用QT写的usb摄像头播放器，可以用于linux平台和Windows平台 因为QT配置不同在不同平台下都可以编译，希望对你有所帮...

#include "dialog.h" #include "ui_dialog.h" #include <QString> #include <string> #include <QMessageBox> Dialog::Dialog(QWidget *parent) : QDialog(parent) , ui(new Ui::Dialog) { ui->setupUi(this); m_timer = new QTimer(this); ui->Exposure->setText("-5"); connect(m_timer, SIGNAL(timeout()), this, SLOT(readFrame())); } Dialog::~Dialog() { if(m_timer != nullptr) { m_timer->stop(); } delete ui; } void Dialog::on_btn_Rec_clicked() { cap.open(0); double frame_width = cap.get(CAP_PROP_FRAME_WIDTH); double frame_height = cap.get(CAP_PROP_FRAME_HEIGHT); double frame_rate = cap.get(CAP_PROP_FPS); printf("frame_width: %f, frame_height: %f, frame_rate: %f.\n", frame_width, frame_height, frame_rate); cap.set(CAP_PROP_FOURCC, cv::VideoWriter::fourcc('M', 'J', 'P', 'G')); cap.set(CAP_PROP_FPS,25); cap.set(CAP_PROP_FRAME_WIDTH, 640); cap.set(CAP_PROP_FRAME_HEIGHT, 480); double frame_set_width = cap.get(cv::CAP_PROP_FRAME_WIDTH); double frame_set_height = cap.get(cv::CAP_PROP_FRAME_HEIGHT); double frame_set_rate = cap.get(cv::CAP_PROP_FPS); printf("frame_set_width: %f, frame_set_height: %f, frame_set_rate: %f.\n", frame_set_width, frame_set_height, frame_set_rate); if (!cap.isOpened()) { printf("open camera err.\n"); return; } if(ui->AutoExposure->isChecked()) { QMessageBox::about(this, "info", "checked"); double getAuto = cap.get(cv::CAP_PROP_AUTO_EXPOSURE); qDebug() << "GET_AUTO_EXPOSURE" << getAuto; cap.set(cv::CAP_PROP_AUTO_EXPOSURE, -1); } else { QMessageBox::about(this, "info", "No checked"); //手动曝光设置代码片段 int getEx = cap.get(cv::CAP_PROP_EXPOSURE); qDebug() << "GET_EXPOSURE_START" << getEx; //先设置自动为0.25 cap.set(cv::CAP_PROP_AUTO_EXPOSURE, 0.25); //取值范围是：-13 ~ -1 int exp = ui->Exposure->text().toInt(); cap.set(cv::CAP_PROP_EXPOSURE, exp); qDebug() << "SET_EXPOSURE" << exp; double getEx2 = cap.get(cv::CAP_PROP_EXPOSURE); qDebug() << "GET_EXPOSURE" << getEx2; } Size videoSize(640, 480); //int fourcc = cv::VideoWriter::fourcc('M', 'J', 'P', 'G'); int fourcc = cv::VideoWriter::fourcc('X', 'V', 'I', 'D'); writer.open("R640.avi", fourcc, 25, videoSize); if (!writer.isOpened()) { //printf("open file err.\n"); qDebug()<< "open file err"; return; } m_timer->start(40); } void Dialog::on_btn_Stop_clicked() { cap.release(); writer.release(); m_timer->stop(); } void Dialog::readFrame() { Mat frame; QElapsedTimer timer; timer.start(); cap.read(frame); frame.type(); //writer.write(frame); int milsec = timer.elapsed(); qDebug() << "rec need" << milsec << "ms"; Mat zoomImg(cv::Size(800, 450), CV_8UC3, cv::Scalar(255,255,255)); cvtColor(frame, zoomImg, COLOR_BGR2RGB); QImage::Format format; switch (zoomImg.type()) { case CV_8UC1: format = QImage::Format_Indexed8; break; case CV_8UC3: format = QImage::Format_RGB888; break; case CV_8UC4: format = QImage::Format_ARGB32; break; } QImage img = QImage((const uchar*)zoomImg.data, zoomImg.cols, zoomImg.rows, format); ui->videoDisplay->clear(); QPixmap pixmap = QPixmap::fromImage(img); pixmap = pixmap.scaled(ui->videoDisplay->size()); ui->videoDisplay->setAutoFillBackground(true); QPalette palette; palette.setBrush(ui->videoDisplay->backgroundRole(), QBrush(pixmap)); ui->videoDisplay->setPalette(palette); ui->videoDisplay->repaint(); }