qffmpeghwaccel_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 QFFMPEGHWACCEL_P_H
#define QFFMPEGHWACCEL_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/qffmpeg_p.h>
#include <QtFFmpegMediaPluginImpl/private/qffmpegtextureconverter_p.h>
#include <QtMultimedia/qvideoframeformat.h>
#include <QtMultimedia/private/qhwvideobuffer_p.h>
#include <QtMultimedia/private/qrhivaluemapper_p.h>
#include <QtCore/qspan.h>
 
#include <memory>
#include <mutex>
 
QT_BEGIN_NAMESPACE
 
class QRhi;
class QRhiTexture;
class QFFmpegVideoBuffer;
 
namespace QFFmpeg {
 
// used for the get_format callback for the decoder
AVPixelFormat getFormat(AVCodecContext *s, const AVPixelFormat *fmt);
 
class HWAccel;
 
class HWAccel;
using HWAccelUPtr = std::unique_ptr<HWAccel>;
 
/**
 * @brief The HwFrameContextData class contains custom belongings
 *        of hw frames context.
 */
struct HwFrameContextData
{
    using AVHWFramesContextDeleter = void (*)(struct AVHWFramesContext *ctx);
    AVHWFramesContextDeleter avDeleter = nullptr;
    void *avUserOpaque = nullptr;
 
    QRhiValueMapper<TextureConverter> textureConverterMapper = {};
 
    /**
     * @brief gets or creates an instance of the class, associated with
     *        the frames context of the specified frame. Note, AVFrame
     *        holds shared ownership of the frames context, so consider this
     *        when designing HwFrameContextData's lifetime.
     */
    static HwFrameContextData &ensure(AVFrame &hwFrame);
};
 
class HWAccel
{
    const AVBufferUPtr m_hwDeviceContext;
    AVBufferUPtr m_hwFramesContext;
 
    mutable std::once_flag m_constraintsOnceFlag;
    mutable AVHWFramesConstraintsUPtr m_constraints;
 
public:
    ~HWAccel();
 
    static HWAccelUPtr create(AVHWDeviceType deviceType);
 
    static std::pair<std::optional<Codec>, HWAccelUPtr> findDecoderWithHwAccel(AVCodecID id);
 
    AVHWDeviceType deviceType() const;
 
    AVBufferRef *hwDeviceContextAsBuffer() const { return m_hwDeviceContext.get(); }
    AVHWDeviceContext *hwDeviceContext() const;
    AVPixelFormat hwFormat() const;
    const AVHWFramesConstraints *constraints() const;
 
    bool matchesSizeContraints(QSize size) const;
 
    void createFramesContext(AVPixelFormat swFormat, const QSize &size);
    void destroyFramesContext();
    void updateFramesContext(AVPixelFormat swFormat, const QSize &size);
    AVBufferRef *hwFramesContextAsBuffer() const { return m_hwFramesContext.get(); }
    AVHWFramesContext *hwFramesContext() const;
 
    static AVPixelFormat format(AVFrame *frame);
    static QSpan<const AVHWDeviceType> encodingDeviceTypes();
    static QSpan<const AVHWDeviceType> decodingDeviceTypes();
 
private:
    HWAccel(AVBufferUPtr hwDeviceContext) : m_hwDeviceContext(std::move(hwDeviceContext)) { }
};
 
AVFrameUPtr copyFromHwPool(AVFrameUPtr frame);
 
} // namespace QFFmpeg
 
QT_END_NAMESPACE
 
#endif