ref.agora.io/en/video-sdk/android/4.x/API/api_irtcengine_addextension.html) in the `RtcEngineConfig` class
    * [enableExtension](https://api-ref.agora.io/en/video-sdk/android/4.x/API/class_irtcengine.html#api_irtcengine_enableextension) in the `RtcEngine` class
    * [setExtensionProperty](https://api-ref.agora.io/en/video-sdk/android/4.x/API/class_irtcengine.html#api_irtcengine_setextensionproperty) in the `RtcEngine` class