qffmpegrecordingengineutils_p.h

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// Copyright (C) 2024 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 QFFMPEGRECORDINGENGINEUTILS_P_H
#define QFFMPEGRECORDINGENGINEUTILS_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 "qobject.h"
#include <QtMultimedia/qvideoframe.h>
#include <optional>
#include <queue>
 
QT_BEGIN_NAMESPACE
 
class QMediaInputEncoderInterface;
class QPlatformVideoSource;
 
namespace QFFmpeg {
 
constexpr qint64 VideoFrameTimeBase = 1000000; // us in sec
 
// Fallback frame rate used when no real rate is known (e.g. variable-rate sources
// with untimed frames), chosen to keep pts advancing and satisfy players/muxers
// that require a valid duration.
constexpr int DefaultVideoFrameRate = 30;
 
class EncoderThread;
 
struct FrameInfo
{
    QVideoFrame frame;
    bool adjustTimeBase{ false };
    std::optional<qint64> overriddenPts;
};
 
template <typename T>
T dequeueIfPossible(std::queue<T> &queue)
{
    if (queue.empty())
        return T{};
 
    auto result = std::move(queue.front());
    queue.pop();
    return result;
}
 
void setEncoderInterface(QObject *source, QMediaInputEncoderInterface *);
 
void setEncoderUpdateConnection(QObject *source, EncoderThread *encoder);
 
template <typename Encoder, typename Source>
void connectEncoderToSource(Encoder *encoder, Source *source)
{
    Q_ASSERT(!encoder->source());
    encoder->setSource(source);
 
    if constexpr (std::is_same_v<Source, QPlatformVideoSource>) {
        QObject::connect(source, &Source::newVideoFrame, encoder, &Encoder::addFrame,
                         Qt::DirectConnection);
 
        QObject::connect(source, &Source::activeChanged, encoder, [=]() {
            if (!source->isActive())
                encoder->setEndOfSourceStream();
        });
    } else {
        QObject::connect(source, &Source::newAudioBuffer, encoder, &Encoder::addBuffer,
                         Qt::DirectConnection);
    }
 
    // TODO:
    // QObject::connect(source, &Source::disconnectedFromSession, encoder, [=]() {
    //        encoder->setSourceEndOfStream();
    // });
 
    setEncoderUpdateConnection(source, encoder);
    setEncoderInterface(source, encoder);
}
 
void disconnectEncoderFromSource(EncoderThread *encoder);
 
} // namespace QFFmpeg
 
QT_END_NAMESPACE
 
#endif // QFFMPEGRECORDINGENGINEUTILS_P_H