Video: switch every platform to videoconvert→appsink rendering

Drop the vendored qml6glsink and qml6d3d11sink modules (and the
gst-plugins-good / gst-plugins-bad source downloads they required) and
funnel all GStreamer rendering through a single videoconvert→appsink →
GstAppSinkAdapter → QVideoSink → QML VideoOutput chain. Qt picks the
native RHI backend (Metal / Vulkan / D3D11 / OpenGL), so QGCApplication
no longer probes for an OpenGL context or forces a graphics API.

qgcvideosinkbin loses the d3d11sink and glsinkbin fallbacks plus the
widget / aspect-ratio properties they exposed. GStreamer.cc drops the
qml6 / qt6d3d11 / opengl static plugin registrations and verifies only
appsink / qgc / coreelements; the iOS xcframework no longer needs the
opengl plugin filter. VideoManager removes gstreamerD3D11Sink and
gstreamerAppleSink (the QML side now picks one VideoOutput component
unconditionally), and FlightDisplayViewMetal.qml is renamed to
FlightDisplayViewVideoOutput.qml to reflect the universal path.

Author: HTRamsey

cmake/find-modules/FindGStreamer.cmake

@@ -33,8 +33,20 @@ Configuration Variables
 
 #]=======================================================================]
 
+# Short-circuit only when every currently-requested component already has a target;
+# otherwise re-run so a later find_package(... COMPONENTS NewOne) can populate the
+# new GStreamer::NewOne target instead of silently inheriting the cached _FOUND.
 if (GStreamer_FOUND)
-    return()
+    set(_gst_all_present TRUE)
+    foreach(_gst_c IN LISTS GStreamer_FIND_COMPONENTS)
+        if (NOT TARGET GStreamer::${_gst_c})
+            set(_gst_all_present FALSE)
+            break()
+        endif()
+    endforeach()
+    if (_gst_all_present)
+        return()
+    endif()
 endif()
 
 if (NOT GStreamer_ROOT_DIR OR NOT EXISTS "${GStreamer_ROOT_DIR}")
@@ -137,8 +149,8 @@ endif()
 # _gst_IGNORED_SYSTEM_LIBRARIES and _gst_SRT_REGEX_PATCH are defined in GStreamerHelpers.cmake
 
 if(PC_GStreamer_FOUND AND (NOT TARGET GStreamer::GStreamer))
-    add_library(GStreamer::GStreamer INTERFACE IMPORTED)
-    add_library(GStreamer::deps INTERFACE IMPORTED)
+    add_library(GStreamer::GStreamer INTERFACE IMPORTED GLOBAL)
+    add_library(GStreamer::deps INTERFACE IMPORTED GLOBAL)
 
     if (GStreamer_USE_STATIC_LIBS)
         _gst_filter_missing_directories(PC_GStreamer_STATIC_INCLUDE_DIRS)

cmake/find-modules/FindQGCGStreamer.cmake

@@ -623,7 +623,6 @@ macro(_qgc_discover_ios_sdk)
         set(GSTREAMER_PLUGIN_PATH "${_xcfw_slice_dir}")
 
         _gst_normalize_and_validate_root()
-        return()
     endif()
 
     # ── Classic .framework path ───────────────────────────────────────────────
@@ -652,11 +651,33 @@ macro(_qgc_discover_ios_sdk)
             endif()
         endforeach()
     endif()
+    # 1.28+ embeds everything in the framework binary — no lib/ subdir exists.
+    if(NOT EXISTS "${GSTREAMER_LIB_PATH}")
+        set(GSTREAMER_LIB_PATH    "${GStreamer_ROOT_DIR}")
+        set(GSTREAMER_PLUGIN_PATH "${GStreamer_ROOT_DIR}")
+    endif()
 
-    _qgc_find_apple_pkg_config(PKG_CONFIG_EXECUTABLE)
-    _gst_configure_pkg_config(
-        LIBDIR "${GSTREAMER_LIB_PATH}/pkgconfig" "${GSTREAMER_PLUGIN_PATH}/pkgconfig"
-    )
+    # When no pkgconfig dir is present the framework is a single fat binary (1.28+
+    # Cerbero layout); reuse the xcframework target-creation path which already handles
+    # this: no pkg-config queries, direct link of the binary, system framework deps.
+    if(NOT EXISTS "${GSTREAMER_LIB_PATH}/pkgconfig")
+        # The framework binary lives at Versions/1.0/<FrameworkName> (= GStreamer_ROOT_DIR/GStreamer).
+        set(GSTREAMER_XCFRAMEWORK_PATH "${GSTREAMER_FRAMEWORK_PATH}")
+        set(GSTREAMER_XCFRAMEWORK_LIB  "${GStreamer_ROOT_DIR}/GStreamer")
+        set(GSTREAMER_INCLUDE_PATH     "${GSTREAMER_FRAMEWORK_PATH}/Headers")
+        # Point synthetic lib/plugin paths at the root so downstream existence checks pass.
+        set(GSTREAMER_LIB_PATH    "${GStreamer_ROOT_DIR}")
+        set(GSTREAMER_PLUGIN_PATH "${GStreamer_ROOT_DIR}")
+        set(GStreamer_USE_XCFRAMEWORK ON)
+        _gst_normalize_and_validate_root()
+    endif()
+
+    if(NOT GStreamer_USE_XCFRAMEWORK)  # xcframework has no .pc files; target already created
+        _qgc_find_apple_pkg_config(PKG_CONFIG_EXECUTABLE)
+        _gst_configure_pkg_config(
+            LIBDIR "${GSTREAMER_LIB_PATH}/pkgconfig" "${GSTREAMER_PLUGIN_PATH}/pkgconfig"
+        )
+    endif()
 endmacro()
 
 # Dispatch to the appropriate platform discovery macro
@@ -756,8 +777,12 @@ if(NOT DEFINED GSTREAMER_EXTRA_DEPS)
     endif()
 endif()
 
+# Default plugin set assumes the videoconvert→appsink rendering path used everywhere.
+# The base opengl / d3d11 plugins are kept because GStreamer auto-plugs gldownload /
+# d3d11download when hardware decoders produce GPU memory.
 if(NOT DEFINED GSTREAMER_PLUGINS)
     set(GSTREAMER_PLUGINS
+        app
         coreelements
         isomp4
         libav
@@ -775,15 +800,12 @@ if(NOT DEFINED GSTREAMER_PLUGINS)
         udp
         videoparsersbad
         vpx
+        # gst >=1.22 split: only the one matching the SDK gets a target; #ifdef in GStreamer.cc picks it.
+        videoconvertscale
+        videoconvert
+        videoscale
     )
-    # Deferred on Linux — actual version may differ from the minimum (see finalization below)
-    if(NOT LINUX)
-        if(GStreamer_FIND_VERSION VERSION_GREATER_EQUAL "1.22")
-            list(APPEND GSTREAMER_PLUGINS videoconvertscale)
-        else()
-            list(APPEND GSTREAMER_PLUGINS videoconvert videoscale)
-        endif()
-    endif()
+    # Deferred for all platforms — GStreamer_VERSION is populated after find_package(GStreamer) below.
     if(ANDROID)
         list(APPEND GSTREAMER_PLUGINS androidmedia dav1d)
     elseif(APPLE)
@@ -840,11 +862,14 @@ if(GStreamer_USE_XCFRAMEWORK)
         target_link_libraries(GStreamer::GStreamer INTERFACE
             GStreamer_static
         )
-        target_include_directories(GStreamer::GStreamer INTERFACE
-            "${GSTREAMER_INCLUDE_PATH}"
-            "${GSTREAMER_INCLUDE_PATH}/gstreamer-1.0"
-            "${GSTREAMER_INCLUDE_PATH}/glib-2.0"
-        )
+        # iOS .framework has flat Headers/; macOS-style installs have the gstreamer-1.0 /
+        # glib-2.0 subdirs. Add only what exists — INTERFACE_INCLUDE_DIRECTORIES is validated.
+        target_include_directories(GStreamer::GStreamer INTERFACE "${GSTREAMER_INCLUDE_PATH}")
+        foreach(_inc_sub IN ITEMS gstreamer-1.0 glib-2.0)
+            if(IS_DIRECTORY "${GSTREAMER_INCLUDE_PATH}/${_inc_sub}")
+                target_include_directories(GStreamer::GStreamer INTERFACE "${GSTREAMER_INCLUDE_PATH}/${_inc_sub}")
+            endif()
+        endforeach()
         # System frameworks required by GStreamer on iOS.
         find_library(_xcfw_foundation     Foundation     REQUIRED)
         find_library(_xcfw_avfoundation   AVFoundation   REQUIRED)
@@ -1052,15 +1077,6 @@ foreach(plugin IN LISTS GSTREAMER_PLUGINS)
     endif()
 endforeach()
 
-if(LINUX AND NOT "videoconvertscale" IN_LIST GSTREAMER_PLUGINS
-        AND NOT "videoconvert" IN_LIST GSTREAMER_PLUGINS)
-    if(GStreamer_VERSION VERSION_GREATER_EQUAL "1.22")
-        list(APPEND GSTREAMER_PLUGINS videoconvertscale)
-    else()
-        list(APPEND GSTREAMER_PLUGINS videoconvert videoscale)
-    endif()
-endif()
-
 if(NOT GStreamer_USE_STATIC_LIBS AND NOT GStreamer_USE_XCFRAMEWORK AND EXISTS "${GSTREAMER_PLUGIN_PATH}")
     set(_gst_missing_plugins)
     if(WIN32)
@@ -1084,7 +1100,18 @@ if(NOT GStreamer_USE_STATIC_LIBS AND NOT GStreamer_USE_XCFRAMEWORK AND EXISTS "$
         endif()
     endforeach()
     list(REMOVE_DUPLICATES _gst_available_basenames)
+    # videoconvert(scale)/videoscale alternate — only one ships per gst version; don't warn on the absent ones.
+    set(_gst_alternate_satisfied FALSE)
+    if("videoconvertscale" IN_LIST _gst_available_basenames
+            OR ("videoconvert" IN_LIST _gst_available_basenames
+                AND "videoscale" IN_LIST _gst_available_basenames))
+        set(_gst_alternate_satisfied TRUE)
+    endif()
     foreach(_plugin IN LISTS GSTREAMER_PLUGINS)
+        if(_gst_alternate_satisfied
+                AND _plugin MATCHES "^(videoconvertscale|videoconvert|videoscale)$")
+            continue()
+        endif()
         if(NOT _plugin IN_LIST _gst_available_basenames)
             list(APPEND _gst_missing_plugins "${_plugin}")
         endif()
@@ -1096,16 +1123,76 @@ if(NOT GStreamer_USE_STATIC_LIBS AND NOT GStreamer_USE_XCFRAMEWORK AND EXISTS "$
     endif()
 endif()
 
-if(GStreamer_VERSION AND TARGET GStreamer::GStreamer)
+if(GStreamer_VERSION)
     string(REGEX MATCH "^([0-9]+)\\.([0-9]+)" _gst_ver_match "${GStreamer_VERSION}")
     if(_gst_ver_match)
-        target_compile_definitions(GStreamer::GStreamer INTERFACE
-            QGC_GST_BUILD_VERSION_MAJOR=${CMAKE_MATCH_1}
-            QGC_GST_BUILD_VERSION_MINOR=${CMAKE_MATCH_2}
-        )
+        # Mobile (iOS/Android) builds consume GStreamerMobile (alias GStreamer::mobile) instead
+        # of GStreamer::GStreamer, so propagate the version defines to whichever exists.
+        foreach(_gst_target IN ITEMS GStreamer::GStreamer GStreamerMobile)
+            if(TARGET ${_gst_target})
+                # target_compile_definitions can't be called on ALIAS targets — resolve first.
+                get_target_property(_gst_aliased ${_gst_target} ALIASED_TARGET)
+                if(_gst_aliased)
+                    set(_gst_real ${_gst_aliased})
+                else()
+                    set(_gst_real ${_gst_target})
+                endif()
+                target_compile_definitions(${_gst_real} INTERFACE
+                    QGC_GST_BUILD_VERSION_MAJOR=${CMAKE_MATCH_1}
+                    QGC_GST_BUILD_VERSION_MINOR=${CMAKE_MATCH_2}
+                )
+            endif()
+        endforeach()
     endif()
 endif()
 
+# GstVideoOrientationMeta is officially in 1.26+, but bundled iOS/Android SDKs sometimes
+# strip it. Feature-test the actual header instead of trusting the version number.
+include(CheckCXXSourceCompiles)
+foreach(_gst_target IN ITEMS GStreamer::GStreamer GStreamerMobile)
+    if(TARGET ${_gst_target})
+        set(CMAKE_REQUIRED_LIBRARIES_BACKUP "${CMAKE_REQUIRED_LIBRARIES}")
+        set(CMAKE_REQUIRED_LIBRARIES ${_gst_target})
+        check_cxx_source_compiles("
+            #include <gst/video/gstvideometa.h>
+            int main() { GstVideoOrientationMeta *m = nullptr; (void)m; return 0; }
+        " QGC_GST_HAS_VIDEO_ORIENTATION_META_${_gst_target})
+        set(CMAKE_REQUIRED_LIBRARIES "${CMAKE_REQUIRED_LIBRARIES_BACKUP}")
+        if(QGC_GST_HAS_VIDEO_ORIENTATION_META_${_gst_target})
+            get_target_property(_gst_aliased ${_gst_target} ALIASED_TARGET)
+            if(_gst_aliased)
+                set(_gst_real ${_gst_aliased})
+            else()
+                set(_gst_real ${_gst_target})
+            endif()
+            target_compile_definitions(${_gst_real} INTERFACE
+                QGC_HAS_GST_VIDEO_ORIENTATION_META=1)
+        endif()
+    endif()
+endforeach()
+
+# Zero-copy DMABuf GPU path (Linux only). Requires gst-allocators and Qt's
+# private QHwVideoBuffer header. Both are detected here and the combined
+# QGC_HAS_GST_DMABUF_GPU_PATH define is exposed to consumers via
+# target_compile_definitions on the QGCGStreamerDmaBufFeature interface target
+# below — the feature consumer picks it up by linking that target.
+if(LINUX)
+    foreach(_gst_target IN ITEMS GStreamer::GStreamer GStreamerMobile)
+        if(TARGET ${_gst_target})
+            set(CMAKE_REQUIRED_LIBRARIES_BACKUP "${CMAKE_REQUIRED_LIBRARIES}")
+            set(CMAKE_REQUIRED_LIBRARIES ${_gst_target})
+            check_cxx_source_compiles("
+                #include <gst/allocators/gstdmabuf.h>
+                int main() { (void)gst_is_dmabuf_memory; return 0; }
+            " QGC_GST_HAS_DMABUF_${_gst_target})
+            set(CMAKE_REQUIRED_LIBRARIES "${CMAKE_REQUIRED_LIBRARIES_BACKUP}")
+            if(QGC_GST_HAS_DMABUF_${_gst_target})
+                set(QGC_GST_HAS_DMABUF TRUE)
+            endif()
+        endif()
+    endforeach()
+endif()
+
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(QGCGStreamer
     REQUIRED_VARS GStreamer_ROOT_DIR GSTREAMER_LIB_PATH GSTREAMER_PLUGIN_PATH

cmake/platform/Apple.cmake

@@ -6,6 +6,11 @@ if(NOT APPLE)
     message(FATAL_ERROR "QGC: Invalid Platform: Apple.cmake included but platform is not Apple")
 endif()
 
+# .mm sources (e.g. GstIOSurfaceVideoBuffer.mm) need OBJCXX rules at root scope so
+# CMAKE_OBJCXX_COMPILE_OBJECT is populated for the QGC target. Done here unconditionally
+# for macOS + iOS rather than relying on a deferred enable_language inside Find modules.
+enable_language(OBJC OBJCXX)
+
 if(CMAKE_GENERATOR STREQUAL "Xcode" AND MACOS)
     # set(CMAKE_XCODE_ATTRIBUTE_DEVELOPMENT_TEAM
     # set(CMAKE_XCODE_ATTRIBUTE_CODE_SIGN_STYLE
@@ -58,7 +63,6 @@ if(MACOS)
     message(STATUS "QGC: macOS platform configuration applied")
 elseif(IOS)
     # iOS-specific configuration
-    enable_language(OBJC)
 
     # set(CMAKE_XCODE_ATTRIBUTE_ARCHS
     # set(CMAKE_XCODE_ATTRIBUTE_ENABLE_BITCODE

src/FlyView/CMakeLists.txt

@@ -14,9 +14,7 @@ qt_add_qml_module(FlyViewModule
         DefaultChecklist.qml
         FixedWingChecklist.qml
         FlightDisplayViewDummy.qml
-        FlightDisplayViewGStreamer.qml
-        FlightDisplayViewGStreamerD3D11.qml
-        FlightDisplayViewMetal.qml
+        FlightDisplayViewVideoOutput.qml
         FlightDisplayViewQtMultimedia.qml
         FlightDisplayViewUVC.qml
         FlightDisplayViewVideo.qml
@@ -65,8 +63,6 @@ qt_add_qml_module(FlyViewModule
         PreFlightSoundCheck.qml
         ProximityRadarValues.qml
         ProximityRadarVideoView.qml
-        QGCVideoBackground.qml
-        QGCVideoBackgroundD3D11.qml
         RoverChecklist.qml
         SubChecklist.qml
         TelemetryValuesBar.qml