t/fm: Add simple FrameMat that wraps a cv::Mat

doc/changes/auxiliary/mr.825.md

@@ -0,0 +1,2 @@
+t/fm: Add simple FrameMat that wraps a cv::Mat, this allows us to easily pass
+cv::Mat's around without the C code needing to know about OpenCV.

src/xrt/auxiliary/CMakeLists.txt

@@ -97,6 +97,8 @@ if(XRT_HAVE_OPENCV)
 		tracking/t_debug_hsv_picker.cpp
 		tracking/t_debug_hsv_viewer.cpp
 		tracking/t_file.cpp
+		tracking/t_frame_cv_mat_wrapper.cpp
+		tracking/t_frame_cv_mat_wrapper.hpp
 		tracking/t_fusion.hpp
 		tracking/t_helper_debug_sink.hpp
 		tracking/t_hsv_filter.c

src/xrt/auxiliary/meson.build

@@ -205,6 +205,8 @@ if build_tracking
 		'tracking/t_debug_hsv_picker.cpp',
 		'tracking/t_debug_hsv_viewer.cpp',
 		'tracking/t_file.cpp',
+		'tracking/t_frame_cv_mat_wrapper.cpp',
+		'tracking/t_frame_cv_mat_wrapper.hpp',
 		'tracking/t_fusion.hpp',
 		'tracking/t_helper_debug_sink.hpp',
 		'tracking/t_hsv_filter.c',

src/xrt/auxiliary/tracking/t_frame_cv_mat_wrapper.cpp

@@ -0,0 +1,116 @@
+// Copyright 2021, Collabora, Ltd.
+// SPDX-License-Identifier: BSL-1.0
+/*!
+ * @file
+ * @brief  Simple @ref xrt_frame wrapper around a @ref cv::Mat.
+ * @author Jakob Bornecrantz <jakob@collabora.com>
+ * @ingroup aux_tracking
+ */
+
+#include "util/u_format.h"
+
+#include "tracking/t_frame_cv_mat_wrapper.hpp"
+
+
+namespace xrt::auxiliary::tracking {
+
+
+/*
+ *
+ * C functions.
+ *
+ */
+
+extern "C" void
+frame_mat_destroy(struct xrt_frame *xf)
+{
+	FrameMat *fm = (FrameMat *)xf;
+	delete fm;
+}
+
+
+/*
+ *
+ * Member functions
+ *
+ */
+
+void
+FrameMat::fillInFields(cv::Mat mat, xrt_format format, const Params &params)
+{
+	uint32_t width = (uint32_t)mat.cols;
+	uint32_t height = (uint32_t)mat.rows;
+	size_t stride = mat.step[0];
+	size_t size = stride * height;
+
+	this->matrix = mat;
+
+	// Main wrapping of cv::Mat by frame.
+	xrt_frame &frame = this->frame;
+	frame.reference.count = 1;
+	frame.destroy = frame_mat_destroy;
+	frame.data = mat.ptr<uint8_t>();
+	frame.format = format;
+	frame.width = width;
+	frame.height = height;
+	frame.stride = stride;
+	frame.size = size;
+
+	// Params
+	frame.timestamp = params.timestamp_ns;
+	frame.stereo_format = params.stereo_format;
+}
+
+FrameMat::~FrameMat()
+{
+	// Noop
+}
+
+FrameMat::FrameMat()
+{
+	// Noop
+}
+
+
+/*
+ *
+ * Static functions.
+ *
+ */
+
+void
+FrameMat::wrapR8G8B8(cv::Mat mat, xrt_frame **fm_out, const Params /*&&?*/ params)
+{
+	assert(mat.channels() == 3);
+	assert(mat.type() == CV_8UC3);
+
+
+	FrameMat *fm = new FrameMat();
+	fm->fillInFields(mat, XRT_FORMAT_R8G8B8, params);
+
+	// Unreference any old frames.
+	xrt_frame_reference(fm_out, NULL);
+
+	// Already has a ref count of one.
+	*fm_out = &fm->frame;
+}
+
+void
+FrameMat::wrapL8(cv::Mat mat, xrt_frame **fm_out, const Params /*&&?*/ params)
+{
+	assert(mat.channels() == 1);
+	assert(mat.type() == CV_8UC1);
+
+
+	FrameMat *fm = new FrameMat();
+	fm->fillInFields(mat, XRT_FORMAT_L8, params);
+
+	// Unreference any old frames.
+	xrt_frame_reference(fm_out, NULL);
+
+	// Already has a ref count of one.
+	*fm_out = &fm->frame;
+}
+
+
+} // namespace xrt::auxiliary::tracking

src/xrt/auxiliary/tracking/t_frame_cv_mat_wrapper.hpp

@@ -0,0 +1,70 @@
+// Copyright 2021, Collabora, Ltd.
+// SPDX-License-Identifier: BSL-1.0
+/*!
+ * @file
+ * @brief  Simple @ref xrt_frame wrapper around a @ref cv::Mat.
+ * @author Jakob Bornecrantz <jakob@collabora.com>
+ * @ingroup aux_tracking
+ */
+
+#include "xrt/xrt_frame.h"
+
+#include <opencv2/opencv.hpp>
+
+
+namespace xrt::auxiliary::tracking {
+
+
+class FrameMat
+{
+public:
+	/*!
+	 * Additional optional parameters for frame creation.
+	 */
+	class Params
+	{
+	public:
+		enum xrt_stereo_format stereo_format;
+		uint64_t timestamp_ns;
+	};
+
+
+public:
+	// Exposed to the C api.
+	struct xrt_frame frame = {};
+
+	// The @ref cv::Mat that holds the data.
+	cv::Mat matrix = cv::Mat();
+
+
+public:
+	/*!
+	 * Only public due to C needed to destroy it.
+	 */
+	~FrameMat();
+
+	/*!
+	 * Wraps the given @ref cv::Mat assuming it's a 24bit RGB format matrix, the pointer pointed to by @ref xf_ptr
+	 * will have it's reference updated.
+	 */
+	static void
+	wrapR8G8B8(cv::Mat mat, xrt_frame **xf_ptr, const Params /*&&?*/ params = {});
+
+	/*!
+	 * Wraps the given @ref cv::Mat assuming it's a 8bit format matrix, the pointer pointed to by @ref xf_ptr will
+	 * have it's reference updated.
+	 */
+	static void
+	wrapL8(cv::Mat mat, xrt_frame **xf_ptr, const Params /*&&?*/ params = {});
+
+
+private:
+	FrameMat();
+
+	void
+	fillInFields(cv::Mat mat, xrt_format format, const Params &params);
+};
+
+
+
+} // namespace xrt::auxiliary::tracking