Use system volume when possible

Fixes #1037

src/core/mainwindow.cpp

@@ -400,7 +400,7 @@ MainWindow::MainWindow(Application *app, std::shared_ptr<SystemTrayIcon> tray_ic
   app_->player()->Init();
   EngineChanged(app_->player()->engine()->type());
   const uint volume = app_->player()->GetVolume();
-  ui_->volume->SetValueFromVolume(volume);
+  ui_->volume->SetValue(volume);
   VolumeChanged(volume);
 
   // Models
@@ -583,7 +583,7 @@ MainWindow::MainWindow(Application *app, std::shared_ptr<SystemTrayIcon> tray_ic
   ui_->stop_button->setMenu(stop_menu);
 
   // Player connections
-  QObject::connect(ui_->volume, &VolumeSlider::valueChanged, app_->player(), &Player::SetVolumeFromValue);
+  QObject::connect(ui_->volume, &VolumeSlider::valueChanged, app_->player(), &Player::SetVolumeFromSlider);
 
   QObject::connect(app_->player(), &Player::EngineChanged, this, &MainWindow::EngineChanged);
   QObject::connect(app_->player(), &Player::Error, this, &MainWindow::ShowErrorDialog);
@@ -606,7 +606,7 @@ MainWindow::MainWindow(Application *app, std::shared_ptr<SystemTrayIcon> tray_ic
   QObject::connect(app_->player(), &Player::Stopped, osd_, &OSDBase::Stopped);
   QObject::connect(app_->player(), &Player::PlaylistFinished, osd_, &OSDBase::PlaylistFinished);
   QObject::connect(app_->player(), &Player::VolumeChanged, osd_, &OSDBase::VolumeChanged);
-  QObject::connect(app_->player(), &Player::VolumeChanged, ui_->volume, &VolumeSlider::SetValueFromVolume);
+  QObject::connect(app_->player(), &Player::VolumeChanged, ui_->volume, &VolumeSlider::SetValue);
   QObject::connect(app_->player(), &Player::ForceShowOSD, this, &MainWindow::ForceShowOSD);
 
   QObject::connect(app_->playlist_manager(), &PlaylistManager::CurrentSongChanged, this, &MainWindow::SongChanged);
@@ -1201,6 +1201,7 @@ void MainWindow::SaveSettings() {
 
   SaveGeometry();
   SavePlaybackStatus();
+  app_->player()->SaveVolume();
   ui_->tabs->SaveSettings(kSettingsGroup);
   ui_->playlist->view()->SaveSettings();
   app_->scrobbler()->WriteCache();

src/core/mpris2.cpp

@@ -22,6 +22,7 @@
 #include "config.h"
 
 #include <algorithm>
+#include <cmath>
 
 #include <QApplication>
 #include <QCoreApplication>
@@ -175,7 +176,9 @@ void Mpris2::EngineStateChanged(Engine::State newState) {
 
 }
 
-void Mpris2::VolumeChanged() { EmitNotification("Volume"); }
+void Mpris2::VolumeChanged() {
+  EmitNotification("Volume");
+}
 
 void Mpris2::ShuffleModeChanged() { EmitNotification("Shuffle"); }
 
@@ -411,8 +414,8 @@ double Mpris2::Volume() const {
   return app_->player()->GetVolume() / 100.0;
 }
 
-void Mpris2::SetVolume(const double value) {
-  app_->player()->SetVolume(static_cast<uint>(std::max(std::min(lround(value * 100.0), 100L), 0L)));
+void Mpris2::SetVolume(const double volume) {
+  app_->player()->SetVolume(static_cast<uint>(qBound(0L, lround(volume * 100.0), 100L)));
 }
 
 qint64 Mpris2::Position() const {

src/core/mpris2.h

@@ -145,7 +145,7 @@ class Mpris2 : public QObject {
   void SetShuffle(bool enable);
   QVariantMap Metadata() const;
   double Volume() const;
-  void SetVolume(const double value);
+  void SetVolume(const double volume);
   qint64 Position() const;
   double MaximumRate() const;
   double MinimumRate() const;

src/core/player.cpp

@@ -83,29 +83,24 @@ Player::Player(Application *app, QObject *parent)
       autoscroll_(Playlist::AutoScroll_Maybe),
       last_state_(Engine::Empty),
       nb_errors_received_(0),
+      volume_(100),
       volume_before_mute_(100),
       last_pressed_previous_(QDateTime::currentDateTime()),
       continue_on_error_(false),
       greyout_(true),
       menu_previousmode_(BehaviourSettingsPage::PreviousBehaviour_DontRestart),
       seek_step_sec_(10),
-      volume_control_(true),
       play_offset_nanosec_(0) {
 
-  settings_.beginGroup(kSettingsGroup);
-
   QSettings s;
   s.beginGroup(BackendSettingsPage::kSettingsGroup);
   Engine::EngineType enginetype = Engine::EngineTypeFromName(s.value("engine", EngineName(Engine::GStreamer)).toString().toLower());
   s.endGroup();
+
   CreateEngine(enginetype);
 
 }
 
-Player::~Player() {
-  settings_.endGroup();
-}
-
 Engine::EngineType Player::CreateEngine(Engine::EngineType enginetype) {
 
   Engine::EngineType use_enginetype(Engine::None);
@@ -181,6 +176,7 @@ void Player::Init() {
   QObject::connect(engine_.get(), &EngineBase::TrackAboutToEnd, this, &Player::TrackAboutToEnd);
   QObject::connect(engine_.get(), &EngineBase::TrackEnded, this, &Player::TrackEnded);
   QObject::connect(engine_.get(), &EngineBase::MetaData, this, &Player::EngineMetadataReceived);
+  QObject::connect(engine_.get(), &EngineBase::VolumeChanged, this, &Player::SetVolumeFromEngine);
 
   // Equalizer
   QObject::connect(equalizer_, &Equalizer::StereoBalancerEnabledChanged, app_->player()->engine(), &EngineBase::SetStereoBalancerEnabled);
@@ -193,17 +189,10 @@ void Player::Init() {
   engine_->SetEqualizerEnabled(equalizer_->is_equalizer_enabled());
   engine_->SetEqualizerParameters(equalizer_->preamp_value(), equalizer_->gain_values());
 
-  s.beginGroup(BackendSettingsPage::kSettingsGroup);
-  volume_control_ = s.value("volume_control", true).toBool();
-  s.endGroup();
-
-  if (volume_control_) {
-    int volume = settings_.value("volume", 100).toInt();
-    SetVolume(volume);
-  }
-
   ReloadSettings();
 
+  LoadVolume();
+
 }
 
 void Player::ReloadSettings() {
@@ -220,15 +209,30 @@ void Player::ReloadSettings() {
   seek_step_sec_ = s.value("seek_step_sec", 10).toInt();
   s.endGroup();
 
-  s.beginGroup(BackendSettingsPage::kSettingsGroup);
-  bool volume_control = s.value("volume_control", true).toBool();
-  if (!volume_control && GetVolume() != 100) SetVolume(100);
-  s.endGroup();
-
   engine_->ReloadSettings();
 
 }
 
+void Player::LoadVolume() {
+
+  QSettings s;
+  s.beginGroup(kSettingsGroup);
+  const uint volume = s.value("volume", 100).toInt();
+  s.endGroup();
+
+  SetVolume(volume);
+
+}
+
+void Player::SaveVolume() {
+
+  QSettings s;
+  s.beginGroup(kSettingsGroup);
+  s.setValue("volume", volume_);
+  s.endGroup();
+  
+}
+
 void Player::HandleLoadResult(const UrlHandler::LoadResult &result) {
 
   if (loading_async_.contains(result.original_url_)) {
@@ -641,23 +645,35 @@ uint Player::GetVolume() const {
 
 }
 
-void Player::SetVolumeFromValue(const int value) {
+void Player::SetVolumeFromSlider(const int value) {
 
-  SetVolume(static_cast<uint>(std::max(0, value)));
+  const uint volume = static_cast<uint>(qBound(0, value, 100));
+  if (volume != volume_) {
+    engine_->SetVolume(volume);
+    emit VolumeChanged(volume_);
+  }
+
+}
+
+void Player::SetVolumeFromEngine(const uint volume) {
+
+  const uint new_volume = qBound(0U, volume, 100U);
+  if (new_volume != volume_) {
+    volume_ = new_volume;
+    emit VolumeChanged(volume_);
+  }
 
 }
 
 void Player::SetVolume(const uint volume) {
 
-  uint old_volume = engine_->volume();
-  uint new_volume = qBound(0U, volume, 100U);
-  settings_.setValue("volume", new_volume);
-  engine_->SetVolume(new_volume);
-
-  if (new_volume != old_volume) {
-    emit VolumeChanged(new_volume);
+  const uint new_volume = qBound(0U, volume, 100U);
+  if (new_volume != volume_) {
+    engine_->SetVolume(volume);
+    volume_ = new_volume;
+    emit VolumeChanged(volume_);
   }
-
+  
 }
 
 void Player::VolumeUp() {
@@ -794,8 +810,6 @@ PlaylistItemPtr Player::GetItemAt(const int pos) const {
 
 void Player::Mute() {
 
-  if (!volume_control_) return;
-
   const uint current_volume = engine_->volume();
 
   if (current_volume == 0) {

src/core/player.h

@@ -32,7 +32,6 @@
 #include <QDateTime>
 #include <QString>
 #include <QUrl>
-#include <QSettings>
 
 #include "urlhandler.h"
 #include "engine/engine_fwd.h"
@@ -71,6 +70,8 @@ class PlayerInterface : public QObject {
 
  public slots:
   virtual void ReloadSettings() = 0;
+  virtual void LoadVolume() = 0;
+  virtual void SaveVolume() = 0;
 
   // Manual track change to the specified track
   virtual void PlayAt(const int index, const quint64 offset_nanosec, Engine::TrackChangeFlags change, const Playlist::AutoScroll autoscroll, const bool reshuffle, const bool force_inform = false) = 0;
@@ -84,7 +85,8 @@ class PlayerInterface : public QObject {
   virtual void Next() = 0;
   virtual void Previous() = 0;
   virtual void PlayPlaylist(const QString &playlist_name) = 0;
-  virtual void SetVolumeFromValue(const int value) = 0;
+  virtual void SetVolumeFromEngine(const uint volume) = 0;
+  virtual void SetVolumeFromSlider(const int value) = 0;
   virtual void SetVolume(const uint volume) = 0;
   virtual void VolumeUp() = 0;
   virtual void VolumeDown() = 0;
@@ -133,7 +135,6 @@ class Player : public PlayerInterface {
 
  public:
   explicit Player(Application *app, QObject *parent);
-  ~Player() override;
 
   static const char *kSettingsGroup;
 
@@ -159,6 +160,8 @@ class Player : public PlayerInterface {
 
  public slots:
   void ReloadSettings() override;
+  void LoadVolume() override;
+  void SaveVolume() override;
 
   void PlayAt(const int index, const quint64 offset_nanosec, Engine::TrackChangeFlags change, const Playlist::AutoScroll autoscroll, const bool reshuffle, const bool force_inform = false) override;
   void PlayPause(const quint64 offset_nanosec = 0, const Playlist::AutoScroll autoscroll = Playlist::AutoScroll_Always) override;
@@ -167,8 +170,9 @@ class Player : public PlayerInterface {
   void Next() override;
   void Previous() override;
   void PlayPlaylist(const QString &playlist_name) override;
-  void SetVolumeFromValue(const int value) override;
-  void SetVolume(const uint value) override;
+  void SetVolumeFromSlider(const int value) override;
+  void SetVolumeFromEngine(const uint volume) override;
+  void SetVolume(const uint volume) override;
   void VolumeUp() override;
   void VolumeDown() override;
   void SeekTo(const quint64 seconds) override;
@@ -225,8 +229,6 @@ class Player : public PlayerInterface {
   AnalyzerContainer *analyzer_;
   Equalizer *equalizer_;
 
-  QSettings settings_;
-
   PlaylistItemPtr current_item_;
 
   Engine::TrackChangeFlags stream_change_type_;
@@ -237,6 +239,7 @@ class Player : public PlayerInterface {
   QMap<QString, UrlHandler*> url_handlers_;
 
   QList<QUrl> loading_async_;
+  uint volume_;
   uint volume_before_mute_;
   QDateTime last_pressed_previous_;
 
@@ -245,8 +248,6 @@ class Player : public PlayerInterface {
   BehaviourSettingsPage::PreviousBehaviour menu_previousmode_;
   int seek_step_sec_;
 
-  bool volume_control_;
-
   QDateTime pause_time_;
   quint64 play_offset_nanosec_;
 

src/engine/enginebase.cpp

@@ -99,16 +99,18 @@ bool Engine::Base::Play(const QUrl &stream_url, const QUrl &original_url, const
 
 }
 
-void Engine::Base::SetVolume(const uint value) {
+void Engine::Base::UpdateVolume(const uint volume) {
 
-  volume_ = value;
-  SetVolumeSW(MakeVolumeLogarithmic(value));
+  volume_ = volume;
+  emit VolumeChanged(volume);
 
 }
 
-uint Engine::Base::MakeVolumeLogarithmic(const uint volume) {
-  // We're using a logarithmic function to make the volume ramp more natural.
-  return static_cast<uint>(100 - 100.0 * std::log10((100 - volume) * 0.09 + 1.0));
+void Engine::Base::SetVolume(const uint volume) {
+
+  volume_ = volume;
+  SetVolumeSW(volume);
+
 }
 
 void Engine::Base::ReloadSettings() {

src/engine/enginebase.h

@@ -97,11 +97,11 @@ class Base : public QObject {
   // Plays a media stream represented with the URL 'u' from the given 'beginning' to the given 'end' (usually from 0 to a song's length).
   // Both markers should be passed in nanoseconds. 'end' can be negative, indicating that the real length of 'u' stream is unknown.
   bool Play(const QUrl &stream_url, const QUrl &original_url, const TrackChangeFlags flags, const bool force_stop_at_end, const quint64 beginning_nanosec, const qint64 end_nanosec, const quint64 offset_nanosec);
-  void SetVolume(const uint value);
-  static uint MakeVolumeLogarithmic(const uint volume);
+  void SetVolume(const uint volume);
 
  public slots:
   virtual void ReloadSettings();
+  void UpdateVolume(const uint volume);
 
  protected:
   void EmitAboutToEnd();
@@ -153,6 +153,8 @@ class Base : public QObject {
   // Always use the state from event, because it's not guaranteed that immediate subsequent call to state() won't return a stale value.
   void StateChanged(Engine::State);
 
+  void VolumeChanged(uint volume);
+
  protected:
 
   struct PluginDetails {

src/engine/gstengine.cpp

@@ -340,8 +340,8 @@ void GstEngine::Seek(const quint64 offset_nanosec) {
   }
 }
 
-void GstEngine::SetVolumeSW(const uint percent) {
-  if (current_pipeline_) current_pipeline_->SetVolume(percent);
+void GstEngine::SetVolumeSW(const uint volume) {
+  if (current_pipeline_) current_pipeline_->SetVolume(volume);
 }
 
 qint64 GstEngine::position_nanosec() const {
@@ -802,6 +802,7 @@ std::shared_ptr<GstEnginePipeline> GstEngine::CreatePipeline() {
   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->set_fading_enabled(fadeout_enabled_ || autocrossfade_enabled_ || fadeout_pause_enabled_);
 
   ret->AddBufferConsumer(this);
   for (GstBufferConsumer *consumer : buffer_consumers_) {
@@ -814,6 +815,7 @@ std::shared_ptr<GstEnginePipeline> GstEngine::CreatePipeline() {
   QObject::connect(ret.get(), &GstEnginePipeline::BufferingStarted, this, &GstEngine::BufferingStarted);
   QObject::connect(ret.get(), &GstEnginePipeline::BufferingProgress, this, &GstEngine::BufferingProgress);
   QObject::connect(ret.get(), &GstEnginePipeline::BufferingFinished, this, &GstEngine::BufferingFinished);
+  QObject::connect(ret.get(), &GstEnginePipeline::VolumeChanged, this, &EngineBase::UpdateVolume);
 
   return ret;
 

src/engine/gstengine.h

@@ -72,7 +72,7 @@ class GstEngine : public Engine::Base, public GstBufferConsumer {
   void Seek(const quint64 offset_nanosec) override;
 
  protected:
-  void SetVolumeSW(const uint percent) override;
+  void SetVolumeSW(const uint volume) override;
 
  public:
   qint64 position_nanosec() const override;

src/engine/gstenginepipeline.cpp

@@ -24,6 +24,7 @@
 #include <memory>
 #include <cstdint>
 #include <cstring>
+#include <cmath>
 #include <glib.h>
 #include <glib-object.h>
 #include <gst/gst.h>
@@ -70,6 +71,7 @@ GstEnginePipeline::GstEnginePipeline(QObject *parent)
       stereo_balancer_enabled_(false),
       eq_enabled_(false),
       rg_enabled_(false),
+      fading_enabled_(false),
       stereo_balance_(0.0F),
       eq_preamp_(0),
       rg_mode_(0),
@@ -97,18 +99,19 @@ GstEnginePipeline::GstEnginePipeline(QObject *parent)
       last_known_position_ns_(0),
       next_uri_set_(false),
       volume_percent_(100),
-      volume_modifier_(1.0F),
       use_fudge_timer_(false),
       pipeline_(nullptr),
       audiobin_(nullptr),
       audioqueue_(nullptr),
       volume_(nullptr),
+      volume_fading_(nullptr),
       audiopanorama_(nullptr),
       equalizer_(nullptr),
       equalizer_preamp_(nullptr),
       pad_added_cb_id_(-1),
       notify_source_cb_id_(-1),
       about_to_finish_cb_id_(-1),
+      notify_volume_cb_id_(-1),
       logged_unsupported_analyzer_format_(false) {
 
   eq_band_gains_.reserve(kEqBandCount);
@@ -139,6 +142,10 @@ GstEnginePipeline::~GstEnginePipeline() {
       g_signal_handler_disconnect(G_OBJECT(pipeline_), about_to_finish_cb_id_);
     }
 
+    if (notify_volume_cb_id_ != -1) {
+      g_signal_handler_disconnect(G_OBJECT(volume_), notify_volume_cb_id_);
+    }
+
     GstBus *bus = gst_pipeline_get_bus(GST_PIPELINE(pipeline_));
     if (bus) {
       gst_bus_remove_watch(bus);
@@ -218,6 +225,10 @@ void GstEnginePipeline::set_bs2b_enabled(const bool enabled) {
   bs2b_enabled_ = enabled;
 }
 
+void GstEnginePipeline::set_fading_enabled(const bool enabled) {
+  fading_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);
@@ -249,6 +260,10 @@ bool GstEnginePipeline::InitFromUrl(const QByteArray &stream_url, const QUrl &or
 
   if (!InitAudioBin(error)) return false;
 
+  if (volume_) {
+    notify_volume_cb_id_ = CHECKED_GCONNECT(G_OBJECT(volume_), "notify::volume", &VolumeCallback, this);
+  }
+
   // Set playbin's sink to be our custom audio-sink.
   g_object_set(GST_OBJECT(pipeline_), "audio-sink", audiobin_, nullptr);
 
@@ -256,14 +271,9 @@ bool GstEnginePipeline::InitFromUrl(const QByteArray &stream_url, const QUrl &or
   g_object_get(G_OBJECT(pipeline_), "flags", &flags, nullptr);
   flags |= 0x00000002;
   flags &= ~0x00000001;
-  if (volume_enabled_) {
-    flags |= 0x00000010;
-  }
-  else {
-    flags &= ~0x00000010;
-  }
-
+  flags &= ~0x00000010;
   g_object_set(G_OBJECT(pipeline_), "flags", flags, nullptr);
+
   g_object_set(G_OBJECT(pipeline_), "uri", stream_url.constData(), nullptr);
 
   pipeline_is_connected_ = true;
@@ -394,6 +404,11 @@ bool GstEnginePipeline::InitAudioBin(QString &error) {
 
   }
 
+  if (g_object_class_find_property(G_OBJECT_GET_CLASS(audiosink), "volume")) {
+    qLog(Debug) << output_ << "has volume element, enabling system volume synchronization.";
+    volume_ = audiosink;
+  }
+
   // Create all the other elements
 
   audioqueue_ = CreateElement("queue2", "audioqueue", audiobin_, error);
@@ -411,9 +426,20 @@ bool GstEnginePipeline::InitAudioBin(QString &error) {
   }
 
   // Create the volume elements if it's enabled.
-  if (volume_enabled_) {
-    volume_ = CreateElement("volume", "volume", audiobin_, error);
-    if (!volume_) {
+  GstElement *swvolume = nullptr;
+  if (volume_enabled_ && !volume_) {
+    swvolume = CreateElement("volume", "volume_sw", audiobin_, error);
+    if (!swvolume) {
+      gst_object_unref(GST_OBJECT(audiobin_));
+      audiobin_ = nullptr;
+      return false;
+    }
+    volume_ = swvolume;
+  }
+
+  if (fading_enabled_) {
+    volume_fading_ = CreateElement("volume", "volume_fading", audiobin_, error);
+    if (!volume_fading_) {
       gst_object_unref(GST_OBJECT(audiobin_));
       audiobin_ = nullptr;
       return false;
@@ -561,69 +587,80 @@ bool GstEnginePipeline::InitAudioBin(QString &error) {
 
   // Link all elements
 
-  GstElement *next = audioqueue_;  // The next element to link from.
+  if (!gst_element_link(audioqueue_, audioconverter)) {
+    gst_object_unref(GST_OBJECT(audiobin_));
+    audiobin_ = nullptr;
+    error = "gst_element_link() failed.";
+    return false;
+  }
+
+  GstElement *element_link = audioconverter;  // The next element to link from.
 
   // Link replaygain elements if enabled.
   if (rg_enabled_ && rgvolume && rglimiter && rgconverter) {
-    if (!gst_element_link_many(next, rgvolume, rglimiter, rgconverter, nullptr)) {
+    if (!gst_element_link_many(element_link, rgvolume, rglimiter, rgconverter, nullptr)) {
       gst_object_unref(GST_OBJECT(audiobin_));
       audiobin_ = nullptr;
       error = "gst_element_link_many() failed.";
       return false;
     }
-    next = rgconverter;
+    element_link = rgconverter;
   }
 
   // Link equalizer elements if enabled.
   if (eq_enabled_ && equalizer_ && equalizer_preamp_) {
-    if (!gst_element_link_many(next, equalizer_preamp_, equalizer_, nullptr)) {
+    if (!gst_element_link_many(element_link, equalizer_preamp_, equalizer_, nullptr)) {
       gst_object_unref(GST_OBJECT(audiobin_));
       audiobin_ = nullptr;
       error = "gst_element_link_many() failed.";
       return false;
     }
-    next = equalizer_;
+    element_link = equalizer_;
   }
 
   // Link stereo balancer elements if enabled.
   if (stereo_balancer_enabled_ && audiopanorama_) {
-    if (!gst_element_link(next, audiopanorama_)) {
+    if (!gst_element_link(element_link, audiopanorama_)) {
       gst_object_unref(GST_OBJECT(audiobin_));
       audiobin_ = nullptr;
       error = "gst_element_link() failed.";
       return false;
     }
-    next = audiopanorama_;
+    element_link = audiopanorama_;
   }
 
-  // Link volume elements if enabled.
-  if (volume_enabled_ && volume_) {
-    if (!gst_element_link(next, volume_)) {
+  // Link software volume element if enabled.
+  if (volume_enabled_ && swvolume) {
+    if (!gst_element_link(element_link, swvolume)) {
       gst_object_unref(GST_OBJECT(audiobin_));
       audiobin_ = nullptr;
       error = "gst_element_link() failed.";
       return false;
     }
-    next = volume_;
+    element_link = swvolume;
+  }
+
+  // Link fading volume element if enabled.
+  if (fading_enabled_ && volume_fading_) {
+    if (!gst_element_link(element_link, volume_fading_)) {
+      gst_object_unref(GST_OBJECT(audiobin_));
+      audiobin_ = nullptr;
+      error = "gst_element_link() failed.";
+      return false;
+    }
+    element_link = volume_fading_;
   }
 
   // Link bs2b element if enabled.
   if (bs2b_enabled_ && bs2b) {
     qLog(Debug) << "Enabling bs2b";
-    if (!gst_element_link(next, bs2b)) {
+    if (!gst_element_link(element_link, 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;
-    error = "gst_element_link() failed.";
-    return false;
+    element_link = bs2b;
   }
 
   {
@@ -638,12 +675,12 @@ bool GstEnginePipeline::InitAudioBin(QString &error) {
       qLog(Debug) << "Setting channels to" << channels_;
       gst_caps_set_simple(caps, "channels", G_TYPE_INT, channels_, nullptr);
     }
-    gst_element_link_filtered(audioconverter, audiosink, caps);
+    gst_element_link_filtered(element_link, audiosink, caps);
     gst_caps_unref(caps);
   }
 
   {  // Add probes and handlers.
-    GstPad *pad = gst_element_get_static_pad(audioqueue_, "src");
+    GstPad *pad = gst_element_get_static_pad(audioconverter, "src");
     if (pad) {
       gst_pad_add_probe(pad, GST_PAD_PROBE_TYPE_BUFFER, HandoffCallback, this, nullptr);
       gst_object_unref(pad);
@@ -738,6 +775,21 @@ void GstEnginePipeline::SourceSetupCallback(GstPlayBin *bin, GParamSpec*, gpoint
 
 }
 
+void GstEnginePipeline::VolumeCallback(GstElement*, GParamSpec*, gpointer self) {
+
+  GstEnginePipeline *instance = reinterpret_cast<GstEnginePipeline*>(self);
+
+  gdouble volume = 0;
+  g_object_get(G_OBJECT(instance->volume_), "volume", &volume, nullptr);
+
+  const uint volume_percent = static_cast<uint>(qBound(0L, lround(qBound(0.0, gst_stream_volume_convert_volume(GST_STREAM_VOLUME_FORMAT_LINEAR, GST_STREAM_VOLUME_FORMAT_CUBIC, volume), 1.0) / 0.01), 100L));
+  if (volume_percent != instance->volume_percent_) {
+    instance->volume_percent_ = volume_percent;
+    emit instance->VolumeChanged(volume_percent);
+  }
+
+}
+
 void GstEnginePipeline::NewPadCallback(GstElement*, GstPad *pad, gpointer self) {
 
   GstEnginePipeline *instance = reinterpret_cast<GstEnginePipeline*>(self);
@@ -1355,27 +1407,22 @@ bool GstEnginePipeline::Seek(const qint64 nanosec) {
 
 }
 
-void GstEnginePipeline::SetVolume(const uint percent) {
+void GstEnginePipeline::SetVolume(const uint volume_percent) {
 
-  if (!volume_) return;
-  volume_percent_ = percent;
-  UpdateVolume();
+  if (volume_) {
+    const double volume = gst_stream_volume_convert_volume(GST_STREAM_VOLUME_FORMAT_CUBIC, GST_STREAM_VOLUME_FORMAT_LINEAR, static_cast<double>(volume_percent) * 0.01);
+    g_object_set(G_OBJECT(volume_), "volume", volume, nullptr);
+  }
+
+  volume_percent_ = volume_percent;
 
 }
 
-void GstEnginePipeline::SetVolumeModifier(const qreal mod) {
+void GstEnginePipeline::SetFaderVolume(const qreal volume) {
 
-  if (!volume_) return;
-  volume_modifier_ = mod;
-  UpdateVolume();
-
-}
-
-void GstEnginePipeline::UpdateVolume() {
-
-  if (!volume_) return;
-  double vol = static_cast<double>(volume_percent_) * static_cast<double>(0.01) * volume_modifier_;
-  g_object_set(G_OBJECT(volume_), "volume", vol, nullptr);
+  if (volume_fading_) {
+    g_object_set(G_OBJECT(volume_fading_), "volume", volume, nullptr);
+  }
 
 }
 
@@ -1454,7 +1501,7 @@ void GstEnginePipeline::StartFader(const qint64 duration_nanosec, const QTimeLin
     }
     timeline->deleteLater();
   });
-  QObject::connect(fader_.get(), &QTimeLine::valueChanged, this, &GstEnginePipeline::SetVolumeModifier);
+  QObject::connect(fader_.get(), &QTimeLine::valueChanged, this, &GstEnginePipeline::SetFaderVolume);
   QObject::connect(fader_.get(), &QTimeLine::finished, this, &GstEnginePipeline::FaderTimelineFinished);
   fader_->setDirection(direction);
   fader_->setEasingCurve(shape);
@@ -1464,7 +1511,7 @@ void GstEnginePipeline::StartFader(const qint64 duration_nanosec, const QTimeLin
   fader_fudge_timer_.stop();
   use_fudge_timer_ = use_fudge_timer;
 
-  SetVolumeModifier(fader_->currentValue());
+  SetFaderVolume(fader_->currentValue());
 
 }
 

src/engine/gstenginepipeline.h

@@ -74,6 +74,7 @@ class GstEnginePipeline : public QObject {
   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);
+  void set_fading_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);
@@ -86,7 +87,7 @@ class GstEnginePipeline : public QObject {
   // Control the music playback
   QFuture<GstStateChangeReturn> SetState(const GstState state);
   Q_INVOKABLE bool Seek(const qint64 nanosec);
-  void SetVolume(const uint percent);
+  void SetVolume(const uint volume_percent);
   void SetStereoBalance(const float value);
   void SetEqualizerParams(const int preamp, const QList<int> &band_gains);
 
@@ -121,7 +122,7 @@ class GstEnginePipeline : public QObject {
   QString source_device() const { return source_device_; }
 
  public slots:
-  void SetVolumeModifier(qreal mod);
+  void SetFaderVolume(qreal mod);
 
  signals:
   void Error(int pipeline_id, int domain, int error_code, QString message, QString debug);
@@ -129,6 +130,7 @@ class GstEnginePipeline : public QObject {
   void EndOfStreamReached(int pipeline_id, bool has_next_track);
   void MetadataFound(int pipeline_id, const Engine::SimpleMetaBundle &bundle);
 
+  void VolumeChanged(uint volume);
   void FaderFinished();
 
   void BufferingStarted();
@@ -145,6 +147,7 @@ class GstEnginePipeline : public QObject {
   // Static callbacks.  The GstEnginePipeline instance is passed in the last argument.
   static GstPadProbeReturn EventHandoffCallback(GstPad*, GstPadProbeInfo*, gpointer);
   static void SourceSetupCallback(GstPlayBin*, GParamSpec *pspec, gpointer);
+  static void VolumeCallback(GstElement*, GParamSpec*, gpointer self);
   static void NewPadCallback(GstElement*, GstPad*, gpointer);
   static GstPadProbeReturn PlaybinProbe(GstPad*, GstPadProbeInfo*, gpointer);
   static GstPadProbeReturn HandoffCallback(GstPad*, GstPadProbeInfo*, gpointer);
@@ -164,7 +167,6 @@ class GstEnginePipeline : public QObject {
   static QString ParseStrTag(GstTagList *list, const char *tag);
   static guint ParseUIntTag(GstTagList *list, const char *tag);
 
-  void UpdateVolume();
   void UpdateStereoBalance();
   void UpdateEqualizer();
 
@@ -190,6 +192,7 @@ class GstEnginePipeline : public QObject {
   bool stereo_balancer_enabled_;
   bool eq_enabled_;
   bool rg_enabled_;
+  bool fading_enabled_;
 
   // Stereo balance:
   // From -1.0 - 1.0
@@ -271,7 +274,6 @@ class GstEnginePipeline : public QObject {
   bool next_uri_set_;
 
   uint volume_percent_;
-  qreal volume_modifier_;
 
   std::shared_ptr<QTimeLine> fader_;
   QBasicTimer fader_fudge_timer_;
@@ -281,6 +283,7 @@ class GstEnginePipeline : public QObject {
   GstElement *audiobin_;
   GstElement *audioqueue_;
   GstElement *volume_;
+  GstElement *volume_fading_;
   GstElement *audiopanorama_;
   GstElement *equalizer_;
   GstElement *equalizer_preamp_;
@@ -288,6 +291,7 @@ class GstEnginePipeline : public QObject {
   int pad_added_cb_id_;
   int notify_source_cb_id_;
   int about_to_finish_cb_id_;
+  int notify_volume_cb_id_;
 
   QThreadPool set_state_threadpool_;
 

src/settings/backendsettingspage.cpp

@@ -94,7 +94,6 @@ BackendSettingsPage::BackendSettingsPage(SettingsDialog *dialog, QWidget *parent
   QObject::connect(ui_->checkbox_fadeout_stop, &QCheckBox::toggled, this, &BackendSettingsPage::FadingOptionsChanged);
   QObject::connect(ui_->checkbox_fadeout_cross, &QCheckBox::toggled, this, &BackendSettingsPage::FadingOptionsChanged);
   QObject::connect(ui_->checkbox_fadeout_auto, &QCheckBox::toggled, this, &BackendSettingsPage::FadingOptionsChanged);
-  QObject::connect(ui_->checkbox_volume_control, &QCheckBox::toggled, this, &BackendSettingsPage::FadingOptionsChanged);
   QObject::connect(ui_->checkbox_channels, &QCheckBox::toggled, ui_->widget_channels, &QSpinBox::setEnabled);
   QObject::connect(ui_->button_buffer_defaults, &QPushButton::clicked, this, &BackendSettingsPage::BufferDefaults);
 
@@ -800,8 +799,7 @@ void BackendSettingsPage::FadingOptionsChanged() {
 
   EngineBase::OutputDetails output = ui_->combobox_output->itemData(ui_->combobox_output->currentIndex()).value<EngineBase::OutputDetails>();
   if (engine()->type() == Engine::GStreamer &&
-      !(engine()->ALSADeviceSupport(output.name) && !ui_->lineedit_device->text().isEmpty() && (ui_->lineedit_device->text().contains(QRegularExpression("^hw:.*")) || ui_->lineedit_device->text().contains(QRegularExpression("^plughw:.*")))) &&
-      ui_->checkbox_volume_control->isChecked()) {
+      !(engine()->ALSADeviceSupport(output.name) && !ui_->lineedit_device->text().isEmpty() && (ui_->lineedit_device->text().contains(QRegularExpression("^hw:.*")) || ui_->lineedit_device->text().contains(QRegularExpression("^plughw:.*"))))) {
     ui_->groupbox_fading->setEnabled(true);
   }
   else {

src/widgets/volumeslider.cpp

@@ -68,7 +68,7 @@ void SliderSlider::wheelEvent(QWheelEvent *e) {
 
   QSlider::setValue(nval);
 
-  emit sliderReleased(value());
+  emit SliderReleased(value());
 
 }
 
@@ -133,7 +133,7 @@ void SliderSlider::mousePressEvent(QMouseEvent *e) {
 void SliderSlider::mouseReleaseEvent(QMouseEvent*) {
 
   if (!outside_ && QSlider::value() != prev_value_) {
-    emit sliderReleased(value());
+    emit SliderReleased(value());
   }
 
   sliding_ = false;
@@ -141,7 +141,7 @@ void SliderSlider::mouseReleaseEvent(QMouseEvent*) {
 
 }
 
-void SliderSlider::SetValueFromVolume(const uint value) {
+void SliderSlider::SetValue(const uint value) {
 
   setValue(static_cast<int>(value));
 
@@ -298,21 +298,21 @@ void VolumeSlider::contextMenuEvent(QContextMenuEvent *e) {
 
   QAction *ret = menu.exec(mapToGlobal(e->pos()));
   if (ret) {
-    QSlider::setValue(values[ret]);  // clazy:exclude=skipped-base-method
-    emit sliderReleased(values[ret]);
+    QSlider::setValue(values[ret]);
+    emit SliderReleased(values[ret]);
   }
 
 }
 
 void VolumeSlider::slideEvent(QMouseEvent *e) {
-  QSlider::setValue(QStyle::sliderValueFromPosition(minimum(), maximum(), e->pos().x(), width() - 2));  // clazy:exclude=skipped-base-method
+  QSlider::setValue(QStyle::sliderValueFromPosition(minimum(), maximum(), e->pos().x(), width() - 2));
 }
 
 void VolumeSlider::wheelEvent(QWheelEvent *e) {
 
   const int step = e->angleDelta().y() / (e->angleDelta().x() == 0 ? 30 : -30);
-  QSlider::setValue(SliderSlider::value() + step);  // clazy:exclude=skipped-base-method
-  emit sliderReleased(value());
+  QSlider::setValue(SliderSlider::value() + step);
+  emit SliderReleased(value());
 
 }
 

src/widgets/volumeslider.h

@@ -44,15 +44,15 @@ class SliderSlider : public QSlider {
  public:
   explicit SliderSlider(const Qt::Orientation, QWidget*, const int max = 0);
 
-  virtual void SetValueFromVolume(const uint value);
+  virtual void SetValue(const uint value);
   virtual void setValue(int value);
 
   // WARNING non-virtual - and thus only really intended for internal use this is a major flaw in the class presently, however it suits our current needs fine
   int value() const { return adjustValue(QSlider::value()); }
 
  signals:
-  // we emit this when the user has specifically changed the slider so connect to it if valueChanged() is too generic Qt also emits valueChanged(int)
-  void sliderReleased(int);  // clazy:exclude=overloaded-signal
+  // We emit this when the user has specifically changed the slider so connect to it if valueChanged() is too generic Qt also emits valueChanged(int)
+  void SliderReleased(int);
 
  protected:
   void wheelEvent(QWheelEvent*) override;