video1.cpp~

一个摄像头的显示程序

#include <qapplication.h> 
#include <qpushbutton.h> 
#include <qwidget.h> 
#include <qcolor.h> 
#include <qtimer.h> 
#include <qframe.h> 
#include <math.h> 
#include <qimage.h> 
#include <qpainter.h> 
 
#include <stdio.h> 
#include <stdlib.h> 
#include <unistd.h> 
#include <linux/videodev.h> 
#include <sys/ioctl.h> 
#include <fcntl.h> 
#include <linux/fb.h> 
#include <sys/mman.h> 
#include <string.h> 
 
#define ERR_FRAME_BUFFER 1 
#define ERR_VIDEO_OPEN  2 
#define ERR_VIDEO_GCAP  3 
#define ERR_VIDEO_GPIC  4 
#define ERR_VIDEO_SPIC  5 
#define ERR_SYNC    6 
#define ERR_FRAME_USING  7 
#define ERR_GET_FRAME    8 
#define RIGHT_GRAP_FRAME 9
#define RIGHT_OPEN_VIDEO 10
int screensize; 
#define V4L_FILE "/dev/video0"  
#define DEFAULT_PALETTE VIDEO_PALETTE_RGB565 
 
 
 
class MyWidget : public QWidget 
{ 
//O_OBJECT 
public: 
    MyWidget( QWidget *parent=0, const char *name=0 ); 
    int open_video();     
    int get_grab_frame(); 
    void paintEvent(QPaintEvent *); 
private: 
    QTimer *timer; 
    QFrame *frame; 
    unsigned short imageptr; 
    int dep; 
    int pal; 
    int width; 
    int height; 
    // FrameBuffer 信息 
    struct fb_var_screeninfo vinfo;  // FrameBuffer屏幕可变的信息 
    struct fb_fix_screeninfo finfo;  // FrameBuffer固定不变的信息 
    //video4linux信息  
     int fd; 
    struct video_capability  capability;  
    struct video_buffer  buffer;   
    struct video_picture  picture;   
    struct video_mmap  map;     
    struct video_mbuf  mbuf;          
    unsigned char  *pmap; 
    int frame_current;//what 's the frame number being captured currently? 
    int frame_using[VIDEO_MAX_FRAME];//帧的状态没有采集还是等待结束? 
    int screensize; 
 
}; 
 
MyWidget::MyWidget( QWidget *parent, const char *name ) 
        : QWidget( parent, name ) 
{   O_OBJECT;
  dep=16; 
  pal=VIDEO_PALETTE_RGB565; 
  width=320; 
  height=240; 
 
  frame_current = 0; 
  frame_using[0] = 0; 
  frame_using[1] = 0; 
   
  setCaption("Video"); 
  frame=new QFrame(this,"frame"); 
  frame->setBackgroundColor(black); 
  frame->setGeometry(QRect(40,40,402,252)); 
  QTimer *timer=new QTimer(this,"timer"); 
  timer = new QTimer(this); 
  connect(timer, SIGNAL(timeout()), SLOT(update())); 
  timer->start(30);  
  printf("timer is using\n"); 
 
} 
 
int MyWidget::get_grab_frame() 
{ 
   
  if (frame_using[frame_current]) { 
      fprintf(stderr, "get_grab_frame: frame %d is already used.\n", frame_current); 
      return ERR_FRAME_USING; 
  } 
 
  map.frame = frame_current; 
  
  if (ioctl(fd, VIDIOCMCAPTURE, &(map)) < 0) { 
      perror("v4l_grab_frame"); 
      return ERR_GET_FRAME; 
  } 
  //置为采集忙状态 
  frame_using[frame_current] = 1; 
   
  if (ioctl(fd, VIDIOCSYNC, &(frame_current)) < 0) // 等待帧同步 
  {   
      perror("v4l_grab_sync"); 
      return ERR_SYNC; 
  } 
  frame_using[frame_current] = 0 ;//采集完毕置0 
  return RIGHT_GRAP_FRAME; 
 
} 
int MyWidget::open_video() 
{ 
  // 打开视频设备 
      if ((fd = open(V4L_FILE, O_RDWR)) < 0) 
  { 
      perror("v4l_open:"); 
      return ERR_VIDEO_OPEN; 
  } 
    printf("=============Open Video Success======================="); 
     
  // 获取设备 
  if (ioctl(fd, VIDIOCGCAP, &(capability)) < 0) 
  { 
      perror("v4l_get_capability:"); 
      return ERR_VIDEO_GCAP; 
  } 
  printf("Camera found: %s,maxwidth:%d,maxheight:%d,minwidth:%d,minheight:%d \n",capability.name,capability.maxwidth,capability.maxheight,capability.minwidth,capability.minheight); 
 
  printf("=============Get Device Success======================="); 
  // 获取图象  
  if (ioctl(fd, VIDIOCGPICT, &(picture)) < 0) 
  { 
      perror("v4l_get_picture"); 
      return ERR_VIDEO_GPIC; 
  } 
      printf("=============Get Picture Success======================="); 
     printf("=====Capture depth:%d,Palette:%d,brightness:%d,hue:%d,contrast:%d===============\n",picture.depth,picture.palette,picture.brightness,picture.hue,picture.contrast); 
  // 设置图象 
  picture.palette = pal;  // 调色板 
  picture.depth = dep;  // 像素深度 
 
  map.format =pal; 
  if (ioctl(fd, VIDIOCSPICT, &(picture)) < 0) 
  { 
      perror("v4l_set_palette"); 
      return ERR_VIDEO_SPIC; 
  } 
  printf("=====Capture depth:%d,Palette:%d,brightness:%d,hue:%d,contrast:%d===============\n",picture.depth,picture.palette,picture.brightness,picture.hue,picture.contrast); 
   
  memset (&(mbuf), 0, sizeof(mbuf)); 
  // 获取摄像头缓冲区信息 
  if (ioctl(fd, VIDIOCGMBUF, &(mbuf)) < 0) 
  { 
      perror("v4l_get_mbuf"); 
      return -1; 
  } 
  printf ("VIDIOCGMBUF size %d  frames %d  offets[0]=%d offsets[1]=%d\n",mbuf.size, mbuf.frames, mbuf.offsets[0], mbuf.offsets[1]); 
  // 建立设备内存影射,将视频设备影射到内存空间  
  pmap = (unsigned char *) (mmap(NULL, mbuf.size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)); 
  if ( pmap < 0) 
  { 
      perror("v4l_mmap_init:map"); 
      return -1; 
  } 
  map.width = width;  // width; 
  map.height = height;  // height; 
  map.format = picture.palette; 
  printf("The video device was opened successfully.\n"); 
  return RIGHT_OPEN_VIDEO;
} 
 

void MyWidget::paintEvent(QPaintEvent *) 
{ 
    int x, y; 
    int i = 0; 
    QRgb *point; 
    int r, g, b; 
    int imgwidth=402; 
    int imgheight=252; 
    //创建该PaintEvent的操作对象paint 
        //该对象为静态对象，不需要每次paint都创建一个QPainter 
    static QPainter paint(frame); 
         //读取内存内容，创建QImage对象 
    QImage *image = new QImage(); 
 
    //该步很重要，设置标志 
    //让QWidget在更新窗体时，不擦除原来的窗体 
    //这样可以避免闪屏 
    setWFlags(getWFlags() | Qt::WRepaintNoErase); 
     
    //begin graping picture 
    get_grab_frame(); 
    imageptr = (unsigned short) ( pmap + mbuf.offsets[frame_current]); 
    
    frame_current ^= 1;//两帧采集不是0就是1 
 
    if(image->create(imgwidth, imgheight, 32, 0, QImage::IgnoreEndian)) 
    { 
        for(x = 0; x < imgheight; x++) 
        { 
            for(y = 0; y < imgwidth; y++) 
            { 
                r =(imageptr&0xf800)>>11; 
                g = (imageptr&0x07e0)>>5; 
                b = imageptr&0x001f; 
                point = (QRgb *)image->scanLine(x)+y; 
                *point = qRgb(r, g, b); 
                i++; 
                 
            } 
        } 
    } 
 
    //开始绘图   
    paint.drawImage(0, 0, *image); 
   // paint.drawImage(QRect(40,34,402,252), *image); 
    
} 
 
int main( int argc, char **argv ) 
{ 
    QApplication a( argc, argv ); 
 
    MyWidget *w=new MyWidget(0); 
    w->setGeometry( 10, 20, 480, 320 ); 
    a.setMainWidget( w ); 
    w->show(); 
    w->open_video();  
    //a.connect( &a, SIGNAL( lastWindowClosed() ), &a, SLOT( quit() ) ); 
    return a.exec(); 
}