text: /*****************************************************************************
   * cabac.h: arithmetic coder
   *****************************************************************************
   * Copyright (C) 2003-2021 x264 project
   *
   * Authors: Loren Merritt <lorenm@u.washington.edu>
   *          Laurent Aimar <fenrir@via.ecp.fr>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02111, USA.
   *
   * This program is also available under a commercial proprietary license.
   * For more information, contact us at licensing@x264.com.
   *****************************************************************************/
  
  #ifndef X264_CABAC_H
  #define X264_CABAC_H
  
  typedef struct
  {
      /* state */
      int i_low;
      int i_range;
  
      /* bit stream */
      int i_queue; //stored with an offset of -8 for faster asm
      int i_bytes_outstanding;
  
      uint8_t *p_start;
      uint8_t *p;
      uint8_t *p_end;
  
      /* aligned for memcpy_aligned starting here */
      ALIGNED_64( int f8_bits_encoded ); // only if using x264_cabac_size_decision()
  
      /* context */
      uint8_t state[1024];
  
      /* for 16-byte alignment */
      uint8_t padding[12];
  } x264_cabac_t;
  
  /* init the contexts given i_slice_type, the quantif and the model */
  #define x264_cabac_context_init x264_template(cabac_context_init)
  void x264_cabac_context_init( x264_t *h, x264_cabac_t *cb, int i_slice_type, int i_qp, int i_model );
  
  #define x264_cabac_encode_init_core x264_template(cabac_encode_init_core)
  void x264_cabac_encode_init_core( x264_cabac_t *cb );
  #define x264_cabac_encode_init x264_template(cabac_encode_init)
  void x264_cabac_encode_init( x264_cabac_t *cb, uint8_t *p_data, uint8_t *p_end );
  #define x264_cabac_encode_decision_c x264_template(cabac_encode_decision_c)
  void x264_cabac_encode_decision_c( x264_cabac_t *cb, int i_ctx, int b );
  #define x264_cabac_encode_decision_asm x264_template(cabac_encode_decision_asm)
  void x264_cabac_encode_decision_asm( x264_cabac_t *cb, int i_ctx, int b );
  #define x264_cabac_encode_bypass_c x264_template(cabac_encode_bypass_c)
  void x264_cabac_encode_bypass_c( x264_cabac_t *cb, int b );
  #define x264_cabac_encode_bypass_asm x264_template(cabac_encode_bypass_asm)
  void x264_cabac_encode_bypass_asm( x264_cabac_t *cb, int b );
  #define x264_cabac_encode_terminal_c x264_template(cabac_encode_terminal_c)
  void x264_cabac_encode_terminal_c( x264_cabac_t *cb );
  #define x264_cabac_encode_terminal_asm x264_template(cabac_encode_terminal_asm)
  void x264_cabac_encode_terminal_asm( x264_cabac_t *cb );
  #define x264_cabac_encode_ue_bypass x264_template(cabac_encode_ue_bypass)
  void x264_cabac_encode_ue_bypass( x264_cabac_t *cb, int exp_bits, int val );
  #define x264_cabac_encode_flush x264_template(cabac_encode_flush)
  void x264_cabac_encode_flush( x264_t *h, x264_cabac_t *cb );
  
  #if HAVE_MMX
  #define x264_cabac_encode_decision x264_cabac_encode_decision_asm
  #define x264_cabac_encode_bypass x264_cabac_encode_bypass_asm
  #define x264_cabac_encode_terminal x264_cabac_encode_terminal_asm
  #elif HAVE_AARCH64
  #define x264_cabac_encode_decision x264_cabac_encode_decision_asm
  #define x264_cabac_encode_bypass x264_cabac_encode_bypass_asm
  #define x264_cabac_encode_terminal x264_cabac_encode_terminal_asm
  #else
  #define x264_cabac_encode_decision x264_cabac_encode_decision_c
  #define x264_cabac_encode_bypass x264_cabac_encode_bypass_c
  #define x264_cabac_encode_terminal x264_cabac_encode_terminal_c
  #endif
  #define x264_cabac_encode_decision_noup x264_cabac_encode_decision
  
  static ALWAYS_INLINE int x264_cabac_pos( x264_cabac_t *cb )
  {
      return (cb->p - cb->p_start + cb->i_bytes_outstanding) * 8 + cb->i_queue;
  }
  
  /* internal only. these don't write the bitstream, just calculate bit cost: */
  
  static ALWAYS_INLINE void x264_cabac_size_decision( x264_cabac_t *cb, long i_ctx, long b )
  {
      int i_state = cb->state[i_ctx];
      cb->state[i_ctx] = x264_cabac_transition[i_state][b];
      cb->f8_bits_encoded += x264_cabac_entropy[i_state^b];
  }
  
  static ALWAYS_INLINE int x264_cabac_size_decision2( uint8_t *state, long b )
  {
      int i_state = *state;
      *state = x264_cabac_transition[i_state][b];
      return x264_cabac_entropy[i_state^b];
  }
  
  static ALWAYS_INLINE void x264_cabac_size_decision_noup( x264_cabac_t *cb, long i_ctx, long b )
  {
      int i_state = cb->state[i_ctx];
      cb->f8_bits_encoded += x264_cabac_entropy[i_state^b];
  }
  
  static ALWAYS_INLINE int x264_cabac_size_decision_noup2( uint8_t *state, long b )
  {
      return x264_cabac_entropy[*state^b];
  }
  
  #endif
  