Report In-call Statistics

The Agora RTC SDK triggers callbacks related to the quality of the call and live streaming in real-time, from which you can learn about users' interaction experience, and conduct corresponding troubleshooting and experience optimization.

This page describes how to understand the information returned by the callbacks and how to use these callbacks.

Understand the tech

After a user successfully joins the channel, the SDK triggers a series of callbacks with a two-second callback period, including the following: interaction statistics report, local and remote audio and video streams statistic report.

When the user's audio or video state changes, the SDK triggers a callback to report the latest audio or video state and the reason for the state change.

Statistics report

The reportRtcStats callback reports call statistics. You can learn about the duration, the number of users in the channel, the system CPU usage, the application CPU usage, and so on.

Audio quality report

This section describes the user's audio quality report, including local audio stream statistics, local audio stream state change, remote audio stream statistics, and remote audio stream state change.

Statistics of local audio streams

The localAudioStats callback, which is triggered once every two seconds, reports the statistics of the audio streams sent. You can learn about the following important statistics:

• The number of audio channels.
• The actual sample rate of the audio streams sent in the reported interval.
• The average sending bitrate in the reported interval.

State changes of local audio streams

When the state of local audio changes, such as the state of audio recording or audio encoding changes, the SDK triggers the localAudioStateChange callback to report the current state. You can troubleshoot with the error code when exceptions occur.

Statistics of remote audio streams

The following figure shows the transmission process between app clients.

The remoteAudioStats callback reports the audio statistics of each remote user in the Communication profile or remote host in the LiveBroadcasting profile in the current call, including the quality of the remote audio streams (see quality rating table), the number of audio channels, and so on.

To analyse statistics more closely linked to the user's experience and audio transmission quality, use remoteAudioStats. Even if network packet loss occurs, users might find the overall audio quality acceptable because the audio frame loss rate of the received audio streams might not be high due to the anti-packet-loss and congestion control methods, such as forward error correction (FEC), retransmissions and bandwidth estimation.

State changes of remote audio streams

When the audio state of a remote user in the Communication profile or remote host in the LiveBroadcasting profile changes, the SDK triggers the remoteAudioStateChangedOfUid callback to report the current state and the reason for the state change.

Video quality report

This section describes the user's video quality report, including local video stream statistics, local video stream state change, remote video stream statistics, and remote video stream state change.

Statistics of local video streams

The localVideoStats callback reports the statistics of the video streams sent. You can learn about the dimensions of the encoding frame, the target bitrate of the encoder, the bitrate of the video sent in the reported interval, and so on.

State changes of local video streams

When the state of the local video changes, the SDK triggers the localVideoStateChangedOfState callback to report the current state. You can troubleshoot with the error code when exceptions occur.

Statistics of remote video streams

The following figure shows the transmission process between app clients.

The remoteVideoStats callback reports the video statistics of each remote user in the Communication profile or remote host in the LiveBroadcasting profile in the current call. You can learn about their video dimensions, the type of video streams, the bitrate of the video received in the reported interval, and so on.

State changes of remote video streams

When the video state of a remote user in the Communication profile or remote host in the LiveBroadcasting profile changes, the SDK triggers the remoteVideoStateChangedOfUid callback to report the current state and the reason for the state change.

Implementation

1. Ensure that you have a project that has implemented the basic real-time engagement functionality. For details, see the following quickstart guides:

   • iOS: Start a Video Call or Start Interactive Live Streaming
   • macOS: Start a Video Call or Start Interactive Live Streaming

2. Implement the following real-time interaction quality statistic callbacks and audio or video state callbacks in AgoraRtcEngineDelegate to monitor user interaction experience.

   • reportRtcStats: Reports real-time interaction statistics.
   • localAudioStats: Reports statistics of the audio stream sent.
   • localAudioStateChange: Reports the local audio stream state changes.
   • remoteAudioStats: Reports statistics of a remote audio stream received.
   • remoteAudioStateChangedOfUid: Reports the remote audio stream state changes.
   • localVideoStats: Reports statistics of the video stream sent.
   • localVideoStateChangedOfState: Reports the local video stream state changes.
   • remoteVideoStats: Reports statistics of a remote video stream received.
   • remoteVideoStateChangedOfUid: Reports the remote video stream state changes.

extension JoinChannelVideoMain: AgoraRtcEngineDelegate {

    func rtcEngine(_ engine: AgoraRtcEngineKit, reportRtcStats stats: AgoraChannelStats) {
        localVideo.statsInfo?.updateChannelStats(stats)
    }

    func rtcEngine(_ engine: AgoraRtcEngineKit, localVideoStats stats: AgoraRtcLocalVideoStats) {
        localVideo.statsInfo?.updateLocalVideoStats(stats)
    }

    func rtcEngine(_ engine: AgoraRtcEngineKit, localAudioStats stats: AgoraRtcLocalAudioStats) {
        localVideo.statsInfo?.updateLocalAudioStats(stats)
    }

    func rtcEngine(_ engine: AgoraRtcEngineKit, remoteVideoStats stats: AgoraRtcRemoteVideoStats) {
        remoteVideo.statsInfo?.updateVideoStats(stats)
    }

    func rtcEngine(_ engine: AgoraRtcEngineKit, remoteAudioStats stats: AgoraRtcRemoteAudioStats) {
        remoteVideo.statsInfo?.updateAudioStats(stats)
    }
}

API Reference

• networkQuality
• reportRtcStats
• localAudioStats
• localAudioStateChange
• remoteAudioStats
• remoteAudioStateChangedOfUid
• localVideoStats
• localVideoStateChangedOfState
• remoteVideoStats
• remoteVideoStateChangedOfUid

Quality rating table