Add support for bs2b

Improve headphone listening of stereo audio records

src/engine/enginebase.cpp

@@ -67,6 +67,7 @@ Engine::Base::Base(const EngineType type, QObject *parent)
       proxy_authentication_(false),
       channels_enabled_(false),
       channels_(0),
+      bs2b_enabled_(false),
       about_to_end_emitted_(false) {}
 
 Engine::Base::~Base() = default;
@@ -142,6 +143,8 @@ void Engine::Base::ReloadSettings() {
   fadeout_pause_duration_ = s.value("FadeoutPauseDuration", 250).toLongLong();
   fadeout_pause_duration_nanosec_ = (fadeout_pause_duration_ * kNsecPerMsec);
 
+  bs2b_enabled_ = s.value("bs2b", false).toBool();
+
   s.endGroup();
 
   s.beginGroup(NetworkProxySettingsPage::kSettingsGroup);

src/engine/enginebase.h

@@ -210,6 +210,9 @@ class Base : public QObject {
   bool channels_enabled_;
   int channels_;
 
+  // Options
+  bool bs2b_enabled_;
+
  private:
   bool about_to_end_emitted_;
   Q_DISABLE_COPY(Base)

src/engine/gstengine.cpp

@@ -801,6 +801,7 @@ std::shared_ptr<GstEnginePipeline> GstEngine::CreatePipeline() {
   ret->set_buffer_high_watermark(buffer_high_watermark_);
   ret->set_proxy_settings(proxy_address_, proxy_authentication_, proxy_user_, proxy_pass_);
   ret->set_channels(channels_enabled_, channels_);
+  ret->set_bs2b_enabled(bs2b_enabled_);
 
   ret->AddBufferConsumer(this);
   for (GstBufferConsumer *consumer : buffer_consumers_) {

src/engine/gstenginepipeline.cpp

@@ -86,6 +86,7 @@ GstEnginePipeline::GstEnginePipeline(QObject *parent)
       proxy_authentication_(false),
       channels_enabled_(false),
       channels_(0),
+      bs2b_enabled_(false),
       segment_start_(0),
       segment_start_received_(false),
       end_offset_nanosec_(-1),
@@ -216,6 +217,10 @@ void GstEnginePipeline::set_channels(const bool enabled, const int channels) {
   channels_ = channels;
 }
 
+void GstEnginePipeline::set_bs2b_enabled(const bool enabled) {
+  bs2b_enabled_ = enabled;
+}
+
 GstElement *GstEnginePipeline::CreateElement(const QString &factory_name, const QString &name, GstElement *bin, QString &error) const {
 
   QString unique_name = QString("pipeline") + "-" + QString::number(id_) + "-" + (name.isEmpty() ? factory_name : name);
@@ -515,6 +520,16 @@ bool GstEnginePipeline::InitAudioBin(QString &error) {
     g_object_set(G_OBJECT(rglimiter), "enabled", static_cast<int>(rg_compression_), nullptr);
   }
 
+  GstElement *bs2b = nullptr;
+  if (bs2b_enabled_) {
+    bs2b = CreateElement("bs2b", "bs2b", audiobin_, error);
+    if (!bs2b) {
+      gst_object_unref(GST_OBJECT(audiobin_));
+      audiobin_ = nullptr;
+      return false;
+    }
+  }
+
   {  // Create a pad on the outside of the audiobin and connect it to the pad of the first element.
     GstPad *pad = gst_element_get_static_pad(audioqueue_, "sink");
     if (pad) {
@@ -595,6 +610,18 @@ bool GstEnginePipeline::InitAudioBin(QString &error) {
     next = volume_;
   }
 
+  // Link bs2b element if enabled.
+  if (bs2b_enabled_ && bs2b) {
+    qLog(Debug) << "Enabling bs2b";
+    if (!gst_element_link(next, bs2b)) {
+      gst_object_unref(GST_OBJECT(audiobin_));
+      audiobin_ = nullptr;
+      error = "gst_element_link() failed.";
+      return false;
+    }
+    next = bs2b;
+  }
+
   if (!gst_element_link(next, audioconverter)) {
     gst_object_unref(GST_OBJECT(audiobin_));
     audiobin_ = nullptr;

src/engine/gstenginepipeline.h

@@ -73,6 +73,7 @@ class GstEnginePipeline : public QObject {
   void set_buffer_high_watermark(const double value);
   void set_proxy_settings(const QString &address, const bool authentication, const QString &user, const QString &pass);
   void set_channels(const bool enabled, const int channels);
+  void set_bs2b_enabled(const bool enabled);
 
   // Creates the pipeline, returns false on error
   bool InitFromUrl(const QByteArray &stream_url, const QUrl &original_url, const qint64 end_nanosec, QString &error);
@@ -221,6 +222,9 @@ class GstEnginePipeline : public QObject {
   bool channels_enabled_;
   int channels_;
 
+  // Options
+  bool bs2b_enabled_;
+
   // These get called when there is a new audio buffer available
   QList<GstBufferConsumer*> buffer_consumers_;
   QMutex buffer_consumers_mutex_;

src/settings/backendsettingspage.cpp

@@ -164,6 +164,8 @@ void BackendSettingsPage::Load() {
   ui_->spinbox_channels->setValue(s.value("channels", 2).toInt());
   ui_->widget_channels->setEnabled(ui_->checkbox_channels->isChecked());
 
+  ui_->checkbox_bs2b->setChecked(s.value("bs2b", false).toBool());
+
   ui_->spinbox_bufferduration->setValue(s.value("bufferduration", kDefaultBufferDuration).toInt());
   ui_->spinbox_low_watermark->setValue(s.value("bufferlowwatermark", kDefaultBufferLowWatermark).toDouble());
   ui_->spinbox_high_watermark->setValue(s.value("bufferhighwatermark", kDefaultBufferHighWatermark).toDouble());
@@ -460,6 +462,20 @@ void BackendSettingsPage::Save() {
   s.setValue("output", output_name);
   s.setValue("device", device_value);
 
+#ifdef HAVE_ALSA
+  if (ui_->radiobutton_alsa_hw->isChecked()) s.setValue("alsaplugin", static_cast<int>(alsa_plugin::alsa_hw));
+  else if (ui_->radiobutton_alsa_plughw->isChecked()) s.setValue("alsaplugin", static_cast<int>(alsa_plugin::alsa_plughw));
+  else if (ui_->radiobutton_alsa_pcm->isChecked()) s.setValue("alsaplugin", static_cast<int>(alsa_plugin::alsa_pcm));
+  else s.remove("alsaplugin");
+#endif
+
+  s.setValue("volume_control", ui_->checkbox_volume_control->isChecked());
+
+  s.setValue("channels_enabled", ui_->checkbox_channels->isChecked());
+  s.setValue("channels", ui_->spinbox_channels->value());
+
+  s.setValue("bs2b", ui_->checkbox_bs2b->isChecked());
+
   s.setValue("bufferduration", ui_->spinbox_bufferduration->value());
   s.setValue("bufferlowwatermark", ui_->spinbox_low_watermark->value());
   s.setValue("bufferhighwatermark", ui_->spinbox_high_watermark->value());
@@ -478,18 +494,6 @@ void BackendSettingsPage::Save() {
   s.setValue("FadeoutDuration", ui_->spinbox_fadeduration->value());
   s.setValue("FadeoutPauseDuration", ui_->spinbox_fadeduration_pauseresume->value());
 
-#ifdef HAVE_ALSA
-  if (ui_->radiobutton_alsa_hw->isChecked()) s.setValue("alsaplugin", static_cast<int>(alsa_plugin::alsa_hw));
-  else if (ui_->radiobutton_alsa_plughw->isChecked()) s.setValue("alsaplugin", static_cast<int>(alsa_plugin::alsa_plughw));
-  else if (ui_->radiobutton_alsa_pcm->isChecked()) s.setValue("alsaplugin", static_cast<int>(alsa_plugin::alsa_pcm));
-  else s.remove("alsaplugin");
-#endif
-
-  s.setValue("volume_control", ui_->checkbox_volume_control->isChecked());
-
-  s.setValue("channels_enabled", ui_->checkbox_channels->isChecked());
-  s.setValue("channels", ui_->spinbox_channels->value());
-
   s.endGroup();
 
 }

src/settings/backendsettingspage.ui

@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>583</width>
-    <height>880</height>
+    <height>1080</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -153,6 +153,15 @@
         </layout>
        </widget>
       </item>
+     </layout>
+    </widget>
+   </item>
+   <item>
+    <widget class="QGroupBox" name="groupBox">
+     <property name="title">
+      <string>Options</string>
+     </property>
+     <layout class="QVBoxLayout" name="verticalLayout_2">
       <item>
        <widget class="QCheckBox" name="checkbox_volume_control">
         <property name="text">
@@ -236,6 +245,13 @@
         </layout>
        </widget>
       </item>
+      <item>
+       <widget class="QCheckBox" name="checkbox_bs2b">
+        <property name="text">
+         <string>Improve headphone listening of stereo audio records (bs2b)</string>
+        </property>
+       </widget>
+      </item>
      </layout>
     </widget>
    </item>
@@ -699,7 +715,6 @@
   <tabstop>radiobutton_alsa_hw</tabstop>
   <tabstop>radiobutton_alsa_plughw</tabstop>
   <tabstop>radiobutton_alsa_pcm</tabstop>
-  <tabstop>checkbox_volume_control</tabstop>
   <tabstop>checkbox_channels</tabstop>
   <tabstop>spinbox_channels</tabstop>
   <tabstop>spinbox_bufferduration</tabstop>