static void output(int code) { cur_accum &= masks[cur_bits]; if (cur_bits > 0) cur_accum |= ((long)code << cur_bits); else cur_accum = code; cur_bits += n_bits; while( cur_bits >= 8 ) { char_out( (int)((unsigned int) cur_accum & 0xff) ); cur_accum >>= 8; cur_bits -= 8; } /* * If the next entry is going to be too big for the code size, then * increase it, if possible. */ if (free_ent > maxcode || clear_flg) { if (clear_flg) { maxcode = MAXCODE (n_bits = g_init_bits); clear_flg = 0; } else { n_bits++; if ( n_bits == maxbits ) maxcode = maxmaxcode; else maxcode = MAXCODE(n_bits); } } if (code == EOFCode) { /* At EOF, write the rest of the buffer */ while( cur_bits > 0 ) { char_out( (int)((unsigned int)cur_accum & 0xff) ); cur_accum >>= 8; cur_bits -= 8; } flush_char(); fflush( g_outfile ); #ifdef FOO if(ferror( g_outfile)) FatalError("unable to write GIF file"); #endif } }
static void output(int code, struct aap *a) { a->cur_accum &= masks[a->cur_bits]; if (a->cur_bits > 0) a->cur_accum |= ((long)code << a->cur_bits); else a->cur_accum = code; a->cur_bits += a->n_bits; while( a->cur_bits >= 8 ) { char_out( (int) (a->cur_accum & 0xff), a ); a->cur_accum >>= 8; a->cur_bits -= 8; } /* * If the next entry is going to be too big for the code size, * then increase it, if possible. */ if (a->free_ent > a->maxcode || a->clear_flg) { if( a->clear_flg ) { a->maxcode = MAXCODE (a->n_bits = a->g_init_bits); a->clear_flg = 0; } else { a->n_bits++; if ( a->n_bits == XV_BITS ) a->maxcode = (1<<XV_BITS); else a->maxcode = MAXCODE(a->n_bits); } } if( code == a->EOFCode ) { /* At EOF, write the rest of the buffer */ while( a->cur_bits > 0 ) { char_out( (int)(a->cur_accum & 0xff), a ); a->cur_accum >>= 8; a->cur_bits -= 8; } flush_char(a); fflush( a->g_outfile ); } }
LOCAL void output (gif_dest_ptr dinfo, code_int code) /* Emit a code of n_bits bits */ /* Uses cur_accum and cur_bits to reblock into 8-bit bytes */ { dinfo->cur_accum |= ((INT32) code) << dinfo->cur_bits; dinfo->cur_bits += dinfo->n_bits; while (dinfo->cur_bits >= 8) { CHAR_OUT(dinfo, dinfo->cur_accum & 0xFF); dinfo->cur_accum >>= 8; dinfo->cur_bits -= 8; } /* * If the next entry is going to be too big for the code size, * then increase it, if possible. We do this here to ensure * that it's done in sync with the decoder's codesize increases. */ if (dinfo->free_code > dinfo->maxcode) { dinfo->n_bits++; if (dinfo->n_bits == MAX_LZW_BITS) dinfo->maxcode = LZW_TABLE_SIZE; /* free_code will never exceed this */ else dinfo->maxcode = MAXCODE(dinfo->n_bits); } }
int CsObjectInt::InitComp (BYTE_TYP * outbuf, SAP_INT outlen, SAP_INT sumlen) /*--------------------------------------------------------------------*/ /* Setup header info */ /* Clear hash table */ /* Initialize static variables for compression */ /*--------------------------------------------------------------------*/ { if (outlen < CS_HEAD_SIZE) /* too small ......................*/ return CS_E_OUT_BUFFER_LEN; if (sumlen <= 0L) return CS_E_INVALID_SUMLEN; csc.clear_flg = 0; /* init compression states ........*/ csc.ratio = 0; csc.block_compress = BLOCK_MASK; csc.maxbits = CS_BITS; csc.checkpoint = CHECK_GAP; csc.maxcode = MAXCODE (csc.n_bits = INIT_CS_BITS); csc.maxmaxcode = (CODE_INT)1 << CS_BITS; csc.free_ent = ((csc.block_compress) ? FIRST : 256); csc.hsize = HSIZE; CL_HASH (csc.hsize); /* clear hash table .......................*/ /* fill in header informations ............*/ CsSetHead (outbuf, sumlen, (BYTE_TYP) ((CS_VERSION << 4) | CS_ALGORITHM), (BYTE_TYP) (csc.maxbits | csc.block_compress)); return 0; }
//----------------------------------------------------------------- // write an LZW code void mgLZWEncode::writeCode( mgLZWCode nCode) { // Uses nCurAccum and nCurBits to reblock into 8-bit bytes m_curAccum |= ((long) nCode) << m_curBits; m_curBits += m_bits; while (m_curBits >= 8) { writeLZWByte(m_curAccum & 0xFF); m_curAccum >>= 8; m_curBits -= 8; } // If the next entry is going to be too big for the code size, // then increase it, if possible. We do this here to ensure // that it's done in sync with the decoder's codesize increases. if (m_freeCode > m_maxCode) { m_bits++; if (m_bits == MAX_LZW_BITS) m_maxCode = LZW_TABLE_SIZE; // free_code will never exceed this else m_maxCode = MAXCODE(m_bits); } }
/* * Reset encoding state at the start of a strip. */ static int LZWPreEncode(TIFF* tif, uint16 s) { LZWCodecState *sp = EncoderState(tif); (void) s; assert(sp != NULL); if( sp->enc_hashtab == NULL ) { tif->tif_setupencode( tif ); } sp->lzw_nbits = BITS_MIN; sp->lzw_maxcode = MAXCODE(BITS_MIN); sp->lzw_free_ent = CODE_FIRST; sp->lzw_nextbits = 0; sp->lzw_nextdata = 0; sp->enc_checkpoint = CHECK_GAP; sp->enc_ratio = 0; sp->enc_incount = 0; sp->enc_outcount = 0; /* * The 4 here insures there is space for 2 max-sized * codes in LZWEncode and LZWPostDecode. */ sp->enc_rawlimit = tif->tif_rawdata + tif->tif_rawdatasize-1 - 4; cl_hash(sp); /* clear hash table */ sp->enc_oldcode = (hcode_t) -1; /* generates CODE_CLEAR in LZWEncode */ return (1); }
//----------------------------------------------------------------- // reset compressor and issue a clear code void mgLZWEncode::clearBlock() { clearHash(); // delete all the symbols m_freeCode = m_clearCode + 2; writeCode(m_clearCode); // inform decoder m_bits = m_initBits; // reset code size m_maxCode = MAXCODE(m_bits); }
clear_block (gif_dest_ptr dinfo) /* Reset compressor and issue a Clear code */ { clear_hash(dinfo); /* delete all the symbols */ dinfo->free_code = dinfo->ClearCode + 2; output(dinfo, dinfo->ClearCode); /* inform decoder */ dinfo->n_bits = dinfo->init_bits; /* reset code size */ dinfo->maxcode = MAXCODE(dinfo->n_bits); }
compress_init (gif_dest_ptr dinfo, int i_bits) { dinfo->n_bits = i_bits; dinfo->maxcode = MAXCODE(dinfo->n_bits); dinfo->ClearCode = (1 << (i_bits - 1)); dinfo->EOFCode = dinfo->ClearCode + 1; dinfo->code_counter = dinfo->ClearCode + 2; dinfo->bytesinpkt = 0; dinfo->cur_accum = 0; dinfo->cur_bits = 0; output(dinfo, dinfo->ClearCode); }
compress_init (gif_dest_ptr dinfo, int i_bits) /* Initialize pseudo-compressor */ { /* init all the state variables */ dinfo->n_bits = i_bits; dinfo->maxcode = MAXCODE(dinfo->n_bits); dinfo->ClearCode = (1 << (i_bits - 1)); dinfo->EOFCode = dinfo->ClearCode + 1; dinfo->code_counter = dinfo->ClearCode + 2; /* init output buffering vars */ dinfo->bytesinpkt = 0; dinfo->cur_accum = 0; dinfo->cur_bits = 0; /* GIF specifies an initial Clear code */ output(dinfo, dinfo->ClearCode); }
//----------------------------------------------------------------- // constructor mgLZWEncode::mgLZWEncode() { m_hashCode = new mgLZWCode[HASH_SIZE]; m_hashValue = new mgLZWHash[HASH_SIZE]; // init all the state variables m_bits = m_initBits = 9; // data size + 1 m_maxCode = MAXCODE(m_bits); m_clearCode = ((mgLZWCode) 1 << (m_initBits - 1)); m_EOFCode = m_clearCode + 1; m_freeCode = m_clearCode + 2; m_firstByte = TRUE; // no waiting symbol yet // init output buffering vars m_curAccum = 0; m_curBits = 0; clearHash(); // clear hash table }
compress_init (gif_dest_ptr dinfo, int i_bits) /* Initialize LZW compressor */ { /* init all the state variables */ dinfo->n_bits = dinfo->init_bits = i_bits; dinfo->maxcode = MAXCODE(dinfo->n_bits); dinfo->ClearCode = ((code_int) 1 << (i_bits - 1)); dinfo->EOFCode = dinfo->ClearCode + 1; dinfo->free_code = dinfo->ClearCode + 2; dinfo->first_byte = TRUE; /* no waiting symbol yet */ /* init output buffering vars */ dinfo->bytesinpkt = 0; dinfo->cur_accum = 0; dinfo->cur_bits = 0; /* clear hash table */ clear_hash(dinfo); /* GIF specifies an initial Clear code */ output(dinfo, dinfo->ClearCode); }
int lzwInit(lzw_streamp strm) { struct lzw_internal_state *state; hcode_t code; state = cli_malloc(sizeof(struct lzw_internal_state)); if (state == NULL) { strm->msg = "failed to allocate state"; return LZW_MEM_ERROR; } /* general state setup */ state->nbits = BITS_MIN; state->nextdata = 0; state->nextbits = 0; /* dictionary setup */ state->dec_codetab = cli_calloc(CSIZE, sizeof(code_t)); if (state->dec_codetab == NULL) { free(state); strm->msg = "failed to allocate code table"; return LZW_MEM_ERROR; } for (code = 0; code < CODE_BASIC; code++) { state->dec_codetab[code].next = NULL; state->dec_codetab[code].length = 1; state->dec_codetab[code].value = code; state->dec_codetab[code].firstchar = code; } state->dec_restart = 0; state->dec_nbitsmask = MAXCODE(BITS_MIN); state->dec_free_entp = state->dec_codetab + CODE_FIRST; state->dec_oldcodep = &state->dec_codetab[CODE_CLEAR]; state->dec_maxcodep = &state->dec_codetab[state->dec_nbitsmask-1]; strm->state = state; return LZW_OK; }
static void compress(int init_bits, FILE *outfile, byte *data, int len) { register long fcode; register int i = 0; register int c; register int ent; register int disp; register int hsize_reg; register int hshift; /* * Set up the globals: g_init_bits - initial number of bits g_outfile - * pointer to output file */ g_init_bits = init_bits; g_outfile = outfile; /* initialize 'compress' globals */ maxbits = XV_BITS; maxmaxcode = 1<<XV_BITS; memset(htab, 0, sizeof(htab)); memset(codetab, 0, sizeof(codetab)); hsize = HSIZE; free_ent = 0; clear_flg = 0; in_count = 1; out_count = 0; cur_accum = 0; cur_bits = 0; /* Set up the necessary values */ out_count = 0; clear_flg = 0; in_count = 1; maxcode = MAXCODE(n_bits = g_init_bits); ClearCode = (1 << (init_bits - 1)); EOFCode = ClearCode + 1; free_ent = ClearCode + 2; char_init(); ent = pc2nc[*data++]; len--; hshift = 0; for (fcode = (long)hsize; fcode < 65536L; fcode *= 2L ) hshift++; hshift = 8 - hshift; /* set hash code range bound */ hsize_reg = hsize; cl_hash( (count_int) hsize_reg); /* clear hash table */ output(ClearCode); while (len) { c = pc2nc[*data++]; len--; in_count++; fcode = (long)(((long) c << maxbits) + ent); i = (((int) c << hshift) ^ ent); /* xor hashing */ if ( HashTabOf (i) == fcode ) { ent = CodeTabOf (i); continue; } else if ( (long)HashTabOf (i) < 0) { /* empty slot */ goto nomatch; } disp = hsize_reg - i; /* secondary hash (after G. Knott) */ if ( i == 0 ) disp = 1; probe: if ((i -= disp) < 0) i += hsize_reg; if (HashTabOf (i) == fcode) { ent = CodeTabOf (i); continue; } if ((long)HashTabOf (i) >= 0) goto probe; nomatch: output(ent); out_count++; ent = c; if (free_ent < maxmaxcode) { CodeTabOf (i) = free_ent++; /* code -> hashtable */ HashTabOf (i) = fcode; } else { cl_block(); } } /* Put out the final code */ output(ent); out_count++; output(EOFCode); }
static int LZWDecodeCompat(TIFF* tif, tidata_t op0, tsize_t occ0, tsample_t s) { LZWCodecState *sp = DecoderState(tif); char *op = (char*) op0; long occ = (long) occ0; char *tp; u_char *bp; int code, nbits; long nextbits, nextdata, nbitsmask; code_t *codep, *free_entp, *maxcodep, *oldcodep; (void) s; assert(sp != NULL); /* * Restart interrupted output operation. */ if (sp->dec_restart) { long residue; codep = sp->dec_codep; residue = codep->length - sp->dec_restart; if (residue > occ) { /* * Residue from previous decode is sufficient * to satisfy decode request. Skip to the * start of the decoded string, place decoded * values in the output buffer, and return. */ sp->dec_restart += occ; do { codep = codep->next; } while (--residue > occ); tp = op + occ; do { *--tp = codep->value; codep = codep->next; } while (--occ); return (1); } /* * Residue satisfies only part of the decode request. */ op += residue, occ -= residue; tp = op; do { *--tp = codep->value; codep = codep->next; } while (--residue); sp->dec_restart = 0; } bp = (u_char *)tif->tif_rawcp; nbits = sp->lzw_nbits; nextdata = sp->lzw_nextdata; nextbits = sp->lzw_nextbits; nbitsmask = sp->dec_nbitsmask; oldcodep = sp->dec_oldcodep; free_entp = sp->dec_free_entp; maxcodep = sp->dec_maxcodep; while (occ > 0) { NextCode(tif, sp, bp, code, GetNextCodeCompat); if (code == CODE_EOI) break; if (code == CODE_CLEAR) { free_entp = sp->dec_codetab + CODE_FIRST; nbits = BITS_MIN; nbitsmask = MAXCODE(BITS_MIN); maxcodep = sp->dec_codetab + nbitsmask; NextCode(tif, sp, bp, code, GetNextCodeCompat); if (code == CODE_EOI) break; *op++ = (char) code, occ--; oldcodep = sp->dec_codetab + code; continue; } codep = sp->dec_codetab + code; /* * Add the new entry to the code table. */ if (free_entp < &sp->dec_codetab[0] || free_entp >= &sp->dec_codetab[CSIZE]) { TIFFError(tif->tif_name, "LZWDecodeCompat: Corrupted LZW table at scanline %d", tif->tif_row); return (0); } free_entp->next = oldcodep; if (free_entp->next < &sp->dec_codetab[0] || free_entp->next >= &sp->dec_codetab[CSIZE]) { TIFFError(tif->tif_name, "LZWDecodeCompat: Corrupted LZW table at scanline %d", tif->tif_row); return (0); } free_entp->firstchar = free_entp->next->firstchar; free_entp->length = free_entp->next->length+1; free_entp->value = (codep < free_entp) ? codep->firstchar : free_entp->firstchar; if (++free_entp > maxcodep) { if (++nbits > BITS_MAX) /* should not happen */ nbits = BITS_MAX; nbitsmask = MAXCODE(nbits); maxcodep = sp->dec_codetab + nbitsmask; } oldcodep = codep; if (code >= 256) { /* * Code maps to a string, copy string * value to output (written in reverse). */ if(codep->length == 0) { TIFFError(tif->tif_name, "LZWDecodeCompat: Wrong length of decoded " "string: data probably corrupted at scanline %d", tif->tif_row); return (0); } if (codep->length > occ) { /* * String is too long for decode buffer, * locate portion that will fit, copy to * the decode buffer, and setup restart * logic for the next decoding call. */ sp->dec_codep = codep; do { codep = codep->next; } while (codep->length > occ); sp->dec_restart = occ; tp = op + occ; do { *--tp = codep->value; codep = codep->next; } while (--occ); break; } op += codep->length, occ -= codep->length; tp = op; do { *--tp = codep->value; } while( (codep = codep->next) != NULL); } else *op++ = (char) code, occ--; } tif->tif_rawcp = (tidata_t) bp; sp->lzw_nbits = (u_short) nbits; sp->lzw_nextdata = nextdata; sp->lzw_nextbits = nextbits; sp->dec_nbitsmask = nbitsmask; sp->dec_oldcodep = oldcodep; sp->dec_free_entp = free_entp; sp->dec_maxcodep = maxcodep; if (occ > 0) { TIFFError(tif->tif_name, "LZWDecodeCompat: Not enough data at scanline %d (short %d bytes)", tif->tif_row, occ); return (0); } return (1); }
static void compress( int init_bits, FILE *outfile, ifun_t* ReadValue ) { register long fcode; register code_int i = 0; register int c; register code_int ent; register code_int disp; register code_int hsize_reg; register int hshift; /* * Set up the globals: g_init_bits - initial number of bits * g_outfile - pointer to output file */ g_init_bits = init_bits; g_outfile = outfile; /* * Set up the necessary values */ offset = 0; out_count = 0; clear_flg = 0; in_count = 1; maxcode = MAXCODE(n_bits = g_init_bits); ClearCode = (1 << (init_bits - 1)); EOFCode = ClearCode + 1; free_ent = ClearCode + 2; char_init(); ent = GIFNextPixel( ReadValue ); hshift = 0; for ( fcode = (long) hsize; fcode < 65536L; fcode *= 2L ) hshift++; hshift = 8 - hshift; /* set hash code range bound */ hsize_reg = hsize; cl_hash( (count_int) hsize_reg); /* clear hash table */ output( (code_int)ClearCode ); while ( (c = GIFNextPixel( ReadValue )) != EOF ) { in_count++; fcode = (long) (((long) c << maxbits) + ent); /* i = (((code_int)c << hshift) ~ ent); */ /* xor hashing */ i = (((code_int)c << hshift) ^ ent); /* xor hashing */ if ( HashTabOf (i) == fcode ) { ent = CodeTabOf (i); continue; } else if ( (long)HashTabOf (i) < 0 ) /* empty slot */ goto nomatch; disp = hsize_reg - i; /* secondary hash (after G. Knott) */ if ( i == 0 ) disp = 1; probe: if ( (i -= disp) < 0 ) i += hsize_reg; if ( HashTabOf (i) == fcode ) { ent = CodeTabOf (i); continue; } if ( (long)HashTabOf (i) > 0 ) goto probe; nomatch: output ( (code_int) ent ); out_count++; ent = c; if ( free_ent < maxmaxcode ) { CodeTabOf (i) = free_ent++; /* code -> hashtable */ HashTabOf (i) = fcode; } else cl_block(); } /* * Put out the final code. */ output( (code_int)ent ); out_count++; output( (code_int) EOFCode ); return; }
int decrunch_compress(xmp_file in, xmp_file out) { char_type *stackp; code_int code; int finchar; code_int oldcode; code_int incode; int inbits; int posbits; int outpos; int insize; int bitmask; code_int free_ent; code_int maxcode; code_int maxmaxcode; int n_bits; int rsize; int maxbits; int block_mode; int i; long bytes_in; /* Total number of byte from input */ long bytes_out; /* Total number of byte to output */ char_type inbuf[IBUFSIZ + 64]; /* Input buffer */ char_type outbuf[OBUFSIZ + 2048];/* Output buffer */ count_int htab[HSIZE]; unsigned short codetab[HSIZE]; bytes_in = 0; bytes_out = 0; insize = 0; rsize = xmp_fread(inbuf, 1, IBUFSIZ, in); insize += rsize; if (insize < 3 || inbuf[0] != MAGIC_1 || inbuf[1] != MAGIC_2) { return -1; } maxbits = inbuf[2] & BIT_MASK; block_mode = inbuf[2] & BLOCK_MODE; maxmaxcode = MAXCODE(maxbits); if (maxbits > BITS) { /*fprintf(stderr, "%s: compressed with %d bits, can only handle %d bits\n", (*ifname != '\0' ? ifname : "stdin"), maxbits, BITS); exit_code = 4; */ return -1; } bytes_in = insize; maxcode = MAXCODE(n_bits = INIT_BITS) - 1; bitmask = (1 << n_bits) - 1; oldcode = -1; finchar = 0; outpos = 0; posbits = 3 << 3; free_ent = ((block_mode) ? FIRST : 256); clear_tab_prefixof(); /* As above, initialize the first 256 entries in the table. */ for (code = 255; code >= 0; --code) tab_suffixof(code) = (char_type) code; do { resetbuf:; { int i; int e; int o; o = posbits >> 3; e = o <= insize ? insize - o : 0; for (i = 0; i < e; ++i) inbuf[i] = inbuf[i + o]; insize = e; posbits = 0; } if (insize < sizeof(inbuf) - IBUFSIZ) { if ((rsize = xmp_fread(inbuf + insize, 1, IBUFSIZ, in)) < 0) return -1; insize += rsize; } inbits = ((rsize > 0) ? (insize - insize % n_bits) << 3 : (insize << 3) - (n_bits - 1)); while (inbits > posbits) { if (free_ent > maxcode) { posbits = ((posbits - 1) + ((n_bits << 3) - (posbits - 1 + (n_bits << 3)) % (n_bits << 3))); ++n_bits; if (n_bits == maxbits) maxcode = maxmaxcode; else maxcode = MAXCODE(n_bits) - 1; bitmask = (1 << n_bits) - 1; goto resetbuf; } input(inbuf, posbits, code, n_bits, bitmask); if (oldcode == -1) { if (code >= 256) { fprintf(stderr, "oldcode:-1 code:%i\n", (int)(code)); fprintf(stderr, "uncompress: corrupt input\n"); /* abort_compress(); */ return -1; } outbuf[outpos++] = (char_type)(finchar = (int)(oldcode = code)); continue; } if (code == CLEAR && block_mode) { clear_tab_prefixof(); free_ent = FIRST - 1; posbits = ((posbits - 1) + ((n_bits << 3) - (posbits - 1 + (n_bits << 3)) % (n_bits << 3))); maxcode = MAXCODE(n_bits = INIT_BITS) - 1; bitmask = (1 << n_bits) - 1; goto resetbuf; } incode = code; stackp = de_stack; if (code >= free_ent) { /* Special case for KwKwK string. */ if (code > free_ent) { /*char_type *p; posbits -= n_bits; p = &inbuf[posbits >> 3]; fprintf(stderr, "insize:%d posbits:%d inbuf:%02X %02X %02X %02X %02X (%d)\n", insize, posbits, p[-1], p[0], p[1], p[2], p[3], (posbits & 07));*/ fprintf(stderr, "uncompress: corrupt input\n"); /* abort_compress(); */ return -1; } *--stackp = (char_type) finchar; code = oldcode; } while ((cmp_code_int) code >= (cmp_code_int) 256) { /* Generate output characters in reverse order */ *--stackp = tab_suffixof(code); code = tab_prefixof(code); } *--stackp = (char_type) (finchar = tab_suffixof(code)); /* And put them out in forward order */ if (outpos + (i = (de_stack - stackp)) >= OBUFSIZ) { do { if (i > OBUFSIZ - outpos) i = OBUFSIZ - outpos; if (i > 0) { memcpy(outbuf + outpos, stackp, i); outpos += i; } if (outpos >= OBUFSIZ) { if (xmp_fwrite(outbuf, 1, outpos, out) != outpos) { return -1; /*write_error(); */ } outpos = 0; } stackp += i; } while ((i = (de_stack - stackp)) > 0); } else { memcpy(outbuf + outpos, stackp, i); outpos += i; } if ((code = free_ent) < maxmaxcode) { /* Generate the new entry. */ tab_prefixof(code) = (unsigned short)oldcode; tab_suffixof(code) = (char_type) finchar; free_ent = code + 1; } oldcode = incode; /* Remember previous code. */ } bytes_in += rsize; } while (rsize > 0); if (outpos > 0 && xmp_fwrite(outbuf, 1, outpos, out) != outpos) return -1; return 0; }
void compress(void) { register long fcode; register code_int i = 0; register int c; register code_int ent; register int disp; register code_int hsize_reg; register int hshift; offset = 0; bytes_out = 3; /* includes 3-byte header mojo */ out_count = 0; clear_flg = 0; ratio = 0; in_count = 1; checkpoint = CHECK_GAP; maxcode = MAXCODE(n_bits = INIT_BITS); free_ent = ((block_compress) ? (FIRST) : (256)); ent = getbyte(); hshift = 0; for (fcode = (long) hsize; fcode < 65536L; fcode *= 2L) { hshift++; } hshift = 8 - hshift; /* set hash code range bound */ hsize_reg = hsize; cl_hash((count_int) hsize_reg); /* clear hash table */ while (InCnt > 0) { /* apsim_loop 11 0 */ int apsim_bound111 = 0; c = getbyte(); /* decrements InCnt */ in_count++; fcode = (long) (((long) c << maxbits) + ent); i = ((c << hshift) ^ ent); /* xor hashing */ if (htabof(i) == fcode) { ent = codetabof(i); continue; } else if ((long) htabof(i) < 0) { /* empty slot */ goto nomatch; } disp = hsize_reg - i; /* secondary hash (after G. Knott) */ if (i == 0) { disp = 1; } probe: if ((i -= disp) < 0) { /* apsim_loop 111 11 */ i += hsize_reg; } if (htabof(i) == fcode) { ent = codetabof(i); continue; } if ((long) htabof(i) > 0 && (++apsim_bound111 < in_count)) goto probe; nomatch: out_count++; ent = c; if (free_ent < maxmaxcode) { codetabof(i) = free_ent++; /* apsim_unknown codetab */ htabof(i) = fcode; /* apsim_unknown htab */ } else if (((count_int) in_count >= checkpoint) && (block_compress)) { cl_block(); } } if (bytes_out > in_count) { /* exit(2) if no savings */ exit_stat = 2; } return; }
/* * Open LZW file */ hidden_in_another_lib lzwFile *lzw_fdopen(int fd) { lzwFile *ret; unsigned char buf[3]; if (read(fd, buf, 3) != 3) goto err_out; if (buf[0] != LZW_MAGIC_1 || buf[1] != LZW_MAGIC_2 || buf[2] & 0x60) goto err_out; if ((ret = malloc(sizeof(*ret))) == NULL) goto err_out; memset(ret, 0x00, sizeof(*ret)); ret->fd = fd; ret->eof = 0; ret->inbuf = malloc(sizeof(unsigned char) * IN_BUFSIZE); ret->outbuf = malloc(sizeof(unsigned char) * OUT_BUFSIZE); ret->stackp = NULL; ret->insize = 3; /* we read three bytes above */ ret->outpos = 0; ret->rsize = 0; ret->flags = buf[2]; ret->maxbits = ret->flags & 0x1f; /* Mask for 'number of compresssion bits' */ ret->block_mode = ret->flags & 0x80; ret->n_bits = INIT_BITS; ret->maxcode = MAXCODE(INIT_BITS) - 1; ret->bitmask = (1<<INIT_BITS)-1; ret->oldcode = -1; ret->finchar = 0; ret->posbits = 3<<3; ret->free_ent = ((ret->block_mode) ? FIRST : 256); /* initialize the first 256 entries in the table */ memset(ret->codetab, 0x00, sizeof(ret->codetab)); for (ret->code = 255; ret->code >= 0; --ret->code) ret->htab[ret->code] = ret->code; if (ret->inbuf == NULL || ret->outbuf == NULL) { errno = ENOMEM; goto err_out_free; } if (ret->maxbits > BITS) { errno = EINVAL; goto err_out_free; } return ret; err_out: errno = EINVAL; return NULL; err_out_free: if (ret->inbuf) free(ret->inbuf); if (ret->outbuf) free(ret->outbuf); free(ret); return NULL; }
static void compress(int init_bits, gdIOCtxPtr outfile, gdImagePtr im, GifCtx *ctx) { register long fcode; register code_int i /* = 0 */; register int c; register code_int ent; register code_int disp; register code_int hsize_reg; register int hshift; /* * Set up the globals: g_init_bits - initial number of bits * g_outfile - pointer to output file */ ctx->g_init_bits = init_bits; ctx->g_outfile = outfile; /* * Set up the necessary values */ ctx->offset = 0; ctx->out_count = 0; ctx->clear_flg = 0; ctx->in_count = 1; ctx->maxcode = MAXCODE(ctx->n_bits = ctx->g_init_bits); ctx->ClearCode = (1 << (init_bits - 1)); ctx->EOFCode = ctx->ClearCode + 1; ctx->free_ent = ctx->ClearCode + 2; char_init(ctx); ent = GIFNextPixel( im, ctx ); hshift = 0; for ( fcode = (long) hsize; fcode < 65536L; fcode *= 2L ) ++hshift; hshift = 8 - hshift; /* set hash code range bound */ hsize_reg = hsize; cl_hash( (count_int) hsize_reg, ctx ); /* clear hash table */ output( (code_int)ctx->ClearCode, ctx ); #ifdef SIGNED_COMPARE_SLOW while ( (c = GIFNextPixel( im )) != (unsigned) EOF ) { #else /*SIGNED_COMPARE_SLOW*/ while ( (c = GIFNextPixel( im, ctx )) != EOF ) { /* } */ #endif /*SIGNED_COMPARE_SLOW*/ ++(ctx->in_count); fcode = (long) (((long) c << maxbits) + ent); i = (((code_int)c << hshift) ^ ent); /* xor hashing */ if ( HashTabOf (i) == fcode ) { ent = CodeTabOf (i); continue; } else if ( (long)HashTabOf (i) < 0 ) /* empty slot */ goto nomatch; disp = hsize_reg - i; /* secondary hash (after G. Knott) */ if ( i == 0 ) disp = 1; probe: if ( (i -= disp) < 0 ) i += hsize_reg; if ( HashTabOf (i) == fcode ) { ent = CodeTabOf (i); continue; } if ( (long)HashTabOf (i) > 0 ) goto probe; nomatch: output ( (code_int) ent, ctx ); ++(ctx->out_count); ent = c; #ifdef SIGNED_COMPARE_SLOW if ( (unsigned) ctx->free_ent < (unsigned) maxmaxcode) { #else /*SIGNED_COMPARE_SLOW*/ if ( ctx->free_ent < maxmaxcode ) { /* } */ #endif /*SIGNED_COMPARE_SLOW*/ CodeTabOf (i) = ctx->free_ent++; /* code -> hashtable */ HashTabOf (i) = fcode; } else cl_block(ctx); } /* * Put out the final code. */ output( (code_int)ent, ctx ); ++(ctx->out_count); output( (code_int) ctx->EOFCode, ctx ); } /***************************************************************** * TAG( output ) * * Output the given code. * Inputs: * code: A n_bits-bit integer. If == -1, then EOF. This assumes * that n_bits =< (long)wordsize - 1. * Outputs: * Outputs code to the file. * Assumptions: * Chars are 8 bits long. * Algorithm: * Maintain a GIFBITS character long buffer (so that 8 codes will * fit in it exactly). Use the VAX insv instruction to insert each * code in turn. When the buffer fills up empty it and start over. */ static const unsigned long masks[] = { 0x0000, 0x0001, 0x0003, 0x0007, 0x000F, 0x001F, 0x003F, 0x007F, 0x00FF, 0x01FF, 0x03FF, 0x07FF, 0x0FFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF }; /* Arbitrary value to mark output is done. When we see EOFCode, then we don't * expect to see any more data. If we do (e.g. corrupt image inputs), cur_bits * might be negative, so flag it to return early. */ #define CUR_BITS_FINISHED -1000 static void output(code_int code, GifCtx *ctx) { if (ctx->cur_bits == CUR_BITS_FINISHED) { return; } ctx->cur_accum &= masks[ ctx->cur_bits ]; if( ctx->cur_bits > 0 ) ctx->cur_accum |= ((long)code << ctx->cur_bits); else ctx->cur_accum = code; ctx->cur_bits += ctx->n_bits; while( ctx->cur_bits >= 8 ) { char_out( (unsigned int)(ctx->cur_accum & 0xff), ctx ); ctx->cur_accum >>= 8; ctx->cur_bits -= 8; } /* * If the next entry is going to be too big for the code size, * then increase it, if possible. */ if ( ctx->free_ent > ctx->maxcode || ctx->clear_flg ) { if( ctx->clear_flg ) { ctx->maxcode = MAXCODE (ctx->n_bits = ctx->g_init_bits); ctx->clear_flg = 0; } else { ++(ctx->n_bits); if ( ctx->n_bits == maxbits ) ctx->maxcode = maxmaxcode; else ctx->maxcode = MAXCODE(ctx->n_bits); } } if( code == ctx->EOFCode ) { /* * At EOF, write the rest of the buffer. */ while( ctx->cur_bits > 0 ) { char_out( (unsigned int)(ctx->cur_accum & 0xff), ctx); ctx->cur_accum >>= 8; ctx->cur_bits -= 8; } /* Flag that it's done to prevent re-entry. */ ctx->cur_bits = CUR_BITS_FINISHED; flush_char(ctx); } } /* * Clear out the hash table */ static void cl_block (GifCtx *ctx) /* table clear for block compress */ { cl_hash ( (count_int) hsize, ctx ); ctx->free_ent = ctx->ClearCode + 2; ctx->clear_flg = 1; output( (code_int)ctx->ClearCode, ctx); } static void cl_hash(register count_int chsize, GifCtx *ctx) /* reset code table */ { register count_int *htab_p = ctx->htab+chsize; register long i; register long m1 = -1; i = chsize - 16; do { /* might use Sys V memset(3) here */ *(htab_p-16) = m1; *(htab_p-15) = m1; *(htab_p-14) = m1; *(htab_p-13) = m1; *(htab_p-12) = m1; *(htab_p-11) = m1; *(htab_p-10) = m1; *(htab_p-9) = m1; *(htab_p-8) = m1; *(htab_p-7) = m1; *(htab_p-6) = m1; *(htab_p-5) = m1; *(htab_p-4) = m1; *(htab_p-3) = m1; *(htab_p-2) = m1; *(htab_p-1) = m1; htab_p -= 16; } while ((i -= 16) >= 0); for ( i += 16; i > 0; --i ) *--htab_p = m1; } /****************************************************************************** * * GIF Specific routines * ******************************************************************************/ /* * Set up the 'byte output' routine */ static void char_init(GifCtx *ctx) { ctx->a_count = 0; } /* * Add a character to the end of the current packet, and if it is 254 * characters, flush the packet to disk. */ static void char_out(int c, GifCtx *ctx) { ctx->accum[ ctx->a_count++ ] = c; if( ctx->a_count >= 254 ) flush_char(ctx); }
/* * Setup state for decoding a strip. */ static int LZWPreDecode(TIFF* tif, uint16 s) { static const char module[] = "LZWPreDecode"; LZWCodecState *sp = DecoderState(tif); (void) s; assert(sp != NULL); if( sp->dec_codetab == NULL ) { tif->tif_setupdecode( tif ); if( sp->dec_codetab == NULL ) return (0); } /* * Check for old bit-reversed codes. */ if (tif->tif_rawcc >= 2 && tif->tif_rawdata[0] == 0 && (tif->tif_rawdata[1] & 0x1)) { #ifdef LZW_COMPAT if (!sp->dec_decode) { TIFFWarningExt(tif->tif_clientdata, module, "Old-style LZW codes, convert file"); /* * Override default decoding methods with * ones that deal with the old coding. * Otherwise the predictor versions set * above will call the compatibility routines * through the dec_decode method. */ tif->tif_decoderow = LZWDecodeCompat; tif->tif_decodestrip = LZWDecodeCompat; tif->tif_decodetile = LZWDecodeCompat; /* * If doing horizontal differencing, must * re-setup the predictor logic since we * switched the basic decoder methods... */ (*tif->tif_setupdecode)(tif); sp->dec_decode = LZWDecodeCompat; } sp->lzw_maxcode = MAXCODE(BITS_MIN); #else /* !LZW_COMPAT */ if (!sp->dec_decode) { TIFFErrorExt(tif->tif_clientdata, module, "Old-style LZW codes not supported"); sp->dec_decode = LZWDecode; } return (0); #endif/* !LZW_COMPAT */ } else { sp->lzw_maxcode = MAXCODE(BITS_MIN)-1; sp->dec_decode = LZWDecode; } sp->lzw_nbits = BITS_MIN; sp->lzw_nextbits = 0; sp->lzw_nextdata = 0; sp->dec_restart = 0; sp->dec_nbitsmask = MAXCODE(BITS_MIN); #ifdef LZW_CHECKEOS sp->dec_bitsleft = 0; #endif sp->dec_free_entp = sp->dec_codetab + CODE_FIRST; /* * Zero entries that are not yet filled in. We do * this to guard against bogus input data that causes * us to index into undefined entries. If you can * come up with a way to safely bounds-check input codes * while decoding then you can remove this operation. */ _TIFFmemset(sp->dec_free_entp, 0, (CSIZE-CODE_FIRST)*sizeof (code_t)); sp->dec_oldcodep = &sp->dec_codetab[-1]; sp->dec_maxcodep = &sp->dec_codetab[sp->dec_nbitsmask-1]; return (1); }
int main() { register long fcode; register code_int i = 0; register int c; register code_int ent; #ifdef XENIX_16 register code_int disp; #else /* Normal machine */ register int disp; #endif register code_int hsize_reg; register int hshift; #ifndef COMPATIBLE if (nomagic == 0) { /* putchar(magic_header[0]); putchar(magic_header[1]); putchar((char)(maxbits | block_compress)); */ } #endif /* COMPATIBLE */ offset = 0; bytes_out = 3; /* includes 3-byte header mojo */ out_count = 0; clear_flg = 0; ratio = 0; in_count = 1; printf("main: bytes_out %d... hsize %d\n", (int)bytes_out, (int)hsize); checkpoint = CHECK_GAP; maxcode = MAXCODE(n_bits = INIT_BITS); free_ent = ((block_compress) ? FIRST : 256 ); ent = '\0'; /* getchar (); */ hshift = 0; for ( fcode = (long) hsize; fcode < 65536L; fcode *= 2L ) hshift++; hshift = 8 - hshift; /* set hash code range bound */ printf("main: hshift %d...\n", hshift); hsize_reg = hsize; cl_hash( (count_int) hsize_reg); /* clear hash table */ /*#ifdef SIGNED_COMPARE_SLOW while ( (c = getchar()) != (unsigned) EOF ) { #else while ( (c = getchar()) != EOF ) { #endif*/ printf("main: bytes_out %d...\n", (int)bytes_out); printf("main: hsize_reg %d...\n", (int)hsize_reg); printf("main: before compress %d...\n", (int)in_count); while (in_count < BYTES_TO_COMPRESS) { c = in_count % 255; printf("main: compressing %d...\n", (int)in_count); in_count++; fcode = (long) (((long) c << maxbits) + ent); i = (((long)c << hshift) ^ ent); /* xor hashing */ if ( htabof (i) == fcode ) { ent = codetabof (i); continue; } else if ( (long)htabof (i) < 0 ) /* empty slot */ goto nomatch; disp = hsize_reg - i; /* secondary hash (after G. Knott) */ if ( i == 0 ) disp = 1; probe: if ( (i -= disp) < 0 ) i += hsize_reg; if ( htabof (i) == fcode ) { ent = codetabof (i); continue; } if ( (long)htabof (i) > 0 ) goto probe; nomatch: output ( (code_int) ent ); out_count++; ent = c; #ifdef SIGNED_COMPARE_SLOW if ( (unsigned) free_ent < (unsigned) maxmaxcode) { #else if ( free_ent < maxmaxcode ) { #endif codetabof (i) = free_ent++; /* code -> hashtable */ htabof (i) = fcode; } else if ( (count_int)in_count >= checkpoint && block_compress ) cl_block (); } /* * Put out the final code. */ printf("main: output...\n"); output( (code_int)ent ); out_count++; output( (code_int)-1 ); if(bytes_out > in_count) /* exit(2) if no savings */ exit_stat = 2; printf("main: end...\n"); report (0xdeaddead); return 0; } /***************************************************************** * TAG( output ) * * Output the given code. * Inputs: * code: A n_bits-bit integer. If == -1, then EOF. This assumes * that n_bits =< (long)wordsize - 1. * Outputs: * Outputs code to the file. * Assumptions: * Chars are 8 bits long. * Algorithm: * Maintain a BITS character long buffer (so that 8 codes will * fit in it exactly). Use the VAX insv instruction to insert each * code in turn. When the buffer fills up empty it and start over. */ static char buf[BITS]; #ifndef vax char_type lmask[9] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80, 0x00}; char_type rmask[9] = {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff}; #endif /* vax */ void output( code ) code_int code; { /* * On the VAX, it is important to have the register declarations * in exactly the order given, or the asm will break. */ register int r_off = offset, bits= n_bits; register char * bp = buf; if ( code >= 0 ) { #ifdef vax /* VAX DEPENDENT!! Implementation on other machines is below. * * Translation: Insert BITS bits from the argument starting at * offset bits from the beginning of buf. */ 0; /* Work around for pcc -O bug with asm and if stmt */ asm( "insv 4(ap),r11,r10,(r9)" ); #else /* not a vax */ /* * byte/bit numbering on the VAX is simulated by the following code */ /* * Get to the first byte. */ bp += (r_off >> 3); r_off &= 7; /* * Since code is always >= 8 bits, only need to mask the first * hunk on the left. */ *bp = (*bp & rmask[r_off]) | ((code << r_off) & lmask[r_off]); bp++; bits -= (8 - r_off); code >>= 8 - r_off; /* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */ if ( bits >= 8 ) { *bp++ = code; code >>= 8; bits -= 8; } /* Last bits. */ if(bits) *bp = code; #endif /* vax */ offset += n_bits; if ( offset == (n_bits << 3) ) { bp = buf; bits = n_bits; bytes_out += bits; /* do putchar(*bp++); */ while(--bits); offset = 0; } /* * If the next entry is going to be too big for the code size, * then increase it, if possible. */ if ( free_ent > maxcode || (clear_flg > 0)) { /* * Write the whole buffer, because the input side won't * discover the size increase until after it has read it. */ if ( offset > 0 ) { /* if( fwrite( buf, 1, n_bits, stdout ) != n_bits) writeerr(); */ bytes_out += n_bits; } offset = 0; if ( clear_flg ) { maxcode = MAXCODE (n_bits = INIT_BITS); clear_flg = 0; } else { n_bits++; if ( n_bits == maxbits ) maxcode = maxmaxcode; else maxcode = MAXCODE(n_bits); } } } else {
int lzwInflate(lzw_streamp strm) { struct lzw_internal_state *state; uint8_t *from, *to; unsigned in, out; unsigned have, left; long nbits, nextbits, nextdata, nbitsmask; code_t *codep, *free_entp, *maxcodep, *oldcodep; uint8_t *wp; hcode_t code, free_code; int echg, ret = LZW_OK; uint32_t flags; if (strm == NULL || strm->state == NULL || strm->next_out == NULL || (strm->next_in == NULL && strm->avail_in != 0)) return LZW_STREAM_ERROR; /* load state */ to = strm->next_out; out = left = strm->avail_out; from = strm->next_in; in = have = strm->avail_in; flags = strm->flags; state = strm->state; nbits = state->nbits; nextdata = state->nextdata; nextbits = state->nextbits; nbitsmask = state->dec_nbitsmask; oldcodep = state->dec_oldcodep; free_entp = state->dec_free_entp; maxcodep = state->dec_maxcodep; echg = flags & LZW_FLAG_EARLYCHG; free_code = free_entp - &state->dec_codetab[0]; if (oldcodep == &state->dec_codetab[CODE_EOI]) return LZW_STREAM_END; /* * Restart interrupted output operation. */ if (state->dec_restart) { long residue; codep = state->dec_codep; residue = codep->length - state->dec_restart; if (residue > left) { /* * Residue from previous decode is sufficient * to satisfy decode request. Skip to the * start of the decoded string, place decoded * values in the output buffer, and return. */ state->dec_restart += left; do { codep = codep->next; } while (--residue > left); to = wp = to + left; do { *--wp = codep->value; codep = codep->next; } while (--left); goto inf_end; } /* * Residue satisfies only part of the decode request. */ to += residue, left -= residue; wp = to; do { *--wp = codep->value; codep = codep->next; } while (--residue); state->dec_restart = 0; } /* guarentee valid initial state */ if (left > 0 && (oldcodep == &state->dec_codetab[CODE_CLEAR])) { code = CODE_CLEAR; CodeClear(code); if (ret != LZW_OK) goto inf_end; } while (left > 0) { GetNextCode(code); if (code == CODE_EOI) { ret = LZW_STREAM_END; break; } if (code == CODE_CLEAR) { CodeClear(code); if (ret != LZW_OK) break; continue; } codep = state->dec_codetab + code; /* non-earlychange bit expansion */ if (!echg && free_entp > maxcodep) { if (++nbits > BITS_VALID) { flags |= LZW_FLAG_BIGDICT; if (nbits > BITS_MAX) /* should not happen */ nbits = BITS_MAX; } nbitsmask = MAXCODE(nbits); maxcodep = state->dec_codetab + nbitsmask-1; } /* * Add the new entry to the code table. */ if (&state->dec_codetab[0] > free_entp || free_entp >= &state->dec_codetab[CSIZE]) { cli_dbgmsg("%p <= %p, %p < %p(%ld)\n", &state->dec_codetab[0], free_entp, free_entp, &state->dec_codetab[CSIZE], CSIZE); strm->msg = "full dictionary, cannot add new entry"; ret = LZW_DICT_ERROR; break; } free_entp->next = oldcodep; free_entp->firstchar = free_entp->next->firstchar; free_entp->length = free_entp->next->length+1; free_entp->value = (codep < free_entp) ? codep->firstchar : free_entp->firstchar; free_entp++; /* earlychange bit expansion */ if (echg && free_entp > maxcodep) { if (++nbits > BITS_VALID) { flags |= LZW_FLAG_BIGDICT; if (nbits > BITS_MAX) /* should not happen */ nbits = BITS_MAX; } nbitsmask = MAXCODE(nbits); maxcodep = state->dec_codetab + nbitsmask-1; } free_code++; oldcodep = codep; if (code >= CODE_BASIC) { /* check if code is valid */ if (code >= free_code) { strm->msg = "cannot reference unpopulated dictionary entries"; ret = LZW_DATA_ERROR; break; } /* * Code maps to a string, copy string * value to output (written in reverse). */ if (codep->length > left) { /* * String is too long for decode buffer, * locate portion that will fit, copy to * the decode buffer, and setup restart * logic for the next decoding call. */ state->dec_codep = codep; do { codep = codep->next; } while (codep->length > left); state->dec_restart = left; to = wp = to + left; do { *--wp = codep->value; codep = codep->next; } while (--left); goto inf_end; } to += codep->length, left -= codep->length; wp = to; do { *--wp = codep->value; codep = codep->next; } while(codep != NULL); } else *to++ = code, left--; } inf_end: /* restore state */ strm->next_out = to; strm->avail_out = left; strm->next_in = from; strm->avail_in = have; strm->flags = flags; state->nbits = (uint16_t)nbits; state->nextdata = nextdata; state->nextbits = nextbits; state->dec_nbitsmask = nbitsmask; state->dec_oldcodep = oldcodep; state->dec_free_entp = free_entp; state->dec_maxcodep = maxcodep; /* update state */ in -= strm->avail_in; out -= strm->avail_out; strm->total_in += in; strm->total_out += out; if ((in == 0 && out == 0) && ret == LZW_OK) { strm->msg = "no data was processed"; ret = LZW_BUF_ERROR; } return ret; }
static void compress(int init_bits, FILE *outfile, byte *data, int len, struct GifStore *aGifStore) { register long fcode; register int i = 0; register int c; register int ent; register int disp; register int hsize_reg; register int hshift; unsigned short codetab [HSIZE]; count_int htab [HSIZE]; /* * Set up the globals: g_init_bits - initial number of bits * g_outfile - pointer to output file */ aGifStore->g_init_bits = init_bits; aGifStore->g_outfile = outfile; /* initialize 'compress' globals */ memset((char *) htab, 0, sizeof(htab)); memset((char *) codetab, 0, sizeof(codetab)); aGifStore->free_ent = 0; aGifStore->clear_flg = 0; aGifStore->cur_accum = 0; aGifStore->cur_bits = 0; /* * Set up the necessary values */ aGifStore->clear_flg = 0; aGifStore->maxcode = MAXCODE(aGifStore->n_bits = aGifStore->g_init_bits); aGifStore->ClearCode = 1 << (init_bits - 1); aGifStore->EOFCode = aGifStore->ClearCode + 1; aGifStore->free_ent = aGifStore->ClearCode + 2; aGifStore->a_count = 0; ent = aGifStore->pc2nc[*data++]; len--; hshift = 0; for ( fcode = (long)HSIZE; fcode < 65536L; fcode *= 2L ) hshift++; hshift = 8 - hshift; /* set hash code range bound */ hsize_reg = HSIZE; cl_hash2( (count_int) hsize_reg, htab); /* clear hash table */ output(aGifStore->ClearCode, aGifStore); while (len) { c = aGifStore->pc2nc[*data++]; len--; fcode = (long) ( ( (long) c << XV_BITS) + ent); i = (((int) c << hshift) ^ ent); /* xor hashing */ if ( htab[i] == fcode ) { ent = codetab[i]; continue; } else if ( (long)htab[i] < 0 ) /* empty slot */ goto nomatch; disp = hsize_reg - i; /* secondary hash (after G. Knott) */ if ( i == 0 ) disp = 1; probe: if ( (i -= disp) < 0 ) i += hsize_reg; if ( htab[i] == fcode ) { ent = codetab[i]; continue; } if ( (long)htab[i] >= 0 ) goto probe; nomatch: output(ent, aGifStore); ent = c; if ( aGifStore->free_ent < (1<<XV_BITS) ) { codetab[i] = (unsigned short)(aGifStore->free_ent++); /* code -> hashtable */ htab[i] = fcode; } else cl_block(htab, aGifStore); } /* Put out the final code */ output(ent, aGifStore); output(aGifStore->EOFCode, aGifStore); }
/*- * compress write * * Algorithm: use open addressing double hashing (no chaining) on the * prefix code / next character combination. We do a variant of Knuth's * algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime * secondary probe. Here, the modular division first probe is gives way * to a faster exclusive-or manipulation. Also do block compression with * an adaptive reset, whereby the code table is cleared when the compression * ratio decreases, but after the table fills. The variable-length output * codes are re-sized at this point, and a special CLEAR code is generated * for the decompressor. Late addition: construct the table according to * file size for noticeable speed improvement on small files. Please direct * questions about this implementation to ames!jaw. */ static int zwrite(void *cookie, const char *wbp, int num) { code_int i; int c, disp; struct s_zstate *zs; const u_char *bp; u_char tmp; int count; if (num == 0) return (0); zs = cookie; count = num; bp = wbp; if (state == S_MIDDLE) goto middle; state = S_MIDDLE; maxmaxcode = 1L << maxbits; if (fwrite(magic_header, sizeof(char), sizeof(magic_header), fp) != sizeof(magic_header)) return (-1); tmp = (u_char)((maxbits) | block_compress); if (fwrite(&tmp, sizeof(char), sizeof(tmp), fp) != sizeof(tmp)) return (-1); offset = 0; bytes_out = 3; /* Includes 3-byte header mojo. */ out_count = 0; clear_flg = 0; ratio = 0; in_count = 1; checkpoint = CHECK_GAP; maxcode = MAXCODE(n_bits = INIT_BITS); free_ent = ((block_compress) ? FIRST : 256); ent = *bp++; --count; hshift = 0; for (fcode = (long)hsize; fcode < 65536L; fcode *= 2L) hshift++; hshift = 8 - hshift; /* Set hash code range bound. */ hsize_reg = hsize; cl_hash(zs, (count_int)hsize_reg); /* Clear hash table. */ middle: for (i = 0; count--;) { c = *bp++; in_count++; fcode = (long)(((long)c << maxbits) + ent); i = ((c << hshift) ^ ent); /* Xor hashing. */ if (htabof(i) == fcode) { ent = codetabof(i); continue; } else if ((long)htabof(i) < 0) /* Empty slot. */ goto nomatch; disp = hsize_reg - i; /* Secondary hash (after G. Knott). */ if (i == 0) disp = 1; probe: if ((i -= disp) < 0) i += hsize_reg; if (htabof(i) == fcode) { ent = codetabof(i); continue; } if ((long)htabof(i) >= 0) goto probe; nomatch: if (output(zs, (code_int) ent) == -1) return (-1); out_count++; ent = c; if (free_ent < maxmaxcode) { codetabof(i) = free_ent++; /* code -> hashtable */ htabof(i) = fcode; } else if ((count_int)in_count >= checkpoint && block_compress) { if (cl_block(zs) == -1) return (-1); } } return (num); }
typedef int_64 count_int; typedef unsigned char char_type; /* * Private globals variables used by the compression and * decompression routines . */ static char_type magic_header[] = { "\037\235" }; /* 1F 9D */ static int_64 n_bits; /* Number of bits/code */ static int_64 maxbits; /* User settable max # bits/code */ static code_int maxcode; /* Maximum code, given n_bits */ static code_int maxmaxcode; /* Should NEVER generate this code */ static count_int htab [HSIZE]; /* Hash table */ static code_int hsize = HSIZE; /* Used for dynamic table sizing */ static int_64 nmask = MAXCODE(INIT_BITS); /* Used for decompression */ static int_64 obuf[2*IBUFL/4]; /* Compressed word buffer */ static int_64 cbuf[2*IBUFL]; /* Decompress: compressed buffer */ /* Compress: input buffer */ static int_64 coutbuf[2*IBUFL]; /* Compress: temp file between * _lz_output() and _lz_pack_output() * Decompress: de_stack */ static code_int free_ent = 0; /* First unused entry */ static int_64 r_off_global; static int_64 b_global; /* * Block compression parameters -- after all codes are * used up, and compression rate changes, start over.
static int LZWDecodeCompat(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s) { static const char module[] = "LZWDecodeCompat"; LZWCodecState *sp = DecoderState(tif); char *op = (char*) op0; long occ = (long) occ0; char *tp; unsigned char *bp; int code, nbits; long nextbits, nextdata, nbitsmask; code_t *codep, *free_entp, *maxcodep, *oldcodep; (void) s; assert(sp != NULL); /* Fail if value does not fit in long. */ if ((tmsize_t) occ != occ0) return (0); /* * Restart interrupted output operation. */ if (sp->dec_restart) { long residue; codep = sp->dec_codep; residue = codep->length - sp->dec_restart; if (residue > occ) { /* * Residue from previous decode is sufficient * to satisfy decode request. Skip to the * start of the decoded string, place decoded * values in the output buffer, and return. */ sp->dec_restart += occ; do { codep = codep->next; } while (--residue > occ); tp = op + occ; do { *--tp = codep->value; codep = codep->next; } while (--occ); return (1); } /* * Residue satisfies only part of the decode request. */ op += residue; occ -= residue; tp = op; do { *--tp = codep->value; codep = codep->next; } while (--residue); sp->dec_restart = 0; } bp = (unsigned char *)tif->tif_rawcp; #ifdef LZW_CHECKEOS sp->dec_bitsleft = (((uint64)tif->tif_rawcc) << 3); #endif nbits = sp->lzw_nbits; nextdata = sp->lzw_nextdata; nextbits = sp->lzw_nextbits; nbitsmask = sp->dec_nbitsmask; oldcodep = sp->dec_oldcodep; free_entp = sp->dec_free_entp; maxcodep = sp->dec_maxcodep; while (occ > 0) { NextCode(tif, sp, bp, code, GetNextCodeCompat); if (code == CODE_EOI) break; if (code == CODE_CLEAR) { do { free_entp = sp->dec_codetab + CODE_FIRST; _TIFFmemset(free_entp, 0, (CSIZE - CODE_FIRST) * sizeof (code_t)); nbits = BITS_MIN; nbitsmask = MAXCODE(BITS_MIN); maxcodep = sp->dec_codetab + nbitsmask; NextCode(tif, sp, bp, code, GetNextCodeCompat); } while (code == CODE_CLEAR); /* consecutive CODE_CLEAR codes */ if (code == CODE_EOI) break; if (code > CODE_CLEAR) { TIFFErrorExt(tif->tif_clientdata, tif->tif_name, "LZWDecode: Corrupted LZW table at scanline %d", tif->tif_row); return (0); } *op++ = (char)code; occ--; oldcodep = sp->dec_codetab + code; continue; } codep = sp->dec_codetab + code; /* * Add the new entry to the code table. */ if (free_entp < &sp->dec_codetab[0] || free_entp >= &sp->dec_codetab[CSIZE]) { TIFFErrorExt(tif->tif_clientdata, module, "Corrupted LZW table at scanline %d", tif->tif_row); return (0); } free_entp->next = oldcodep; if (free_entp->next < &sp->dec_codetab[0] || free_entp->next >= &sp->dec_codetab[CSIZE]) { TIFFErrorExt(tif->tif_clientdata, module, "Corrupted LZW table at scanline %d", tif->tif_row); return (0); } free_entp->firstchar = free_entp->next->firstchar; free_entp->length = free_entp->next->length+1; free_entp->value = (codep < free_entp) ? codep->firstchar : free_entp->firstchar; if (++free_entp > maxcodep) { if (++nbits > BITS_MAX) /* should not happen */ nbits = BITS_MAX; nbitsmask = MAXCODE(nbits); maxcodep = sp->dec_codetab + nbitsmask; } oldcodep = codep; if (code >= 256) { /* * Code maps to a string, copy string * value to output (written in reverse). */ if(codep->length == 0) { TIFFErrorExt(tif->tif_clientdata, module, "Wrong length of decoded " "string: data probably corrupted at scanline %d", tif->tif_row); return (0); } if (codep->length > occ) { /* * String is too long for decode buffer, * locate portion that will fit, copy to * the decode buffer, and setup restart * logic for the next decoding call. */ sp->dec_codep = codep; do { codep = codep->next; } while (codep->length > occ); sp->dec_restart = occ; tp = op + occ; do { *--tp = codep->value; codep = codep->next; } while (--occ); break; } assert(occ >= codep->length); op += codep->length; occ -= codep->length; tp = op; do { *--tp = codep->value; } while( (codep = codep->next) != NULL ); } else { *op++ = (char)code; occ--; } } tif->tif_rawcc -= (tmsize_t)( (uint8*) bp - tif->tif_rawcp ); tif->tif_rawcp = (uint8*) bp; sp->lzw_nbits = (unsigned short)nbits; sp->lzw_nextdata = nextdata; sp->lzw_nextbits = nextbits; sp->dec_nbitsmask = nbitsmask; sp->dec_oldcodep = oldcodep; sp->dec_free_entp = free_entp; sp->dec_maxcodep = maxcodep; if (occ > 0) { #if defined(__WIN32__) && (defined(_MSC_VER) || defined(__MINGW32__)) TIFFErrorExt(tif->tif_clientdata, module, "Not enough data at scanline %d (short %I64d bytes)", tif->tif_row, (unsigned __int64) occ); #else TIFFErrorExt(tif->tif_clientdata, module, "Not enough data at scanline %d (short %llu bytes)", tif->tif_row, (unsigned long long) occ); #endif return (0); } return (1); }
/* * Read the full COMPRESS-compressed data stream. */ Ics_Error IcsReadCompress (Ics_Header* IcsStruct, void* outbuf, size_t len) { ICSINIT; Ics_BlockRead* br = (Ics_BlockRead*)IcsStruct->BlockRead; unsigned char *stackp; long int code; int finchar; long int oldcode; long int incode; int inbits; int posbits; size_t outpos = 0; size_t insize; int bitmask; long int free_ent; long int maxcode; long int maxmaxcode; int n_bits; size_t rsize; int block_mode; int maxbits; int ii; int offset; unsigned char *inbuf = NULL; unsigned char *htab = NULL; unsigned short *codetab = NULL; /* Dynamically allocate memory that's static in (N)compress. */ inbuf = (unsigned char*)malloc (IBUFSIZ+IBUFXTRA); if (inbuf == NULL) { error = IcsErr_Alloc; goto error_exit; } htab = (unsigned char*)malloc (HSIZE*4); /* Not sure about the size of this thing, original code uses a long int array that's cast to char */ if (htab == NULL) { error = IcsErr_Alloc; goto error_exit; } codetab = (unsigned short*)malloc (HSIZE*sizeof(unsigned short)); if (codetab == NULL) { error = IcsErr_Alloc; goto error_exit; } if ((rsize = fread(inbuf, 1, IBUFSIZ, br->DataFilePtr)) <= 0) { error = IcsErr_FReadIds; goto error_exit; } insize = rsize; if (insize < 3 || inbuf[0] != MAGIC_1 || inbuf[1] != MAGIC_2) { printf("point 1!\n"); error = IcsErr_CorruptedStream; goto error_exit; } maxbits = inbuf[2] & BIT_MASK; block_mode = inbuf[2] & BLOCK_MODE; maxmaxcode = MAXCODE(maxbits); if (maxbits > BITS) { error = IcsErr_DecompressionProblem; goto error_exit; } maxcode = MAXCODE(n_bits = INIT_BITS)-1; bitmask = (1<<n_bits)-1; oldcode = -1; finchar = 0; posbits = 3<<3; free_ent = ((block_mode) ? FIRST : 256); clear_tab_prefixof(); /* As above, initialize the first 256 entries in the table. */ for (code = 255 ; code >= 0 ; --code) { tab_suffixof(code) = (unsigned char)code; } do { resetbuf: offset = posbits >> 3; insize = offset <= insize ? insize - offset : 0; for (ii = 0 ; ii < insize ; ++ii) { inbuf[ii] = inbuf[ii+offset]; } posbits = 0; if (insize < IBUFXTRA) { rsize = fread(inbuf+insize, 1, IBUFSIZ, br->DataFilePtr); if (rsize <= 0 && !feof(br->DataFilePtr)) { error = IcsErr_FReadIds; goto error_exit; } insize += rsize; } inbits = ((rsize > 0) ? (insize - insize%n_bits)<<3 : (insize<<3)-(n_bits-1)); while (inbits > posbits) { if (free_ent > maxcode) { posbits = ((posbits-1) + ((n_bits<<3) - (posbits-1+(n_bits<<3))%(n_bits<<3))); ++n_bits; if (n_bits == maxbits) { maxcode = maxmaxcode; } else { maxcode = MAXCODE(n_bits)-1; } bitmask = (1<<n_bits)-1; goto resetbuf; } input(inbuf,posbits,code,n_bits,bitmask); if (oldcode == -1) { if (code >= 256) { printf("point 3!\n"); error = IcsErr_CorruptedStream; goto error_exit; } ((unsigned char*)outbuf)[outpos++] = (unsigned char)(finchar = (int)(oldcode = code)); continue; } if (code == CLEAR && block_mode) { clear_tab_prefixof(); free_ent = FIRST - 1; posbits = ((posbits-1) + ((n_bits<<3) - (posbits-1+(n_bits<<3))%(n_bits<<3))); maxcode = MAXCODE(n_bits = INIT_BITS)-1; bitmask = (1<<n_bits)-1; goto resetbuf; } incode = code; stackp = de_stack; if (code >= free_ent) { /* Special case for KwKwK string. */ if (code > free_ent) { printf("point 4!\n"); error = IcsErr_CorruptedStream; goto error_exit; } *--stackp = (unsigned char)finchar; code = oldcode; } /* Generate output characters in reverse order */ while (code >= 256) { *--stackp = tab_suffixof(code); code = tab_prefixof(code); } *--stackp = (unsigned char)(finchar = tab_suffixof(code)); /* And put them out in forward order */ ii = de_stack-stackp; if (outpos+ii > len) { ii = len-outpos; /* do not write more in buffer than fits! */ } memcpy(((unsigned char*)outbuf)+outpos, stackp, ii); outpos += ii; if (outpos == len) { goto error_exit; } if ((code = free_ent) < maxmaxcode) { /* Generate the new entry. */ tab_prefixof(code) = (unsigned short)oldcode; tab_suffixof(code) = (unsigned char)finchar; free_ent = code+1; } oldcode = incode; /* Remember previous code. */ } } while (rsize > 0); if (outpos != len) { error = IcsErr_OutputNotFilled; } error_exit: /* Deallocate stuff */ if (inbuf) free(inbuf); if (htab) free(htab); if (codetab) free(codetab); return error; }
/* * Encode a chunk of pixels. * * Uses an open addressing double hashing (no chaining) on the * prefix code/next character combination. We do a variant of * Knuth's algorithm D (vol. 3, sec. 6.4) along with G. Knott's * relatively-prime secondary probe. Here, the modular division * first probe is gives way to a faster exclusive-or manipulation. * Also do block compression with an adaptive reset, whereby the * code table is cleared when the compression ratio decreases, * but after the table fills. The variable-length output codes * are re-sized at this point, and a CODE_CLEAR is generated * for the decoder. */ static int LZWEncode(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s) { register LZWCodecState *sp = EncoderState(tif); register long fcode; register hash_t *hp; register int h, c; hcode_t ent; long disp; long incount, outcount, checkpoint; unsigned long nextdata; long nextbits; int free_ent, maxcode, nbits; uint8* op; uint8* limit; (void) s; if (sp == NULL) return (0); assert(sp->enc_hashtab != NULL); /* * Load local state. */ incount = sp->enc_incount; outcount = sp->enc_outcount; checkpoint = sp->enc_checkpoint; nextdata = sp->lzw_nextdata; nextbits = sp->lzw_nextbits; free_ent = sp->lzw_free_ent; maxcode = sp->lzw_maxcode; nbits = sp->lzw_nbits; op = tif->tif_rawcp; limit = sp->enc_rawlimit; ent = (hcode_t)sp->enc_oldcode; if (ent == (hcode_t) -1 && cc > 0) { /* * NB: This is safe because it can only happen * at the start of a strip where we know there * is space in the data buffer. */ PutNextCode(op, CODE_CLEAR); ent = *bp++; cc--; incount++; } while (cc > 0) { c = *bp++; cc--; incount++; fcode = ((long)c << BITS_MAX) + ent; h = (c << HSHIFT) ^ ent; /* xor hashing */ #ifdef _WINDOWS /* * Check hash index for an overflow. */ if (h >= HSIZE) h -= HSIZE; #endif hp = &sp->enc_hashtab[h]; if (hp->hash == fcode) { ent = hp->code; continue; } if (hp->hash >= 0) { /* * Primary hash failed, check secondary hash. */ disp = HSIZE - h; if (h == 0) disp = 1; do { /* * Avoid pointer arithmetic because of * wraparound problems with segments. */ if ((h -= disp) < 0) h += HSIZE; hp = &sp->enc_hashtab[h]; if (hp->hash == fcode) { ent = hp->code; goto hit; } } while (hp->hash >= 0); } /* * New entry, emit code and add to table. */ /* * Verify there is space in the buffer for the code * and any potential Clear code that might be emitted * below. The value of limit is setup so that there * are at least 4 bytes free--room for 2 codes. */ if (op > limit) { tif->tif_rawcc = (tmsize_t)(op - tif->tif_rawdata); if( !TIFFFlushData1(tif) ) return 0; op = tif->tif_rawdata; } PutNextCode(op, ent); ent = (hcode_t)c; hp->code = (hcode_t)(free_ent++); hp->hash = fcode; if (free_ent == CODE_MAX-1) { /* table is full, emit clear code and reset */ cl_hash(sp); sp->enc_ratio = 0; incount = 0; outcount = 0; free_ent = CODE_FIRST; PutNextCode(op, CODE_CLEAR); nbits = BITS_MIN; maxcode = MAXCODE(BITS_MIN); } else { /* * If the next entry is going to be too big for * the code size, then increase it, if possible. */ if (free_ent > maxcode) { nbits++; assert(nbits <= BITS_MAX); maxcode = (int) MAXCODE(nbits); } else if (incount >= checkpoint) { long rat; /* * Check compression ratio and, if things seem * to be slipping, clear the hash table and * reset state. The compression ratio is a * 24+8-bit fractional number. */ checkpoint = incount+CHECK_GAP; CALCRATIO(sp, rat); if (rat <= sp->enc_ratio) { cl_hash(sp); sp->enc_ratio = 0; incount = 0; outcount = 0; free_ent = CODE_FIRST; PutNextCode(op, CODE_CLEAR); nbits = BITS_MIN; maxcode = MAXCODE(BITS_MIN); } else sp->enc_ratio = rat; } } hit: ; } /* * Restore global state. */ sp->enc_incount = incount; sp->enc_outcount = outcount; sp->enc_checkpoint = checkpoint; sp->enc_oldcode = ent; sp->lzw_nextdata = nextdata; sp->lzw_nextbits = nextbits; sp->lzw_free_ent = (unsigned short)free_ent; sp->lzw_maxcode = (unsigned short)maxcode; sp->lzw_nbits = (unsigned short)nbits; tif->tif_rawcp = op; return (1); }
/* * Setup callback. */ static int archive_compressor_compress_open(struct archive_write_filter *f) { int ret; struct private_data *state; size_t bs = 65536, bpb; f->code = ARCHIVE_COMPRESSION_COMPRESS; f->name = "compress"; ret = __archive_write_open_filter(f->next_filter); if (ret != ARCHIVE_OK) return (ret); state = (struct private_data *)calloc(1, sizeof(*state)); if (state == NULL) { archive_set_error(f->archive, ENOMEM, "Can't allocate data for compression"); return (ARCHIVE_FATAL); } if (f->archive->magic == ARCHIVE_WRITE_MAGIC) { /* Buffer size should be a multiple number of the of bytes * per block for performance. */ bpb = archive_write_get_bytes_per_block(f->archive); if (bpb > bs) bs = bpb; else if (bpb != 0) bs -= bs % bpb; } state->compressed_buffer_size = bs; state->compressed = malloc(state->compressed_buffer_size); if (state->compressed == NULL) { archive_set_error(f->archive, ENOMEM, "Can't allocate data for compression buffer"); free(state); return (ARCHIVE_FATAL); } f->write = archive_compressor_compress_write; f->close = archive_compressor_compress_close; f->free = archive_compressor_compress_free; state->max_maxcode = 0x10000; /* Should NEVER generate this code. */ state->in_count = 0; /* Length of input. */ state->bit_buf = 0; state->bit_offset = 0; state->out_count = 3; /* Includes 3-byte header mojo. */ state->compress_ratio = 0; state->checkpoint = CHECK_GAP; state->code_len = 9; state->cur_maxcode = MAXCODE(state->code_len); state->first_free = FIRST; memset(state->hashtab, 0xff, sizeof(state->hashtab)); /* Prime output buffer with a gzip header. */ state->compressed[0] = 0x1f; /* Compress */ state->compressed[1] = 0x9d; state->compressed[2] = 0x90; /* Block mode, 16bit max */ state->compressed_offset = 3; f->data = state; return (0); }