WebRTC“audioOutputLevel”的值意味着

Question

我在webrtc stats API网站上阅读了关于音频级文档：

Identifiers for WebRTC's Statistics API

在此网站上，他们将AudioLevel值描述为0..1。当我获得音频流的统计数据并打印到控制台时。结果如下：

▿ 29 key/value pairs
 ▿ (2 elements)
    - key: "ssrc"
    - value: "2726297394"
  ▿ (2 elements)
    - key: "googDecodingPLC"
    - value: "18"
  ▿ (2 elements)
    - key: "googSecondaryDecodedRate"
    - value: "0"
  ▿ (2 elements)
    - key: "googDecodingCTN"
    - value: "911"
  ▿ (2 elements)
    - key: "googJitterReceived"
    - value: "5"
  ▿ (2 elements)
    - key: "transportId"
    - value: "Channel-audio-1"
  ▿ (2 elements)
    - key: "googExpandRate"
    - value: "0.0194092"
  ▿ (2 elements)
    - key: "packetsReceived"
    - value: "439"
  ▿ (2 elements)
    - key: "audioOutputLevel"
    - value: "28025"
  ▿ (2 elements)
    - key: "googDecodingMuted"
    - value: "43"
  ▿ (2 elements)
    - key: "googDecodingPLCCNG"
    - value: "44"
  ▿ (2 elements)
    - key: "totalSamplesDuration"
    - value: "9.11"
  ▿ (2 elements)
    - key: "googPreemptiveExpandRate"
    - value: "0.0101318"
  ▿ (2 elements)
    - key: "googSpeechExpandRate"
    - value: "0.0194092"
  ▿ (2 elements)
    - key: "packetsLost"
    - value: "1"
  ▿ (2 elements)
    - key: "googPreferredJitterBufferMs"
    - value: "120"
  ▿ (2 elements)
    - key: "googDecodingCTSG"
    - value: "0"
  ▿ (2 elements)
    - key: "googCurrentDelayMs"
    - value: "158"
  ▿ (2 elements)
    - key: "googCaptureStartNtpTimeMs"
    - value: "0"
  ▿ (2 elements)
    - key: "mediaType"
    - value: "audio"
  ▿ (2 elements)
    - key: "bytesReceived"
    - value: "41628"
  ▿ (2 elements)
    - key: "googCodecName"
    - value: "opus"
  ▿ (2 elements)
    - key: "googDecodingCNG"
    - value: "0"
  ▿ (2 elements)
    - key: "totalAudioEnergy"
    - value: "3.47756"
  ▿ (2 elements)
    - key: "googJitterBufferMs"
    - value: "120"
  ▿ (2 elements)
    - key: "googSecondaryDiscardedRate"
    - value: "0"
  ▿ (2 elements)
    - key: "googAccelerateRate"
    - value: "0.00354004"
  ▿ (2 elements)
    - key: "googDecodingNormal"
    - value: "849"
  ▿ (2 elements)
    - key: "googTrackId"
    - value: "OCVMXiq8"

我没有找到关键的“audioLevel”作为文档描述，但找到了“audioOutputLevel”。然后，这个值意味着什么，或者它可以转换为“audioLevel”值，如上文所述

---

更新以下是我用来获取统计数据的示例代码

for receive in (self.client!.peerConnection!.receivers) {
                self.client!.peerConnection!.stats(for: receive.track!, statsOutputLevel: .debug, completionHandler: { reports in
                    for report in reports {
                        print("-------- report id \(report.reportId) in time \(Date().timeIntervalSince1970)")
                        dump(report.values)
                        print("-----------------------------------------")
                    }

                })
            }

Answer 1

您似乎正在使用“遗留”getStats API，即您调用

pc.getStats(function(res) {
  // show result
})

其中这称为aduioOutputLevel。如果你使用

pc.getStats().then(function(stats) {
  // show result
})

它应该显示为audioLevel。

https://webrtc.github.io/samples/src/content/peerconnection/constraints/展示了一个完整的例子。