一、环境介绍
上一版本的QT+OpenCV例子在这里：https://blog.csdn.net/xiaolong1126626497/article/details/105295367
上一版的代码里，OpenCV的内存释放没有处理好，导致在处理实时视频时，长时间运行内存会持续上升，最终会因为内存不足，导致程序崩溃。
二、核心代码示例
widget.cpp文件代码：
#include "widget.h" #include "ui_widget.h" class VideoAudioEncode videoaudioencode_0; Widget::Widget(QWidget *parent) : QWidget(parent) , ui(new Ui::Widget) { ui->setupUi(this); //驾驶室摄像头 //工作对象 videoRead_WorkClass_0=new VideoReadThread_0; videoRead_Workthread_0=new QThread; //连接摄像头采集信号,在主线程实时显示视频画面 connect(videoRead_WorkClass_0,SIGNAL(VideoDataOutput(QImage )),this,SLOT(VideoDataDisplay_0(QImage ))); //摄像头初始化函数 connect(this,SIGNAL(Init_VideoAudio_WorkClass_0()),videoRead_WorkClass_0,SLOT(run())); //停止视频采集 connect(this,SIGNAL(Stop_AudioVideo0_work_0()),videoRead_WorkClass_0,SLOT(stop())); //将工作对象移动到子线程里工作 videoRead_WorkClass_0->moveToThread(videoRead_Workthread_0); //更新设备列表 UpdateVideoAudiodDevice(ui->comboBox_video_0,ui->plainTextEdit_log_0); // timer.start(100); connect(&timer,SIGNAL(timeout()), this, SLOT(update())); timer.start(100); } Widget::~Widget() { delete ui; } //分类器的路径 //人眼检测 //#define eye_source_xml_addr "C:/OpenCV_2.4/opencv/sources/data/haarcascades_GPU/haarcascade_eye.xml" //人脸检测 #define face_source_xml_addr "C:/OpenCV_2.4/opencv/sources/data/haarcascades_GPU/haarcascade_frontalface_alt2.xml" //嘴巴检测 //#define source_xml_addr "D:/linux-share-dir/samples/cascade3.xml" //人脸检测代码 void Widget::opencv_face(QImage qImage) { QTime time; time.start(); static CvMemStorage* storage = nullptr; static CvHaarClassifierCascade* cascade = nullptr; //加载分类器：正面脸检测 cascade = (CvHaarClassifierCascade*)cvLoad(face_source_xml_addr, 0, 0, 0 ); if(!cascade) { Log_Display_0("分类器加载错误.\n"); return ; } //创建内存空间 storage = cvCreateMemStorage(0); //加载需要检测的图片 IplImage* img = QImageToIplImage(&qImage); if(img ==nullptr ) { Log_Display_0("图片加载错误.\n"); return; } double scale=1.2; //标记人脸框的颜色 static CvScalar colors[] = { {{0,0,255}},{{0,128,255}},{{0,255,255}},{{0,255,0}}, {{255,128,0}},{{255,255,0}},{{255,0,0}},{{255,0,255}} }; //创建图像首地址，并分配存储空间 IplImage* gray = cvCreateImage(cvSize(img->width,img->height),8,1); //创建图像首地址，并分配存储空间 IplImage* small_img=cvCreateImage(cvSize(cvRound(img->width/scale),cvRound(img->height/scale)),8,1); cvCvtColor(img,gray, CV_BGR2GRAY); cvResize(gray, small_img, CV_INTER_LINEAR); cvEqualizeHist(small_img,small_img); //直方图均衡 /* * 指定相应的人脸特征检测分类器，就可以检测出图片中所有的人脸，并将检测到的人脸通过矩形的方式返回。 * 总共有8个参数，函数说明： 参数1：表示输入图像，尽量使用灰度图以加快检测速度。 参数2：表示Haar特征分类器，可以用cvLoad()函数来从磁盘中加载xml文件作为Haar特征分类器。 参数3：用来存储检测到的候选目标的内存缓存区域。 参数4：表示在前后两次相继的扫描中，搜索窗口的比例系数。默认为1.1即每次搜索窗口依次扩大10% 参数5：表示构成检测目标的相邻矩形的最小个数(默认为3个)。如果组成检测目标的小矩形的个数和小于 min_neighbors - 1 都会被排除。如果min_neighbors 为 0, 则函数不做任何操作就返回所有的被检候选矩形框，这种设定值一般用在用户自定义对检测结果的组合程序上。 参数6：要么使用默认值，要么使用CV_HAAR_DO_CANNY_PRUNING，如果设置为CV_HAAR_DO_CANNY_PRUNING，那么函数将会使用Canny边缘检测来排除边缘过多或过少的区域，因此这些区域通常不会是人脸所在区域。 参数7：表示检测窗口的最小值，一般设置为默认即可。 参数8：表示检测窗口的最大值，一般设置为默认即可。 函数返回值：函数将返回CvSeq对象，该对象包含一系列CvRect表示检测到的人脸矩形。 */ CvSeq* objects = cvHaarDetectObjects(small_img, cascade, storage, 1.1, 3, 0/*CV_HAAR_DO_CANNY_PRUNING*/, cvSize(50,50)/*大小决定了检测时消耗的时间多少*/); //qDebug()<<"人脸数量:"<<objects->total; ui->lcdNumber->display(objects->total); //显示检测的人脸数量 //遍历找到对象和周围画盒 for(int i=0;i<(objects->total);++i) { //得到人脸的坐标位置和宽度高度信息 CvRect* r=(CvRect*)cvGetSeqElem(objects,i); //将人脸区域绘制矩形圈起来 cvRectangle(img, cvPoint(r->x*scale,r->y*scale), cvPoint((r->x+r->width)*scale,(r->y+r->height)*scale), colors[i%8]); } //将人脸区域矩形内再绘制圆圈起来 for( int i = 0; i < (objects? objects->total : 0); i++ ) { CvRect* r = (CvRect*)cvGetSeqElem( objects,i); CvPoint center; int radius; center.x = cvRound((r->x + r->width*0.5)*scale); center.y = cvRound((r->y + r->height*0.5)*scale); radius = cvRound((r->width + r->height)*0.25*scale); cvCircle(img, center, radius, colors[i%8], 3, 8, 0 ); } show_face(img); //显示检测的结果 cvReleaseImage(&gray); //释放图片内存 cvReleaseImage(&small_img); //释放图片内存 cvReleaseHaarClassifierCascade(&cascade); //释放内存-->分类器 cvReleaseMemStorage(&objects->storage); //释放内存-->检测出图片中所有的人脸 //释放图片 cvReleaseImage(&img); Log_Display_0(tr("耗时:%1 ms\n").arg(time.elapsed())); } /*将QImage图片转为opecv的qimage格式*/ IplImage *Widget::QImageToIplImage(const QImage * qImage) { int width = qImage->width(); int height = qImage->height(); CvSize Size; Size.height = height; Size.width = width; IplImage *IplImageBuffer = cvCreateImage(Size, IPL_DEPTH_8U, 3); for (int y = 0; y < height; ++y) { for (int x = 0; x < width; ++x) { QRgb rgb = qImage->pixel(x, y); CV_IMAGE_ELEM( IplImageBuffer, uchar, y, x*3+0 ) = qBlue(rgb); CV_IMAGE_ELEM( IplImageBuffer, uchar, y, x*3+1 ) = qGreen(rgb); CV_IMAGE_ELEM( IplImageBuffer, uchar, y, x*3+2 ) = qRed(rgb); } } return IplImageBuffer; } /*将opecv的图片转为qimage格式*/ QImage *Widget::IplImageToQImage(IplImage *img) { QImage *qmg; uchar *imgData=(uchar *)img->imageData; qmg = new QImage(imgData,img->width,img->height,QImage::Format_RGB888); *qmg=qmg->rgbSwapped(); //BGR格式转RGB return qmg; } //显示检测的结果 void Widget::show_face(IplImage* img) { uchar *imgData=(uchar *)img->imageData; QImage my_image=QImage(imgData,img->width,img->height,QImage::Format_RGB888); my_image=my_image.rgbSwapped(); //BGR格式转RGB QPixmap my_pix; //创建画图类 my_pix.convertFromImage(my_image); /*在控件上显示*/ ui->label_display->setPixmap(my_pix); } //开始采集 void Widget::on_pushButton_Start_clicked() { //设置当前选择的摄像头 videoaudioencode_0.camera=video_dev_list.at(ui->comboBox_video_0->currentIndex()); Stop_VideoAudioEncode_0(true); Start_VideoAudioEncode_Thread_0(); } //析构函数 VideoReadThread_0::~VideoReadThread_0() { } //停止视频采集 void VideoReadThread_0::stop() { qDebug()<<"停止视频采集--stop"; if(camera) { camera->stop(); delete camera; camera=nullptr; } if(m_pProbe) { delete m_pProbe; m_pProbe=nullptr; } } //执行线程 void VideoReadThread_0::run() { stop(); Camear_Init(); qDebug()<<"摄像头开始采集数据"; } void VideoReadThread_0::Camear_Init() { /*创建摄像头对象，根据选择的摄像头打开*/ camera = new QCamera(videoaudioencode_0.camera); m_pProbe = new QVideoProbe; if(m_pProbe != nullptr) { m_pProbe->setSource(camera); // Returns true, hopefully. connect(m_pProbe, SIGNAL(videoFrameProbed(QVideoFrame)),this, SLOT(slotOnProbeFrame(QVideoFrame)), Qt::QueuedConnection); } /*配置摄像头捕 QCamera *camera; QVideoProbe *m_pProbe;获模式为帧捕获模式*/ //camera->setCaptureMode(QCamera::CaptureStillImage); //如果在Linux系统下运行就这样设置 camera->setCaptureMode(QCamera::CaptureVideo);//如果在android系统下运行就这样设置 /*启动摄像头*/ camera->start(); /*设置摄像头的采集帧率和分辨率*/ QCameraViewfinderSettings settings; settings.setPixelFormat(QVideoFrame::Format_YUYV); //设置像素格式 Android上只支持NV21格式 settings.setResolution(QSize(VIDEO_WIDTH,VIDEO_HEIGHT)); //设置摄像头的分辨率 camera->setViewfinderSettings(settings); } /** * NV21是android相机默认格式 * @param data * @param rgb * @param width * @param height */ void NV21_TO_RGB24(unsigned char *yuyv, unsigned char *rgb, int width, int height) { const int nv_start = width * height ; int index = 0, rgb_index = 0; uint8_t y, u, v; int r, g, b, nv_index = 0,i, j; for(i = 0; i < height; i++){ for(j = 0; j < width; j ++){ //nv_index = (rgb_index / 2 - width / 2 * ((i + 1) / 2)) * 2; nv_index = i / 2 * width + j - j % 2; y = yuyv[rgb_index]; u = yuyv[nv_start + nv_index ]; v = yuyv[nv_start + nv_index + 1]; r = y + (140 * (v-128))/100; //r g = y - (34 * (u-128))/100 - (71 * (v-128))/100; //g b = y + (177 * (u-128))/100; //b if(r > 255) r = 255; if(g > 255) g = 255; if(b > 255) b = 255; if(r < 0) r = 0; if(g < 0) g = 0; if(b < 0) b = 0; index = rgb_index % width + (height - i - 1) * width; //rgb[index * 3+0] = b; //rgb[index * 3+1] = g; //rgb[index * 3+2] = r; //颠倒图像 //rgb[height * width * 3 - i * width * 3 - 3 * j - 1] = b; //rgb[height * width * 3 - i * width * 3 - 3 * j - 2] = g; //rgb[height * width * 3 - i * width * 3 - 3 * j - 3] = r; //正面图像 rgb[i * width * 3 + 3 * j + 0] = b; rgb[i * width * 3 + 3 * j + 1] = g; rgb[i * width * 3 + 3 * j + 2] = r; rgb_index++; } } } /* 函数功能: 将YUV数据转为RGB格式 函数参数: unsigned char *yuv_buffer: YUV源数据 unsigned char *rgb_buffer: 转换之后的RGB数据 int iWidth,int iHeight : 图像的宽度和高度 */ void yuyv_to_rgb(unsigned char *yuv_buffer,unsigned char *rgb_buffer,int iWidth,int iHeight) { int x; int z=0; unsigned char *ptr = rgb_buffer; unsigned char *yuyv= yuv_buffer; for (x = 0; x < iWidth*iHeight; x++) { int r, g, b; int y, u, v; if (!z) y = yuyv[0] << 8; else y = yuyv[2] << 8; u = yuyv[1] - 128; v = yuyv[3] - 128; r = (y + (359 * v)) >> 8; g = (y - (88 * u) - (183 * v)) >> 8; b = (y + (454 * u)) >> 8; *(ptr++) = (r > 255) ? 255 : ((r < 0) ? 0 : r); *(ptr++) = (g > 255) ? 255 : ((g < 0) ? 0 : g); *(ptr++) = (b > 255) ? 255 : ((b < 0) ? 0 : b); if(z++) { z = 0; yuyv += 4; } } } void VideoReadThread_0::slotOnProbeFrame(const QVideoFrame &frame) { QVideoFrame cloneFrame(frame); cloneFrame.map(QAbstractVideoBuffer::ReadOnly); //qDebug()<<"height:"<<cloneFrame.height(); //qDebug()<<"width:"<<cloneFrame.width(); //qDebug()<<"bytesPerLine:"<<cloneFrame.bytesPerLine(); //qDebug()<<"mappedBytes:"<<cloneFrame.mappedBytes(); //qDebug()<<"pixelFormat:"<<cloneFrame.pixelFormat(); unsigned char rgb_buffer[VIDEO_WIDTH*VIDEO_HEIGHT*3]; if(cloneFrame.pixelFormat()==QVideoFrame::Format_NV21) { NV21_TO_RGB24(cloneFrame.bits(),rgb_buffer,cloneFrame.width(),cloneFrame.height()); } else if(cloneFrame.pixelFormat()==QVideoFrame::Format_YUYV) { yuyv_to_rgb(cloneFrame.bits(),rgb_buffer,cloneFrame.width(),cloneFrame.height()); } else { qDebug("当前格式编码为%1,暂时不支持转换.\n"); } cloneFrame.unmap(); //加载图片数据 QImage image(rgb_buffer, cloneFrame.width(), cloneFrame.height(), QImage::Format_RGB888); //绘制图片水印 QDateTime dateTime(QDateTime::currentDateTime()); //时间效果: 2020-03-05 16:25::04 周一 QString qStr=""; qStr+=dateTime.toString("yyyy-MM-dd hh:mm:ss ddd"); QPainter pp(&image); QPen pen = QPen(Qt::white); pp.setPen(pen); pp.drawText(QPointF(0,20),qStr); emit VideoDataOutput(image); //发送信号 } //驾驶室:视频刷新显示 void Widget::VideoDataDisplay_0(QImage image) { QPixmap my_pixmap; my_pixmap.convertFromImage(image); /*在控件上显示*/ ui->label_ImageDisplay_0->setPixmap(my_pixmap); } //驾驶室:日志显示 void Widget::Log_Display_0(QString text) { if(ui->plainTextEdit_log_0->toPlainText().size()>1000) ui->plainTextEdit_log_0->clear(); Log_Text_Display(ui->plainTextEdit_log_0,text); } /*日志显示*/ void Widget::Log_Text_Display(QPlainTextEdit *plainTextEdit_log,QString text) { plainTextEdit_log->insertPlainText(text); //移动滚动条到底部 QScrollBar *scrollbar = plainTextEdit_log->verticalScrollBar(); if(scrollbar) { scrollbar->setSliderPosition(scrollbar->maximum()); } } //驾驶室:开启所有采集线程 void Widget::Start_VideoAudioEncode_Thread_0() { videoRead_Workthread_0->start(); //开启视频采集线程 Init_VideoAudio_WorkClass_0(); //发送初始化信号 } //驾驶室:退出所有采集线程 void Widget::Stop_VideoAudioEncode_0(bool flag) { if(flag==true) { Stop_AudioVideo0_work_0(); //发送信号停止摄像头 QThread::msleep(10); //退出视频采集 videoRead_Workthread_0->quit(); //告诉线程的事件循环以return 0（成功）退出 videoRead_Workthread_0->wait(); //等待线程退出 } } void Widget::on_pushButton_update_clicked() { UpdateVideoAudiodDevice(ui->comboBox_video_0,ui->plainTextEdit_log_0); } /*刷新本机可以的音频设备列表*/ void Widget::UpdateVideoAudiodDevice( QComboBox *comboBox_video, QPlainTextEdit *plainTextEdit_log) { /*2. 获取摄像头列表*/ video_dev_list.clear(); comboBox_video->clear(); video_dev_list=QCameraInfo::availableCameras(); for(int i=0;i<video_dev_list.size();i++) { comboBox_video->addItem(video_dev_list.at(i).deviceName()); } /*如果没有可用的摄像头设备，按钮不可用*/ if(video_dev_list.size()==0) { Log_Text_Display(plainTextEdit_log,"未查询到可用的摄像头设备.\n"); } } //停止采集 void Widget::on_pushButton_stop_clicked() { Stop_VideoAudioEncode_0(true); } void Widget::update() { if(ui->label_ImageDisplay_0->pixmap()) opencv_face(ui->label_ImageDisplay_0->pixmap()->toImage()); //opencv_face_2(ui->label_ImageDisplay_0->pixmap()->toImage()); }
widget.h文件代码：
#ifndef WIDGET_H #define WIDGET_H #include <QWidget> //opencv include #include <cv.h> #include <cxcore.h> #include <highgui.h> #include <QCamera> #include <QVideoProbe> #include <QAbstractVideoSurface> #include <QVideoProbe> #include <QThread> #include <QApplication> #include <QDebug> #include <QObject> #include <QMutex> #include <QMutexLocker> #include <QWaitCondition> #include <QQueue> #include <QCamera> #include <QPen> #include <QPainter> #include <QRgb> #include <QDateTime> #include <QCameraInfo> #include <QPlainTextEdit> #include <QScrollBar> #include <QComboBox> #include <QTimer> QT_BEGIN_NAMESPACE namespace Ui { class Widget; } QT_END_NAMESPACE class Widget : public QWidget { Q_OBJECT public: Widget(QWidget *parent = nullptr); void opencv_face(QImage qImage); ~Widget(); QList<QCameraInfo> video_dev_list; void show_face(IplImage* img); class VideoReadThread_0 *videoRead_WorkClass_0; //视频工作类 QThread *videoRead_Workthread_0; //视频线程 /*驾驶室摄像头*/ void Stop_VideoAudioEncode_0(bool flag);//停止线程 void Start_VideoAudioEncode_Thread_0(); //启动线程 void Log_Text_Display(QPlainTextEdit *plainTextEdit_log,QString text); void UpdateVideoAudiodDevice(QComboBox *comboBox_video, QPlainTextEdit *plainTextEdit_log); IplImage *QImageToIplImage(const QImage * qImage); QImage *IplImageToQImage(IplImage *img); QTimer timer; signals: void Init_VideoAudio_WorkClass_0(); void Stop_AudioVideo0_work_0(); private slots: void update(); void on_pushButton_Start_clicked(); void Log_Display_0(QString text); void VideoDataDisplay_0(QImage ); void on_pushButton_update_clicked(); void on_pushButton_stop_clicked(); private: Ui::Widget *ui; }; class VideoReadThread_0:public QObject { Q_OBJECT public: QCamera *camera; QVideoProbe *m_pProbe; VideoReadThread_0(QObject* parent=nullptr):QObject(parent){camera=nullptr;m_pProbe=nullptr;} ~VideoReadThread_0(); void Camear_Init(void); public slots: void stop(); void run(); void slotOnProbeFrame(const QVideoFrame &frame); signals: void VideoDataOutput(QImage); //输出信号 }; //视频音频编码类 class VideoAudioEncode { public: QCameraInfo camera; //当前选择的摄像头 }; //视频输出尺寸 #define VIDEO_WIDTH 640 #define VIDEO_HEIGHT 480 extern class VideoAudioEncode videoaudioencode_0; #endif // WIDGET_H
Ui界面：
