qgstpipeline_p.h

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// Copyright (C) 2016 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
 
#ifndef qgstpipeline_p_H
#define qgstpipeline_p_H
 
//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API. It exists purely as an
// implementation detail. This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
 
#include <QtMultimedia/private/qtmultimediaglobal_p.h>
#include <QtCore/qobject.h>
 
#include "qgst_p.h"
 
QT_BEGIN_NAMESPACE
 
class QGstreamerMessage;
 
class QGstreamerSyncMessageFilter {
public:
    //returns true if message was processed and should be dropped, false otherwise
    virtual bool processSyncMessage(const QGstreamerMessage &message) = 0;
};
 
 
class QGstreamerBusMessageFilter {
public:
    //returns true if message was processed and should be dropped, false otherwise
    virtual bool processBusMessage(const QGstreamerMessage &message) = 0;
};
 
class QGstPipelinePrivate;
 
class QGstPipeline : public QGstBin
{
public:
    constexpr QGstPipeline() = default;
    QGstPipeline(const QGstPipeline &) = default;
    QGstPipeline(QGstPipeline &&) = default;
    QGstPipeline &operator=(const QGstPipeline &) = default;
    QGstPipeline &operator=(QGstPipeline &&) noexcept = default;
    QGstPipeline(GstPipeline *, RefMode mode);
    ~QGstPipeline();
 
    // installs QGstPipelinePrivate as "pipeline-private" gobject property
    static QGstPipeline create(const char *name);
    static QGstPipeline adopt(GstPipeline *);
 
    // This is needed to help us avoid sending QVideoFrames or audio buffers to the
    // application while we're prerolling the pipeline.
    // QMediaPlayer is still in a stopped state, while we put the gstreamer pipeline into a
    // Paused state so that we can get the required metadata of the stream and also have a fast
    // transition to play.
    bool inStoppedState() const;
    void setInStoppedState(bool stopped);
 
    void setFlushOnConfigChanges(bool flush);
 
    void installMessageFilter(QGstreamerSyncMessageFilter *filter);
    void removeMessageFilter(QGstreamerSyncMessageFilter *filter);
    void installMessageFilter(QGstreamerBusMessageFilter *filter);
    void removeMessageFilter(QGstreamerBusMessageFilter *filter);
 
    GstStateChangeReturn setState(GstState state);
 
    GstPipeline *pipeline() const { return GST_PIPELINE_CAST(get()); }
 
    void processMessages(GstMessageType = GST_MESSAGE_ANY);
 
    void dumpGraph(const char *fileName);
 
    template <typename Functor>
    void modifyPipelineWhileNotRunning(Functor &&fn)
    {
        beginConfig();
        fn();
        endConfig();
    }
 
    template <typename Functor>
    static void modifyPipelineWhileNotRunning(QGstPipeline &&pipeline, Functor &&fn)
    {
        if (pipeline)
            pipeline.modifyPipelineWhileNotRunning(fn);
        else
            fn();
    }
 
    void flush();
 
    bool seek(qint64 pos, double rate);
    bool setPlaybackRate(double rate, bool applyToPipeline = true);
    double playbackRate() const;
 
    bool setPosition(qint64 pos);
    qint64 position() const;
 
    qint64 duration() const;
 
private:
    QGstPipelinePrivate *getPrivate() const;
 
    void beginConfig();
    void endConfig();
};
 
QT_END_NAMESPACE
 
#endif