aom/av1/common/txb_common.h

305 строки
8.0 KiB
C

/*
* 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_
extern const int16_t av1_coeff_band_4x4[16];
extern const int16_t av1_coeff_band_8x8[64];
extern const int16_t av1_coeff_band_16x16[256];
extern const int16_t av1_coeff_band_32x32[1024];
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;
assert(5 + ctx <= 7);
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;
assert(ctx < 3);
return 8 + ctx;
}
if (col == 0) {
ctx = (ctx + 1) >> 1;
assert(ctx < 3);
return 11 + ctx;
}
ctx >>= 1;
assert(14 + ctx < 20);
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 av1_coeff_band_4x4[c];
if (bwl == 3) return av1_coeff_band_8x8[c];
if (bwl == 4) return av1_coeff_band_16x16[c];
if (bwl == 5) return av1_coeff_band_32x32[c];
assert(0);
return 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;
}
static INLINE int get_dc_sign_ctx(int dc_sign) {
int dc_sign_ctx = 0;
if (dc_sign < 0)
dc_sign_ctx = 1;
else if (dc_sign > 0)
dc_sign_ctx = 2;
return dc_sign_ctx;
}
static INLINE void get_txb_ctx(BLOCK_SIZE plane_bsize, TX_SIZE tx_size,
int plane, const ENTROPY_CONTEXT *a,
const ENTROPY_CONTEXT *l, TXB_CTX *txb_ctx) {
const int tx_size_in_blocks = 1 << tx_size;
int ctx_offset = (plane == 0) ? 0 : 7;
int k;
if (plane_bsize > txsize_to_bsize[tx_size]) ctx_offset += 3;
int dc_sign = 0;
for (k = 0; k < tx_size_in_blocks; ++k) {
int sign = ((uint8_t)a[k]) >> COEFF_CONTEXT_BITS;
if (sign == 1)
--dc_sign;
else if (sign == 2)
++dc_sign;
else if (sign != 0)
assert(0);
sign = ((uint8_t)l[k]) >> COEFF_CONTEXT_BITS;
if (sign == 1)
--dc_sign;
else if (sign == 2)
++dc_sign;
else if (sign != 0)
assert(0);
}
txb_ctx->dc_sign_ctx = get_dc_sign_ctx(dc_sign);
if (plane == 0) {
int top = 0;
int left = 0;
for (k = 0; k < tx_size_in_blocks; ++k) {
top = AOMMAX(top, ((uint8_t)a[k] & COEFF_CONTEXT_MASK));
left = AOMMAX(left, ((uint8_t)l[k] & COEFF_CONTEXT_MASK));
}
top = AOMMIN(top, 255);
left = AOMMIN(left, 255);
if (plane_bsize == txsize_to_bsize[tx_size])
txb_ctx->txb_skip_ctx = 0;
else if (top == 0 && left == 0)
txb_ctx->txb_skip_ctx = 1;
else if (top == 0 || left == 0)
txb_ctx->txb_skip_ctx = 2 + (AOMMAX(top, left) > 3);
else if (AOMMAX(top, left) <= 3)
txb_ctx->txb_skip_ctx = 4;
else if (AOMMIN(top, left) <= 3)
txb_ctx->txb_skip_ctx = 5;
else
txb_ctx->txb_skip_ctx = 6;
} else {
int ctx_base = get_entropy_context(tx_size, a, l);
txb_ctx->txb_skip_ctx = ctx_offset + ctx_base;
}
}
void av1_adapt_txb_probs(AV1_COMMON *cm, unsigned int count_sat,
unsigned int update_factor);
#endif // AV1_COMMON_TXB_COMMON_H_