av1/common/txb_common.h - avm - Git at Google

 /*
  * Copyright (c) 2017, Alliance for Open Media. All rights reserved
  *
  * This source code is subject to the terms of the BSD 2 Clause License and
  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
  * was not distributed with this source code in the LICENSE file, you can
  * obtain it at www.aomedia.org/license/software. If the Alliance for Open
  * Media Patent License 1.0 was not distributed with this source code in the
  * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
  */

 #ifndef AV1_COMMON_TXB_COMMON_H_
 #define AV1_COMMON_TXB_COMMON_H_
 static int16_t coeff_band_4x4[16] = { 0, 1, 2,  3,  4,  5,  6,  7,
                                       8, 9, 10, 11, 12, 13, 14, 15 };

 static int16_t coeff_band_8x8[64] = {
   0,  1,  2,  2,  3,  3,  4,  4,  5,  6,  2,  2,  3,  3,  4,  4,
   7,  7,  8,  8,  9,  9,  10, 10, 7,  7,  8,  8,  9,  9,  10, 10,
   11, 11, 12, 12, 13, 13, 14, 14, 11, 11, 12, 12, 13, 13, 14, 14,
   15, 15, 16, 16, 17, 17, 18, 18, 15, 15, 16, 16, 17, 17, 18, 18,
 };

 static int16_t coeff_band_16x16[256] = {
   0,  1,  4,  4,  7,  7,  7,  7,  8,  8,  8,  8,  9,  9,  9,  9,  2,  3,  4,
   4,  7,  7,  7,  7,  8,  8,  8,  8,  9,  9,  9,  9,  5,  5,  6,  6,  7,  7,
   7,  7,  8,  8,  8,  8,  9,  9,  9,  9,  5,  5,  6,  6,  7,  7,  7,  7,  8,
   8,  8,  8,  9,  9,  9,  9,  10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12,
   13, 13, 13, 13, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13,
   13, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 10, 10,
   10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 14, 15,
   15, 15, 15, 16, 16, 16, 16, 17, 17, 17, 17, 14, 14, 14, 14, 15, 15, 15, 15,
   16, 16, 16, 16, 17, 17, 17, 17, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16,
   16, 17, 17, 17, 17, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17, 17,
   17, 17, 18, 18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 18,
   18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 18, 18, 18, 18,
   19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 18, 18, 18, 18, 19, 19, 19,
   19, 20, 20, 20, 20, 21, 21, 21, 21,
 };

 static int16_t coeff_band_32x32[1024] = {
   0,  1,  4,  4,  7,  7,  7,  7,  10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11,
   11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 2,  3,  4,  4,  7,  7,
   7,  7,  10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 12,
   12, 12, 12, 12, 12, 12, 12, 5,  5,  6,  6,  7,  7,  7,  7,  10, 10, 10, 10,
   10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12,
   12, 5,  5,  6,  6,  7,  7,  7,  7,  10, 10, 10, 10, 10, 10, 10, 10, 11, 11,
   11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 8,  8,  8,  8,  9,
   9,  9,  9,  10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11,
   12, 12, 12, 12, 12, 12, 12, 12, 8,  8,  8,  8,  9,  9,  9,  9,  10, 10, 10,
   10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12,
   12, 12, 8,  8,  8,  8,  9,  9,  9,  9,  10, 10, 10, 10, 10, 10, 10, 10, 11,
   11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 8,  8,  8,  8,
   9,  9,  9,  9,  10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11,
   11, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14,
   14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16,
   16, 16, 16, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14,
   15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 13, 13, 13,
   13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15,
   15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 13, 13, 13, 13, 13, 13, 13, 13, 14,
   14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16,
   16, 16, 16, 16, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14,
   14, 15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 13, 13,
   13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15,
   15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 13, 13, 13, 13, 13, 13, 13, 13,
   14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16,
   16, 16, 16, 16, 16, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14,
   14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 17,
   17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
   19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 17, 17, 17, 17, 17, 17, 17,
   17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20,
   20, 20, 20, 20, 20, 20, 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18,
   18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20,
   17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19,
   19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 17, 17, 17, 17, 17, 17,
   17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 20,
   20, 20, 20, 20, 20, 20, 20, 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18,
   18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20,
   20, 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19,
   19, 19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 17, 17, 17, 17, 17,
   17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19,
   20, 20, 20, 20, 20, 20, 20, 20, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22,
   22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24,
   24, 24, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22, 23,
   23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 21, 21, 21, 21,
   21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23,
   23, 24, 24, 24, 24, 24, 24, 24, 24, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22,
   22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24,
   24, 24, 24, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22,
   23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 21, 21, 21,
   21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23,
   23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 21, 21, 21, 21, 21, 21, 21, 21, 22,
   22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24,
   24, 24, 24, 24, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22,
   22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24,
 };

 typedef struct txb_ctx {
   int txb_skip_ctx;
   int dc_sign_ctx;
 } TXB_CTX;

 #define BASE_CONTEXT_POSITION_NUM 12
 static int base_ref_offset[BASE_CONTEXT_POSITION_NUM][2] = {
   /* clang-format off*/
   { -2, 0 }, { -1, -1 }, { -1, 0 }, { -1, 1 }, { 0, -2 }, { 0, -1 }, { 0, 1 },
   { 0, 2 },  { 1, -1 },  { 1, 0 },  { 1, 1 },  { 2, 0 }
   /* clang-format on*/
 };

 static INLINE int get_base_ctx(const tran_low_t *tcoeffs,
                                int c,  // raster order
                                const int bwl, const int level) {
   const int row = c >> bwl;
   const int col = c - (row << bwl);
   const int stride = 1 << bwl;
   const int level_minus_1 = level - 1;
   int ctx = 0;
   int mag = 0;
   int idx;
   int ctx_idx = -1;
   tran_low_t abs_coeff;

   ctx = 0;
   for (idx = 0; idx < BASE_CONTEXT_POSITION_NUM; ++idx) {
     int ref_row = row + base_ref_offset[idx][0];
     int ref_col = col + base_ref_offset[idx][1];
     int pos = (ref_row << bwl) + ref_col;

     if (ref_row < 0 || ref_col < 0 || ref_row >= stride || ref_col >= stride)
       continue;

     abs_coeff = abs(tcoeffs[pos]);
     ctx += abs_coeff > level_minus_1;

     if (base_ref_offset[idx][0] >= 0 && base_ref_offset[idx][1] >= 0)
       mag |= abs_coeff > level;
   }
   ctx = (ctx + 1) >> 1;
   if (row == 0 && col == 0) {
     ctx_idx = (ctx << 1) + mag;
     assert(ctx_idx < 8);
   } else if (row == 0) {
     ctx_idx = 8 + (ctx << 1) + mag;
     assert(ctx_idx < 18);
   } else if (col == 0) {
     ctx_idx = 8 + 10 + (ctx << 1) + mag;
     assert(ctx_idx < 28);
   } else {
     ctx_idx = 8 + 10 + 10 + (ctx << 1) + mag;
     assert(ctx_idx < COEFF_BASE_CONTEXTS);
   }
   return ctx_idx;
 }

 #define BR_CONTEXT_POSITION_NUM 8  // Base range coefficient context
 static int br_ref_offset[BR_CONTEXT_POSITION_NUM][2] = {
   /* clang-format off*/
   { -1, -1 }, { -1, 0 }, { -1, 1 }, { 0, -1 },
   { 0, 1 },   { 1, -1 }, { 1, 0 },  { 1, 1 },
   /* clang-format on*/
 };

 static int br_level_map[9] = {
   0, 0, 1, 1, 2, 2, 3, 3, 3,
 };

 static INLINE int get_level_ctx(const tran_low_t *tcoeffs,
                                 const int c,  // raster order
                                 const int bwl) {
   const int row = c >> bwl;
   const int col = c - (row << bwl);
   const int stride = 1 << bwl;
   const int level_minus_1 = NUM_BASE_LEVELS;
   int ctx = 0;
   int idx;
   tran_low_t abs_coeff;
   int mag = 0, offset = 0;

   for (idx = 0; idx < BR_CONTEXT_POSITION_NUM; ++idx) {
     int ref_row = row + br_ref_offset[idx][0];
     int ref_col = col + br_ref_offset[idx][1];
     int pos = (ref_row << bwl) + ref_col;

     if (ref_row < 0 || ref_col < 0 || ref_row >= stride || ref_col >= stride)
       continue;

     abs_coeff = abs(tcoeffs[pos]);
     ctx += abs_coeff > level_minus_1;

     if (br_ref_offset[idx][0] >= 0 && br_ref_offset[idx][1] >= 0)
       mag = AOMMAX(mag, abs_coeff);
   }

   if (mag <= 1)
     offset = 0;
   else if (mag <= 3)
     offset = 1;
   else if (mag <= 6)
     offset = 2;
   else
     offset = 3;

   ctx = br_level_map[ctx];

   ctx += offset * BR_TMP_OFFSET;

   // DC: 0 - 1
   if (row == 0 && col == 0) return ctx;

   // Top row: 2 - 4
   if (row == 0) return 2 + ctx;

   // Left column: 5 - 7
   if (col == 0) return 5 + ctx;

   // others: 8 - 11
   return 8 + ctx;
 }

 static int sig_ref_offset[11][2] = {
   { -2, -1 }, { -2, 0 }, { -2, 1 }, { -1, -2 }, { -1, -1 }, { -1, 0 },
   { -1, 1 },  { 0, -2 }, { 0, -1 }, { 1, -2 },  { 1, -1 },
 };

 static INLINE int get_nz_map_ctx(const tran_low_t *tcoeffs,
                                  const uint8_t *txb_mask,
                                  const int c,  // raster order
                                  const int bwl) {
   const int row = c >> bwl;
   const int col = c - (row << bwl);
   int ctx = 0;
   int idx;
   int stride = 1 << bwl;

   if (row == 0 && col == 0) return 0;

   if (row == 0 && col == 1) return 1 + (tcoeffs[0] != 0);

   if (row == 1 && col == 0) return 3 + (tcoeffs[0] != 0);

   if (row == 1 && col == 1) {
     int pos;
     ctx = (tcoeffs[0] != 0);

     if (txb_mask[1]) ctx += (tcoeffs[1] != 0);
     pos = 1 << bwl;
     if (txb_mask[pos]) ctx += (tcoeffs[pos] != 0);

     ctx = (ctx + 1) >> 1;

     // unit test purpose
     if (5 + ctx > 7) exit(0);

     return 5 + ctx;
   }

   for (idx = 0; idx < 11; ++idx) {
     int ref_row = row + sig_ref_offset[idx][0];
     int ref_col = col + sig_ref_offset[idx][1];
     int pos;

     if (ref_row < 0 || ref_col < 0 || ref_row >= stride || ref_col >= stride)
       continue;

     pos = (ref_row << bwl) + ref_col;

     if (txb_mask[pos]) ctx += (tcoeffs[pos] != 0);
   }

   if (row == 0) {
     ctx = (ctx + 1) >> 1;

     if (ctx >= 3) exit(0);
     return 8 + ctx;
   }

   if (col == 0) {
     ctx = (ctx + 1) >> 1;

     if (ctx >= 3) exit(0);
     return 11 + ctx;
   }

   ctx >>= 1;

   if (14 + ctx >= 20) exit(0);

   return 14 + ctx;
 }

 static INLINE int get_eob_ctx(const tran_low_t *tcoeffs,
                               const int c,  // raster order
                               const int bwl) {
   (void)tcoeffs;
   if (bwl == 2) return coeff_band_4x4[c];
   if (bwl == 3) return coeff_band_8x8[c];
   if (bwl == 4) return coeff_band_16x16[c];
   if (bwl == 5) return coeff_band_32x32[c];

   exit(0);
 }

 static INLINE void set_dc_sign(int *cul_level, tran_low_t v) {
   if (v < 0)
     *cul_level |= 1 << COEFF_CONTEXT_BITS;
   else if (v > 0)
     *cul_level += 2 << COEFF_CONTEXT_BITS;
 }
 #endif  // AV1_COMMON_TXB_COMMON_H_
	/*
	* Copyright (c) 2017, Alliance for Open Media. All rights reserved
	*
	* This source code is subject to the terms of the BSD 2 Clause License and
	* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
	* was not distributed with this source code in the LICENSE file, you can
	* obtain it at www.aomedia.org/license/software. If the Alliance for Open
	* Media Patent License 1.0 was not distributed with this source code in the
	* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
	*/

	#ifndef AV1_COMMON_TXB_COMMON_H_
	#define AV1_COMMON_TXB_COMMON_H_
	static int16_t coeff_band_4x4[16] = { 0, 1, 2, 3, 4, 5, 6, 7,
	8, 9, 10, 11, 12, 13, 14, 15 };

	static int16_t coeff_band_8x8[64] = {
	0, 1, 2, 2, 3, 3, 4, 4, 5, 6, 2, 2, 3, 3, 4, 4,
	7, 7, 8, 8, 9, 9, 10, 10, 7, 7, 8, 8, 9, 9, 10, 10,
	11, 11, 12, 12, 13, 13, 14, 14, 11, 11, 12, 12, 13, 13, 14, 14,
	15, 15, 16, 16, 17, 17, 18, 18, 15, 15, 16, 16, 17, 17, 18, 18,
	};

	static int16_t coeff_band_16x16[256] = {
	0, 1, 4, 4, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 2, 3, 4,
	4, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 5, 5, 6, 6, 7, 7,
	7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 5, 5, 6, 6, 7, 7, 7, 7, 8,
	8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12,
	13, 13, 13, 13, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13,
	13, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 10, 10,
	10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 14, 15,
	15, 15, 15, 16, 16, 16, 16, 17, 17, 17, 17, 14, 14, 14, 14, 15, 15, 15, 15,
	16, 16, 16, 16, 17, 17, 17, 17, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16,
	16, 17, 17, 17, 17, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17, 17,
	17, 17, 18, 18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 18,
	18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 18, 18, 18, 18,
	19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 18, 18, 18, 18, 19, 19, 19,
	19, 20, 20, 20, 20, 21, 21, 21, 21,
	};

	static int16_t coeff_band_32x32[1024] = {
	0, 1, 4, 4, 7, 7, 7, 7, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11,
	11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 2, 3, 4, 4, 7, 7,
	7, 7, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 12,
	12, 12, 12, 12, 12, 12, 12, 5, 5, 6, 6, 7, 7, 7, 7, 10, 10, 10, 10,
	10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12,
	12, 5, 5, 6, 6, 7, 7, 7, 7, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11,
	11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 8, 8, 8, 8, 9,
	9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11,
	12, 12, 12, 12, 12, 12, 12, 12, 8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10,
	10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12,
	12, 12, 8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 11,
	11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 8, 8, 8, 8,
	9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11,
	11, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14,
	14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16,
	16, 16, 16, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14,
	15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 13, 13, 13,
	13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15,
	15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 13, 13, 13, 13, 13, 13, 13, 13, 14,
	14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16,
	16, 16, 16, 16, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14,
	14, 15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 13, 13,
	13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15,
	15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 13, 13, 13, 13, 13, 13, 13, 13,
	14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16,
	16, 16, 16, 16, 16, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14,
	14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 17,
	17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
	19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 17, 17, 17, 17, 17, 17, 17,
	17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20,
	20, 20, 20, 20, 20, 20, 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18,
	18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20,
	17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19,
	19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 17, 17, 17, 17, 17, 17,
	17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 20,
	20, 20, 20, 20, 20, 20, 20, 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18,
	18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20,
	20, 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19,
	19, 19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 17, 17, 17, 17, 17,
	17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19,
	20, 20, 20, 20, 20, 20, 20, 20, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22,
	22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24,
	24, 24, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22, 23,
	23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 21, 21, 21, 21,
	21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23,
	23, 24, 24, 24, 24, 24, 24, 24, 24, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22,
	22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24,
	24, 24, 24, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22,
	23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 21, 21, 21,
	21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23,
	23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 21, 21, 21, 21, 21, 21, 21, 21, 22,
	22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24,
	24, 24, 24, 24, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22,
	22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24,
	};

	typedef struct txb_ctx {
	int txb_skip_ctx;
	int dc_sign_ctx;
	} TXB_CTX;

	#define BASE_CONTEXT_POSITION_NUM 12
	static int base_ref_offset[BASE_CONTEXT_POSITION_NUM][2] = {
	/* clang-format off*/
	{ -2, 0 }, { -1, -1 }, { -1, 0 }, { -1, 1 }, { 0, -2 }, { 0, -1 }, { 0, 1 },
	{ 0, 2 }, { 1, -1 }, { 1, 0 }, { 1, 1 }, { 2, 0 }
	/* clang-format on*/
	};

	static INLINE int get_base_ctx(const tran_low_t *tcoeffs,
	int c, // raster order
	const int bwl, const int level) {
	const int row = c >> bwl;
	const int col = c - (row << bwl);
	const int stride = 1 << bwl;
	const int level_minus_1 = level - 1;
	int ctx = 0;
	int mag = 0;
	int idx;
	int ctx_idx = -1;
	tran_low_t abs_coeff;

	ctx = 0;
	for (idx = 0; idx < BASE_CONTEXT_POSITION_NUM; ++idx) {
	int ref_row = row + base_ref_offset[idx][0];
	int ref_col = col + base_ref_offset[idx][1];
	int pos = (ref_row << bwl) + ref_col;

	if (ref_row < 0 \|\| ref_col < 0 \|\| ref_row >= stride \|\| ref_col >= stride)
	continue;

	abs_coeff = abs(tcoeffs[pos]);
	ctx += abs_coeff > level_minus_1;

	if (base_ref_offset[idx][0] >= 0 && base_ref_offset[idx][1] >= 0)
	mag \|= abs_coeff > level;
	}
	ctx = (ctx + 1) >> 1;
	if (row == 0 && col == 0) {
	ctx_idx = (ctx << 1) + mag;
	assert(ctx_idx < 8);
	} else if (row == 0) {
	ctx_idx = 8 + (ctx << 1) + mag;
	assert(ctx_idx < 18);
	} else if (col == 0) {
	ctx_idx = 8 + 10 + (ctx << 1) + mag;
	assert(ctx_idx < 28);
	} else {
	ctx_idx = 8 + 10 + 10 + (ctx << 1) + mag;
	assert(ctx_idx < COEFF_BASE_CONTEXTS);
	}
	return ctx_idx;
	}

	#define BR_CONTEXT_POSITION_NUM 8 // Base range coefficient context
	static int br_ref_offset[BR_CONTEXT_POSITION_NUM][2] = {
	/* clang-format off*/
	{ -1, -1 }, { -1, 0 }, { -1, 1 }, { 0, -1 },
	{ 0, 1 }, { 1, -1 }, { 1, 0 }, { 1, 1 },
	/* clang-format on*/
	};

	static int br_level_map[9] = {
	0, 0, 1, 1, 2, 2, 3, 3, 3,
	};

	static INLINE int get_level_ctx(const tran_low_t *tcoeffs,
	const int c, // raster order
	const int bwl) {
	const int row = c >> bwl;
	const int col = c - (row << bwl);
	const int stride = 1 << bwl;
	const int level_minus_1 = NUM_BASE_LEVELS;
	int ctx = 0;
	int idx;
	tran_low_t abs_coeff;
	int mag = 0, offset = 0;

	for (idx = 0; idx < BR_CONTEXT_POSITION_NUM; ++idx) {
	int ref_row = row + br_ref_offset[idx][0];
	int ref_col = col + br_ref_offset[idx][1];
	int pos = (ref_row << bwl) + ref_col;

	if (ref_row < 0 \|\| ref_col < 0 \|\| ref_row >= stride \|\| ref_col >= stride)
	continue;

	abs_coeff = abs(tcoeffs[pos]);
	ctx += abs_coeff > level_minus_1;

	if (br_ref_offset[idx][0] >= 0 && br_ref_offset[idx][1] >= 0)
	mag = AOMMAX(mag, abs_coeff);
	}

	if (mag <= 1)
	offset = 0;
	else if (mag <= 3)
	offset = 1;
	else if (mag <= 6)
	offset = 2;
	else
	offset = 3;

	ctx = br_level_map[ctx];

	ctx += offset * BR_TMP_OFFSET;

	// DC: 0 - 1
	if (row == 0 && col == 0) return ctx;

	// Top row: 2 - 4
	if (row == 0) return 2 + ctx;

	// Left column: 5 - 7
	if (col == 0) return 5 + ctx;

	// others: 8 - 11
	return 8 + ctx;
	}

	static int sig_ref_offset[11][2] = {
	{ -2, -1 }, { -2, 0 }, { -2, 1 }, { -1, -2 }, { -1, -1 }, { -1, 0 },
	{ -1, 1 }, { 0, -2 }, { 0, -1 }, { 1, -2 }, { 1, -1 },
	};

	static INLINE int get_nz_map_ctx(const tran_low_t *tcoeffs,
	const uint8_t *txb_mask,
	const int c, // raster order
	const int bwl) {
	const int row = c >> bwl;
	const int col = c - (row << bwl);
	int ctx = 0;
	int idx;
	int stride = 1 << bwl;

	if (row == 0 && col == 0) return 0;

	if (row == 0 && col == 1) return 1 + (tcoeffs[0] != 0);

	if (row == 1 && col == 0) return 3 + (tcoeffs[0] != 0);

	if (row == 1 && col == 1) {
	int pos;
	ctx = (tcoeffs[0] != 0);

	if (txb_mask[1]) ctx += (tcoeffs[1] != 0);
	pos = 1 << bwl;
	if (txb_mask[pos]) ctx += (tcoeffs[pos] != 0);

	ctx = (ctx + 1) >> 1;

	// unit test purpose
	if (5 + ctx > 7) exit(0);

	return 5 + ctx;
	}

	for (idx = 0; idx < 11; ++idx) {
	int ref_row = row + sig_ref_offset[idx][0];
	int ref_col = col + sig_ref_offset[idx][1];
	int pos;

	if (ref_row < 0 \|\| ref_col < 0 \|\| ref_row >= stride \|\| ref_col >= stride)
	continue;

	pos = (ref_row << bwl) + ref_col;

	if (txb_mask[pos]) ctx += (tcoeffs[pos] != 0);
	}

	if (row == 0) {
	ctx = (ctx + 1) >> 1;

	if (ctx >= 3) exit(0);
	return 8 + ctx;
	}

	if (col == 0) {
	ctx = (ctx + 1) >> 1;

	if (ctx >= 3) exit(0);
	return 11 + ctx;
	}

	ctx >>= 1;

	if (14 + ctx >= 20) exit(0);

	return 14 + ctx;
	}

	static INLINE int get_eob_ctx(const tran_low_t *tcoeffs,
	const int c, // raster order
	const int bwl) {
	(void)tcoeffs;
	if (bwl == 2) return coeff_band_4x4[c];
	if (bwl == 3) return coeff_band_8x8[c];
	if (bwl == 4) return coeff_band_16x16[c];
	if (bwl == 5) return coeff_band_32x32[c];

	exit(0);
	}

	static INLINE void set_dc_sign(int *cul_level, tran_low_t v) {
	if (v < 0)
	*cul_level \|= 1 << COEFF_CONTEXT_BITS;
	else if (v > 0)
	*cul_level += 2 << COEFF_CONTEXT_BITS;
	}
	#endif // AV1_COMMON_TXB_COMMON_H_