OK6410预览并实现截图操作（RGB565）

涉及内容：1、v4l2操作摄像头2、RGB565转BMP（RGB16）文件参考代码：#include <sys/time.h>
#include <sys/types.h>
#include <asm/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include <errno.h>#include <jpeglib.h>#include <linux/fs.h>
#include <linux/kernel.h>
#include "videodev2.h"
#include <linux/fb.h> #include "jpeglib.h"#define CTRL_NUM 100#define WIDTH 480
#define HEIGHT 272
//文件头
struct tagBITMAPFILEHEADER{ unsigned long bfSize;
unsigned long bfLeft;
unsigned long bfOffBits;};
// bmp图像的位图信息头
struct tagBITMAPINFOHEADER{
unsigned long biSize;
unsigned long bmpWidth;
unsigned long bmpHeight;
unsigned short biPlanes;
unsigned short bicolors;
unsigned long isCompressed;
unsigned long biMapSize;
unsigned long biHorizontal;
unsigned long biVertical;
unsigned long biusedcolors;
unsigned long biimportcolors;
};
#define V4L2_DEV_NODE "/dev/video1"
#define FB_DEV_NODE "/dev/fb0"
typedef struct v4l2_input V_INPUT;
typedef struct v4l2_format V_FORMAT;
typedef struct v4l2_fmtdesc V_FMTDESC;
typedef struct v4l2_queryctrl V_QRYCTRL;typedef struct fb_var_screeninfo F_VINFO; #define V4L2_FMT_IN 0
#define V4L2_FMT_OUT 1
unsigned char *preview_buf;
static void writebmp（int data_fd）{
int i,j,k,size;
int ret; unsigned char *buf1 = （unsigned char *）malloc（sizeof（unsigned char） * 480*272*2）;
memcpy（buf1, preview_buf, 480*272*2）; unsigned short buf[WIDTH*HEIGHT]={0};
printf（"Write buf[i*WIDTH+k] begin！ "）;
for（i=0;i<HEIGHT;i++）
{
for（j=0;j<WIDTH;j++）
{
*（buf+i*WIDTH+j）= （buf1[i*WIDTH*2+j*2]）|（buf1[i*WIDTH*2+j*2+1]<<8）;
//if（i<1）
// printf（"（%d,%d,0x%4x） ",i,j,*（buf+i*WIDTH+j））;
}
}
printf（"Write buf[i*WIDTH+k] end！ "）;
unsigned short bmp[WIDTH*HEIGHT];

struct tagBITMAPFILEHEADER bfhead;
struct tagBITMAPINFOHEADER binfohead;
size=HEIGHT*WIDTH;

bfhead.bfSize=0x36+size*2;
bfhead.bfLeft=0;
bfhead.bfOffBits=0x36;

binfohead.biSize=0x28;
binfohead.bmpWidth=WIDTH;
binfohead.bmpHeight=HEIGHT;
binfohead.biPlanes=1;
binfohead.bicolors=0x10;
binfohead.isCompressed=0;
binfohead.biMapSize=size*2;
binfohead.biHorizontal=0x0b13;
binfohead.biVertical=0x0b13;
binfohead.biusedcolors=0;
binfohead.biimportcolors=0;

for（i=0;i<HEIGHT;i++）
for（j=0;j<WIDTH;j++）
*（bmp+i*WIDTH+j）=（（buf[（HEIGHT-i）*WIDTH-WIDTH+j]&0xf800）>>1）|（（buf[（HEIGHT-i）*WIDTH-WIDTH+j]&0x07c0）>>1）|（（buf[（HEIGHT-i）*WIDTH-WIDTH+j]&0x1f））;
//翻转图像
//for （i=HEIGHT; i>=0;i--）
// for（j=WIDTH;j>=0;j--）
// *（bmp+i*WIDTH+j）=（（buf[i*WIDTH+j]&0xf800）>>1）|（（buf[i*WIDTH+j]&0x07c0）>>1）|（（buf[i*WIDTH+j]&0x1f））;

write（data_fd,"BM",2）;
i=write（data_fd,&bfhead,sizeof（struct tagBITMAPFILEHEADER））;
printf（"Write filehead %dbytes ",i）;

i=write（data_fd,&binfohead,sizeof（struct tagBITMAPINFOHEADER））;
printf（"Write infohead %dbytes ",i）;
i=write（data_fd,bmp,size*2）;
printf（"Write bitmap %dbytes ",i）;

lseek（data_fd,SEEK_SET,4）;
}
int main（void）
{
int v4l2_fd = -1;
int fb_fd = -1;
int n=0;
__u8 *fb_buf;
__u32 screensize;
V_FORMAT fmt;
struct v4l2_capability caminfo;

v4l2_fd = open（V4L2_DEV_NODE, O_RDWR）;
if （v4l2_fd < 0） {
printf（" open video ERR "）;
} fb_fd = open（FB_DEV_NODE, O_RDWR）;
if （fb_fd < 0） {
printf（" open FB ERR "）;
}

screensize = 480 * 272 * 16 / 8;
fb_buf = （__u8 *）mmap（0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED,
fb_fd, 0）;
if （（int）fb_buf == -1） {
printf（"Error: failed to map framebuffer device to memory. "）;
close（fb_fd）;
return -1;
} if（（n =（ioctl（v4l2_fd, VIDIOC_QUERYCAP, &caminfo）））<0）
printf（"Error: failed to get camera info.%d ",n）;
//设置图象模式
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; fmt.fmt.pix.width = 480;
fmt.fmt.pix.height = 272; fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_RGB565;
fmt.fmt.pix.priv = V4L2_FMT_OUT;
if（（ioctl（v4l2_fd, VIDIOC_S_FMT, &fmt））<0）
printf（"Error: failed to set video format. "）; int type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if（（ioctl（v4l2_fd, VIDIOC_STREAMON, &type））<0）
printf（"start to get pic %d ",（int）fmt.fmt.pix.sizeimage）; int ii = 0;
while（1）{
n=read（v4l2_fd, fb_buf, 480*272*2）;
if （ii == 0 && n > 0） {
int data_fd=-1;

printf（"read Data Length:%d ", n）;
preview_buf = malloc（n）;
memcpy（preview_buf, fb_buf, n）;

char bmpfilename[30];
sprintf（bmpfilename, "/sdcard/photo%d.bmp",1）;

if（（data_fd = open（bmpfilename,O_CREAT|O_RDWR,0777））<0）{
printf（"Error: failed to creat photo.bmp. "）;
return 0;
}
printf（"bmpfilename is %s ",bmpfilename）; writebmp（data_fd）;
if（data_fd>0）
close（data_fd）;
free（preview_buf）;
ii = 1;
}
}}