libjpeg 사용시 컴파일 오류에 대해서 질문합니다.

#include <stdio.h>
#include "jpeglib.h"
#include <setjmp.h>
 
extern JSAMPLE * image_buffer;	/* Points to large array of R,G,B-order data */
extern int image_height;	/* Number of rows in image */
extern int image_width;		/* Number of columns in image */
 
GLOBAL(void)
write_JPEG_file (char * filename, int quality)
{
  struct jpeg_compress_struct cinfo;
  struct jpeg_error_mgr jerr;
  FILE * outfile;		/* target file */
  JSAMPROW row_pointer[1];	/* pointer to JSAMPLE row[s] */
  int row_stride;		/* physical row width in image buffer */
 
  cinfo.err = jpeg_std_error(&jerr);
  jpeg_create_compress(&cinfo);
 
  if ((outfile = fopen(filename, "wb")) == NULL) {
    fprintf(stderr, "can't open %s\n", filename);
    exit(1);
  }
  jpeg_stdio_dest(&cinfo, outfile);
 
  cinfo.image_width = image_width; 	/* image width and height, in pixels */
  cinfo.image_height = image_height;
  cinfo.input_components = 3;		/* # of color components per pixel */
  cinfo.in_color_space = JCS_RGB; 	/* colorspace of input image */
  jpeg_set_defaults(&cinfo);
 
  jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */);
 
  jpeg_start_compress(&cinfo, TRUE);
 
  row_stride = image_width * 3;	/* JSAMPLEs per row in image_buffer */
 
  while (cinfo.next_scanline < cinfo.image_height) {
    row_pointer[0] = & image_buffer[cinfo.next_scanline * row_stride];
    (void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
  }
 
  jpeg_finish_compress(&cinfo);
  fclose(outfile);
 
  jpeg_destroy_compress(&cinfo);
}
 
struct my_error_mgr {
  struct jpeg_error_mgr pub;	/* "public" fields */
 
  jmp_buf setjmp_buffer;	/* for return to caller */
};
 
typedef struct my_error_mgr * my_error_ptr;
 
METHODDEF(void)
my_error_exit (j_common_ptr cinfo)
{
  my_error_ptr myerr = (my_error_ptr) cinfo->err;
  (*cinfo->err->output_message) (cinfo);
  longjmp(myerr->setjmp_buffer, 1);
}
 
GLOBAL(int)
read_JPEG_file (char * filename)
{
  struct jpeg_decompress_struct cinfo;
  struct my_error_mgr jerr;
  /* More stuff */
  FILE * infile;		/* source file */
  JSAMPARRAY buffer;		/* Output row buffer */
  int row_stride;		/* physical row width in output buffer */
  if ((infile = fopen(filename, "rb")) == NULL) {
    fprintf(stderr, "can't open %s\n", filename);
    return 0;
  }
 
  cinfo.err = jpeg_std_error(&jerr.pub);
  jerr.pub.error_exit = my_error_exit;
  if (setjmp(jerr.setjmp_buffer)) {
    jpeg_destroy_decompress(&cinfo);
    fclose(infile);
    return 0;
  }
  jpeg_create_decompress(&cinfo);
 
  jpeg_stdio_src(&cinfo, infile);
 
  (void) jpeg_read_header(&cinfo, TRUE);
 
  (void) jpeg_start_decompress(&cinfo);
  row_stride = cinfo.output_width * cinfo.output_components;
  buffer = (*cinfo.mem->alloc_sarray)
		((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);
 
  while (cinfo.output_scanline < cinfo.output_height) {
    (void) jpeg_read_scanlines(&cinfo, buffer, 1);
    put_scanline_someplace(buffer[0], row_stride);
  }
 
  (void) jpeg_finish_decompress(&cinfo);
 
  jpeg_destroy_decompress(&cinfo);
  fclose(infile);
  return 1;
}
 
int main(void) {
	return 0;
}