Qt使用opencv，进行视频录制，功能打开、关闭摄像头，开始、结束录制视频，暂停、继续录制，并保存视频文件_qt+opencv摄像头录制视频并保存

1.效果图

2 代码实现

2.1 .h文件

#ifndef VIDEORECORDWIDGET_H
#define VIDEORECORDWIDGET_H
 
#include <QWidget>
 
#include<QFileDialog>
 
#include <QImage>
#include <QLabel>
#include <QTimer>
#include <opencv2/opencv.hpp>
 
using namespace cv;
namespace Ui {
class VideoRecordWidget;
}
 
class VideoRecordWidget : public QWidget
{
    Q_OBJECT
 
public:
    explicit VideoRecordWidget(QWidget *parent = nullptr);
    ~VideoRecordWidget();
 
private slots:
    void on_pushButton_clicked();
 
    void on_pushButton_2_clicked();
 
    void on_pushButton_3_clicked();
 
    void on_pushButton_5_clicked();
 
    void on_pushButton_4_clicked();
 
    void updateFrame();
 
    void on_pushButton_6_clicked();
 
private:
    Ui::VideoRecordWidget *ui;
 
    VideoCapture capture;
    // QTimer timer;
 
    VideoWriter videoWriter;
 
    bool m_video_open;
    bool m_video_record;
 
    QTimer timer_open;
    QTimer timer_record;
 
    String recordViedo_fileName;
 
 
};
 
#endif // VIDEORECORDWIDGET_H

2.2 .cpp文件

#include "videorecordwidget.h"
#include "ui_videorecordwidget.h"
 
VideoRecordWidget::VideoRecordWidget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::VideoRecordWidget)
{
    ui->setupUi(this);
 
    m_video_open=false;
    m_video_record=false;
 
    // connect(&timer, &QTimer::timeout, this, &VideoRecordWidget::updateFrame);
 
}
 
VideoRecordWidget::~VideoRecordWidget()
{
    delete ui;
}
 
//开启摄像头
void VideoRecordWidget::on_pushButton_clicked()
{
    // 打开摄像头
    capture.open(0);
    if (!capture.isOpened()) {
        qDebug("Failed to open camera.");
        return;
    }
 
    qDebug()<<"摄像头开启中";
    // 开始定时器，以固定间隔刷新显示视频图像
    timer_open.start(33); // 控制帧率为30fps
    m_video_open=true;
    connect(&timer_open, &QTimer::timeout, this, &VideoRecordWidget::updateFrame);
}
 
//关闭摄像头
void VideoRecordWidget::on_pushButton_2_clicked()
{
    // 关闭摄像头
    qDebug()<<"摄像头关闭中";
    capture.release();
    ui->label->clear();
    ui->label->setText("视频录制器");
    timer_open.stop();
    m_video_open=false;
 
    if(m_video_record){
        qDebug()<<"结束录制";
        m_video_record=false;
        timer_record.stop();
        videoWriter.release();
    }
 
 
}
 
 
//开始录制
void VideoRecordWidget::on_pushButton_3_clicked()
{
    if(m_video_open){
        if(videoWriter.isOpened()){
            qDebug()<<"已经有录制项目:"<<recordViedo_fileName<<"请先结束录制，再操作";
            return;
        }
        // 获取当前时间作为视频文件名
        std::time_t time = std::time(0);
        std::ostringstream oss;
        oss << "video_" << time << ".avi";
        recordViedo_fileName=oss.str();
        // std::string filename = oss.str();
 
        ui->lineEdit->setText(recordViedo_fileName.c_str());
 
 
        qDebug()<<"摄像头开启中-并进行录制,文件名:"<<recordViedo_fileName;
        timer_record.start(1000/25); // 控制帧率为30fps
        m_video_record=true;
 
        cv::Mat frame;
        capture >> frame; // 从视频流中捕获当前帧
 
        int codec = cv::VideoWriter::fourcc('M', 'J', 'P', 'G');
        double fps = 25.0;
        cv::Size frameSize(frame.cols, frame.rows);
        // if(videoWriter.isOpened()){
        //     videoWriter.write(frame);
        //     return;
        // }
        videoWriter.open(recordViedo_fileName, codec, fps, frameSize);
 
 
        connect(&timer_record, &QTimer::timeout, this, &VideoRecordWidget::updateFrame);
    }else{
        qDebug()<<"请先打开摄像头";
    }
 
 
}
 
//暂停录制
void VideoRecordWidget::on_pushButton_5_clicked()
{
    qDebug()<<"暂停录制";
    m_video_record=false;
 
}
 
//结束录制
void VideoRecordWidget::on_pushButton_4_clicked()
{
    qDebug()<<"结束录制";
    m_video_record=false;
    timer_record.stop();
    videoWriter.release();
 
}
 
void VideoRecordWidget::updateFrame()
{
    if(m_video_open){
        cv::Mat frame;
        capture >> frame; // 从视频流中捕获当前帧
 
        if (frame.empty()) {
            return;
        }
 
        // 将OpenCV的Mat图像转换为Qt的QImage
        QImage qimage(frame.data, frame.cols, frame.rows, static_cast<int>(frame.step), QImage::Format_BGR888);
        QPixmap pixmap = QPixmap::fromImage(qimage);
 
        // 设置QLabel显示图像
        ui->label->setPixmap(pixmap.scaled(ui->label->size(), Qt::KeepAspectRatio));
 
        if(m_video_record){
            qDebug()<<"录制中";
            // 创建 VideoWriter 对象
 
 
            // 检查是否成功打开视频文件
            if (!videoWriter.isOpened())
            {
                qDebug() << "无法打开视频文件.";
                return;
            }
            videoWriter.write(frame);
 
        }
 
    }
}
//继续录制
void VideoRecordWidget::on_pushButton_6_clicked()
{
    qDebug()<<"继续录制";
    m_video_record=true;
 
}