PNG writer

apps/LoopThroughWithOpenGLCompositing/gl/OpenGLDeckLinkBridge.h

@@ -16,6 +16,7 @@ class OpenGLDeckLinkBridge
 {
 public:
 	using RenderEffectCallback = std::function<void()>;
+	using OutputReadyCallback = std::function<void()>;
 	using PaintCallback = std::function<void()>;
 
 	OpenGLDeckLinkBridge(
@@ -26,6 +27,7 @@ public:
 		HDC hdc,
 		HGLRC hglrc,
 		RenderEffectCallback renderEffect,
+		OutputReadyCallback outputReady,
 		PaintCallback paint);
 
 	void VideoFrameArrived(IDeckLinkVideoInputFrame* inputFrame, bool hasNoInputSource);
@@ -41,6 +43,7 @@ private:
 	HDC mHdc;
 	HGLRC mHglrc;
 	RenderEffectCallback mRenderEffect;
+	OutputReadyCallback mOutputReady;
 	PaintCallback mPaint;
 	std::chrono::steady_clock::time_point mLastPlayoutCompletionTime;
 	double mCompletionIntervalMilliseconds = 0.0;