DirectShow: Add utility class

Centralized place for helper functions etc.

Change-Id: Ia4474d0681a37fc95a100a3766800141a8b1d900
Reviewed-by: Yoann Lopes <yoann.lopes@qt.io>

5 files changed, 407 insertions, 36 deletions

diff --git a/src/plugins/directshow/camera/dscamerasession.cpp b/src/plugins/directshow/camera/dscamerasession.cpp
index 83abd983e..2b0795b44 100644
--- a/src/plugins/directshow/camera/dscamerasession.cpp
+++ b/src/plugins/directshow/camera/dscamerasession.cpp
@@ -49,11 +49,10 @@
 #include "dsvideorenderer.h"
 #include "directshowcameraglobal.h"
 #include "directshowmediatype.h"
+#include "directshowutils.h"
 
 QT_BEGIN_NAMESPACE
 
-static HRESULT getPin(IBaseFilter *filter, PIN_DIRECTION pinDir, IPin **pin);
-
 class SampleGrabberCallbackPrivate : public ISampleGrabberCB
 {
 public:
@@ -1036,8 +1035,7 @@ void DSCameraSession::updateSourceCapabilities()
         qWarning() << "Failed to get the video control";
     } else {
         IPin *pPin = 0;
-        hr = getPin(m_sourceFilter, PINDIR_OUTPUT, &pPin);
-        if (FAILED(hr)) {
+        if (!DirectShowUtils::getPin(m_sourceFilter, PINDIR_OUTPUT, &pPin, &hr)) {
             qWarning() << "Failed to get the pin for the video control";
         } else {
             long supportedModes;
@@ -1089,8 +1087,7 @@ void DSCameraSession::updateSourceCapabilities()
 
                 if (pVideoControl) {
                     IPin *pPin = 0;
-                    hr = getPin(m_sourceFilter, PINDIR_OUTPUT, &pPin);
-                    if (FAILED(hr)) {
+                    if (!DirectShowUtils::getPin(m_sourceFilter, PINDIR_OUTPUT, &pPin, &hr)) {
                         qWarning() << "Failed to get the pin for the video control";
                     } else {
                         long listSize = 0;
@@ -1137,30 +1134,4 @@ void DSCameraSession::updateSourceCapabilities()
     updateImageProcessingParametersInfos();
 }
 
-HRESULT getPin(IBaseFilter *pFilter, PIN_DIRECTION PinDir, IPin **ppPin)
-{
-    *ppPin = 0;
-    IEnumPins *pEnum = 0;
-    IPin *pPin = 0;
-
-    HRESULT hr = pFilter->EnumPins(&pEnum);
-    if (FAILED(hr)) {
-        return hr;
-    }
-
-    pEnum->Reset();
-    while (pEnum->Next(1, &pPin, NULL) == S_OK) {
-        PIN_DIRECTION ThisPinDir;
-        pPin->QueryDirection(&ThisPinDir);
-        if (ThisPinDir == PinDir) {
-            pEnum->Release();
-            *ppPin = pPin;
-            return S_OK;
-        }
-        pPin->Release();
-    }
-    pEnum->Release();
-    return E_FAIL;
-}
-
 QT_END_NAMESPACE
diff --git a/src/plugins/directshow/dsserviceplugin.cpp b/src/plugins/directshow/dsserviceplugin.cpp
index 1c9d0eee1..4b84841bd 100644
--- a/src/plugins/directshow/dsserviceplugin.cpp
+++ b/src/plugins/directshow/dsserviceplugin.cpp
@@ -78,9 +78,11 @@ extern const CLSID CLSID_VideoInputDeviceCategory;
 #include <ocidl.h>
 #endif
 
-QT_USE_NAMESPACE
-
+QT_BEGIN_NAMESPACE
 Q_LOGGING_CATEGORY(qtDirectShowPlugin, "qt.multimedia.plugins.directshow")
+QT_END_NAMESPACE
+
+QT_USE_NAMESPACE
 
 static int g_refCount = 0;
 void addRefCount()
diff --git a/src/plugins/directshow/helpers/directshowutils.cpp b/src/plugins/directshow/helpers/directshowutils.cpp
new file mode 100644
index 000000000..d9701fd99
--- /dev/null
+++ b/src/plugins/directshow/helpers/directshowutils.cpp
@@ -0,0 +1,309 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 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 "directshowutils.h"
+
+/**
+ * @brief DirectShowUtils::isPinConnected
+ * @param pin
+ * @param hrOut
+ * @return
+ */
+bool DirectShowUtils::isPinConnected(IPin *pin, HRESULT *hrOut)
+{
+    IPin *connectedPin = nullptr;
+    const ScopedSafeRelease<IPin> releasePin { &connectedPin };
+    HRESULT hr = S_OK;
+    if (!hrOut)
+        hrOut = &hr;
+
+    *hrOut = pin->ConnectedTo(&connectedPin);
+    if (*hrOut == VFW_E_NOT_CONNECTED) // Not an error in this case
+        *hrOut = S_OK;
+
+    if (FAILED(*hrOut)) {
+        qCDebug(qtDirectShowPlugin, "Querying pin connection failed!");
+        return false;
+    }
+
+    return true;
+}
+
+/**
+ * @brief DirectShowUtils::hasPinDirection
+ * @param pin
+ * @param direction
+ * @param hrOut
+ * @return
+ */
+bool DirectShowUtils::hasPinDirection(IPin *pin, PIN_DIRECTION direction, HRESULT *hrOut)
+{
+    PIN_DIRECTION pinDir;
+    HRESULT hr = S_OK;
+    if (!hrOut)
+        hrOut = &hr;
+
+    *hrOut = pin->QueryDirection(&pinDir);
+
+    if (FAILED(*hrOut)) {
+        qCDebug(qtDirectShowPlugin, "Querying pin direction failed!");
+        return false;
+    }
+
+    return (pinDir == direction);
+}
+
+/**
+ * @brief DirectShowUtils::getPin
+ * @param filter
+ * @param pinDirection
+ * @param pin
+ * @param hrOut
+ * @return
+ */
+bool DirectShowUtils::getPin(IBaseFilter *filter, PIN_DIRECTION pinDirection, IPin **pin, HRESULT *hrOut)
+{
+    IEnumPins *enumPins = nullptr;
+    const ScopedSafeRelease<IEnumPins> releaseEnumPins { &enumPins };
+    HRESULT hr S_OK;
+    if (!hrOut)
+        hrOut = &hr;
+
+    *hrOut = filter->EnumPins(&enumPins);
+    if (FAILED(*hrOut)) {
+        qCDebug(qtDirectShowPlugin, "Unable to retrieve pins from the filter!");
+        return false;
+    }
+
+    enumPins->Reset();
+    IPin *nextPin = nullptr;
+    while (enumPins->Next(1, &nextPin, NULL) == S_OK) {
+        const ScopedSafeRelease<IPin> releasePin { &nextPin };
+        PIN_DIRECTION currentPinDir;
+        *hrOut = nextPin->QueryDirection(&currentPinDir);
+        if (currentPinDir == pinDirection) {
+            *pin = nextPin;
+            (*pin)->AddRef();
+            return true;
+        }
+    }
+
+    return false;
+}
+
+/**
+ * @brief DirectShowUtils::matchPin
+ * @param pin
+ * @param pinDirection
+ * @param shouldBeConnected
+ * @param hrOut
+ * @return
+ */
+bool DirectShowUtils::matchPin(IPin *pin, PIN_DIRECTION pinDirection, BOOL shouldBeConnected, HRESULT *hrOut)
+{
+    HRESULT hr = S_OK;
+    if (!hrOut)
+        hrOut = &hr;
+
+    const BOOL isConnected = isPinConnected(pin, hrOut);
+    if (FAILED(*hrOut)) // Error reason will already be logged, so just return.
+        return false;
+
+    if (isConnected == shouldBeConnected)
+        return hasPinDirection(pin, pinDirection, hrOut);
+
+    return SUCCEEDED(*hrOut);
+}
+
+/**
+ * @brief DirectShowUtils::findUnconnectedPin
+ * @param filter
+ * @param pinDirection
+ * @param pin
+ * @param hrOut
+ * @return
+ */
+bool DirectShowUtils::findUnconnectedPin(IBaseFilter *filter, PIN_DIRECTION pinDirection, IPin **pin, HRESULT *hrOut)
+{
+    HRESULT hr = S_OK;
+    if (!hrOut)
+        hrOut = &hr;
+
+    IEnumPins *enumPins = nullptr;
+    const ScopedSafeRelease<IEnumPins> releaseEnumPins { &enumPins };
+    *hrOut = filter->EnumPins(&enumPins);
+    if (FAILED(*hrOut)) {
+        qCDebug(qtDirectShowPlugin, "Unable to retrieve pins from the DS filter");
+        return false;
+    }
+
+    IPin *nextPin = nullptr;
+    while (S_OK == enumPins->Next(1, &nextPin, nullptr)) {
+        const ScopedSafeRelease<IPin> releaseNextPin { &nextPin };
+        if (matchPin(nextPin, pinDirection, FALSE, hrOut)) {
+            *pin = nextPin;
+            (*pin)->AddRef();
+            return true;
+        }
+
+        if (FAILED(*hrOut))
+            return false;
+    }
+
+    qCDebug(qtDirectShowPlugin, "No unconnected pins found");
+    *hrOut = VFW_E_NOT_FOUND;
+
+    return false;
+}
+
+/**
+ * @brief DirectShowUtils::connectFilters - Attempts to connect \a outputPin to \a filter
+ * @param graph
+ * @param outputPin
+ * @param filter
+ * @param hrOut
+ * @return
+ */
+bool DirectShowUtils::connectFilters(IGraphBuilder *graph, IPin *outputPin, IBaseFilter *filter, HRESULT *hrOut)
+{
+
+    // Find an input pin on the downstream filter.
+    HRESULT hr = S_OK;
+    if (!hrOut)
+        hrOut = &hr;
+
+    IPin *inputPin = nullptr;
+    const ScopedSafeRelease<IPin> releaseInputPin { &inputPin };
+    if (!findUnconnectedPin(filter, PINDIR_INPUT, &inputPin, hrOut))
+        return false;
+
+
+    // Try to connect them.
+    *hrOut = graph->Connect(outputPin, inputPin);
+    if (FAILED(*hrOut)) {
+        qCDebug(qtDirectShowPlugin, "Unable to connect output pin to filter!");
+        return false;
+    }
+
+    return true;
+}
+
+/**
+ * @brief DirectShowUtils::connectFilters - Attempts to connect \a filter to \a inputPin.
+ * @param graph
+ * @param filter
+ * @param inputPin
+ * @param hrOut
+ * @return
+ */
+bool DirectShowUtils::connectFilters(IGraphBuilder *graph, IBaseFilter *filter, IPin *inputPin, HRESULT *hrOut)
+{
+    HRESULT hr = S_OK;
+    if (!hrOut)
+        hrOut = &hr;
+
+    IPin *outputPin = nullptr;
+    const ScopedSafeRelease<IPin> releaseOutputPin { &outputPin };
+    // Find an output pin on the upstream filter.
+    if (findUnconnectedPin(filter, PINDIR_OUTPUT, &outputPin, hrOut))
+        return false;
+
+    *hrOut = graph->Connect(outputPin, inputPin);
+    if (FAILED(*hrOut)) {
+        qCDebug(qtDirectShowPlugin, "Unable to connect filter to input pin!");
+        return false;
+    }
+
+    return true;
+}
+
+/**
+ * @brief DirectShowUtils::connectFilters - Attempts to connect the \a upstreamFilter to \a downstreamFilter.
+ * @param graph
+ * @param upstreamFilter
+ * @param downstreamFilter
+ * @param autoConnect - If set to true all filters in the graph will be considered.
+ * @param hrOut
+ * @return true if the the filters were connected, false otherwise.
+ */
+bool DirectShowUtils::connectFilters(IGraphBuilder *graph,
+                                     IBaseFilter *upstreamFilter,
+                                     IBaseFilter *downstreamFilter,
+                                     bool autoConnect,
+                                     HRESULT *hrOut)
+{
+    HRESULT hr = S_OK;
+    if (!hrOut)
+        hrOut = &hr;
+
+    const auto findAndConnect = [graph, downstreamFilter, hrOut](IBaseFilter *filter) -> bool {
+        IPin *outputPin = nullptr;
+        const ScopedSafeRelease<IPin> releaseOutputPin { &outputPin };
+        if (findUnconnectedPin(filter, PINDIR_OUTPUT, &outputPin, hrOut))
+            return connectFilters(graph, outputPin, downstreamFilter, hrOut);
+
+        return false;
+    };
+
+    // Try to connect to the upstream filter first.
+    if (findAndConnect(upstreamFilter))
+        return S_OK;
+
+    const auto getFilters = [graph, hrOut]() -> IEnumFilters * {
+        IEnumFilters *f = nullptr;
+        *hrOut = graph->EnumFilters(&f);
+        return f;
+    };
+    IEnumFilters *filters = autoConnect ? getFilters()
+                                        : nullptr;
+    const ScopedSafeRelease<IEnumFilters> releaseEnumFilters { &filters };
+    if (!filters) {
+        qCDebug(qtDirectShowPlugin, "No filters found!");
+        return false;
+    }
+
+    IBaseFilter *nextFilter = nullptr;
+    while (S_OK == filters->Next(1, &nextFilter, 0)) {
+        const ScopedSafeRelease<IBaseFilter> releaseNextFilter { &nextFilter };
+        if (nextFilter && findAndConnect(nextFilter))
+            break;
+    }
+
+    return SUCCEEDED(*hrOut);
+}
diff --git a/src/plugins/directshow/helpers/directshowutils.h b/src/plugins/directshow/helpers/directshowutils.h
new file mode 100644
index 000000000..09c81c257
--- /dev/null
+++ b/src/plugins/directshow/helpers/directshowutils.h
@@ -0,0 +1,87 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 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 DIRECTSHOWUTILS_H
+#define DIRECTSHOWUTILS_H
+
+#include "directshowglobal.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace DirectShowUtils
+{
+template <typename T>
+void safeRelease(T **iface) {
+    if (!iface)
+        return;
+
+    if (!*iface)
+        return;
+
+    (*iface)->Release();
+    *iface = nullptr;
+}
+
+template <typename T>
+struct ScopedSafeRelease
+{
+    T **iunknown;
+    ~ScopedSafeRelease()
+    {
+        DirectShowUtils::safeRelease(iunknown);
+    }
+};
+
+bool getPin(IBaseFilter *filter, PIN_DIRECTION pinDirection, IPin **pin, HRESULT *hrOut);
+bool isPinConnected(IPin *pin, HRESULT *hrOut = nullptr);
+bool hasPinDirection(IPin *pin, PIN_DIRECTION direction, HRESULT *hrOut = nullptr);
+bool matchPin(IPin *pin, PIN_DIRECTION pinDirection, BOOL shouldBeConnected, HRESULT *hrOut = nullptr);
+bool findUnconnectedPin(IBaseFilter *filter, PIN_DIRECTION pinDirection, IPin **pin, HRESULT *hrOut = nullptr);
+bool connectFilters(IGraphBuilder *graph, IPin *outputPin, IBaseFilter *filter, HRESULT *hrOut = nullptr);
+bool connectFilters(IGraphBuilder *graph, IBaseFilter *filter, IPin *inputPin, HRESULT *hrOut = nullptr);
+bool connectFilters(IGraphBuilder *graph,
+                    IBaseFilter *upstreamFilter,
+                    IBaseFilter *downstreamFilter,
+                    bool autoConnect = false,
+                    HRESULT *hrOut = nullptr);
+}
+
+QT_END_NAMESPACE
+
+#endif // DIRECTSHOWUTILS_H
diff --git a/src/plugins/directshow/helpers/helpers.pri b/src/plugins/directshow/helpers/helpers.pri
index b3743a680..ca883eeb8 100644
--- a/src/plugins/directshow/helpers/helpers.pri
+++ b/src/plugins/directshow/helpers/helpers.pri
@@ -9,7 +9,8 @@ HEADERS += \
     $$PWD/directshowobject.h \
     $$PWD/directshowpin.h \
     $$PWD/directshowpinenum.h \
-    $$PWD/directshowvideobuffer.h
+    $$PWD/directshowvideobuffer.h \
+    $$PWD/directshowutils.h
 
 SOURCES += \
     $$PWD/directshowbasefilter.cpp \
@@ -19,4 +20,5 @@ SOURCES += \
     $$PWD/directshowobject.cpp \
     $$PWD/directshowpin.cpp \
     $$PWD/directshowpinenum.cpp \
-    $$PWD/directshowvideobuffer.cpp
+    $$PWD/directshowvideobuffer.cpp \
+    $$PWD/directshowutils.cpp