tencent cloud

TRTCCloudCallback @ TXLiteAVSDK.

Feature

Callback API class for TRTC video call feature.

Common Event Callbacks

onError

Callback for error: SDK encountered an irrecoverable error and must be listened on. Corresponding UI reminders should be displayed based on the actual conditions.

void onError(TXLiteAVError errCode, const char * errMsg, void * extraInfo)

Parameters

onWarning

Callback for warning: this callback is used to alert to some non-serious problems such as lag or recoverable decoding failure.

void onWarning(TXLiteAVWarning warningCode, const char * warningMsg, void * extraInfo)

Parameters

Room Event Callbacks

onEnterRoom

Callback of room entry.

void onEnterRoom(int result)

Parameters

Overview

After the enterRoom() API in TRTCCloud is called to enter a room, the onEnterRoom(result) callback will be received from the SDK.

• If room entry succeeded, result will be a positive number (result > 0), indicating the time in milliseconds (ms) used for entering the room.
• If room entry failed, result will be a negative number (result < 0), indicating the error code for room entry failure. For more information, please see Error Codes.

In TRTC versions below 6.6, the onEnterRoom(result) callback will be returned only for successful room entry, and onError() will be returned for room entry failure. In TRTC v6.6 and above, a positive result will be returned for successful room entry, and a negative result together with the onError() callback will be returned for room entry failure.

onExitRoom

Callback of room exit.

void onExitRoom(int reason)

Parameters

Overview

When the exitRoom() API in TRTCCloud is called, the logic related to room exit will be executed, such as releasing resources of audio/video devices and codecs. After resources are released, the SDK will use the onExitRoom() callback to notify you.
If you need to call enterRoom() again or switch to another audio/video SDK, please wait until you receive the onExitRoom() callback; otherwise, exceptions such as occupied camera or mic may occur.

onSwitchRole

Callback of role switching.

void onSwitchRole(TXLiteAVError errCode, const char * errMsg)

Parameters

Overview

Calling the switchRole() API in TRTCCloud will switch between the anchor and viewer roles, which will be accompanied by a line switch process. After the SDK switches the roles, the onSwitchRole() event callback will be returned.

onConnectOtherRoom

Callback of the result of requesting cross-room call (anchor competition).

void onConnectOtherRoom(const char * userId, TXLiteAVError errCode, const char * errMsg)

Parameters

Overview

Calling the connectOtherRoom() API in TRTCCloud will establish a video call between two anchors in two different rooms, i.e., the "anchor competition" feature. The caller will receive the onConnectOtherRoom() callback to see whether the cross-room call is successful; and if yes, all users in both rooms will receive the onUserVideoAvailable() callback of anchor competition.

onDisconnectOtherRoom

Callback of the result of ending cross-room call (anchor competition).

void onDisconnectOtherRoom(TXLiteAVError errCode, const char * errMsg)

Member Event Callbacks

onRemoteUserEnterRoom

A user enters the current room.

void onRemoteUserEnterRoom(const char * userId)

Parameters

Overview

For the sake of performance, the behaviors of this notification will be different in two different application scenarios:

• Video call scenario (TRTCAppSceneVideoCall): users in this scenario do not have different roles, and this notification will be triggered whenever a user enters the room.
• Online LVB scenario (TRTCAppSceneLIVE): this scenario does not limit the number of viewers. If any user entering or exiting the room could trigger the callback, it would cause great performance loss. Therefore, this notification will be triggered only when an anchor but not a viewer enters the room.

Note: onRemoteUserEnterRoom and onRemoteUserLeaveRoom apply only to maintaining the "member list" of the current room. To display the remote image, it is recommended to listen on the onUserVideoAvailable() event callback.

onRemoteUserLeaveRoom

A user exits the current room, which corresponds to onuserEnterRoom.

void onRemoteUserLeaveRoom(const char * userId, int reason)

Parameters

Overview

Similar to onRemoteUserEnterRoom, the behaviors of this notification will be different in two different application scenarios:

• Video call scenario (TRTCAppSceneVideoCall): users in this scenario do not have different roles, and this notification will be triggered whenever a user exits the room.
• Online LVB scenario (TRTCAppSceneLIVE): this notification will be triggered only when an anchor but not a viewer exits the room.

onUserVideoAvailable

Whether camera is enabled for video.

void onUserVideoAvailable(const char * userId, bool available)

Parameters

Overview

When the onUserVideoAvailable(userId, YES) notification is received, it indicates that available video data frames of the specified image channel have arrived. In this case, the startRemoteView(userId) API needs to be called to load the image of the remote user. Then, the callback of rendering the first video frame, i.e., onFirstVideoFrame(userId), will be received.
When the onUserVideoAvailable(userId, NO) notification is received, it indicates that the specified channel of remote image has been disabled, which may be because the user called muteLocalVideo() or stopLocalPreview().

onUserSubStreamAvailable

Whether screen sharing is enabled.

void onUserSubStreamAvailable(const char * userId, bool available)

Parameters

The function to display the secondary channel image is startRemoteSubStreamView() instead of startRemoteView().

onUserAudioAvailable

Whether audio upstreaming is enabled.

void onUserAudioAvailable(const char * userId, bool available)

Parameters

onFirstVideoFrame

Rendering of the first frame of a local or remote user starts.

void onFirstVideoFrame(const char * userId, const TRTCVideoStreamType streamType, const int width, const int height)

Parameters

Overview

If userId is null, it indicates that the captured local camera image starts to be rendered, which needs to be triggered by calling startLocalPreview first. If userId is not null, it indicates that the first video frame of the remote user starts to be rendered, which needs to be triggered by calling startRemoteView first.

This callback will be triggered only after startLocalPreview(), startRemoteView(), or startRemoteSubStreamView() is called.

onFirstAudioFrame

Playback of the first audio frame of a remote user starts (local audio is not supported for notification currently).

void onFirstAudioFrame(const char * userId)

Parameters

onSendFirstLocalVideoFrame

The first local video frame data has been sent.

void onSendFirstLocalVideoFrame(const TRTCVideoStreamType streamType)

Parameters

Overview

The SDK will start capturing the camera and encode the captured image after successful call of enterRoom() and startLocalPreview(). This callback event will be returned after the SDK successfully sends the first video frame data to the cloud.

onSendFirstLocalAudioFrame

The first local audio frame data has been sent.

void onSendFirstLocalAudioFrame()

Overview

The SDK will start capturing the mic and encoding the captured audio after successful call of enterRoom() and startLocalAudio(). This callback event will be returned after the SDK successfully sends the first audio frame data to the cloud.

onUserEnter

Disused API: an anchor enters the current room.

void onUserEnter(const char * userId)

Parameters

Overview

This callback API can be considered as the disused version of onRemoteUserEnterRoom and is not recommended. Please use onUserVideoAvailable or onRemoteUserEnterRoom for substitution.

This API is disused and not recommended.

onUserExit

Disused API: an anchor exits the current room.

void onUserExit(const char * userId, int reason)

Parameters

Overview

This callback API can be considered as the disused version of onRemoteUserLeaveRoom and is not recommended. Please use onUserVideoAvailable or onRemoteUserEnterRoom for substitution.

This API is disused and not recommended.

Statistics Collection and Quality Callbacks

onNetworkQuality

Network quality: this callback is triggered once every 2 seconds to collect statistics of the current network upstreaming and downstreaming quality.

void onNetworkQuality(TRTCQualityInfo localQuality, TRTCQualityInfo * remoteQuality, uint32_t remoteQualityCount)

Parameters

userId == null indicates the current local video quality.

onStatistics

Callback of technical metric statistics.

void onStatistics(const TRTCStatistics & statis)

Parameters

Overview

If you are familiar with audio/video terms, you can use this callback to get all technical metrics of the SDK. If you are developing an audio/video project for the first time, you can focus only on the onNetworkQuality callback.

The callback is triggered once every 2 seconds.

Server Event Callbacks

onConnectionLost

The connection between SDK and server is closed.

void onConnectionLost()

onTryToReconnect

The SDK tries to connect to the server again.

void onTryToReconnect()

onConnectionRecovery

The connection between SDK and server has been restored.

void onConnectionRecovery()

onSpeedTest

Callback of server speed test. SDK tests the speed of multiple server IPs, and the test result of each IP is returned through this callback notification.

void onSpeedTest(const TRTCSpeedTestResult & currentResult, uint32_t finishedCount, uint32_t totalCount)

Parameters

Hardware Device Event Callbacks

onCameraDidReady

Camera is ready.

void onCameraDidReady()

onMicDidReady

Mic is ready.

void onMicDidReady()

onUserVoiceVolume

Callback of volume level, including the volume level of each userId and total remote volume level.

void onUserVoiceVolume(TRTCVolumeInfo * userVolumes, uint32_t userVolumesCount, uint32_t totalVolume)

Parameters

Overview

The enableAudioVolumeEvaluation API in TRTCCloud can be used to enable this callback or set its triggering interval. It should be noted that after enableAudioVolumeEvaluation is called to enable the volume level callback, no matter whether there is a user speaking in the channel, the callback will be called at the set time interval. If there is no one speaking, userVolumes will be empty, and totalVolume will be 0.

If userId is null, it indicates the volume level of the local user. userVolumes only includes the volume information of users who are speaking (i.e., volume level is not 0).

onDeviceChange

Callback of local device connection and disconnection.

void onDeviceChange(const char * deviceId, TRTCDeviceType type, TRTCDeviceState state)

Parameters

onTestMicVolume

Callback of mic volume level in test.

void onTestMicVolume(uint32_t volume)

Parameters

Overview

The mic test API startMicDeviceTest will trigger this callback.

onTestSpeakerVolume

Callback of speaker volume level in test.

void onTestSpeakerVolume(uint32_t volume)

Parameters

Overview

The speaker test API startSpeakerDeviceTest will trigger this callback.

Custom Message Receipt Callbacks

onRecvCustomCmdMsg

Callback of receipt of a custom message.

void onRecvCustomCmdMsg(const char * userId, int32_t cmdID, uint32_t seq, const uint8_t * message, uint32_t messageSize)

Parameters

Overview

When a user in a room uses sendCustomCmdMsg to send a custom message, other users in the room can receive the message through the onRecvCustomCmdMsg API.

onMissCustomCmdMsg

Callback of loss of a custom message.

void onMissCustomCmdMsg(const char * userId, int32_t cmdID, int32_t errCode, int32_t missed)

Parameters

Overview

TRTC uses the UDP channel; therefore, even if reliable transmission is set, it cannot guarantee that no message will be lost; instead, it can only reduce the message loss rate to a very small value and meet general reliability requirements. After reliable transmission is set on the sender, the SDK will use this callback to notify of the number of custom messages lost during transmission in the specified past time period (usually 5s).

Only when reliable transmission is set on the sender can the receiver receive the callback of message loss.

onRecvSEIMsg

Callback of receipt of an SEI message.

void onRecvSEIMsg(const char * userId, const uint8_t * message, uint32_t messageSize)

Parameters

Overview

When a user in a room uses sendSEIMsg to send data, other users in the room can receive the data through the onRecvSEIMsg API.

CDN Relayed Push Callbacks

onStartPublishCDNStream

Callback of completion of starting relayed push to CDN.

void onStartPublishCDNStream(int errCode, const char * errMsg)

Overview

This callback corresponds to the startPublishCDNStream() API in TRTCCloud.

If Start callback is successful, the relayed push request has been successfully sent to Tencent Cloud. If the target CDN is exceptional, relayed push may fail.

onStopPublishCDNStream

Callback of completion of stopping relayed push to CDN.

void onStopPublishCDNStream(int errCode, const char * errMsg)

Overview

This callback corresponds to the stopPublishCDNStream() API in TRTCCloud.

onSetMixTranscodingConfig

Callback of setting On-Cloud MixTranscoding parameters. This callback corresponds to the setMixTranscodingConfig() API in TRTCCloud.

void onSetMixTranscodingConfig(int errCode, const char * errMsg)

Parameters

Audio Effect Callbacks

onAudioEffectFinished

Callback of ending an audio effect.

void onAudioEffectFinished(int effectId, int code)

Parameters

Screen Sharing Callbacks

onScreenCaptureCovered

This callback will be returned by the SDK when a window for screen sharing is covered and cannot be properly captured. It can be used to ask the user to move the covering window away.

void onScreenCaptureCovered()

onScreenCaptureStarted

This callback will be returned by the SDK when screen sharing is started.

void onScreenCaptureStarted()

onScreenCapturePaused

This callback will be returned by the SDK when screen sharing is paused.

void onScreenCapturePaused(int reason)

Parameters

onScreenCaptureResumed

This callback will be returned by the SDK when screen sharing is resumed.

void onScreenCaptureResumed(int reason)

Parameters

onScreenCaptureStoped

This callback will be returned by the SDK when screen sharing is stopped.

void onScreenCaptureStoped(int reason)

Parameters

Background Audio Mixing Event Callbacks

onPlayBGMBegin

Playback of background music starts.

void onPlayBGMBegin(TXLiteAVError errCode)

Parameters

onPlayBGMProgress

Progress of background music playback.

void onPlayBGMProgress(uint32_t progressMS, uint32_t durationMS)

Parameters

onPlayBGMComplete

Playback of background music ends.

void onPlayBGMComplete(TXLiteAVError errCode)

Parameters

ITRTCVideoRenderCallback

Feature

Callback of custom video rendering.

onRenderVideoFrame

Callback of custom video rendering.

void onRenderVideoFrame(const char * userId, TRTCVideoStreamType streamType, TRTCVideoFrame * frame)

Parameters

Overview

The setLocalVideoRenderCallback and setRemoteVideoRenderCallback APIs can be used to set the custom rendering callback.

ITRTCAudioFrameCallback

Feature

Audio data callback.

onCapturedAudioFrame

Callback of audio data captured by local mic.

void onCapturedAudioFrame(TRTCAudioFrame * frame)

Parameters

• Do not perform any time-consuming operation in this callback function. It is recommended to directly copy the data to another thread for processing; otherwise, various audio exceptions will occur.
• Audio data called back by this API can be modified.
• The frame time length of audio called back by this API is always 0.02s. The formula to convert the frame time length to frame byte length is sample rate * frame time length * number of audio channels * sampling point bit width. For example, the default audio recording format of the SDK has a sample rate of 48,000, mono channel, and sampling point bit width of 16, so its frame byte length will be 48,000 * 0.02s * 1 * 16 bit = 15,360 bit = 1,920 bytes.
• The audio data called back by this API includes pre-processing effects such as background music, audio effects, and audio reverb.

onPlayAudioFrame

Audio data from each remote user before audio mixing (for example, if you want to convert the audio of a channel to text, you need to use the source data instead of the data after audio mixing).

void onPlayAudioFrame(TRTCAudioFrame * frame, const char * userId)

Parameters

• Do not perform any time-consuming operation in this callback function. It is recommended to directly copy the data to another thread for processing; otherwise, various audio exceptions will occur.
• Audio data called back by this API is read only and cannot be modified.

onMixedPlayAudioFrame

Audio data to be played back by speaker after audio data from each channel is mixed.

void onMixedPlayAudioFrame(TRTCAudioFrame * frame)

Parameters

• Do not perform any time-consuming operation in this callback function. It is recommended to directly copy the data to another thread for processing; otherwise, various audio exceptions will occur.
• Audio data called back by this API can be modified.
• The frame time length of audio called back by this API is always 0.02s. The formula to convert the frame time length to frame byte length is sample rate * frame time length * number of audio channels * sampling point bit width. For example, the default audio playback format of the SDK has a sample rate of 48,000, dual channel, and sampling point bit width of 16, so its frame byte length will be 48,000 * 0.02s * 2 * 16 bit = 30,720 bit = 3,840 bytes.
• The audio data called back by this API is the mix of each channel's audio playback data and does not contain the audio data from in-ear monitoring.

ITRTCLogCallback

Feature

Log callback.

onLog

Callback of log printing.

void onLog(const char * log, TRTCLogLevel level, const char * module)

Parameters