From 53c0189ed7efe52ad65c38cac04181155e320ca8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Peter=20W=C3=BCrtz?= <pwuertz@gmail.com>
Date: Tue, 4 Feb 2020 18:25:48 +0100
Subject: [PATCH] Allow access to CUDA memory and stream pointers for
 interoperability.

---
 modules/core/include/opencv2/core/cuda.hpp     | 6 ++++++
 modules/core/include/opencv2/core/cuda.inl.hpp | 6 ++++++
 modules/core/src/cuda_stream.cpp               | 9 +++++++++
 modules/python/test/test_cuda.py               | 8 ++++++++
 4 files changed, 29 insertions(+)

diff --git a/modules/core/include/opencv2/core/cuda.hpp b/modules/core/include/opencv2/core/cuda.hpp
index 99819d75cc..5fa09682e3 100644
--- a/modules/core/include/opencv2/core/cuda.hpp
+++ b/modules/core/include/opencv2/core/cuda.hpp
@@ -305,6 +305,9 @@ public:
     //! returns true if GpuMat data is NULL
     CV_WRAP bool empty() const;
 
+    // returns pointer to cuda memory
+    CV_WRAP void* cudaPtr() const;
+
     //! internal use method: updates the continuity flag
     CV_WRAP void updateContinuityFlag();
 
@@ -681,6 +684,9 @@ public:
     //! returns true if stream object is not default (!= 0)
     operator bool_type() const;
 
+    //! return Pointer to CUDA stream
+    CV_WRAP void* cudaPtr() const;
+
     class Impl;
 
 private:
diff --git a/modules/core/include/opencv2/core/cuda.inl.hpp b/modules/core/include/opencv2/core/cuda.inl.hpp
index 35ae2e49d7..30fc0aee22 100644
--- a/modules/core/include/opencv2/core/cuda.inl.hpp
+++ b/modules/core/include/opencv2/core/cuda.inl.hpp
@@ -343,6 +343,12 @@ bool GpuMat::empty() const
     return data == 0;
 }
 
+inline
+void* GpuMat::cudaPtr() const
+{
+    return data;
+}
+
 static inline
 GpuMat createContinuous(int rows, int cols, int type)
 {
diff --git a/modules/core/src/cuda_stream.cpp b/modules/core/src/cuda_stream.cpp
index 79d7477220..5fb873a369 100644
--- a/modules/core/src/cuda_stream.cpp
+++ b/modules/core/src/cuda_stream.cpp
@@ -535,6 +535,15 @@ Stream& cv::cuda::Stream::Null()
 #endif
 }
 
+void* cv::cuda::Stream::cudaPtr() const
+{
+#ifndef HAVE_CUDA
+    return nullptr;
+#else
+    return impl_->stream;
+#endif
+}
+
 cv::cuda::Stream::operator bool_type() const
 {
 #ifndef HAVE_CUDA
diff --git a/modules/python/test/test_cuda.py b/modules/python/test/test_cuda.py
index 5c4d9606dd..8eba9076a2 100644
--- a/modules/python/test/test_cuda.py
+++ b/modules/python/test/test_cuda.py
@@ -26,5 +26,13 @@ class cuda_test(NewOpenCVTests):
 
         self.assertTrue(np.allclose(cuMat.download(), npMat))
 
+    def test_cuda_interop(self):
+        npMat = (np.random.random((128, 128, 3)) * 255).astype(np.uint8)
+        cuMat = cv.cuda_GpuMat()
+        cuMat.upload(npMat)
+        self.assertTrue(cuMat.cudaPtr() != 0)
+        stream = cv.cuda_Stream()
+        self.assertTrue(stream.cudaPtr() != 0)
+
 if __name__ == '__main__':
     NewOpenCVTests.bootstrap()