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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 QFFMPEGTEXTURECONVERTER_P_H
++ #define QFFMPEGTEXTURECONVERTER_P_H
++
++ #include <QtFFmpegMediaPluginImpl/private/qffmpegdefs_p.h>
++ #include <QtMultimedia/private/qhwvideobuffer_p.h>
++
++ #include <memory>
++
++ //
++ // 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.
++ //
++
++ QT_BEGIN_NAMESPACE
++
++ class QRhi;
++
++ namespace QFFmpeg {
++
++ /**
++ * @brief The base class for platform-specific implementations of TextureConverter
++ * One of two virtual methods, createTextures and createTextureHandles, must be overridden.
++ * If the implementation operates with QRhiTexture under the hood, overriding of
++ * createTextures is prefferable, otherwise expose texture handles of native textures
++ * by createTextureHandles.
++ */
++ class TextureConverterBackend : public std::enable_shared_from_this<TextureConverterBackend>
++ {
++ public:
++ TextureConverterBackend(QRhi *rhi) : rhi(rhi) { }
++
++ virtual ~TextureConverterBackend();
++
++ virtual QVideoFrameTexturesUPtr createTextures(AVFrame * /*hwFrame*/,
++ QVideoFrameTexturesUPtr & /*oldTextures*/)
++ {
++ return nullptr;
++ }
++
++ virtual QVideoFrameTexturesHandlesUPtr
++ createTextureHandles(AVFrame * /*hwFrame*/, QVideoFrameTexturesHandlesUPtr /*oldHandles*/)
++ {
++ return nullptr;
++ }
++
++ /**
++ * @brief Points to the matching QRhi.
++ * If the constructor, createTextures, or createTextureHandles get failed without
++ * chances for recovery, it may set the pointer to nullptr, which will invalidate
++ * the parent TextureConverter, and textures creation won't be invoked anymore.
++ */
++ QRhi *rhi = nullptr;
++ };
++ using TextureConverterBackendPtr = std::shared_ptr<TextureConverterBackend>;
++
++ /**
++ * @brief The TextureConverter class implements conversion of AVFrame hw textures to
++ * textures for rendering by the specified QRhi. Any instance of TextureConverter
++ * matches the pair of FFmpeg hw frames context + QRhi.
++ */
++ class TextureConverter
++ {
++ public:
++ /**
++ * @brief Construct uninitialized texture converter for the specified QRhi
++ */
++ TextureConverter(QRhi &rhi);
++
++ /**
++ * @brief Initializes the instance of the texture converter for the frame context
++ * associated with the specified frame. The method tries to initialize
++ * the conversion backend during the first call with the specified frame format.
++ * If frame format is not changed, the method does nothing even if the first
++ * attempt failed.
++ * @return Whether the instance has been initialized.
++ */
++ bool init(AVFrame &hwFrame);
++
++ /**
++ * @brief Creates video frame textures basing on the current hw frame and the previous textures
++ * from the texture pool. We should strive to reuse oldTextures if we can do so.
++ * If the method returns null, try createTextureHandles.
++ */
++ QVideoFrameTexturesUPtr createTextures(AVFrame &hwFrame, QVideoFrameTexturesUPtr &oldTextures);
++
++ /**
++ * @brief Creates video frame texture handles basing on the current hw frame and the previous
++ * texture handles from the pool. We should strive to reuse oldHandles if we can do so.
++ */
++ QVideoFrameTexturesHandlesUPtr createTextureHandles(AVFrame &hwFrame,
++ QVideoFrameTexturesHandlesUPtr oldHandles);
++
++ /**
++ * @brief Indicates whether the texture converter is not initialized or the initialization
++ * failed. If hw texture conversion is disabled, it always true.
++ */
++ bool isNull() const { return !m_backend || !m_backend->rhi; }
++
++ /**
++ * @brief Applies platform-specific hw texture conversion presets for a decoder.
++ * The function is supposed to be invoked for the get_format callback.
++ */
++ static void applyDecoderPreset(AVPixelFormat format, AVCodecContext &codecContext);
++
++ /**
++ * @brief Indicates whether hw texture conversion is enabled for the application.
++ */
++ static bool hwTextureConversionEnabled();
++
++ /**
++ * @brief Indicates whether the matching textute converter backend can be created.
++ * If isBackendAvailable returns false, instances cannot be initialized with
++ * the specified frame. If it returns true, init will attempt to create backend,
++ * but it may fail if something goes wrong in the backend.
++ */
++ static bool isBackendAvailable(AVFrame &hwFrame, QRhi &rhi);
++
++ private:
++ void updateBackend(AVFrame &hwFrame);
++
++ private:
++ QRhi &m_rhi;
++ AVPixelFormat m_format = AV_PIX_FMT_NONE;
++ TextureConverterBackendPtr m_backend;
++ };
++
++ } // namespace QFFmpeg
++
++ QT_END_NAMESPACE
++
++ #endif // QFFMPEGTEXTURECONVERTER_P_H