Agora C++ API Reference for All Platforms

Reports a warning during SDK runtime.

In most cases, the application can ignore the warning reported by the SDK because the SDK can usually fix the issue and resume running. For example, when losing connection with the server, the SDK may report WARN_LOOKUP_CHANNEL_TIMEOUT and automatically try to reconnect.

Parameters

warn	Warning code: WARN_CODE_TYPE.
msg	Pointer to the warning message.

Reports an error during SDK runtime.

In most cases, the SDK cannot fix the issue and resume running. The SDK requires the application to take action or informs the user about the issue.

For example, the SDK reports an ERR_START_CALL error when failing to initialize a call. The application informs the user that the call initialization failed and invokes the leaveChannel method to leave the channel.

Parameters

err	Error code: ERROR_CODE_TYPE.
msg	Pointer to the error message.

Occurs when a user joins a channel.

This callback notifies the application that a user joins a specified channel when the application calls the joinChannel method.

The channel name assignment is based on channelName specified in the joinChannel method.

If the uid is not specified in the joinChannel method, the server automatically assigns a uid.

Parameters

channel	Pointer to the channel name.
uid	User ID of the user joining the channel.
elapsed	Time elapsed (ms) from the user calling the joinChannel method until the SDK triggers this callback.

Occurs when a user rejoins the channel after disconnection due to network problems.

When a user loses connection with the server because of network problems, the SDK automatically tries to reconnect and triggers this callback upon reconnection.

Parameters

channel	Pointer to the channel name.
uid	User ID of the user rejoining the channel.
elapsed	Time elapsed (ms) from starting to reconnect until the SDK triggers this callback.

Occurs when a user leaves the channel.

This callback notifies the application that a user leaves the channel when the application calls the leaveChannel method.

The application gets information, such as the call duration and statistics.

Parameters

stats

Pointer to the statistics of the call: RtcStats.

Occurs when the user role switches successfully in the interactive live streaming.

In the LIVE_BROADCASTING channel profile, when the local user successfully calls setClientRole to switch their user role after joining the channel, for example, from a host to an audience member or vice versa, the SDK triggers this callback to report the user role before and after the switch.

Parameters

oldRole	Role that the user switches from: CLIENT_ROLE_TYPE.
newRole	Role that the user switches to: CLIENT_ROLE_TYPE.

Occurs when the user role switch fails in the interactive live streaming.

Since

v3.7.0

In the LIVE_BROADCASTING channel profile, when the local user calls setClientRole to switch their user role after joining the channel but the switch fails, the SDK triggers this callback to report the reason for the failure and the current user role.

Parameters

reason	The reason for the user role switch failure. See CLIENT_ROLE_CHANGE_FAILED_REASON.
currentRole	The current user role. See CLIENT_ROLE_TYPE.

Occurs when a remote user (COMMUNICATION)/ host (LIVE_BROADCASTING) joins the channel.

• COMMUNICATION profile: This callback notifies the application that another user joins the channel. If other users are already in the channel, the SDK also reports to the application on the existing users.
• LIVE_BROADCASTING profile: This callback notifies the application that the host joins the channel. If other hosts are already in the channel, the SDK also reports to the application on the existing hosts. We recommend limiting the number of hosts to 17.

The SDK triggers this callback under one of the following circumstances:

• A remote user/host joins the channel by calling the joinChannel method.
• A remote user switches the user role to the host by calling the setClientRole method after joining the channel.
• A remote user/host rejoins the channel after a network interruption.
• The host injects an online media stream into the channel by calling the addInjectStreamUrl method.

Note

In the LIVE_BROADCASTING profile:

• The host receives this callback when another host joins the channel.
• The audience in the channel receives this callback when a new host joins the channel.
• When a web application joins the channel, the SDK triggers this callback as long as the web application publishes streams.

Parameters

uid	User ID of the user or host joining the channel.
elapsed	Time delay (ms) from the local user calling the joinChannel method until the SDK triggers this callback.

Occurs when a remote user (COMMUNICATION)/ host (LIVE_BROADCASTING) leaves the channel.

Reasons why the user is offline:

• Leave the channel: When the user/host leaves the channel, the user/host sends a goodbye message. When the message is received, the SDK assumes that the user/host leaves the channel.
• Drop offline: When no data packet of the user or host is received for a certain period of time, the SDK assumes that the user/host drops offline. Unreliable network connections may lead to false detections, so we recommend using the Agora RTM SDK for more reliable offline detection.

Parameters

uid	User ID of the user leaving the channel or going offline.
reason	Reason why the user is offline: USER_OFFLINE_REASON_TYPE.

Reports the proxy connection state.

Since

v3.6.2

You can use this callback to listen for the state of the SDK connecting to a proxy. For example, when a user calls setCloudProxy and joins a channel successfully, the SDK triggers this callback to report the user ID, the proxy type connected, and the time elapsed from the user calling joinChannel until this callback is triggered.

Parameters

channel	The channel name.
uid	The user ID.
proxyType	The proxy type connected. See PROXY_TYPE.
localProxyIp	Reserved for future use.
elapsed	The time elapsed (ms) from the user calling joinChannel until this callback is triggered.

Reports the last mile network quality of the local user once every two seconds before the user joins the channel.

Last mile refers to the connection between the local device and Agora's edge server. After the application calls the enableLastmileTest method, this callback reports once every two seconds the uplink and downlink last mile network conditions of the local user before the user joins the channel.

Parameters

quality

The last mile network quality: QUALITY_TYPE.

Reports the last-mile network probe result.

The SDK triggers this callback within 30 seconds after the app calls the startLastmileProbeTest method.

Parameters

result

The uplink and downlink last-mile network probe test result. See LastmileProbeResult.

Deprecated:

Occurs when the connection between the SDK and the server is interrupted.

Deprecated as of v2.3.2. Replaced by the onConnectionStateChanged(CONNECTION_STATE_RECONNECTING, CONNECTION_CHANGED_INTERRUPTED) callback.

The SDK triggers this callback when it loses connection with the server for more than four seconds after the connection is established.

After triggering this callback, the SDK tries reconnecting to the server. You can use this callback to implement pop-up reminders.

This callback is different from onConnectionLost:

• The SDK triggers the onConnectionInterrupted callback when it loses connection with the server for more than four seconds after it successfully joins the channel.
• The SDK triggers the onConnectionLost callback when it loses connection with the server for more than 10 seconds, whether or not it joins the channel.

If the SDK fails to rejoin the channel 20 minutes after being disconnected from Agora's edge server, the SDK stops rejoining the channel.

Occurs when the SDK cannot reconnect to Agora's edge server 10 seconds after its connection to the server is interrupted.

The SDK triggers this callback when it cannot connect to the server 10 seconds after calling the joinChannel method, whether or not it is in the channel.

This callback is different from onConnectionInterrupted:

• The SDK triggers the onConnectionInterrupted callback when it loses connection with the server for more than four seconds after it successfully joins the channel.
• The SDK triggers the onConnectionLost callback when it loses connection with the server for more than 10 seconds, whether or not it joins the channel.

If the SDK fails to rejoin the channel 20 minutes after being disconnected from Agora's edge server, the SDK stops rejoining the channel.

Deprecated:

Deprecated as of v2.3.2. Replaced by the onConnectionStateChanged(CONNECTION_STATE_FAILED, CONNECTION_CHANGED_BANNED_BY_SERVER) callback.

Occurs when your connection is banned by the Agora Server.

Occurs when a method is executed by the SDK.

Parameters

err	The error code (ERROR_CODE_TYPE) returned by the SDK when a method call fails. If the SDK returns 0, then the method call is successful.
api	Pointer to the method executed by the SDK.
result	Pointer to the result of the method call.

Occurs when the token expires.

After a token is specified by calling the joinChannel method, if the SDK losses connection with the Agora server due to network issues, the token may expire after a certain period of time and a new token may be required to reconnect to the server.

Once you receive this callback, generate a new token on your app server, and call renewToken to pass the new token to the SDK.

Occurs when the token expires in 30 seconds.

The user becomes offline if the token used in the joinChannel method expires. The SDK triggers this callback 30 seconds before the token expires to remind the application to get a new token. Upon receiving this callback, generate a new token on the server and call the renewToken method to pass the new token to the SDK.

Parameters

token

The token that expires in 30 seconds.

Deprecated:

Reports the statistics of the audio stream from each remote user/host.

Deprecated as of v2.3.2. Use the onRemoteAudioStats callback instead.

The SDK triggers this callback once every two seconds to report the audio quality of each remote user/host sending an audio stream. If a channel has multiple users/hosts sending audio streams, the SDK triggers this callback as many times.

Parameters

uid	User ID of the speaker.
quality	Audio quality of the user: QUALITY_TYPE.
delay	Time delay (ms) of sending the audio packet from the sender to the receiver, including the time delay of audio sampling pre-processing, transmission, and the jitter buffer.
lost	Packet loss rate (%) of the audio packet sent from the sender to the receiver.

Reports the statistics of the current call.

The SDK triggers this callback once every two seconds after the user joins the channel.

Parameters

stats

Statistics of the IRtcEngine: RtcStats.

Reports the last mile network quality of each user in the channel once every two seconds.

Last mile refers to the connection between the local device and Agora's edge server. This callback reports once every two seconds the last mile network conditions of each user in the channel. If a channel includes multiple users, the SDK triggers this callback as many times.

Note

txQuality is UNKNOWN when the user is not sending a stream; rxQuality is UNKNOWN when the user is not receiving a stream.

Parameters

uid	User ID. The network quality of the user with this uid is reported. If uid is 0, the local network quality is reported.
txQuality	Uplink transmission quality rating of the user in terms of the transmission bitrate, packet loss rate, average RTT (Round-Trip Time), and jitter of the uplink network. txQuality is a quality rating helping you understand how well the current uplink network conditions can support the selected VideoEncoderConfiguration. For example, a 1000 Kbps uplink network may be adequate for video frames with a resolution of 640 * 480 and a frame rate of 15 fps in the LIVE_BROADCASTING profile, but may be inadequate for resolutions higher than 1280 * 720. See QUALITY_TYPE.
rxQuality	Downlink network quality rating of the user in terms of the packet loss rate, average RTT, and jitter of the downlink network. See QUALITY_TYPE.

Reports the statistics of the local video stream.

The SDK triggers this callback once every two seconds for each user/host. If there are multiple users/hosts in the channel, the SDK triggers this callback as many times.

Note

If you have called the enableDualStreamMode method, the onLocalVideoStats callback reports the statistics of the high-video stream (high bitrate, and high-resolution video stream).

Parameters

stats

Statistics of the local video stream. See LocalVideoStats.

Reports the statistics of the video stream from each remote user/host.

The SDK triggers this callback once every two seconds for each remote user/host. If a channel includes multiple remote users, the SDK triggers this callback as many times.

Parameters

stats

Statistics of the remote video stream. See RemoteVideoStats.

Reports the statistics of the local audio stream.

The SDK triggers this callback once every two seconds.

Parameters

stats

The statistics of the local audio stream. See LocalAudioStats.

Reports the statistics of the audio stream from each remote user/host.

This callback replaces the onAudioQuality callback.

The SDK triggers this callback once every two seconds for each remote user/host. If a channel includes multiple remote users, the SDK triggers this callback as many times.

Parameters

stats

Pointer to the statistics of the received remote audio streams. See RemoteAudioStats.

Occurs when the local audio state changes. This callback indicates the state change of the local audio stream, including the state of the audio capturing and encoding, and allows you to troubleshoot issues when exceptions occur.

Note

When the state is LOCAL_AUDIO_STREAM_STATE_FAILED (3), see the error parameter for details.

Parameters

state	State of the local audio. See LOCAL_AUDIO_STREAM_STATE.
error	The error information of the local audio. See LOCAL_AUDIO_STREAM_ERROR.

Occurs when the remote audio state changes.

This callback indicates the state change of the remote audio stream.

Note

This callback can be inaccurate when the number of users (in the COMMUNICATION profile) or hosts (in the LIVE_BROADCASTING profile) in a channel exceeds 17.

Parameters

uid	ID of the remote user whose audio state changes.
state	State of the remote audio. See REMOTE_AUDIO_STATE.
reason	The reason of the remote audio state change. See REMOTE_AUDIO_STATE_REASON.
elapsed	Time elapsed (ms) from the local user calling the joinChannel method until the SDK triggers this callback.

Occurs when the audio publishing state changes.

Since

v3.1.0

This callback indicates the publishing state change of the local audio stream.

Parameters

channel	The channel name.
oldState	The previous publishing state. For details, see STREAM_PUBLISH_STATE.
newState	The current publishing state. For details, see STREAM_PUBLISH_STATE.
elapseSinceLastState	The time elapsed (ms) from the previous state to the current state.

Occurs when the video publishing state changes.

Since

v3.1.0

This callback indicates the publishing state change of the local video stream.

Parameters

channel	The channel name.
oldState	The previous publishing state. For details, see STREAM_PUBLISH_STATE.
newState	The current publishing state. For details, see STREAM_PUBLISH_STATE.
elapseSinceLastState	The time elapsed (ms) from the previous state to the current state.

Occurs when the audio subscribing state changes.

Since

v3.1.0

This callback indicates the subscribing state change of a remote audio stream.

Parameters

channel	The channel name.
uid	The ID of the remote user.
oldState	The previous subscribing state. For details, see STREAM_SUBSCRIBE_STATE.
newState	The current subscribing state. For details, see STREAM_SUBSCRIBE_STATE.
elapseSinceLastState	The time elapsed (ms) from the previous state to the current state.

Occurs when the audio subscribing state changes.

Since

v3.1.0

This callback indicates the subscribing state change of a remote video stream.

Parameters

channel	The channel name.
uid	The ID of the remote user.
oldState	The previous subscribing state. For details, see STREAM_SUBSCRIBE_STATE.
newState	The current subscribing state. For details, see STREAM_SUBSCRIBE_STATE.
elapseSinceLastState	The time elapsed (ms) from the previous state to the current state.

Reports the volume information of users.

By default, this callback is disabled. You can enable it by calling enableAudioVolumeIndication. Once this callback is enabled and users send streams in the channel, the SDK triggers the onAudioVolumeIndication callback at the time interval set in enableAudioVolumeIndication.

The SDK triggers two independent onAudioVolumeIndication callbacks simultaneously, which separately report the volume information of the local user who sends a stream and the remote users (up to three) whose instantaneous volumes are the highest.

Note

After you enable this callback, calling muteLocalAudioStream affects the SDK's behavior as follows:

• If the local user calls muteLocalAudioStream, the SDK stops triggering the local user's callback.
• 20 seconds after a remote user whose volume is one of the three highest calls muteLocalAudioStream, the remote users' callback excludes this remote user's information; 20 seconds after all remote users call muteLocalAudioStream, the SDK stops triggering the remote users' callback.

Parameters

speakers

The volume information of users. See AudioVolumeInfo.

An empty speakers array in the callback indicates that no remote user is in the channel or sending a stream at the moment.

Parameters

speakerNumber	Total number of users. In the local user's callback, when the local user sends a stream, speakerNumber = 1. In the remote users' callback, the value ranges between 0 and 3. If the number of remote users who send streams is greater than or equal to three, speakerNumber = 3.
totalVolume	Total volume after audio mixing. The value ranges between 0 (lowest volume) and 255 (highest volume). In the local user's callback, totalVolume is the volume of the local user who sends a stream. In the remote users' callback, totalVolume is the sum of the volume of all remote users (up to three) whose instantaneous volumes are the highest.

If the user calls startAudioMixing, totalVolume is the sum of the voice volume and audio-mixing volume.

Reports the voice pitch of the local user.

Since

v3.7.0

After the local audio capture is enabled, and you call enableLocalVoicePitchCallback , the SDK triggers this callback at the time interval set in enableLocalVoicePitchCallback.

Note

After this callback is enabled, if the user disables the local audio capture, for example, by calling enableLocalAudio(false), the SDK immediately stops sending the onLocalVoicePitchInHz callback.

Parameters

pitchInHz

The voice pitch (Hz) of the local user.

Reports the result of an audio device test.

Since

v3.6.2

After successfully calling startRecordingDeviceTest, startPlaybackDeviceTest, or startAudioDeviceLoopbackTest to start an audio device test, the SDK triggers the onAudioDeviceTestVolumeIndication callback at the set time interval to report the volume information of the audio device tested.

Parameters

volumeType	The volume type. See AudioDeviceTestVolumeType.
volume	The volume, in the range of [0,255].

Occurs when the most active remote speaker is detected.

After a successful call of enableAudioVolumeIndication, the SDK continuously detects which remote user has the loudest volume. During the current period, the remote user, who is detected as the loudest for the most times, is the most active user.

When the number of user is no less than two and an active speaker exists, the SDK triggers this callback and reports the uid of the most active speaker.

• If the most active speaker is always the same user, the SDK triggers this callback only once.
• If the most active speaker changes to another user, the SDK triggers this callback again and reports the uid of the new active speaker.

Parameters

uid	The user ID of the most active remote speaker.

Deprecated:

Occurs when the video stops playing.

The application can use this callback to change the configuration of the view (for example, displaying other pictures in the view) after the video stops playing.

Deprecated as of v2.4.1. Use LOCAL_VIDEO_STREAM_STATE_STOPPED(0) in the onLocalVideoStateChanged callback instead.

Occurs when the first local video frame is displayed/rendered on the local video view.

Parameters

width	Width (px) of the first local video frame.
height	Height (px) of the first local video frame.
elapsed	Time elapsed (ms) from the local user calling the joinChannel method until the SDK triggers this callback. If you call the startPreview method before calling the joinChannel method, then elapsed is the time elapsed from calling the startPreview method until the SDK triggers this callback.

Occurs when the first video frame is published.

Since

v3.1.0

The SDK triggers this callback under one of the following circumstances:

• The local client enables the video module and calls joinChannel successfully.
• The local client calls muteLocalVideoStream(true) and muteLocalVideoStream(false) in sequence.
• The local client calls disableVideo and enableVideo in sequence.
• The local client calls pushVideoFrame to successfully push the video frame to the SDK.

Parameters

elapsed

The time elapsed (ms) from the local client calling joinChannel until the SDK triggers this callback.

Occurs when the first remote video frame is received and decoded.

This callback is triggered in either of the following scenarios:

• The remote user joins the channel and sends the video stream.
• The remote user stops sending the video stream and re-sends it after 15 seconds. Reasons for such an interruption include:
  • The remote user leaves the channel.
  • The remote user drops offline.
  • The remote user calls the muteLocalVideoStream method to stop sending the video stream.
  • The remote user calls the disableVideo method to disable video.

The application can configure the user view settings in this callback.

Parameters

uid	User ID of the remote user sending the video stream.
width	Width (px) of the video stream.
height	Height (px) of the video stream.
elapsed	Time elapsed (ms) from the local user calling the joinChannel method until the SDK triggers this callback.

Occurs when the first remote video frame is rendered.

The SDK triggers this callback when the first frame of the remote video is displayed in the user's video window. The application can get the time elapsed from a user joining the channel until the first video frame is displayed.

Parameters

uid	User ID of the remote user sending the video stream.
width	Width (px) of the video frame.
height	Height (px) of the video stream.
elapsed	Time elapsed (ms) from the local user calling the joinChannel method until the SDK triggers this callback.

Occurs when a remote user's audio stream playback pauses/resumes.

The SDK triggers this callback when the remote user stops or resumes sending the audio stream by calling the muteLocalAudioStream method.

Note

This callback can be inaccurate when the number of users (in the COMMUNICATION profile) or hosts (in the LIVE_BROADCASTING profile) in a channel exceeds 17.

Parameters

uid	User ID of the remote user.
muted	Whether the remote user's audio stream is muted/unmuted: true: Muted. false: Unmuted.

Occurs when a remote user stops or resumes publishing the video stream.

When a remote user calls muteLocalVideoStream to stop or resume publishing the video stream, the SDK triggers this callback to report the state of the remote user's publishing stream to the local user.

Note

This callback can be inaccurate when the number of users (in the COMMUNICATION profile) or hosts (in the LIVE_BROADCASTING profile) in a channel exceeds 17.

Parameters

uid	The user ID of the remote user.
muted	Whether the remote user stops publishing the video stream: true: Stop publishing the video stream. false: Publish the video stream.

Occurs when a specific remote user enables/disables the video module.

Once the video module is disabled, the remote user can only use a voice call. The remote user cannot send or receive any video from other users.

The SDK triggers this callback when the remote user enables or disables the video module by calling the enableVideo or disableVideo method.

Note

This callback returns invalid when the number of users in a channel exceeds 20.

Parameters

uid	User ID of the remote user.
enabled	Whether the remote user enables/disables the video module: true: Enable. The remote user can enter a video session. false: Disable. The remote user can only enter a voice session, and cannot send or receive any video stream.

Occurs when the audio device state changes (for macOS and Windows only).

This callback notifies the application that the system's audio device state is changed. For example, a headset is unplugged from the device.

Parameters

deviceId	Pointer to the device ID.
deviceType	Device type: MEDIA_DEVICE_TYPE.
deviceState	The state of the device: On macOS: 0: The device is ready for use. 8: The device is not connected. On Windows: MEDIA_DEVICE_STATE_TYPE.

Occurs when the volume of the playback device, microphone, or application changes.

Parameters

deviceType	Device type: MEDIA_DEVICE_TYPE.
volume	Volume of the device. The value ranges between 0 and 255.
muted	true: The audio device is muted. false: The audio device is not muted.

Deprecated:

Occurs when the camera turns on and is ready to capture the video.

If the camera fails to turn on, fix the error reported in the onError callback.

Deprecated as of v2.4.1. Use LOCAL_VIDEO_STREAM_STATE_CAPTURING (1) in the onLocalVideoStateChanged callback instead.

Occurs when the camera focus area changes.

The SDK triggers this callback when the local user changes the camera focus position by calling the setCameraFocusPositionInPreview method.

Note

This callback is for Android and iOS only.

Parameters

x	x coordinate of the changed camera focus area.
y	y coordinate of the changed camera focus area.
width	Width of the changed camera focus area.
height	Height of the changed camera focus area.

Reports the face detection result of the local user. Applies to Android and iOS only.

Since

v3.0.1

Once you enable face detection by calling enableFaceDetection(true), you can get the following information on the local user in real-time:

• The width and height of the local video.
• The position of the human face in the local view.
• The distance between the human face and the device screen. This value is based on the fitting calculation of the local video size and the position of the human face.

Note

• If the SDK does not detect a face, it reduces the frequency of this callback to reduce power consumption on the local device.
• The SDK stops triggering this callback when a human face is in close proximity to the screen.
• On Android, the distance value reported in this callback may be slightly different from the actual distance. Therefore, Agora does not recommend using it for accurate calculation.

Parameters

imageWidth	The width (px) of the local video.
imageHeight	The height (px) of the local video.
vecRectangle	The position and size of the human face on the local video: x: The x coordinate (px) of the human face in the local view. Taking the top left corner of the view as the origin, the x coordinate represents the relative lateral displacement of the top left corner of the human face to the origin. y: The y coordinate (px) of the human face in the local view. Taking the top left corner of the view as the origin, the y coordinate represents the relative longitudinal displacement of the top left corner of the human face to the origin. width: The width (px) of the human face in the captured video. height: The height (px) of the human face in the captured video.
vecDistance	The distance (cm) between the human face and the screen.
numFaces	The number of faces detected. If the value is 0, it means that no human face is detected.

Occurs when the camera exposure area changes.

The SDK triggers this callback when the local user changes the camera exposure position by calling the setCameraExposurePosition method.

Note

This callback is for Android and iOS only.

Parameters

x	x coordinate of the changed camera exposure area.
y	y coordinate of the changed camera exposure area.
width	Width of the changed camera exposure area.
height	Height of the changed camera exposure area.

Occurs when the audio mixing file playback finishes.

You can start an audio mixing file playback by calling the startAudioMixing method. The SDK triggers this callback when the audio mixing file playback finishes.

If the startAudioMixing method call fails, an error code returns in the onError callback.

Occurs when the state of the local user's music file changes.

Since

v3.4.0

When the playback state of the local user's music file changes, the SDK triggers this callback and reports the current playback state and the reason for the change.

Parameters

state	The current music file playback state. See AUDIO_MIXING_STATE_TYPE.
reason	The reason for the change of the music file playback state. See AUDIO_MIXING_REASON_TYPE.

Occurs when a remote user starts audio mixing.

When a remote user calls startAudioMixing to play the background music, the SDK reports this callback.

Occurs when a remote user finishes audio mixing.

Reports the information of an audio file.

Since

v3.5.1

After successfully calling getAudioFileInfo, the SDK triggers this callback to report the information of the audio file, such as the file path and duration.

Parameters

info	The information of an audio file. See AudioFileInfo.
error	The information acquisition state. See AUDIO_FILE_INFO_ERROR.

Occurs when the local audio effect playback finishes.

The SDK triggers this callback when the local audio effect file playback finishes.

Parameters

soundId

ID of the local audio effect. Each local audio effect has a unique ID.

Occurs when the SDK decodes the first remote audio frame for playback.

Deprecated:

v3.0.0

This callback is deprecated. Use onRemoteAudioStateChanged instead.

This callback is triggered in either of the following scenarios:

• The remote user joins the channel and sends the audio stream.
• The remote user stops sending the audio stream and re-sends it after 15 seconds. Reasons for such an interruption include:
  • The remote user leaves channel.
  • The remote user drops offline.
  • The remote user calls the muteLocalAudioStream method to stop sending the local audio stream.
  • The remote user calls the disableAudio method to disable audio.

Parameters

uid	User ID of the remote user sending the audio stream.
elapsed	Time elapsed (ms) from the local user calling the joinChannel method until the SDK triggers this callback.

Occurs when the video device state changes (for macOS and Windows only).

Note

On a Windows device with an external camera for video capturing, the video disables once the external camera is unplugged.

Parameters

deviceId	Pointer to the device ID of the video device that changes state.
deviceType	Device type: MEDIA_DEVICE_TYPE.
deviceState	The state of the device: On macOS: 0: The device is ready for use. 8: The device is not connected. On Windows: MEDIA_DEVICE_STATE_TYPE.

Occurs when the local video stream state changes.

This callback indicates the state of the local video stream, including camera capturing and video encoding, and allows you to troubleshoot issues when exceptions occur.

The SDK triggers the onLocalVideoStateChanged(LOCAL_VIDEO_STREAM_STATE_FAILED, LOCAL_VIDEO_STREAM_ERROR_CAPTURE_FAILURE) callback in the following situations:

• The application exits to the background, and the system recycles the camera.
• The camera starts normally, but the captured video is not output for four seconds.

When the camera outputs the captured video frames, if all the video frames are the same for 15 consecutive frames, the SDK triggers the onLocalVideoStateChanged(LOCAL_VIDEO_STREAM_STATE_CAPTURING, LOCAL_VIDEO_STREAM_ERROR_CAPTURE_FAILURE) callback. Note that the video frame duplication detection is only available for video frames with a resolution greater than 200 × 200, a frame rate greater than or equal to 10 fps, and a bitrate less than 20 Kbps.

Note

For some device models, the SDK will not trigger this callback when the state of the local video changes while the local video capturing device is in use, so you have to make your own timeout judgment.

Parameters

localVideoState	State type LOCAL_VIDEO_STREAM_STATE.
error	The detailed error information: LOCAL_VIDEO_STREAM_ERROR.

Occurs when the video size or rotation of a specified user changes.

Parameters

uid	User ID of the remote user or local user (0) whose video size or rotation changes.
width	New width (pixels) of the video.
height	New height (pixels) of the video.
rotation	New rotation of the video [0 to 360).

Occurs when the remote video state changes.

Note

This callback can be inaccurate when the number of users (in the COMMUNICATION profile) or hosts (in the LIVE_BROADCASTING profile) in a channel exceeds 17.

Parameters

uid	ID of the remote user whose video state changes.
state	State of the remote video. See REMOTE_VIDEO_STATE.
reason	The reason of the remote video state change. See REMOTE_VIDEO_STATE_REASON.
elapsed	Time elapsed (ms) from the local user calling the joinChannel method until the SDK triggers this callback.

Occurs when a specified remote user enables/disables the local video capturing function.

This callback is only applicable to the scenario when the user only wants to watch the remote video without sending any video stream to the other user.

The SDK triggers this callback when the remote user resumes or stops capturing the video stream by calling the enableLocalVideo method.

Parameters

uid	User ID of the remote user.
enabled	Whether the specified remote user enables/disables the local video capturing function: true: Enable. Other users in the channel can see the video of this remote user. false: Disable. Other users in the channel can no longer receive the video stream from this remote user, while this remote user can still receive the video streams from other users.

Occurs when the local user receives the data stream from the remote user within five seconds.

The SDK triggers this callback when the local user receives the stream message that the remote user sends by calling the sendStreamMessage method.

Parameters

uid	User ID of the remote user sending the message.
streamId	Stream ID.
data	Pointer to the data received by the local user.
length	Length of the data in bytes.

Occurs when the local user does not receive the data stream from the remote user within five seconds.

The SDK triggers this callback when the local user fails to receive the stream message that the remote user sends by calling the sendStreamMessage method.

Parameters

uid	User ID of the remote user sending the message.
streamId	Stream ID.
code	Error code: ERROR_CODE_TYPE.
missed	Number of lost messages.
cached	Number of incoming cached messages when the data stream is interrupted.

Occurs when the media engine loads.

Occurs when the media engine call starts.

Reports whether the super resolution feature is successfully enabled. (beta feature)

Since

v3.5.1

After calling enableRemoteSuperResolution, the SDK triggers this callback to report whether super resolution is successfully enabled. If it is not successfully enabled, use reason for troubleshooting.

Parameters

uid	The user ID of the remote user.
enabled	Whether super resolution is successfully enabled: true: Super resolution is successfully enabled. false: Super resolution is not successfully enabled.
reason	The reason why super resolution is not successfully enabled or the message that confirms success. See SUPER_RESOLUTION_STATE_REASON.

Reports whether the virtual background is successfully enabled.

Since

v3.4.5

After you call enableVirtualBackground, the SDK triggers this callback to report whether the virtual background is successfully enabled.

Note

If the background image customized in the virtual background is in PNG or JPG format, the triggering of this callback is delayed until the image is read.

Parameters

enabled	Whether the virtual background is successfully enabled: true: The virtual background is successfully enabled. false: The virtual background is not successfully enabled.
reason	The reason why the virtual background is not successfully enabled or the message that confirms success. See VIRTUAL_BACKGROUND_SOURCE_STATE_REASON.

Reports the result of taking a video snapshot.

Since

v3.5.2

After a successful takeSnapshot method call, the SDK triggers this callback to report whether the snapshot is successfully taken as well as the details for the snapshot taken.

Parameters

channel	The channel name.
uid	The user ID of the user. A uid of 0 indicates the local user.
filePath	The local path of the snapshot.
width	The width (px) of the snapshot.
height	The height (px) of the snapshot.
errCode	The message that confirms success or the reason why the snapshot is not successfully taken: 0: Success. < 0: Failure: -1: The SDK fails to write data to a file or encode a JPEG image. -2: The SDK does not find the video stream of the specified user within one second after the takeSnapshot method call succeeds.

Occurs when the state of the media stream relay changes.

The SDK returns the state of the current media relay with any error message.

Parameters

state	The state code in CHANNEL_MEDIA_RELAY_STATE.
code	The error code in CHANNEL_MEDIA_RELAY_ERROR.

Reports events during the media stream relay.

Parameters

code	The event code in CHANNEL_MEDIA_RELAY_EVENT.

Occurs when the engine sends the first local audio frame.

Deprecated:

Deprecated as of v3.1.0. Use the onFirstLocalAudioFramePublished callback instead.

Parameters

elapsed

Time elapsed (ms) from the local user calling joinChannel until the SDK triggers this callback.

Occurs when the first audio frame is published.

Since

v3.1.0

The SDK triggers this callback under one of the following circumstances:

• The local client enables the audio module and calls joinChannel successfully.
• The local client calls muteLocalAudioStream(true) and muteLocalAudioStream(false) in sequence.
• The local client calls disableAudio and enableAudio in sequence.
• The local client calls pushAudioFrame to successfully push the video frame to the SDK.

Parameters

elapsed

The time elapsed (ms) from the local client calling joinChannel until the SDK triggers this callback.

Occurs when the engine receives the first audio frame from a specific remote user.

Deprecated:

v3.0.0

This callback is deprecated. Use onRemoteAudioStateChanged instead.

Parameters

uid	User ID of the remote user.
elapsed	Time elapsed (ms) from the remote user calling joinChannel until the SDK triggers this callback.

Occurs when the state of the RTMP or RTMPS streaming changes.

When the CDN live streaming state changes, the SDK triggers this callback to report the current state and the reason why the state has changed.

When exceptions occur, you can troubleshoot issues by referring to the detailed error descriptions in the errCode parameter.

Parameters

url	The CDN streaming URL.
state	The RTMP or RTMPS streaming state. See: RTMP_STREAM_PUBLISH_STATE.
errCode	The detailed error information for streaming. See: RTMP_STREAM_PUBLISH_ERROR_TYPE.

Reports events during the RTMP or RTMPS streaming.

Since

v3.1.0

Parameters

url	The RTMP or RTMPS streaming URL.
eventCode	The event code. See RTMP_STREAMING_EVENT

Deprecated:

This method is deprecated, use the onRtmpStreamingStateChanged callback instead.

Reports the result of calling the addPublishStreamUrl method. (CDN live only.)

Parameters

url

The CDN streaming URL.

error

Error code: ERROR_CODE_TYPE. Main errors include: ERR_OK (0): The publishing succeeds. ERR_FAILED (1): The publishing fails. ERR_INVALID_ARGUMENT (-2): Invalid argument used. If, for example, you did not call setLiveTranscoding to configure LiveTranscoding before calling addPublishStreamUrl, the SDK reports ERR_INVALID_ARGUMENT. ERR_TIMEDOUT (-10): The publishing timed out. ERR_ALREADY_IN_USE (-19): The chosen URL address is already in use for CDN live streaming. ERR_ENCRYPTED_STREAM_NOT_ALLOWED_PUBLISH (130): You cannot publish an encrypted stream. ERR_PUBLISH_STREAM_CDN_ERROR (151) ERR_PUBLISH_STREAM_NUM_REACH_LIMIT (152) ERR_PUBLISH_STREAM_NOT_AUTHORIZED (153) ERR_PUBLISH_STREAM_INTERNAL_SERVER_ERROR (154) ERR_PUBLISH_STREAM_FORMAT_NOT_SUPPORTED (156)

Deprecated:

This method is deprecated, use the onRtmpStreamingStateChanged callback instead.

Reports the result of calling the removePublishStreamUrl method. (CDN live only.)

This callback indicates whether you have successfully removed an RTMP or RTMPS stream from the CDN.

Parameters

url	The CDN streaming URL.

Occurs when the publisher's transcoding is updated.

When the LiveTranscoding class in the setLiveTranscoding method updates, the SDK triggers the onTranscodingUpdated callback to report the update information to the local host.

Note

If you call the setLiveTranscoding method to set the LiveTranscoding class for the first time, the SDK does not trigger the onTranscodingUpdated callback.

Occurs when a voice or video stream URL address is added to the interactive live streaming.

Warning

Agora will soon stop the service for injecting online media streams on the client. If you have not implemented this service, Agora recommends that you do not use it.

Parameters

url	Pointer to the URL address of the externally injected stream.
uid	User ID.
status	State of the externally injected stream: INJECT_STREAM_STATUS.

Occurs when the local audio route changes.

Note

This callback applies to Android, iOS and macOS only.

Parameters

routing

The current audio routing. See: AUDIO_ROUTE_TYPE.

Occurs when the published media stream falls back to an audio-only stream due to poor network conditions or switches back to the video after the network conditions improve.

If you call setLocalPublishFallbackOption and set option as STREAM_FALLBACK_OPTION_AUDIO_ONLY, the SDK triggers this callback when the published stream falls back to audio-only mode due to poor uplink conditions, or when the audio stream switches back to the video after the uplink network condition improves.

Note

If the local stream fallbacks to the audio-only stream, the remote user receives the onUserMuteVideo callback.

Parameters

isFallbackOrRecover

Whether the published stream falls back to audio-only or switches back to the video: true: The published stream falls back to audio-only due to poor network conditions. false: The published stream switches back to the video after the network conditions improve.

Occurs when the remote media stream falls back to audio-only stream due to poor network conditions or switches back to the video stream after the network conditions improve.

If you call setRemoteSubscribeFallbackOption and set option as STREAM_FALLBACK_OPTION_AUDIO_ONLY, the SDK triggers this callback when the remote media stream falls back to audio-only mode due to poor downlink conditions, or when the remote media stream switches back to the video after the downlink network condition improves.

Note

Once the remote media stream switches to the low stream due to poor network conditions, you can monitor the stream switch between a high and low stream in the RemoteVideoStats callback.

Parameters

uid	ID of the remote user sending the stream.
isFallbackOrRecover	Whether the remotely subscribed media stream falls back to audio-only or switches back to the video: true: The remotely subscribed media stream falls back to audio-only due to poor network conditions. false: The remotely subscribed media stream switches back to the video stream after the network conditions improved.

Reports the transport-layer statistics of each remote audio stream.

Deprecated:

This callback is deprecated and replaced by the onRemoteAudioStats callback.

This callback reports the transport-layer statistics, such as the packet loss rate and network time delay, once every two seconds after the local user receives an audio packet from a remote user.

Parameters

uid	User ID of the remote user sending the audio packet.
delay	Network time delay (ms) from the remote user sending the audio packet to the local user.
lost	Packet loss rate (%) of the audio packet sent from the remote user.
rxKBitRate	Received bitrate (Kbps) of the audio packet sent from the remote user.

Reports the transport-layer statistics of each remote video stream.

Deprecated:

This callback is deprecated and replaced by the onRemoteVideoStats callback.

This callback reports the transport-layer statistics, such as the packet loss rate and network time delay, once every two seconds after the local user receives a video packet from a remote user.

Parameters

uid	User ID of the remote user sending the video packet.
delay	Network time delay (ms) from the remote user sending the video packet to the local user.
lost	Packet loss rate (%) of the video packet sent from the remote user.
rxKBitRate	Received bitrate (Kbps) of the video packet sent from the remote user.

Occurs when the microphone is enabled/disabled.

Deprecated:

v2.9.0

The onMicrophoneEnabled callback is deprecated. Use LOCAL_AUDIO_STREAM_STATE_STOPPED (0) or LOCAL_AUDIO_STREAM_STATE_RECORDING (1) in the onLocalAudioStateChanged callback instead.

The SDK triggers this callback when the local user resumes or stops capturing the local audio stream by calling the enableLocalAudio method.

Parameters

enabled

Whether the microphone is enabled/disabled: true: Enabled. false: Disabled.

Occurs when the connection state between the SDK and the server changes.

Parameters

state	See CONNECTION_STATE_TYPE.
reason	See CONNECTION_CHANGED_REASON_TYPE.

Occurs when the local network type changes.

When the network connection is interrupted, this callback indicates whether the interruption is caused by a network type change or poor network conditions.

Parameters

type	See NETWORK_TYPE.

Occurs when the local user successfully registers a user account by calling the registerLocalUserAccount method or joins a channel by calling the joinChannelWithUserAccount method.This callback reports the user ID and user account of the local user.

Parameters

uid	The ID of the local user.
userAccount	The user account of the local user.

Occurs when the SDK gets the user ID and user account of the remote user.

After a remote user joins the channel, the SDK gets the UID and user account of the remote user, caches them in a mapping table object (userInfo), and triggers this callback on the local client.

Parameters

uid	The ID of the remote user.
info	The UserInfo object that contains the user ID and user account of the remote user.

Occurs when the screen sharing information is updated.

Since

v3.6.1

When you call startScreenCaptureByDisplayId or startScreenCaptureByScreenRect to start screen sharing and use the excludeWindowList attribute to block the specified window, the SDK triggers this callback if the window blocking fails.

Note

This callback is for Windows only.

Parameters

info	The screen sharing information. See ScreenCaptureInfo