libopenshot/src/CVStabilization.h

/**
 * @file
 * @brief Header file for CVStabilization class
 * @author Jonathan Thomas <jonathan@openshot.org>
 * @author Brenno Caldato <brenno.caldato@outlook.com>
 *
 * @ref License
 */

// Copyright (c) 2008-2019 OpenShot Studios, LLC
//
// SPDX-License-Identifier: LGPL-3.0-or-later

#ifndef OPENSHOT_STABILIZATION_H
#define OPENSHOT_STABILIZATION_H

#define int64 opencv_broken_int
#define uint64 opencv_broken_uint
#include <opencv2/opencv.hpp>
#include <opencv2/core.hpp>
#undef uint64
#undef int64

#include <map>
#include <string>
#include <vector>

#include "ProcessingController.h"

#include "Clip.h"
#include "Json.h"

// Forward decl
namespace pb_stabilize {
    class Frame;
}

// Store the relative transformation parameters between consecutive frames
struct TransformParam
{
    TransformParam() {}
    TransformParam(double _dx, double _dy, double _da) {
        dx = _dx;
        dy = _dy;
        da = _da;
    }

    double dx;
    double dy;
    double da; // angle
};

// Stores the global camera trajectory for one frame
struct CamTrajectory
{
    CamTrajectory() {}
    CamTrajectory(double _x, double _y, double _a) {
        x = _x;
        y = _y;
        a = _a;
    }

    double x;
    double y;
    double a; // angle
};


/**
 * @brief This class stabilizes a video frame using optical flow
 *
 * The relative motion between two consecutive frames is computed to obtain the global camera trajectory.
 * The camera trajectory is then smoothed to reduce jittering.
 */
class CVStabilization {

    private:

    int smoothingWindow; // In frames. The larger the more stable the video, but less reactive to sudden panning

    size_t start;
    size_t end;
    double avr_dx, avr_dy, avr_da, max_dx, max_dy, max_da;

    cv::Mat last_T;
    cv::Mat prev_grey;
    std::vector <TransformParam> prev_to_cur_transform; // Previous to current
    std::string protobuf_data_path;

    uint progress;
    bool error = false;

    /// Will handle a Thread safely comutication between ClipProcessingJobs and the processing effect classes
    ProcessingController *processingController;

    /// Track current frame features and find the relative transformation
    bool TrackFrameFeatures(cv::Mat frame, size_t frameNum);

    std::vector<CamTrajectory> ComputeFramesTrajectory();
    std::map<size_t,CamTrajectory> SmoothTrajectory(std::vector <CamTrajectory> &trajectory);

    /// Generate new transformations parameters for each frame to follow the smoothed trajectory
    std::map<size_t,TransformParam> GenNewCamPosition(std::map <size_t,CamTrajectory> &smoothed_trajectory);

    public:

    std::map <size_t,CamTrajectory> trajectoryData; // Save camera trajectory data
    std::map <size_t,TransformParam> transformationData; // Save transormation data

    /// Set default smoothing window value to compute stabilization
    CVStabilization(std::string processInfoJson, ProcessingController &processingController);

    /// Process clip and store necessary stabilization data
    void stabilizeClip(openshot::Clip& video, size_t _start=0, size_t _end=0, bool process_interval=false);

    /// Protobuf Save and Load methods
    /// Save stabilization data to protobuf file
    bool SaveStabilizedData();
    /// Add frame stabilization data into protobuf message
    void AddFrameDataToProto(pb_stabilize::Frame* pbFrameData, CamTrajectory& trajData, TransformParam& transData, size_t frame_number);

    // Return requested struct info for a given frame
    TransformParam GetTransformParamData(size_t frameId);
    CamTrajectory GetCamTrajectoryTrackedData(size_t frameId);

    // Get and Set JSON methods
    void SetJson(const std::string value); ///< Load JSON string into this object
    void SetJsonValue(const Json::Value root); ///< Load Json::Value into this object

    // Load protobuf data file (ONLY FOR MAKE TEST)
    bool _LoadStabilizedData();
};

#endif