Call Stats

Sometimes you need a way to capture certain metrics related to a call. This may be helpful if you want to tailor the experience to your users or debug issues. Typical metrics of interest are audio/video bitrate, round trip time, total consumed bandwidth and packet loss.

100ms SDK provides this data via dedicated delegate callbacks found in HMSStatsListener. These will be called with a fixed interval of one second after a room has been joined. You can get stats on a per-track basis ( onRemoteAudioStats) or as an overall summary (onRTCStats)

HMSStatsListener callbacks

Here is the full list of callbacks:

/// This callback provides stats for a local audio track.
void onLocalAudioStats({required HMSLocalAudioStats hmsLocalAudioStats, required HMSLocalAudioTrack track, required HMSPeer peer})

/// This callback provides stats for a local video track with all the available layers.
void onLocalVideoStats({required List<HMSLocalVideoStats> hmsLocalVideoStats, required HMSLocalVideoTrack track, required HMSPeer peer})

/// This callback provides stats for a remote audio track.
void onRemoteAudioStats({required HMSRemoteAudioStats hmsRemoteAudioStats, required HMSRemoteAudioTrack track, required HMSPeer peer})

/// This callback provides stats for a remote video track.
void onRemoteVideoStats({required HMSRemoteVideoStats hmsRemoteVideoStats, required HMSRemoteVideoTrack track, required HMSPeer peer})

/// This callback provides combined stats for the session.
void onRTCStats({required HMSRTCStatsReport hmsrtcStatsReport})

To listen to these callbacks we will need to attach HMSStatsListener and override the above methods. Let's see how we can listen to these callbacks:

class StatsReport implements HMSStatsListener{}

//hmsStatsListener is an instance of HMSStatsListener
hmsSDK.addStatsListener(listener: hmsStatsListener);

class StatsReport implements HMSStatsListener{

  @override
  void onLocalAudioStats(
      {required HMSLocalAudioStats hmsLocalAudioStats,
      required HMSLocalAudioTrack track,
      required HMSPeer peer}) {}

  @override
  void onLocalVideoStats(
      {required List<HMSLocalVideoStats> hmsLocalVideoStats,
      required HMSLocalVideoTrack track,
      required HMSPeer peer}) {}

  @override
  void onRemoteAudioStats(
      {required HMSRemoteAudioStats hmsRemoteAudioStats,
      required HMSRemoteAudioTrack track,
      required HMSPeer peer}) {}

  @override
  void onRemoteVideoStats(
      {required HMSRemoteVideoStats hmsRemoteVideoStats,
      required HMSRemoteVideoTrack track,
      required HMSPeer peer}) {}

  @override
  void onRTCStats({required HMSRTCStatsReport hmsrtcStatsReport}) {}
}

//hmsStatsListener is an instance of HMSStatsListener which we passed in addStatsListener
hmsSDK.removeStatsListener(listener: hmsStatsListener);

Supplementary bytes

HMSRTCStatsReport

This class will contain the combined stats for the room.

class HMSRTCStats {
  // Total bytes sent in the current session.
  int bytesSent;
  // Total bytes received in the current session.
  int bytesReceived;
  // Total packets received in the current session.
  int packetsReceived;
  // Total packets lost in the current session.
  int packetsLost;
  // Total outgoing bitrate observed since the previous report.
  double bitrateSent;
  // Total incoming bitrate observed since the previous report in Kb/s.
  double bitrateReceived;
  // Average round trip time observed since the previous report in Kb/s.
  double roundTripTime;
}

class HMSRTCStatsReport {
  // Combined audio + video values
  HMSRTCStats combined;
  // Summary of all audio tracks
  HMSRTCStats audio;
  // Summary of all video tracks
  HMSRTCStats video;
}

HMSLocalAudioStats

This class contains stats related to the local audio track.

class HMSLocalAudioStats {
  // Round trip time observed since the previous report
  double roundTripTime;
  // Total bytes sent by this track in the current session
  int bytesSent;
  // Outgoing bitrate of this track observed since the previous report in Kb/s
  double bitrate;
}

HMSLocalVideoStats

This class contains stats related to local video track.

class HMSLocalVideoStats {
	// Round trip time observed since the previous report.
  double roundTripTime;
  // Total bytes sent by this track in the current session.
  int bytesSent;
  // Outgoing bitrate of this track observed since the previous report in Kb/s.
  double bitrate;
  // Resolution of video frames being sent.
  double frameRate;
  // Frame rate of video frames being sent (FPS).
  HMSResolution resolution;
  ///Reason for quality limitations
  HMSQualityLimitationReasons? hmsQualityLimitationReasons;
  ///Simulcast Layer
  HMSSimulcastLayer? hmsLayer;
}

HMSRemoteAudioStats

This class contains stats related to the remote audio track.

class HMSRemoteAudioStats {
  // Packet Jitter measured in seconds for this track. Calculated as defined in section 6.4.1. of RFC3550.
  double jitter;
  // Total bytes received by this track in the current session.
  int bytesReceived;
  // Incoming bitrate of this track observed since the previous report in Kb/s.
  double bitrate;
  // Total packets received by this track in the current session.
  int packetsReceived;
  // Total packets lost by this track in the current session.
  int packetsLost;
}

HMSRemoteVideoStats

This class contains stats related to the remote video track.

class HMSRemoteVideoStats {
  // Packet Jitter measured in seconds for this track. Calculated as defined in section 6.4.1. of RFC3550.
  double jitter;
  // Total bytes received by this track in the current session.
  int bytesReceived;
  // Incoming bitrate of this track observed since the previous report in Kb/s.
  double bitrate;
  // Total packets received by this track in the current session.
  int packetsReceived;
  // Total packets lost by this track in the current session.
  int packetsLost;
  // Resolution of video frames being received.
  HMSResolution resolution;
  // Frame rate of video frames being received (FPS).
  double frameRate;
}