main.cpp

一个在S3C2410开发板视频采集播放程序

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#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 WIDTH 640
#define HEIGHT 480
typedef struct _fb_v4l
{
    int fbfd ;            // FrameBuffer设备句柄
    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
    char *fbp;            // FrameBuffer 内存指针
  // video4linux信息  
   int fd;              
   struct video_capability  capability; 
   struct video_buffer buffer;   
   struct video_window window;  
   struct video_channel channel[8];
   struct video_picture picture;  
   struct video_tuner tuner;  
   struct video_audio audio[8];  
   struct video_mmap mmap;   
   struct video_mbuf mbuf;   
   unsigned char  *map;         
   int frame_current;
   int frame_using[VIDEO_MAX_FRAME];//帧的状态没有采集还是等待结束?
}fb_v41;
#define DEFAULT_PALETTE VIDEO_PALETTE_RGB565
#define FB_FILE "/dev/fb/0"
#define V4L_FILE "/dev/video0" 
struct video_mmap
{
unsigned int frame;             
int height,width;
unsigned int format;    
};
struct video_mbuf
{
  int size;           
  int frames;        
  int offsets[VIDEO_MAX_FRAME]; 
};
int get_grab_frame(fb_v41 *vd, int frame)
{
//如果正在采集中
   if (vd->frame_using[frame]) {
      fprintf(stderr, "get_grab_frame: frame %d is already used.\n", frame);
      return ERR_FRAME_USING;
   }
   vd->mmap.frame = frame;
   if (ioctl(vd->fd, VIDIOCMCAPTURE, &(vd->mmap)) frame_using[frame] = 1;
   vd->frame_current = frame;
   return 0;
}
int get_first_frame(fb_v41 *vd)
{
  int ret;
  
vd->frame_current = 0;
ret = get_grab_frame( vd, 0 );
if ( retfd,VIDIOCSYNC,&(vd->frame_current))frame_using[vd->frame_current] = 0 ;  
return (0);
}
int get_next_frame(fb_v41 *vd)
{
int ret;
vd->frame_current ^= 1;//两帧采集不是0就是1
ret = get_grab_frame( vd,vd->frame_current);   // 获取图像数据
if( ret fd, VIDIOCSYNC, &(vd->frame_current)) frame_using[vd->frame_current] = 0 ;//采集完毕置0
return 0; 
}

unsigned char *get_frame_address(fb_v41 *vd)
{
return (vd->map + vd->mbuf.offsets[vd->frame_current]);  // 从MAP内存中找到当前帧的起始指针
}

void rgb_to_framebuffer( fb_v41 *vd,          // 
                         int width,int height,     // 图像大小
                         int xoffset,int yoffset,      // 图像在Framebuffer偏移位置
                         unsigned short  *img_ptr )  // 图像数据指针
{
  int x,y;
  int location;
  unsigned short *loca_ptr;
  // Figure out where in memory to put the pixel
    for ( y = 0; y finfo.line_length; 
    loca_ptr = (unsigned short *) (vd->fbp + location);         
     for ( x = 0; x finfo.line_length;  
      *((unsigned short int*)(vd->fbp+location ))=*img_ptr++;
    }
  } 
}
*/

int open_framebuffer(char *ptr,fb_v41 *vd)
{
  int fbfd,screensize;
    fbfd = open( ptr, O_RDWR);
    if (fbfd fbfd = fbfd; // 保存打开FrameBuffer设备的句柄

    // Get fixed screen information 获取FrameBuffer固定不变的信息
    if (ioctl(fbfd, FBIOGET_FSCREENINFO, &vd->finfo)) 
    {
    printf("Error reading fixed information.\n");
    return ERR_FRAME_BUFFER;
    }
    // Get variable screen information 获取FrameBuffer屏幕可变的信息
    if (ioctl(fbfd, FBIOGET_VSCREENINFO, &vd->vinfo)) 
    {
    printf("Error reading variable information.\n");
    return ERR_FRAME_BUFFER;
    }
    printf("%dx%d, %dbpp, xoffset=%d ,yoffset=%d \n", vd->vinfo.xres, 
       vd->vinfo.yres, vd->vinfo.bits_per_pixel,vd->vinfo.xoffset,vd->vinfo.yoffset );
    // Figure out the size of the screen in bytes
    screensize = vd->vinfo.xres * vd->vinfo.yres * vd->vinfo.bits_per_pixel / 8;
    // Map the device to memory
    vd->fbp = (char *)mmap(0,screensize,PROT_READ|PROT_WRITE,MAP_SHARED,fbfd,0); // 影射Framebuffer设备到内存
    if ((int)vd->fbp == -1) 
    {
    printf("Error: failed to map framebuffer device to memory.\n");
    return ERR_FRAME_BUFFER;
    }
    printf("The framebuffer device was mapped to memory successfully.\n");
  return  0;
}
int save_jpeg(char *buf,int x,int y,int depth)   /*保存采集到的图像到文件中*/
{ 
FILE *fp,*fp1;
static int inc=0;    
fp=fopen(DEVICE,"w+")     /*打开硬盘*/ 
char bewf[128];      /*申请一块存储区域*/
sprintf(bewf,"image-%d.jpeg",inc);   
if((fp1=fopen(bewf,"w+"))==NULL)  
{   
  perror("open");   
  exit(1);   
}   
if(depth==3)   
    fprintf(fp,"P6\n%d  %d\n255\n",x,y);   
  else if(depth==1) 
    fprintf(fp,"P5\n%d  %d\n255\n",x,y);   
  fwrite((unsigned char*)buf,x*y*depth,1,fp);   
    inc++;    /*下一帧图像的名字*/  
  fclose(fp1);   /*关闭文件*/
  fclose(fp);   /*关闭硬盘*/
} 

int open_video( char *fileptr,fb_v41 *vd ,int dep,int pal,int width,int height)
{
  // 打开视频设备
   if ((vd->fd = open(fileptr, O_RDWR)) fd, VIDIOCGCAP, &(vd->capability)) 
   printf("=============Get Device Success=======================");
  // 获取图象  
   if (ioctl(vd->fd, VIDIOCGPICT, &(vd->picture)) picture.palette = pal;  // 调色板
   vd->picture.depth = dep;   // 像素深度
//printf("=====Capture depth:%d,Palette:%d================\n",vpic.depth,vpic.palette);
   vd->mmap.format =pal;
   if (ioctl(vd->fd, VIDIOCSPICT, &(vd->picture)) mmap.width = width;   // width;
   vd->mmap.height = height;  // height;
   vd->mmap.format = vd->picture.palette; 
   vd->frame_current = 0;
   vd->frame_using[0] = 0;
   vd->frame_using[1] = 0;
   
   // 获取缓冲影射信息
   if (ioctl(vd->fd, VIDIOCGMBUF, &(vd->mbuf)) map = mmap(0, vd->mbuf.size, PROT_READ|PROT_WRITE, MAP_SHARED, vd->fd, 0);
   if ( vd->map 

int main( void )
{
  fb_v41 vd;
  int ret,i;
  unsigned short  *imageptr;
  unsigned short  tempbuf[WIDTH*HEIGHT];
  ret = open_framebuffer(FB_FILE,&vd);  // 打开FrameBuffer设备
  if( 0!= ret )              // 打开FrameBuffer设备
  {
    goto err;
  } 
  for(i=0;i
  ret = open_video( V4L_FILE, &vd ,
                    16,             // 像素深度
           VIDEO_PALETTE_RGB565,    // 设置调包板
           320,240 );
  if( 0!= ret )   // 打开视频设备失败
  {
    goto err;
  }
  
printf(vd.capability.name);printf(", Type:%d\n",vd.capability.type);
    printf("Maxwidth:%d,Maxheight:%d\n",vd.capability.maxwidth ,vd.capability.maxheight);
    printf("Minwidth:%d,Minheight:%d\n",vd.capability.minwidth,vd.capability.minheight);
    printf("Channels:%d,Audios:%d\n",vd.capability.channels,vd.capability.audios);
    printf("------Pic Size:%d-------\n",vd.mbuf.size);
  
  while(1)
  {
    imageptr = (unsigned short *) get_frame_address( &vd ); // 
    rgb_to_framebuffer(&vd,vd.mmap.width,vd.mmap.height,
                       160,120,imageptr);   // 
    if(get_next_frame( &vd ) !=0 ) 
    { // 获取图像数据出错
     goto err;
    }
  }
  
//  exit(0);
err:
if(vd.fbfd)
  close(vd.fbfd);    // 关闭FrameBuffer设备

if(vd.fd)
  close(vd.fd);
exit(0);
return 0;
}