feat(settings): Add audio quality setting

Fixes #4693

src/core/coreav.cpp

@@ -48,7 +48,7 @@
  * @brief Sent when a call was ended by the peer.
  * @param friendId Id of friend in call list.
  *
- * @var CoreAV::AUDIO_DEFAULT_BITRATE
+ * @var CoreAV::audioBitrate
  * @brief In kb/s. More than enough for Opus.
  *
  * @var CoreAV::VIDEO_DEFAULT_BITRATE
@@ -236,7 +236,7 @@ bool CoreAV::answerCall(uint32_t friendNum)
     qDebug() << QString("answering call %1").arg(friendNum);
     assert(calls.contains(friendNum));
     TOXAV_ERR_ANSWER err;
-    if (toxav_answer(toxav, friendNum, AUDIO_DEFAULT_BITRATE, VIDEO_DEFAULT_BITRATE, &err)) {
+    if (toxav_answer(toxav, friendNum, audioBitrate, VIDEO_DEFAULT_BITRATE, &err)) {
         calls[friendNum].inactive = false;
         return true;
     } else {
@@ -271,7 +271,7 @@ bool CoreAV::startCall(uint32_t friendNum, bool video)
     }
 
     uint32_t videoBitrate = video ? VIDEO_DEFAULT_BITRATE : 0;
-    if (!toxav_call(toxav, friendNum, AUDIO_DEFAULT_BITRATE, videoBitrate, nullptr))
+    if (!toxav_call(toxav, friendNum, audioBitrate, videoBitrate, nullptr))
         return false;
 
     auto call = calls.insert({friendNum, video, *this});

src/core/coreav.h

@@ -81,6 +81,7 @@ public:
                                   uint8_t channels, unsigned sample_rate, void* core);
     static void invalidateGroupCallPeerSource(int group, int peer);
 
+    uint32_t audioBitrate = 64;
 public slots:
     bool startCall(uint32_t friendNum, bool video = false);
     bool answerCall(uint32_t friendNum);
@@ -111,7 +112,6 @@ private:
                                    int32_t ystride, int32_t ustride, int32_t vstride, void* self);
 
 private:
-    static constexpr uint32_t AUDIO_DEFAULT_BITRATE = 64;
     static constexpr uint32_t VIDEO_DEFAULT_BITRATE = 6144;
 
 private:

src/widget/form/settings/avform.cpp

@@ -121,6 +121,7 @@ void AVForm::showEvent(QShowEvent* event)
     getAudioInDevices();
     createVideoSurface();
     getVideoDevices();
+    fillAudioQualityComboBox();
 
     if (!subscribedToAudioIn) {
         // TODO: This should not be done in show/hide events
@@ -333,6 +334,24 @@ void AVForm::fillScreenModesComboBox()
     videoModescomboBox->blockSignals(previouslyBlocked);
 }
 
+void AVForm::fillAudioQualityComboBox()
+{
+    bool previouslyBlocked = audioQualityComboBox->blockSignals(true);
+    audioQualityComboBox->clear();
+
+    QString name;
+    name = tr("High (64 kbps)");
+    audioQualityComboBox->addItem(name);
+    name = tr("Medium (32 kbps)");
+    audioQualityComboBox->addItem(name);
+    name = tr("Low (16 kbps)");
+    audioQualityComboBox->addItem(name);
+    name = tr("Very Low (8 kbps)");
+    audioQualityComboBox->addItem(name);
+
+    audioQualityComboBox->blockSignals(previouslyBlocked);
+}
+
 void AVForm::updateVideoModes(int curIndex)
 {
     if (curIndex < 0 || curIndex >= videoDeviceList.size()) {
@@ -408,6 +427,27 @@ void AVForm::on_videoDevCombobox_currentIndexChanged(int index)
         Core::getInstance()->getAv()->sendNoVideo();
 }
 
+void AVForm::on_audioQualityComboBox_currentIndexChanged(int index)
+{
+    uint32_t bitrate;
+    switch (index) {
+    case 1:
+        bitrate = 32;
+        break;
+    case 2:
+        bitrate = 16;
+        break;
+    case 3:
+        bitrate = 8;
+        break;
+    default:
+        bitrate = 64;
+        break;
+    }
+   
+    Core::getInstance()->getAv()->audioBitrate = bitrate;
+}
+
 void AVForm::getVideoDevices()
 {
     QString settingsInDev = Settings::getInstance().getVideoDev();

src/widget/form/settings/avform.h

@@ -52,6 +52,7 @@ private:
     void selectBestModes(QVector<VideoMode>& allVideoModes);
     void fillCameraModesComboBox();
     void fillScreenModesComboBox();
+    void fillAudioQualityComboBox();
     int searchPreferredIndex();
 
     void createVideoSurface();
@@ -66,6 +67,7 @@ private slots:
     void on_playbackSlider_valueChanged(int value);
     void on_cbEnableTestSound_stateChanged();
     void on_microphoneSlider_valueChanged(int value);
+    void on_audioQualityComboBox_currentIndexChanged(int index);
 
     // camera
     void on_videoDevCombobox_currentIndexChanged(int index);

src/widget/form/settings/avform.ui

@@ -108,7 +108,27 @@
             </property>
            </widget>
           </item>
-          <item row="4" column="0" colspan="3">
+          <item row="4" column="0">
+           <widget class="QLabel" name="audioQualityLabel">
+            <property name="text">
+             <string>Audio Quality</string>
+            </property>
+           </widget>
+          </item>
+          <item row="4" column="1" colspan="2">
+           <widget class="QComboBox" name="audioQualityComboBox">
+            <property name="sizePolicy">
+             <sizepolicy hsizetype="Expanding" vsizetype="Fixed">
+              <horstretch>0</horstretch>
+              <verstretch>0</verstretch>
+             </sizepolicy>
+            </property>
+            <property name="toolTip">
+             <string>Transmitted audio quality. Lower this setting if your bandwidth is not high enough or if you want to lower the internet usage.</string>
+            </property>
+           </widget>
+          </item>
+          <item row="5" column="0" colspan="3">
            <widget class="QCheckBox" name="cbEnableBackend2">
             <property name="enabled">
              <bool>true</bool>