qffmpegdemuxer_p.h

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// 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
#ifndef QFFMPEGDEMUXER_P_H
#define QFFMPEGDEMUXER_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 <QtFFmpegMediaPluginImpl/private/qffmpegplaybackengineobject_p.h>
#include <QtFFmpegMediaPluginImpl/private/qffmpegpacket_p.h>
#include <QtFFmpegMediaPluginImpl/private/qffmpegplaybackutils_p.h>
#include <QtFFmpegMediaPluginImpl/private/qffmpegtime_p.h>
#include <QtMultimedia/private/qplatformmediaplayer_p.h>
 
#include <unordered_map>
 
QT_BEGIN_NAMESPACE
 
namespace QFFmpeg {
 
class Demuxer : public PlaybackEngineObject
{
    Q_OBJECT
public:
    Demuxer(const PlaybackEngineObjectID &id, AVFormatContext *context, TrackPosition initialPosUs,
            bool seekPending, const LoopOffset &loopOffset, const StreamIndexes &streamIndexes,
            int loops);
 
    void seek(quint64 sessionId, TrackPosition initialPosUs, const LoopOffset &loopOffset);
 
    using RequestingSignal = void (Demuxer::*)(Packet);
    static RequestingSignal signalByTrackType(QPlatformMediaPlayer::TrackType trackType);
 
    void setLoops(int loopsCount);
 
public slots:
    void onPacketProcessed(Packet);
 
signals:
    void requestProcessAudioPacket(Packet);
    void requestProcessVideoPacket(Packet);
    void requestProcessSubtitlePacket(Packet);
    void firstPacketFound(PlaybackEngineObjectID id, TrackPosition absSeekPos);
    void packetsBuffered();
 
protected:
    TimePoint nextTimePoint() const override;
 
private:
    bool canDoNextStep() const override;
 
    void doNextStep() override;
 
    void ensureSeeked();
 
private:
    struct StreamData
    {
        QPlatformMediaPlayer::TrackType trackType = QPlatformMediaPlayer::TrackType::NTrackTypes;
        TrackDuration bufferedDuration = TrackDuration(0);
        qint64 bufferedSize = 0;
 
        TrackPosition maxSentPacketsPos = TrackPosition(0);
        TrackPosition maxProcessedPacketPos = TrackPosition(0);
 
        bool isDataLimitReached = false;
    };
 
    void updateStreamDataLimitFlag(StreamData &streamData);
 
private:
    AVFormatContext *m_context = nullptr;
 
    struct SessionContext
    {
        TrackPosition posInLoopUs = TrackPosition(0); // Position in current loop in [0, duration()]
        LoopOffset loopOffset = {};
        bool seeked = false;
        bool firstPacketFound = false;
        bool buffered = false;
        TrackPosition maxPacketsEndPos = TrackPosition(0);
 
        qsizetype demuxerRetryCount = 0;
        std::optional<TimePoint> failTimePoint = {};
    };
 
    SessionContext m_sessionCtx;
    std::unordered_map<int, StreamData> m_streams;
    QAtomicInt m_loops = QMediaPlayer::Once;
 
    static constexpr qsizetype s_maxDemuxerRetries = 10; // Arbitrarily chosen
    static constexpr std::chrono::milliseconds s_demuxerRetryInterval = std::chrono::milliseconds(10);
};
 
} // namespace QFFmpeg
 
QT_END_NAMESPACE // QFFMPEGDEMUXER_P_H
 
#endif