Merge pull request #20785 from smirnov-alexey:as/oak_backend

GAPI: Add OAK backend

* Initial tests and cmake integration

* Add a public header and change tests

* Stub initial empty template for the OAK backend

* WIP

* WIP

* WIP

* WIP

* Runtime dai hang debug

* Refactoring

* Fix hang and debug frame data

* Fix frame size

* Fix data size issue

* Move test code to sample

* tmp refactoring

* WIP: Code refactoring except for the backend

* WIP: Add non-camera sample

* Fix samples

* Backend refactoring wip

* Backend rework wip

* Backend rework wip

* Remove mat encoder

* Fix namespace

* Minor backend fixes

* Fix hetero sample and refactor backend

* Change linking logic in the backend

* Fix oak sample

* Fix working with ins/outs in OAK island

* Trying to fix nv12 problem

* Make both samples work

* Small refactoring

* Remove meta args

* WIP refactoring kernel API

* Change in/out args API for kernels

* Fix build

* Fix cmake warning

* Partially address review comments

* Partially address review comments

* Address remaining comments

* Add memory ownership

* Change pointer-to-pointer to reference-to-pointer

* Remove unnecessary reference wrappers

* Apply review comments

* Check that graph contains only one OAK island

* Minor refactoring

* Address review comments

modules/gapi/test/oak/gapi_tests_oak.cpp

@@ -0,0 +1,26 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html.
+//
+// Copyright (C) 2021 Intel Corporation
+
+#include "../test_precomp.hpp"
+
+#ifdef HAVE_OAK
+
+#include <opencv2/gapi/oak/oak.hpp>
+
+namespace opencv_test
+{
+
+// FIXME: consider a better solution
+TEST(OAK, Available)
+{
+    cv::GFrame in;
+    auto out = cv::gapi::oak::encode(in, {});
+    auto args = cv::compile_args(cv::gapi::oak::ColorCameraParams{}, cv::gapi::oak::kernels());
+    auto pipeline = cv::GComputation(cv::GIn(in), cv::GOut(out)).compileStreaming(std::move(args));
+}
+} // opencv_test
+
+#endif // HAVE_OAK