cbrt_tablegen.h 2.2 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273
  1. /*
  2. * Header file for hardcoded AAC cube-root table
  3. *
  4. * Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
  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_CBRT_TABLEGEN_H
  23. #define AVCODEC_CBRT_TABLEGEN_H
  24. #include <stdint.h>
  25. #include <math.h>
  26. #include "libavutil/attributes.h"
  27. #include "libavutil/intfloat.h"
  28. #include "libavcodec/aac_defines.h"
  29. #if USE_FIXED
  30. #define CBRT(x) lrint((x) * 8192)
  31. #else
  32. #define CBRT(x) av_float2int((float)(x))
  33. #endif
  34. uint32_t AAC_RENAME(ff_cbrt_tab)[1 << 13];
  35. av_cold void AAC_RENAME(ff_cbrt_tableinit)(void)
  36. {
  37. static double cbrt_tab_dbl[1 << 13];
  38. if (!AAC_RENAME(ff_cbrt_tab)[(1<<13) - 1]) {
  39. int i, j, k;
  40. double cbrt_val;
  41. for (i = 1; i < 1<<13; i++)
  42. cbrt_tab_dbl[i] = 1;
  43. /* have to take care of non-squarefree numbers */
  44. for (i = 2; i < 90; i++) {
  45. if (cbrt_tab_dbl[i] == 1) {
  46. cbrt_val = i * cbrt(i);
  47. for (k = i; k < 1<<13; k *= i)
  48. for (j = k; j < 1<<13; j += k)
  49. cbrt_tab_dbl[j] *= cbrt_val;
  50. }
  51. }
  52. for (i = 91; i <= 8191; i+= 2) {
  53. if (cbrt_tab_dbl[i] == 1) {
  54. cbrt_val = i * cbrt(i);
  55. for (j = i; j < 1<<13; j += i)
  56. cbrt_tab_dbl[j] *= cbrt_val;
  57. }
  58. }
  59. for (i = 0; i < 1<<13; i++)
  60. AAC_RENAME(ff_cbrt_tab)[i] = CBRT(cbrt_tab_dbl[i]);
  61. }
  62. }
  63. #endif /* AVCODEC_CBRT_TABLEGEN_H */