Multi-thread video capture and playback in QT Linux v4l2

I. Build a QT Project

2. Draw a display window

3. Add a program (because the v4l2 program is too long to be posted, please download it to the resource)

1. Working thread code

video_thread::video_thread():QThread() { quit_flag = false; } video_thread::~video_thread() { this->quit(); quit_flag = true; this->wait(); } void video_thread::run() { M_video.init_video (); // enable the video device. while(!quit_flag) { M_video.get_data (); // get video data unsigned char *rgb; RGB = new unsigned char [m_video.buf.length * 2]; // allocate RGB based on the ratio of the yuyv pixel to the station memory of the RGB Pixel M_video.yuvtorgbo (RGB, 640,480); // convert yuyv to RGB QImage img = QImage(rgb,640,480,QImage::Format_RGB888); emit image_data(img); msleep(150); Delete [] RGB; // It cannot be released before sleep. Otherwise, the displayed image may have problems. } M_video.release_video (); // release the device before the thread is released. }

2. Main thread Program

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) { ui->setupUi(this); connect(ui->show_ptn,SIGNAL(clicked()),this,SLOT(start_thread())); connect(ui->stop_ptn,SIGNAL(clicked()),this,SLOT(stop_thread())); connect(ui->quit_ptn,SIGNAL(clicked()),this,SLOT(close())); } void MainWindow::start_thread() { video = new video_thread(); video->start(); connect(video,SIGNAL(image_data(const QImage &)),this,SLOT(show_picture(const QImage &))); } void MainWindow::show_picture(const QImage &img) { ui->show_label->setPixmap(QPixmap::fromImage(img)); } void MainWindow::stop_thread() { delete video; } MainWindow::~MainWindow() { delete ui; }

3. Program

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