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#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include "jpeg.h"
/* getfile */
void *getfile (char *path, int *n_bytes);
static void dump_pgm (unsigned char *ptr, int rowstride, int width, int height);
int
main (int argc, char *argv[])
{
unsigned char *data;
int len;
JpegDecoder *dec;
char *fn = "biglebowski.jpg";
unsigned char *ptr;
int rowstride;
int width;
int height;
dec = jpeg_decoder_new ();
if (argc > 1)
fn = argv[1];
data = getfile (fn, &len);
jpeg_decoder_addbits (dec, data, len);
jpeg_decoder_decode (dec);
jpeg_decoder_get_component_ptr (dec, 1, &ptr, &rowstride);
jpeg_decoder_get_component_size (dec, 1, &width, &height);
dump_pgm (ptr, rowstride, width, height);
return 0;
}
/* getfile */
void *
getfile (char *path, int *n_bytes)
{
int fd;
struct stat st;
void *ptr = NULL;
int ret;
fd = open (path, O_RDONLY);
if (!fd)
return NULL;
ret = fstat (fd, &st);
if (ret < 0) {
close (fd);
return NULL;
}
ptr = malloc (st.st_size);
if (!ptr) {
close (fd);
return NULL;
}
ret = read (fd, ptr, st.st_size);
if (ret != st.st_size) {
free (ptr);
close (fd);
return NULL;
}
if (n_bytes)
*n_bytes = st.st_size;
close (fd);
return ptr;
}
static void
dump_pgm (unsigned char *ptr, int rowstride, int width, int height)
{
int x, y;
printf ("P2\n");
printf ("%d %d\n", width, height);
printf ("255\n");
for (y = 0; y < height; y++) {
for (x = 0; x < width; x++) {
printf ("%d ", ptr[x]);
if ((x & 15) == 15) {
printf ("\n");
}
}
printf ("\n");
ptr += rowstride;
}
}
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