From 497ee3a522eb6f9647964a016ae44421657f5459 Mon Sep 17 00:00:00 2001
From: Zach Pomerantz <zmp@umich.edu>
Date: Mon, 19 Jun 2017 17:07:43 -0700
Subject: [PATCH] add Audio.inputLevel

---
 interface/src/scripting/Audio.cpp          | 37 ++++++++++++++++++++--
 interface/src/scripting/Audio.h            |  7 ++++
 libraries/audio-client/src/AudioClient.cpp |  2 ++
 libraries/audio-client/src/AudioClient.h   |  1 +
 4 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/interface/src/scripting/Audio.cpp b/interface/src/scripting/Audio.cpp
index 0b99e60c89..4576190413 100644
--- a/interface/src/scripting/Audio.cpp
+++ b/interface/src/scripting/Audio.cpp
@@ -23,9 +23,33 @@ QString Audio::HMD { "VR" };
 
 Setting::Handle<bool> enableNoiseReductionSetting { QStringList { Audio::AUDIO, "NoiseReduction" }, true };
 
+float Audio::loudnessToLevel(float loudness) {
+    const float LOG2 = log(2.0f);
+    const float METER_LOUDNESS_SCALE = 2.8f / 5.0f;
+    const float LOG2_LOUDNESS_FLOOR = 11.0f;
+
+    float level = 0.0f;
+
+    loudness += 1.0f;
+    float log2loudness = logf(loudness) / LOG2;
+
+    if (log2loudness <= LOG2_LOUDNESS_FLOOR) {
+        level = (log2loudness / LOG2_LOUDNESS_FLOOR) * METER_LOUDNESS_SCALE;
+    } else {
+        level = (log2loudness - (LOG2_LOUDNESS_FLOOR - 1.0f)) * METER_LOUDNESS_SCALE;
+    }
+
+    if (level > 1.0f) {
+        level = 1.0;
+    }
+
+    return level;
+}
+
 Audio::Audio() : _devices(_contextIsHMD) {
-    auto client = DependencyManager::get<AudioClient>();
-    connect(client.data(), &AudioClient::muteToggled, this, &Audio::onMutedChanged);
+    auto client = DependencyManager::get<AudioClient>().data();
+    connect(client, &AudioClient::muteToggled, this, &Audio::onMutedChanged);
+    connect(client, &AudioClient::inputLoudnessChanged, this, &Audio::onInputLoudnessChanged);
     connect(this, &Audio::contextChanged, &_devices, &AudioDevices::onContextChanged);
     connect(&_devices._inputs, &AudioDeviceList::deviceChanged, this, &Audio::onInputChanged);
     enableNoiseReduction(enableNoiseReductionSetting.get());
@@ -88,6 +112,15 @@ void Audio::onInputChanged() {
     }
 }
 
+void Audio::onInputLoudnessChanged(float loudness) {
+    float level = loudnessToLevel(loudness);
+
+    if (_inputLevel != level) {
+        _inputLevel = level;
+        emit inputLevelChanged(_inputLevel);
+    }
+}
+
 QString Audio::getContext() const {
      return _contextIsHMD ? Audio::HMD : Audio::DESKTOP;
 }
diff --git a/interface/src/scripting/Audio.h b/interface/src/scripting/Audio.h
index d438df41ca..953727ede8 100644
--- a/interface/src/scripting/Audio.h
+++ b/interface/src/scripting/Audio.h
@@ -26,6 +26,7 @@ class Audio : public AudioScriptingInterface {
     Q_PROPERTY(bool muted READ isMuted WRITE setMuted NOTIFY mutedChanged)
     Q_PROPERTY(bool noiseReduction READ noiseReductionEnabled WRITE enableNoiseReduction NOTIFY noiseReductionChanged)
     Q_PROPERTY(float inputVolume READ getInputVolume WRITE setInputVolume NOTIFY inputVolumeChanged)
+    Q_PROPERTY(float inputLevel READ getInputLevel NOTIFY inputLevelChanged)
     Q_PROPERTY(QString context READ getContext NOTIFY contextChanged)
     Q_PROPERTY(AudioDevices* devices READ getDevices NOTIFY nop)
 
@@ -34,11 +35,14 @@ public:
     static QString HMD;
     static QString DESKTOP;
 
+    static float loudnessToLevel(float loudness);
+
     virtual ~Audio() {}
 
     bool isMuted() const { return _isMuted; }
     bool noiseReductionEnabled() const { return _enableNoiseReduction; }
     float getInputVolume() const { return _inputVolume; }
+    float getInputLevel() const { return _inputLevel; }
     QString getContext() const;
 
     void setMuted(bool muted);
@@ -54,12 +58,14 @@ signals:
     void mutedChanged(bool isMuted);
     void noiseReductionChanged(bool isEnabled);
     void inputVolumeChanged(float volume);
+    void inputLevelChanged(float level);
     void contextChanged(const QString& context);
 
 public slots:
     void onMutedChanged();
     void onContextChanged();
     void onInputChanged();
+    void onInputLoudnessChanged(float loudness);
 
 protected:
     // Audio must live on a separate thread from AudioClient to avoid deadlocks
@@ -68,6 +74,7 @@ protected:
 private:
 
     float _inputVolume { 1.0f };
+    float _inputLevel { 0.0f };
     bool _isMuted { false };
     bool _enableNoiseReduction;
     bool _contextIsHMD { false };
diff --git a/libraries/audio-client/src/AudioClient.cpp b/libraries/audio-client/src/AudioClient.cpp
index f32d37562a..fc54a04a5e 100644
--- a/libraries/audio-client/src/AudioClient.cpp
+++ b/libraries/audio-client/src/AudioClient.cpp
@@ -1023,6 +1023,8 @@ void AudioClient::handleAudioInput(QByteArray& audioBuffer) {
         emit inputReceived(audioBuffer);
     }
 
+    emit inputLoudnessChanged(_lastInputLoudness);
+
     // state machine to detect gate opening and closing
     bool audioGateOpen = (_lastInputLoudness != 0.0f);
     bool openedInLastBlock = !_audioGateOpen && audioGateOpen;  // the gate just opened
diff --git a/libraries/audio-client/src/AudioClient.h b/libraries/audio-client/src/AudioClient.h
index 01241938d9..54ce3aa6c2 100644
--- a/libraries/audio-client/src/AudioClient.h
+++ b/libraries/audio-client/src/AudioClient.h
@@ -210,6 +210,7 @@ signals:
     bool muteToggled();
     void mutedByMixer();
     void inputReceived(const QByteArray& inputSamples);
+    void inputLoudnessChanged(float loudness);
     void outputBytesToNetwork(int numBytes);
     void inputBytesFromNetwork(int numBytes);
     void noiseGateOpened();