| /* |
| * Copyright (c) 2016, 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. |
| */ |
| #include "aom_dsp/bitwriter.h" |
| |
| #include "av1/common/common.h" |
| #include "av1/common/entropy.h" |
| #include "av1/encoder/cost.h" |
| #include "av1/encoder/subexp.h" |
| |
| static const uint8_t update_bits[255] = { |
| 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, |
| 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 8, 8, 8, 8, 8, 8, |
| 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, |
| 8, 8, 8, 8, 8, 8, 8, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, |
| 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, |
| 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, |
| 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, |
| 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, |
| 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, |
| 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, |
| 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, |
| 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, |
| 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, |
| 11, 11, 11, 11, 11, 11, 11, 0, |
| }; |
| #define MIN_DELP_BITS 5 |
| |
| static int recenter_nonneg(int v, int m) { |
| if (v > (m << 1)) |
| return v; |
| else if (v >= m) |
| return ((v - m) << 1); |
| else |
| return ((m - v) << 1) - 1; |
| } |
| |
| static int remap_prob(int v, int m) { |
| int i; |
| static const uint8_t map_table[MAX_PROB - 1] = { |
| // generated by: |
| // map_table[j] = split_index(j, MAX_PROB - 1, MODULUS_PARAM); |
| 20, 21, 22, 23, 24, 25, 0, 26, 27, 28, 29, 30, 31, 32, 33, |
| 34, 35, 36, 37, 1, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, |
| 48, 49, 2, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, |
| 3, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 4, 74, |
| 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 5, 86, 87, 88, |
| 89, 90, 91, 92, 93, 94, 95, 96, 97, 6, 98, 99, 100, 101, 102, |
| 103, 104, 105, 106, 107, 108, 109, 7, 110, 111, 112, 113, 114, 115, 116, |
| 117, 118, 119, 120, 121, 8, 122, 123, 124, 125, 126, 127, 128, 129, 130, |
| 131, 132, 133, 9, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, |
| 145, 10, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 11, |
| 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 12, 170, 171, |
| 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 13, 182, 183, 184, 185, |
| 186, 187, 188, 189, 190, 191, 192, 193, 14, 194, 195, 196, 197, 198, 199, |
| 200, 201, 202, 203, 204, 205, 15, 206, 207, 208, 209, 210, 211, 212, 213, |
| 214, 215, 216, 217, 16, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, |
| 228, 229, 17, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, |
| 18, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 19, |
| }; |
| v--; |
| m--; |
| if ((m << 1) <= MAX_PROB) |
| i = recenter_nonneg(v, m) - 1; |
| else |
| i = recenter_nonneg(MAX_PROB - 1 - v, MAX_PROB - 1 - m) - 1; |
| |
| i = map_table[i]; |
| return i; |
| } |
| |
| static int prob_diff_update_cost(aom_prob newp, aom_prob oldp) { |
| int delp = remap_prob(newp, oldp); |
| return update_bits[delp] << AV1_PROB_COST_SHIFT; |
| } |
| |
| static void encode_uniform(aom_writer *w, int v) { |
| const int l = 8; |
| const int m = (1 << l) - 190; |
| if (v < m) { |
| aom_write_literal(w, v, l - 1); |
| } else { |
| aom_write_literal(w, m + ((v - m) >> 1), l - 1); |
| aom_write_literal(w, (v - m) & 1, 1); |
| } |
| } |
| |
| static INLINE int write_bit_gte(aom_writer *w, int word, int test) { |
| aom_write_literal(w, word >= test, 1); |
| return word >= test; |
| } |
| |
| static void encode_term_subexp(aom_writer *w, int word) { |
| if (!write_bit_gte(w, word, 16)) { |
| aom_write_literal(w, word, 4); |
| } else if (!write_bit_gte(w, word, 32)) { |
| aom_write_literal(w, word - 16, 4); |
| } else if (!write_bit_gte(w, word, 64)) { |
| aom_write_literal(w, word - 32, 5); |
| } else { |
| encode_uniform(w, word - 64); |
| } |
| } |
| |
| void av1_write_prob_diff_update(aom_writer *w, aom_prob newp, aom_prob oldp) { |
| const int delp = remap_prob(newp, oldp); |
| encode_term_subexp(w, delp); |
| } |
| |
| int av1_prob_diff_update_savings_search(const unsigned int *ct, aom_prob oldp, |
| aom_prob *bestp, aom_prob upd, |
| int probwt) { |
| const uint32_t old_b = cost_branch256(ct, oldp); |
| int bestsavings = 0; |
| aom_prob newp, bestnewp = oldp; |
| const int step = *bestp > oldp ? -1 : 1; |
| const int upd_cost = av1_cost_one(upd) - av1_cost_zero(upd); |
| |
| if (old_b > (uint32_t)upd_cost + (MIN_DELP_BITS << AV1_PROB_COST_SHIFT)) { |
| for (newp = *bestp; newp != oldp; newp += step) { |
| const int new_b = cost_branch256(ct, newp); |
| const int update_b = prob_diff_update_cost(newp, oldp) + upd_cost; |
| const int savings = (int)((int64_t)old_b - new_b - update_b * probwt); |
| if (savings > bestsavings) { |
| bestsavings = savings; |
| bestnewp = newp; |
| } |
| } |
| } |
| *bestp = bestnewp; |
| return bestsavings; |
| } |
| |
| int av1_prob_diff_update_savings_search_model(const unsigned int *ct, |
| const aom_prob oldp, |
| aom_prob *bestp, aom_prob upd, |
| int stepsize, int probwt) { |
| int i, old_b, new_b, update_b, savings, bestsavings; |
| int newp; |
| const int step_sign = *bestp > oldp ? -1 : 1; |
| const int step = stepsize * step_sign; |
| const int upd_cost = av1_cost_one(upd) - av1_cost_zero(upd); |
| const aom_prob *newplist, *oldplist; |
| aom_prob bestnewp; |
| oldplist = av1_pareto8_full[oldp - 1]; |
| old_b = cost_branch256(ct + 2 * PIVOT_NODE, oldp); |
| for (i = UNCONSTRAINED_NODES; i < ENTROPY_NODES; ++i) |
| old_b += cost_branch256(ct + 2 * i, oldplist[i - UNCONSTRAINED_NODES]); |
| |
| bestsavings = 0; |
| bestnewp = oldp; |
| |
| assert(stepsize > 0); |
| |
| if (old_b > upd_cost + (MIN_DELP_BITS << AV1_PROB_COST_SHIFT)) { |
| for (newp = *bestp; (newp - oldp) * step_sign < 0; newp += step) { |
| if (newp < 1 || newp > 255) continue; |
| newplist = av1_pareto8_full[newp - 1]; |
| new_b = cost_branch256(ct + 2 * PIVOT_NODE, newp); |
| for (i = UNCONSTRAINED_NODES; i < ENTROPY_NODES; ++i) |
| new_b += cost_branch256(ct + 2 * i, newplist[i - UNCONSTRAINED_NODES]); |
| update_b = prob_diff_update_cost(newp, oldp) + upd_cost; |
| savings = old_b - new_b - update_b * probwt; |
| if (savings > bestsavings) { |
| bestsavings = savings; |
| bestnewp = newp; |
| } |
| } |
| } |
| |
| *bestp = bestnewp; |
| return bestsavings; |
| } |
| |
| void av1_cond_prob_diff_update(aom_writer *w, aom_prob *oldp, |
| const unsigned int ct[2], int probwt) { |
| const aom_prob upd = DIFF_UPDATE_PROB; |
| aom_prob newp = get_binary_prob(ct[0], ct[1]); |
| const int savings = |
| av1_prob_diff_update_savings_search(ct, *oldp, &newp, upd, probwt); |
| assert(newp >= 1); |
| if (savings > 0) { |
| aom_write(w, 1, upd); |
| av1_write_prob_diff_update(w, newp, *oldp); |
| *oldp = newp; |
| } else { |
| aom_write(w, 0, upd); |
| } |
| } |
| |
| int av1_cond_prob_diff_update_savings(aom_prob *oldp, const unsigned int ct[2], |
| int probwt) { |
| const aom_prob upd = DIFF_UPDATE_PROB; |
| aom_prob newp = get_binary_prob(ct[0], ct[1]); |
| const int savings = |
| av1_prob_diff_update_savings_search(ct, *oldp, &newp, upd, probwt); |
| return savings; |
| } |
