celp_math.h 2.7 KB

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  1. /*
  2. * Various fixed-point math operations
  3. *
  4. * Copyright (c) 2008 Vladimir Voroshilov
  5. *
  6. * This file is part of FFmpeg.
  7. *
  8. * FFmpeg is free software; you can redistribute it and/or
  9. * modify it under the terms of the GNU Lesser General Public
  10. * License as published by the Free Software Foundation; either
  11. * version 2.1 of the License, or (at your option) any later version.
  12. *
  13. * FFmpeg is distributed in the hope that it will be useful,
  14. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16. * Lesser General Public License for more details.
  17. *
  18. * You should have received a copy of the GNU Lesser General Public
  19. * License along with FFmpeg; if not, write to the Free Software
  20. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21. */
  22. #ifndef AVCODEC_CELP_MATH_H
  23. #define AVCODEC_CELP_MATH_H
  24. #include <stdint.h>
  25. typedef struct CELPMContext {
  26. /**
  27. * Return the dot product.
  28. * @param a input data array
  29. * @param b input data array
  30. * @param length number of elements
  31. *
  32. * @return dot product = sum of elementwise products
  33. */
  34. float (*dot_productf)(const float* a, const float* b, int length);
  35. }CELPMContext;
  36. /**
  37. * Initialize CELPMContext.
  38. */
  39. void ff_celp_math_init(CELPMContext *c);
  40. void ff_celp_math_init_mips(CELPMContext *c);
  41. /**
  42. * fixed-point implementation of exp2(x) in [0; 1] domain.
  43. * @param power argument to exp2, 0 <= power <= 0x7fff
  44. *
  45. * @return value of (1<<20) * exp2(power / (1<<15))
  46. * 0x8000c <= result <= 0xfffea
  47. */
  48. int ff_exp2(uint16_t power);
  49. /**
  50. * Calculate log2(x).
  51. * @param value function argument, 0 < value <= 7fff ffff
  52. *
  53. * @return value of (1<<15) * log2(value)
  54. */
  55. int ff_log2_q15(uint32_t value);
  56. /**
  57. * Calculate the dot product of 2 int16_t vectors.
  58. * @param a input data array
  59. * @param b input data array
  60. * @param length number of elements
  61. *
  62. * @return dot product = sum of elementwise products
  63. */
  64. int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length);
  65. /**
  66. * Shift value left or right depending on sign of offset parameter.
  67. * @param value value to shift
  68. * @param offset shift offset
  69. *
  70. * @return value << offset, if offset>=0; value >> -offset - otherwise
  71. */
  72. static inline int bidir_sal(int value, int offset)
  73. {
  74. if(offset < 0) return value >> -offset;
  75. else return value << offset;
  76. }
  77. /**
  78. * Return the dot product.
  79. * @param a input data array
  80. * @param b input data array
  81. * @param length number of elements
  82. *
  83. * @return dot product = sum of elementwise products
  84. */
  85. float ff_dot_productf(const float* a, const float* b, int length);
  86. #endif /* AVCODEC_CELP_MATH_H */