在pro中加入两个qmake: QT += multimedia QT += multimediawidgets

头文件

#include //导入摄像头类#include //摄像头信息类#include //取景器类#include //捕获类#include //摄像头设置类QList list;list = QCameraInfo::availableCameras(); //返回摄像头信息列表qDebug()<setCaptureMode(QCamera::CaptureStillImage);//设置捕获模式/*QCamera::CaptureStillImage=0x01捕捉静止帧QCamera::CaptureViewfinder=0仅配置为显示取景器QCamera::CaptureVideo=0x02配置为视频捕获*/int cm=camera->captureMode(); //返回当前捕获模式qDebug()<<"当前捕获模式"<isCaptureModeSupported(QCamera::CaptureStillImage);//是否支持指定的模式qDebug()<

实例一

win.h

QT开发交流+赀料君羊：714620761

#ifndef WIN_H#define WIN_H#include #include #include #include #include #include #include class win : public QWidget{Q_OBJECTpublic:win(QWidget *parent = nullptr);~win();private:QCamera *camera; //摄像头对象QCameraViewfinder *viewfinder;//取景器QCameraImageCapture *imageCapture;//捕获对象QPushButton* buttonCapture;QLabel* ImageCapture;private slots:void captureImage();void displayImage(int,QImage);};#endif // WIN_H

#include "win.h"win::win(QWidget *parent): QWidget(parent){buttonCapture=new QPushButton("捕获",this);buttonCapture->move(700,400);ImageCapture=new QLabel("显示图片",this);ImageCapture->resize(320,240);ImageCapture->move(700,0);camera=new QCamera(this);viewfinder=new QCameraViewfinder(this);//创建取景器//取景器用来预览viewfinder->resize(640,480);viewfinder->move(0,0);//这个取景器的0点不是窗口的0点？？imageCapture=new QCameraImageCapture(camera);//捕获对象camera->setViewfinder(viewfinder);//设置取景器//start()开启摄像头后，取景器会自动从摄像头读取图片，但imageCapture没有捕获camera->start();//ui->ImageCapture->setScaledContents(true);//图片随着标签大小而变化connect(imageCapture, SIGNAL(imageCaptured(int,QImage)), this, SLOT(displayImage(int,QImage)));//imageCapture捕获到新图时，会发出imageCaptured(int,QImage)信号//int id 第几次捕获；QImage捕获的图像connect(buttonCapture, SIGNAL(clicked()), this, SLOT(captureImage()));}win::~win(){}void win::captureImage(){imageCapture->capture();//捕获图片//imageCapture捕获到新图时，会发出imageCaptured(int,QImage)信号}void win::displayImage(int id, QImage image){qDebug()<size();//返回显示框大小qDebug()<setPixmap(QPixmap::fromImage(image));}

判断是否被占用

//检测摄像头是否被占用QCamera *m_pCamera = new QCamera(this);QCameraViewfinder *m_pViewfinder = new QCameraViewfinder(this);//取景器QCameraImageCapture *m_pImageCapture = new QCameraImageCapture(m_pCamera);//捕获对象m_pImageCapture->setCaptureDestination(QCameraImageCapture::CaptureToFile);//设置捕获为文件或者缓冲区，默认为文件m_pCamera->setCaptureMode(QCamera::CaptureStillImage);//设置捕获模式m_pCamera->setViewfinder(m_pViewfinder);//设置取景器m_pCamera->start();if (!m_pImageCapture->isReadyForCapture())//摄像头是否准备好捕获了{qDebug() << "摄像头已被其他应用程序占用";QMessageBox box(QMessageBox::Question, tr("提示"), tr("摄像头打开失败。"));box.addButton(tr("确 定"), QMessageBox::YesRole);box.ｅｘｅｃ();}m_pCamera->stop();ｄｅｌｅｔｅ m_pCamera;ｄｅｌｅｔｅ m_pViewfinder;ｄｅｌｅｔｅ m_pImageCapture;

QCameraInfo

QList list;list = QCameraInfo::availableCameras(); //返回摄像头信息列表qDebug()<

分辨率、帧率

查询和设置摄像头分辨率时，需要在摄像头启动后调用，

即在调用QCamera:：start（）后，

可以使用QCamera:：stateChanged（QCamera:State state）信号，

如果收到摄像头状态为QCamera:：ActiveState后，再调用上述API

camera=new QCamera(this);viewfinder=new QCameraViewfinder(this);viewfinder->resize(640,480);viewfinder->move(0,0);camera->setViewfinder(viewfinder);camera->start();QList ViewSets = camera->supportedViewfinderSettings();//获取摄像头支持的分辨率、帧率等参数qDebug() << ViewSets.length();//返回分辨率支持的总数//14foreach (QCameraViewfinderSettings ViewSet, ViewSets) {qDebug() << i++ <<"最大帧速率=" << ViewSet.maximumFrameRate() << "最小帧速率="<< ViewSet.minimumFrameRate() << "分辨率:"<setViewfinderSettings(ViewSets[1]);//设置摄像头参数qreal maxrate=ViewSets[0].maximumFrameRate();//返回最大帧速率qreal minrate=ViewSets[0].minimumFrameRate();//返回最小帧速率qDebug() <

相机状态

camera=new QCamera(this);viewfinder=new QCameraViewfinder(this);viewfinder->resize(640,480);viewfinder->move(0,0);camera->setViewfinder(viewfinder);camera->start();int n=camera->status(); //返回相机当前状态/*QCamera::ActiveStatus=8摄像机已经启动，可以生成数据。取景器在活动状态下显示视频帧。 说明:根据后端的不同，在ActiveState中更改某些相机设置（如捕获模式、编解码器或分辨率） 可能会导致在应用设置时将相机状态更改为LoadedStatus和StartingStatus，并在相机准备 就绪时将相机状态更改为ActiveStatusQCamera::StartingStatus=6状态正在转换为QCamera:：ActiveState，相机正在启动。相机服务尚未准备好拍摄QCamera::StoppingStatus=7状态从QCamera:：ActiveState转换为QCamera:：LoadedState或QCamera:：UnloadedState，相机正在停止QCamera::StandbyStatus=5相机处于省电待机模式。相机在QCamera:：LoadedState状态下静止一段时间后可能会进入待机模式QCamera::StandbyStatus=4摄像机已加载并准备好进行配置。此状态表示相机设备已打开，可以查询支持的图像和视频捕获设置，如分辨率、帧速率和编解码器QCamera::StandbyStatus=3状态从QCamera:：LoadedState或QCamera:：ActiveState转换为QCamera:：UnloadedState，相机设备正在卸载QCamera::StandbyStatus=2状态从QCamera:：UnloadedState转换为QCamera:：LoadedState或QCamera:：ActiveState，相机设备加载QCamera::StandbyStatus=1相机未加载时的初始相机状态QCamera::StandbyStatus=0相机或相机后端不可用*/qDebug()<