video_decoder.h

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#ifndef VIDEO_DECODER_H
#define VIDEO_DECODER_H
 
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable: 4244 4267 4996)
#endif
 
#include <QBuffer>
#include <qmutex.h>
#include <QThread>
#include <QWaitCondition>
 
class AudioDecoder;
 
extern "C" {
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libswscale/swscale.h>
#include <libavutil/imgutils.h>
}
 
 
#ifdef _MSC_VER
#pragma warning(pop)
#endif

class VideoDecoder final : public QThread {
    Q_OBJECT
 
public:
    explicit VideoDecoder(const QByteArray &video_data, QObject *parent = nullptr);

    ~VideoDecoder() override;

    bool Initialize();

    void ExtractFirstFrame();

    void ReleaseResources() {
        CleanupFFmpegResources();
    }

    void Reset();

    void Stop();

    void Pause();

    void Seek(double position);

    void SetVolume(float volume) const;

    float GetVolume() const;

    bool IsPaused() const {
        QMutexLocker locker(&mutex_);
        return paused_;
    }

    bool HasAudio() const {
        return audio_stream_index_ != -1;
    }
 
signals:
    void frameReady(const QImage &frame);

    void videoInfo(int width, int height, double fps, double duration, bool has_audio);

    void positionChanged(double position);

    void playbackFinished();

    void error(const QString &message);
 
protected:
    void run() override;
 
private slots:
    void HandleAudioError(const QString &message) {
        emit error("Błąd strumienia audio: " + message);
    }

    void HandleAudioFinished();

    void UpdateAudioPosition(double position);
 
private:
    void CleanupFFmpegResources();

    static int ReadPacket(void *opaque, uint8_t *buf, int buf_size);

    static int64_t SeekPacket(void *opaque, int64_t offset, int whence);

    QByteArray video_data_;
    QBuffer buffer_;
    AVIOContext *io_context_ = nullptr;
    AVFormatContext *format_context_ = nullptr;
    AVCodecContext *codec_context_ = nullptr;
    SwsContext *sws_context_ = nullptr;
    AVFrame *frame_ = nullptr;
    int video_stream_ = -1;
    double frame_rate_ = 0.0;
    double duration_ = 0.0;
    double current_position_ = 0.0;

    mutable QMutex mutex_;
    QWaitCondition wait_condition_;
    bool stopped_ = false;
    bool paused_ = false;
    bool seeking_ = false;
    int64_t seek_position_ = -1;

    QElapsedTimer frame_timer_;
    bool first_frame_ = true;
    int64_t last_frame_pts_ = AV_NOPTS_VALUE;

    AudioDecoder *audio_decoder_ = nullptr;
    int audio_stream_index_ = -1;
    double current_audio_position_ = 0.0;
    bool audio_initialized_ = false;
    bool audio_finished_ = false;
    bool video_finished_ = false;
};
 
#endif // VIDEO_DECODER_H