DirectShow: Refactor camera backend.

Almost entire rewrite of the camera backend. It doesn't provide new
features but is more stable and behave as it should.

- Correctly report camera state and status
- Correctly report if the camera is ready to capture
- Emit imageExposed() signal
- Save captured images in an appropriate directory
- Images can be captured even without a viewport
- Better error handling

Removed the custom QVideoWidgetControl as it doesn't provide anything more
than the QVideoWidget's renderer control fallback.

Task-number: QTBUG-33782
Change-Id: I9baf6f83e7c69619f20a101921f7865a1c90d5e4
Reviewed-by: Christian Stromme <christian.stromme@digia.com>

1 files changed, 24 insertions, 2 deletions

diff --git a/src/plugins/directshow/dsserviceplugin.cpp b/src/plugins/directshow/dsserviceplugin.cpp
index d262febdd..954fab22c 100644
--- a/src/plugins/directshow/dsserviceplugin.cpp
+++ b/src/plugins/directshow/dsserviceplugin.cpp
@@ -79,15 +79,32 @@ extern const CLSID CLSID_VideoInputDeviceCategory;
 
 QT_USE_NAMESPACE
 
+static int g_refCount = 0;
+void addRefCount()
+{
+    if (++g_refCount == 1)
+        CoInitialize(NULL);
+}
+
+void releaseRefCount()
+{
+    if (--g_refCount == 0)
+        CoUninitialize();
+}
+
 QMediaService* DSServicePlugin::create(QString const& key)
 {
 #ifdef QMEDIA_DIRECTSHOW_CAMERA
-    if (key == QLatin1String(Q_MEDIASERVICE_CAMERA))
+    if (key == QLatin1String(Q_MEDIASERVICE_CAMERA)) {
+        addRefCount();
         return new DSCameraService;
+    }
 #endif
 #ifdef QMEDIA_DIRECTSHOW_PLAYER
-    if (key == QLatin1String(Q_MEDIASERVICE_MEDIAPLAYER))
+    if (key == QLatin1String(Q_MEDIASERVICE_MEDIAPLAYER)) {
+        addRefCount();
         return new DirectShowPlayerService;
+    }
 #endif
 
     return 0;
@@ -96,6 +113,7 @@ QMediaService* DSServicePlugin::create(QString const& key)
 void DSServicePlugin::release(QMediaService *service)
 {
     delete service;
+    releaseRefCount();
 }
 
 QMediaServiceProviderHint::Features DSServicePlugin::supportedFeatures(
@@ -154,6 +172,8 @@ QString DSServicePlugin::deviceDescription(const QByteArray &service, const QByt
 
 void DSServicePlugin::updateDevices() const
 {
+    addRefCount();
+
     m_defaultCameraDevice.clear();
     DSVideoDeviceControl::enumerateDevices(&m_cameraDevices, &m_cameraDescriptions);
 
@@ -162,6 +182,8 @@ void DSServicePlugin::updateDevices() const
     } else {
         m_defaultCameraDevice = m_cameraDevices.first();
     }
+
+    releaseRefCount();
 }
 #endif