clear decoders when viewer is disconnected

app/render/backend/renderbackend.cpp

@@ -139,6 +139,10 @@ void RenderBackend::SetViewerNode(ViewerOutput *viewer_node)
                &PlaybackCache::Invalidated,
                this,
                &RenderBackend::AutoCacheAudioInvalidated);
+
+    foreach (const WorkerData& worker, workers_) {
+      worker.worker->ClearDecoders();
+    }
   }
 
   if (viewer_node) {

app/render/backend/renderworker.cpp

@@ -164,6 +164,11 @@ void RenderWorker::RenderAudio(RenderTicketPtr ticket, ViewerOutput* viewer, con
   emit FinishedJob();
 }
 
+void RenderWorker::ClearDecoders()
+{
+  decoder_cache_.clear();
+}
+
 NodeValueTable RenderWorker::GenerateBlockTable(const TrackOutput *track, const TimeRange &range)
 {
   if (track->track_type() == Timeline::kTrackTypeAudio) {

app/render/backend/renderworker.h

@@ -107,6 +107,8 @@ public:
 
   void RenderAudio(RenderTicketPtr ticket, ViewerOutput* viewer, const TimeRange& range);
 
+  void ClearDecoders();
+
 protected:
   virtual void TextureToFrame(const QVariant& texture, FramePtr frame, const QMatrix4x4 &mat) const = 0;