Custom Audio Source

The default Agora audio module interacts seamlessly with the devices your app runs on. The SDK enables you to add specialized audio features to your app using a custom audio source.

Understand the tech

By default, SDK integrates the default audio modules on the device your app runs on for real-time communication. However, there are scenarios where you may want to integrate a custom audio capturer. For example:

• Your app has its own audio module.
• You need to process the captured audio with a pre-processing library.
• You need flexible device resource allocation to avoid conflicts with other services.

To manage the capture and processing of audio frames when using a custom audio source, use methods from outside the Agora SDK.

API call sequence

The following figure shows the call sequence you need to implement in your app for custom audio source:

Audio data transfer

The following figure shows how the audio data is transferred when you customize the audio source:

• You need to implement the capture module yourself using methods from outside the SDK.
• Call pushExternalAudioFrame to send the captured audio frames to the SDK.

Prerequisites

Before proceeding, ensure that you have implemented the basic real-time communication functions in your project. For details, see Start a Call or Start Interactive Live Streaming.

Implementation

To implement a custom audio source in your project, refer to the following steps.

1. Before calling joinChannel, call setExternalAudioSource to specify the custom audio source.

    // Specifies the custom audio source
    engine.setExternalAudioSource(true, DEFAULT_SAMPLE_RATE, DEFAULT_CHANNEL_COUNT, 1, true, true);
    // The local user joins the channel
    ChannelMediaOptions option = new ChannelMediaOptions();
    option.autoSubscribeAudio = true;
    option.autoSubscribeVideo = true;
    int res = engine.joinChannel(accessToken, channelId, 0, option);

2. Implement audio capture and processing yourself using methods from outside the SDK.

3. Call pushExternalAudioFrame to send the audio frames to the SDK for later use.

    engine.pushExternalAudioFrame(ByteBuffer.wrap(buffer), 0, 0);

Reference

This section includes in depth information about the methods you used in this page, and links to related pages.

Sample project

Agora provides an open-source demo project on GitHub. You can view the source code on Github or download the project to try it out.

API reference

• setExternalAudioSource [1/2]
• setExternalAudioSource [2/2]
• pushExternalAudioFrame [1/2]
• pushExternalAudioFrame [2/2]