mirror of
https://github.com/reactos/reactos.git
synced 2024-07-02 02:34:53 +00:00
119 lines
2.7 KiB
C
119 lines
2.7 KiB
C
/* ------------------- huffc.c -------------------- */
|
|
|
|
#include "dflat.h"
|
|
#include "htree.h"
|
|
|
|
extern struct DfHTree *ht;
|
|
extern int root;
|
|
extern int treect;
|
|
static int lastchar = '\n';
|
|
|
|
static void compress(FILE *, int, int);
|
|
static void outbit(FILE *fo, int bit);
|
|
|
|
static int fgetcx(FILE *fi)
|
|
{
|
|
int c;
|
|
|
|
/* ------- bypass comments ------- */
|
|
if ((c = fgetc(fi)) == ';' && lastchar == '\n')
|
|
do {
|
|
while (c != '\n' && c != EOF)
|
|
c = fgetc(fi);
|
|
} while (c == ';');
|
|
lastchar = c;
|
|
return c;
|
|
}
|
|
|
|
void main(int argc, char *argv[])
|
|
{
|
|
FILE *fi, *fo;
|
|
int c;
|
|
DF_BYTECOUNTER bytectr = 0;
|
|
|
|
if (argc < 3) {
|
|
printf("\nusage: huffc infile outfile");
|
|
exit(1);
|
|
}
|
|
|
|
if ((fi = fopen(argv[1], "rb")) == NULL) {
|
|
printf("\nCannot open %s", argv[1]);
|
|
exit(1);
|
|
}
|
|
if ((fo = fopen(argv[2], "wb")) == NULL) {
|
|
printf("\nCannot open %s", argv[2]);
|
|
fclose(fi);
|
|
exit(1);
|
|
}
|
|
|
|
ht = calloc(256, sizeof(struct DfHTree));
|
|
|
|
/* - read the input file and count character frequency - */
|
|
while ((c = fgetcx(fi)) != EOF) {
|
|
c &= 255;
|
|
ht[c].cnt++;
|
|
bytectr++;
|
|
}
|
|
|
|
/* ---- build the huffman tree ---- */
|
|
DfBuildTree();
|
|
|
|
/* --- write the byte count to the output file --- */
|
|
fwrite(&bytectr, sizeof bytectr, 1, fo);
|
|
|
|
/* --- write the tree count to the output file --- */
|
|
fwrite(&treect, sizeof treect, 1, fo);
|
|
|
|
/* --- write the root offset to the output file --- */
|
|
fwrite(&root, sizeof root, 1, fo);
|
|
|
|
/* -- write the tree to the output file -- */
|
|
for (c = 256; c < treect; c++) {
|
|
int lf = ht[c].left;
|
|
int rt = ht[c].right;
|
|
fwrite(&lf, sizeof lf, 1, fo);
|
|
fwrite(&rt, sizeof rt, 1, fo);
|
|
}
|
|
|
|
/* ------ compress the file ------ */
|
|
fseek(fi, 0L, 0);
|
|
while ((c = fgetcx(fi)) != EOF)
|
|
compress(fo, (c & 255), 0);
|
|
outbit(fo, -1);
|
|
fclose(fi);
|
|
fclose(fo);
|
|
free(ht);
|
|
exit(0);
|
|
}
|
|
|
|
/* ---- compress a character value into a bit stream ---- */
|
|
static void compress(FILE *fo, int h, int child)
|
|
{
|
|
if (ht[h].parent != -1)
|
|
compress(fo, ht[h].parent, h);
|
|
if (child) {
|
|
if (child == ht[h].right)
|
|
outbit(fo, 0);
|
|
else if (child == ht[h].left)
|
|
outbit(fo, 1);
|
|
}
|
|
}
|
|
|
|
static char out8;
|
|
static int ct8;
|
|
|
|
/* -- collect and write bits to the compressed output file -- */
|
|
static void outbit(FILE *fo, int bit)
|
|
{
|
|
if (ct8 == 8 || bit == -1) {
|
|
while (ct8 < 8) {
|
|
out8 <<= 1;
|
|
ct8++;
|
|
}
|
|
fputc(out8, fo);
|
|
ct8 = 0;
|
|
}
|
|
out8 = (out8 << 1) | bit;
|
|
ct8++;
|
|
}
|