first commit

nodes/vp_des_node.h

@@ -0,0 +1,36 @@
+#pragma once
+
+#include <string>
+
+#include "vp_node.h"
+#include "vp_stream_status_hookable.h"
+
+namespace vp_nodes {
+    // base class for des nodes, end point of meta/pipeline.
+    class vp_des_node: public vp_node, public vp_stream_status_hookable {
+    private:
+        // cache for stream status at current des node.
+        vp_stream_status stream_status;
+
+        // period(ms) to calculate output fps
+        int fps_epoch = 500;
+        int fps_counter = 0;
+        std::chrono::system_clock::time_point fps_last_time;
+    protected:
+        // do nothing in des nodes
+        virtual void dispatch_run() override final;
+        // sample implementation, return nullptr in all des nodes.
+        virtual std::shared_ptr<vp_objects::vp_meta> handle_frame_meta(std::shared_ptr<vp_objects::vp_frame_meta> meta) override; 
+        // sample implementation, return nullptr in all des nodes.
+        virtual std::shared_ptr<vp_objects::vp_meta> handle_control_meta(std::shared_ptr<vp_objects::vp_control_meta> meta) override;
+
+        // protected as it can't be instanstiated directly.        
+        vp_des_node(std::string node_name, int channel_index);
+    public:
+        ~vp_des_node();
+
+        virtual vp_node_type node_type() override;
+
+        int channel_index;
+    };
+}