videowidget.cpp

Linux下的USB摄像头拍照程序

#define _cplusplus
#include "videowidget.h"
#include <QTime>
VideoWidget::VideoWidget(QWidget *parent)
: QWidget(parent)
{
    v4l_open(DEFAULT_DEVICE, &v4l_dev) ;/*打开设备*/
    v4l_get_capability(&v4l_dev);
    v4l_get_picture(&v4l_dev);
    v4l_init_mbuf(&v4l_dev);/*初始化设备*/
    v4l_get_mbuf(&v4l_dev);/*内存映射*/
    v4l_get_window(&v4l_dev);

    imgLabel = new QLabel(this);
    imgLabel->setGeometry(10,15,220,176);
    imgLabel->setScaledContents(true);
    

    infoLabel = new QLabel(this);
    infoLabel->setGeometry(10,2,220,10);
    infoLabel->setText(QString::number(v4l_dev.window.width)+"x"+QString::number(v4l_dev.window.height));


    img = new QImage(MAX_WIDTH,MAX_HEIGHT,QImage::Format_RGB888);

    exitButton = new QPushButton(tr("Quit"),this);
    connect(exitButton, SIGNAL(clicked()),
            qApp,SLOT(quit()));
    exitButton->setGeometry(20,240,50,30);

    saveButton = new QPushButton(tr("Save"),this);
    connect(saveButton,SIGNAL(clicked()),
            this,SLOT(sl_saveImage()));
    saveButton->setGeometry(170,240,50,30);


    
    timer = new QTimer(this);
    connect(timer, SIGNAL(timeout()), this, SLOT(sl_start()));
    timer->start(100);


#ifdef X86
    resize(240,320);
#endif
}

VideoWidget::~VideoWidget()
{
}



void VideoWidget::sl_start()
{
    int i=0;
    QRgb point;
    int r, g, b;

    v4l_grab_movie(&v4l_dev);
    qApp->processEvents();
    if (v4l_dev.picture.depth == 12)
    {
        uchar *YUVin  = v4l_dev.buffer;    
        v4l_yuv420p2rgb(RGBout, YUVin, MAX_WIDTH, MAX_HEIGHT,24);
        for(int y=0; y<MAX_HEIGHT; y++)
        {
            for(int x=0; x<MAX_WIDTH; x++)
            {
                
                r = (int)RGBout[i+2];
                g = (int)RGBout[i+1];
                b = (int)RGBout[i];
                
                point = qRgb(r,g,b);
                img->setPixel(x,y,point);
                i+=3;
                
            }
        }
    }
    else
    {
        for(int y=0; y<MAX_HEIGHT; y++)
        {
            for(int x=0; x<MAX_WIDTH; x++)
            {
                
                r = (int)v4l_dev.buffer[i+2];
                g = (int)v4l_dev.buffer[i+1];
                b = (int)v4l_dev.buffer[i];
                
                point = qRgb(r,g,b);
                img->setPixel(x,y,point);
                i+=3;
                
            }
        }
    }
    

    

    imgLabel->setPixmap(QPixmap::fromImage(*img));

}

void VideoWidget::closeEvent(QCloseEvent *event)
{   
    if(timer->timerId())
    {
        killTimer(timer->timerId());
    }
    v4l_munmap(&v4l_dev) ;
    v4l_close(&v4l_dev); 
    event->accept();
 }

void VideoWidget::sl_saveImage()
{
    QTime time;
    timer->stop();
    img->save(".tmp.bmp","BMP");
    QImage image;
    image.load(".tmp.bmp");
    image.save(QString("image-%1%2%3.jpg")
               .arg(time.currentTime().hour())
               .arg(time.currentTime().minute())
               .arg(time.currentTime().second())
               ,"JPEG");
    int endTime = QTime::currentTime().second();

    imgLabel->setText("saving...");
    imgLabel->setAlignment(Qt::AlignCenter);
    timer->start();

}