////////////////////////////////////////mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QMediaPlayer>
#include <QVideoWidget>
#include <QFileDialog>
#include <QVBoxLayout>
#include "myvideoobject.h"


namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:
    void on_actionOpen_triggered();

private:
    Ui::MainWindow *ui;

    QMediaPlayer* mediaPlayer;
    QVideoWidget* videoWidget;
    MyVideoObject* videoObject;

};

#endif // MAINWINDOW_H


///////////////////////////////////////////////////////mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    mediaPlayer = new QMediaPlayer(this);

    videoObject = new MyVideoObject(this);
    ui->horizontalLayout_5->addWidget(videoObject);
    videoObject->resize(500,400);
    mediaPlayer->setVideoOutput(videoObject);
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::on_actionOpen_triggered()
{
    QString fileName = QFileDialog::getOpenFileName(this,"Select Video","","video Files (*.mp4)");

    mediaPlayer->stop();
    mediaPlayer->setMedia(QUrl::fromLocalFile(fileName));

    mediaPlayer->play();

}
///////////////////////////////////////////////////////////// main.cpp


#include "mainwindow.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}