atrac.h 3.3 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394959697
  1. /*
  2. * common functions for the ATRAC family of decoders
  3. *
  4. * Copyright (c) 2009-2013 Maxim Poliakovski
  5. * Copyright (c) 2009 Benjamin Larsson
  6. *
  7. * This file is part of FFmpeg.
  8. *
  9. * FFmpeg is free software; you can redistribute it and/or
  10. * modify it under the terms of the GNU Lesser General Public
  11. * License as published by the Free Software Foundation; either
  12. * version 2.1 of the License, or (at your option) any later version.
  13. *
  14. * FFmpeg is distributed in the hope that it will be useful,
  15. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17. * Lesser General Public License for more details.
  18. *
  19. * You should have received a copy of the GNU Lesser General Public
  20. * License along with FFmpeg; if not, write to the Free Software
  21. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22. */
  23. /**
  24. * @file
  25. * ATRAC common header
  26. */
  27. #ifndef AVCODEC_ATRAC_H
  28. #define AVCODEC_ATRAC_H
  29. /**
  30. * Gain control parameters for one subband.
  31. */
  32. typedef struct AtracGainInfo {
  33. int num_points; ///< number of gain control points
  34. int lev_code[7]; ///< level at corresponding control point
  35. int loc_code[7]; ///< location of gain control points
  36. } AtracGainInfo;
  37. /**
  38. * Gain compensation context structure.
  39. */
  40. typedef struct AtracGCContext {
  41. float gain_tab1[16]; ///< gain compensation level table
  42. float gain_tab2[31]; ///< gain compensation interpolation table
  43. int id2exp_offset; ///< offset for converting level index into level exponent
  44. int loc_scale; ///< scale of location code = 2^loc_scale samples
  45. int loc_size; ///< size of location code in samples
  46. } AtracGCContext;
  47. extern float ff_atrac_sf_table[64];
  48. /**
  49. * Generate common tables.
  50. */
  51. void ff_atrac_generate_tables(void);
  52. /**
  53. * Initialize gain compensation context.
  54. *
  55. * @param gctx pointer to gain compensation context to initialize
  56. * @param id2exp_offset offset for converting level index into level exponent
  57. * @param loc_scale location size factor
  58. */
  59. void ff_atrac_init_gain_compensation(AtracGCContext *gctx, int id2exp_offset,
  60. int loc_scale);
  61. /**
  62. * Apply gain compensation and perform the MDCT overlapping part.
  63. *
  64. * @param gctx pointer to gain compensation context
  65. * @param in input buffer
  66. * @param prev previous buffer to perform overlap against
  67. * @param gc_now gain control information for current frame
  68. * @param gc_next gain control information for next frame
  69. * @param num_samples number of samples to process
  70. * @param out output data goes here
  71. */
  72. void ff_atrac_gain_compensation(AtracGCContext *gctx, float *in, float *prev,
  73. AtracGainInfo *gc_now, AtracGainInfo *gc_next,
  74. int num_samples, float *out);
  75. /**
  76. * Quadrature mirror synthesis filter.
  77. *
  78. * @param inlo lower part of spectrum
  79. * @param inhi higher part of spectrum
  80. * @param nIn size of spectrum buffer
  81. * @param pOut out buffer
  82. * @param delayBuf delayBuf buffer
  83. * @param temp temp buffer
  84. */
  85. void ff_atrac_iqmf(float *inlo, float *inhi, unsigned int nIn, float *pOut,
  86. float *delayBuf, float *temp);
  87. #endif /* AVCODEC_ATRAC_H */