1 /* 2 * Copyright (c) 2010 The WebM project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #include "vp8/common/common.h" 12 #include "encodemv.h" 13 #include "vp8/common/entropymode.h" 14 #include "vp8/common/systemdependent.h" 15 #include "vpx_ports/system_state.h" 16 17 #include <math.h> 18 19 #ifdef VP8_ENTROPY_STATS 20 extern unsigned int active_section; 21 #endif 22 23 static void encode_mvcomponent(vp8_writer *const w, const int v, 24 const struct mv_context *mvc) { 25 const vp8_prob *p = mvc->prob; 26 const int x = v < 0 ? -v : v; 27 28 if (x < mvnum_short) { /* Small */ 29 vp8_write(w, 0, p[mvpis_short]); 30 vp8_treed_write(w, vp8_small_mvtree, p + MVPshort, x, 3); 31 32 if (!x) return; /* no sign bit */ 33 } else { /* Large */ 34 int i = 0; 35 36 vp8_write(w, 1, p[mvpis_short]); 37 38 do 39 vp8_write(w, (x >> i) & 1, p[MVPbits + i]); 40 41 while (++i < 3); 42 43 i = mvlong_width - 1; /* Skip bit 3, which is sometimes implicit */ 44 45 do 46 vp8_write(w, (x >> i) & 1, p[MVPbits + i]); 47 48 while (--i > 3); 49 50 if (x & 0xFFF0) vp8_write(w, (x >> 3) & 1, p[MVPbits + 3]); 51 } 52 53 vp8_write(w, v < 0, p[MVPsign]); 54 } 55 #if 0 56 static int max_mv_r = 0; 57 static int max_mv_c = 0; 58 #endif 59 void vp8_encode_motion_vector(vp8_writer *w, const MV *mv, 60 const MV_CONTEXT *mvc) { 61 #if 0 62 { 63 if (abs(mv->row >> 1) > max_mv_r) 64 { 65 FILE *f = fopen("maxmv.stt", "a"); 66 max_mv_r = abs(mv->row >> 1); 67 fprintf(f, "New Mv Row Max %6d\n", (mv->row >> 1)); 68 69 if ((abs(mv->row) / 2) != max_mv_r) 70 fprintf(f, "MV Row conversion error %6d\n", abs(mv->row) / 2); 71 72 fclose(f); 73 } 74 75 if (abs(mv->col >> 1) > max_mv_c) 76 { 77 FILE *f = fopen("maxmv.stt", "a"); 78 fprintf(f, "New Mv Col Max %6d\n", (mv->col >> 1)); 79 max_mv_c = abs(mv->col >> 1); 80 fclose(f); 81 } 82 } 83 #endif 84 85 encode_mvcomponent(w, mv->row >> 1, &mvc[0]); 86 encode_mvcomponent(w, mv->col >> 1, &mvc[1]); 87 } 88 89 static unsigned int cost_mvcomponent(const int v, 90 const struct mv_context *mvc) { 91 const vp8_prob *p = mvc->prob; 92 const int x = v; 93 unsigned int cost; 94 95 if (x < mvnum_short) { 96 cost = vp8_cost_zero(p[mvpis_short]) + 97 vp8_treed_cost(vp8_small_mvtree, p + MVPshort, x, 3); 98 99 if (!x) return cost; 100 } else { 101 int i = 0; 102 cost = vp8_cost_one(p[mvpis_short]); 103 104 do { 105 cost += vp8_cost_bit(p[MVPbits + i], (x >> i) & 1); 106 107 } while (++i < 3); 108 109 i = mvlong_width - 1; /* Skip bit 3, which is sometimes implicit */ 110 111 do { 112 cost += vp8_cost_bit(p[MVPbits + i], (x >> i) & 1); 113 114 } while (--i > 3); 115 116 if (x & 0xFFF0) cost += vp8_cost_bit(p[MVPbits + 3], (x >> 3) & 1); 117 } 118 119 return cost; /* + vp8_cost_bit( p [MVPsign], v < 0); */ 120 } 121 122 void vp8_build_component_cost_table(int *mvcost[2], const MV_CONTEXT *mvc, 123 int mvc_flag[2]) { 124 int i = 1; 125 unsigned int cost0 = 0; 126 unsigned int cost1 = 0; 127 128 vpx_clear_system_state(); 129 130 i = 1; 131 132 if (mvc_flag[0]) { 133 mvcost[0][0] = cost_mvcomponent(0, &mvc[0]); 134 135 do { 136 cost0 = cost_mvcomponent(i, &mvc[0]); 137 138 mvcost[0][i] = cost0 + vp8_cost_zero(mvc[0].prob[MVPsign]); 139 mvcost[0][-i] = cost0 + vp8_cost_one(mvc[0].prob[MVPsign]); 140 } while (++i <= mv_max); 141 } 142 143 i = 1; 144 145 if (mvc_flag[1]) { 146 mvcost[1][0] = cost_mvcomponent(0, &mvc[1]); 147 148 do { 149 cost1 = cost_mvcomponent(i, &mvc[1]); 150 151 mvcost[1][i] = cost1 + vp8_cost_zero(mvc[1].prob[MVPsign]); 152 mvcost[1][-i] = cost1 + vp8_cost_one(mvc[1].prob[MVPsign]); 153 } while (++i <= mv_max); 154 } 155 } 156 157 /* Motion vector probability table update depends on benefit. 158 * Small correction allows for the fact that an update to an MV probability 159 * may have benefit in subsequent frames as well as the current one. 160 */ 161 #define MV_PROB_UPDATE_CORRECTION -1 162 163 static void calc_prob(vp8_prob *p, const unsigned int ct[2]) { 164 const unsigned int tot = ct[0] + ct[1]; 165 166 if (tot) { 167 const vp8_prob x = ((ct[0] * 255) / tot) & -2; 168 *p = x ? x : 1; 169 } 170 } 171 172 static void update(vp8_writer *const w, const unsigned int ct[2], 173 vp8_prob *const cur_p, const vp8_prob new_p, 174 const vp8_prob update_p, int *updated) { 175 const int cur_b = vp8_cost_branch(ct, *cur_p); 176 const int new_b = vp8_cost_branch(ct, new_p); 177 const int cost = 178 7 + MV_PROB_UPDATE_CORRECTION + 179 ((vp8_cost_one(update_p) - vp8_cost_zero(update_p) + 128) >> 8); 180 181 if (cur_b - new_b > cost) { 182 *cur_p = new_p; 183 vp8_write(w, 1, update_p); 184 vp8_write_literal(w, new_p >> 1, 7); 185 *updated = 1; 186 187 } else 188 vp8_write(w, 0, update_p); 189 } 190 191 static void write_component_probs(vp8_writer *const w, 192 struct mv_context *cur_mvc, 193 const struct mv_context *default_mvc_, 194 const struct mv_context *update_mvc, 195 const unsigned int events[MVvals], 196 unsigned int rc, int *updated) { 197 vp8_prob *Pcur = cur_mvc->prob; 198 const vp8_prob *default_mvc = default_mvc_->prob; 199 const vp8_prob *Pupdate = update_mvc->prob; 200 unsigned int is_short_ct[2], sign_ct[2]; 201 202 unsigned int bit_ct[mvlong_width][2]; 203 204 unsigned int short_ct[mvnum_short]; 205 unsigned int short_bct[mvnum_short - 1][2]; 206 207 vp8_prob Pnew[MVPcount]; 208 209 (void)rc; 210 vp8_copy_array(Pnew, default_mvc, MVPcount); 211 212 vp8_zero(is_short_ct) vp8_zero(sign_ct) vp8_zero(bit_ct) vp8_zero(short_ct) 213 vp8_zero(short_bct) 214 215 /* j=0 */ 216 { 217 const int c = events[mv_max]; 218 219 is_short_ct[0] += c; /* Short vector */ 220 short_ct[0] += c; /* Magnitude distribution */ 221 } 222 223 /* j: 1 ~ mv_max (1023) */ 224 { 225 int j = 1; 226 227 do { 228 const int c1 = events[mv_max + j]; /* positive */ 229 const int c2 = events[mv_max - j]; /* negative */ 230 const int c = c1 + c2; 231 int a = j; 232 233 sign_ct[0] += c1; 234 sign_ct[1] += c2; 235 236 if (a < mvnum_short) { 237 is_short_ct[0] += c; /* Short vector */ 238 short_ct[a] += c; /* Magnitude distribution */ 239 } else { 240 int k = mvlong_width - 1; 241 is_short_ct[1] += c; /* Long vector */ 242 243 /* bit 3 not always encoded. */ 244 do { 245 bit_ct[k][(a >> k) & 1] += c; 246 247 } while (--k >= 0); 248 } 249 } while (++j <= mv_max); 250 } 251 252 calc_prob(Pnew + mvpis_short, is_short_ct); 253 254 calc_prob(Pnew + MVPsign, sign_ct); 255 256 { 257 vp8_prob p[mvnum_short - 1]; /* actually only need branch ct */ 258 int j = 0; 259 260 vp8_tree_probs_from_distribution(8, vp8_small_mvencodings, vp8_small_mvtree, 261 p, short_bct, short_ct, 256, 1); 262 263 do { 264 calc_prob(Pnew + MVPshort + j, short_bct[j]); 265 266 } while (++j < mvnum_short - 1); 267 } 268 269 { 270 int j = 0; 271 272 do { 273 calc_prob(Pnew + MVPbits + j, bit_ct[j]); 274 275 } while (++j < mvlong_width); 276 } 277 278 update(w, is_short_ct, Pcur + mvpis_short, Pnew[mvpis_short], *Pupdate++, 279 updated); 280 281 update(w, sign_ct, Pcur + MVPsign, Pnew[MVPsign], *Pupdate++, updated); 282 283 { 284 const vp8_prob *const new_p = Pnew + MVPshort; 285 vp8_prob *const cur_p = Pcur + MVPshort; 286 287 int j = 0; 288 289 do { 290 update(w, short_bct[j], cur_p + j, new_p[j], *Pupdate++, updated); 291 292 } while (++j < mvnum_short - 1); 293 } 294 295 { 296 const vp8_prob *const new_p = Pnew + MVPbits; 297 vp8_prob *const cur_p = Pcur + MVPbits; 298 299 int j = 0; 300 301 do { 302 update(w, bit_ct[j], cur_p + j, new_p[j], *Pupdate++, updated); 303 304 } while (++j < mvlong_width); 305 } 306 } 307 308 void vp8_write_mvprobs(VP8_COMP *cpi) { 309 vp8_writer *const w = cpi->bc; 310 MV_CONTEXT *mvc = cpi->common.fc.mvc; 311 int flags[2] = { 0, 0 }; 312 #ifdef VP8_ENTROPY_STATS 313 active_section = 4; 314 #endif 315 write_component_probs(w, &mvc[0], &vp8_default_mv_context[0], 316 &vp8_mv_update_probs[0], cpi->mb.MVcount[0], 0, 317 &flags[0]); 318 write_component_probs(w, &mvc[1], &vp8_default_mv_context[1], 319 &vp8_mv_update_probs[1], cpi->mb.MVcount[1], 1, 320 &flags[1]); 321 322 if (flags[0] || flags[1]) { 323 vp8_build_component_cost_table( 324 cpi->mb.mvcost, (const MV_CONTEXT *)cpi->common.fc.mvc, flags); 325 } 326 327 #ifdef VP8_ENTROPY_STATS 328 active_section = 5; 329 #endif 330 } 331
