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codelength.h 991 B

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  1. /* $Id: codelength.h,v 1.1 2008/10/06 22:04:06 nanard Exp $ */
  2. /* Project : miniupnp
  3. * Author : Thomas BERNARD
  4. * copyright (c) 2005-2008 Thomas Bernard
  5. * This software is subjet to the conditions detailed in the
  6. * provided LICENCE file. */
  7. #ifndef __CODELENGTH_H__
  8. #define __CODELENGTH_H__
  9. /* Encode length by using 7bit per Byte :
  10. * Most significant bit of each byte specifies that the
  11. * following byte is part of the code */
  12. #define DECODELENGTH(n, p) n = 0; \
  13. do { n = (n << 7) | (*p & 0x7f); } \
  14. while(*(p++)&0x80);
  15. #define CODELENGTH(n, p) if(n>=268435456) *(p++) = (unsigned char)((n >> 28) | 0x80); \
  16. if(n>=2097152) *(p++) = (unsigned char)((n >> 21) | 0x80); \
  17. if(n>=16384) *(p++) = (unsigned char)((n >> 14) | 0x80); \
  18. if(n>=128) *(p++) = (unsigned char)((n >> 7) | 0x80); \
  19. *(p++) = (unsigned char)(n & 0x7f);
  20. #endif