further progress on first attempt

app/render/backend/opengl/openglbackend.h

@@ -33,7 +33,7 @@ public:
 protected:
   virtual void TextureToFrame(const QVariant& texture, FramePtr frame) const override;
 
-  virtual QVariant FrameToTexture(FramePtr frame) const override;
+  virtual NodeValue FrameToTexture(FramePtr frame) const override;
 
   virtual void ProcessNodeEvent(const Node *node, const TimeRange &range, NodeValueDatabase &input_params, NodeValueTable &output_params) const override;
 

app/render/backend/renderbackend.cpp

@@ -211,13 +211,22 @@ void RenderBackend::FootageProcessingEvent(StreamPtr stream, const TimeRange &in
 
   } else if (stream->type() != Stream::kAudio) {
 
-    NodeValue value = GetDataFromStream(stream, input_time);
-
-    table->Push(value);
+    table->Push(GetDataFromStream(stream, input_time));
 
   }
 }
 
+NodeValue RenderBackend::GetDataFromStream(StreamPtr stream, const TimeRange &input_time) const
+{
+  DecoderPtr decoder = ResolveDecoderFromInput(stream);
+
+  if (decoder) {
+    return FrameToTexture(decoder, stream, input_time);
+  }
+
+  return NodeValue();
+}
+
 NodeValueTable RenderBackend::GenerateBlockTable(const TrackOutput *track, const TimeRange &range) const
 {
   if (track->track_type() == Timeline::kTrackTypeAudio) {

app/render/backend/renderbackend.h

@@ -42,8 +42,14 @@ public:
 
   void CancelQueue();
 
+  /**
+   * @brief Asynchronously generate a hash at a given time
+   */
   QFuture<QByteArray> Hash(const rational& time);
 
+  /**
+   * @brief Asynchronously generate a frame at a given time
+   */
   QFuture<FramePtr> RenderFrame(const rational& time);
 
   void SetDivider(const int& divider);
@@ -60,7 +66,7 @@ public slots:
 protected:
   virtual void TextureToFrame(const QVariant& texture, FramePtr frame) const = 0;
 
-  virtual QVariant FrameToTexture(FramePtr frame) const = 0;
+  virtual NodeValue FrameToTexture(FramePtr frame) const = 0;
 
   virtual void FootageProcessingEvent(StreamPtr stream, const TimeRange &input_time, NodeValueTable* table) const override;
 
@@ -78,6 +84,10 @@ private:
 
   VideoRenderingParams video_params() const;
 
+  NodeValue GetDataFromStream(StreamPtr stream, const TimeRange& input_time) const;
+
+  DecoderPtr ResolveDecoderFromInput(StreamPtr stream) const;
+
   class CopyMap {
   public:
     CopyMap();