Fix NV12 crash issue when recreate camera object

modules/ANSCV/ANSRTSP.h

@@ -16,6 +16,8 @@
 #include <opencv2/imgproc.hpp>
 #include <opencv2/highgui.hpp>
 #include <opencv2/opencv.hpp>
+#include <atomic>
+#include <condition_variable>
 
 namespace ANSCENTER
 {
@@ -37,7 +39,36 @@ namespace ANSCENTER
 		int64_t  _pts;
 		bool	 _isPlaying;
 		std::recursive_mutex		_mutex;
+
+		// --- Per-client inference guard ---
+		// Tracks how many GPU frames from this client are currently in-flight
+		// (grabbed by GetRTSPCVImage but not yet released after inference).
+		// Destroy() waits for this to reach 0 before freeing NVDEC surfaces,
+		// preventing the use-after-free crash when LabVIEW stops a camera
+		// while AI inference is still reading CUDA device pointers.
+		std::atomic<int>            _inFlightFrames{0};
+		std::condition_variable_any _inFlightDone;
 	public:
+		void IncrementInFlight() { _inFlightFrames.fetch_add(1, std::memory_order_acq_rel); }
+		void DecrementInFlight() {
+			if (_inFlightFrames.fetch_sub(1, std::memory_order_acq_rel) <= 1) {
+				_inFlightDone.notify_all();
+			}
+		}
+		// Atomically check _isPlaying AND increment _inFlightFrames under the
+		// same mutex.  Returns true if the caller may proceed to access CUDA
+		// resources (GetCudaHWFrame + D2D copy).  Returns false if the player
+		// is stopping/reconnecting — caller must NOT touch CUDA resources.
+		//
+		// This closes the race window where Reconnect() sets _isPlaying=false
+		// and calls close() while GetRTSPCVImage is between GetCudaHWFrame()
+		// and the D2D copy in gpu_frame_attach_cuda().
+		bool TryIncrementInFlight() {
+			std::lock_guard<std::recursive_mutex> lock(_mutex);
+			if (!_isPlaying) return false;
+			_inFlightFrames.fetch_add(1, std::memory_order_acq_rel);
+			return true;
+		}
 		ANSRTSPClient();
 		~ANSRTSPClient() noexcept;
 		[[nodiscard]] bool Init(std::string licenseKey, std::string url);