通话质量检测

BRTC 提供 onStatistics 回调事件，它会每隔两秒钟一次向应用层上报当前网络质量，其参数包括本地推流和远端拉流质量两个部分：

示例代码

#pragma mark - >>>>>>>>>>>>>>>>>>>BRTC 回调<<<<<<<<<<<<<<<<<<<<<<
- (void)onStatistics:(BRTCStatistics *)statistics {
  NSMutableString *text = [NSMutableString string];
  [text appendFormat:@"RTT: %d ms \n", statistics.rtt];
  [text appendFormat:@"up Packet Loss: %u\n",statistics.upLoss];
  [text appendFormat:@"down Packet Loss: %u\n",statistics.downLoss];
  [text appendFormat:@"cpu usage: %u\n",statistics.cpu];
  for (BRTCLocalStatistics *local in statistics) {
    [text appendFormat:@"Resolution: %d X %d\n",local.width, local.height];
    [text appendFormat:@"Video Send Bitrate: %.2u kps \n", local.videoBitrate];
    [text appendFormat:@"Audio Send Bitrate: %.2u kps \n", local.audioBitrate];
    [text appendFormat:@"Video Send FPS: %.1u fps \n", local.frameRate];
    [text appendFormat:@"local streamType: %d \n", local.streamType];
  }
  for (remoteStatistics *remote in statistics) {
    [text appendFormat:@"Resolution: %d X %d\n", remote.width,remote.height];
    [text appendFormat:@"Audio Recv Bitrate: %.2u kps \n", remote.audioBitrate];
    [text appendFormat:@"Video Recv Bitrate: %.2u kps \n", remote.videoBitrate];
    [text appendFormat:@"Video Recv FPS: %.1u fps \n", remote.frameRate];
    [text appendFormat:@"Delay: %d ms \n", remote.jitterBufferDelay];
    [text appendFormat:@"remote stream type: %d \n", remote.streamType];
  }
  [self appendLog:[NSString stringWithFormat:@"quality: %@", text]];
}

流类型 BRTCVideoStreamType 定义如下：

• BRTCVideoStreamTypeBig(0): 主画面视频流
• BRTCVideoStreamTypeSmall(1): 小画面视频流
• BRTCVideoStreamTypeSub(2): 辅流（屏幕分享）