Configure audio encoding

Audio quality requirements vary with application use-case. For example. in professional use-cases such as radio stations and singing competitions users are particularly sensitive to audio quality. In such cases, support for dual-channel and high-quality sound is required. High-quality sound means setting a high sampling rate and a high bitrate to achieve realistic audio. Video SDK enables you to configure audio encoding properties to meet such requirements.

This article shows you how to use Video SDK to configure appropriate audio encoding properties and application scenarios in your app.

Video SDK uses default encoding parameters and a default audio scenario that are suitable for most common applications. If the default settings do not meet your needs, refer to the examples in the implementation section to set appropriate audio encoding properties and an application scenario.

Ensure that you have implemented the SDK quickstart in your project.

This section shows you how to set audio encoding properties and application scenarios for common applications. You use the following APIs to configure audio encoding:

API	Description
sharedEngineWithConfig(config.audioScenario)	While creating an AgoraRtcEngineKit instance, set up the audio application scenario. The default value is AgoraAudioScenarioHighDefault.
setAudioProfile(profile)	You can set audio encoding properties before or after joining a channel.
setAudioScenario	You can set an application scenario before or after joining a channel.

Refer to the following examples to choose the most appropriate settings for your application.

This use-case requires ensuring call quality and smooth transmission. Add the following code to your project:

// Create the AgoraRtcEngineKit instance with a specific audio application scenario

var scenario:AgoraAudioScenario = .default

config.audioScenario = audioScenario

agoraKit = AgoraRtcEngineKit.sharedEngine(with: config, delegate: self)

// Define the audio encoding settings

var profile:AgoraAudioProfile = .default

agoraKit.setAudioProfile(audioProfile)

This use-case requires the transmission of clear human voice with minimal background noise and at a low bitrate. Agora recommends the following settings:

// Create the AgoraRtcEngineKit instance with a specific audio application scenario

var scenario:AgoraAudioScenario = .chatRoom

config.audioScenario = audioScenario

agoraKit = AgoraRtcEngineKit.sharedEngine(with: config, delegate: self)

// Define the audio encoding settings

var profile:AgoraAudioProfile = .speechStandard

agoraKit.setAudioProfile(audioProfile)

This use-case requires good sound expression, and no volume or sound quality change when switching microphones. Agora recommends the following settings:

// Create the AgoraRtcEngineKit instance with a specific audio application scenario

var scenario:AgoraAudioScenario = .chatRoom

config.audioScenario = audioScenario

agoraKit = AgoraRtcEngineKit.sharedEngine(with: config, delegate: self)

// Define the audio encoding settings

var profile:AgoraAudioProfile = .musicStandard

agoraKit.setAudioProfile(audioProfile)

KTV generally requires high sound quality and good expressiveness for music and singing. Use the following code in your project:

// Create the AgoraRtcEngineKit instance with a specific audio application scenario

var scenario:AgoraAudioScenario = .gameStreaming

config.audioScenario = audioScenario

agoraKit = AgoraRtcEngineKit.sharedEngine(with: config, delegate: self)

// Define the audio encoding settings

var profile:AgoraAudioProfile = .musicHighQuality

agoraKit.setAudioProfile(audioProfile)

Voice radio generally uses professional audio equipment. It requires high sound quality and stereo. Use the following code in your project:

// Create the AgoraRtcEngineKit instance with a specific audio application scenario

var scenario:AgoraAudioScenario = .gameStreaming

config.audioScenario = audioScenario

agoraKit = AgoraRtcEngineKit.sharedEngine(with: config, delegate: self)

// Set the required audio encoding properties

var profile:AgoraAudioProfile = .musicHighQualityStereo

agoraKit.setAudioProfile(audioProfile)

This use-case requires high sound quality, and support for the transmission of speaker-played sound effects. Agora recommends the following settings:

// Create the AgoraRtcEngineKit instance with a specific audio application scenario

var scenario:AgoraAudioScenario = .gameStreaming

config.audioScenario = audioScenario

agoraKit = AgoraRtcEngineKit.sharedEngine(with: config, delegate: self)

// Define the audio encoding settings

var profile:AgoraAudioProfile = .musicStandardStereo

agoraKit.setAudioProfile(audioProfile)

This use-case requires high sound quality with rich sound effects, and no volume or sound quality change when switching microphones. Agora recommends the following settings:

// Create the AgoraRtcEngineKit instance with a specific audio application scenario

var audioScenario:AgoraAudioScenario = .chatRoom

config.audioScenario = audioScenario

agoraKit = AgoraRtcEngineKit.sharedEngine(with: config, delegate: self)

// Define the audio encoding settings

var profile:AgoraAudioProfile = .musicStandardStereo

agoraKit.setAudioProfile(audioProfile)

Information

Due to iOS system limitations, some audio routes cannot be recognized in call volume mode. Therefore, if you need to use an external sound card, it is recommended to set the audio application scene to the high-quality scenario AudioScenarioGameStreaming(3). In this scenario, the SDK switches to media volume to address the issue.

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

For more audio settings, see Achieve high audio quality.

• What is the difference between the in-call volume and the media volume?

Agora offers the following open-source sample project for setting audio encoding properties and application scenario functions for your reference.

• JoinChannelAudio

• sharedEngine(with: config, delegate)
• AgoraRtcEngineConfig
• setAudioProfile
• setAudioScenario