39 lines
1.2 KiB
C
39 lines
1.2 KiB
C
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#include <stdio.h>
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#include <stdlib.h>
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typedef struct {
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unsigned long *icod,*ncod,*left,*right,nch,nodemax;
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} huffcode;
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void hufenc(unsigned long ich, unsigned char **codep, unsigned long *lcode,
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unsigned long *nb, huffcode *hcode)
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{
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void nrerror(char error_text[]);
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int l,n;
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unsigned long k,nc;
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static unsigned long setbit[32]={0x1L,0x2L,0x4L,0x8L,0x10L,0x20L,
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0x40L,0x80L,0x100L,0x200L,0x400L,0x800L,0x1000L,0x2000L,
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0x4000L,0x8000L,0x10000L,0x20000L,0x40000L,0x80000L,0x100000L,
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0x200000L,0x400000L,0x800000L,0x1000000L,0x2000000L,0x4000000L,
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0x8000000L,0x10000000L,0x20000000L,0x40000000L,0x80000000L};
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k=ich+1;
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if (k > hcode->nch || k < 1) nrerror("ich out of range in hufenc.");
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for (n=hcode->ncod[k]-1;n>=0;n--,++(*nb)) {
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nc=(*nb >> 3);
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if (++nc >= *lcode) {
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fprintf(stderr,"Reached the end of the 'code' array.\n");
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fprintf(stderr,"Attempting to expand its size.\n");
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*lcode *= 1.5;
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if ((*codep=(unsigned char *)realloc(*codep,
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(unsigned)(*lcode*sizeof(unsigned char)))) == NULL) {
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nrerror("Size expansion failed.");
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}
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}
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l=(*nb) & 7;
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if (!l) (*codep)[nc]=0;
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if (hcode->icod[k] & setbit[n]) (*codep)[nc] |= setbit[l];
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}
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}
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