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55 lines
1.5 KiB
C
55 lines
1.5 KiB
C
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/* $Id: codelength.h,v 1.5 2015/07/09 12:40:18 nanard Exp $ */
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/* Project : miniupnp
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* Author : Thomas BERNARD
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* copyright (c) 2005-2015 Thomas Bernard
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* This software is subjet to the conditions detailed in the
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* provided LICENCE file. */
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#ifndef CODELENGTH_H_INCLUDED
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#define CODELENGTH_H_INCLUDED
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/* Encode length by using 7bit per Byte :
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* Most significant bit of each byte specifies that the
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* following byte is part of the code */
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/* n : unsigned
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* p : unsigned char *
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*/
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#define DECODELENGTH(n, p) n = 0; \
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do { n = (n << 7) | (*p & 0x7f); } \
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while((*(p++)&0x80) && (n<(1<<25)));
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/* n : unsigned
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* READ : function/macro to read one byte (unsigned char)
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*/
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#define DECODELENGTH_READ(n, READ) \
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n = 0; \
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do { \
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unsigned char c; \
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READ(c); \
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n = (n << 7) | (c & 0x07f); \
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if(!(c&0x80)) break; \
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} while(n<(1<<25));
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/* n : unsigned
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* p : unsigned char *
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* p_limit : unsigned char *
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*/
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#define DECODELENGTH_CHECKLIMIT(n, p, p_limit) \
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n = 0; \
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do { \
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if((p) >= (p_limit)) break; \
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n = (n << 7) | (*(p) & 0x7f); \
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} while((*((p)++)&0x80) && (n<(1<<25)));
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/* n : unsigned
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* p : unsigned char *
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*/
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#define CODELENGTH(n, p) if(n>=268435456) *(p++) = (n >> 28) | 0x80; \
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if(n>=2097152) *(p++) = (n >> 21) | 0x80; \
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if(n>=16384) *(p++) = (n >> 14) | 0x80; \
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if(n>=128) *(p++) = (n >> 7) | 0x80; \
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*(p++) = n & 0x7f;
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#endif /* CODELENGTH_H_INCLUDED */
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