qwindowsmediafoundation.cpp

Go to the documentation of this file.

// Copyright (C) 2021 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qwindowsmediafoundation_p.h"
 
#include <QtCore/qdebug.h>
#include <QtCore/qmutex.h>
#include <QtCore/private/qfunctions_win_p.h>
 
QT_BEGIN_NAMESPACE
 
namespace {
 
Q_GLOBAL_STATIC(QWindowsMediaFoundation, s_wmf);
 
template <typename T>
bool setProcAddress(QSystemLibrary &lib, T &f, const char name[])
{
    f = reinterpret_cast<T>(lib.resolve(name));
    return static_cast<bool>(f);
}
 
} // namespace
 
QWindowsMediaFoundation *QWindowsMediaFoundation::instance()
{
    if (s_wmf->valid())
        return s_wmf;
 
    return nullptr;
}
 
QWindowsMediaFoundation::QWindowsMediaFoundation()
{
    if (!m_mfplat.load(false))
        return;
 
    if (!m_mf.load(false))
        return;
 
    if (!m_mfreadwrite.load(false))
        return;
 
    m_valid = setProcAddress(m_mfplat, mfStartup, "MFStartup")
            && setProcAddress(m_mfplat, mfShutdown, "MFShutdown")
            && setProcAddress(m_mfplat, mfCreateMediaType, "MFCreateMediaType")
            && setProcAddress(m_mfplat, mfCreateMemoryBuffer, "MFCreateMemoryBuffer")
            && setProcAddress(m_mfplat, mfCreateSample, "MFCreateSample")
            && setProcAddress(m_mfplat, mfCreateAttributes, "MFCreateAttributes")
            && setProcAddress(m_mf, mfEnumDeviceSources, "MFEnumDeviceSources")
            && setProcAddress(m_mfreadwrite, mfCreateSourceReaderFromMediaSource,
                              "MFCreateSourceReaderFromMediaSource");
 
    Q_ASSERT(m_valid); // If it is not valid at this point, we have a programming bug
}
 
QWindowsMediaFoundation::~QWindowsMediaFoundation() = default;
 
bool QWindowsMediaFoundation::valid() const
{
    return m_valid;
}
 
QMFRuntimeInit::QMFRuntimeInit()
    : QMFRuntimeInit{
          QWindowsMediaFoundation::instance(),
      }
{
}
 
static HRESULT startupMediaFoundation(QWindowsMediaFoundation *wmf)
{
    qt_win_ensureComInitializedOnThisThread();
    return wmf ? wmf->mfStartup(MF_VERSION, MFSTARTUP_FULL) : E_FAIL;
}
 
QMFRuntimeInit::QMFRuntimeInit(QWindowsMediaFoundation *wmf)
    : m_wmf{ wmf }, m_initResult{ startupMediaFoundation(wmf) }
{
    if (m_initResult != S_OK)
        qErrnoWarning(m_initResult, "Failed to initialize Windows Media Foundation");
}
 
QMFRuntimeInit::~QMFRuntimeInit()
{
    // According to documentation MFShutdown should be called
    // also when MFStartup failed. This is wrong.
    if (FAILED(m_initResult))
        return;
 
    const HRESULT hr = m_wmf->mfShutdown();
    if (hr != S_OK)
        qErrnoWarning(hr, "Failed to shut down Windows Media Foundation");
}
 
QT_END_NAMESPACE