Qt6实现调用摄像头并显示画面

find_package(QT NAMES Qt6 Qt5 REQUIRED COMPONENTS Widgets)
find_package(Qt${QT_VERSION_MAJOR} REQUIRED COMPONENTS Widgets)
find_package(Qt6 COMPONENTS Multimedia REQUIRED)
find_package(Qt6 COMPONENTS MultimediaWidgets REQUIRED)
 
target_link_libraries(samon1 PRIVATE Qt${QT_VERSION_MAJOR}::Widgets)
target_link_libraries(samon1 PRIVATE Qt6::Multimedia)
target_link_libraries(samon1 PRIVATE Qt6::MultimediaWidgets)
set_target_properties(samon1 PROPERTIES

set(PROJECT_SOURCES
        main.cpp
        camera.cpp
        camera.h
        camera.ui
)

#include <QApplication>//Qt必要头文件
 
#include "camera.h"//摄像头
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);//Qt初始化
 
    Camera w;//创建窗口类
    w.setWindowTitle("Camera");//设置窗口标题
    w.show();//显示窗口
 
    return a.exec();//程序结束
}

#include "camera.h"//摄像头
#include "./ui_camera.h"//CMakeLists.txt构建后产生文件
 
Camera::Camera(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::Camera)
{
    ui->setupUi(this);
 
    //qDebug("Camera Device Check:%d",Camera::checkCameraAvailability());//摄像头驱动检测debug测试
 
    my_camera.reset(new QCamera(QMediaDevices::defaultVideoInput()));//新建并设置摄像头使用默认驱动
    my_captureSession.setCamera(my_camera.data());//捕获摄像头画面
    my_captureSession.setVideoOutput(ui->viewfinder);//设置捕捉画面显示窗口
    my_camera->start();//启动摄像头
 
}
 
 
//检测摄像头驱动能否识别
bool Camera::checkCameraAvailability()
{
    if (QMediaDevices::videoInputs().count() > 0)
        return true;//检测到摄像头驱动
    else
        return false;//没有检测到摄像头驱动
}
 
//消类
Camera::~Camera()
{
    delete ui;
}

//icysamon@outlook.com
 
#ifndef CAMERA_H
#define CAMERA_H
 
#include <QMainWindow>
#include <QCamera>
#include <QVideoWidget>
#include <QMediaCaptureSession>
#include <QMediaDevices>
#include <QImageCapture>
#include <QMediaRecorder>
 
 
QT_BEGIN_NAMESPACE
namespace Ui { class Camera; }
QT_END_NAMESPACE
 
 
class Camera : public QMainWindow
{
    Q_OBJECT
 
public:
    Camera(QWidget *parent = nullptr);
    ~Camera();
 
private:
    Ui::Camera *ui;
    QScopedPointer<QCamera> my_camera;
    QScopedPointer<QMediaRecorder> my_mediaRecorder;
    QMediaCaptureSession my_captureSession;
 
    bool checkCameraAvailability(void);
 
};
#endif // CAMERA_H 

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>Camera</class>
 <widget class="QMainWindow" name="Camera">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>762</width>
    <height>567</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QVideoWidget" name="viewfinder"/>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>762</width>
     <height>26</height>
    </rect>
   </property>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <customwidgets>
  <customwidget>
   <class>QVideoWidget</class>
   <extends>QWidget</extends>
   <header location="global">qvideowidget.h</header>
   <container>1</container>
  </customwidget>
 </customwidgets>
 <resources/>
 <connections/>
</ui>