Introduce a new environment variable to disable EVR in DirectShow

A new environment variable QT_DIRECTSHOW_NO_EVR is introduced to
disable EVR, which is needed in some cases (see QTBUG-53019).

Task-number: QTBUG-53019
Change-Id: I8e39ad36d37f5e7c2da0d1fdc62dc95dda715ec0
Reviewed-by: VaL Doroshchuk <valentyn.doroshchuk@qt.io>

2 files changed, 16 insertions, 12 deletions

diff --git a/src/plugins/directshow/player/directshowplayerservice.cpp b/src/plugins/directshow/player/directshowplayerservice.cpp
index 0cad3cc2e..63635b059 100644
--- a/src/plugins/directshow/player/directshowplayerservice.cpp
+++ b/src/plugins/directshow/player/directshowplayerservice.cpp
@@ -219,11 +219,13 @@ QMediaControl *DirectShowPlayerService::requestControl(const char *name)
             IBaseFilter *filter;
 
 #if QT_CONFIG(evr)
-            DirectShowEvrVideoWindowControl *evrControl = new DirectShowEvrVideoWindowControl;
-            if ((filter = evrControl->filter()))
-                m_videoWindowControl = evrControl;
-            else
-                delete evrControl;
+            if (!qgetenv("QT_DIRECTSHOW_NO_EVR").toInt()) {
+                DirectShowEvrVideoWindowControl *evrControl = new DirectShowEvrVideoWindowControl;
+                if ((filter = evrControl->filter()))
+                    m_videoWindowControl = evrControl;
+                else
+                    delete evrControl;
+            }
 #endif
             // Fall back to the VMR9 if the EVR is not available
             if (!m_videoWindowControl) {
diff --git a/src/plugins/directshow/player/directshowvideorenderercontrol.cpp b/src/plugins/directshow/player/directshowvideorenderercontrol.cpp
index ee7f5ec9e..88b5a51eb 100644
--- a/src/plugins/directshow/player/directshowvideorenderercontrol.cpp
+++ b/src/plugins/directshow/player/directshowvideorenderercontrol.cpp
@@ -98,13 +98,15 @@ void DirectShowVideoRendererControl::setSurface(QAbstractVideoSurface *surface)
 
     if (m_surface) {
 #if QT_CONFIG(evr)
-        m_filter = com_new<IBaseFilter>(clsid_EnhancedVideoRenderer);
-        m_evrPresenter = new EVRCustomPresenter(m_surface);
-        if (!m_evrPresenter->isValid() || !qt_evr_setCustomPresenter(m_filter, m_evrPresenter)) {
-            m_filter->Release();
-            m_filter = 0;
-            m_evrPresenter->Release();
-            m_evrPresenter = 0;
+        if (!qgetenv("QT_DIRECTSHOW_NO_EVR").toInt()) {
+            m_filter = com_new<IBaseFilter>(clsid_EnhancedVideoRenderer);
+            m_evrPresenter = new EVRCustomPresenter(m_surface);
+            if (!m_evrPresenter->isValid() || !qt_evr_setCustomPresenter(m_filter, m_evrPresenter)) {
+                m_filter->Release();
+                m_filter = 0;
+                m_evrPresenter->Release();
+                m_evrPresenter = 0;
+            }
         }
 
         if (!m_filter)