Video SDK for C++
- API Overview
  Agora provides ensured quality of experience (QoE) for worldwide Internet-based voice and video communications through SD-RTN™.
- IRtcEngine
  The basic interface of the Agora SDK that implements the core functions of real-time communication.
- IRtcEngineEx
  This interface class contains multi-channel methods.
- IRtcEngineEventHandler
  The SDK uses the IRtcEngineEventHandler interface to send event notifications to your app. Your app can get those notifications through methods that inherit this interface.
- IMediaPlayer
  This class provides media player functions and supports multiple instances.
- IAudioEncodedFrameObserver
  The encoded audio observer.
- IAudioDeviceManager
  Audio device management methods.
- IAudioDeviceCollection
  The IAudioDeviceCollection interface. You can get the information of audio devices with this interface.
- IVideoDeviceManager
  Video device management methods.
- IVideoDeviceCollection
  You can get the information of video devices with this interface.
- IMediaEngine
  The IMediaEngine class.
- IMediaPlayerCacheManager
  This class provides methods to manage cached media files.
- IMediaPlayerCustomDataProvider
  The callback for custom media resource files.
- IMediaPlayerSourceObserver
  Provides callbacks for media players.
- IAudioFrameObserver
  The audio frame observer.
- IAudioFrameObserverBase
  The audio frame observer.
- IAudioSpectrumObserver
  The audio spectrum observer.
- IPacketObserver
  The definition of IPacketObserver.
- IMetadataObserver
  The metadata observer.
- IVideoEncodedFrameObserver
  Receives encoded video images.
- IVideoFrameObserver
  The IVideoFrameObserver class.
- ILocalSpatialAudioEngine
  This class calculates user positions through the SDK to implement the spatial audio effect.
- IScreenCaptureSourceList
  The IScreenCaptureSourceList class. This class is returned in the getScreenCaptureSources method.
- Struct and Enum
  This page lists all the definitions of Struct and the enums for C++.

IAudioFrameObserver

The audio frame observer.

You can call registerAudioFrameObserver to register or unregister the IAudioFrameObserver audio frame observer.

onPlaybackAudioFrameBeforeMixing

Retrieves the audio frame of a specified user before mixing.

virtual bool onPlaybackAudioFrameBeforeMixing(const char* channelId, rtc::uid_t uid, AudioFrame& audioFrame) = 0;

Parameters

channelId: The channel ID.
uid: The user ID of the specified user.
audioFrame: The raw audio data. See AudioFrame.

Returns

Without practical meaning.