videodemo.c

周立功magic2410实验箱源码 第6章Linux高级实验(part2) 6.9 IDE硬盘实验. 6.10 USB主机驱动编译与加载实验 6.11 U盘驱动程序编译与使用实验 6.12

/****************************************Copyright (c)**************************************************
**                               Guangzhou ZHIYUAN electronics Co.,LTD.
**                                     
**                                 http://www.zyinside.com
**
**--------------File Info-------------------------------------------------------------------------------
** File Name: videotest.c
** Last modified Date: 2006-01-14 
** Last Version: v1.0
** Description: 
** Note: 
**------------------------------------------------------------------------------------------------------
** Created By: 周立山
** Created date: 2006-01-01 
** Version: v1.0
** Descriptions:
**  				
**------------------------------------------------------------------------------------------------------
** Modified by:
** Modified date:
** Version:
** Description:
**
********************************************************************************************************/
// arm-linux-gcc -s -Wall -I/zylinux/kernel/include  -Wstrict-prototypes  videodemo.c  -o videodemo
#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>



#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

typedef struct	_fb_v4l
{
	// FrameBuffer 信息
	  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];
}fb_v41;

#define DEFAULT_PALETTE VIDEO_PALETTE_RGB565

#define FB_FILE "/dev/fb/0"
#define V4L_FILE "/dev/video0"

/*********************************************************************************************************
** Function name: get_grab_frame
** Descriptions: 获取图像帧，该函数调用了VIDIOCMCAPTURE的ioctl，获取一帧图片
** Input: *vd，参数指针
** 				frame,帧号
** Output : 无
** Created by:
** Created Date: 
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
int get_grab_frame(fb_v41 *vd, int frame)
{
   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)) < 0) {
      perror("v4l_grab_frame");
      return ERR_GET_FRAME;
   }
   vd->frame_using[frame] = 1;
   vd->frame_current = frame;
   return 0;
}

/*********************************************************************************************************
** Function name: get_next_frame
** Descriptions: 获取下一帧的图像
** Input: *vd ,参数指针
** Output : 无
** Created by:
** Created Date: 
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
int get_first_frame(fb_v41 *vd)
{
  int ret;
  
	vd->frame_current = 0;
	ret = get_grab_frame( vd, 0 );
	if ( ret<0 )
			return ret;
	// 等待帧同步
	if (ioctl(vd->fd, VIDIOCSYNC, &(vd->frame_current)) < 0) 
	{   perror("v4l_grab_sync");
      return ERR_SYNC;
  }
  vd->frame_using[vd->frame_current] = 0 ;		
	return (0);
}

/*********************************************************************************************************
** Function name: get_next_frame
** Descriptions: 获取下一帧的图像
** Input: *vd ,参数指针
** Output : 返回0表示正常完成返回。
** Created by:
** Created Date: 
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
int get_next_frame(fb_v41 *vd)
{
	int ret;
	vd->frame_current ^= 1;
	ret = get_grab_frame( vd,vd->frame_current);			// 获取图像数据
	if( ret < 0 )
		return ret;
		
	if (ioctl(vd->fd, VIDIOCSYNC, &(vd->frame_current)) < 0) // 等待帧同步
	{   perror("v4l_grab_sync");
      return ERR_SYNC;
  }
  vd->frame_using[vd->frame_current] = 0 ;
	return 0;	
}




/*********************************************************************************************************
** Function name: get_frame_address
** Descriptions: 获取帧地址.调用该函数可以获取当前帧的缓冲地址
** Input: *vd ,参数指针
** Output : 返回帧图像数据的指针地址.
** Created by:
** Created Date: 
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
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
}





/*********************************************************************************************************
** Function name: rgb_to_framebuffer
** Descriptions: 写图像数据到Framebuffer,使用该函数前必须成功执行open_framebuffer函数.
** Input: *vd ,参数指针
**				width,图像的宽度vd->mmap.width
**        height,图像高度
**        xoffset,图在Framebuffer X轴偏移量vd->vinfo.xoffset
**        yoffset,图在Framebuffer Y轴偏移量
**        *img_ptr,将写进FrameBuffer缓冲区指针
** Output : 无
** Created by:
** Created Date: 
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
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 < height; y++ )				// 纵扫描
		{
				location = xoffset * 2 +
					       (y + yoffset) * vd->finfo.line_length;	
				loca_ptr = (unsigned short *) (vd->fbp + location);	       	
			  for ( x = 0; x < width; x++ ) 		// 行扫描		
				{
						*(loca_ptr + x) = *img_ptr++;
				}
		}
}
/*
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 int *img_ptr )  // 图像数据指针
{
		int x,y;
		int location;
		// Figure out where in memory to put the pixel

    for ( y = 0; y < height; y++ )				// 纵扫描
		{
			  for ( x = 0; x < width; x++ ) 		// 行扫描		
				{
						location = (x + xoffset) * 2 +
					       (y + yoffset) * vd->finfo.line_length;		
						*((unsigned short int*)(vd->fbp + location )) = *img_ptr++;
				}
		}
}

*/


/*********************************************************************************************************
** Function name: open_framebuffer
** Descriptions: 该函数用于初始化FrameBuffer设备，在该函数中打开FrameBuffer设备，并将设备影射到内存
** Input: *ptr,打开Framebuffer设备路径指针
**        *vd ,参数指针
** Output : 返回非0值表示出错
** Created by:
** Created Date: 
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
int open_framebuffer(char *ptr,fb_v41 *vd)
{
		int fbfd,screensize;
     // Open the file for reading and writing
    fbfd = open( ptr, O_RDWR);
    if (fbfd < 0) 
    {
				printf("Error: cannot open framebuffer device.%x\n",fbfd);
				return ERR_FRAME_BUFFER;
    }
    printf("The framebuffer device was opened successfully.\n");
		
		vd->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;
}

/*********************************************************************************************************
** Function name: open_video
** Descriptions: 通过该函数初始化视频设备
** Input: *fileptr，打开的文件名指针
** 				*vd，参数指针
** 				dep，像素深度
** 				pal，调色板
** 				width，宽度
** 				height，高度
** Output : 无
** Created by:
** Created Date: 
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
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)) < 0) 
	 {
      perror("v4l_open:");
      return ERR_VIDEO_OPEN;
   }
   // 获取设备
   if (ioctl(vd->fd, VIDIOCGCAP, &(vd->capability)) < 0) 
   {
      perror("v4l_get_capability:");
      return ERR_VIDEO_GCAP;
   }
   

   
		// 获取图象  
   if (ioctl(vd->fd, VIDIOCGPICT, &(vd->picture)) < 0) 
   {
      perror("v4l_get_picture");
      return ERR_VIDEO_GPIC;
   }
   // 设置图象
   vd->picture.palette = pal;		// 调色板
   vd->picture.depth = dep;			// 像素深度

   vd->mmap.format =pal;
   if (ioctl(vd->fd, VIDIOCSPICT, &(vd->picture)) < 0) 
   {
      perror("v4l_set_palette");
      return ERR_VIDEO_SPIC;
   }
   // 
   vd->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)) < 0) 
   {
      perror("v4l_get_mbuf");
      return -1;
   }
   
   // 建立设备内存影射
   vd->map = mmap(0, vd->mbuf.size, PROT_READ|PROT_WRITE, MAP_SHARED, vd->fd, 0);
   if ( vd->map < 0) 
   {
      perror("v4l_mmap_init:mmap");
      return -1;
   }
       printf("The video device was opened successfully.\n");
  // return get_first_frame(vd);
  return 0;
}




/**************************************************************************************************************
**
**
***************************************************************************************************************/
int main( void )
{
		fb_v41 vd;
		int ret,i;
		unsigned short  *imageptr;
		unsigned short  tempbuf[640*480];
		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<640*480;i++)
			tempbuf[i] = 0xffff;
		rgb_to_framebuffer(&vd,640,480,0,0,tempbuf);	// 填充FrameBuffer颜色
		

		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);
		
		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;
}