Voice Call API

Voice Call API

Java Interface Class Description
Basic Methods (RtcEngine) The RtcEngine class provides the main methods that can be invoked by your application.
Audio Effect Methods (IAudioEffectManager) The IAudioEffectManager class provides the methods to manage the audio effects.
Callback Methods (IRtcEngineEventHandler) The IRtcEngineEventHandler class enables callback event notifications to your application.

Basic Methods (RtcEngine)

Developer suite: io.agora.rtc

The RtcEngine class is the main interface class of the Agora Native SDK. Call the methods of this class to use all the functionalities of the SDK. We recommend calling the RtcEngine API methods in the same thread instead of in multiple threads. In previous versions this class was named AgoraAudio, and it is renamed to RtcEngine from version 1.0.

Developers must follow the corresponding section to implement basic voice first before adding other functions.

Create an RtcEngine Object (create)

public static synchronized RtcEngine create(Context context,
                                             String appId,
                                             IRtcEngineEventHandler handler);

This method creates an RtcEngine object.

Currently, the Agora Native SDK only supports one RtcEngine instance at a time, therefore the application should create only one RtcEngine object. Unless otherwise specified, all called methods provided by the RtcEngine class are executed asynchronously. It is recommended to call the interface methods in the same thread. Unless otherwise specified, the following rule applies to all APIs whose return values are integer types: A return value of 0 indicates that the call was successful, and a return value less than 0 indicates that the call failed.

Name Description
context The context of Android Activity.
appId The App ID issued to the application developers by Agora. Apply for a new one from Agora if the key is missing in your kit.
handler IRtcEngineEventHandler is an abstract class that provides default implementations. The SDK uses this class to report to the application on SDK runtime events.
Return Value An RtcEngine object.

Implementing Voice Communication

This following figure shows how to implement the basic voice communication function. You can add more functions according to the modules described in this document. Ensure that an RtcEngine object has been created for the application according to Create an RtcEngine Object (create).

../_images/android_audio_api.png

Set the Channel Profile (setChannelProfile)

public abstract int setChannelProfile(int profile);

This method configures the channel profile. The Agora RtcEngine needs to know what scenario the application is in to apply different methods for optimization.

The Agora Native SDK supports the following profiles:

Profile Description
Communication Default setting. This is used in one-on-one calls, where all users in the channel can talk freely.
Live Broadcast Live Broadcast. Host and audience roles that can be set by calling setClientRole. The host sends and receives voice, while the audience receives voice only with the sending function disabled.
Gaming Gaming Mode. Any user in the channel can talk freely. This mode uses the codec with low-power consumption and low bitrate by default.

Note

  • Only one profile can be used at the same time in the same channel.
  • This method must be called and configured before a user joining a channel, because the channel profile cannot be configured when the channel is in use.
Name Description
profile

The channel profile. Choose one of the following:

  • CHANNEL_PROFILE_COMMUNICATION: Communication (default)
  • CHANNEL_PROFILE_LIVE_BROADCASTING: Live Broadcast
  • CHANNEL_PROFILE_GAME: Gaming Voice
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Enable the Audio Mode (enableAudio)

public abstract int enableAudio();

This method enables the audio mode, which is enabled by default.

Name Description
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Disable the Audio Mode (disableAudio)

public abstract int disableAudio();

This method disables the audio mode.

Name Description
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Set the Audio Profile (setAudioProfile)

public abstract int setAudioProfile(int profile, int scenario);

This method sets the audio parameters and application scenarios.

Name Description
profile

Sets the sampling rate, bitrate, encode mode, and the number of channels:

  • AUDIO_PROFILE_DEFAULT = 0: default. In the communication mode, the default value is 1; in the live-broadcast mode, the default value is 2
  • AUDIO_PROFILE_SPEECH_STANDARD = 1: Specifies the sampling rate as 32 kHz, audio encoding, single channel, and bitrate up to 18 kbit/s
  • AUDIO_PROFILE_MUSIC_STANDARD = 2: Specifies the sampling rate as 32 kHz, music encoding, single channel, and bitrate up to 48 kbit/s
  • AUDIO_PROFILE_MUSIC_STANDARD_STEREO = 3: Specifies the sampling rate as 32 kHz, music encoding, dual-channel, and bitrate up to 56 kbit/s
  • AUDIO_PROFILE_MUSIC_HIGH_QUALITY = 4: Specifies the sampling rate as 48 kHz, music encoding, single channel, and bitrate up to 128 kbit/s
  • AUDIO_PROFILE_MUSIC_HIGH_QUALITY_STEREO = 5: Specifies the sampling rate as 48 kHz, music encoding, dual-channel, and bitrate up to 192 kbit/s
scenario

Sets the audio application scenarios:

  • AUDIO_SCENARIO_DEFAULT = 0: default
  • AUDIO_SCENARIO_CHARROOM_ENTERTAINMENT = 1: Applicable to the entertainment scenario that supports voice during gameplay
  • AUDIO_SCENARIO_EDUCATION = 2: Applicable to the education scenario that prioritizes fluency and stability
  • AUDIO_SCENARIO_GAME_STREAMING = 3: Applicable to the live gaming scenario that needs to enable the gaming audio effects in the speaker mode in a live broadcast scenario
  • AUDIO_SCENARIO_SHOWROOM = 4: Applicable to the showroom scenario that optimizes the audio quality with professional external equipment
  • AUDIO_SCENARIO_CHATROOM_GAMING = 5: Applicable to the gaming scenario

Note

  • Use this method before joinChannel, else it does not work.
  • In the communication mode, setting profile works, but not scenario.
  • In the communication and live-broadcast mode, the bitrate may be different from your settings due to network self-adaptation.

Join a Channel (joinChannel)

public abstract int joinChannel(String token,
                                String channelName,
                                String optionalInfo,
                                int optionalUid);

This method allows a user to join a channel. Users in the same channel can talk to each other; and multiple users in the same channel can start a group chat. Users using different App IDs cannot call each other. Once in a call, the user must call the leaveChannel method to exit the current call before entering another channel.

Note

A channel does not accept duplicate UIDs, such as two users with the same UID. If your app supports logging in a user from different devices at the same time, ensure that you use different UIDs. For example, if you already used the same UID, make the UIDs different by adding the respective device ID to the UID. This is not applicable if your app does not support a user logging in from different devices at the same time. In this case, when you login a new device, you will be logged out from the other device.

Name Description
token

A Token generated by the application.

This parameter is optional if the user uses a static App ID. In this case, pass NULL as the parameter value.

If the user uses a Token, Agora issues an additional App Certificate to the application developers. The developers can then generate a user key using the algorithm and App Certificate provided by Agora for user authentication on the server.

In most circumstances, the static App ID will suffice. For added security, use a Token.

channelName

A string providing the unique channel name for the AgoraRTC session. The length must be within 64 bytes.

The following is the supported scope: a-z, A-Z, 0-9, space, !

#$%&, ()+,

-, :;<=., >?

@[], ^_, {|}, ~

optionalInfo (Optional) Additional information about the channel. Other users in the channel will not receive this information.
optionalUid

(Optional) User ID: A 32-bit unsigned integer ranging from 1 to (2^32-1). It must be unique. If not assigned (or set to 0), the SDK will assign one and return it in the onJoinChannelSuccess callback. The app needs to record and maintain the returned value as the SDK does not maintain it.

The UID is represented as a 32-bit unsigned integer in the SDK. Since unsigned integers are not supported by Java, the UID is handled as a 32-bit signed integer and larger numbers are interpreted as negative numbers in Java. If necessary, the UID can be converted to a 64-bit integer through “uid&0xffffffffL”.

Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.
  • ERR_INVALID_ARGUMENT (-2): The passed argument is invalid.
  • ERR_NOT_READY (-3): Initialization failed.
  • ERR_REFUSED (-5): The SDK cannot start a call. The SDK could be in another call or failed to create a channel.

Leave a Channel (leaveChannel)

public abstract int leaveChannel();

This method allows a user to leave a channel, such as hanging up or exiting a call.

After joining a channel, the user must call the leaveChannel method to end the call before joining another one. The leaveChannel method releases all resources related to the call. The leaveChannel method is called asynchronously, and the user has not actually left the channel when the call returns. Once the user leaves the channel, the SDK triggers the onLeaveChannel callback.

Note

If you call destroy() immediately after leaveChannel, the leavechannel process will be interrupted, and the SDK will not trigger the onLeaveChannel callback.

Name Description
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Set the Audio Effect

Set the Local Voice Pitch (setLocalVoicePitch)

public abstract int setLocalVoicePitch(double pitch);

This method changes the voice pitch of the local speaker.

Name Description
pitch Voice frequency, in the range of [0.5, 2.0]. The default value is 1.0.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Set the Local Voice Equalization (setLocalVoiceEqualization)

public abstract int setLocalVoiceEqualization(int bandFrequency, int bandGain);

This method sets the local voice equalization effect.

Name Description
bandFrequency The band frequency ranging from 0 to 9; representing the respective 10-band center frequencies of voice effects, including 31, 62, 125, 500, 1k, 2k, 4k, 8k, and 16k Hz.
bandGain Gain of each band in dB; ranging from -15 to 15.

Set the Local Voice Reverberation (setLocalVoiceReverb)

public abstract int setLocalVoiceReverb(int reverbKey, int value);

This method sets the local voice reverberation.

Name Description
reverbKey The reverberation key. This method contains five reverberation keys. For details, see the description of each value:
value
  • AUDIO_REVERB_DRY_LEVEL = 0, (dB, [-20,10]), level of the dry signal
  • AUDIO_REVERB_WET_LEVEL = 1, (dB, [-20,10]), level of the early reflection signal (wet signal)
  • AUDIO_REVERB_ROOM_SIZE = 2, ([0, 100]), room size of the reflection
  • AUDIO_REVERB_WET_DELAY = 3, (ms, [0, 200]), length of the initial latency of the wet signal in ms
  • AUDIO_REVERB_STRENGTH = 4, ([0, 100]), length of the late reverberation

Set the Audio Route

Set the Default Audio Route (setDefaultAudioRouteToSpeakerphone)

public abstract int setDefaultAudioRoutetoSpeakerphone(boolean defaultToSpeaker);

This method modifies the default audio route if necessary.

Note

This method only works in audio mode.

The default audio routes are listed in the following table:

Channel Mode Default Audio Route
Communication Earpiece
Live Broadcast Speakerphone
Game Voice Speakerphone

Modify the default audio route if necessary according to the following table:

Name Description
defaultToSpeaker
  • True: Speakerphone.
  • False: Earpiece.

No matter whether the audio is routed to the speakerphone or earpiece, once a headset is plugged in or Bluetooth is connected,

the audio route will be changed. The audio route will be switched to default once removing the headset or disconnecting Bluetooth.

Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Enable the Speakerphone (setEnableSpeakerphone)

public abstract int setEnableSpeakerphone(boolean enabled);

This method enables the audio routing to the speakerphone.

After calling this method, the SDK will return the onAudioRouteChanged callback to indicate the changes.

Note

Ensure that you have read the default audio route explanation according to Set the Default Audio Route (setDefaultAudioRouteToSpeakerphone) and checked whether it is necessary to call this method.

Name Description
enabled
  • True:
    • If this API is called after joining a channel, whether the audio was routed to the headset, Bluetooth device, or earpiece, it will be routed to the speaker.
    • If this API is called before joining a channel, when joining a channel, the audio will be routed to the speaker whether the user uses a headset or Bluetooth device.
  • False: The audio will follow the default audio route mentioned in Set the Default Audio Route (setDefaultAudioRouteToSpeakerphone).
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Check Whether the Speakerphone is Enabled (isSpeakerphoneEnabled)

public abstract boolean isSpeakerphoneEnabled();

This method checks whether the speakerphone is enabled or disabled.

Name Description
Return value
  • true: The speakerphone is enabled.
  • false: The speakerphone is not enabled.

Enable In-ear Monitoring (enableInEarMonitoring)

public abstract int enableInEarMonitoring(boolean enabled);

This method enables or disables the in-ear monitoring function.

Name Description
enabled
  • true: Enalbe in-ear monitoring.
  • false: Disable in-ear monitoring.
Return Value
  • 0: Method call succeeded.
  • < 0: Method call failed.

Set the Audio Volume

Set the Speakerphone Volume (setSpeakerphoneVolume)

public abstract int setSpeakerphoneVolume(int volume);

This method sets the speakerphone volume.

Name Description
volume Sets the speakerphone volume between 0 (lowest) to 255 (highest).
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Enable the Audio Volume Indication (enableAudioVolumeIndication)

public abstract int enableAudioVolumeIndication(int interval, int smooth)

This method allows the SDK to regularly report to the application on which user is speaking and the volume of the speaker.

Name Description
interval

Time interval between two consecutive volume indications:

  • <= 0: Disables the volume indication.
  • > 0: The time interval between two consecutive volume indications in milliseconds. Agora recommends setting it to a minimum of 200 ms. Once the method is enabled, the SDK returns the volume indication at the set time interval in the Audio Volume Indication Callback (onAudioVolumeIndication) callback, regardless of whether anyone is speaking in the channel.
smooth Smoothing factor. The default value is 3.
Return values
  • 0: Method call succeeded.
  • < 0: Method call failed.

Set the Volume of the In-ear Monitor (setInEarMonitoringVolume)

public abstract int setInEarMonitoringVolume(int volume);

This method sets the volume of the in-ear monitor.

Name Description  
volume Volume of the in-ear monitor ranging from 0 to 100. The default value is 100.

Configure the External Audio Source

Set the External Audio Source (setExternalAudioSource)

public abstract int setExternalAudioSource(boolean enabled, int sampleRate, int channels);

This method sets the external audio source.

Name Description
enabled Enable external audio source: True/False
sampleRate Sampling rate of the external audio source
channelsPerFrame Number of external audio source channels (two channels maximum)

Push the External Audio Frame (pushExternalAudioFrameRawData)

public abstract int pushExternalAudioFrame(byte[] data, long timestamp);

This method pushes the external audio frame to the Agora SDK for encoding.

Name Description
data External audio data
timestamp Timestamp of the external audio frame to be synchronized with the external video source

Mute the Audio Stream

Mute the Local Audio Stream (muteLocalAudioStream)

public abstract int muteLocalAudioStream(boolean muted);

This method enables/disables sending local audio streams to the network.

Note

When set to True, this method does not disable the microphone, and does not affect any ongoing recording.

Name Description
On
  • True: Stops sending local audio streams to the network.
  • False: Allows sending local audio streams to the network.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Mute all Remote Audio Streams (muteAllRemoteAudioStreams)

public abstract int muteAllRemoteVideoStreams(boolean muted);

This method mutes/unmutes all remote users’ audio streams.

Note

When set to True, this method mutes audio streams without affecting the audio stream receiving process.

Name Description
muted
  • True: Mutes all received audio streams.
  • False: Unmutes all received audio streams.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Mute a Remote Audio Stream (muteRemoteAudioStream)

public abstract int muteRemoteAudioStream(int uid, boolean muted);

This method mutes/unmutes a specified user’s audio stream.

Note

When set to True, this method mutes the audio stream without affecting the audio stream receiving process.

Name Description
uid User ID of the user whose audio stream is to be muted.
mute
  • True: Mutes the user’s audio stream.
  • False: Unmutes the user’s audio stream.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Audio Mixing

Start Audio Mixing (startAudioMixing)

public abstract int startAudioMixing(String filePath,
                                     boolean loopback,
                                     boolean replace,
                                     int cycle);

This method mixes the specified local audio file with the audio stream from the microphone; or, it replaces the microphone’s audio stream with the specified local audio file. You can choose whether the other user can hear the local audio playback and specify the number of loop playbacks. This API also supports online music playback.

Note

  • To use this API, ensure that the Android device version is 4.2 or later, and the API version is 16 or later.
  • Call this API when you are in the channel, otherwise it may cause issues.
  • If you call this API on an emulator, only the MP3 file format is supported.
Name Description
filePath

Name and path of the local audio file to be mixed:

  • If the path begins with /assets/, find the audio file in the /assets/ directory.
  • Otherwise, find the audio file in the absolute path.

Supported audio formats: mp3, aac, m4a, 3gp, wav, flac

loopback
  • True: Only the local user can hear the remix or the replaced audio stream.
  • False: Both users can hear the remix or the replaced audio stream.
replace
  • True: The content of the local audio file replaces the audio stream from the microphone.
  • False: Local audio file mixed with the audio stream from the microphone.
cycle

Number of loop playbacks:

  • Positive integer: Number of loop playbacks
  • -1: Infinite loop
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Stop Audio Mixing (stopAudioMixing)

public abstract int stopAudioMixing();

This method stops audio mixing. Call this API when you are in a channel.

Name Description
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Pause Audio Mixing (pauseAudioMixing)

public abstract int pauseAudioMixing();

This method pauses audio mixing. Call this API when you are in a channel.

Name Description
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Resume Audio Mixing (resumeAudioMixing)

public abstract int resumeAudioMixing();

This method resumes audio mixing. Call this API when you are in a channel.

Name Description
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Adjust the Audio Mixing Volume (adjustAudioMixingVolume)

public abstract int adjustAudioMixingVolume(int volume);

This method adjusts the volume during audio mixing. Call this API when you are in a channel.

Name Description
volume Volume ranging from 0 to 100. By default, 100 is the original volume.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Get the Audio Mixing Duration (getAudioMixingDuration)

public abstract int getAudioMixingDuration();

This method gets the duration (ms) of audio mixing. Call this API when you are in a channel. A return value of 0 means that this method call has failed.

Get the Current Audio Position (getAudioMixingCurrentPosition)

public abstract int getAudioMixingCurrentPosition();

This method gets the playback position (ms) of the audio. Call this API when you are in a channel.

Drag the Audio Progress Bar (setAudioMixingPosition)

public abstract int setAudioMixingPosition(int pos);

This method drags the playback progress bar of the audio mixing file to where you want to play instead of playing it from the beginning.

Name Description
pos Integer. The position of the audio mixing file (ms).

Recording

Start an Audio Recording (startAudioRecording)

public abstract int startAudioRecording(String filePath, int quality);

This method starts an audio recording. The SDK allows recording during a call, which supports either one of the following two formats:

  • .wav: Large file size with high sound fidelity OR
  • .aac: Small file size with low sound fidelity

Ensure that the directory to save the recording file exists and is writable. This method is usually called after the joinChannel() method. The recording automatically stops when the leaveChannel() method is called.

Name Description
filePath Full file path of the recording file. The string of the file name is in UTF-8 code.
quality

Audio recording quality:

  • AUDIO_RECORDING_QUALITY_LOW = 0: Low quality, file size around 1.2 MB after 10 minutes of recording.
  • AUDIO_RECORDING_QUALITY_MEDIUM = 1: Medium quality, file size around 2B M after 10 minutes of recording.
  • AUDIO_RECORDING_QUALITY_HIGH = 2: High quality, file size around 3.75 MB after 10 minutes of recording.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Stop an Audio Recording (stopAudioRecording)

public abstract int stopAudioRecording();

This method stops recording on the client.

Note

Call this method before calling leaveChannel, otherwise the recording automatically stops when the leaveChannel method is called.

Name Description
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Adjust the Recording Volume (adjustRecordingSignalVolume)

public abstract int adjustRecordingSignalVolume(int volume);

This method adjusts the recording volume.

Name Description
volume

Recording volume, ranges from 0 to 400:

  • 0: Mute.
  • 100: Original volume.
  • 400: (Maximum) Four times the original volume with signal clipping protection
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Adjust the Playback Volume (adjustPlaybackSignalVolume)

public abstract int adjustPlaybackSignalVolume(int volume);

This method adjusts the playback volume.

Name Description
volume

Playback volume, ranges from 0 to 400:

  • 0: Mute.
  • 100: Original volume.
  • 400: (Maximum) Four times the original volume with signal clipping protection
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Encryption

Register a Packet Observer (registerAgoraPacketObserver)

JNIEXPORT jint registerAgoraPacketObserver(void* engine,agora::rtc::IPacketObserver* observer);

This method registers a packet observer. When sending or receiving audio packets, the Agora SDK calls back the interface defined by IPacketObserver, and the application can use this interface to process data by performing data encryption and decryption. When the application initializes the RtcEngine instance, use dlopen/dlsym to find registerAgoraPacketObserver, which is the derived function of libagora-rtc-sdk-jni.so.

Note

The maximum size of the processed network packet is 1200 bytes. A packet larger than the maximum size may not be sent successfully.

Name Description
engine It can be retrieved by calling the API RtcEngine.getNativeHandle().
observer Callback interface of the send/receive packet.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Enable Built-in Encryption (setEncryptionSecret)

public abstract int setEncryptionSecret(String secret);

Use setEncryptionSecret to specify an encryption password to enable built-in encryption before joining a channel. All users in a channel must set the same encryption password. The encryption password is automatically cleared once a user has left the channel. If the encryption password is not specified or set to empty, the encryption function will be disabled.

Name Description
secret Encryption Password
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Set the Built-in Encryption Mode (setEncryptionMode)

public abstract int setEncryptionMode(String encryptionMode);

The Agora Native SDK supports built-in encryption, which is in AES-128-XTS mode by default. If you want to use other modes, call this API to set the encryption mode.

All users in the same channel must use the same encryption mode and password. Refer to information related to the AES encryption algorithm on the differences between encryption modes.

Note

Call setEncryptionSecret to enable the built-in encryption function before calling this API.

Name Description
encryptionMode

Encryption mode. The following modes are currently supported:

  • “aes-128-xts”:128-bit AES encryption, XTS mode
  • “aes-128-ecb”:128-bit AES encryption, ECB mode
  • “aes-256-xts”: 256-bit AES encryption, XTS mode
  • “”: When it is set to a NULL string, the encryption is in “aes-128-xts” by default.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Establish a Data Channel

Create a Data Stream (createDataStream)

public abstract int createDataStream(boolean reliable, boolean ordered);

This method creates a data stream. Each user can only have up to five data channels at the same time.

Note

Set reliable and ordered both as True or both as False. Do not set one as True and the other as False.

Name Description
reliable
  • True: The recipients will receive data from the sender within 5 seconds. If the recipient does not receive the sent data within 5 seconds, the data channel will report an error to the application.
  • False: The recipients will not receive any data, and it will not report any error upon data missing.
ordered
  • True: The recipients will receive data in the order of the sender.
  • False: The recipients will not receive data in the order of the sender.
Return Value
  • <0: Returns an error code when it fails to create the data stream. [1]
  • >0: Returns the Stream ID when the data stream is created.

Footnotes

[1]The error code is related to the positive integer displayed in Error Codes and Warning Codes, for example, if it returns -2, then it indicates 2: ERR_INVALID_ARGUMENT in Error Codes and Warning Codes.

Send a Data Stream (sendStreamMessage)

public abstract int sendStreamMessage(int streamId, byte[] message);

This method sends data stream messages to all users in a channel. Up to 30 packets can be sent per second in a channel with each packet having a maximum size of 1 kB. The API controls the data channel transfer rate. Each client can send up to 6 kB of data per second. Each user can have up to five data channels simultaneously.

Name Description
streamId Stream ID returned by createDataStream.
message Data to be sent
Return Value

When it fails to send the message, the following error code will be returned:

ERR_SIZE_TOO_LARGE/ERR_TOO_OFTEN/ERR_BITRATE_LIMIT

Test and Detection

Start an Audio Call Test (startEchoTest)

public abstract int startEchoTest();

This method launches an audio call test to determine whether the audio devices (for example, headset and speaker) and the network connection are working properly. In the test, the user first speaks, and the recording is played back in 10 seconds. If the user can hear the recording in 10 seconds, it indicates that the audio devices and network connection work properly.

Note

After calling the startEchoTest method, call stopEchoTest to end the test; otherwise the application cannot run the next echo test, nor can it call the joinChannel method to start a new call.

Name Description
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.
  • ERR_REFUSED (-5): Failed to launch the echo test, for example, initialization failed.

Stop an Audio Call Test (stopEchoTest)

public abstract int stopEchoTest();

This method stops the audio call test.

Name Description
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.
  • ERR_REFUSED(-5): Failed to stop the echo test. It could be that the echo test is not running.

Enable the Network Test (enableLastmileTest)

public abstract int enableLastmileTest();

This method tests the quality of the user’s network connection and is disabled by default.

Before users join a channel, they can call this method to check the network quality.

Calling this method consumes extra network traffic, which may affect the communication quality. Call disableLastmileTest to disable it immediately once users have received the onLastmileQuality callback before they join the channel.

Name Description
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Disable the Network Test (disableLastmileTest)

public abstract int disableLastmileTest();

This method disables the network connection quality test.

Name Description
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Monitor the Network Connection Event (monitorConnectionEvent)

public abstract void monitorConnectionEvent(boolean monitor);

This method monitors the network connection event, which is enabled by default. The application calls this method before entering the channel.

Name Description
monitor
  • True: Monitoring network connection event enabled. (Default)
  • False: Monitoring network connection event disabled.

Feedback

Get the Current Call ID (getCallId)

public abstract String getCallId();

This method gets the current call ID.

When a user joins a channel on a client, a CallId is generated to identify the call from the client. Some methods such as rate and complain need to be called after the call ends in order to submit feedback to the SDK. These methods require assigned values of the CallId parameters. To use these feedback methods, call the getCallId method to retrieve the CallId during the call, and then pass the value as an argument in the feedback methods after the call ends.

Name Description
Return Value Current call ID.

Rate the Call (rate)

public abstract int rate(String callId,
                         int rating,
                         String description);

This method lets the user rate the call. It is usually called after the call ends.

Name Description
callId Call ID retrieved from the getCallId method.
rating Rating for the call between 1 (lowest) to 10 (highest).
description

Description for the call with a length less than 800 bytes.

This parameter is optional.

Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.
  • ERR_INVALID_ARGUMENT (-2): The passed argument is invalid, for example, callId invalid.
  • ERR_NOT_READY (-3): The SDK status is incorrect, for example, initialization failed.

Complain about the Call Quality (complain)

public abstract int complain(String callId,
                             String description);

This method allows the user to complain about the call quality. It is usually called after the call ends.

Name Description
callId Call ID retrieved from the getCallId method.
description

A given description for the call with a length less than 800 bytes.

This parameter is optional.

Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.
  • ERR_INVALID_ARGUMENT (-2): The passed argument is invalid, for example, callId invalid.
  • ERR_NOT_READY (-3): The SDK status is incorrect, for example, initialization failed.

Others

Renew the Token (renewToken)

public abstract int renewToken(String token);

This method updates the Token.

The key expires after a certain period of time once the Token schema is enabled. When the onError callback reports the error ERR_TOKEN_EXPIRED(109), the application should retrieve a new key and then call this method to renew it. Failure to do so will result in the SDK disconnecting with the server.

Name Description
token Specifies the Token to be renewed.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Specify a Log File (setLogFile)

public abstract int setLogFile(String filePath);

This method specifies an SDK output log file. The log file records all the log data of the SDK’s operation. Ensure that the directory to save the log file exists and is writable.

Name Description
filePath File path of the log file. The string of the log file is in UTF-8 code.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Set the Log Filter (setLogFilter)

public abstract int setLogFilter(int filter);

This method sets the SDK output log filter. You can use either one or a combination of the filters.

Name Description
filter

Set the levels of the filters:

  • LOG_FILTER_OFF = 0;
  • LOG_FILTER_CRITICAL = 0x0008;
  • LOG_FILTER_ERROR = 0x000c;
  • LOG_FILTER_WARN = 0x000e;
  • LOG_FILTER_INFO = 0x000f;
  • LOG_FILTER_CRITICAL = 0x080f;
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Destroy the Engine Instance (destroy)

public static synchronized void destroy();

This method releases all the resources used by the Agora SDK. This is useful for applications that occasionally make voice calls, to free up resources for other operations when not making calls. Once the application calls destroy() to destroy the created RtcEngine instance, no other methods in the SDK can be used and no callbacks can occur.

To start communication again, reinitialize sharedEngineWithappId to create a new instance of AgoraRtcEngineKit.

Note

This method is called synchronously. The result returns after the IRtcEngine object resources are released. The app should not call this interface in the callback generated by the SDK, otherwise the SDK must wait for the callback to return before it can reclaim the related object resources, causing a deadlock.

Name Description
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Get the SDK Version (getSdkVersion)

public static String getSdkVersion();

This method returns the string of the version number in character format.

Audio Effect Methods (IAudioEffectManager)

Get the Audio Effect Volume (getEffectsVolume)

public double getEffectsVolume();

This method gets the volume of the audio effects from 0.0 to 1.0.

Set the Audio Effect Volume (setEffectsVolume)

public int setEffectsVolume(double volume);

This method sets the volume of the audio effects.

Name Description
volume The value ranges from 0.0 to 100.0. 100.0 is the default value.
Return Value
  • 0: Method call succeeded
  • <0: Method call failed

Adjust the Audio Effect Volume in Real Time (setVolumeOfEffect)

public int setVolumeOfEffect(int soundId, double volume);

This method adjusts the volume of the specified sound effect in real time.

Name Description
soundId ID of the audio effect. Each audio effect has a unique ID.
volume The value ranges from 0.0 to 100.0. 100.0 is the default value.
Return Value
  • 0: Method call succeeded
  • <0: Method call failed

Play the Audio Effect (playEffect)

Note

This function is now in BETA and will be officially released within two weeks.

public int playEffect(int soundId, String filePath, int loopCount, double pitch, double pan, double gain, boolean publish);

This method plays the specified audio effect.

Name Description
soundId ID of the specified audio effect. Each audio effect has a unique ID [2].
filePath The absolute file path of the audio effect file.
loopCount

Set the number of times looping the audio effect:

  • 0: Play the audio effect once
  • 1: Play the audio effect twice
  • -1: Play the audio effect in a loop indefinitely, until stopEffect or stopAllEffects is called
pitch Set whether to change the pitch of the audio effect. The range is [0.5, 2]. The default value is 1, which means no change to the pitch. The smaller the value, the lower the pitch.
pan

Spatial position of the audio effect. The range is [-1, 1]

  • 0: The audio effect shows ahead.
  • 1: The audio effect shows on the right.
  • -1: The audio effect shows on the left.
gain Volume of the audio effect. The range is [0.0, 100,0]. The default value is 100.0. The smaller the value, the lower the volume of the audio effect.
publish

Set whether to publish the specified audio effect to the remote stream:

  • true: The audio effect, played locally, is published to the Agora Cloud and the remote users can hear it.
  • false: The audio effect, played locally, is not published to the Agora Cloud and the remote users cannot hear it.
Return Value
  • 0: Method call succeeded.
  • < 0: Method call failed.

Footnotes

[2]If you preloaded the audio effect into the memory through preloadEffect, ensure that the soundID value is set to the same value as in preloadEffect.

Note

In version v2.1.0, the following method, which is not recommended by Agora, is used.

public int playEffect(int soundId, String filePath, boolean loop, double pitch, double pan, double gain);

Stop Playing an Audio Effect (stopEffect)

public int stopEffect(int soundId);

This method stops playing a specific audio effect.

Name Description
soundId ID of the audio effect. Each audio effect has a unique ID.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Stop Playing all Audio Effects (stopAllEffects)

public int stopAllEffects();

This method stops playing all audio effects.

Preload an Audio Effect (preloadEffect)

public int preloadEffect(int soundId, String filePath);

This method preloads a specific audio effect file (compressed audio file) in the memory.

Name Description
soundId ID of the audio effect. Each audio effect has a unique ID.
filePath Absolute path of the audio effect file.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Release an Audio Effect (unloadEffect)

public int unloadEffect(int soundId);

This method releases a specific preloaded audio effect from the memory.

Name Description
soundId ID of the audio effect. Each audio effect has a unique ID.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Pause an Audio Effect (pauseEffect)

public int pauseEffect(int soundId);

This method pauses a specific audio effect.

Name Description
soundId ID of the audio effect. Each audio effect has a unique ID.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Pause all Audio Effects (pauseAllEffects)

public int pauseAllEffects();

This method pauses all audio effects.

Name Description
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Resume an Audio Effect (resumeEffect)

public int resumeEffect(int soundId);

This method resumes playing a specific audio effect.

Name Description
soundId ID of the audio effect. Each audio effect has a unique ID.
Return Value
  • 0: Method call succeeded.
  • <0: Method call failed.

Resume all Audio Effects (resumeAllEffects)

public int resumeAllEffects();

This method resumes all audio effects.

Callback Methods (IRtcEngineEventHandler)

Developer Suite: io.agora.rtc

The IRtcEngineEventHandler interface class is used to send callback event notifications to the application. The application inherits the interface class methods to get the event notifications.

All methods in this interface class have a default (empty) implementation, and the application can inherit only required events. In the callback method, the application should avoid time-consuming tasks or calling blocking APIs (such as SendMessage), otherwise the SDK may not work properly.

Join a Channel Callback (onJoinChannelSuccess)

public void onJoinChannelSuccess( String channel,
                                    int uid,
                                    int elapsed );

This callback indicates that the user has successfully joined the specified channel with an assigned channel ID and user ID. The channel ID is assigned based on the channel name specified in the join() API. If the user ID is not specified when join() is called, the server assigns one automatically.

Name Description
channel Channel name.
uid

User ID.

If the uid is specified in the joinChannel method, it returns the specified ID; if not, it returns an ID that is automatically assigned by the Agora server.

elapsed Time elapsed (ms) from calling joinChannel until this event occurs.

Rejoin a Channel Callback (onRejoinChannelSuccess)

public void onRejoinChannelSuccess(   String channel,
                                      int uid,
                                      int elapsed );

When the client loses connection with the server because of network problems, the SDK automatically attempts to reconnect, and triggers this callback method upon reconnection.

Name Description
channel Channel name.
uid User ID.
elapsed Time elapsed (ms) from calling joinChannel until this event occurs.

Warning Occurred Callback (onWarning)

public void onWarning(int warn);

This callback indicates that some warning occurred during the SDK runtime. In most cases, the application can ignore the warnings reported by the SDK because the SDK can usually fix the issue and resume running. For instance, the SDK may report an ERR_OPEN_CHANNEL_TIMEOUT warning upon disconnection with the server and attempts to reconnect.

Name Description
warn The Warning Code. For details, see Error Codes and Warning Codes

Error Occurred Callback (onError)

public void onError(int err);

This callback indicates that a network or media error occurred during the SDK runtime.

In most cases, reporting an error means that the SDK cannot fix the issue and resume running, and therefore requires actions from the application or simply informs the user about the issue. For instance, the SDK reports an ERR_START_CALL error when it fails to initialize a call. In this case, the application informs the user that the call initialization has failed, and calls the leaveChannel method to exit the channel.

Name Description
err

Error codes:

  • ERR_INVALID_VENDOR_KEY(101): Invalid App ID.
  • ERR_INVALID_CHANNEL_NAME(102): Invalid channel name.
  • ERR_LOOKUP_CHANNEL_REJECTED(105): Failed to look up the channel because the server rejected the request.
  • ERR_OPEN_CHANNEL_REJECTED(107): Failed to join the channel because the media server rejected the request.
  • ERR_LOAD_MEDIA_ENGINE(1001): Failed to load the media engine.
  • ERR_START_CALL(1002): Failed to open the local audio devices and thus failed to start a call.
  • ERR_START_CAMERA(1003): Failed to start the local camera.

Leave a Channel Callback (onLeaveChannel)

public void onLeaveChannel(RtcStats stats);

When the application calls the leaveChannel() method, the SDK uses this callback to notify the application that the user has successfully left the channel. With this callback function, the application retrieves information such as the call duration and the statistics of data received/transmitted by the Audio Quality Callback SDK (onAudioQuality).

Definition of RtcStats

public static class RtcStats {
    public int totalDuration; // in seconds
    public int txBytes;
    public int rxBytes;
    public int txKBitRate;
    public int rxKBitRate;
    public int txAudioKBitRate;
    public int rxAudioKBitRate;
    public int txVideoKBitRate;
    public int rxVideoKBitRate;
    public int users;
    public double cpuTotalUsage;
    public double cpuAppUsage;
}
Name Description
stats

Statistics of the call:

  • totalDuration: Call duration in seconds, represented by an aggregate value.
  • txBytes: Total number of bytes transmitted, represented by an aggregate value.
  • rxBytes: Total number of bytes received, represented by an aggregate value.
  • txKBitRate: Transmission bitrate in kbit/s, represented by an instantaneous value.
  • rxKBitRate: Receive bitrate in kbit/s, represented by an instantaneous value.
  • txAudioKBitrate: Audio transmission bitrate in kbit/s, represented by an instantaneous value.
  • rxAudioKBitRate: Audio receive bitrate in kbit/s, represented by an instantaneous value.
  • txVideoKBitRate: Video transmission bitrate in kbit/s, represented by an instantaneous value.
  • rxVideoKBitRate: Video receive bitrate in kbit/s, represented by an instantaneous value.
  • users: The number of users in the channel.
  • puTotalUsage: System CPU usage (%).
  • cpuAppUsage: Application CPU usage (%).

Audio Route Changed Callback (onAudioRouteChanged)

public void onAudioRouteChanged(int routing);

The SDK notifies the application that the audio route has changed after calling setEnableSpeakerphone successfully.

It notifies the current audio route is switched to earpiece, speakerphone, headset or bluetooth. The definition of routing is listed as follows:

public static final int AUDIO_ROUTE_DEFAULT = -1;
public static final int AUDIO_ROUTE_HEADSET = 0;
public static final int AUDIO_ROUTE_EARPIECE = 1;
public static final int AUDIO_ROUTE_HEADSETNOMIC = 2;
public static final int AUDIO_ROUTE_SPEAKERPHONE = 3;
public static final int AUDIO_ROUTE_LOUDSPEAKER = 4;
public static final int AUDIO_ROUTE_HEADSETBLUETOOTH = 5;

Audio Quality Callback (onAudioQuality)

public void onAudioQuality(int uid,
                           int quality,
                           short delay,
                           short lost);

During a call, this callback is triggered once every two seconds to report the audio quality of the current call. By default it is enabled.

Name Description
uid User ID of the speaker
quality

Rating of the audio quality:

  • QUALITY_UNKNOWN(0): The network quality is unknown.
  • QUALITY_EXCELLENT(1): The network quality is excellent.
  • QUALITY_GOOD(2): The network quality is quite good, but the bitrate may be slightly lower than excellent.
  • QUALITY_POOR(3): Users can feel the communication slightly impaired.
  • QUALITY_BAD(4): Users can communicate only not very smoothly.
  • QUALITY_VBAD(5): The network is so bad that users can hardly communicate.
  • QUALITY_DOWN(6): Users cannot communicate at all.
delay Time delay in milliseconds.
lost The packet loss rate(%).

Audio Volume Indication Callback (onAudioVolumeIndication)

public void onAudioVolumeIndication(AudioVolumeInfo[] speakers, unsigned int speakerNumber, int totalVolume);

This callback indicates who is talking and the speaker’s volume.

The indication is disabled by default. If needed, use the enableAudioVolumeIndication() method to configure it.

Name Description
speakers

The speakers (array). Each speaker ():

  • uid: User ID of the speaker.
  • volume: The volume of the speaker between 0 (lowest volume) to 255 (highest volume).
speakerNumber Total number of speakers.
totalVolume Total volume after audio mixing between 0 (lowest volume) to 255 (highest volume).

Other User Joined Channel Callback (onUserJoined)

public void onUserJoined(int uid, int elapsed);

This callback method notifies the application that another user has joined the channel. If there are other users in the channel when that user joins, the SDK also reports to the application who the existing users are in the channel.

Name Description
uid User ID.
elapsed Time delay (ms) from calling joinChannel until this callback is triggered.

Other User Offline Callback (onUserOffline)

public void onUserOffline(int uid, int reason);

This callback notifies the application that a user has left the channel or is offline.

The SDK reads the timeout data to determine if a user has left the channel (or has gone offline). If no data package is received from the user in 15 seconds, the SDK assumes the user is offline. A poor network connection may lead to false detections; therefore, use signaling for reliable offline detection.

Name Description
uid User ID.
reason This callback is triggered when:
  • USER_OFFLINE_QUIT(0): A user has quit the call.
  • USER_OFFLINE_DROPPED(1): The SDK timed out and the user dropped offline because it did not receive any data package for a period of time.

When a user quits the call but the message is not passed to the SDK due to an unreliable channel, the SDK may assume that the user has timed out and dropped offline.

Other User Muted Audio Callback (onUserMuteAudio)

public void onUserMuteAudio(int uid, boolean muted);

This callback indicates that some other user has muted/unmuted his/her audio stream.

Note

Currently, this callback is invalid when the number of users in a channel exceeds 20.

Name Description
uid User ID.
muted
  • True: User has muted his/her audio.
  • False: User has unmuted his/her audio.

RTC:engine Statistics Callback (onRtcStats)

public void onRtcStats(RtcStats stats);

The SDK updates the application on the statistics of the RTC:engine runtime status once every two seconds.

Name Description
stats The state of the Rtc Engine. For details, see the definition of Rtcstats in Leave a Channel Callback (onLeaveChannel)

Network Quality Callback (onLastmileQuality)

public void onLastmileQuality(int quality);

This callback reports the network quality of the local user. It is triggered once every two seconds after calling enableLastmileTest().

Name Description
quality

Quality of the last mile network:

  • QUALITY_UNKNOWN(0): The network quality is unknown.
  • QUALITY_EXCELLENT(1): The network quality is excellent.
  • QUALITY_GOOD(2): The network quality is quite good, but the bitrate may be slightly lower than excellent.
  • QUALITY_POOR(3): Users can feel the communication slightly impaired.
  • QUALITY_BAD(4): Users can communicate only not very smoothly.
  • QUALITY_VBAD(5): The network is so bad that users can hardly communicate.
  • QUALITY_DOWN(6): Users cannot communicate at all.

Channel Network Quality Callback (onNetworkQuality)

public void onNetworkQuality(uid_t uid, int txQuality, int rxQuality);

This callback is triggered regularly to update the application on the network quality in a communication or live broadcast channel.

Name Description
uid User ID. The network quality of the user with this UID will be reported. If uid is 0, it reports the local network quality. The current release only reports the quality of the local user.
txQuality

The transmission quality of the user:

  • QUALITY_UNKNOWN(0): The network quality is unknown.
  • QUALITY_EXCELLENT(1): The network quality is excellent.
  • QUALITY_GOOD(2): The network quality is quite good, but the bitrate may be slightly lower than excellent.
  • QUALITY_POOR(3): Users can feel the communication slightly impaired.
  • QUALITY_BAD(4): Users can communicate only not very smoothly.
  • QUALITY_VBAD(5): The network is so bad that users can hardly communicate.
  • QUALITY_DOWN(6): Users cannot communicate at all.
rxQuality

The receiving quality of the user:

  • QUALITY_UNKNOWN(0): The network quality is unknown.
  • QUALITY_EXCELLENT(1): The network quality is excellent.
  • QUALITY_GOOD(2): The network quality is quite good, but the bitrate may be slightly lower than excellent.
  • QUALITY_POOR(3): Users can feel the communication slightly impaired.
  • QUALITY_BAD(4): Users can communicate only not very smoothly.
  • QUALITY_VBAD(5): The network is so bad that users can hardly communicate.
  • QUALITY_DOWN(6): Users cannot communicate at all.

Remote Video State Changed Callback (onRemoteVideoStateChanged)

Note

This function is now in BETA and will be officially released within two weeks.

public void onRemoteVideoStateChanged(int uid, int state);

This callback indicates that the state of the remote video has changed.

Name Description
uid ID of the user whose video state has changed
state

The state of the remote video:

  • 1: The remote video is normal
  • 2: The remote video is frozen

Connection Interrupted Callback (onConnectionInterrupted)

public void onConnectionInterrupted();

This method indicates that the SDK has lost connection with the server.

This method is triggered upon connection lost, while the onConnectionLost method is triggered when the SDK attempts to reconnect after losing connection. Once the connection is lost, and if the application does not call leaveChannel, the SDK automatically tries to reconnect repeatedly.

Connection Lost Callback (onConnectionLost)

public void onConnectionLost();

This callback indicates that the SDK has lost connection with the network, and it has remained unconnected for a period of time (10 seconds by default) despite that it attempts to reconnect. The SDK will keep trying to reconnect after this callback is triggered. Upon reconnection, an onRejoinChannelSuccess callback will then be triggered.

Connection Banned Callback (onConnectionBanned)

public void onConnectionBanned();

This callback is triggered when your connection is banned by the Agora Server.

Data Stream Received Callback (onStreamMessage)

public void onStreamMessage(int uid, int streamId, byte[] data);

This callback indicates that the local user has received the data stream from the other user within five seconds.

Name Description
uid User ID
streamId Stream ID
data The data received by the recipients.

Data Stream Sent Failure Callback (onStreamMessageError)

public void onStreamMessageError(int uid, int streamId, int error, int missed, int cached);

This callback indicates that the local user has not received the data stream from the other user within five seconds.

Name Description
uid User ID
streamId Stream ID
code
  • ERR_OK = 0, No error
  • ERR_NOT_IN_CHANNEL=113, the user is not in a channel
  • ERR_SIZE_TOO_LARGE=114, data size is too big
  • ERR_BITRATE_LIMIT=115, limited bitrate
  • ERR_TOO_MANY_DATA_STREAMS =116, too many data streams
  • ERR_STREAM_MESSAGE_TIMEOUT=117, data stream timed out

For more error code descriptions, see Error Codes and Warning Codes

missed The number of lost messages.
cached The number of incoming cached messages when the data stream is interrupted.

TokenExpired Callback (onRequesttoken)

public void onRequesttoken();

When a token is specified by calling joinChannel(), if the SDK lost 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.

This callback notifies the application the need to generate a new token, and calls renewToken() to renew the token.

This function was previously provided when the callback reported onError(): ERR_TOKEN_EXPIRED(109), ERR_INVALID_TOKEN(110). Starting from v1.7.3, the old method still works, but it is recommended to use this callback.

Audio Mixing File Playback Finished Callback (onAudioMixingFinished)

public void onAudioMixingFinished();

This callback is triggered when the audio mixing file playback is finished after calling startAudioMixing. If you failed to execute the startAudioMixing method, it returns the error code in the onError callback.

Local Audio Effect Playback Finished Callback (onAudioEffectFinished)

public void onAudioEffectFinished(int soundId)

This callback is triggered when the local audio effect playback is finished.

Name Description
soundId ID of the audio effect. Each audio effect has a unique ID.