diff --git a/app/audio/audiomanager.cpp b/app/audio/audiomanager.cpp
index df4ca479e..956c4a624 100644
--- a/app/audio/audiomanager.cpp
+++ b/app/audio/audiomanager.cpp
@@ -194,6 +194,7 @@ AudioManager::AudioManager() :
   RefreshDevices();
 
   connect(&output_manager_, &AudioOutputManager::SentSamples, this, &AudioManager::SentSamples);
+  connect(&output_manager_, &AudioOutputManager::OutputNotified, this, &AudioManager::OutputNotified);
 
   output_manager_.SetEnableSendingSamples(true);
 }
diff --git a/app/audio/audiomanager.h b/app/audio/audiomanager.h
index 8a806652e..73e990114 100644
--- a/app/audio/audiomanager.h
+++ b/app/audio/audiomanager.h
@@ -102,6 +102,8 @@ signals:
 
   void SentSamples(QVector<double> averages);
 
+  void OutputNotified();
+
 private:
   AudioManager();
 
diff --git a/app/audio/outputmanager.cpp b/app/audio/outputmanager.cpp
index de27d92ac..8d601f07c 100644
--- a/app/audio/outputmanager.cpp
+++ b/app/audio/outputmanager.cpp
@@ -54,7 +54,7 @@ void AudioOutputManager::Push(const QByteArray& samples)
   ResetToPushMode();
 
   // Start pushing samples to the output
-  OutputNotified();
+  PushMoreSamples();
 }
 
 void AudioOutputManager::ResetToPushMode()
@@ -92,7 +92,7 @@ void AudioOutputManager::PullFromDevice(QIODevice *device, int playback_speed)
   output_->start(&device_proxy_);
 }
 
-void AudioOutputManager::OutputNotified()
+void AudioOutputManager::PushMoreSamples()
 {
   // Check if we're currently in push mode and if we have samples to push
   if (!push_device_ || pushed_samples_.isEmpty()) {
@@ -139,6 +139,7 @@ void AudioOutputManager::SetOutputDevice(QAudioDeviceInfo info, QAudioFormat for
   output_ = std::unique_ptr<QAudioOutput>(new QAudioOutput(info, format, this));
   output_->setNotifyInterval(1);
   push_device_ = output_->start();
+  connect(output_.get(), &QAudioOutput::notify, this, &AudioOutputManager::PushMoreSamples);
   connect(output_.get(), &QAudioOutput::notify, this, &AudioOutputManager::OutputNotified);
 }
 
diff --git a/app/audio/outputmanager.h b/app/audio/outputmanager.h
index 4b00208de..06024f4d1 100644
--- a/app/audio/outputmanager.h
+++ b/app/audio/outputmanager.h
@@ -69,6 +69,8 @@ signals:
    */
   void SentSamples(QVector<double> averages);
 
+  void OutputNotified();
+
 private:
   void ProcessAverages(const char* data, int length);
 
@@ -83,7 +85,7 @@ private:
   AudioOutputDeviceProxy device_proxy_;
 
 private slots:
-  void OutputNotified();
+  void PushMoreSamples();
 };
 
 #endif // AUDIOHYBRIDDEVICE_H
diff --git a/app/node/CMakeLists.txt b/app/node/CMakeLists.txt
index 68bb5194f..bb8f9a42f 100644
--- a/app/node/CMakeLists.txt
+++ b/app/node/CMakeLists.txt
@@ -46,6 +46,8 @@ set(OLIVE_SOURCES
   node/output.cpp
   node/param.h
   node/param.cpp
+  node/traverser.h
+  node/traverser.cpp
   node/value.h
   node/value.cpp
   PARENT_SCOPE
diff --git a/app/node/input/media/audio/audio.cpp b/app/node/input/media/audio/audio.cpp
index ccfb52f56..6f7992de9 100644
--- a/app/node/input/media/audio/audio.cpp
+++ b/app/node/input/media/audio/audio.cpp
@@ -28,8 +28,3 @@ QString AudioInput::Description() const
 {
   return tr("Import an audio footage stream.");
 }
-
-NodeValueTable AudioInput::Value(const NodeValueDatabase &value) const
-{
-  return value[footage_input_];
-}
diff --git a/app/node/input/media/audio/audio.h b/app/node/input/media/audio/audio.h
index 641b4f8de..86aa8d330 100644
--- a/app/node/input/media/audio/audio.h
+++ b/app/node/input/media/audio/audio.h
@@ -15,9 +15,6 @@ public:
   virtual QString Category() const override;
   virtual QString Description() const override;
 
-protected:
-  virtual NodeValueTable Value(const NodeValueDatabase& value) const override;
-
 private:
 };
 
diff --git a/app/node/output/viewer/viewer.cpp b/app/node/output/viewer/viewer.cpp
index b86623419..f1327dcdd 100644
--- a/app/node/output/viewer/viewer.cpp
+++ b/app/node/output/viewer/viewer.cpp
@@ -20,6 +20,8 @@
 
 #include "viewer.h"
 
+#include "node/traverser.h"
+
 ViewerOutput::ViewerOutput()
 {
   texture_input_ = new NodeInput("tex_in", NodeInput::kTexture);
@@ -28,9 +30,6 @@ ViewerOutput::ViewerOutput()
   samples_input_ = new NodeInput("samples_in", NodeInput::kSamples);
   AddInput(samples_input_);
 
-  length_input_ = new NodeInput("length_in", NodeInput::kRational);
-  AddInput(length_input_);
-
   // Create TrackList instances
   track_inputs_.resize(Timeline::kTrackTypeCount);
   track_lists_.resize(Timeline::kTrackTypeCount);
@@ -91,11 +90,6 @@ NodeInput *ViewerOutput::samples_input() const
   return samples_input_;
 }
 
-NodeInput *ViewerOutput::length_input() const
-{
-  return length_input_;
-}
-
 void ViewerOutput::InvalidateCache(const rational &start_range, const rational &end_range, NodeInput *from)
 {
   Node::InvalidateCache(start_range, end_range, from);
@@ -104,8 +98,6 @@ void ViewerOutput::InvalidateCache(const rational &start_range, const rational &
     emit VideoChangedBetween(TimeRange(start_range, end_range));
   } else if (from == samples_input()) {
     emit AudioChangedBetween(TimeRange(start_range, end_range));
-  } else if (from == length_input()) {
-    emit LengthChanged(Length());
   }
 
   SendInvalidateCache(start_range, end_range);
@@ -146,18 +138,23 @@ void ViewerOutput::set_audio_params(const AudioParams &audio)
 
 rational ViewerOutput::Length()
 {
-  if (!length_input_->IsConnected()) {
-    return timeline_length_;
+  NodeTraverser traverser;
+
+  rational video_length;
+
+  if (texture_input_->IsConnected()) {
+    NodeValueTable t = traverser.ProcessNode(NodeDependency(texture_input_->get_connected_node(), 0, 0));
+    video_length = t.Get(NodeParam::kNumber, "length").value<rational>();
   }
 
-  Node* connected_node = length_input_->get_connected_node();
+  rational audio_length;
 
-  if (connected_node) {
-    // This is kind of messy?
-    return connected_node->Value(NodeValueDatabase()).Get(NodeParam::kNumber, "length").value<rational>();
+  if (samples_input_->IsConnected()) {
+    NodeValueTable t = traverser.ProcessNode(NodeDependency(samples_input_->get_connected_node(), 0, 0));
+    audio_length = t.Get(NodeParam::kNumber, "length").value<rational>();
   }
 
-  return 0;
+  return qMax(video_length, qMax(audio_length, timeline_length_));
 }
 
 const QUuid &ViewerOutput::uuid() const
diff --git a/app/node/output/viewer/viewer.h b/app/node/output/viewer/viewer.h
index abdcd3f41..2d86dfc0e 100644
--- a/app/node/output/viewer/viewer.h
+++ b/app/node/output/viewer/viewer.h
@@ -52,7 +52,6 @@ public:
 
   NodeInput* texture_input() const;
   NodeInput* samples_input() const;
-  NodeInput* length_input() const;
 
   virtual void InvalidateCache(const rational &start_range, const rational &end_range, NodeInput *from = nullptr) override;
   virtual void InvalidateVisible(NodeInput *from) override;
@@ -117,8 +116,6 @@ private:
 
   NodeInput* samples_input_;
 
-  NodeInput* length_input_;
-
   VideoParams video_params_;
 
   AudioParams audio_params_;
diff --git a/app/node/traverser.cpp b/app/node/traverser.cpp
new file mode 100644
index 000000000..fb3f28239
--- /dev/null
+++ b/app/node/traverser.cpp
@@ -0,0 +1,76 @@
+#include "traverser.h"
+
+#include "node.h"
+
+NodeTraverser::NodeTraverser()
+{
+
+}
+
+NodeValueDatabase NodeTraverser::GenerateDatabase(const Node* node, const TimeRange &range)
+{
+  NodeValueDatabase database;
+
+  // We need to insert tables into the database for each input
+  foreach (NodeParam* param, node->parameters()) {
+    if (IsCancelled()) {
+      return NodeValueDatabase();
+    }
+
+    if (param->type() == NodeParam::kInput) {
+      NodeInput* input = static_cast<NodeInput*>(param);
+      TimeRange input_time = node->InputTimeAdjustment(input, range);
+
+      NodeValueTable table = ProcessInput(input, input_time);
+
+      InputProcessingEvent(input, input_time, &table);
+
+      database.Insert(input, table);
+    }
+  }
+
+  return database;
+}
+
+NodeValueTable NodeTraverser::ProcessNode(const NodeDependency& dep)
+{
+  const Node* node = dep.node();
+
+  if (node->IsTrack()) {
+    // If the range is not wholly contained in this Block, we'll need to do some extra processing
+    return RenderBlock(static_cast<const TrackOutput*>(node), dep.range());
+  }
+
+  // FIXME: Cache certain values here if we've already processed them before
+
+  // Generate database of input values of node
+  NodeValueDatabase database = GenerateDatabase(node, dep.range());
+
+  // By this point, the node should have all the inputs it needs to render correctly
+  NodeValueTable table = node->Value(database);
+
+  ProcessNodeEvent(node, dep.range(), database, &table);
+
+  return table;
+}
+
+NodeValueTable NodeTraverser::RenderBlock(const TrackOutput *track, const TimeRange &range)
+{
+  // By default, don't bother traversing blocks
+  return NodeValueTable();
+}
+
+NodeValueTable NodeTraverser::ProcessInput(const NodeInput *input, const TimeRange& range)
+{
+  if (input->IsConnected()) {
+    // Value will equal something from the connected node, follow it
+    return ProcessNode(NodeDependency(input->get_connected_node(), range));
+  } else {
+    // Push onto the table the value at this time from the input
+    QVariant input_value = input->get_value_at_time(range.in());
+
+    NodeValueTable table;
+    table.Push(input->data_type(), input_value);
+    return table;
+  }
+}
diff --git a/app/node/traverser.h b/app/node/traverser.h
new file mode 100644
index 000000000..8166a7987
--- /dev/null
+++ b/app/node/traverser.h
@@ -0,0 +1,31 @@
+#ifndef NODETRAVERSER_H
+#define NODETRAVERSER_H
+
+#include "codec/decoder.h"
+#include "common/cancelableobject.h"
+#include "dependency.h"
+#include "node/output/track/track.h"
+#include "project/item/footage/stream.h"
+#include "value.h"
+
+class NodeTraverser : public CancelableObject
+{
+public:
+  NodeTraverser();
+
+  NodeValueTable ProcessNode(const NodeDependency &dep);
+
+protected:
+  NodeValueDatabase GenerateDatabase(const Node *node, const TimeRange &range);
+
+  virtual NodeValueTable RenderBlock(const TrackOutput *track, const TimeRange& range);
+
+  NodeValueTable ProcessInput(const NodeInput* input, const TimeRange &range);
+
+  virtual void InputProcessingEvent(NodeInput*, const TimeRange&, NodeValueTable*){}
+
+  virtual void ProcessNodeEvent(const Node*, const TimeRange&, const NodeValueDatabase&, NodeValueTable*){}
+
+};
+
+#endif // NODETRAVERSER_H
diff --git a/app/node/value.cpp b/app/node/value.cpp
index 2f5fc11a5..0ef541256 100644
--- a/app/node/value.cpp
+++ b/app/node/value.cpp
@@ -58,13 +58,9 @@ NodeValueTable::NodeValueTable()
 
 QVariant NodeValueTable::Get(const NodeParam::DataType &type, const QString &tag) const
 {
-  int value_index = GetInternal(type, tag);
+  NodeValue v = GetWithMeta(type, tag);
 
-  if (value_index >= 0) {
-    return values_.at(value_index).data();
-  }
-
-  return QVariant();
+  return v.data();
 }
 
 NodeValue NodeValueTable::GetWithMeta(const NodeParam::DataType &type, const QString &tag) const
diff --git a/app/render/backend/renderworker.cpp b/app/render/backend/renderworker.cpp
index 63aa3d308..07512a4ca 100644
--- a/app/render/backend/renderworker.cpp
+++ b/app/render/backend/renderworker.cpp
@@ -87,95 +87,41 @@ bool RenderWorker::IsStarted()
   return started_;
 }
 
-NodeValueTable RenderWorker::ProcessNode(const NodeDependency& dep)
-{
-  const Node* node = dep.node();
-
-  if (node->IsTrack()) {
-    // If the range is not wholly contained in this Block, we'll need to do some extra processing
-    return RenderBlock(static_cast<const TrackOutput*>(node), dep.range());
-  }
-
-  // FIXME: Cache certain values here if we've already processed them before
-
-  // Generate database of input values of node
-  NodeValueDatabase database = GenerateDatabase(node, dep.range());
-
-  // By this point, the node should have all the inputs it needs to render correctly
-  NodeValueTable table = node->Value(database);
-
-  // Check if we have a shader for this output
-  RunNodeAccelerated(node, dep.range(), database, &table);
-
-  return table;
-}
-
-NodeValueTable RenderWorker::ProcessInput(const NodeInput *input, const TimeRange& range)
-{
-  if (input->IsConnected()) {
-    // Value will equal something from the connected node, follow it
-    return ProcessNode(NodeDependency(input->get_connected_node(), range));
-  } else {
-    // Push onto the table the value at this time from the input
-    QVariant input_value = input->get_value_at_time(range.in());
-
-    NodeValueTable table;
-    table.Push(input->data_type(), input_value);
-    return table;
-  }
-}
-
 void RenderWorker::ReportUnavailableFootage(StreamPtr stream, Decoder::RetrieveState state, const rational& stream_time)
 {
   emit FootageUnavailable(stream, state, path_.range(), stream_time);
 }
 
+void RenderWorker::InputProcessingEvent(NodeInput* input, const TimeRange& input_time, NodeValueTable *table)
+{
+  // Exception for Footage types where we actually retrieve some Footage data from a decoder
+  if (input->data_type() == NodeParam::kFootage) {
+    StreamPtr stream = ResolveStreamFromInput(input);
+
+    if (stream) {
+      DecoderPtr decoder = ResolveDecoderFromInput(stream);
+
+      if (decoder) {
+
+        Decoder::RetrieveState state = decoder->GetRetrieveState(input_time.out());
+
+        if (state == Decoder::kReady) {
+          FrameToValue(decoder, stream, input_time, table);
+        } else {
+          ReportUnavailableFootage(stream, state, input_time.out());
+        }
+      }
+    }
+  }
+}
+
+void RenderWorker::ProcessNodeEvent(const Node *node, const TimeRange &range, const NodeValueDatabase &input_params, NodeValueTable* output_params)
+{
+  // Check if we have a shader for this output
+  RunNodeAccelerated(node, range, input_params, output_params);
+}
+
 const NodeDependency &RenderWorker::CurrentPath() const
 {
   return path_;
 }
-
-
-#include "common/functiontimer.h"
-NodeValueDatabase RenderWorker::GenerateDatabase(const Node* node, const TimeRange &range)
-{
-  NodeValueDatabase database;
-
-  // We need to insert tables into the database for each input
-  foreach (NodeParam* param, node->parameters()) {
-    if (IsCancelled()) {
-      return NodeValueDatabase();
-    }
-
-    if (param->type() == NodeParam::kInput) {
-      NodeInput* input = static_cast<NodeInput*>(param);
-      TimeRange input_time = node->InputTimeAdjustment(input, range);
-
-      NodeValueTable table = ProcessInput(input, input_time);
-
-      // Exception for Footage types where we actually retrieve some Footage data from a decoder
-      if (input->data_type() == NodeParam::kFootage) {
-        StreamPtr stream = ResolveStreamFromInput(input);
-
-        if (stream) {
-          DecoderPtr decoder = ResolveDecoderFromInput(stream);
-
-          if (decoder) {
-
-            Decoder::RetrieveState state = decoder->GetRetrieveState(input_time.out());
-
-            if (state == Decoder::kReady) {
-              FrameToValue(decoder, stream, input_time, &table);
-            } else {
-              ReportUnavailableFootage(stream, state, input_time.out());
-            }
-          }
-        }
-      }
-
-      database.Insert(input, table);
-    }
-  }
-
-  return database;
-}
diff --git a/app/render/backend/renderworker.h b/app/render/backend/renderworker.h
index 7965e297e..885d3c60f 100644
--- a/app/render/backend/renderworker.h
+++ b/app/render/backend/renderworker.h
@@ -3,13 +3,13 @@
 
 #include <QObject>
 
-#include "common/cancelableobject.h"
 #include "common/constructors.h"
-#include "node/output/track/track.h"
-#include "node/node.h"
 #include "decodercache.h"
+#include "node/node.h"
+#include "node/output/track/track.h"
+#include "node/traverser.h"
 
-class RenderWorker : public QObject, public CancelableObject
+class RenderWorker : public QObject, public NodeTraverser
 {
   Q_OBJECT
 public:
@@ -38,24 +38,21 @@ protected:
 
   virtual void RunNodeAccelerated(const Node *node, const TimeRange& range, const NodeValueDatabase &input_params, NodeValueTable* output_params);
 
-  StreamPtr ResolveStreamFromInput(NodeInput* input);
-  DecoderPtr ResolveDecoderFromInput(StreamPtr stream);
-
   virtual void FrameToValue(DecoderPtr decoder, StreamPtr stream, const TimeRange &range, NodeValueTable* table) = 0;
 
-  NodeValueTable ProcessNode(const NodeDependency &dep);
-
-  virtual NodeValueTable RenderBlock(const TrackOutput *track, const TimeRange& range) = 0;
-
-  NodeValueTable ProcessInput(const NodeInput* input, const TimeRange &range);
-
   virtual void ReportUnavailableFootage(StreamPtr stream, Decoder::RetrieveState state, const rational& stream_time);
 
+  virtual void InputProcessingEvent(NodeInput *input, const TimeRange &input_time, NodeValueTable* table) override;
+
+  virtual void ProcessNodeEvent(const Node *node, const TimeRange &range, const NodeValueDatabase &input_params, NodeValueTable* output_params) override;
+
+  StreamPtr ResolveStreamFromInput(NodeInput* input);
+
+  DecoderPtr ResolveDecoderFromInput(StreamPtr stream);
+
   const NodeDependency& CurrentPath() const;
 
 private:
-  NodeValueDatabase GenerateDatabase(const Node *node, const TimeRange &range);
-
   bool started_;
 
   DecoderCache* decoder_cache_;
diff --git a/app/widget/viewer/footageviewer.cpp b/app/widget/viewer/footageviewer.cpp
index 9b0c18db4..8e3f7ec8d 100644
--- a/app/widget/viewer/footageviewer.cpp
+++ b/app/widget/viewer/footageviewer.cpp
@@ -13,9 +13,13 @@ FootageViewerWidget::FootageViewerWidget(QWidget *parent) :
   audio_node_ = new AudioInput();
   viewer_node_ = new ViewerOutput();
 
+  waveform_view_ = new QWidget();
+  waveform_view_->setAutoFillBackground(true);
+  waveform_view_->setStyleSheet("background: black;");
+  stack()->addWidget(waveform_view_);
+
   NodeParam::ConnectEdge(video_node_->output(), viewer_node_->texture_input());
   NodeParam::ConnectEdge(audio_node_->output(), viewer_node_->samples_input());
-  NodeParam::ConnectEdge(video_node_->output(), viewer_node_->length_input());
 
   connect(gl_widget_, &ViewerGLWidget::DragStarted, this, &FootageViewerWidget::StartFootageDrag);
 }
@@ -55,6 +59,10 @@ void FootageViewerWidget::SetFootage(Footage *footage)
     if (video_stream) {
       video_node_->SetFootage(video_stream);
       viewer_node_->set_video_params(VideoParams(video_stream->width(), video_stream->height(), video_stream->frame_rate().flipped()));
+
+      stack()->setCurrentWidget(gl_widget_);
+    } else {
+      stack()->setCurrentWidget(waveform_view_);
     }
 
     if (audio_stream) {
@@ -79,7 +87,6 @@ void FootageViewerWidget::StartFootageDrag()
     return;
   }
 
-  qDebug() << "Drag start!";
   QDrag* drag = new QDrag(this);
   QMimeData* mimedata = new QMimeData();
 
diff --git a/app/widget/viewer/footageviewer.h b/app/widget/viewer/footageviewer.h
index dc1634291..055906bd5 100644
--- a/app/widget/viewer/footageviewer.h
+++ b/app/widget/viewer/footageviewer.h
@@ -27,6 +27,8 @@ private:
 
   ViewerOutput* viewer_node_;
 
+  QWidget* waveform_view_;
+
 private slots:
   void StartFootageDrag();
 
diff --git a/app/widget/viewer/viewer.cpp b/app/widget/viewer/viewer.cpp
index f14080eed..6f42faaae 100644
--- a/app/widget/viewer/viewer.cpp
+++ b/app/widget/viewer/viewer.cpp
@@ -47,9 +47,13 @@ ViewerWidget::ViewerWidget(QWidget *parent) :
   QVBoxLayout* layout = new QVBoxLayout(this);
   layout->setMargin(0);
 
+  // Set up stacked widget to allow switching away from the viewer widget
+  stack_ = new QStackedWidget();
+  layout->addWidget(stack_);
+
   // Create main OpenGL-based view
   sizer_ = new ViewerSizer();
-  layout->addWidget(sizer_);
+  stack_->addWidget(sizer_);
 
   gl_widget_ = new ViewerGLWidget();
   connect(gl_widget_, &ViewerGLWidget::customContextMenuRequested, this, &ViewerWidget::ShowContextMenu);
@@ -111,7 +115,13 @@ void ViewerWidget::TimeChangedEvent(const int64_t &i)
 
 void ViewerWidget::ConnectNodeInternal(ViewerOutput *n)
 {
-  SetTimebase(n->video_params().time_base());
+  if (!n->video_params().time_base().isNull()) {
+    SetTimebase(n->video_params().time_base());
+  } else if (n->audio_params().sample_rate() > 0) {
+    SetTimebase(rational(1, n->audio_params().sample_rate()));
+  } else {
+    SetTimebase(rational());
+  }
 
   connect(n, &ViewerOutput::TimebaseChanged, this, &ViewerWidget::SetTimebase);
   connect(n, &ViewerOutput::SizeChanged, this, &ViewerWidget::SizeChangedSlot);
@@ -139,7 +149,7 @@ void ViewerWidget::DisconnectNodeInternal(ViewerOutput *n)
 {
   Pause();
 
-  SetTimebase(0);
+  SetTimebase(rational());
 
   disconnect(n, &ViewerOutput::TimebaseChanged, this, &ViewerWidget::SetTimebase);
   disconnect(n, &ViewerOutput::SizeChanged, this, &ViewerWidget::SizeChangedSlot);
@@ -171,6 +181,11 @@ void ViewerWidget::resizeEvent(QResizeEvent *event)
   }
 }
 
+QStackedWidget *ViewerWidget::stack() const
+{
+  return stack_;
+}
+
 void ViewerWidget::TogglePlayPause()
 {
   if (IsPlaying()) {
@@ -251,7 +266,11 @@ void ViewerWidget::PlayInternal(int speed)
 
   controls_->ShowPauseButton();
 
-  connect(gl_widget_, &ViewerGLWidget::frameSwapped, this, &ViewerWidget::PlaybackTimerUpdate);
+  if (stack_->currentWidget() == gl_widget_) {
+    connect(gl_widget_, &ViewerGLWidget::frameSwapped, this, &ViewerWidget::PlaybackTimerUpdate);
+  } else {
+    connect(AudioManager::instance(), &AudioManager::OutputNotified, this, &ViewerWidget::PlaybackTimerUpdate);
+  }
 }
 
 void ViewerWidget::PushScrubbedAudio()
@@ -387,7 +406,11 @@ void ViewerWidget::Pause()
     playback_speed_ = 0;
     controls_->ShowPlayButton();
 
-    disconnect(gl_widget_, &ViewerGLWidget::frameSwapped, this, &ViewerWidget::PlaybackTimerUpdate);
+    if (stack_->currentWidget() == gl_widget_) {
+      disconnect(gl_widget_, &ViewerGLWidget::frameSwapped, this, &ViewerWidget::PlaybackTimerUpdate);
+    } else {
+      disconnect(AudioManager::instance(), &AudioManager::OutputNotified, this, &ViewerWidget::PlaybackTimerUpdate);
+    }
   }
 }
 
diff --git a/app/widget/viewer/viewer.h b/app/widget/viewer/viewer.h
index a84aebc59..a5e38febe 100644
--- a/app/widget/viewer/viewer.h
+++ b/app/widget/viewer/viewer.h
@@ -115,6 +115,8 @@ protected:
 
   virtual void resizeEvent(QResizeEvent *event) override;
 
+  QStackedWidget* stack() const;
+
   OpenGLBackend* video_renderer_;
   AudioBackend* audio_renderer_;
 
@@ -131,6 +133,8 @@ private:
 
   int CalculateDivider();
 
+  QStackedWidget* stack_;
+
   ViewerSizer* sizer_;
 
   PlaybackControls* controls_;