IMediaEngine

The IMediaEngine class.

pullAudioFrame

Pulls the remote audio data.

virtual int pullAudioFrame(IAudioFrameObserver::AudioFrame* frame) = 0;

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.

Parameters

frame
Pointers to AudioFrame.

Returns

  • 0: Success.
  • < 0: Failure.

pushAudioFrame

Pushes the external audio frame.

virtual int pushAudioFrame(IAudioFrameObserver::AudioFrame* frame, rtc::track_id_t trackId = 0) = 0;

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.

virtual int pushVideoFrame(base::ExternalVideoFrame* frame, unsigned int videoTrackId = 0) = 0;

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.

Applicable scenarios

As of v4.2.6, the SDK supports the ID3D11Texture2D video format since , which is widely used in game scenarios. When you need to push this type of video frame to the SDK, call this method and set the format in the frame to VIDEO_TEXTURE_ID3D11TEXTURE2D, set the d3d11_texture_2d and texture_slice_index members, and set the format of the video frame to ID3D11Texture2D.

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.

virtual int registerAudioFrameObserver(IAudioFrameObserver* observer) = 0;

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. Set the value as NULL to release the instance. 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.

virtual int registerVideoEncodedFrameObserver(IVideoEncodedFrameObserver* observer) = 0;

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.

virtual int registerVideoFrameObserver(IVideoFrameObserver* observer) = 0;

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. To release the instance, set the value as NULL.

Returns

  • 0: Success.
  • < 0: Failure.

setExternalAudioSink

Sets the external audio sink.

virtual int setExternalAudioSink(bool enabled, int sampleRate, int channels) = 0;

Details

This method applies to scenarios where you want to use external audio data for playback. After you set the external audio sink, you can call pullAudioFrame to pull remote audio frames. The app can process the remote audio and play it with the audio effects that you want.

Parameters

enabled
Whether to enable or disable the external audio sink:
  • true: Enables the external audio sink.
  • false: (Default) Disables the external audio sink.
sampleRate

The sample rate (Hz) of the external audio sink, which can be set as 16000, 32000, 44100, or 48000.

channels
The number of audio channels of the external audio sink:
  • 1: Mono.
  • 2: Stereo.

Returns

  • 0: Success.
  • < 0: Failure.

setExternalAudioSource

Sets the external audio source parameters.

virtual int setExternalAudioSource(bool enabled,
                                   int sampleRate,
                                   int channels,
                                   bool localPlayback = false,
                                   bool publish = true) = 0;

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.

virtual int setExternalVideoSource(
    bool enabled, bool useTexture, EXTERNAL_VIDEO_SOURCE_TYPE sourceType = VIDEO_FRAME,
    rtc::SenderOptions encodedVideoOption = rtc::SenderOptions()) = 0;

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 EXTERNAL_VIDEO_SOURCE_TYPE.
encodedVideoOption
Video encoding options. This parameter needs to be set if sourceType is ENCODED_VIDEO_FRAME. To set this parameter, contact technical support.

Returns

  • 0: Success.
  • < 0: Failure.