Correctly link against GStreamer

Video is still not being displayed, for some reason

CMakeLists.txt

 cmake_minimum_required(VERSION 3.2)
 
-project(QGroundControl LANGUAGES CXX)
+project(QGroundControl LANGUAGES C CXX)
 
 set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug;Release;RelWithDebInfo;MinSizeRel;Coverage")
 
@@ -58,6 +58,16 @@ if (CCACHE AND CCACHE_PROGRAM AND NOT DEFINED ENV{CCACHE_DISABLE})
 	set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE "${CCACHE_PROGRAM}")
 endif()
 
+
+#=============================================================================
+# GStreamer
+#
+find_package(PkgConfig)
+pkg_check_modules(GST
+    gstreamer-1.0>=1.14
+    gstreamer-video-1.0>=1.14
+)
+
 #=============================================================================
 # Qt5
 #
@@ -73,6 +83,7 @@ find_package(Qt5 ${QT_VERSION}
 		Positioning
 		Quick
 		QuickWidgets
+		OpenGL
 		Sql
 		Svg
 		Test

src/VideoStreaming/CMakeLists.txt

+if (GST_FOUND)
+    include_directories(
+        ${GST_INCLUDE_DIRS}
+        gstqtvideosink/utils/
+        )
 
-set(EXTRA_SRC)
-if(VIDEO)
-	list(APPEND EXTRA_SRC
-		gstqtvideosink/delegates/basedelegate.cpp
-		gstqtvideosink/delegates/qtquick2videosinkdelegate.cpp
-		gstqtvideosink/delegates/qtvideosinkdelegate.cpp
-		gstqtvideosink/delegates/qwidgetvideosinkdelegate.cpp
-		gstqtvideosink/gstqtglvideosink.cpp
-		gstqtvideosink/gstqtglvideosinkbase.cpp
-		gstqtvideosink/gstqtquick2videosink.cpp
-		gstqtvideosink/gstqtvideosink.cpp
-		gstqtvideosink/gstqtvideosinkbase.cpp
-		gstqtvideosink/gstqtvideosinkplugin.cpp
-		gstqtvideosink/gstqwidgetvideosink.cpp
-		gstqtvideosink/painters/genericsurfacepainter.cpp
-		gstqtvideosink/painters/openglsurfacepainter.cpp
-		gstqtvideosink/painters/videomaterial.cpp
-		gstqtvideosink/painters/videonode.cpp
-		gstqtvideosink/utils/bufferformat.cpp
-		gstqtvideosink/utils/utils.cpp
-	)
-endif()
-
-add_library(VideoStreaming
-	VideoItem.cc
-	VideoReceiver.cc
-	VideoStreaming.cc
-	VideoSurface.cc
-	SubtitleWriter.cc
-	${EXTRA_SRC}
-)
+    set(EXTRA_SRC
+        gstqtvideosink/delegates/basedelegate.cpp
+        gstqtvideosink/delegates/qtquick2videosinkdelegate.cpp
+        gstqtvideosink/delegates/qtvideosinkdelegate.cpp
+        gstqtvideosink/delegates/qwidgetvideosinkdelegate.cpp
+        gstqtvideosink/gstqtglvideosink.cpp
+        gstqtvideosink/gstqtglvideosinkbase.cpp
+        gstqtvideosink/gstqtquick2videosink.cpp
+        gstqtvideosink/gstqtvideosink.cpp
+        gstqtvideosink/gstqtvideosinkbase.cpp
+        gstqtvideosink/gstqtvideosinkplugin.cpp
+        gstqtvideosink/gstqwidgetvideosink.cpp
+        gstqtvideosink/gstqtvideosinkmarshal.c
+        gstqtvideosink/painters/genericsurfacepainter.cpp
+        gstqtvideosink/painters/openglsurfacepainter.cpp
+        gstqtvideosink/painters/videomaterial.cpp
+        gstqtvideosink/painters/videonode.cpp
+        gstqtvideosink/utils/bufferformat.cpp
+        gstqtvideosink/utils/utils.cpp
+    )
 
-target_link_libraries(VideoStreaming
-	PUBLIC
-		qgc
+    add_library(VideoStreaming
+        VideoItem.cc
+        VideoReceiver.cc
+        VideoStreaming.cc
+        VideoSurface.cc
+        SubtitleWriter.cc
+        ${EXTRA_SRC}
+    )
 
-		Qt5::Multimedia
-)
+    target_link_libraries(VideoStreaming
+        PUBLIC
+            qgc
+            Qt5::Multimedia
+            Qt5::OpenGL
+            ${GST_LIBRARIES}
+    )
 
-target_include_directories(VideoStreaming INTERFACE ${CMAKE_CURRENT_SOURCE_DIR})
+    target_include_directories(VideoStreaming INTERFACE ${CMAKE_CURRENT_SOURCE_DIR})
+endif()