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 { 30 vp8_write(w, 0, p[mvpis_short]); 31 vp8_treed_write(w, vp8_small_mvtree, p + MVPshort, x, 3); 32 33 if (!x) return; /* no sign bit */ 34 } else /* Large */ 35 { 36 int i = 0; 37 38 vp8_write(w, 1, p[mvpis_short]); 39 40 do 41 vp8_write(w, (x >> i) & 1, p[MVPbits + i]); 42 43 while (++i < 3); 44 45 i = mvlong_width - 1; /* Skip bit 3, which is sometimes implicit */ 46 47 do 48 vp8_write(w, (x >> i) & 1, p[MVPbits + i]); 49 50 while (--i > 3); 51 52 if (x & 0xFFF0) vp8_write(w, (x >> 3) & 1, p[MVPbits + 3]); 53 } 54 55 vp8_write(w, v < 0, p[MVPsign]); 56 } 57 #if 0 58 static int max_mv_r = 0; 59 static int max_mv_c = 0; 60 #endif 61 void vp8_encode_motion_vector(vp8_writer *w, const MV *mv, 62 const MV_CONTEXT *mvc) { 63 #if 0 64 { 65 if (abs(mv->row >> 1) > max_mv_r) 66 { 67 FILE *f = fopen("maxmv.stt", "a"); 68 max_mv_r = abs(mv->row >> 1); 69 fprintf(f, "New Mv Row Max %6d\n", (mv->row >> 1)); 70 71 if ((abs(mv->row) / 2) != max_mv_r) 72 fprintf(f, "MV Row conversion error %6d\n", abs(mv->row) / 2); 73 74 fclose(f); 75 } 76 77 if (abs(mv->col >> 1) > max_mv_c) 78 { 79 FILE *f = fopen("maxmv.stt", "a"); 80 fprintf(f, "New Mv Col Max %6d\n", (mv->col >> 1)); 81 max_mv_c = abs(mv->col >> 1); 82 fclose(f); 83 } 84 } 85 #endif 86 87 encode_mvcomponent(w, mv->row >> 1, &mvc[0]); 88 encode_mvcomponent(w, mv->col >> 1, &mvc[1]); 89 } 90 91 static unsigned int cost_mvcomponent(const int v, 92 const struct mv_context *mvc) { 93 const vp8_prob *p = mvc->prob; 94 const int x = v; 95 unsigned int cost; 96 97 if (x < mvnum_short) { 98 cost = vp8_cost_zero(p[mvpis_short]) + 99 vp8_treed_cost(vp8_small_mvtree, p + MVPshort, x, 3); 100 101 if (!x) return cost; 102 } else { 103 int i = 0; 104 cost = vp8_cost_one(p[mvpis_short]); 105 106 do { 107 cost += vp8_cost_bit(p[MVPbits + i], (x >> i) & 1); 108 109 } while (++i < 3); 110 111 i = mvlong_width - 1; /* Skip bit 3, which is sometimes implicit */ 112 113 do { 114 cost += vp8_cost_bit(p[MVPbits + i], (x >> i) & 1); 115 116 } while (--i > 3); 117 118 if (x & 0xFFF0) cost += vp8_cost_bit(p[MVPbits + 3], (x >> 3) & 1); 119 } 120 121 return cost; /* + vp8_cost_bit( p [MVPsign], v < 0); */ 122 } 123 124 void vp8_build_component_cost_table(int *mvcost[2], const MV_CONTEXT *mvc, 125 int mvc_flag[2]) { 126 int i = 1; 127 unsigned int cost0 = 0; 128 unsigned int cost1 = 0; 129 130 vpx_clear_system_state(); 131 132 i = 1; 133 134 if (mvc_flag[0]) { 135 mvcost[0][0] = cost_mvcomponent(0, &mvc[0]); 136 137 do { 138 cost0 = cost_mvcomponent(i, &mvc[0]); 139 140 mvcost[0][i] = cost0 + vp8_cost_zero(mvc[0].prob[MVPsign]); 141 mvcost[0][-i] = cost0 + vp8_cost_one(mvc[0].prob[MVPsign]); 142 } while (++i <= mv_max); 143 } 144 145 i = 1; 146 147 if (mvc_flag[1]) { 148 mvcost[1][0] = cost_mvcomponent(0, &mvc[1]); 149 150 do { 151 cost1 = cost_mvcomponent(i, &mvc[1]); 152 153 mvcost[1][i] = cost1 + vp8_cost_zero(mvc[1].prob[MVPsign]); 154 mvcost[1][-i] = cost1 + vp8_cost_one(mvc[1].prob[MVPsign]); 155 } while (++i <= mv_max); 156 } 157 } 158 159 /* Motion vector probability table update depends on benefit. 160 * Small correction allows for the fact that an update to an MV probability 161 * may have benefit in subsequent frames as well as the current one. 162 */ 163 #define MV_PROB_UPDATE_CORRECTION -1 164 165 static void calc_prob(vp8_prob *p, const unsigned int ct[2]) { 166 const unsigned int tot = ct[0] + ct[1]; 167 168 if (tot) { 169 const vp8_prob x = ((ct[0] * 255) / tot) & -2; 170 *p = x ? x : 1; 171 } 172 } 173 174 static void update(vp8_writer *const w, const unsigned int ct[2], 175 vp8_prob *const cur_p, const vp8_prob new_p, 176 const vp8_prob update_p, int *updated) { 177 const int cur_b = vp8_cost_branch(ct, *cur_p); 178 const int new_b = vp8_cost_branch(ct, new_p); 179 const int cost = 180 7 + MV_PROB_UPDATE_CORRECTION + 181 ((vp8_cost_one(update_p) - vp8_cost_zero(update_p) + 128) >> 8); 182 183 if (cur_b - new_b > cost) { 184 *cur_p = new_p; 185 vp8_write(w, 1, update_p); 186 vp8_write_literal(w, new_p >> 1, 7); 187 *updated = 1; 188 189 } else 190 vp8_write(w, 0, update_p); 191 } 192 193 static void write_component_probs(vp8_writer *const w, 194 struct mv_context *cur_mvc, 195 const struct mv_context *default_mvc_, 196 const struct mv_context *update_mvc, 197 const unsigned int events[MVvals], 198 unsigned int rc, int *updated) { 199 vp8_prob *Pcur = cur_mvc->prob; 200 const vp8_prob *default_mvc = default_mvc_->prob; 201 const vp8_prob *Pupdate = update_mvc->prob; 202 unsigned int is_short_ct[2], sign_ct[2]; 203 204 unsigned int bit_ct[mvlong_width][2]; 205 206 unsigned int short_ct[mvnum_short]; 207 unsigned int short_bct[mvnum_short - 1][2]; 208 209 vp8_prob Pnew[MVPcount]; 210 211 (void)rc; 212 vp8_copy_array(Pnew, default_mvc, MVPcount); 213 214 vp8_zero(is_short_ct) vp8_zero(sign_ct) vp8_zero(bit_ct) vp8_zero(short_ct) 215 vp8_zero(short_bct) 216 217 /* j=0 */ 218 { 219 const int c = events[mv_max]; 220 221 is_short_ct[0] += c; /* Short vector */ 222 short_ct[0] += c; /* Magnitude distribution */ 223 } 224 225 /* j: 1 ~ mv_max (1023) */ 226 { 227 int j = 1; 228 229 do { 230 const int c1 = events[mv_max + j]; /* positive */ 231 const int c2 = events[mv_max - j]; /* negative */ 232 const int c = c1 + c2; 233 int a = j; 234 235 sign_ct[0] += c1; 236 sign_ct[1] += c2; 237 238 if (a < mvnum_short) { 239 is_short_ct[0] += c; /* Short vector */ 240 short_ct[a] += c; /* Magnitude distribution */ 241 } else { 242 int k = mvlong_width - 1; 243 is_short_ct[1] += c; /* Long vector */ 244 245 /* bit 3 not always encoded. */ 246 do { 247 bit_ct[k][(a >> k) & 1] += c; 248 249 } while (--k >= 0); 250 } 251 } while (++j <= mv_max); 252 } 253 254 calc_prob(Pnew + mvpis_short, is_short_ct); 255 256 calc_prob(Pnew + MVPsign, sign_ct); 257 258 { 259 vp8_prob p[mvnum_short - 1]; /* actually only need branch ct */ 260 int j = 0; 261 262 vp8_tree_probs_from_distribution(8, vp8_small_mvencodings, vp8_small_mvtree, 263 p, short_bct, short_ct, 256, 1); 264 265 do { 266 calc_prob(Pnew + MVPshort + j, short_bct[j]); 267 268 } while (++j < mvnum_short - 1); 269 } 270 271 { 272 int j = 0; 273 274 do { 275 calc_prob(Pnew + MVPbits + j, bit_ct[j]); 276 277 } while (++j < mvlong_width); 278 } 279 280 update(w, is_short_ct, Pcur + mvpis_short, Pnew[mvpis_short], *Pupdate++, 281 updated); 282 283 update(w, sign_ct, Pcur + MVPsign, Pnew[MVPsign], *Pupdate++, updated); 284 285 { 286 const vp8_prob *const new_p = Pnew + MVPshort; 287 vp8_prob *const cur_p = Pcur + MVPshort; 288 289 int j = 0; 290 291 do { 292 update(w, short_bct[j], cur_p + j, new_p[j], *Pupdate++, updated); 293 294 } while (++j < mvnum_short - 1); 295 } 296 297 { 298 const vp8_prob *const new_p = Pnew + MVPbits; 299 vp8_prob *const cur_p = Pcur + MVPbits; 300 301 int j = 0; 302 303 do { 304 update(w, bit_ct[j], cur_p + j, new_p[j], *Pupdate++, updated); 305 306 } while (++j < mvlong_width); 307 } 308 } 309 310 void vp8_write_mvprobs(VP8_COMP *cpi) { 311 vp8_writer *const w = cpi->bc; 312 MV_CONTEXT *mvc = cpi->common.fc.mvc; 313 int flags[2] = { 0, 0 }; 314 #ifdef VP8_ENTROPY_STATS 315 active_section = 4; 316 #endif 317 write_component_probs(w, &mvc[0], &vp8_default_mv_context[0], 318 &vp8_mv_update_probs[0], cpi->mb.MVcount[0], 0, 319 &flags[0]); 320 write_component_probs(w, &mvc[1], &vp8_default_mv_context[1], 321 &vp8_mv_update_probs[1], cpi->mb.MVcount[1], 1, 322 &flags[1]); 323 324 if (flags[0] || flags[1]) { 325 vp8_build_component_cost_table( 326 cpi->mb.mvcost, (const MV_CONTEXT *)cpi->common.fc.mvc, flags); 327 } 328 329 #ifdef VP8_ENTROPY_STATS 330 active_section = 5; 331 #endif 332 } 333
