first commit

nodes/vp_stream_info_hookable.h

@@ -0,0 +1,46 @@
+#pragma once
+
+#include <functional>
+#include <mutex>
+#include <string>
+#include <memory>
+
+namespace vp_nodes {
+    // stream info created by src nodes.
+    struct vp_stream_info {
+        int channel_index = -1;   // channel index
+        int original_fps = 0;     // original fps of stream
+        int original_width = 0;   // width of resolution
+        int original_height = 0;  // height of resolution
+        std::string uri = "";     // uri of stream
+    };
+    
+    // callback when stream info changed, happens in src nodes. MUST not be blocked.
+    typedef std::function<void(std::string, vp_stream_info)> vp_stream_info_hooker;
+
+    // allow hookers attached to the pipe (src nodes specifically), hookers get notified when stream info changed.
+    // this class is inherited by vp_src_node only.
+    class vp_stream_info_hookable
+    {
+    private:
+        /* data */
+    protected:
+        std::mutex stream_info_hooker_lock;
+        vp_stream_info_hooker stream_info_hooker;
+    public:
+        vp_stream_info_hookable(/* args */) {}
+        ~vp_stream_info_hookable() {}
+
+        void set_stream_info_hooker(vp_stream_info_hooker stream_info_hooker) {
+            std::lock_guard<std::mutex> guard(stream_info_hooker_lock);
+            this->stream_info_hooker = stream_info_hooker;
+        }
+
+        void invoke_stream_info_hooker(std::string node_name, vp_stream_info stream_info) {
+            std::lock_guard<std::mutex> guard(stream_info_hooker_lock);
+            if (this->stream_info_hooker) {
+                this->stream_info_hooker(node_name, stream_info);
+            }
+        }
+    };
+}