我在做基于qt下显示摄像头获取的信息，就是显示不出来，大家看看我错在哪个地方啊 ？
#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
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 );
//unsigned char* get_image();
//void get_image();
int open_video();
int get_grab_frame();
//void paintEvent(QPaintEvent *);
//protected:
//virtual void paintEvent(QPaintEvent *);
void paintEvent(QPaintEvent *);
private:
QTimer *timer;
QFrame *frame;
//unsigned short* imageptr;
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 short *pmap;
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 )
{
dep=16;
pal=VIDEO_PALETTE_RGB565;
width=320;
height=240;
frame_current = 0;
frame_using[0] = 0;
frame_using[1] = 0;
setCaption("MyJob");
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);
//QTimer::singleShot(50,this,SLOT(update()));
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;
/**
Start Picture capture from this moment
*/
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);
//
/*vd->map.width = width; // width;
vd->map.height = height; // height;
vd->map.format = vd->picture.palette;*/
/*frame_current = 0;
frame_using[0] = 0;
frame_using[1] = 0;*/
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(0, 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");
}
/*void MyWidget::get_image()
{
//open_video();
imageptr = (unsigned short *)(pmap + mbuf.offsets[frame_current]);
printf("imageptr is 0x%x",imageptr);
/*err:
if(vd.fbfd)
close(vd.fbfd); // 关闭FrameBuffer设备
if(vd.fd)
close(vd.fd);
exit(0);
return 0;*/
//}*/
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]);
//printf("imageptr is 0x%x",imageptr);
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);
//printf("imageptr[0] is 0x%x",imageptr[0]);
// paint.end();
//释放空间
/* if(vd->mbuf.size)
{
munmap(imageptr,vd->mbuf.size);
}
else if(imageptr)
{
free(imageptr);
}
delete image;
image = NULL;*/
}
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();
}
