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Diffstat (limited to 'src/multimedia/video/qvideoprobe.cpp')
-rw-r--r-- | src/multimedia/video/qvideoprobe.cpp | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/src/multimedia/video/qvideoprobe.cpp b/src/multimedia/video/qvideoprobe.cpp new file mode 100644 index 000000000..d9d0d6587 --- /dev/null +++ b/src/multimedia/video/qvideoprobe.cpp @@ -0,0 +1,193 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** GNU Lesser General Public License Usage +** This file may be used under the terms of the GNU Lesser General Public +** License version 2.1 as published by the Free Software Foundation and +** appearing in the file LICENSE.LGPL included in the packaging of this +** file. Please review the following information to ensure the GNU Lesser +** General Public License version 2.1 requirements will be met: +** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU General +** Public License version 3.0 as published by the Free Software Foundation +** and appearing in the file LICENSE.GPL included in the packaging of this +** file. Please review the following information to ensure the GNU General +** Public License version 3.0 requirements will be met: +** http://www.gnu.org/copyleft/gpl.html. +** +** Other Usage +** Alternatively, this file may be used in accordance with the terms and +** conditions contained in a signed written agreement between you and Nokia. +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + + +/*! + \class QVideoProbe + \inmodule QtMultimedia + + \ingroup multimedia + \ingroup multimedia_video + + \brief The QVideoProbe class allows you to monitor video frames being played or recorded. + + \code + QMediaPlayer *player = new QMediaPlayer(); + QVideoProbe *probe = new QVideoProbe; + + connect(probe, SIGNAL(videoFrameProbed(QVideoFrame)), this, SLOT(processFrame(QVideoFrame))); + + probe->setSource(player); // Returns true, hopefully. + + player->setVideoOutput(myVideoSurface); + player->setMedia(QUrl::fromLocalFile("observation.mp4")); + player->play(); // Start receving frames as they get presented to myVideoSurface + \endcode + + This same approach works with the QCamera object as well, to receive viewfinder or video + frames as they are captured. + + \sa QAudioProbe, QMediaPlayer, QCamera +*/ + +#include "qvideoprobe.h" +#include "qmediavideoprobecontrol.h" +#include "qmediaservice.h" +#include "qmediarecorder.h" +#include "qsharedpointer.h" + +QT_BEGIN_NAMESPACE + +class QVideoProbePrivate { +public: + QWeakPointer<QMediaObject> source; + QWeakPointer<QMediaVideoProbeControl> probee; +}; + +/*! + Creates a new QVideoProbe class. After setting the + source to monitor with \l setSource(), the \l videoFrameProbed() + signal will be emitted when video frames are flowing in the + source media object. + */ +QVideoProbe::QVideoProbe(QObject *parent) + : QObject(parent) + , d(new QVideoProbePrivate) +{ + +} + +/*! + Destroys this probe and disconnects from any + media object. + */ +QVideoProbe::~QVideoProbe() +{ + if (d->source) { + // Disconnect + if (d->probee) + disconnect(d->probee.data(), SIGNAL(videoFrameProbed(QVideoFrame)), this, SIGNAL(videoFrameProbed(QVideoFrame))); + d->source.data()->service()->releaseControl(d->probee.data()); + } +} + +/*! + Sets the media object to monitor to \a source. + + If \a source is zero, this probe will be deactivated + and this function wil return true. + + If the media object does not support monitoring + video, this function will return false. + + Any previously monitored objects will no longer be monitored. + Passing in the same object will be ignored, but + monitoring will continue. + */ +bool QVideoProbe::setSource(QMediaObject *source) +{ + // Need to: + // 1) disconnect from current source if necessary + // 2) see if new one has the probe control + // 3) connect if so + if (source != d->source.data()) { + if (d->source) { + Q_ASSERT(d->probee); + disconnect(d->probee.data(), SIGNAL(videoFrameProbed(QVideoFrame)), this, SIGNAL(videoFrameProbed(QVideoFrame))); + d->source.data()->service()->releaseControl(d->probee.data()); + d->source.clear(); + d->probee.clear(); + } + + if (source) { + QMediaService *service = source->service(); + if (service) { + d->probee = service->requestControl<QMediaVideoProbeControl*>(); + } + + if (d->probee) { + connect(d->probee.data(), SIGNAL(videoFrameProbed(QVideoFrame)), this, SIGNAL(videoFrameProbed(QVideoFrame))); + d->source = source; + } + } + } + + return (!source || d->probee != 0); +} + +/*! + Starts monitoring the given \a mediaRecorder. + + If \a source is zero, this probe will be deactivated + and this function wil return true. + + If the media recorder instance does not support monitoring + video, this function will return false. + + Any previously monitored objects will no longer be monitored. + Passing in the same object will be ignored, but + monitoring will continue. + */ +bool QVideoProbe::setSource(QMediaRecorder *mediaRecorder) +{ + QMediaObject *source = mediaRecorder ? mediaRecorder->mediaObject() : 0; + bool result = setSource(source); + + if (!mediaRecorder) + return true; + + if (mediaRecorder && !source) + return false; + + return result; +} + +/*! + Returns true if this probe is monitoring something, or false otherwise. + + The source being monitored does not need to be active. + */ +bool QVideoProbe::isActive() const +{ + return d->probee != 0; +} + +QT_END_NAMESPACE |