/* ---------------------------------------------------------------------------- M. LZHuf Compression This is the LZHuf compression algorithm as used in DPBOX and F6FBB. ---------------------------------------------------------------------------- */ /************************************************************** lzhuf.c written by Haruyasu Yoshizaki 11/20/1988 some minor changes 4/6/1989 comments translated by Haruhiko Okumura 4/7/1989 minor beautifications and adjustments for compiling under Linux by Markus Gutschke 1997-01-27 Modifications to allow use as a filter by Ken Yap . 1997-07-01 Small mod to cope with running on big-endian machines by Jim Hague . 2001-04-25 **************************************************************/ #include #include #include #include #include #ifndef VERBOSE #define Fprintf(x) #define wterr 0 #else #define Fprintf(x) fprintf x #if defined(ENCODE) || defined(DECODE) static char wterr[] = "Can't write."; #ifdef ENCODE static unsigned long int codesize = 0; #endif static unsigned long int printcount = 0; #endif #endif #ifndef MAIN extern #endif FILE *infile, *outfile; #if defined(ENCODE) || defined(DECODE) static unsigned long int textsize = 0; static __inline__ void Error(char *message) { Fprintf((stderr, "\n%s\n", message)); exit(EXIT_FAILURE); } /* These will be a complete waste of time on a lo-endian */ /* system, but it only gets done once so WTF. */ static unsigned long i86ul_to_host(unsigned long ul) { unsigned long res = 0; int i; union { unsigned char c[4]; unsigned long ul; } u; u.ul = ul; for (i = 3; i >= 0; i--) res = (res << 8) + u.c[i]; return res; } static unsigned long host_to_i86ul(unsigned long ul) { int i; union { unsigned char c[4]; unsigned long ul; } u; for (i = 0; i < 4; i++) { u.c[i] = ul & 0xff; ul >>= 8; } return u.ul; } #endif /********** LZSS compression **********/ #define N 4096 /* buffer size */ /* Attention: When using this file for f6fbb-type compressed data exchange, set N to 2048 ! (DL8HBS) */ #define F 60 /* lookahead buffer size */ #define THRESHOLD 2 #define NIL N /* leaf of tree */ #if defined(ENCODE) || defined(DECODE) static unsigned char text_buf[N + F - 1]; #endif #ifdef ENCODE static int match_position, match_length, lson[N + 1], rson[N + 257], dad[N + 1]; static void InitTree(void) /* initialize trees */ { int i; for (i = N + 1; i <= N + 256; i++) rson[i] = NIL; /* root */ for (i = 0; i < N; i++) dad[i] = NIL; /* node */ } static void InsertNode(int r) /* insert to tree */ { int i, p, cmp; unsigned char *key; unsigned c; cmp = 1; key = &text_buf[r]; p = N + 1 + key[0]; rson[r] = lson[r] = NIL; match_length = 0; for ( ; ; ) { if (cmp >= 0) { if (rson[p] != NIL) p = rson[p]; else { rson[p] = r; dad[r] = p; return; } } else { if (lson[p] != NIL) p = lson[p]; else { lson[p] = r; dad[r] = p; return; } } for (i = 1; i < F; i++) if ((cmp = key[i] - text_buf[p + i]) != 0) break; if (i > THRESHOLD) { if (i > match_length) { match_position = ((r - p) & (N - 1)) - 1; if ((match_length = i) >= F) break; } if (i == match_length) { if ((c = ((r - p) & (N - 1)) - 1) < match_position) { match_position = c; } } } } dad[r] = dad[p]; lson[r] = lson[p]; rson[r] = rson[p]; dad[lson[p]] = r; dad[rson[p]] = r; if (rson[dad[p]] == p) rson[dad[p]] = r; else lson[dad[p]] = r; dad[p] = NIL; /* remove p */ } static void DeleteNode(int p) /* remove from tree */ { int q; if (dad[p] == NIL) return; /* not registered */ if (rson[p] == NIL) q = lson[p]; else if (lson[p] == NIL) q = rson[p]; else { q = lson[p]; if (rson[q] != NIL) { do { q = rson[q]; } while (rson[q] != NIL); rson[dad[q]] = lson[q]; dad[lson[q]] = dad[q]; lson[q] = lson[p]; dad[lson[p]] = q; } rson[q] = rson[p]; dad[rson[p]] = q; } dad[q] = dad[p]; if (rson[dad[p]] == p) rson[dad[p]] = q; else lson[dad[p]] = q; dad[p] = NIL; } #endif /* Huffman coding */ #define N_CHAR (256 - THRESHOLD + F) /* kinds of characters (character code = 0..N_CHAR-1) */ #define T (N_CHAR * 2 - 1) /* size of table */ #define R (T - 1) /* position of root */ #define MAX_FREQ 0x8000 /* updates tree when the */ /* root frequency comes to this value. */ typedef unsigned char uchar; /* table for encoding and decoding the upper 6 bits of position */ /* for encoding */ #ifdef ENCODE static uchar p_len[64] = { 0x03, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08 }; static uchar p_code[64] = { 0x00, 0x20, 0x30, 0x40, 0x50, 0x58, 0x60, 0x68, 0x70, 0x78, 0x80, 0x88, 0x90, 0x94, 0x98, 0x9C, 0xA0, 0xA4, 0xA8, 0xAC, 0xB0, 0xB4, 0xB8, 0xBC, 0xC0, 0xC2, 0xC4, 0xC6, 0xC8, 0xCA, 0xCC, 0xCE, 0xD0, 0xD2, 0xD4, 0xD6, 0xD8, 0xDA, 0xDC, 0xDE, 0xE0, 0xE2, 0xE4, 0xE6, 0xE8, 0xEA, 0xEC, 0xEE, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF }; #endif #ifdef DECODE /* for decoding */ static uchar d_code[256] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0C, 0x0C, 0x0C, 0x0C, 0x0D, 0x0D, 0x0D, 0x0D, 0x0E, 0x0E, 0x0E, 0x0E, 0x0F, 0x0F, 0x0F, 0x0F, 0x10, 0x10, 0x10, 0x10, 0x11, 0x11, 0x11, 0x11, 0x12, 0x12, 0x12, 0x12, 0x13, 0x13, 0x13, 0x13, 0x14, 0x14, 0x14, 0x14, 0x15, 0x15, 0x15, 0x15, 0x16, 0x16, 0x16, 0x16, 0x17, 0x17, 0x17, 0x17, 0x18, 0x18, 0x19, 0x19, 0x1A, 0x1A, 0x1B, 0x1B, 0x1C, 0x1C, 0x1D, 0x1D, 0x1E, 0x1E, 0x1F, 0x1F, 0x20, 0x20, 0x21, 0x21, 0x22, 0x22, 0x23, 0x23, 0x24, 0x24, 0x25, 0x25, 0x26, 0x26, 0x27, 0x27, 0x28, 0x28, 0x29, 0x29, 0x2A, 0x2A, 0x2B, 0x2B, 0x2C, 0x2C, 0x2D, 0x2D, 0x2E, 0x2E, 0x2F, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F, }; static uchar d_len[256] = { 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, }; #endif #if defined(ENCODE) || defined(DECODE) static unsigned freq[T + 1]; /* frequency table */ static int prnt[T + N_CHAR]; /* pointers to parent nodes, except for the */ /* elements [T..T + N_CHAR - 1] which are used to get */ /* the positions of leaves corresponding to the codes. */ static int son[T]; /* pointers to child nodes (son[], son[] + 1) */ #endif #ifdef DECODE static unsigned getbuf = 0; static uchar getlen = 0; static int GetBit(void) /* get one bit */ { int i; while (getlen <= 8) { if ((i = getc(infile)) < 0) i = 0; getbuf |= i << (8 - getlen); getlen += 8; } i = getbuf; getbuf <<= 1; getlen--; return ((signed short)i < 0); } static int GetByte(void) /* get one byte */ { unsigned short i; while (getlen <= 8) { if ((signed short)(i = getc(infile)) < 0) i = 0; getbuf |= i << (8 - getlen); getlen += 8; } i = getbuf; getbuf <<= 8; getlen -= 8; return i >> 8; } #endif #ifdef ENCODE static unsigned putbuf = 0; static uchar putlen = 0; static void Putcode(int l, unsigned c) /* output c bits of code */ { putbuf |= c >> putlen; if ((putlen += l) >= 8) { if (putc(putbuf >> 8, outfile) == EOF) { Error(wterr); } if ((putlen -= 8) >= 8) { if (putc(putbuf, outfile) == EOF) { Error(wterr); } #ifdef VERBOSE codesize += 2; #endif putlen -= 8; putbuf = c << (l - putlen); } else { putbuf <<= 8; #ifdef VERBOSE codesize++; #endif } } } #endif /* initialization of tree */ #if defined(ENCODE) || defined(DECODE) static void StartHuff(void) { int i, j; for (i = 0; i < N_CHAR; i++) { freq[i] = 1; son[i] = i + T; prnt[i + T] = i; } i = 0; j = N_CHAR; while (j <= R) { freq[j] = freq[i] + freq[i + 1]; son[j] = i; prnt[i] = prnt[i + 1] = j; i += 2; j++; } freq[T] = 0xffff; prnt[R] = 0; } /* reconstruction of tree */ static void reconst(void) { int i, j, k; unsigned f, l; /* collect leaf nodes in the first half of the table */ /* and replace the freq by (freq + 1) / 2. */ j = 0; for (i = 0; i < T; i++) { if (son[i] >= T) { freq[j] = (freq[i] + 1) / 2; son[j] = son[i]; j++; } } /* begin constructing tree by connecting sons */ for (i = 0, j = N_CHAR; j < T; i += 2, j++) { k = i + 1; f = freq[j] = freq[i] + freq[k]; for (k = j - 1; f < freq[k]; k--); k++; l = (j - k) * 2; memmove(&freq[k + 1], &freq[k], l); freq[k] = f; memmove(&son[k + 1], &son[k], l); son[k] = i; } /* connect prnt */ for (i = 0; i < T; i++) { if ((k = son[i]) >= T) { prnt[k] = i; } else { prnt[k] = prnt[k + 1] = i; } } } /* increment frequency of given code by one, and update tree */ static void update(int c) { int i, j, k, l; if (freq[R] == MAX_FREQ) { reconst(); } c = prnt[c + T]; do { k = ++freq[c]; /* if the order is disturbed, exchange nodes */ if (k > freq[l = c + 1]) { while (k > freq[++l]); l--; freq[c] = freq[l]; freq[l] = k; i = son[c]; prnt[i] = l; if (i < T) prnt[i + 1] = l; j = son[l]; son[l] = i; prnt[j] = c; if (j < T) prnt[j + 1] = c; son[c] = j; c = l; } } while ((c = prnt[c]) != 0); /* repeat up to root */ } #endif #ifdef ENCODE #if 0 static unsigned code, len; #endif static void EncodeChar(unsigned c) { unsigned i; int j, k; i = 0; j = 0; k = prnt[c + T]; /* travel from leaf to root */ do { i >>= 1; /* if node's address is odd-numbered, choose bigger brother node */ if (k & 1) i += 0x8000; j++; } while ((k = prnt[k]) != R); Putcode(j, i); #if 0 code = i; len = j; #endif update(c); } static void EncodePosition(unsigned c) { unsigned i; /* output upper 6 bits by table lookup */ i = c >> 6; Putcode(p_len[i], (unsigned)p_code[i] << 8); /* output lower 6 bits verbatim */ Putcode(6, (c & 0x3f) << 10); } static void EncodeEnd(void) { if (putlen) { if (putc(putbuf >> 8, outfile) == EOF) { Error(wterr); } #ifdef VERBOSE codesize++; #endif } } #endif #ifdef DECODE static int DecodeChar(void) { unsigned c; c = son[R]; /* travel from root to leaf, */ /* choosing the smaller child node (son[]) if the read bit is 0, */ /* the bigger (son[]+1} if 1 */ while (c < T) { c += GetBit(); c = son[c]; } c -= T; update(c); return c; } static int DecodePosition(void) { unsigned i, j, c; /* recover upper 6 bits from table */ i = GetByte(); c = (unsigned)d_code[i] << 6; j = d_len[i]; /* read lower 6 bits verbatim */ j -= 2; while (j--) { i = (i << 1) + GetBit(); } return c | (i & 0x3f); } #endif #ifdef ENCODE /* compression */ void Encode(void) /* compression */ { int i, c, len, r, s, last_match_length; unsigned long tw; fseek(infile, 0L, 2); textsize = ftell(infile); #ifdef VERBOSE if ((signed long)textsize < 0) Fprintf((stderr, "Errno: %d", errno)); #endif tw = host_to_i86ul(textsize); if (fwrite(&tw, sizeof tw, 1, outfile) < 1) Error(wterr); /* output size of text */ if (textsize == 0) return; rewind(infile); textsize = 0; /* rewind and re-read */ StartHuff(); InitTree(); s = 0; r = N - F; for (i = s; i < r; i++) text_buf[i] = ' '; for (len = 0; len < F && (c = getc(infile)) != EOF; len++) text_buf[r + len] = c; textsize = len; for (i = 1; i <= F; i++) InsertNode(r - i); InsertNode(r); do { if (match_length > len) match_length = len; if (match_length <= THRESHOLD) { match_length = 1; EncodeChar(text_buf[r]); } else { EncodeChar(255 - THRESHOLD + match_length); EncodePosition(match_position); } last_match_length = match_length; for (i = 0; i < last_match_length && (c = getc(infile)) != EOF; i++) { DeleteNode(s); text_buf[s] = c; if (s < F - 1) text_buf[s + N] = c; s = (s + 1) & (N - 1); r = (r + 1) & (N - 1); InsertNode(r); } if ((textsize += i) > printcount) { #if defined(VERBOSE) && defined(EXTRAVERBOSE) Fprintf((stderr, "%12ld\r", textsize)); #endif printcount += 1024; } while (i++ < last_match_length) { DeleteNode(s); s = (s + 1) & (N - 1); r = (r + 1) & (N - 1); if (--len) InsertNode(r); } } while (len > 0); EncodeEnd(); #ifdef LONG_REPORT Fprintf((stderr, "input size %ld bytes\n", codesize)); Fprintf((stderr, "output size %ld bytes\n", textsize)); Fprintf((stderr, "input/output %.3f\n", (double)codesize / textsize)); #else Fprintf((stderr, "input/output = %ld/%ld = %.3f\n", codesize, textsize, (double)codesize / textsize)); #endif } #endif #ifdef DECODE void Decode(void) /* recover */ { int i, j, k, r, c; unsigned long int count; unsigned long tw; if (fread(&tw, sizeof tw, 1, infile) < 1) Error("Can't read"); /* read size of text */ textsize = i86ul_to_host(tw); if (textsize == 0) return; StartHuff(); for (i = 0; i < N - F; i++) text_buf[i] = ' '; r = N - F; for (count = 0; count < textsize; ) { c = DecodeChar(); if (c < 256) { if (putc(c, outfile) == EOF) { Error(wterr); } text_buf[r++] = c; r &= (N - 1); count++; } else { i = (r - DecodePosition() - 1) & (N - 1); j = c - 255 + THRESHOLD; for (k = 0; k < j; k++) { c = text_buf[(i + k) & (N - 1)]; if (putc(c, outfile) == EOF) { Error(wterr); } text_buf[r++] = c; r &= (N - 1); count++; } } if (count > printcount) { #if defined(VERBOSE) && defined(EXTRAVERBOSE) Fprintf((stderr, "%12ld\r", count)); #endif printcount += 1024; } } Fprintf((stderr, "%12ld\n", count)); } #endif #ifdef MAIN int main(int argc, char *argv[]) { char *s; FILE *f; int c; if (argc == 2) { outfile = stdout; if ((f = tmpfile()) == NULL) { perror("tmpfile"); return EXIT_FAILURE; } while ((c = getchar()) != EOF) fputc(c, f); rewind(infile = f); } else if (argc != 4) { Fprintf((stderr, "'lzhuf e file1 file2' encodes file1 into file2.\n" "'lzhuf d file2 file1' decodes file2 into file1.\n")); return EXIT_FAILURE; } if (argc == 4) { if ((s = argv[1], s[1] || strpbrk(s, "DEde") == NULL) || (s = argv[2], (infile = fopen(s, "rb")) == NULL) || (s = argv[3], (outfile = fopen(s, "wb")) == NULL)) { Fprintf((stderr, "??? %s\n", s)); return EXIT_FAILURE; } } if (toupper(*argv[1]) == 'E') Encode(); else Decode(); fclose(infile); fclose(outfile); return EXIT_SUCCESS; } #endif