IMediaEngine

The IMediaEngine class.

addListener

Adds one IMediaEngineEvent listener.

addListener?<EventType extends keyof IMediaEngineEvent>(
      eventType: EventType,
      listener: IMediaEngineEvent[EventType]
    ): void;

Details

After calling this method, you can listen for the corresponding events in the IMediaEngine object and obtain data through IMediaEngineEvent. Depending on your project needs, you can add multiple listeners for the same event.

Parameters

eventType
The name of the target event to listen for. See IMediaEngineEvent.
listener
The callback function for eventType. Take adding a listener for onPlaybackAudioFrameBeforeMixing as an example:
const onPlaybackAudioFrameBeforeMixing = (channelId: string, uid: number, audioFrame: AudioFrame) => {};
engine.addListener('onPlaybackAudioFrameBeforeMixing', onPlaybackAudioFrameBeforeMixing);

pullAudioFrame

Pulls the remote audio data.

abstract pullAudioFrame(): AudioFrame;

Details

Before calling this method, you need to call setExternalAudioSink to notify the app to enable and set the external rendering.

After a successful method call, the app pulls the decoded and mixed audio data for playback.

Attention:
  • This method only supports pulling data from custom audio source. If you need to pull the data captured by the SDK, do not call this method.
  • Call this method after joining a channel.
  • Once you enable the external audio sink, the app will not retrieve any audio data from the onPlaybackAudioFrame callback.
  • The difference between this method and the onPlaybackAudioFrame callback is as follows:
    • The SDK sends the audio data to the app through the onPlaybackAudioFrame callback. Any delay in processing the audio frames may result in audio jitter.
    • After a successful method call, the app automatically pulls the audio data from the SDK. After setting the audio data parameters, the SDK adjusts the frame buffer and avoids problems caused by jitter in the external audio playback.

Returns

  • The AudioFrame instance, if the method call succeeds.
  • An error code, if the call fails,.

pushAudioFrame

Pushes the external audio frame.

abstract pushAudioFrame(frame: AudioFrame, trackId?: number): number;

Parameters

frame
The external audio frame. See AudioFrame.
trackId
The audio track ID. If you want to publish a custom external audio source, set this parameter to the ID of the corresponding custom audio track you want to publish.

Returns

  • 0: Success.
  • < 0: Failure.

pushVideoFrame

Pushes the external raw video frame to the SDK.

abstract pushVideoFrame(
    frame: ExternalVideoFrame,
    videoTrackId?: number
  ): number;

Details

If you call createCustomVideoTrack method to get the video track ID, set the customVideoTrackId parameter to the video track ID you want to publish in the ChannelMediaOptions of each channel, and set the publishCustomVideoTrack parameter to true, you can call this method to push the unencoded external video frame to the SDK.

Parameters

frame

The external raw video frame to be pushed. See ExternalVideoFrame.

videoTrackId
The video track ID returned by calling the createCustomVideoTrack method. The default value is 0.

Returns

  • 0: Success.
  • < 0: Failure.

registerAudioFrameObserver

Registers an audio frame observer object.

abstract registerAudioFrameObserver(observer: IAudioFrameObserver): number;

Details

Call this method to register an audio frame observer object (register a callback). When you need the SDK to trigger onMixedAudioFrame, onRecordAudioFrame, onPlaybackAudioFrame or onEarMonitoringAudioFrame callback, you need to use this method to register the callbacks.

Attention: Ensure that you call this method before joining a channel.

Parameters

observer

The observer instance. See IAudioFrameObserver. Agora recommends calling this method after receiving onLeaveChannel to release the audio observer object.

Returns

  • 0: Success.
  • < 0: Failure.

registerVideoEncodedFrameObserver

Registers a receiver object for the encoded video image.

abstract registerVideoEncodedFrameObserver(
    observer: IVideoEncodedFrameObserver
  ): number;

Details

If you only want to observe encoded video frames (such as h.264 format) without decoding and rendering the video, Agora recommends that you implement one IVideoEncodedFrameObserver class through this method.

If you want to obtain the original video data of some remote users (referred to as group A) and the encoded video data of other remote users (referred to as group B), you can refer to the following steps:
  1. Call registerVideoFrameObserver to register the raw video frame observer before joining the channel.
  2. Call registerVideoEncodedFrameObserver to register the encoded video frame observer before joining the channel.
  3. After joining the channel, get the user IDs of group B users through onUserJoined, and then call setRemoteVideoSubscriptionOptions to set the encodedFrameOnly of this group of users to true.
  4. Call muteAllRemoteVideoStreams(false)to start receiving the video streams of all remote users. Then:
    • The raw video data of group A users can be obtained through the callback in IVideoFrameObserver, and the SDK renders the data by default.
    • The encoded video data of group B users can be obtained through the callback in IVideoEncodedFrameObserver.
Attention:
  • Call this method before joining a channel.

Parameters

observer
The video frame observer object. See IVideoEncodedFrameObserver.

Returns

  • 0: Success.
  • < 0: Failure.

registerVideoFrameObserver

Registers a raw video frame observer object.

abstract registerVideoFrameObserver(observer: IVideoFrameObserver): number;

Details

If you want to observe raw video frames (such as YUV or RGBA format), Agora recommends that you implement one IVideoFrameObserver class with this method.

When calling this method to register a video observer, you can register callbacks in the IVideoFrameObserver class as needed. After you successfully register the video frame observer, the SDK triggers the registered callbacks each time a video frame is received.

If you want to obtain the original video data of some remote users (referred to as group A) and the encoded video data of other remote users (referred to as group B), you can refer to the following steps:
  1. Call registerVideoFrameObserver to register the raw video frame observer before joining the channel.
  2. Call registerVideoEncodedFrameObserver to register the encoded video frame observer before joining the channel.
  3. After joining the channel, get the user IDs of group B users through onUserJoined, and then call setRemoteVideoSubscriptionOptions to set the encodedFrameOnly of this group of users to true.
  4. Call muteAllRemoteVideoStreams(false)to start receiving the video streams of all remote users. Then:
    • The raw video data of group A users can be obtained through the callback in IVideoFrameObserver, and the SDK renders the data by default.
    • The encoded video data of group B users can be obtained through the callback in IVideoEncodedFrameObserver.
Attention:
  • Ensure that you call this method before joining a channel.
  • When handling the video data returned in the callbacks, pay attention to the changes in the width and height parameters, which may be adapted under the following circumstances:
    • When network conditions deteriorate, the video resolution decreases incrementally.
    • If the user adjusts the video profile, the resolution of the video returned in the callbacks also changes.

Parameters

observer
The observer instance. See IVideoFrameObserver.

Returns

  • 0: Success.
  • < 0: Failure.

removeAllListeners

Removes all listeners for the specified event.

removeAllListeners?<EventType extends keyof IMediaEngineEvent>(
      eventType?: EventType
    ): void;

Parameters

eventType
The name of the target event to listen for. See IMediaEngineEvent.

removeListener

Removes the specified IMediaEngineEvent listener.

removeListener?<EventType extends keyof IMediaEngineEvent>(
      eventType: EventType,
      listener: IMediaEngineEvent[EventType]
    ): void;

Details

For listened events, if you no longer need to receive the callback message, you can call this method to remove the corresponding listener.

Parameters

eventType
The name of the target event to listen for. See IMediaEngineEvent.
listener
The callback function for eventType. Must pass in the same function object in addListener. Take removing the listener for onJoinChannelSuccess as an example: 
// Create an onPlaybackAudioFrameBeforeMixing object
const onPlaybackAudioFrameBeforeMixing = (channelId: string, uid: number, audioFrame: AudioFrame) => {};
// Add one onPlaybackAudioFrameBeforeMixing listener
engine.addListener('onPlaybackAudioFrameBeforeMixing', onPlaybackAudioFrameBeforeMixing);
// Remove the onPlaybackAudioFrameBeforeMixing listener
engine.removeListener('onPlaybackAudioFrameBeforeMixing', onPlaybackAudioFrameBeforeMixing);

setExternalAudioSource

Sets the external audio source parameters.

abstract setExternalAudioSource(
    enabled: boolean,
    sampleRate: number,
    channels: number,
    localPlayback?: boolean,
    publish?: boolean
  ): number;

Details

Deprecated:
This method is deprecated, use createCustomAudioTrack instead.
Attention: Call this method before joining a channel.

Parameters

enabled
Whether to enable the external audio source:
  • true: Enable the external audio source.
  • false: (Default) Disable the external audio source.
sampleRate
The sample rate (Hz) of the external audio source which can be set as 8000, 16000, 32000, 44100, or 48000.
channels
The number of channels of the external audio source, which can be set as 1 (Mono) or 2 (Stereo).
localPlayback
Whether to play the external audio source:
  • true: Play the external audio source.
  • false: (Default) Do not play the external source.
publish
Whether to publish audio to the remote users:
  • true: (Default) Publish audio to the remote users.
  • false: Do not publish audio to the remote users.

Returns

  • 0: Success.
  • < 0: Failure.

setExternalVideoSource

Configures the external video source.

abstract setExternalVideoSource(
    enabled: boolean,
    useTexture: boolean,
    sourceType?: ExternalVideoSourceType,
    encodedVideoOption?: SenderOptions
  ): number;

Details

Attention: Call this method before joining a channel.

Parameters

enabled
Whether to use the external video source:
  • true: Use the external video source. The SDK prepares to accept the external video frame.
  • false: (Default) Do not use the external video source.
useTexture
Whether to use the external video frame in the Texture format.
  • true: Use the external video frame in the Texture format.
  • false: (Default) Do not use the external video frame in the Texture format.
sourceType
Whether the external video frame is encoded. See ExternalVideoSourceType.
encodedVideoOption
Video encoding options. This parameter needs to be set if sourceType is EncodedVideoFrame. To set this parameter, contact technical support.

Returns

  • 0: Success.
  • < 0: Failure.

unregisterAudioFrameObserver

Unregisters an audio frame observer.

abstract unregisterAudioFrameObserver(observer: IAudioFrameObserver): number;

Parameters

observer
The audio frame observer, reporting the reception of each audio frame. See IAudioFrameObserver.

Returns

  • 0: Success.
  • < 0: Failure.

unregisterVideoEncodedFrameObserver

Unregisters a receiver object for the encoded video frame.

abstract unregisterVideoEncodedFrameObserver(
    observer: IVideoEncodedFrameObserver
  ): number;

Parameters

observer
The video observer, reporting the reception of each video frame. See IVideoEncodedFrameObserver.

Returns

  • 0: Success.
  • < 0: Failure.

unregisterVideoFrameObserver

Unregisters the video frame observer.

abstract unregisterVideoFrameObserver(observer: IVideoFrameObserver): number;

Parameters

observer
The video observer, reporting the reception of each video frame. See IVideoFrameObserver.

Returns

  • 0: Success.
  • < 0: Failure.