linux下usb摄像头采集的YUYV格式转换成JPEG格式的图片

由于现在部分摄像头采集的格式是YUYV，不能自己转换成jpeg的图片格式，让我们观看相当麻烦。。所以参考了mjpeg-streamer的源码。

从中取得转换函数，通过自己的组合可以实现从YUYV的格式转换成jpeg，以便于我们通过网络实施远程监控。现给出自己组合的源代码如下：

 //代码计较繁杂，没去整理，不喜勿喷。。

#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 <asm/types.h>        

#include <linux/videodev2.h>

#include <jpeglib.h>

 

#define OUTPUT_BUF_SIZE  4096

#define CLEAR(x) memset (&(x), 0, sizeof (x))

#define WIDTH 320

#define HEIGHT 240

 

struct buffer {

         void   *start;

         size_t length;

};

 

typedef struct {

  struct jpeg_destination_mgr pub;

 

  JOCTET * buffer; 

 

  unsigned char *outbuffer;

  int outbuffer_size;

  unsigned char *outbuffer_cursor;

  int *written;

 

}mjpg_destination_mgr;

 

typedef mjpg_destination_mgr *mjpg_dest_ptr;

 

static char *           dev_name        = "/dev/video0";

static int              fd              = -1;

struct buffer *         buffers         = NULL;

static unsigned int     n_buffers       = 0;

FILE *file_fd;

static unsigned long file_length;

static unsigned char *file_name;

 

METHODDEF(void) init_destination(j_compress_ptr cinfo) {

  mjpg_dest_ptr dest = (mjpg_dest_ptr) cinfo->dest;

  dest->buffer = (JOCTET *)(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, OUTPUT_BUF_SIZE * sizeof(JOCTET));

  *(dest->written) = 0;

  dest->pub.next_output_byte = dest->buffer;

  dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;

}

 

METHODDEF(boolean) empty_output_buffer(j_compress_ptr cinfo) {

  mjpg_dest_ptr dest = (mjpg_dest_ptr) cinfo->d