DirectShow: Add the zoom control

Makes is possible to to control the zoom value, if the camera supports
it.

[ChangeLog][DirectShow] Added camera zoom support.

Change-Id: I7a24c7fefb947bdcfc3ff8f755aa761135cc6fde
Reviewed-by: Andy Shaw <andy.shaw@qt.io>

5 files changed, 309 insertions, 2 deletions

diff --git a/src/plugins/directshow/camera/camera.pri b/src/plugins/directshow/camera/camera.pri
index 5d8c4cfe4..0e1c1e895 100644
--- a/src/plugins/directshow/camera/camera.pri
+++ b/src/plugins/directshow/camera/camera.pri
@@ -14,7 +14,8 @@ HEADERS += \
     $$PWD/dscameraimageprocessingcontrol.h \
     $$PWD/directshowcameraexposurecontrol.h \
     $$PWD/directshowcameracapturedestinationcontrol.h \
-    $$PWD/directshowcameracapturebufferformatcontrol.h
+    $$PWD/directshowcameracapturebufferformatcontrol.h \
+    $$PWD/directshowcamerazoomcontrol.h
 
 SOURCES += \
     $$PWD/dscameraservice.cpp \
@@ -27,7 +28,8 @@ SOURCES += \
     $$PWD/dscameraimageprocessingcontrol.cpp \
     $$PWD/directshowcameraexposurecontrol.cpp \
     $$PWD/directshowcameracapturedestinationcontrol.cpp \
-    $$PWD/directshowcameracapturebufferformatcontrol.cpp
+    $$PWD/directshowcameracapturebufferformatcontrol.cpp \
+    $$PWD/directshowcamerazoomcontrol.cpp
 
 *-msvc*:INCLUDEPATH += $$(DXSDK_DIR)/include
 QMAKE_USE += directshow
diff --git a/src/plugins/directshow/camera/directshowcamerazoomcontrol.cpp b/src/plugins/directshow/camera/directshowcamerazoomcontrol.cpp
new file mode 100644
index 000000000..209cb5d96
--- /dev/null
+++ b/src/plugins/directshow/camera/directshowcamerazoomcontrol.cpp
@@ -0,0 +1,209 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "directshowcamerazoomcontrol.h"
+#include "dscamerasession.h"
+#include "directshowutils.h"
+
+QT_BEGIN_NAMESPACE
+
+inline static qreal defaultZoomValue() { return qreal(1.0); }
+
+DirectShowCameraZoomControl::DirectShowCameraZoomControl(DSCameraSession *session)
+    : m_session(session)
+    , m_opticalZoom({0, 0, 0, 0, 0})
+    , m_currentOpticalZoom(qreal(0.0))
+    , m_requestedOpticalZoom(qreal(0.0))
+    , m_maxOpticalZoom(qreal(1.0))
+{
+    Q_ASSERT(m_session);
+    connect(m_session, &DSCameraSession::statusChanged,
+            this, &DirectShowCameraZoomControl::onStatusChanged);
+}
+
+qreal DirectShowCameraZoomControl::maximumOpticalZoom() const
+{
+    return m_maxOpticalZoom;
+}
+
+qreal DirectShowCameraZoomControl::maximumDigitalZoom() const
+{
+    return defaultZoomValue();
+}
+
+qreal DirectShowCameraZoomControl::requestedOpticalZoom() const
+{
+    return qMax(defaultZoomValue(), m_requestedOpticalZoom);
+}
+
+qreal DirectShowCameraZoomControl::requestedDigitalZoom() const
+{
+    return defaultZoomValue();
+}
+
+qreal DirectShowCameraZoomControl::currentOpticalZoom() const
+{
+    return qMax(defaultZoomValue(), m_currentOpticalZoom);
+}
+
+qreal DirectShowCameraZoomControl::currentDigitalZoom() const
+{
+    return defaultZoomValue();
+}
+
+void DirectShowCameraZoomControl::zoomTo(qreal optical, qreal digital)
+{
+    Q_UNUSED(digital);
+    if (!(m_opticalZoom.caps & CameraControl_Flags_Manual))
+        return;
+
+    if (qFuzzyCompare(optical, m_requestedOpticalZoom))
+        return;
+
+    m_requestedOpticalZoom = optical;
+    Q_EMIT requestedOpticalZoomChanged(m_requestedOpticalZoom);
+
+    if (qFuzzyCompare(m_requestedOpticalZoom, m_currentOpticalZoom))
+        return;
+
+    if (m_session->status() != QCamera::LoadedStatus && m_session->status() != QCamera::ActiveStatus)
+        return; // We'll wait until the camera is loaded, see: statusChanged connection
+
+    opticalZoomToPrivate(optical);
+}
+
+void DirectShowCameraZoomControl::onStatusChanged(QCamera::Status status)
+{
+    if (status == QCamera::LoadedStatus) {
+        updateZoomValues();
+    } else if (status == QCamera::UnloadedStatus) {
+        SecureZeroMemory(&m_opticalZoom, sizeof(ZoomValues));
+        m_currentOpticalZoom = qreal(0.0);
+        m_requestedOpticalZoom = qreal(0.0);
+    }
+
+}
+
+void DirectShowCameraZoomControl::updateZoomValues()
+{
+    IAMCameraControl *cameraControl = nullptr;
+    const DirectShowUtils::ScopedSafeRelease<IAMCameraControl> rControl { &cameraControl };
+    if (!m_session->getCameraControlInterface(&cameraControl))
+        return;
+
+    ZoomValues values { 0, 0, 0, 0, 0 };
+    // Zoom levels in DS are in the range [10, 600]
+    // The default zoom is device specific.
+    HRESULT hr = cameraControl->GetRange(CameraControl_Zoom,
+                                         &values.minZoom,
+                                         &values.maxZoom,
+                                         &values.stepping,
+                                         &values.defaultZoom,
+                                         &values.caps);
+
+    if (FAILED(hr)) {
+        qCDebug(qtDirectShowPlugin, "Getting the camera's zoom properties failed");
+        SecureZeroMemory(&m_opticalZoom, sizeof(ZoomValues));
+        return;
+    }
+
+    if (!(values.caps & CameraControl_Flags_Manual)) {
+        qCDebug(qtDirectShowPlugin, "Camera does not support manual zoom");
+        SecureZeroMemory(&m_opticalZoom, sizeof(ZoomValues));
+        return;
+    }
+
+    if (values.maxZoom != m_opticalZoom.maxZoom) {
+        const qreal newMaxZoomScale = (values.minZoom == 0) ? defaultZoomValue()
+                                                            : (qreal(values.maxZoom) / qreal(values.minZoom));
+        if (!qFuzzyCompare(newMaxZoomScale, m_maxOpticalZoom)) {
+            m_maxOpticalZoom = newMaxZoomScale;
+            Q_EMIT maximumOpticalZoomChanged(m_maxOpticalZoom);
+        }
+    }
+
+    m_opticalZoom = values;
+
+    long currentZoom = 0;
+    long flags = 0;
+    if (FAILED(cameraControl->Get(CameraControl_Zoom, &currentZoom, &flags))) {
+        qCDebug(qtDirectShowPlugin, "Getting the camera's current zoom value failed!");
+        return;
+    }
+
+    qreal currentOpticalZoom = (m_opticalZoom.minZoom == 0) ? defaultZoomValue()
+                                                            : (qreal(currentZoom) / qreal(m_opticalZoom.minZoom));
+    currentOpticalZoom = qMax(defaultZoomValue(), currentOpticalZoom);
+    if (!qFuzzyCompare(m_currentOpticalZoom, currentOpticalZoom)) {
+        m_currentOpticalZoom = currentOpticalZoom;
+        Q_EMIT currentOpticalZoomChanged(m_currentOpticalZoom);
+    }
+
+    // Check if there is a pending zoom value.
+    if (!qFuzzyCompare(m_currentOpticalZoom, m_requestedOpticalZoom))
+        opticalZoomToPrivate(m_requestedOpticalZoom);
+}
+
+bool DirectShowCameraZoomControl::opticalZoomToPrivate(qreal scaleFactor)
+{
+    IAMCameraControl *cameraControl = nullptr;
+    const DirectShowUtils::ScopedSafeRelease<IAMCameraControl> rControl { &cameraControl };
+    if (!m_session->getCameraControlInterface(&cameraControl))
+        return false;
+
+    // Convert to DS zoom value
+    const int newDSOpticalZoom = qRound(m_opticalZoom.minZoom * scaleFactor);
+    long newDSOpticalZoomAdjusted = newDSOpticalZoom - (newDSOpticalZoom % m_opticalZoom.stepping);
+    newDSOpticalZoomAdjusted = qBound(m_opticalZoom.minZoom, newDSOpticalZoomAdjusted, m_opticalZoom.maxZoom);
+
+    if (FAILED(cameraControl->Set(CameraControl_Zoom, newDSOpticalZoomAdjusted, CameraControl_Flags_Manual))) {
+        qCDebug(qtDirectShowPlugin, "Setting the camera's zoom value failed");
+        return false;
+    }
+
+    const qreal newScaleFactor = (m_opticalZoom.minZoom == 0) ? defaultZoomValue()
+                                                              : (qreal(newDSOpticalZoomAdjusted) / qreal(m_opticalZoom.minZoom));
+    // convert back to Qt scale value
+    m_currentOpticalZoom = qMax(defaultZoomValue(), newScaleFactor);
+    Q_EMIT currentOpticalZoomChanged(m_currentOpticalZoom);
+
+    return true;
+}
+
+QT_END_NAMESPACE
diff --git a/src/plugins/directshow/camera/directshowcamerazoomcontrol.h b/src/plugins/directshow/camera/directshowcamerazoomcontrol.h
new file mode 100644
index 000000000..f6fb05b0e
--- /dev/null
+++ b/src/plugins/directshow/camera/directshowcamerazoomcontrol.h
@@ -0,0 +1,88 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef DIRECTSHOWCAMERAZOOMCONTROL_H
+#define DIRECTSHOWCAMERAZOOMCONTROL_H
+
+#include <QtMultimedia/qcamerazoomcontrol.h>
+#include <QtMultimedia/qcamera.h>
+
+QT_BEGIN_NAMESPACE
+
+class DSCameraSession;
+
+class DirectShowCameraZoomControl : public QCameraZoomControl
+{
+    Q_OBJECT
+public:
+    DirectShowCameraZoomControl(DSCameraSession *session);
+
+    qreal maximumOpticalZoom() const override;
+    qreal maximumDigitalZoom() const override;
+    qreal requestedOpticalZoom() const override;
+    qreal requestedDigitalZoom() const override;
+    qreal currentOpticalZoom() const override;
+    qreal currentDigitalZoom() const override;
+    void zoomTo(qreal optical, qreal digital) override;
+
+private Q_SLOTS:
+    void onStatusChanged(QCamera::Status status);
+
+private:
+    DSCameraSession *m_session;
+    struct ZoomValues
+    {
+        long maxZoom;
+        long minZoom;
+        long stepping;
+        long defaultZoom;
+        long caps;
+    } m_opticalZoom;
+
+    qreal m_currentOpticalZoom;
+    qreal m_requestedOpticalZoom;
+    qreal m_maxOpticalZoom;
+
+    void updateZoomValues();
+    bool opticalZoomToPrivate(qreal value);
+};
+
+QT_END_NAMESPACE
+
+#endif // DIRECTSHOWCAMERAZOOMCONTROL_H
diff --git a/src/plugins/directshow/camera/dscameraservice.cpp b/src/plugins/directshow/camera/dscameraservice.cpp
index b4031c829..a806cabe3 100644
--- a/src/plugins/directshow/camera/dscameraservice.cpp
+++ b/src/plugins/directshow/camera/dscameraservice.cpp
@@ -52,6 +52,7 @@
 #include "directshowcameracapturedestinationcontrol.h"
 #include "directshowcameracapturebufferformatcontrol.h"
 #include "directshowvideoprobecontrol.h"
+#include "directshowcamerazoomcontrol.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -68,6 +69,7 @@ DSCameraService::DSCameraService(QObject *parent):
   , m_captureDestinationControl(new DirectShowCameraCaptureDestinationControl(m_session))
   , m_captureBufferFormatControl(new DirectShowCameraCaptureBufferFormatControl)
   , m_videoProbeControl(nullptr)
+  , m_zoomControl(new DirectShowCameraZoomControl(m_session))
 {
 }
 
@@ -84,6 +86,7 @@ DSCameraService::~DSCameraService()
     delete m_captureDestinationControl;
     delete m_captureBufferFormatControl;
     delete m_videoProbeControl;
+    delete m_zoomControl;
 }
 
 QMediaControl* DSCameraService::requestControl(const char *name)
@@ -128,6 +131,9 @@ QMediaControl* DSCameraService::requestControl(const char *name)
         return m_videoProbeControl;
     }
 
+    if (qstrcmp(name, QCameraZoomControl_iid) == 0)
+        return m_zoomControl;
+
     return 0;
 }
 
diff --git a/src/plugins/directshow/camera/dscameraservice.h b/src/plugins/directshow/camera/dscameraservice.h
index b437a2c10..f444eeb51 100644
--- a/src/plugins/directshow/camera/dscameraservice.h
+++ b/src/plugins/directshow/camera/dscameraservice.h
@@ -56,6 +56,7 @@ class DirectShowCameraExposureControl;
 class DirectShowCameraCaptureDestinationControl;
 class DirectShowCameraCaptureBufferFormatControl;
 class DirectShowVideoProbeControl;
+class DirectShowCameraZoomControl;
 
 class DSCameraService : public QMediaService
 {
@@ -80,6 +81,7 @@ private:
     DirectShowCameraCaptureDestinationControl *m_captureDestinationControl;
     DirectShowCameraCaptureBufferFormatControl *m_captureBufferFormatControl;
     DirectShowVideoProbeControl *m_videoProbeControl;
+    DirectShowCameraZoomControl *m_zoomControl;
 };
 
 QT_END_NAMESPACE