LZW压缩算法源代码.docVIP

COMMFUNC.h源码 #define BUF_SIZE 0x10000 #define EMPTY 0xFFFFFFFF #define UEOF 0xFFFF #define NOT_FIND 0xFFFF void InitTable(); UINT UpdateTable(UINT prevcode , BYTE c); UINT QueryTable(UINT code , BYTE c); UINT readc(FILE *fp); void putcode(FILE *fp, UINT code); void flushout(FILE *fp); COMMFUNC.c源码 #include lzwcom3.h #include commfunc.h UINT currentpos = INIT_SIZE ; extern ENTRY string_tab[TAB_SIZE]; BYTE inputbuf[BUF_SIZE]; int inpindex = EMPTY, limit; BYTE outputbuf[BUF_SIZE]; int oupindex = 0 ,tempcode = EMPTY; void InitTable() { int i; for(i = 0 ; i TAB_SIZE ;i++) string_tab[i].used = FALSE ,string_tab[i].prev = NO_PREV, string_tab[i].c= 0; for(i = 0 ; i INIT_SIZE ; i++) { string_tab[i].used = TRUE; string_tab[i].c = i; } } UINT UpdateTable(UINT prevcode , BYTE c) { if(currentpos = TAB_SIZE || prevcode = TAB_SIZE -1) return NOT_FIND; string_tab[currentpos].used = TRUE; string_tab[currentpos].prev = prevcode; string_tab[currentpos].c = c; return currentpos++; } UINT QueryTable(UINT code , BYTE c) { register ENTRY *u; UINT i; if(code == NO_PREV) return c; for(i = code +1 ; i currentpos ; i++) { u = string_tab[i]; if(u-used u-prev==code u-c == c) return i; } return NOT_FIND; } UINT GetChars(UINT code , char *buffer , UINT size) { UINT i =0; if(!string_tab[code].used) return 0; while(string_tab[code].prev != NO_PREV) { buffer[size-1-i++] = string_tab[code].c; code =string_tab[code].prev; } buffer[size-1-i++] = string_tab[code].c; memmove(buffer , buffer[size - i] , i); buffer[i] = \0; return i; } UINT readc(FILE *fp) { static int count= 0; if(inpindex == EMPTY) { putchar(.); count++; if(count%80==0) printf(\n); if((limit =fread(inputbuf , sizeof(char) ,BUF_SIZE , fp))==0) return UEOF; inpindex = 0; return inputbuf[inpindex++]; } else { if(inpindex == limit) { inpindex = EMPTY; return readc(fp); } return