Enable nvidia-optical-flow-sdk when building opencv4 with cuda

pkgs/development/libraries/nvidia-optical-flow-sdk/default.nix

@@ -0,0 +1,28 @@
+{ stdenv, fetchFromGitHub }:
+
+stdenv.mkDerivation {
+  pname = "nvidia-optical-flow-sdk";
+  version = "1.0";
+
+  src = fetchFromGitHub {
+    owner = "NVIDIA";
+    repo = "NVIDIAOpticalFlowSDK";
+    rev = "79c6cee80a2df9a196f20afd6b598a9810964c32";
+    sha256 = "1y6igwv75v1ynqm7j6la3ky0f15mgnj1jyyak82yvhcsx1aax0a1";
+  };
+
+  # # We only need the header files. The library files are
+  # # in the nvidia_x11 driver.
+  installPhase = ''
+    mkdir -p $out/include
+    cp -R * $out/include
+  '';
+
+  meta = with stdenv.lib; {
+    description = "Nvidia optical flow headers for computing the relative motion of pixels between images";
+    homepage = "https://developer.nvidia.com/opticalflow-sdk";
+    license = licenses.bsd3; # applies to the header files only
+    platforms = platforms.all;
+  };
+}
+

pkgs/development/libraries/opencv/4.x.nix

@@ -15,7 +15,7 @@
 , enableContrib   ? true
 
 , enableCuda      ? (config.cudaSupport or false) &&
-                    stdenv.hostPlatform.isx86_64, cudatoolkit
+                    stdenv.hostPlatform.isx86_64, cudatoolkit, nvidia-optical-flow-sdk
 
 , enableUnfree    ? false
 , enableIpp       ? false
@@ -166,6 +166,7 @@ stdenv.mkDerivation {
   # Also, work around https://github.com/NixOS/nixpkgs/issues/26304 with
   # what appears to be some stray headers in dnn/misc/tensorflow
   # in contrib when generating the Python bindings:
+  patches = lib.optional enableCuda ./cuda_opt_flow.patch;
   postPatch = ''
     sed -i '/Add these standard paths to the search paths for FIND_LIBRARY/,/^\s*$/{d}' CMakeLists.txt
     sed -i -e 's|if len(decls) == 0:|if len(decls) == 0 or "opencv2/" not in hdr:|' ./modules/python/src2/gen2.py
@@ -213,7 +214,7 @@ stdenv.mkDerivation {
     # tesseract & leptonica.
     ++ lib.optionals enableTesseract [ tesseract leptonica ]
     ++ lib.optional enableTbb tbb
-    ++ lib.optional enableCuda cudatoolkit
+    ++ lib.optionals enableCuda [ cudatoolkit nvidia-optical-flow-sdk ]
     ++ lib.optionals stdenv.isDarwin [ bzip2 AVFoundation Cocoa VideoDecodeAcceleration ]
     ++ lib.optionals enableDocs [ doxygen graphviz-nox ];
 
@@ -249,6 +250,7 @@ stdenv.mkDerivation {
     "-DCUDA_FAST_MATH=ON"
     "-DCUDA_HOST_COMPILER=${cudatoolkit.cc}/bin/cc"
     "-DCUDA_NVCC_FLAGS=--expt-relaxed-constexpr"
+    "-DNVIDIA_OPTICAL_FLOW_1_0_HEADERS_PATH=${nvidia-optical-flow-sdk}"
   ] ++ lib.optionals stdenv.isDarwin [
     "-DWITH_OPENCL=OFF"
     "-DWITH_LAPACK=OFF"

pkgs/development/libraries/opencv/cuda_opt_flow.patch

@@ -0,0 +1,26 @@
+diff --git a/opencv_contrib/cudaoptflow/CMakeLists.txt b/opencv_contrib/cudaoptflow/CMakeLists.txt
+index e5b823ab4a..a728060d0b 100644
+--- a/opencv_contrib/cudaoptflow/CMakeLists.txt
++++ b/opencv_contrib/cudaoptflow/CMakeLists.txt
+@@ -11,18 +11,6 @@ ocv_define_module(cudaoptflow opencv_video opencv_optflow opencv_cudaarithm open
+ set(NVIDIA_OPTICAL_FLOW_1_0_HEADERS_COMMIT "79c6cee80a2df9a196f20afd6b598a9810964c32")
+ set(NVIDIA_OPTICAL_FLOW_1_0_HEADERS_MD5 "ca5acedee6cb45d0ec610a6732de5c15")
+ set(NVIDIA_OPTICAL_FLOW_1_0_HEADERS_PATH "${OpenCV_BINARY_DIR}/3rdparty/NVIDIAOpticalFlowSDK_1_0_Headers")
+-ocv_download(FILENAME "${NVIDIA_OPTICAL_FLOW_1_0_HEADERS_COMMIT}.zip"
+-               HASH ${NVIDIA_OPTICAL_FLOW_1_0_HEADERS_MD5}
+-               URL
+-                 "https://github.com/NVIDIA/NVIDIAOpticalFlowSDK/archive/"
+-               DESTINATION_DIR "${NVIDIA_OPTICAL_FLOW_1_0_HEADERS_PATH}"
+-               STATUS NVIDIA_OPTICAL_FLOW_1_0_HEADERS_DOWNLOAD_SUCCESS
+-               ID "NVIDIA_OPTICAL_FLOW"
+-               UNPACK RELATIVE_URL)
+
+-if(NOT NVIDIA_OPTICAL_FLOW_1_0_HEADERS_DOWNLOAD_SUCCESS)
+-  message(STATUS "Failed to download NVIDIA_Optical_Flow_1_0 Headers")
+-else()
+-  add_definitions(-DHAVE_NVIDIA_OPTFLOW=1)
+-  ocv_include_directories(SYSTEM "${NVIDIA_OPTICAL_FLOW_1_0_HEADERS_PATH}/NVIDIAOpticalFlowSDK-${NVIDIA_OPTICAL_FLOW_1_0_HEADERS_COMMIT}")
+-endif()
+\ No newline at end of file
++add_definitions(-DHAVE_NVIDIA_OPTFLOW=1)
++ocv_include_directories(SYSTEM "${NVIDIA_OPTICAL_FLOW_1_0_HEADERS_PATH}")

pkgs/top-level/all-packages.nix

@@ -13585,6 +13585,8 @@ in
 
   nvidia-video-sdk = callPackage ../development/libraries/nvidia-video-sdk { };
 
+  nvidia-optical-flow-sdk = callPackage ../development/libraries/nvidia-optical-flow-sdk { };
+
   nvtop = callPackage ../tools/system/nvtop {
     nvidia_x11 = linuxPackages.nvidia_x11.override { libsOnly = true; };
   };