Add stereo balance slider as part of equalizer.

src/engines/enginebase.h

@@ -101,6 +101,7 @@ class Base : public QObject, boost::noncopyable {
 
   virtual void SetEqualizerEnabled(bool) {}
   virtual void SetEqualizerParameters(int preamp, const QList<int>& bandGains) {}
+  virtual void SetStereoBalance(float value) {}
 
  signals:
   // Emitted when crossfading is enabled and the track is crossfade_duration_

src/engines/gstengine.cpp

@@ -77,6 +77,7 @@ GstEngine::GstEngine(TaskManager* task_manager)
     delayq_(g_queue_new()),
     current_sample_(0),
     equalizer_enabled_(false),
+    stereo_balance_(0.0f),
     rg_enabled_(false),
     rg_mode_(0),
     rg_preamp_(0.0),
@@ -351,6 +352,7 @@ bool GstEngine::Load(const QUrl& url, Engine::TrackChangeFlags change,
   SetVolume(volume_);
   SetEqualizerEnabled(equalizer_enabled_);
   SetEqualizerParameters(equalizer_preamp_, equalizer_gains_);
+  SetStereoBalance(stereo_balance_);
 
   // Maybe fade in this track
   if (crossfade)
@@ -581,6 +583,13 @@ void GstEngine::SetEqualizerParameters(int preamp, const QList<int>& band_gains)
     current_pipeline_->SetEqualizerParams(preamp, band_gains);
 }
 
+void GstEngine::SetStereoBalance(float value) {
+  stereo_balance_ = value;
+
+  if (current_pipeline_)
+    current_pipeline_->SetStereoBalance(value);
+}
+
 void GstEngine::SetVolumeSW( uint percent ) {
   if (current_pipeline_)
     current_pipeline_->SetVolume(percent);

src/engines/gstengine.h

@@ -105,6 +105,9 @@ class GstEngine : public Engine::Base, public BufferConsumer {
   /** Set equalizer preamp and gains, range -100..100. Gains are 10 values. */
   void SetEqualizerParameters(int preamp, const QList<int>& bandGains);
 
+  /** Set Stereo balance, range -1.0f..1.0f */
+  void SetStereoBalance(float value);
+
   void ReloadSettings();
 
   void AddBufferConsumer(BufferConsumer* consumer);
@@ -184,6 +187,7 @@ class GstEngine : public Engine::Base, public BufferConsumer {
   bool equalizer_enabled_;
   int equalizer_preamp_;
   QList<int> equalizer_gains_;
+  float stereo_balance_;
 
   bool rg_enabled_;
   int rg_mode_;

src/engines/gstenginepipeline.cpp

@@ -57,6 +57,7 @@ GstEnginePipeline::GstEnginePipeline(GstEngine* engine)
     emit_track_ended_on_segment_start_(false),
     eq_enabled_(false),
     eq_preamp_(0),
+    stereo_balance_(0.0f),
     rg_enabled_(false),
     rg_mode_(0),
     rg_preamp_(0.0),
@@ -84,6 +85,7 @@ GstEnginePipeline::GstEnginePipeline(GstEngine* engine)
     rglimiter_(NULL),
     audioconvert2_(NULL),
     equalizer_(NULL),
+    stereo_panorama_(NULL),
     volume_(NULL),
     audioscale_(NULL),
     audiosink_(NULL)
@@ -243,13 +245,14 @@ bool GstEnginePipeline::Init() {
   audio_queue       = engine_->CreateElement("queue",            audiobin_);
   equalizer_preamp_ = engine_->CreateElement("volume",           audiobin_);
   equalizer_        = engine_->CreateElement("equalizer-nbands", audiobin_);
+  stereo_panorama_  = engine_->CreateElement("audiopanorama",    audiobin_);
   volume_           = engine_->CreateElement("volume",           audiobin_);
   audioscale_       = engine_->CreateElement("audioresample",    audiobin_);
   convert           = engine_->CreateElement("audioconvert",     audiobin_);
 
   if (!queue_ || !audioconvert_ || !tee || !probe_queue || !probe_converter ||
       !probe_sink || !audio_queue || !equalizer_preamp_ || !equalizer_ ||
-      !volume_ || !audioscale_ || !convert) {
+      !stereo_panorama_ || !volume_ || !audioscale_ || !convert) {
     return false;
   }
 
@@ -310,6 +313,9 @@ bool GstEnginePipeline::Init() {
     g_object_unref(G_OBJECT(band));
   }
 
+  // Set the stereo balance.
+  g_object_set(G_OBJECT(stereo_panorama_), "panorama", stereo_balance_, NULL);
+
   // Set the buffer duration.  We set this on this queue instead of the
   // decode bin (in ReplaceDecodeBin()) because setting it on the decode bin
   // only affects network sources.
@@ -356,8 +362,8 @@ bool GstEnginePipeline::Init() {
 
   // Link everything else.
   gst_element_link(probe_queue, probe_converter);
-  gst_element_link_many(audio_queue, equalizer_preamp_, equalizer_, volume_,
-                        audioscale_, convert, audiosink_, NULL);
+  gst_element_link_many(audio_queue, equalizer_preamp_, equalizer_, stereo_panorama_,
+                        volume_, audioscale_, convert, audiosink_, NULL);
 
   // Add probes and handlers.
   gst_pad_add_buffer_probe(gst_element_get_static_pad(probe_converter, "src"), G_CALLBACK(HandoffCallback), this);
@@ -878,6 +884,11 @@ void GstEnginePipeline::SetEqualizerParams(int preamp, const QList<int>& band_ga
   UpdateEqualizer();
 }
 
+void GstEnginePipeline::SetStereoBalance(float value) {
+  stereo_balance_ = value;
+  UpdateStereoBalance();
+}
+
 void GstEnginePipeline::UpdateEqualizer() {
   // Update band gains
   for (int i=0 ; i<kEqBandCount ; ++i) {
@@ -900,6 +911,12 @@ void GstEnginePipeline::UpdateEqualizer() {
   g_object_set(G_OBJECT(equalizer_preamp_), "volume", preamp, NULL);
 }
 
+void GstEnginePipeline::UpdateStereoBalance() {
+  if (stereo_panorama_) {
+    g_object_set(G_OBJECT(stereo_panorama_), "panorama", stereo_balance_, NULL);
+  }
+}
+
 void GstEnginePipeline::SetVolume(int percent) {
   volume_percent_ = percent;
   UpdateVolume();

src/engines/gstenginepipeline.h

@@ -69,6 +69,7 @@ class GstEnginePipeline : public QObject {
   void SetEqualizerEnabled(bool enabled);
   void SetEqualizerParams(int preamp, const QList<int>& band_gains);
   void SetVolume(int percent);
+  void SetStereoBalance(float value);
   void StartFader(qint64 duration_nanosec,
                   QTimeLine::Direction direction = QTimeLine::Forward,
                   QTimeLine::CurveShape shape = QTimeLine::LinearCurve,
@@ -145,6 +146,7 @@ class GstEnginePipeline : public QObject {
 
   void UpdateVolume();
   void UpdateEqualizer();
+  void UpdateStereoBalance();
   bool ReplaceDecodeBin(GstElement* new_bin);
   bool ReplaceDecodeBin(const QUrl& url);
 
@@ -192,6 +194,11 @@ class GstEnginePipeline : public QObject {
   int eq_preamp_;
   QList<int> eq_band_gains_;
 
+  // Stereo balance.
+  // From -1.0 - 1.0
+  // -1.0 is left, 1.0 is right.
+  float stereo_balance_;
+
   // ReplayGain
   bool rg_enabled_;
   int rg_mode_;
@@ -263,6 +270,7 @@ class GstEnginePipeline : public QObject {
   GstElement* audioconvert2_;
   GstElement* equalizer_preamp_;
   GstElement* equalizer_;
+  GstElement* stereo_panorama_;
   GstElement* volume_;
   GstElement* audioscale_;
   GstElement* audiosink_;

src/ui/equalizer.cpp

@@ -17,8 +17,6 @@
 
 #include "equalizer.h"
 #include "ui_equalizer.h"
-#include "widgets/equalizerslider.h"
-#include "ui/iconloader.h"
 
 #include <QInputDialog>
 #include <QMessageBox>
@@ -26,6 +24,9 @@
 #include <QShortcut>
 #include <QtDebug>
 
+#include "ui/iconloader.h"
+#include "widgets/equalizerslider.h"
+
 // We probably don't need to translate these, right?
 const char* Equalizer::kGainText[] = {
   "60", "170", "310", "600", "1k", "3k", "6k", "12k", "14k", "16k"};
@@ -62,6 +63,7 @@ Equalizer::Equalizer(QWidget *parent)
   connect(ui_->preset, SIGNAL(currentIndexChanged(int)), SLOT(PresetChanged(int)));
   connect(ui_->preset_save, SIGNAL(clicked()), SLOT(SavePreset()));
   connect(ui_->preset_del, SIGNAL(clicked()), SLOT(DelPreset()));
+  connect(ui_->balance_slider, SIGNAL(valueChanged(int)), SLOT(StereoSliderChanged(int)));
 
   QShortcut* close = new QShortcut(QKeySequence::Close, this);
   connect(close, SIGNAL(activated()), SLOT(close()));
@@ -101,6 +103,10 @@ void Equalizer::ReloadSettings() {
   ui_->enable->setChecked(s.value("enabled", false).toBool());
   ui_->slider_container->setEnabled(ui_->enable->isChecked());
 
+  int stereo_balance = s.value("stereo_balance", 0).toInt();
+  ui_->balance_slider->setValue(stereo_balance);
+  StereoSliderChanged(stereo_balance);
+
   PresetChanged(selected_preset);
 }
 
@@ -232,6 +238,18 @@ Equalizer::Params Equalizer::current_params() const {
   return ret;
 }
 
+namespace {
+
+float Clamp(float min, float value, float max) {
+  return qMin(1.0f, qMax(-1.0f, value));
+}
+
+}
+
+float Equalizer::stereo_balance() const {
+  return Clamp(-1.0f, ui_->balance_slider->value(), 1.0f);
+}
+
 void Equalizer::ParametersChanged() {
   if (loading_)
     return;
@@ -259,6 +277,8 @@ void Equalizer::Save() {
 
   // Enabled?
   s.setValue("enabled", ui_->enable->isChecked());
+
+  s.setValue("stereo_balance", ui_->balance_slider->value());
 }
 
 void Equalizer::closeEvent(QCloseEvent* e) {
@@ -300,6 +320,11 @@ bool Equalizer::Params::operator !=(const Equalizer::Params& other) const {
   return ! (*this == other);
 }
 
+void Equalizer::StereoSliderChanged(int value) {
+  emit StereoBalanceChanged(stereo_balance());
+  Save();
+}
+
 QDataStream &operator<<(QDataStream& s, const Equalizer::Params& p) {
   s << p.preamp;
   for (int i=0 ; i<Equalizer::kBands ; ++i)

src/ui/equalizer.h

@@ -52,10 +52,12 @@ class Equalizer : public QDialog {
   int preamp_value() const;
   QList<int> gain_values() const;
   Params current_params() const;
+  float stereo_balance() const;
 
  signals:
   void EnabledChanged(bool enabled);
   void ParametersChanged(int preamp, const QList<int>& band_gains);
+  void StereoBalanceChanged(float balance);
 
  protected:
   void closeEvent(QCloseEvent *);
@@ -67,6 +69,7 @@ class Equalizer : public QDialog {
   void SavePreset();
   void DelPreset();
   void Save();
+  void StereoSliderChanged(int value);
 
  private:
   EqualizerSlider* AddSlider(const QString& label);

src/ui/equalizer.ui

@@ -81,6 +81,22 @@
      <layout class="QHBoxLayout" name="horizontalLayout_2"/>
     </widget>
    </item>
+   <item>
+    <widget class="QSlider" name="balance_slider">
+     <property name="maximum">
+      <number>100</number>
+     </property>
+     <property name="minimum">
+      <number>-100</number>
+     </property>
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+     <property name="tickPosition">
+      <enum>QSlider::TicksBelow</enum>
+     </property>
+    </widget>
+   </item>
   </layout>
  </widget>
  <tabstops>

src/ui/mainwindow.cpp

@@ -642,9 +642,12 @@ MainWindow::MainWindow(Application* app,
           app_->player()->engine(), SLOT(SetEqualizerParameters(int,QList<int>)));
   connect(equalizer_.get(), SIGNAL(EnabledChanged(bool)),
           app_->player()->engine(), SLOT(SetEqualizerEnabled(bool)));
+  connect(equalizer_.get(), SIGNAL(StereoBalanceChanged(float)),
+          app_->player()->engine(), SLOT(SetStereoBalance(float)));
   app_->player()->engine()->SetEqualizerEnabled(equalizer_->is_enabled());
   app_->player()->engine()->SetEqualizerParameters(
       equalizer_->preamp_value(), equalizer_->gain_values());
+  app_->player()->engine()->SetStereoBalance(equalizer_->stereo_balance());
 
   // Statusbar widgets
   ui_->playlist_summary->setMinimumWidth(QFontMetrics(font()).width("WW selected of WW tracks - [ WW:WW ]"));