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integer.h 2.3 KB

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  1. /*
  2. * arbitrary precision integers
  3. * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
  4. *
  5. * This file is part of FFmpeg.
  6. *
  7. * FFmpeg is free software; you can redistribute it and/or
  8. * modify it under the terms of the GNU Lesser General Public
  9. * License as published by the Free Software Foundation; either
  10. * version 2.1 of the License, or (at your option) any later version.
  11. *
  12. * FFmpeg is distributed in the hope that it will be useful,
  13. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15. * Lesser General Public License for more details.
  16. *
  17. * You should have received a copy of the GNU Lesser General Public
  18. * License along with FFmpeg; if not, write to the Free Software
  19. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20. */
  21. /**
  22. * @file
  23. * arbitrary precision integers
  24. * @author Michael Niedermayer <michaelni@gmx.at>
  25. */
  26. #ifndef AVUTIL_INTEGER_H
  27. #define AVUTIL_INTEGER_H
  28. #include <stdint.h>
  29. #include "common.h"
  30. #define AV_INTEGER_SIZE 8
  31. typedef struct AVInteger{
  32. uint16_t v[AV_INTEGER_SIZE];
  33. } AVInteger;
  34. AVInteger av_add_i(AVInteger a, AVInteger b) av_const;
  35. AVInteger av_sub_i(AVInteger a, AVInteger b) av_const;
  36. /**
  37. * Return the rounded-down value of the base 2 logarithm of the given
  38. * AVInteger. This is simply the index of the most significant bit
  39. * which is 1, or 0 if all bits are 0.
  40. */
  41. int av_log2_i(AVInteger a) av_const;
  42. AVInteger av_mul_i(AVInteger a, AVInteger b) av_const;
  43. /**
  44. * Return 0 if a==b, 1 if a>b and -1 if a<b.
  45. */
  46. int av_cmp_i(AVInteger a, AVInteger b) av_const;
  47. /**
  48. * bitwise shift
  49. * @param s the number of bits by which the value should be shifted right,
  50. may be negative for shifting left
  51. */
  52. AVInteger av_shr_i(AVInteger a, int s) av_const;
  53. /**
  54. * Return a % b.
  55. * @param quot a/b will be stored here.
  56. */
  57. AVInteger av_mod_i(AVInteger *quot, AVInteger a, AVInteger b);
  58. /**
  59. * Return a/b.
  60. */
  61. AVInteger av_div_i(AVInteger a, AVInteger b) av_const;
  62. /**
  63. * Convert the given int64_t to an AVInteger.
  64. */
  65. AVInteger av_int2i(int64_t a) av_const;
  66. /**
  67. * Convert the given AVInteger to an int64_t.
  68. * If the AVInteger is too large to fit into an int64_t,
  69. * then only the least significant 64 bits will be used.
  70. */
  71. int64_t av_i2int(AVInteger a) av_const;
  72. #endif /* AVUTIL_INTEGER_H */