全志A20 a10下ov7670测试程序，拍照一张bmp图片

jiangdou · 发表于 2015-3-16 10:03:23

/*
*for a10 one video device ov7670 bmp
*by jiangdou 2014-0701
*
*
*
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <getopt.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <malloc.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <linux/videodev2.h>
#include <time.h>
#define CLEAR(x) memset (&(x), 0, sizeof (x))
typedef unsigned long DWORD;
typedef int BOOL;
typedef unsigned char BYTE;
typedef unsigned short WORD;
typedef float FLOAT;
typedef int INT;
typedef unsigned int UINT;
typedef unsigned int *PUINT;
struct buffer {
void *start;
size_t length;
};
static char *dev_name = "/dev/video0";//摄像头设备名
static int fd = -1;
struct buffer *buffers = NULL;
static unsigned int n_buffers = 0;
FILE *file_fd;
FILE *hf;
static unsigned long file_length;
static unsigned char *file_name; //全局变量和静态全局变量的区别：都是静态存储方式，但全局变量可为多个源文件共同使用，静态全局变量只在本文件中使用
//////////////////////////////////////////////////////
//获取一帧数据
//////////////////////////////////////////////////////
BYTE clip255(long v)
{
if(v < 0) v=0;
else if( v > 255) v=255;
return (BYTE)v;
}
void yuv2bmp(BYTE *YUV2buff,BYTE *RGBbuff,DWORD dwSize)
{
DWORD count;
for( count = 0; count < dwSize; count += 4 )
{
//Y0 U0 Y1 V0
BYTE Y0 = *YUV2buff;
BYTE U = *(++YUV2buff);
BYTE Y1 = *(++YUV2buff);
BYTE V = *(++YUV2buff);
++YUV2buff;
long Y,C,D,E;
BYTE R,G,B;
Y = Y0;
C = Y - 16;
D = U - 128;
E = V - 128;
R = clip255(( 298 * C + 409 * E + 128) >> 8);
G = clip255(( 298 * C - 100 * D - 208 * E + 128) >> 8);
B = clip255(( 298 * C + 516 * D + 128) >> 8);
*(RGBbuff) = B;
*(++RGBbuff) = G;
*(++RGBbuff) = R;
Y = Y1;
C = Y-16;
D = U-128;
E = V-128;
R = clip255(( 298 * C + 409 * E + 128) >> 8);
G = clip255(( 298 * C - 100 * D - 208 * E + 128) >> 8);
B = clip255(( 298 * C + 516 * D + 128) >> 8);
*(++RGBbuff) = B;
*(++RGBbuff) = G;
*(++RGBbuff) = R;
++RGBbuff;
}
}
//unsigned char a[153600];//240x320
//unsigned char rgbout[230400]="";
//unsigned char rgbout2[230400]="";
unsigned char a[614400];
unsigned char rgbout[921600]="";
unsigned char rgbout2[921600]="";
static int read_frame (void) //函数声明为static，只能在本文件中调用
{
struct v4l2_buffer buf;
unsigned int i;
CLEAR (buf);
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
ioctl (fd, VIDIOC_DQBUF, &buf); //出列采集的帧缓冲
assert (buf.index < n_buffers);
printf ("buf.index dq is %d,\n",buf.index);
fwrite(buffers[buf.index].start, buffers[buf.index].length, 1, file_fd); //将其写入文件中
ioctl (fd, VIDIOC_QBUF, &buf); //再将其入列
return 1;
}
int v4l2_get_fmt()
{
struct v4l2_format my_fmt;
}
int main (int argc,char ** argv)
{
struct v4l2_capability cap;
struct v4l2_format fmt,get_fmt;
unsigned int i;
enum v4l2_buf_type type;
unsigned int format;
file_fd = fopen("test-mmap.txt", "w");//图片文件名
fd = open (dev_name, O_RDWR | O_NONBLOCK, 0);
//ioctl (fd, VIDIOC_QUERYCAP, &cap);//获取摄像头参数
//////////////////////////////////////////////////////////////////////////////
////////////////////////开启设置device，but I die this!///////////////////////
struct v4l2_input inp;
inp.index = 0;
if (inp.type == V4L2_INPUT_TYPE_CAMERA)
printf("enuminput type is V4L2_INPUT_TYPE_CAMERA!\n");
if (-1 == ioctl (fd, VIDIOC_S_INPUT, &inp)) //设置输入index
printf("VIDIOC_S_INPUT error!\n");
/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
CLEAR (fmt);
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
fmt.fmt.pix.width = 640;//640
fmt.fmt.pix.height = 480;//480
fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV;//V4L2_PIX_FMT_RGB32;//YUYV
fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
int ff = ioctl (fd, VIDIOC_S_FMT, &fmt); //设置图像格式
if(ff<0){
printf("failture VIDIOC_S_FMT\n");
return 0;
}
printf("fmt.fmt.pix.width %d \n ",fmt.fmt.pix.width);
printf("fmt.fmt.pix.bytesperline %d \n",fmt.fmt.pix.bytesperline);
CLEAR(get_fmt);
get_fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if(-1 == ioctl(fd,VIDIOC_G_FMT,&get_fmt))
printf("failture VIDIOC_S_FMT\n");
format = fmt.fmt.pix.pixelformat;
char code[5];
int j = 0;
for(j = 0; j < 4; j++)
code[j] = (format & (0xff << j*8)) >> j*8;
code[4] = 0;
printf("format(human readble):%s\n",code);
file_length = fmt.fmt.pix.bytesperline * fmt.fmt.pix.height; //计算图片大小
printf("file_length is %d %ld",file_length,file_length);
struct v4l2_requestbuffers req;
CLEAR (req);
req.count = 4;
req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
req.memory = V4L2_MEMORY_MMAP;
ioctl (fd, VIDIOC_REQBUFS, &req); //申请缓冲，count是申请的数量
if (req.count < 2)
printf("Insufficient buffer memory\n");
buffers = calloc (req.count, sizeof (*buffers));//内存中建立对应空间
for (n_buffers = 0; n_buffers < req.count; ++n_buffers) //这个for循环内部的buf，只在此循环内有效，循环结束就没有了；
{
struct v4l2_buffer buf; //驱动中的一帧-----------
CLEAR (buf);
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
buf.index = n_buffers;
printf("buf.length is %d",buf.length);
if (-1 == ioctl (fd, VIDIOC_QUERYBUF, &buf)) //映射用户空间
printf ("VIDIOC_QUERYBUF error\n");
buffers[n_buffers].length = buf.length;
printf("buf.length %d\n\n",buf.length);
printf("buf.length is displayed");
buffers[n_buffers].start = mmap (NULL, buf.length, PROT_READ | PROT_WRITE, MAP_SHARED, fd, buf.m.offset);//通过mmap建立映射关系
if (MAP_FAILED == buffers[n_buffers].start)
printf ("mmap failed\n");
printf("buf.length is %d;",buf.length);
if (-1 == ioctl (fd, VIDIOC_QBUF, &buf))//申请到的缓冲进入列队
printf ("VIDIOC_QBUF failed\n");
printf("buf.length is %d\n.",buf.length);
}
type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (-1 == ioctl (fd, VIDIOC_STREAMON, &type)) //开始捕捉图像数据
printf ("VIDIOC_STREAMON failed\n");
else printf("VIDIOC_STREAMON succeed\n");
for (;;) //这一段涉及到异步IO
{
fd_set fds;
struct timeval tv;
int r;
FD_ZERO (&fds);//将指定的文件描述符集清空
FD_SET (fd, &fds);//在文件描述符集合中增加一个新的文件描述符
tv.tv_sec = 2;
tv.tv_usec = 0;
r = select (fd + 1, &fds, NULL, NULL, &tv);//判断是否可读（即摄像头是否准备好），tv是定时
if (-1 == r) {
if (EINTR == errno)
continue;
printf ("select err\n");
}
if (0 == r) {
fprintf (stderr, "select timeout\n");
exit (EXIT_FAILURE);
}
if (read_frame ())//如果可读，执行read_frame ()函数，并跳出循环
break;
}
unmap:
for (i = 0; i < n_buffers; ++i)
if (-1 == munmap (buffers[i].start, buffers[i].length))
printf ("munmap error");
close (fd);
fclose (file_fd);
printf("end-begin");
FILE *p;
p=fopen("test-mmap.txt","r");
fread(a,1,614400,p);
fclose(p);
unsigned char *yuv=a;
printf("1\n");
unsigned char *q=rgbout;
yuv2bmp(yuv,rgbout,614400);//153600
printf("2\n");
int j0,k;
for ( j0 =0 ; j0<480; j0++)
{
for ( k=0; k <640*3 ;k++)
{
rgbout2[k+640*j0*3] = rgbout[640*(480-j0-1)*3+k] ;
}
}
// HANDLE hf = CreateFile(
// "F://Frame.bmp", GENERIC_WRITE, FILE_SHARE_READ, NULL,
// CREATE_ALWAYS, NULL, NULL );
hf=fopen("frame.bmp","w");
if( hf == -1 )
return 0;
//if( hf == INVALID_HANDLE_VALUE )return 0;
typedef struct tagBITMAPFILEHEADER {
WORD bfType;
DWORD bfSize;
WORD bfReserved1;
WORD bfReserved2;
DWORD bfOffBits;
} BITMAPFILEHEADER;
typedef struct tagBITMAPINFOHEADER{
DWORD biSize;
long biWidth;
long biHeight;
WORD biPlanes;
WORD biBitCount;
DWORD biCompression;
DWORD biSizeImage;
long biXPelsPerMeter;
long biYPelsPerMeter;
DWORD biClrUsed;
DWORD biClrImportant;
} BITMAPINFOHEADER;
// 写文件头
BITMAPFILEHEADER bfh;
// printf("bfh1=%d\n",sizeof(WORD)+sizeof(DWORD)+sizeof(WORD)+sizeof(WORD)+sizeof(DWORD));
memset( &bfh, 0,sizeof(BITMAPFILEHEADER) );
bfh.bfType = 'MB';
bfh.bfSize = 14 + 921600 + sizeof( BITMAPINFOHEADER );
bfh.bfOffBits = 14+ sizeof( BITMAPFILEHEADER );
// DWORD dwWritten = 0;
// WriteFile( hf, &bfh, sizeof( bfh ), &dwWritten, NULL );
printf("bfh=%d\n",sizeof(BITMAPFILEHEADER));
printf("word=%d\n",sizeof(WORD));
printf("Dword=%d\n",sizeof(DWORD));
fwrite(&bfh.bfType,sizeof(WORD),1,hf);
fwrite(&bfh.bfSize,sizeof(DWORD),1,hf);
fwrite(&bfh.bfReserved1,sizeof(WORD),1,hf);
fwrite(&bfh.bfReserved2,sizeof(WORD),1,hf);
fwrite(&bfh.bfOffBits,sizeof(DWORD),1,hf);
// 写位图格式
BITMAPINFOHEADER bih;
memset( &bih, 0, sizeof( bih ) );
bih.biSize = sizeof( bih );
bih.biWidth =640;
bih.biHeight = 480;
bih.biPlanes = 1;
bih.biBitCount = 24;
fwrite(&bih,sizeof(bih),1,hf);
// printf("bih=%d\n",sizeof(bih));
//WriteFile( hf, &bih, sizeof( bih ), &dwWritten, NULL );
// 写位图数据
//WriteFile( hf, rgbout2, 921600, &dwWritten, NULL );
// CloseHandle( hf );
fwrite(rgbout2,921600,1,hf);//230400
fclose(hf);
//exit (EXIT_SUCCESS);
return 0;
}

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全志A20 a10下ov7670测试程序，拍照一张bmp图片

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