Fix ffmpeg compilation and tests on win CI

- fix unused variables
- fix screen capture crash
- related commit in qt5 fixes ffmpeg build on CI

Currently, the build works with msvc and mingw,
llvm should be added in the next commits.

See build example:
https://testresults.qt.io/coin/integration/qt/qtmultimedia/tasks/web_qt_qtmultimedia_1667916985085

Pick-to: 6.4
Change-Id: Ibd27c7520a00899c893a842eef55fa4f30eba948
Reviewed-by: Lars Knoll <lars@knoll.priv.no>

3 files changed, 21 insertions, 8 deletions

diff --git a/src/plugins/multimedia/ffmpeg/qffmpeghwaccel_d3d11.cpp b/src/plugins/multimedia/ffmpeg/qffmpeghwaccel_d3d11.cpp
index f0a6c7b91..34483c9d6 100644
--- a/src/plugins/multimedia/ffmpeg/qffmpeghwaccel_d3d11.cpp
+++ b/src/plugins/multimedia/ffmpeg/qffmpeghwaccel_d3d11.cpp
@@ -31,7 +31,7 @@ public:
         : m_tex(tex)
     {}
 
-    qint64 textureHandle(int plane) override
+    qint64 textureHandle(int /*plane*/) override
     {
         return qint64(m_tex.get());
     }
@@ -122,7 +122,6 @@ TextureSet *D3D11TextureConverter::getTextures(AVFrame *frame)
         if (sharedTex) {
             auto tex = copyTextureFromArray(dev, sharedTex.get(), index);
             if (tex) {
-                QVideoFrameFormat::PixelFormat format = QFFmpegVideoBuffer::toQtPixelFormat(AVPixelFormat(fCtx->sw_format));
                 return new D3D11TextureSet(std::move(tex));
             }
         }
diff --git a/src/plugins/multimedia/ffmpeg/qffmpegscreencapture_dxgi.cpp b/src/plugins/multimedia/ffmpeg/qffmpegscreencapture_dxgi.cpp
index e9348d051..9694bf29f 100644
--- a/src/plugins/multimedia/ffmpeg/qffmpegscreencapture_dxgi.cpp
+++ b/src/plugins/multimedia/ffmpeg/qffmpegscreencapture_dxgi.cpp
@@ -166,6 +166,8 @@ public:
 
     void run() override
     {
+        // TODO: refactor with QTimer
+
         qCDebug(qLcScreenCaptureDxgi) << "ScreenGrabberActive started";
 
         DXGI_OUTDUPL_DESC outputDesc = {};
@@ -293,7 +295,10 @@ QFFmpegScreenCaptureDxgi::QFFmpegScreenCaptureDxgi(QScreenCapture *screenCapture
 {
 }
 
-QFFmpegScreenCaptureDxgi::~QFFmpegScreenCaptureDxgi() = default;
+QFFmpegScreenCaptureDxgi::~QFFmpegScreenCaptureDxgi()
+{
+    resetGrabber();
+}
 
 QVideoFrameFormat QFFmpegScreenCaptureDxgi::format() const
 {
@@ -326,11 +331,7 @@ void QFFmpegScreenCaptureDxgi::setActiveInternal(bool active)
         return;
 
     if (m_active) {
-        m_active->requestInterruption();
-        m_active->quit();
-        m_active->wait();
-        m_active.reset();
-
+        resetGrabber();
     } else {
         QScreen *screen = m_screen ? m_screen : QGuiApplication::primaryScreen();
         auto maybeDxgiScreen = findDxgiScreen(screen);
@@ -371,4 +372,14 @@ void QFFmpegScreenCaptureDxgi::setActive(bool active)
     emit screenCapture()->activeChanged(active);
 }
 
+void QFFmpegScreenCaptureDxgi::resetGrabber()
+{
+    if (m_active) {
+        m_active->requestInterruption();
+        m_active->quit();
+        m_active->wait();
+        m_active.reset();
+    }
+}
+
 QT_END_NAMESPACE
diff --git a/src/plugins/multimedia/ffmpeg/qffmpegscreencapture_dxgi_p.h b/src/plugins/multimedia/ffmpeg/qffmpegscreencapture_dxgi_p.h
index d90db328e..5c93888bd 100644
--- a/src/plugins/multimedia/ffmpeg/qffmpegscreencapture_dxgi_p.h
+++ b/src/plugins/multimedia/ffmpeg/qffmpegscreencapture_dxgi_p.h
@@ -40,6 +40,9 @@ public:
 private:
     void setActiveInternal(bool active);
 
+    void resetGrabber();
+
+private:
     std::unique_ptr<DxgiScreenGrabberActive> m_active;
     QScreen *m_screen = nullptr;
     QVideoFrameFormat m_format;