DirectShow: Add video probe support for the camera

This change makes it possible to use the QVideoProbe class
with the camera.

[ChangeLog][DirectShow] Added support for video probes in the camera.

Change-Id: Ib353e80e68ea2dcc5b33fd81863f4b6613257e45
Reviewed-by: Andy Shaw <andy.shaw@qt.io>

4 files changed, 52 insertions, 0 deletions

diff --git a/src/plugins/directshow/camera/dscameraservice.cpp b/src/plugins/directshow/camera/dscameraservice.cpp
index 71c0f685a..b4031c829 100644
--- a/src/plugins/directshow/camera/dscameraservice.cpp
+++ b/src/plugins/directshow/camera/dscameraservice.cpp
@@ -51,6 +51,7 @@
 #include "directshowcameraexposurecontrol.h"
 #include "directshowcameracapturedestinationcontrol.h"
 #include "directshowcameracapturebufferformatcontrol.h"
+#include "directshowvideoprobecontrol.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -66,6 +67,7 @@ DSCameraService::DSCameraService(QObject *parent):
   , m_exposureControl(new DirectShowCameraExposureControl(m_session))
   , m_captureDestinationControl(new DirectShowCameraCaptureDestinationControl(m_session))
   , m_captureBufferFormatControl(new DirectShowCameraCaptureBufferFormatControl)
+  , m_videoProbeControl(nullptr)
 {
 }
 
@@ -81,6 +83,7 @@ DSCameraService::~DSCameraService()
     delete m_exposureControl;
     delete m_captureDestinationControl;
     delete m_captureBufferFormatControl;
+    delete m_videoProbeControl;
 }
 
 QMediaControl* DSCameraService::requestControl(const char *name)
@@ -116,6 +119,15 @@ QMediaControl* DSCameraService::requestControl(const char *name)
     if (qstrcmp(name, QCameraCaptureBufferFormatControl_iid) == 0)
         return m_captureBufferFormatControl;
 
+    if (qstrcmp(name, QMediaVideoProbeControl_iid) == 0) {
+        if (!m_videoProbeControl)
+            m_videoProbeControl = new DirectShowVideoProbeControl;
+
+        m_videoProbeControl->ref();
+        m_session->addVideoProbe(m_videoProbeControl);
+        return m_videoProbeControl;
+    }
+
     return 0;
 }
 
@@ -126,6 +138,14 @@ void DSCameraService::releaseControl(QMediaControl *control)
         m_videoRenderer = 0;
         return;
     }
+
+    if (control == m_videoProbeControl) {
+        m_session->removeVideoProbe(m_videoProbeControl);
+        if (!m_videoProbeControl->deref()) {
+            delete m_videoProbeControl;
+            m_videoProbeControl = nullptr;
+        }
+    }
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/directshow/camera/dscameraservice.h b/src/plugins/directshow/camera/dscameraservice.h
index bf2e31435..b437a2c10 100644
--- a/src/plugins/directshow/camera/dscameraservice.h
+++ b/src/plugins/directshow/camera/dscameraservice.h
@@ -55,6 +55,7 @@ class DSCameraImageProcessingControl;
 class DirectShowCameraExposureControl;
 class DirectShowCameraCaptureDestinationControl;
 class DirectShowCameraCaptureBufferFormatControl;
+class DirectShowVideoProbeControl;
 
 class DSCameraService : public QMediaService
 {
@@ -78,6 +79,7 @@ private:
     DirectShowCameraExposureControl *m_exposureControl;
     DirectShowCameraCaptureDestinationControl *m_captureDestinationControl;
     DirectShowCameraCaptureBufferFormatControl *m_captureBufferFormatControl;
+    DirectShowVideoProbeControl *m_videoProbeControl;
 };
 
 QT_END_NAMESPACE
diff --git a/src/plugins/directshow/camera/dscamerasession.cpp b/src/plugins/directshow/camera/dscamerasession.cpp
index 82125d4f6..9b642872a 100644
--- a/src/plugins/directshow/camera/dscamerasession.cpp
+++ b/src/plugins/directshow/camera/dscamerasession.cpp
@@ -51,6 +51,7 @@
 #include "directshowcameraglobal.h"
 #include "directshowmediatype.h"
 #include "directshowutils.h"
+#include "directshowvideoprobecontrol.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -70,6 +71,7 @@ DSCameraSession::DSCameraSession(QObject *parent)
     , m_imageIdCounter(0)
     , m_currentImageId(-1)
     , m_captureDestinations(QCameraImageCapture::CaptureToFile)
+    , m_videoProbeControl(nullptr)
     , m_status(QCamera::UnloadedStatus)
 {
     connect(this, SIGNAL(statusChanged(QCamera::Status)),
@@ -374,6 +376,20 @@ void DSCameraSession::setCaptureDestination(QCameraImageCapture::CaptureDestinat
     Q_EMIT captureDestinationChanged(m_captureDestinations);
 }
 
+void DSCameraSession::addVideoProbe(DirectShowVideoProbeControl *probe)
+{
+    const QMutexLocker locker(&m_probeMutex);
+    m_videoProbeControl = probe;
+}
+
+void DSCameraSession::removeVideoProbe(DirectShowVideoProbeControl *probe)
+{
+    Q_UNUSED(probe);
+    Q_ASSERT(m_videoProbeControl == probe);
+    const QMutexLocker locker(&m_probeMutex);
+    m_videoProbeControl = nullptr;
+}
+
 bool DSCameraSession::load()
 {
     unload();
@@ -567,6 +583,12 @@ void DSCameraSession::onFrameAvailable(double time, const QByteArray &data)
 
     m_presentMutex.unlock();
 
+    {
+        const QMutexLocker locker(&m_probeMutex);
+        if (m_currentFrame.isValid() && m_videoProbeControl)
+            Q_EMIT m_videoProbeControl->videoFrameProbed(m_currentFrame);
+    }
+
     // Image capture
     QMutexLocker locker(&m_captureMutex);
     if (m_currentImageId != -1 && !m_capturedFrame.isValid()) {
diff --git a/src/plugins/directshow/camera/dscamerasession.h b/src/plugins/directshow/camera/dscamerasession.h
index 85bddbc9e..e28015534 100644
--- a/src/plugins/directshow/camera/dscamerasession.h
+++ b/src/plugins/directshow/camera/dscamerasession.h
@@ -77,6 +77,7 @@ struct ICaptureGraphBuilder2;
 QT_BEGIN_NAMESPACE
 
 class DirectShowSampleGrabber;
+class DirectShowVideoProbeControl;
 
 class DSCameraSession : public QObject
 {
@@ -125,6 +126,9 @@ public:
     QCameraImageCapture::CaptureDestinations captureDestination() const;
     void setCaptureDestination(QCameraImageCapture::CaptureDestinations destinations);
 
+    void addVideoProbe(DirectShowVideoProbeControl *probe);
+    void removeVideoProbe(DirectShowVideoProbeControl *probe);
+
 Q_SIGNALS:
     void statusChanged(QCamera::Status);
     void imageExposed(int id);
@@ -217,6 +221,10 @@ private:
     QVideoFrame m_capturedFrame;
     QCameraImageCapture::CaptureDestinations m_captureDestinations;
 
+    // Video probe
+    QMutex m_probeMutex;
+    DirectShowVideoProbeControl *m_videoProbeControl;
+
     // Internal state
     QCamera::Status m_status;