cabac.h 1.7 KB

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  1. /*
  2. * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
  3. * Copyright (c) 2003 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. * Context Adaptive Binary Arithmetic Coder.
  24. */
  25. #ifndef AVCODEC_CABAC_H
  26. #define AVCODEC_CABAC_H
  27. #include <stdint.h>
  28. #include "put_bits.h"
  29. extern const uint8_t ff_h264_cabac_tables[512 + 4*2*64 + 4*64 + 63];
  30. #define H264_NORM_SHIFT_OFFSET 0
  31. #define H264_LPS_RANGE_OFFSET 512
  32. #define H264_MLPS_STATE_OFFSET 1024
  33. #define H264_LAST_COEFF_FLAG_OFFSET_8x8_OFFSET 1280
  34. #define CABAC_BITS 16
  35. #define CABAC_MASK ((1<<CABAC_BITS)-1)
  36. typedef struct CABACContext{
  37. int low;
  38. int range;
  39. int outstanding_count;
  40. const uint8_t *bytestream_start;
  41. const uint8_t *bytestream;
  42. const uint8_t *bytestream_end;
  43. PutBitContext pb;
  44. }CABACContext;
  45. void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size);
  46. int ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size);
  47. #endif /* AVCODEC_CABAC_H */