File size: 2,213 Bytes
94f6f0e | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 | /* Compressor for MEMZ and VineMEMZ
* The code has been optimized for the larger files of VineMEMZ */
#include <stdio.h>
#define BUFFER_SIZE 65536
#define LMIN 4
#define LMAX 32767
int main(int argc, char **argv) {
if (argc != 3) {
fprintf(stderr, "Usage: compress [input file] [output file]\n");
return 1;
}
FILE *infile = fopen(argv[1], "rb");
if (!infile) {
fprintf(stderr, "Could not open input file for reading.\n");
return 2;
}
unsigned char buf[BUFFER_SIZE] = { 0 };
int fsize = fread(buf, 1, BUFFER_SIZE, infile);
if (fsize >= BUFFER_SIZE) {
fprintf(stderr, "The input file is too large for compressing!\n");
return 3;
} else if (fsize <= 0) {
fprintf(stderr, "The input file is empty.\n");
return 3;
}
fclose(infile);
FILE *outfile = fopen(argv[2], "wb");
if (!outfile) {
fprintf(stderr, "Could not open output file for writing.\n");
return 2;
}
unsigned char bytes[BUFFER_SIZE] = { 0 };
int bi = 0;
int pos = 0;
while (pos < fsize) {
unsigned short l = 0, ml = 0;
int p = 0, mp = 0;
for (; p < pos; p++) {
if (buf[p] == buf[pos+l] && l < LMAX) {
l++;
} else {
if (l >= ml && (pos - p + l) < 32768) {
ml = l;
mp = p;
}
p -= l;
l = 0;
}
}
if (l >= ml && (pos - p + l) < 32768) {
ml = l;
mp = p;
}
if (ml >= LMIN) {
int bs = 0;
while (bi > 0) {
int bx = bi;
if (bx > 128) bx = 128;
unsigned char b = (1 << 7) | (bx-1);
fwrite(&b, 1, 1, outfile);
fwrite(bytes + bs, 1, bx, outfile);
bi -= bx;
bs += bx;
}
unsigned short mp2 = (pos - mp + ml);
if (ml < 64) {
char ml2 = ml;
fwrite(&ml2, 1, 1, outfile);
} else {
unsigned short ml2 = 0x4000 | ml;
ml2 = (ml2 >> 8) | (ml2 << 8);
fwrite(&ml2, 2, 1, outfile);
}
fwrite(&mp2, 2, 1, outfile);
pos += ml;
} else {
bytes[bi++] = buf[pos++];
}
printf("Position: %d/%d\n", pos, fsize);
}
int bs = 0;
while (bi > 0) {
int bx = bi;
if (bx > 128) bx = 128;
unsigned char b = (1 << 7) | (bx - 1);
fwrite(&b, 1, 1, outfile);
fwrite(bytes + bs, 1, bx, outfile);
bi -= bx;
bs += bx;
}
fclose(outfile);
return 0;
}
|