opencv: add cvtracker plugin

This adds an object tracker plugin.
Tracker implementations from https://docs.opencv.org/3.4/d0/d0a/classcv_1_1Tracker.html

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2454>

4 files changed, 514 insertions, 2 deletions

diff --git a/ext/opencv/gstcvtracker.cpp b/ext/opencv/gstcvtracker.cpp
new file mode 100644
index 000000000..829d9a2c6
--- /dev/null
+++ b/ext/opencv/gstcvtracker.cpp
@@ -0,0 +1,393 @@
+/*
+ * GStreamer
+ * Copyright (C) 2020 Vivek R <123vivekr@gmail.com>
+ * Copyright (C) 2021 Cesar Fabian Orccon Chipana <cfoch.fabian@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Alternatively, the contents of this file may be used under the
+ * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
+ * which case the following provisions apply instead of the ones
+ * mentioned above:
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+/**
+ * SECTION:element-cvtracker
+ *
+ * Performs object tracking on videos and stores it in video buffer metadata.
+ *
+ * ## Example launch line
+ *
+ * ```
+ * gst-launch-1.0 v4l2src ! videoconvert ! cvtracker box-x=50 box-y=50 box-wdith=50 box-height=50 ! videoconvert ! xvimagesink
+ * ```
+ *
+ * Since: 1.20
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "gstcvtracker.h"
+
+GST_DEBUG_CATEGORY_STATIC (gst_cvtracker_debug);
+#define GST_CAT_DEFAULT gst_cvtracker_debug
+
+#define DEFAULT_PROP_INITIAL_X 50
+#define DEFAULT_PROP_INITIAL_Y 50
+#define DEFAULT_PROP_INITIAL_WIDTH 50
+#define DEFAULT_PROP_INITIAL_HEIGHT 50
+
+enum
+{
+  PROP_0,
+  PROP_INITIAL_X,
+  PROP_INITIAL_Y,
+  PROP_INITIAL_WIDTH,
+  PROP_INITIAL_HEIGHT,
+  PROP_ALGORITHM,
+};
+
+#define GST_OPENCV_TRACKER_ALGORITHM (tracker_algorithm_get_type ())
+
+/**
+ * GstOpenCVTrackerAlgorithm:
+ *
+ * Since: 1.20
+ */
+static GType
+tracker_algorithm_get_type (void)
+{
+  static GType algorithm = 0;
+  static const GEnumValue algorithms[] = {
+    {GST_OPENCV_TRACKER_ALGORITHM_BOOSTING, "the Boosting tracker", "Boosting"},
+    {GST_OPENCV_TRACKER_ALGORITHM_CSRT, "the CSRT tracker", "CSRT"},
+    {GST_OPENCV_TRACKER_ALGORITHM_KCF,
+          "the KCF (Kernelized Correlation Filter) tracker",
+        "KCF"},
+    {GST_OPENCV_TRACKER_ALGORITHM_MEDIANFLOW, "the Median Flow tracker",
+        "MedianFlow"},
+    {GST_OPENCV_TRACKER_ALGORITHM_MIL, "the MIL tracker", "MIL"},
+    {GST_OPENCV_TRACKER_ALGORITHM_MOSSE,
+        "the MOSSE (Minimum Output Sum of Squared Error) tracker", "MOSSE"},
+    {GST_OPENCV_TRACKER_ALGORITHM_TLD,
+          "the TLD (Tracking, learning and detection) tracker",
+        "TLD"},
+    {0, NULL, NULL},
+  };
+
+  if (!algorithm) {
+    algorithm =
+        g_enum_register_static ("GstOpenCVTrackerAlgorithm", algorithms);
+  }
+  return algorithm;
+}
+
+static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("RGB"))
+    );
+
+static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("RGB"))
+    );
+
+G_DEFINE_TYPE_WITH_CODE (GstCVTracker, gst_cvtracker,
+    GST_TYPE_OPENCV_VIDEO_FILTER,
+    GST_DEBUG_CATEGORY_INIT (gst_cvtracker_debug, "cvtracker", 0,
+        "Performs object tracking on videos and stores it in video buffer "
+        "metadata"));
+GST_ELEMENT_REGISTER_DEFINE (cvtracker, "cvtracker", GST_RANK_NONE,
+    GST_TYPE_OPENCV_TRACKER);
+
+static void gst_cvtracker_set_property (GObject * object,
+    guint prop_id, const GValue * value, GParamSpec * pspec);
+static void gst_cvtracker_get_property (GObject * object,
+    guint prop_id, GValue * value, GParamSpec * pspec);
+
+static GstFlowReturn gst_cvtracker_transform_ip (GstOpencvVideoFilter
+    * filter, GstBuffer * buf, cv::Mat img);
+
+static void
+gst_cvtracker_finalize (GObject * obj)
+{
+  GstCVTracker *filter = GST_OPENCV_TRACKER (obj);
+
+  filter->tracker.release ();
+  filter->roi.release ();
+
+  G_OBJECT_CLASS (gst_cvtracker_parent_class)->finalize (obj);
+}
+
+static void
+gst_cvtracker_class_init (GstCVTrackerClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstOpencvVideoFilterClass *gstopencvbasefilter_class;
+  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+
+  gobject_class = (GObjectClass *) klass;
+  gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_cvtracker_finalize);
+  gstopencvbasefilter_class = (GstOpencvVideoFilterClass *) klass;
+
+  gstopencvbasefilter_class->cv_trans_ip_func = gst_cvtracker_transform_ip;
+
+  gobject_class->set_property = gst_cvtracker_set_property;
+  gobject_class->get_property = gst_cvtracker_get_property;
+
+   /*
+    * Tracker API in versions older than OpenCV 4.5.1 worked with a ROI based
+    * on Rect<double>. However newer versions use Rect<int>. Running the same
+    * tracker type on different versions may lead to round up errors.
+    * To avoid inconsistencies from the GStreamer side depending on the OpenCV
+    * version, use integer properties independently on the OpenCV.
+    **/
+  g_object_class_install_property (gobject_class, PROP_INITIAL_X,
+      g_param_spec_uint ("object-initial-x", "Initial X coordinate",
+          "Track object box's initial X coordinate", 0, G_MAXUINT,
+          DEFAULT_PROP_INITIAL_X,
+          (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_INITIAL_Y,
+      g_param_spec_uint ("object-initial-y", "Initial Y coordinate",
+          "Track object box's initial Y coordinate", 0, G_MAXUINT,
+          DEFAULT_PROP_INITIAL_Y,
+          (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_INITIAL_WIDTH,
+      g_param_spec_uint ("object-initial-width", "Object Initial Width",
+          "Track object box's initial width", 0, G_MAXUINT,
+          DEFAULT_PROP_INITIAL_WIDTH,
+          (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_INITIAL_HEIGHT,
+      g_param_spec_uint ("object-initial-height", "Object Initial Height",
+          "Track object box's initial height", 0, G_MAXUINT,
+          DEFAULT_PROP_INITIAL_HEIGHT,
+          (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_ALGORITHM,
+      g_param_spec_enum ("algorithm", "Algorithm",
+          "Algorithm for tracking objects", GST_OPENCV_TRACKER_ALGORITHM,
+          GST_OPENCV_TRACKER_ALGORITHM_MEDIANFLOW,
+          (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  gst_element_class_set_static_metadata (element_class,
+      "cvtracker",
+      "Filter/Effect/Video",
+      "Performs object tracking on videos and stores it in video buffer metadata.",
+      "Vivek R <123vivekr@gmail.com>");
+
+  gst_element_class_add_static_pad_template (element_class, &src_factory);
+  gst_element_class_add_static_pad_template (element_class, &sink_factory);
+
+  gst_type_mark_as_plugin_api (GST_OPENCV_TRACKER_ALGORITHM,
+      (GstPluginAPIFlags) 0);
+}
+
+static void
+gst_cvtracker_init (GstCVTracker * filter)
+{
+  filter->x = DEFAULT_PROP_INITIAL_X;
+  filter->y = DEFAULT_PROP_INITIAL_Y;
+  filter->width = DEFAULT_PROP_INITIAL_WIDTH;
+  filter->height = DEFAULT_PROP_INITIAL_HEIGHT;
+#if CV_VERSION_MAJOR == 4 && CV_VERSION_MINOR >= 5 && CV_VERSION_REVISION >= 1
+  filter->tracker = cv::legacy::upgradeTrackingAPI(
+      cv::legacy::TrackerMedianFlow::create());
+#else
+  filter->tracker = cv::TrackerMedianFlow::create();
+#endif
+  filter->post_debug_info = TRUE;
+
+  gst_opencv_video_filter_set_in_place (GST_OPENCV_VIDEO_FILTER_CAST (filter),
+      TRUE);
+  filter->algorithm = GST_OPENCV_TRACKER_ALGORITHM_MEDIANFLOW;
+}
+
+static void
+gst_cvtracker_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstCVTracker *filter = GST_OPENCV_TRACKER (object);
+
+  switch (prop_id) {
+    case PROP_INITIAL_X:
+      filter->x = g_value_get_uint (value);
+      break;
+    case PROP_INITIAL_Y:
+      filter->y = g_value_get_uint (value);
+      break;
+    case PROP_INITIAL_WIDTH:
+      filter->width = g_value_get_uint (value);
+      break;
+    case PROP_INITIAL_HEIGHT:
+      filter->height = g_value_get_uint (value);
+      break;
+    case PROP_ALGORITHM:
+      filter->algorithm = g_value_get_enum (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+create_cvtracker (GstCVTracker * filter)
+{
+  switch (filter->algorithm) {
+    case GST_OPENCV_TRACKER_ALGORITHM_BOOSTING:
+#if CV_VERSION_MAJOR == 4 && CV_VERSION_MINOR >= 5 && CV_VERSION_REVISION >= 1
+      filter->tracker = cv::legacy::upgradeTrackingAPI(
+          cv::legacy::TrackerBoosting::create());
+#else
+      filter->tracker = cv::TrackerBoosting::create();
+#endif
+      break;
+    case GST_OPENCV_TRACKER_ALGORITHM_CSRT:
+      filter->tracker = cv::TrackerCSRT::create ();
+      break;
+    case GST_OPENCV_TRACKER_ALGORITHM_KCF:
+      filter->tracker = cv::TrackerKCF::create ();
+      break;
+    case GST_OPENCV_TRACKER_ALGORITHM_MEDIANFLOW:
+#if CV_VERSION_MAJOR == 4 && CV_VERSION_MINOR >= 5 && CV_VERSION_REVISION >= 1
+      filter->tracker = cv::legacy::upgradeTrackingAPI(
+          cv::legacy::TrackerMedianFlow::create());
+#else
+      filter->tracker = cv::TrackerMedianFlow::create();
+#endif
+      break;
+    case GST_OPENCV_TRACKER_ALGORITHM_MIL:
+      filter->tracker = cv::TrackerMIL::create ();
+      break;
+    case GST_OPENCV_TRACKER_ALGORITHM_MOSSE:
+#if CV_VERSION_MAJOR == 4 && CV_VERSION_MINOR >= 5 && CV_VERSION_REVISION >= 1
+      filter->tracker = cv::legacy::upgradeTrackingAPI(
+          cv::legacy::TrackerMOSSE::create());
+#else
+      filter->tracker = cv::TrackerMOSSE::create ();
+#endif
+      break;
+    case GST_OPENCV_TRACKER_ALGORITHM_TLD:
+#if CV_VERSION_MAJOR == 4 && CV_VERSION_MINOR >= 5 && CV_VERSION_REVISION >= 1
+      filter->tracker = cv::legacy::upgradeTrackingAPI(
+          cv::legacy::TrackerTLD::create());
+#else
+      filter->tracker = cv::TrackerTLD::create();
+#endif
+      break;
+  }
+}
+
+static void
+gst_cvtracker_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec)
+{
+  GstCVTracker *filter = GST_OPENCV_TRACKER (object);
+
+  switch (prop_id) {
+    case PROP_INITIAL_X:
+      g_value_set_uint (value, filter->x);
+      break;
+    case PROP_INITIAL_Y:
+      g_value_set_uint (value, filter->y);
+      break;
+    case PROP_INITIAL_WIDTH:
+      g_value_set_uint (value, filter->width);
+      break;
+    case PROP_INITIAL_HEIGHT:
+      g_value_set_uint (value, filter->height);
+      break;
+    case PROP_ALGORITHM:
+      g_value_set_enum (value, filter->algorithm);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static GstFlowReturn
+gst_cvtracker_transform_ip (GstOpencvVideoFilter * base,
+    GstBuffer * buf, cv::Mat img)
+{
+  GstCVTracker *filter = GST_OPENCV_TRACKER (base);
+  GstStructure *s;
+  GstMessage *msg;
+
+  if (filter->roi.empty ()) {
+#if CV_VERSION_MAJOR == 4 && CV_VERSION_MINOR >= 5 && CV_VERSION_REVISION >= 1
+    filter->roi = new (cv::Rect);
+#else
+    filter->roi = new (cv::Rect2d);
+#endif
+    filter->roi->x = filter->x;
+    filter->roi->y = filter->y;
+    filter->roi->width = filter->width;
+    filter->roi->height = filter->height;
+    create_cvtracker (filter);
+    filter->tracker->init (img, *filter->roi);
+  } else if (filter->tracker->update (img, *filter->roi)) {
+#if (!(CV_VERSION_MAJOR == 4 && CV_VERSION_MINOR >= 5 && CV_VERSION_REVISION >= 1))
+    /* Round values to avoid inconsistencies depending on the OpenCV version. */
+    filter->roi->x = cvRound (filter->roi->x);
+    filter->roi->y = cvRound (filter->roi->y);
+    filter->roi->width = cvRound (filter->roi->width);
+    filter->roi->height = cvRound (filter->roi->height);
+#endif
+    s = gst_structure_new ("object",
+        "x", G_TYPE_UINT, (guint) filter->roi->x,
+        "y", G_TYPE_UINT, (guint) filter->roi->y,
+        "width", G_TYPE_UINT, (guint) filter->roi->width,
+        "height", G_TYPE_UINT, (guint) filter->roi->height, NULL);
+    msg = gst_message_new_element (GST_OBJECT (filter), s);
+    gst_buffer_add_video_region_of_interest_meta (buf, "object",
+        filter->roi->x, filter->roi->y, filter->roi->width,
+        filter->roi->height);
+    gst_element_post_message (GST_ELEMENT (filter), msg);
+    if (!(filter->post_debug_info))
+      filter->post_debug_info = TRUE;
+  } else if (filter->post_debug_info) {
+    GST_DEBUG_OBJECT (filter, "tracker lost");
+    filter->post_debug_info = FALSE;
+  }
+
+  return GST_FLOW_OK;
+}
diff --git a/ext/opencv/gstcvtracker.h b/ext/opencv/gstcvtracker.h
new file mode 100644
index 000000000..b817c86b8
--- /dev/null
+++ b/ext/opencv/gstcvtracker.h
@@ -0,0 +1,114 @@
+/*
+ * GStreamer
+ * Copyright (C) 2020 Vivek R <123vivekr@gmail.com>
+ * Copyright (C) 2021 Cesar Fabian Orccon Chipana <cfoch.fabian@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Alternatively, the contents of this file may be used under the
+ * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
+ * which case the following provisions apply instead of the ones
+ * mentioned above:
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __GST_CVTRACKER_H__
+#define __GST_CVTRACKER_H__
+
+#include <gst/video/gstvideometa.h>
+#include <gst/opencv/gstopencvvideofilter.h>
+#include <opencv2/core.hpp>
+#include <opencv2/imgproc.hpp>
+#include <opencv2/tracking.hpp>
+#if CV_VERSION_MAJOR == 4 && CV_VERSION_MINOR >= 5 && CV_VERSION_REVISION >= 1
+#include <opencv2/tracking/tracking_legacy.hpp>
+#endif
+
+G_BEGIN_DECLS
+
+/* #defines don't like whitespacey bits */
+#define GST_TYPE_OPENCV_TRACKER \
+  (gst_cvtracker_get_type())
+#define GST_OPENCV_TRACKER(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_OPENCV_TRACKER,GstCVTracker))
+#define GST_OPENCV_TRACKER_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_OPENCV_TRACKER,GstCVTrackerClass))
+#define GST_IS_OPENCV_TRACKER(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_OPENCV_TRACKER))
+#define GST_IS_OPENCV_TRACKER_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_OPENCV_TRACKER))
+
+typedef struct _GstCVTracker  GstCVTracker;
+typedef struct _GstCVTrackerClass GstCVTrackerClass;
+
+struct _GstCVTracker
+{
+  GstOpencvVideoFilter element;
+
+  guint x;
+  guint y;
+  guint width;
+  guint height;
+  gint algorithm;
+  gboolean post_debug_info;
+
+  cv::Ptr<cv::Tracker> tracker;
+#if CV_VERSION_MAJOR == 4 && CV_VERSION_MINOR >= 5 && CV_VERSION_REVISION >= 1
+  cv::Ptr<cv::Rect> roi;
+#else
+  cv::Ptr<cv::Rect2d> roi;
+#endif
+};
+
+typedef enum {
+  GST_OPENCV_TRACKER_ALGORITHM_BOOSTING,
+  GST_OPENCV_TRACKER_ALGORITHM_CSRT,
+  GST_OPENCV_TRACKER_ALGORITHM_KCF,
+  GST_OPENCV_TRACKER_ALGORITHM_MEDIANFLOW,
+  GST_OPENCV_TRACKER_ALGORITHM_MIL,
+  GST_OPENCV_TRACKER_ALGORITHM_MOSSE,
+  GST_OPENCV_TRACKER_ALGORITHM_TLD,
+} GstOpenCVTrackerAlgorithm;
+
+struct _GstCVTrackerClass
+{
+  GstOpencvVideoFilterClass parent_class;
+};
+
+GType gst_cvtracker_get_type (void);
+
+GST_ELEMENT_REGISTER_DECLARE (cvtracker);
+
+G_END_DECLS
+
+#endif /* __GST_CVTRACKER_H__ */
diff --git a/ext/opencv/gstopencv.cpp b/ext/opencv/gstopencv.cpp
index aee54c35b..5407a5a99 100644
--- a/ext/opencv/gstopencv.cpp
+++ b/ext/opencv/gstopencv.cpp
@@ -44,6 +44,7 @@
 #include "gstdewarp.h"
 #include "gstcameracalibrate.h"
 #include "gstcameraundistort.h"
+#include "gstcvtracker.h"
 
 
 static gboolean
@@ -72,6 +73,7 @@ plugin_init (GstPlugin * plugin)
   ret |= GST_ELEMENT_REGISTER (dewarp, plugin);
   ret |= GST_ELEMENT_REGISTER (cameracalibrate, plugin);
   ret |= GST_ELEMENT_REGISTER (cameraundistort, plugin);
+  ret |= GST_ELEMENT_REGISTER (cvtracker, plugin);
 
   return ret;
 }
diff --git a/ext/opencv/meson.build b/ext/opencv/meson.build
index f69ea5966..b0bd54e80 100644
--- a/ext/opencv/meson.build
+++ b/ext/opencv/meson.build
@@ -30,7 +30,8 @@ gstopencv_sources = [
   'camerautils.cpp',
   'cameraevent.cpp',
   'gstcameracalibrate.cpp',
-  'gstcameraundistort.cpp'
+  'gstcameraundistort.cpp',
+  'gstcvtracker.cpp'
 ]
 
 libopencv_headers = [
@@ -41,6 +42,7 @@ libopencv_headers = [
   'opencv2/objdetect.hpp',
   'opencv2/opencv.hpp',
   'opencv2/video.hpp',
+  'opencv2/tracking.hpp',
 ]
 
 libopencv4_headers = [
@@ -51,6 +53,7 @@ libopencv4_headers = [
   'opencv4/opencv2/objdetect.hpp',
   'opencv4/opencv2/opencv.hpp',
   'opencv4/opencv2/video.hpp',
+  'opencv4/opencv2/tracking.hpp',
 ]
 
 gstopencv_cargs = ['-DGST_HAAR_CASCADES_DIR="@0@"']
@@ -115,7 +118,7 @@ if opencv_found
   gstopencv = library('gstopencv',
     gstopencv_sources,
     cpp_args : gst_plugins_bad_args + gstopencv_cargs + [ '-DGST_USE_UNSTABLE_API' ],
-    link_args : noseh_link_args,
+    link_args : [noseh_link_args, '-lopencv_tracking'],
     include_directories : [configinc, libsinc],
     dependencies : [gstbase_dep, gstvideo_dep, opencv_dep, gstopencv_dep],
     install : true,