QT学习_QT摄像头使用

Posted 2021-06-30 Leslie X徐

QT摄像头使用

mplayer

使用 mplayer tv:// 命令打开摄像头

void Widget::on_pushButton_4_clicked()
{
    QStringList args;
    args << "tv://";
    args << "-wid";
    args << QString::number(ui->widget->winId());
    process->start("mplayer", args); //启动该进程，并传入参数args
    ui->pushButton_4->setDisabled(true);
}

QCamera

首先需要以下库工具

sudo apt-get install qtmultimedia5-dev
sudo apt-get install libqt5multimedia5-plugins

显示:

pro文件

QT       += core gui multimedia multimediawidgets

头文件
使用到的类有：
- QCamera
- QCameraInfo
- QCameraViewfinder

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QCamera>
#include <QCameraInfo>
#include <QList>
#include <QCameraViewfinder>


namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

    QCamera *curCamera=Q_NULLPTR;

    void initCamera();

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

private slots:
    void on_actionStartCamera_triggered();

    void on_actionStopCamera_triggered();

    void on_actionQuit_triggered();

private:
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

源文件

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>

void MainWindow::initCamera()
{
    QCameraInfo curCameraInfo = QCameraInfo::defaultCamera();//获取缺省摄像头
    ui->comboBox->addItem(curCameraInfo.description());
    ui->comboBox->setCurrentIndex(0);

    curCamera = new QCamera(curCameraInfo,this);
    QCameraViewfinderSettings vfs;
    //vfs.setResolution(ui->widget->size());
    vfs.setResolution(640,480);
    curCamera->setViewfinderSettings(vfs);
    curCamera->setViewfinder(ui->widget);
}

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

    QList<QCameraInfo> cameras = QCameraInfo::availableCameras();
    if(cameras.size()>0){
        initCamera();
    }

}

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

void MainWindow::on_actionStartCamera_triggered()
{
    curCamera->start();
}

void MainWindow::on_actionStopCamera_triggered()
{
    curCamera->stop();
}

void MainWindow::on_actionQuit_triggered()
{
    curCamera->stop();
    this->close();
}