qffmpegvideoframeencoder_p.h

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// Copyright (C) 2022 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 QFFMPEGVIDEOFRAMEENCODER_P_H
#define QFFMPEGVIDEOFRAMEENCODER_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/qffmpeghwaccel_p.h>
#include <QtFFmpegMediaPluginImpl/private/qffmpegrecordingengineutils_p.h>
#include <QtMultimedia/private/qplatformmediarecorder_p.h>
#include <QtMultimedia/private/qmultimediautils_p.h>
 
 
QT_BEGIN_NAMESPACE
 
class QMediaEncoderSettings;
 
namespace QFFmpeg {
 
class VideoFrameEncoder;
using VideoFrameEncoderUPtr = std::unique_ptr<VideoFrameEncoder>;
 
class VideoFrameEncoder
{
public:
    struct SourceParams
    {
        QSize size;
        AVPixelFormat format = AV_PIX_FMT_NONE;
        AVPixelFormat swFormat = AV_PIX_FMT_NONE;
        VideoTransformation transform;
        qreal frameRate = 0.;
        AVColorTransferCharacteristic colorTransfer = AVCOL_TRC_UNSPECIFIED;
        AVColorSpace colorSpace = AVCOL_SPC_UNSPECIFIED;
        AVColorRange colorRange = AVCOL_RANGE_UNSPECIFIED;
    };
    static VideoFrameEncoderUPtr create(const QMediaEncoderSettings &encoderSettings,
                                        const SourceParams &sourceParams,
                                        AVFormatContext *formatContext);
 
    ~VideoFrameEncoder();
 
    AVPixelFormat sourceFormat() const { return m_sourceFormat; }
    AVPixelFormat targetFormat() const { return m_targetFormat; }
 
    qreal codecFrameRate() const;
 
    qint64 getPts(qint64 ms) const;
 
    const AVRational &getTimeBase() const;
 
    int sendFrame(AVFrameUPtr inputFrame);
    AVPacketUPtr retrievePacket();
 
private:
    VideoFrameEncoder(AVStream *stream, const Codec &codec, HWAccelUPtr hwAccel,
                      const SourceParams &sourceParams,
                      const QMediaEncoderSettings &encoderSettings);
 
    static AVStream *createStream(const SourceParams &sourceParams, AVFormatContext *formatContext);
 
    bool updateSourceFormatAndSize(const AVFrame *frame);
 
    void updateConversions();
 
    struct CreationResult
    {
        VideoFrameEncoderUPtr encoder;
        AVPixelFormat targetFormat = AV_PIX_FMT_NONE;
    };
 
    static CreationResult create(AVStream *stream, const Codec &codec, HWAccelUPtr hwAccel,
                                 const SourceParams &sourceParams,
                                 const QMediaEncoderSettings &encoderSettings,
                                 const AVPixelFormatSet &prohibitedTargetFormats = {});
 
    void initTargetSize();
 
    void initCodecFrameRate();
 
    bool initTargetFormats(const AVPixelFormatSet &prohibitedTargetFormats);
 
    void initStream();
 
    bool initCodecContext();
 
    bool open();
 
    qint64 estimateDuration(const AVPacket &packet, bool isFirstPacket);
 
private:
    const QMediaEncoderSettings m_settings;
    AVStream *const m_stream = nullptr;
    const Codec m_codec;
    const HWAccelUPtr m_accel;
 
    QSize m_sourceSize;
    QSize m_targetSize;
 
    qint64 m_lastPacketTime = AV_NOPTS_VALUE;
    AVCodecContextUPtr m_codecContext;
    SwsContextUPtr m_scaleContext;
    AVPixelFormat m_sourceFormat = AV_PIX_FMT_NONE;
    AVPixelFormat m_sourceSWFormat = AV_PIX_FMT_NONE;
    AVPixelFormat m_targetFormat = AV_PIX_FMT_NONE;
    AVPixelFormat m_targetSWFormat = AV_PIX_FMT_NONE;
    bool m_downloadFromHW = false;
    bool m_uploadToHW = false;
 
    qreal m_sourceFrameRate = 0.f; // 0 = variable/unknown
    AVRational m_codecFrameRate = { 0, 1 };
 
    // m_codecFrameRate as fed to AVCodecContext::framerate and used to derive the
    // stream time base. Unlike m_codecFrameRate (which stays {0, 1} for a genuinely
    // variable-rate stream), this is never zero
    AVRational effectiveCodecFrameRate() const
    {
        return m_codecFrameRate.den > 0 && m_codecFrameRate.num > 0
                ? m_codecFrameRate
                : AVRational{ DefaultVideoFrameRate, 1 };
    }
 
    int64_t m_prevPacketDts = AV_NOPTS_VALUE;
    int64_t m_packetDtsOffset = 0;
};
} // namespace QFFmpeg
 
QT_END_NAMESPACE
 
#endif