Agora C++ API Reference for All Platforms

Agora provides ensured quality of experience (QoE) for worldwide Internet-based voice and video communications through a virtual global network optimized for real-time web and mobile-to-mobile applications.

• As of v2.3.3, Agora C++ API Reference for All Platforms can be downloaded from Dash, see FAQ for details.
• As of v3.0.0, Agora deprecates the RtcEngineParameters class. IRtcEngine class covers all APIs of the RtcEngineParameters class, use the IRtcEngine class instead.

• The IRtcEngine class is the entry point of the Agora SDK providing API methods for applications to quickly start a voice/video communication or interactive broadcast.
• The IRtcEngineEventHandler class reports runtime events to the applications.
• The IChannel class provides methods that enable real-time communications in a specified channel. By creating multiple IChannel objects, the user can join multiple channels.
• The IChannelEventHandler class provides callbacks that report events and statistics of a specified channel.
• The IAudioDeviceManager class allows for audio device interface testing.
• The IVideoDeviceManager class allows for video device interface testing.

Channel Management

Method	Description
createAgoraRtcEngine	Creates an RtcEngine object and returns the pointer.
initialize	Initializes the Agora SDK service.
release	Releases all IRtcEngine resources.
setChannelProfile	Sets the channel profile in a live broadcast.
setClientRole	Sets the role of the user in a live broadcast.
joinChannel	Allows a user to join a channel.
switchChannel	Switches to a different channel in a live broadcast.
leaveChannel	Allows a user to leave a channel.
renewToken	Renews the Token.
getConnectionState	Gets the current connection state of the SDK.

Channel Events

Event	Description
onConnectionStateChanged	Occurs when the connection state between the SDK and the server changes.
onJoinChannelSuccess	Occurs when a user joins a channel.
onRejoinChannelSuccess	Occurs when a user rejoins the channel.
onLeaveChannel	Occurs when a user leaves the channel.
onClientRoleChanged	Occurs when the user role switches in a live broadcast.
onUserJoined	Occurs when a remote user (Communication)/ host (Live Broadcast) joins the channel.
onUserOffline	Occurs when a remote user (Communication)/ host (Live Broadcast) leaves the channel.
onNetworkTypeChanged	Occurs when the local network type changes.
onConnectionLost	Occurs when the SDK cannot reconnect to Agora's edge server 10 seconds after its connection to the server is interrupted.
onTokenPrivilegeWillExpire	Occurs when the token expires in 30 seconds.
onRequestToken	Occurs when the token expires.

Audio Management

Method	Description
enableAudio	Enables the audio module.
disableAudio	Disables the audio module.
setAudioProfile	Sets the audio parameters and application scenarios.
adjustRecordingSignalVolume	Adjusts the recording volume.
adjustUserPlaybackSignalVolume	Adjusts the playback volume of a specified remote user.
adjustPlaybackSignalVolume	Adjusts the playback volume of all remote users.
enableLocalAudio	Enables/Disables the local audio sampling.
muteLocalAudioStream	Stops/Resumes sending the local audio stream.
muteRemoteAudioStream	Stops/Resumes receiving the audio stream from a specified remote user.
muteAllRemoteAudioStreams	Stops/Resumes receiving all remote users' audio streams.
setDefaultMuteAllRemoteAudioStreams	Stops/Resumes receiving all remote users' audio streams by default.

Video Management

Method	Description
enableVideo	Enables the video module.
disableVideo	Disables the video module.
setVideoEncoderConfiguration	Sets the video encoder configuration.
setupLocalVideo	Initializes the local video view.
setupRemoteVideo	Initializes the video view of a remote user.
setLocalRenderMode	Updates the display mode of the local video view.
setRemoteRenderMode	Updates the display mode of the video view of a remote user.
startPreview	Starts the local video preview before joining the channel.
stopPreview	Stops the local video preview and disables video.
enableLocalVideo	Enables/Disables the local video capture.
muteLocalVideoStream	Stops/Resumes sending the local video stream.
muteRemoteVideoStream	Stops/Resumes receiving the video stream from a specified remote user.
muteAllRemoteVideoStreams	Stops/Resumes receiving all video stream from a specified remote user.
setDefaultMuteAllRemoteVideoStreams	Stops/Resumes receiving all remote users' video streams by default.

Local Media Events

Event	Description
onLocalAudioStateChanged	Occurs when the local audio state changes.
onLocalVideoStateChanged	Occurs when the local video state changes.
onFirstLocalAudioFrame	Occurs when the first local audio frame is sent.
onFirstLocalVideoFrame	Occurs when the first local video frame is rendered.

Remote Media Events

Event	Description
onRemoteAudioStateChanged	Occurs when the remote audio state changes.
onRemoteVideoStateChanged	Occurs when the remote video state changes.
onUserMuteVideo	Occurs when a remote user's video stream playback pauses/resumes.

Statistics Events

After joining a channel, SDK triggers this group of callbacks once every two seconds. We provide an advanced guide for these callbacks. For details, see Report In-call Statistics.

Event	Description
onRtcStats	Reports the statistics of the current call session.
onNetworkQuality	Reports the network quality of each user.
onLocalAudioStats	Reports the statistics of the local audio stream.
onLocalVideoStats	Reports the statistics of the local video stream.
onRemoteAudioStats	Reports the statistics of the audio stream from each remote user/host.
onRemoteVideoStats	Reports the statistics of the video stream from each remote user/host.

Video Pre-process and Post-process

Method	Description
setBeautyEffectOptions	Sets the image enhancement options.

Multiple Channels Management

We provide an advanced guide on the applicable scenarios, implementation and considerations for this group of methods. For details, see Join multiple channels.

API	Description
createChannel	Initializes and gets an IChannel object. To join multiple channels, create multiple IChannel objects.
IChannel	Provides methods that enable real-time communications in a specified channel.
IChannelEventHandler	Provides callbacks that report events and statistics in a specified channel.

Screen Capture

We provide an advanced guide on the applicable scenarios, implementation and considerations for this group of methods. For details, see Share the Screen.

Method	Description
startScreenCaptureByDisplayId	Shares the whole or part of a screen by specifying the display ID (for macOS only).
startScreenCaptureByScreenRect	Shares the whole or part of a screen by specifying the screen rect.
startScreenCaptureByWindowId	Shares the whole or part of a window by specifying the window ID.
setScreenCaptureContentHint	Sets the content hint for screen sharing.
updateScreenCaptureParameters	Updates the screen sharing parameters.
updateScreenCaptureRegion	Updates the screen sharing region.
stopScreenCapture	Stops screen sharing.

Audio File Playback and Mixing

Method	Description
startAudioMixing	Starts playing and mixing the music file.
stopAudioMixing	Stops playing and mixing the music file.
pauseAudioMixing	Pauses playing and mixing the music file.
resumeAudioMixing	Resumes playing and mixing the music file.
adjustAudioMixingVolume	Adjusts the volume during audio mixing.
adjustAudioMixingPlayoutVolume	Adjusts the volume of audio mixing for local playback.
adjustAudioMixingPublishVolume	Adjusts the volume of audio mixing for remote playback.
getAudioMixingPlayoutVolume	Gets the audio mixing volume for local playback.
getAudioMixingPublishVolume	Gets the audio mixing volume for publishing.
getAudioMixingDuration	Gets the duration (ms) of the music file.
getAudioMixingCurrentPosition	Gets the playback position (ms) of the music file.
setAudioMixingPosition	Sets the playback position of the music file.

Event	Description
onAudioMixingStateChanged	Occurs when the state of the local user's audio mixing file changes.
onRemoteAudioMixingBegin	Occurs when a remote user starts audio mixing.
onRemoteAudioMixingEnd	Occurs when a remote user finishes audio mixing.

Audio Effect Playback

Method	Description
getEffectsVolume	Gets the volume of the audio effects.
setEffectsVolume	Sets the volume of the audio effects.
setVolumeOfEffect	Sets the volume of the audio effect.
playEffect	Plays a specified audio effect.
stopEffect	Stops playing a specified audio effect.
stopAllEffects	Stops playing all audio effects.
preloadEffect	Preloads a specified audio effect file into the memory.
unloadEffect	Releases a specified audio effect from the memory.
pauseEffect	Pauses a specified audio effect.
pauseAllEffects	Pauses all audio effects.
resumeEffect	Resumes playing a specified audio effect.
resumeAllEffects	Resumes playing all audio effects.

Event	Description
onAudioEffectFinished	Occurs when the local audio effect playback finishes.

Voice Changer and Reverberation

Method	Description
setLocalVoiceChanger	Sets the local voice changer option.
setLocalVoiceReverbPreset	Sets the preset local voice reverberation effect.
setLocalVoicePitch	Changes the voice pitch of the local speaker.
setLocalVoiceEqualization	Sets the local voice equalization effect.
setLocalVoiceReverb	Sets the local voice reverberation.

Sound Position Indication

Method	Description
enableSoundPositionIndication	Enables/Disables stereo panning for remote users.
setRemoteVoicePosition	Sets the sound position and gain of a remote user.

CDN Publisher

This group of methods apply to Live Broadcast only.

Method	Description
setLiveTranscoding	Sets the video layout and audio for CDN live.
addPublishStreamUrl	Adds a CDN stream address.
removePublishStreamUrl	Removes a CDN stream address.

Event	Description
onRtmpStreamingStateChanged	Occurs when the state of the RTMP streaming changes.
onTranscodingUpdated	Occurs when the publisher's transcoding settings are updated.

Media Stream Relay Across Channels

This group of methods apply to Live Broadcast only.

Method	Description
startChannelMediaRelay	Starts to relay media streams across channels.
updateChannelMediaRelay	Updates the channels for media stream relay.
stopChannelMediaRelay	Stops the media stream relay.

Event	Description
onChannelMediaRelayStateChanged	Occurs when the state of the media stream relay changes.
onChannelMediaRelayEvent	Reports events during the media stream relay.

Audio Volume Indication

Method	Description
enableAudioVolumeIndication	Enables the onAudioVolumeIndication callback at a set time interval to report on which users are speaking and the speakers' volume.

Event	Description
onAudioVolumeIndication	Reports which users are speaking, the speakers' volumes, and whether the local user is speaking.
onActiveSpeaker	Reports which user is the loudest speaker.

Audio Routing Control

Method	Description
setDefaultAudioRouteToSpeakerphone	Sets the default audio playback route (for Android and iOS only).
setEnableSpeakerphone	Enables/Disables the audio playback route to the speakerphone (for Android and iOS only).
isSpeakerphoneEnabled	Checks whether the speakerphone is enabled (for Android and iOS only).

Event	Description
onAudioRouteChanged	Occurs when the local audio route changes (for Android and iOS only).

In-ear Monitoring

Method	Description
setInEarMonitoringVolume	Sets the volume of the in-ear monitor (for Android and iOS only).

Dual Video Stream Mode

Method	Description
enableDualStreamMode	Sets the stream mode to single- (default) or dual-stream mode.
setRemoteVideoStreamType	Sets the remote user’s video stream type received by the local user when the remote user sends dual streams.
setRemoteDefaultVideoStreamType	Sets the default video-stream type for the video received by the local user when the remote user sends dual streams.

Stream Fallback

• We provide an advanced guide on the applicable scenarios, implementation and considerations for this group of methods. For details, see Video Stream Fallback.

Method	Description
setLocalPublishFallbackOption	Sets the fallback option for the published video stream under unreliable network conditions.
setRemoteSubscribeFallbackOption	Sets the fallback option for the remote stream under unreliable network conditions.
setRemoteUserPriority	Prioritizes a remote user's stream.

Event	Description
onLocalPublishFallbackToAudioOnly	Occurs: When the published media stream falls back to an audio-only stream due to poor network conditions. When the published media stream switches back to the video after the network conditions improve.
onRemoteSubscribeFallbackToAudioOnly	Occurs: When the remote media stream falls back to audio-only due to poor network conditions. When the remote media stream switches back to the video after the network conditions improve.

Pre-call Network Test

We provide an advanced guide on the applicable scenarios, implementation and considerations for this group of methods. For details, see Conduct a Last-mile Test.

Method	Description
startEchoTest	Starts an audio call test.
stopEchoTest	Stops the audio call test.
enableLastmileTest	Enables the network connection quality test.
disableLastmileTest	Disables the network connection quality test.
startLastmileProbeTest	Starts the last-mile network probe test.
stopLastmileProbeTest	Stops the last-mile network probe test.

Event	Description
onLastmileQuality	Reports the last mile network quality of the local user before the user joins the channel.
onLastmileProbeResult	Reports the last-mile network probe result.

Custom Video Module

• N/A

External Video Data (Push-mode only)

Method	Description
setExternalVideoSource	Configures the external video source.
pushVideoFrame	Pushes the external video frame.

External Audio Data (Push-mode only)

Method	Description
setExternalAudioSource	Configures the external audio source.
pushAudioFrame	Pushes the external audio frame.

External Audio Sink (Pull-mode only)

This group of methods are for Windows only.

Method	Description
setExternalAudioSink	Sets the external audio sink.
pullAudioFrame	Pulls the external audio frame.

Raw Audio Data

Method	Description
registerAudioFrameObserver	Registers an audio frame observer object.
setRecordingAudioFrameParameters	Sets the audio recording format for the onRecordAudioFrame callback.
setPlaybackAudioFrameParameters	Sets the audio playback format for the onPlaybackAudioFrame callback.
setMixedAudioFrameParameters	Sets the mixed audio format for the onMixedAudioFrame callback.

Event	Description
onRecordAudioFrame	Occurs when the recorded audio frame is received.
onPlaybackAudioFrame	Occurs when the audio playback frame is received.
onPlaybackAudioFrameBeforeMixing	Occurs when the audio playback frame of a specified user is received.
onMixedAudioFrame	Occurs when the mixed recorded and playback audio frame is received.

Raw Video Data

Method	Description
registerVideoFrameObserver	Registers a video frame observer object.

Event	Description
onCaptureVideoFrame	Occurs when the camera captured image is received.
onPreEncodeVideoFrame	Occurs each time the SDK receives a video frame before encoding.
getSmoothRenderingEnabled	Sets whether to output the acquired video frame smoothly.
onRenderVideoFrame	Processes the received image of the specified user (post-processing).
getVideoFormatPreference	Occurs each time the SDK receives a video frame and prompts you to set the video format.
getRotationApplied	Occurs each time the SDK receives a video frame and prompts you whether or not to rotate the captured video.
getMirrorApplied	Occurs each time the SDK receives a video frame and prompts you whether or not to mirror the captured video.

Media Metadata

This group of methods apply to Live Broadcast only. Do not implement getMaxMetadataSize, onReadyToSendMetadata, and onMetadataReceived in IRtcEngineEventHandler.

Method	Description
registerMediaMetadataObserver	Registers the metadata observer.

Event	Description
getMaxMetadataSize	Occurs when the SDK requests the maximum size of the metadata.
onReadyToSendMetadata	Occurs when the SDK is ready to receive and send metadata.
onMetadataReceived	Occurs when the local user receives the metadata.

Watermark

This group of methods apply to Live Broadcast only.

Method	Description
addVideoWatermark	Adds a watermark image to the local video stream.
clearVideoWatermarks	Removes the added watermark image from the video stream.

Encryption

Method	Description
setEncryptionSecret	Enables built-in encryption with an encryption password before joining a channel.
setEncryptionMode	Sets the built-in encryption mode.
registerPacketObserver	Registers a packet observer.

Audio Recorder

Method	Description
startAudioRecording	Starts an audio recording on the client.
stopAudioRecording	Stops an audio recording on the client.

Inject an Online Media Stream

• This group of methods apply to Live Broadcast only.
• We provide an advanced guide on the applicable scenarios, implementation and considerations for this group of methods. For details, see Inject Online Media Stream.

Method	Description
addInjectStreamUrl	Adds an online media stream to a live broadcast.
removeInjectStreamUrl	Removes the online media stream from a live broadcast.

Event	Description
onStreamInjectedStatus	Reports the status of the injected online media stream.

Camera Control

Method	Description
switchCamera	Switches between front and rear cameras (for Android and iOS only).

Event	Description
onCameraFocusAreaChanged	Occurs when the camera focus area changes.
onCameraExposureAreaChanged	Occurs when the camera exposure area changes.

Device Manager

This group of methods are for Windows only.

Method	Description
enumeratePlaybackDevices	Enumerates the audio playback devices.
enumerateRecordingDevices	Enumerates the audio recording devices.
setPlaybackDevice	Sets the audio playback device using the device ID.
setRecordingDevice	Sets the audio recording device using the device ID.
startPlaybackDeviceTest	Starts the audio playback device test.
stopPlaybackDeviceTest	Stops the audio playback device test.
startRecordingDeviceTest	Starts the recording device test.
stopRecordingDeviceTest	Stops the recording device test.
startAudioDeviceLoopbackTest	Starts the audio device loopback test.
stopAudioDeviceLoopbackTest	Stops the audio device loopback test.
setPlaybackDeviceVolume	Sets the volume of the audio playback device.
getPlaybackDeviceVolume	Gets the volume of the audio playback device.
setRecordingDeviceVolume	Sets the volume of the recording device.
getRecordingDeviceVolume	Gets the volume of the recording device.
setPlaybackDeviceMute	Mutes/Unmutes the audio playback device.
isApplicationMute	Gets the mute state of the application.
getPlaybackDeviceMute	Gets the mute state of the audio playback device.
setRecordingDeviceMute	Mutes/Unmutes the recording device.
getRecordingDeviceMute	Gets the mute state of the recording device.
enumerateVideoDevices	Enumerates the video devices.
startDeviceTest	Starts the video-capture device test.
stopDeviceTest	Stops the video-capture device test.
getCount	Gets the total number of indexed video devices in the system.
getDevice	Gets the video-capture device that is in use.
setDevice	Sets the device with the device ID.

Event	Description
onAudioDeviceStateChanged	Occurs when the audio device state changes.
onAudioDeviceVolumeChanged	Occurs when the volume of the playback, microphone, or application changes.
onVideoDeviceStateChanged	Occurs when the video device state changes.

Stream Message

Method	Description
createDataStream	Creates a data stream.
sendStreamMessage	Sends data stream messages.

Event	Description
onStreamMessage	Occurs when the local user receives a remote data stream within five seconds.
onStreamMessageError	Occurs when the local user fails to receive the remote data stream.

Miscellaneous Video Control

Method	Description
enableLoopbackRecording	Enables loopback recording (for macOS and Windows only).
setAudioSessionOperationRestriction	Sets the audio session’s operational restriction (for iOS only).

Miscellaneous Audio Control

Method	Description
setCameraCapturerConfiguration	Sets the camera capturer configuration.

Miscellaneous Methods

Method	Description
getCallId	Gets the current call ID.
rate	Allows the user to rate the call and is called after the call ends.
complain	Allows a user to complain about the call quality after a call ends.
getVersion	Gets the SDK version number.
setLogFile	Specifies an SDK output log file.
setLogFilter	Sets the output log level of the SDK.
setLogFileSize	Sets the log file size (KB).
getErrorDescription	Gets the warning or error description.
queryInterface	Gets the pointer to the device manager object.

Miscellaneous Events

Event	Description
onWarning	Reports a warning during SDK runtime.
onError	Reports an error during SDK runtime.
onApiCallExecuted	Occurs when a method is executed.

Customized Methods

Method	Description
setParameters	Provides the technical preview functionalities or special customizations by configuring the SDK with JSON options.