elsdec.h 1.7 KB

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  1. /*
  2. * ELS (Entropy Logarithmic-Scale) decoder
  3. *
  4. * Copyright (c) 2013 Maxim Poliakovski
  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. /**
  23. * @file
  24. * Entropy Logarithmic-Scale binary arithmetic coder
  25. */
  26. #ifndef AVCODEC_ELSDEC_H
  27. #define AVCODEC_ELSDEC_H
  28. #include <stdint.h>
  29. #include <sys/types.h>
  30. #define ELS_EXPGOLOMB_LEN 10
  31. typedef struct ElsDecCtx {
  32. const uint8_t *in_buf;
  33. unsigned x;
  34. size_t data_size;
  35. int j, t, diff, err;
  36. } ElsDecCtx;
  37. typedef struct ElsRungNode {
  38. uint8_t rung;
  39. uint16_t next_index;
  40. } ElsRungNode;
  41. typedef struct ElsUnsignedRung {
  42. uint8_t prefix_rung[ELS_EXPGOLOMB_LEN + 1];
  43. ElsRungNode *rem_rung_list;
  44. size_t rung_list_size;
  45. uint16_t avail_index;
  46. } ElsUnsignedRung;
  47. void ff_els_decoder_init(ElsDecCtx *ctx, const uint8_t *in, size_t data_size);
  48. void ff_els_decoder_uninit(ElsUnsignedRung *rung);
  49. int ff_els_decode_bit(ElsDecCtx *ctx, unsigned char *rung);
  50. unsigned ff_els_decode_unsigned(ElsDecCtx *ctx, ElsUnsignedRung *ur);
  51. #endif /* AVCODEC_ELSDEC_H */