vp9_encodemv.c revision 9b35249446b07f40ac5fcc3205f2c048616efacc 
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 <math.h>
12
13#include "vp9/common/vp9_common.h"
14#include "vp9/common/vp9_entropymode.h"
15#include "vp9/common/vp9_systemdependent.h"
16#include "vp9/encoder/vp9_encodemv.h"
17
18
19#ifdef ENTROPY_STATS
20extern unsigned int active_section;
21#endif
22
23static void encode_mv_component(vp9_writer* w, int comp,
24                                const nmv_component* mvcomp, int usehp) {
25  int offset;
26  const int sign = comp < 0;
27  const int mag = sign ? -comp : comp;
28  const int mv_class = vp9_get_mv_class(mag - 1, &offset);
29  const int d = offset >> 3;                // int mv data
30  const int fr = (offset >> 1) & 3;         // fractional mv data
31  const int hp = offset & 1;                // high precision mv data
32
33  assert(comp != 0);
34
35  // Sign
36  vp9_write(w, sign, mvcomp->sign);
37
38  // Class
39  write_token(w, vp9_mv_class_tree, mvcomp->classes,
40              &vp9_mv_class_encodings[mv_class]);
41
42  // Integer bits
43  if (mv_class == MV_CLASS_0) {
44    write_token(w, vp9_mv_class0_tree, mvcomp->class0,
45                &vp9_mv_class0_encodings[d]);
46  } else {
47    int i;
48    const int n = mv_class + CLASS0_BITS - 1;  // number of bits
49    for (i = 0; i < n; ++i)
50      vp9_write(w, (d >> i) & 1, mvcomp->bits[i]);
51  }
52
53  // Fractional bits
54  write_token(w, vp9_mv_fp_tree,
55              mv_class == MV_CLASS_0 ?  mvcomp->class0_fp[d] : mvcomp->fp,
56              &vp9_mv_fp_encodings[fr]);
57
58  // High precision bit
59  if (usehp)
60    vp9_write(w, hp,
61              mv_class == MV_CLASS_0 ? mvcomp->class0_hp : mvcomp->hp);
62}
63
64
65static void build_nmv_component_cost_table(int *mvcost,
66                                           const nmv_component* const mvcomp,
67                                           int usehp) {
68  int i, v;
69  int sign_cost[2], class_cost[MV_CLASSES], class0_cost[CLASS0_SIZE];
70  int bits_cost[MV_OFFSET_BITS][2];
71  int class0_fp_cost[CLASS0_SIZE][4], fp_cost[4];
72  int class0_hp_cost[2], hp_cost[2];
73
74  sign_cost[0] = vp9_cost_zero(mvcomp->sign);
75  sign_cost[1] = vp9_cost_one(mvcomp->sign);
76  vp9_cost_tokens(class_cost, mvcomp->classes, vp9_mv_class_tree);
77  vp9_cost_tokens(class0_cost, mvcomp->class0, vp9_mv_class0_tree);
78  for (i = 0; i < MV_OFFSET_BITS; ++i) {
79    bits_cost[i][0] = vp9_cost_zero(mvcomp->bits[i]);
80    bits_cost[i][1] = vp9_cost_one(mvcomp->bits[i]);
81  }
82
83  for (i = 0; i < CLASS0_SIZE; ++i)
84    vp9_cost_tokens(class0_fp_cost[i], mvcomp->class0_fp[i], vp9_mv_fp_tree);
85  vp9_cost_tokens(fp_cost, mvcomp->fp, vp9_mv_fp_tree);
86
87  if (usehp) {
88    class0_hp_cost[0] = vp9_cost_zero(mvcomp->class0_hp);
89    class0_hp_cost[1] = vp9_cost_one(mvcomp->class0_hp);
90    hp_cost[0] = vp9_cost_zero(mvcomp->hp);
91    hp_cost[1] = vp9_cost_one(mvcomp->hp);
92  }
93  mvcost[0] = 0;
94  for (v = 1; v <= MV_MAX; ++v) {
95    int z, c, o, d, e, f, cost = 0;
96    z = v - 1;
97    c = vp9_get_mv_class(z, &o);
98    cost += class_cost[c];
99    d = (o >> 3);               /* int mv data */
100    f = (o >> 1) & 3;           /* fractional pel mv data */
101    e = (o & 1);                /* high precision mv data */
102    if (c == MV_CLASS_0) {
103      cost += class0_cost[d];
104    } else {
105      int i, b;
106      b = c + CLASS0_BITS - 1;  /* number of bits */
107      for (i = 0; i < b; ++i)
108        cost += bits_cost[i][((d >> i) & 1)];
109    }
110    if (c == MV_CLASS_0) {
111      cost += class0_fp_cost[d][f];
112    } else {
113      cost += fp_cost[f];
114    }
115    if (usehp) {
116      if (c == MV_CLASS_0) {
117        cost += class0_hp_cost[e];
118      } else {
119        cost += hp_cost[e];
120      }
121    }
122    mvcost[v] = cost + sign_cost[0];
123    mvcost[-v] = cost + sign_cost[1];
124  }
125}
126
127static int update_mv(vp9_writer *w, const unsigned int ct[2], vp9_prob *cur_p,
128                     vp9_prob upd_p) {
129  const vp9_prob new_p = get_binary_prob(ct[0], ct[1]);
130  vp9_prob mod_p = new_p | 1;
131  const int cur_b = cost_branch256(ct, *cur_p);
132  const int mod_b = cost_branch256(ct, mod_p);
133  const int cost = 7 * 256 + (vp9_cost_one(upd_p) - vp9_cost_zero(upd_p));
134  if (cur_b - mod_b > cost) {
135    *cur_p = mod_p;
136    vp9_write(w, 1, upd_p);
137    vp9_write_literal(w, mod_p >> 1, 7);
138    return 1;
139  } else {
140    vp9_write(w, 0, upd_p);
141    return 0;
142  }
143}
144
145static void counts_to_nmv_context(
146    nmv_context_counts *nmv_count,
147    int usehp,
148    unsigned int (*branch_ct_joint)[2],
149    unsigned int (*branch_ct_sign)[2],
150    unsigned int (*branch_ct_classes)[MV_CLASSES - 1][2],
151    unsigned int (*branch_ct_class0)[CLASS0_SIZE - 1][2],
152    unsigned int (*branch_ct_bits)[MV_OFFSET_BITS][2],
153    unsigned int (*branch_ct_class0_fp)[CLASS0_SIZE][4 - 1][2],
154    unsigned int (*branch_ct_fp)[4 - 1][2],
155    unsigned int (*branch_ct_class0_hp)[2],
156    unsigned int (*branch_ct_hp)[2]) {
157  int i, j, k;
158  vp9_tree_probs_from_distribution(vp9_mv_joint_tree, branch_ct_joint,
159                                   nmv_count->joints);
160  for (i = 0; i < 2; ++i) {
161    const uint32_t s0 = nmv_count->comps[i].sign[0];
162    const uint32_t s1 = nmv_count->comps[i].sign[1];
163
164    branch_ct_sign[i][0] = s0;
165    branch_ct_sign[i][1] = s1;
166    vp9_tree_probs_from_distribution(vp9_mv_class_tree,
167                                    branch_ct_classes[i],
168                                    nmv_count->comps[i].classes);
169    vp9_tree_probs_from_distribution(vp9_mv_class0_tree,
170                                     branch_ct_class0[i],
171                                     nmv_count->comps[i].class0);
172    for (j = 0; j < MV_OFFSET_BITS; ++j) {
173      const uint32_t b0 = nmv_count->comps[i].bits[j][0];
174      const uint32_t b1 = nmv_count->comps[i].bits[j][1];
175
176      branch_ct_bits[i][j][0] = b0;
177      branch_ct_bits[i][j][1] = b1;
178    }
179  }
180  for (i = 0; i < 2; ++i) {
181    for (k = 0; k < CLASS0_SIZE; ++k) {
182      vp9_tree_probs_from_distribution(vp9_mv_fp_tree,
183                                       branch_ct_class0_fp[i][k],
184                                       nmv_count->comps[i].class0_fp[k]);
185    }
186    vp9_tree_probs_from_distribution(vp9_mv_fp_tree,
187                                     branch_ct_fp[i],
188                                     nmv_count->comps[i].fp);
189  }
190  if (usehp) {
191    for (i = 0; i < 2; ++i) {
192      const uint32_t c0_hp0 = nmv_count->comps[i].class0_hp[0];
193      const uint32_t c0_hp1 = nmv_count->comps[i].class0_hp[1];
194      const uint32_t hp0 = nmv_count->comps[i].hp[0];
195      const uint32_t hp1 = nmv_count->comps[i].hp[1];
196
197      branch_ct_class0_hp[i][0] = c0_hp0;
198      branch_ct_class0_hp[i][1] = c0_hp1;
199
200      branch_ct_hp[i][0] = hp0;
201      branch_ct_hp[i][1] = hp1;
202    }
203  }
204}
205
206void vp9_write_nmv_probs(VP9_COMP* const cpi, int usehp, vp9_writer* const bc) {
207  int i, j;
208  unsigned int branch_ct_joint[MV_JOINTS - 1][2];
209  unsigned int branch_ct_sign[2][2];
210  unsigned int branch_ct_classes[2][MV_CLASSES - 1][2];
211  unsigned int branch_ct_class0[2][CLASS0_SIZE - 1][2];
212  unsigned int branch_ct_bits[2][MV_OFFSET_BITS][2];
213  unsigned int branch_ct_class0_fp[2][CLASS0_SIZE][4 - 1][2];
214  unsigned int branch_ct_fp[2][4 - 1][2];
215  unsigned int branch_ct_class0_hp[2][2];
216  unsigned int branch_ct_hp[2][2];
217  nmv_context *mvc = &cpi->common.fc.nmvc;
218
219  counts_to_nmv_context(&cpi->NMVcount, usehp,
220                        branch_ct_joint, branch_ct_sign, branch_ct_classes,
221                        branch_ct_class0, branch_ct_bits,
222                        branch_ct_class0_fp, branch_ct_fp,
223                        branch_ct_class0_hp, branch_ct_hp);
224
225  for (j = 0; j < MV_JOINTS - 1; ++j)
226    update_mv(bc, branch_ct_joint[j], &mvc->joints[j], NMV_UPDATE_PROB);
227
228  for (i = 0; i < 2; ++i) {
229    update_mv(bc, branch_ct_sign[i], &mvc->comps[i].sign, NMV_UPDATE_PROB);
230    for (j = 0; j < MV_CLASSES - 1; ++j)
231      update_mv(bc, branch_ct_classes[i][j], &mvc->comps[i].classes[j],
232                NMV_UPDATE_PROB);
233
234    for (j = 0; j < CLASS0_SIZE - 1; ++j)
235      update_mv(bc, branch_ct_class0[i][j], &mvc->comps[i].class0[j],
236                NMV_UPDATE_PROB);
237
238    for (j = 0; j < MV_OFFSET_BITS; ++j)
239      update_mv(bc, branch_ct_bits[i][j], &mvc->comps[i].bits[j],
240                NMV_UPDATE_PROB);
241  }
242
243  for (i = 0; i < 2; ++i) {
244    for (j = 0; j < CLASS0_SIZE; ++j) {
245      int k;
246      for (k = 0; k < 3; ++k)
247        update_mv(bc, branch_ct_class0_fp[i][j][k],
248                  &mvc->comps[i].class0_fp[j][k], NMV_UPDATE_PROB);
249    }
250
251    for (j = 0; j < 3; ++j)
252      update_mv(bc, branch_ct_fp[i][j], &mvc->comps[i].fp[j], NMV_UPDATE_PROB);
253  }
254
255  if (usehp) {
256    for (i = 0; i < 2; ++i) {
257      update_mv(bc, branch_ct_class0_hp[i], &mvc->comps[i].class0_hp,
258                NMV_UPDATE_PROB);
259      update_mv(bc, branch_ct_hp[i], &mvc->comps[i].hp,
260                NMV_UPDATE_PROB);
261    }
262  }
263}
264
265void vp9_encode_mv(VP9_COMP* cpi, vp9_writer* w,
266                   const MV* mv, const MV* ref,
267                   const nmv_context* mvctx, int usehp) {
268  const MV diff = {mv->row - ref->row,
269                   mv->col - ref->col};
270  const MV_JOINT_TYPE j = vp9_get_mv_joint(&diff);
271  usehp = usehp && vp9_use_mv_hp(ref);
272
273  write_token(w, vp9_mv_joint_tree, mvctx->joints, &vp9_mv_joint_encodings[j]);
274  if (mv_joint_vertical(j))
275    encode_mv_component(w, diff.row, &mvctx->comps[0], usehp);
276
277  if (mv_joint_horizontal(j))
278    encode_mv_component(w, diff.col, &mvctx->comps[1], usehp);
279
280  // If auto_mv_step_size is enabled then keep track of the largest
281  // motion vector component used.
282  if (!cpi->dummy_packing && cpi->sf.auto_mv_step_size) {
283    unsigned int maxv = MAX(abs(mv->row), abs(mv->col)) >> 3;
284    cpi->max_mv_magnitude = MAX(maxv, cpi->max_mv_magnitude);
285  }
286}
287
288void vp9_build_nmv_cost_table(int *mvjoint,
289                              int *mvcost[2],
290                              const nmv_context* const mvctx,
291                              int usehp,
292                              int mvc_flag_v,
293                              int mvc_flag_h) {
294  vp9_clear_system_state();
295  vp9_cost_tokens(mvjoint, mvctx->joints, vp9_mv_joint_tree);
296  if (mvc_flag_v)
297    build_nmv_component_cost_table(mvcost[0], &mvctx->comps[0], usehp);
298  if (mvc_flag_h)
299    build_nmv_component_cost_table(mvcost[1], &mvctx->comps[1], usehp);
300}
301
302static void inc_mvs(int_mv mv[2], int_mv ref[2], int is_compound,
303                    nmv_context_counts *counts) {
304  int i;
305  for (i = 0; i < 1 + is_compound; ++i) {
306    const MV diff = { mv[i].as_mv.row - ref[i].as_mv.row,
307                      mv[i].as_mv.col - ref[i].as_mv.col };
308    vp9_inc_mv(&diff, counts);
309  }
310}
311
312void vp9_update_mv_count(VP9_COMP *cpi, MACROBLOCK *x, int_mv best_ref_mv[2]) {
313  MODE_INFO *mi = x->e_mbd.mi_8x8[0];
314  MB_MODE_INFO *const mbmi = &mi->mbmi;
315  const int is_compound = has_second_ref(mbmi);
316
317  if (mbmi->sb_type < BLOCK_8X8) {
318    const int num_4x4_w = num_4x4_blocks_wide_lookup[mbmi->sb_type];
319    const int num_4x4_h = num_4x4_blocks_high_lookup[mbmi->sb_type];
320    int idx, idy;
321
322    for (idy = 0; idy < 2; idy += num_4x4_h) {
323      for (idx = 0; idx < 2; idx += num_4x4_w) {
324        const int i = idy * 2 + idx;
325        if (mi->bmi[i].as_mode == NEWMV)
326          inc_mvs(mi->bmi[i].as_mv, best_ref_mv, is_compound, &cpi->NMVcount);
327      }
328    }
329  } else if (mbmi->mode == NEWMV) {
330    inc_mvs(mbmi->mv, best_ref_mv, is_compound, &cpi->NMVcount);
331  }
332}
333