Disable FFT when no analyzer in use.

src/analyzers/analyzercontainer.cpp

@@ -15,10 +15,11 @@
 */
 
 #include "analyzercontainer.h"
-#include "glblockanalyzer.h"
 #include "baranalyzer.h"
 #include "blockanalyzer.h"
 #include "boomanalyzer.h"
+#include "engines/enginebase.h"
+#include "glblockanalyzer.h"
 #include "sonogram.h"
 #include "turbine.h"
 
@@ -104,12 +105,19 @@ void AnalyzerContainer::SetEngine(EngineBase *engine) {
   if (current_analyzer_)
     QMetaObject::invokeMethod(current_analyzer_, "set_engine", Qt::DirectConnection, Q_ARG(Engine::Base*, engine));
   engine_ = engine;
+  if (engine_) {
+    engine_->SetSpectrum(current_analyzer_);
+  }
 }
 
 void AnalyzerContainer::DisableAnalyzer() {
   delete current_analyzer_;
   current_analyzer_ = NULL;
 
+  if (engine_) {
+    engine_->SetSpectrum(false);
+  }
+
   Save();
 }
 
@@ -130,6 +138,10 @@ void AnalyzerContainer::ChangeAnalyzer(int id) {
 
   layout()->addWidget(current_analyzer_);
 
+  if (engine_) {
+    engine_->SetSpectrum(true);
+  }
+
   Save();
 }
 

src/engines/enginebase.h

@@ -71,6 +71,8 @@ class Base : public QObject, boost::noncopyable {
   bool is_crossfade_enabled() const { return crossfade_enabled_; }
   bool is_autocrossfade_enabled() const { return autocrossfade_enabled_; }
 
+  virtual void SetSpectrum(bool) {}
+
   static const char* kSettingsGroup;
   static const int kScopeSize = 1024;
 

src/engines/gstengine.cpp

@@ -74,7 +74,8 @@ GstEngine::GstEngine()
     rg_compression_(true),
     seek_timer_(new QTimer(this)),
     timer_id_(-1),
-    next_element_id_(0)
+    next_element_id_(0),
+    spectrum_enabled_(false)
 {
   seek_timer_->setSingleShot(true);
   seek_timer_->setInterval(kSeekDelay);
@@ -468,7 +469,6 @@ bool GstEngine::Load(const QUrl& url, Engine::TrackChangeType change) {
   current_pipeline_ = pipeline;
   preload_pipeline_.reset();
 
-  qDebug() << current_pipeline_.get();
   connect(current_pipeline_.get(), SIGNAL(SpectrumAvailable(const QVector<float>&)),
           this, SIGNAL(SpectrumAvailable(const QVector<float>&)));
 
@@ -537,6 +537,8 @@ void GstEngine::PlayDone() {
     Seek(watcher->data());
   }
 
+  SetSpectrum(spectrum_enabled_);
+
   emit StateChanged(Engine::Playing);
 }
 
@@ -857,3 +859,10 @@ int GstEngine::AllGloryToTheHypnotoad() {
   pipeline->SetVolume(5);  // Hypnotoad is *loud*.
   return AddBackgroundStream(pipeline);
 }
+
+void GstEngine::SetSpectrum(bool enable) {
+  spectrum_enabled_ = enable;
+  if (current_pipeline_) {
+    current_pipeline_->SetSpectrum(enable);
+  }
+}

src/engines/gstengine.h

@@ -103,6 +103,8 @@ class GstEngine : public Engine::Base, public BufferConsumer {
   void AddBufferConsumer(BufferConsumer* consumer);
   void RemoveBufferConsumer(BufferConsumer* consumer);
 
+  void SetSpectrum(bool enable);
+
  protected:
   void SetVolumeSW(uint percent);
   void timerEvent(QTimerEvent*);
@@ -184,6 +186,8 @@ class GstEngine : public Engine::Base, public BufferConsumer {
   int next_element_id_;
 
   QHash<int, boost::shared_ptr<GstEnginePipeline> > background_streams_;
+
+  bool spectrum_enabled_;
 };
 
 

src/engines/gstenginepipeline.cpp

@@ -168,8 +168,8 @@ bool GstEnginePipeline::Init() {
   g_object_set(G_OBJECT(spectrum_),
       "bands", kSpectrumBands,
       "threshold", kSpectrumThreshold,
-      "interval", kSpectrumIntervalns,
       NULL);
+  SetSpectrum(false);  // Spectrum disabled by default.
 
   GstPad* pad = gst_element_get_pad(audioconvert_, "sink");
   gst_element_add_pad(audiobin_, gst_ghost_pad_new("sink", pad));
@@ -604,3 +604,9 @@ void GstEnginePipeline::RemoveAllBufferConsumers() {
   QMutexLocker l(&buffer_consumers_mutex_);
   buffer_consumers_.clear();
 }
+
+void GstEnginePipeline::SetSpectrum(bool enable) {
+  g_object_set(spectrum_,
+      "interval", enable ? kSpectrumIntervalns : std::numeric_limits<quint64>::max(),
+      NULL);
+}

src/engines/gstenginepipeline.h

@@ -78,6 +78,8 @@ class GstEnginePipeline : public QObject {
 
   QUrl redirect_url() const { return redirect_url_; }
 
+  void SetSpectrum(bool enable);
+
  public slots:
   void SetVolumeModifier(qreal mod);