Use OpencV to play MP4 files on Qt control

The header file

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QTimer>
#include "opencv2/opencv.hpp"
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/imgproc/types_c.h>
#include <opencv2/highgui.hpp>
#include <opencv2/video.hpp>

using namespace std;
using namespace cv;


namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

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

private slots:
    void on_play_clicked(a);
    void playTimer(a);

    void on_stop_clicked(a);

private:
    Ui::MainWindow *ui;
    QTimer *m_pTimer;
    VideoCapture *m_pVideo;
};

#endif // MAINWINDOW_H
Copy the code

The implementation code

CvtColor (frame, frame, COLOR_BGR2RGB); cvtColor(frame, frame, COLOR_BGR2RGB); QImage disImage = QImage((const unsigned) char*)(frame.data),frame.cols,frame.rows,frame.cols*frame.channels(),QImage::Format_RGB888); ui->label->setPixmap(QPixmap::fromImage(disImage)); // Display the image

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/imgproc/types_c.h>
using namespace cv;
using namespace std;

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    m_pTimer = new QTimer;
    m_pTimer->setInterval(30);  // Time 30 ms to read a frame of data
    connect(m_pTimer, &QTimer::timeout, this, &MainWindow::playTimer);

    ui->play->setEnabled(true);
    ui->stop->setEnabled(false);

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

void MainWindow::playTimer(a)
{
    Mat frame;

    // Read a frame from cap and store it in FRAM
    *m_pVideo >> frame;
    if ( frame.empty()) {return;
    }
    cv::cvtColor(frame, frame, COLOR_BGR2RGB);// Image format conversion
    QImage disImage = QImage((const unsigned char*)(frame.data),frame.cols,frame.rows,frame.cols*frame.channels(),QImage::Format_RGB888);
    ui->label->setPixmap(QPixmap::fromImage(disImage));// Display the image
}

void MainWindow::InitVideo(a)
{
    m_pVideo = new VideoCapture("test.mp4");

}

void MainWindow::on_play_clicked(a)
{
    m_pTimer->start(a); ui->play->setEnabled(false);
    ui->stop->setEnabled(true);

}

void MainWindow::on_stop_clicked(a)
{
    ui->play->setEnabled(true);
    ui->stop->setEnabled(false);

    m_pTimer->stop(a); }Copy the code

controls

For testing, the interface is relatively simple, the middle is a QLabel, the following two keys for control playback.