Qt 基于海康相机的视频绘图

需求

在视频窗口上进行绘图，包括圆，矩形，扇形等

效果：

思路：

自己取图然后转成QImage ，再向QWidget 进行渲染，根据以往的经验，无法达到很高的帧率。因此决定使用相机SDK自带的渲染功能，也就是传一个句柄给到sdk。但是这样视频渲染出来了，向上绘制图案，会被视频遮挡住，因此这里采用了两个窗口叠加，然后上层窗口设置透明背景的方式来实现。

底层取图窗口代码：

#ifndef CAMERAWIDGET_H
#define CAMERAWIDGET_H

#include <QWidget>
#include <windows.h>
#include <MvCameraControl.h>

#include "./util/PSEventController.h"
#include "graphwidget.h"
class CameraWidget : public QWidget
{
    Q_OBJECT
public:
    explicit CameraWidget(QWidget *parent = nullptr);
    ~CameraWidget();

    void updatePos(int x,int y);

private:
    bool findDevice();
    bool printDeviceInfo(MV_CC_DEVICE_INFO* pstMVDevInfo);
    void getImage();
    bool openDevice();
    bool closeDevice();

private:
    int nRet = MV_OK;
    void* handle = NULL;
    MV_CC_DEVICE_INFO_LIST stDeviceList = {0};
    std::atomic_bool bExit = true;
    HWND hwnd = NULL;

    GraphWidget * graphWidget=nullptr;
    QWidget *videoWidget =nullptr;

    std::atomic_bool isCapture{false};

private:
    void initData();
    void mvToQImage(MV_DISPLAY_FRAME_INFO &stDisplayInfo);

public slots:
    void on_psEvent_capture(bool isChecked);
    void on_psEvent_adjustImage(bool isChecked);
    void on_psEvent_fixImage(bool isChecked);

signals:
    void capture(QImage image);
};

#endif // CAMERAWIDGET_H


#include "camerawidget.h"

#include <iostream>
#include <mutex>
#include <thread>
#include <QWidget>
#include <QPainter>
#include <QGridLayout>
#include <QStackedLayout>
#include <QDebug>
#include <QGraphicsScene>
#include <QGraphicsView>
#include <QGraphicsItem>

CameraWidget::CameraWidget(QWidget *parent)
    : QWidget{parent}
{
    graphWidget = new GraphWidget(this);
    graphWidget->setWindowFlags(Qt::FramelessWindowHint|Qt::Dialog|Qt::WindowStaysOnTopHint|Qt::SubWindow);
    graphWidget->setAttribute(Qt::WA_TranslucentBackground, true);
    QPalette pal;
    pal.setColor(QPalette::Window,QColor(0,0,0,0));
    graphWidget->setAutoFillBackground(true);
    graphWidget->setPalette(pal);
    graphWidget->show();

    hwnd = (HWND)this->winId();
    openDevice();

    this->setFixedSize(816,683);
    graphWidget->setFixedSize(this->size());

    setUpdatesEnabled(false);
    setAttribute(Qt::WA_OpaquePaintEvent);

    initData();
}

CameraWidget::~CameraWidget()
{
    closeDevice();
}


bool CameraWidget::findDevice()
{
    //枚举设备
    nRet = MV_CC_EnumDevices(MV_GIGE_DEVICE | MV_USB_DEVICE, &stDeviceList);
    if (MV_OK != nRet)
    {
        printf("Enum Devices fail! nRet [0x%x]\n", nRet);
        return false;
    }

    if (stDeviceList.nDeviceNum > 0)
    {
        for (unsigned int i = 0; i < stDeviceList.nDeviceNum; i++)
        {
            printf("[device %d]:\n", i);
            MV_CC_DEVICE_INFO* pDeviceInfo = stDeviceList.pDeviceInfo[i];
            if (NULL == pDeviceInfo)
            {
                break;
            }
            printDeviceInfo(pDeviceInfo);
        }
    }
    else
    {
        printf("Find No Devices!\n");
        return false;
    }
    return true;
}

bool CameraWidget::openDevice()
{
    if(!findDevice()){
        return false;
    }

    unsigned int nIndex = 0;
    if (nIndex >= stDeviceList.nDeviceNum)
    {
        printf("Invalid device index!\n");
        return false;
    }

    do
    {
        //选择设备并创建句柄
        nRet = MV_CC_CreateHandle(&handle, stDeviceList.pDeviceInfo[nIndex]);
        if (MV_OK != nRet)
        {
            printf("Create Handle fail! nRet [0x%x]\n", nRet);
            break;
        }

        // ch:打开设备
        nRet = MV_CC_OpenDevice(handle);
        if (MV_OK != nRet)
        {
            printf("Open Device fail! nRet [0x%x]\n", nRet);
            break;
        }

        // ch:探测网络最佳包大小(只对GigE相机有效)
        if (stDeviceList.pDeviceInfo[nIndex]->nTLayerType == MV_GIGE_DEVICE)
        {
            int nPacketSize = MV_CC_GetOptimalPacketSize(handle);
            if (nPacketSize > 0)
            {
                nRet = MV_CC_SetIntValue(handle,"GevSCPSPacketSize",nPacketSize);
                if(nRet != MV_OK)
                {
                    printf("Warning: Set Packet Size fail nRet [0x%x]!", nRet);
                }
            }
            else
            {
                printf("Warning: Get Packet Size fail nRet [0x%x]!", nPacketSize);
            }
        }

        //设置触发模式为off
        nRet = MV_CC_SetEnumValue(handle, "TriggerMode", 0);
        if (MV_OK != nRet)
        {
            printf("Set Trigger Mode fail! nRet [0x%x]\n", nRet);
            break;
        }

        // ch:开始取流 | en:Start grab image
        nRet = MV_CC_StartGrabbing(handle);
        if (MV_OK != nRet)
        {
            printf("Start Grabbing fail! nRet [0x%x]\n", nRet);
            break;
        }
        bExit=false;

        std::thread t([&](){
            getImage();
        });
        t.detach();

        return true;
    }while (0);


    if (nRet != MV_OK)
    {
        if (handle != NULL)
        {
            MV_CC_DestroyHandle(handle);
            handle = NULL;
        }
    }

    return false;
}

bool CameraWidget::closeDevice()
{
    bExit=true;

    if (handle == NULL)
        return true;

    do{
        // ch:停止取流 | en:Stop grab image
        nRet = MV_CC_StopGrabbing(handle);
        if (MV_OK != nRet)
        {
            printf("Stop Grabbing fail! nRet [0x%x]\n", nRet);
            break;
        }

        // ch:关闭设备 | Close device
        nRet = MV_CC_CloseDevice(handle);
        if (MV_OK != nRet)
        {
            printf("ClosDevice fail! nRet [0x%x]\n", nRet);
            break;
        }

        // ch:销毁句柄 | Destroy handle
        nRet = MV_CC_DestroyHandle(handle);
        if (MV_OK != nRet)
        {
            printf("Destroy Handle fail! nRet [0x%x]\n", nRet);
            break;
        }

        handle = NULL;
        return true;
    }while (0);

    if (nRet != MV_OK)
    {
        if (handle != NULL)
        {
            MV_CC_DestroyHandle(handle);
            handle = NULL;
        }
    }

    return false;
}

void CameraWidget::initData()
{
    PSEventController::subscribe(this,"capture");
    PSEventController::subscribe(this,"adjustImage");
    PSEventController::subscribe(this,"fixImage");

    connect(this,&CameraWidget::capture,this,[&](QImage image){
       graphWidget->setBackgroundImage(QPixmap::fromImage(image),true);
    },Qt::UniqueConnection);
}

void CameraWidget::on_psEvent_capture(bool isChecked)
{
    if(!isChecked){
        QPixmap backgroundImage;
        graphWidget->setBackgroundImage(backgroundImage,false);
    }else{
        isCapture=true;
    }
}

void CameraWidget::on_psEvent_adjustImage(bool isChecked)
{
    graphWidget->setIsScale(true);
}

void CameraWidget::on_psEvent_fixImage(bool isChecked)
{
    graphWidget->setIsScale(false);
}

void CameraWidget::updatePos(int x, int y)
{
    graphWidget->move(x,y);
}

bool CameraWidget::printDeviceInfo(MV_CC_DEVICE_INFO *pstMVDevInfo)
{
    if (NULL == pstMVDevInfo)
    {
        printf("The Pointer of pstMVDevInfo is NULL!\n");
        return false;
    }
    if (pstMVDevInfo->nTLayerType == MV_GIGE_DEVICE)
    {
        int nIp1 = ((pstMVDevInfo->SpecialInfo.stGigEInfo.nCurrentIp & 0xff000000) >> 24);
        int nIp2 = ((pstMVDevInfo->SpecialInfo.stGigEInfo.nCurrentIp & 0x00ff0000) >> 16);
        int nIp3 = ((pstMVDevInfo->SpecialInfo.stGigEInfo.nCurrentIp & 0x0000ff00) >> 8);
        int nIp4 = (pstMVDevInfo->SpecialInfo.stGigEInfo.nCurrentIp & 0x000000ff);

        // ch:打印当前相机ip和用户自定义名字 | en:print current ip and user defined name
        printf("CurrentIp: %d.%d.%d.%d\n" , nIp1, nIp2, nIp3, nIp4);
        printf("UserDefinedName: %s\n\n" , pstMVDevInfo->SpecialInfo.stGigEInfo.chUserDefinedName);
    }
    else if (pstMVDevInfo->nTLayerType == MV_USB_DEVICE)
    {
        printf("UserDefinedName: %s\n", pstMVDevInfo->SpecialInfo.stUsb3VInfo.chUserDefinedName);
        printf("Serial Number: %s\n", pstMVDevInfo->SpecialInfo.stUsb3VInfo.chSerialNumber);
        printf("Device Number: %d\n\n", pstMVDevInfo->SpecialInfo.stUsb3VInfo.nDeviceNumber);
    }
    else
    {
        printf("Not support.\n");
    }

    return true;
}

//std::once_flag flag;
void CameraWidget::getImage()
{
    int nRet = MV_OK;
    MV_FRAME_OUT stImageInfo = {0};
    MV_DISPLAY_FRAME_INFO stDisplayInfo = {0};

    while(1)
    {
        nRet = MV_CC_GetImageBuffer(handle, &stImageInfo, 1000);
        if (nRet == MV_OK)
        {
            // printf("Get Image Buffer: Width[%d], Height[%d], FrameNum[%d]\n",
            //  stImageInfo.stFrameInfo.nWidth, stImageInfo.stFrameInfo.nHeight, stImageInfo.stFrameInfo.nFrameNum);

            if (hwnd)
            {
                stDisplayInfo.hWnd = hwnd;
                stDisplayInfo.pData = stImageInfo.pBufAddr;
                stDisplayInfo.nDataLen = stImageInfo.stFrameInfo.nFrameLen;
                stDisplayInfo.nWidth = stImageInfo.stFrameInfo.nWidth;
                stDisplayInfo.nHeight = stImageInfo.stFrameInfo.nHeight;
                stDisplayInfo.enPixelType = stImageInfo.stFrameInfo.enPixelType;

                //转qt QImage 给到绘图窗口
                if(isCapture){
                    mvToQImage(stDisplayInfo);
                }


                //调整窗口尺寸
                //                std::call_once(flag, [&](){
                //                    int cW = stImageInfo.stFrameInfo.nWidth;
                //                    int cH = stImageInfo.stFrameInfo.nHeight;
                //                });

                MV_CC_DisplayOneFrame(handle, &stDisplayInfo);
            }

            nRet = MV_CC_FreeImageBuffer(handle, &stImageInfo);
            if(nRet != MV_OK)
            {
                printf("Free Image Buffer fail! nRet [0x%x]\n", nRet);
            }
        }
        else
        {
            printf("Get Image fail! nRet [0x%x]\n", nRet);
        }
        if(bExit)
        {
            break;
        }
    }
}

void CameraWidget::mvToQImage(MV_DISPLAY_FRAME_INFO &stDisplayInfo)
{
    QImage image;
    if(stDisplayInfo.enPixelType==PixelType_Gvsp_Mono8){
        image= QImage(stDisplayInfo.pData, stDisplayInfo.nWidth, stDisplayInfo.nHeight, QImage::Format_Indexed8);
    }else if(stDisplayInfo.enPixelType==PixelType_Gvsp_RGB8_Packed){
        image= QImage(stDisplayInfo.pData, stDisplayInfo.nWidth, stDisplayInfo.nHeight, QImage::Format_RGB888);
    }
    emit capture(image);
    isCapture=false;
}

上层绘图窗口代码：

#ifndef CAMERAWIDGET_H
#define CAMERAWIDGET_H

#include <QWidget>
#include <windows.h>
#include <MvCameraControl.h>

#include "./util/PSEventController.h"
#include "graphwidget.h"
class CameraWidget : public QWidget
{
    Q_OBJECT
public:
    explicit CameraWidget(QWidget *parent = nullptr);
    ~CameraWidget();

    void updatePos(int x,int y);

private:
    bool findDevice();
    bool printDeviceInfo(MV_CC_DEVICE_INFO* pstMVDevInfo);
    void getImage();
    bool openDevice();
    bool closeDevice();

private:
    int nRet = MV_OK;
    void* handle = NULL;
    MV_CC_DEVICE_INFO_LIST stDeviceList = {0};
    std::atomic_bool bExit = true;
    HWND hwnd = NULL;

    GraphWidget * graphWidget=nullptr;
    QWidget *videoWidget =nullptr;

    std::atomic_bool isCapture{false};

private:
    void initData();
    void mvToQImage(MV_DISPLAY_FRAME_INFO &stDisplayInfo);

public slots:
    void on_psEvent_capture(bool isChecked);
    void on_psEvent_adjustImage(bool isChecked);
    void on_psEvent_fixImage(bool isChecked);

signals:
    void capture(QImage image);
};

#endif // CAMERAWIDGET_H

#include "graphwidget.h"
#include <QGridLayout>
#include <QPainter>
#include <QMouseEvent>
#include <QDebug>

#include "../graphics/bqgraphicsitem.h"

#define VIEW_CENTER viewport()->rect().center()
#define VIEW_WIDTH  viewport()->rect().width()
#define VIEW_HEIGHT viewport()->rect().height()

GraphWidget::GraphWidget(QWidget *parent)
    : QGraphicsView{parent}
{
    setAttribute(Qt::WA_TranslucentBackground);
    setStyleSheet("background: transparent;border:0px");
    setWindowFlags(Qt::FramelessWindowHint);
    setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    setRenderHint(QPainter::Antialiasing);
    scene = new QGraphicsScene(this);
    this->setScene(scene);
    setDragMode(ScrollHandDrag);
    this->setSceneRect(this->geometry());
    centerOn(0, 0);

    initData();
}

void GraphWidget::setIsScale(bool newIsScale)
{
    isScale = newIsScale;
    if(!isScale){
        revertSize();
    }
}

void GraphWidget::setBackgroundImage(const QPixmap &newBackgroundImage,bool newIsSetBackground)
{
    qDebug()<<"setBackgroundImage "<<newIsSetBackground;
    isSetBackground=newIsSetBackground;
    if(backgroundItem){
        scene->removeItem(backgroundItem);
        backgroundItem=nullptr;
    }

    if(isSetBackground){
        setAttribute(Qt::WA_TranslucentBackground,false);
        backgroundImage = newBackgroundImage;
        if(!backgroundImage.isNull()){
            backgroundItem = scene->addPixmap(backgroundImage);
            backgroundItem->setPos(-this->width()/2,-this->height()/2);
            backgroundItem->setZValue(-1000);

            backgroundItem->setFlags(QGraphicsItem::ItemIsSelectable |
                               QGraphicsItem::ItemIsMovable |
                               QGraphicsItem::ItemIsFocusable);
            update();
        }
    }else{
        setAttribute(Qt::WA_TranslucentBackground,true);
        revertSize();
    }

}

void GraphWidget::clearItem()
{
    for(int i=0;i<scene->items().size();i++){
        QGraphicsItem *item = scene->items().at(i);
        if(item->zValue()==-1000){
            continue;
        }else{
            scene->removeItem(scene->items().at(i));
        }
    }
}

void GraphWidget::on_psEvent_addLine(bool isChecked)
{
    clearItem();
    BRectangle *m_rectangle = new BRectangle(0, 0, 100, 50, BGraphicsItem::ItemType::Rectangle);
    scene->addItem(m_rectangle);
}

void GraphWidget::on_psEvent_addCircle(bool isChecked)
{
    clearItem();
    BConcentricCircle *m_conCircle = new BConcentricCircle(0, 0, 50, 80, BGraphicsItem::ItemType::Concentric_Circle);
    scene->addItem(m_conCircle);
}

void GraphWidget::on_psEvent_addEllipse(bool isChecked)
{
    clearItem();
    BEllipse *m_ellipse = new BEllipse(0, 0, 100, 50, BGraphicsItem::ItemType::Ellipse);
    scene->addItem(m_ellipse);
}

void GraphWidget::on_psEvent_addArc(bool isChecked)
{
    clearItem();
    BPie *m_pie = new BPie(0, 0, 80, 30, BGraphicsItem::ItemType::Pie);
    scene->addItem(m_pie);
}

void GraphWidget::wheelEvent(QWheelEvent *event)
{
    if(isScale){
        static float scale = 1.1;
        auto angle = event->angleDelta();

        if(angle.y() > 0)
        {
            this->scale(scale, scale);
        }
        else
        {
            this->scale(1/scale, 1/scale);
        }
    }
}

void GraphWidget::initData()
{
    PSEventController::subscribe(this,"addLine");
    PSEventController::subscribe(this,"addCircle");
    PSEventController::subscribe(this,"addEllipse");
    PSEventController::subscribe(this,"addArc");
}

void GraphWidget::revertSize()
{
    setTransformationAnchor(QGraphicsView::AnchorViewCenter);
    QMatrix q;
    q.setMatrix(1,this->matrix().m12(),this->matrix().m21(),1,this->matrix().dx(),this->matrix().dy());
    setMatrix(q,false);
}

主窗口移动和缩放时更新视频窗口位置：

void MainWindow::updateGraphWidgetPos()
{
    if(cameraWidget){
        QPoint p =  mapToGlobal(cameraWidget->parentWidget()->pos());
        cameraWidget->updatePos(p.x(),p.y()+22);
    }
}

void MainWindow::resizeEvent(QResizeEvent *e)
{
    updateGraphWidgetPos();
    return QWidget::resizeEvent(e);
}

void MainWindow::moveEvent(QMoveEvent *e)
{
    updateGraphWidgetPos();
    return QWidget::moveEvent(e);
}