first commit

nodes/vp_des_node.cpp

@@ -0,0 +1,60 @@
+
+#include "vp_des_node.h"
+
+
+namespace vp_nodes {
+
+        
+    vp_des_node::vp_des_node(std::string node_name, int channel_index): 
+                            vp_node(node_name), channel_index(channel_index) {
+        stream_status.channel_index = channel_index;
+    }
+    
+    vp_des_node::~vp_des_node() {
+
+    }
+
+    // do nothing in des nodes
+    void vp_des_node::dispatch_run() {
+        // dispatch thread terminates immediately in all des nodes
+    }
+
+    // it is the end point of stream(frame meta) in pipe, this method MUST be called at the end of handle_frame_meta in derived class.
+    // using 'return vp_des_node::handle_frame_meta(...);'
+    std::shared_ptr<vp_objects::vp_meta> vp_des_node::handle_frame_meta(std::shared_ptr<vp_objects::vp_frame_meta> meta) {
+        // update cache of stream status
+        stream_status.frame_index = meta->frame_index;
+        stream_status.width = meta->frame.size().width;
+        stream_status.height = meta->frame.size().height;
+        stream_status.direction = to_string();
+
+        // calculate the duration between now and the time when meta created, which is latency.
+        auto delta_time = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now() - meta->create_time);
+        stream_status.latency = delta_time.count();
+
+        // update fps if need
+        fps_counter++;
+        delta_time = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now() - fps_last_time);
+        if (delta_time.count() >= fps_epoch) {        
+            stream_status.fps = fps_counter * 1000.0 / delta_time.count();
+            fps_counter = 0;
+            fps_last_time = std::chrono::system_clock::now();
+        }
+
+        // activate the stream status hooker if need
+        invoke_stream_status_hooker(node_name, stream_status);
+        
+        return nullptr;
+    }
+    
+    // it is the end point of control meta in pipe, this method MUST be called at the end of handle_control_meta in derived class.
+    // using 'return vp_des_node::handle_control_meta(...);'
+    std::shared_ptr<vp_objects::vp_meta> vp_des_node::handle_control_meta(std::shared_ptr<vp_objects::vp_control_meta> meta) {
+        // ...
+        return nullptr;
+    }
+
+    vp_node_type vp_des_node::node_type() {
+        return vp_node_type::DES;
+    }
+}