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 
17 #include "vp9/encoder/vp9_cost.h"
18 #include "vp9/encoder/vp9_encodemv.h"
19 
20 static struct vp9_token mv_joint_encodings[MV_JOINTS];
21 static struct vp9_token mv_class_encodings[MV_CLASSES];
22 static struct vp9_token mv_fp_encodings[MV_FP_SIZE];
23 static struct vp9_token mv_class0_encodings[CLASS0_SIZE];
24 
vp9_entropy_mv_init()25 void vp9_entropy_mv_init() {
26   vp9_tokens_from_tree(mv_joint_encodings, vp9_mv_joint_tree);
27   vp9_tokens_from_tree(mv_class_encodings, vp9_mv_class_tree);
28   vp9_tokens_from_tree(mv_class0_encodings, vp9_mv_class0_tree);
29   vp9_tokens_from_tree(mv_fp_encodings, vp9_mv_fp_tree);
30 }
31 
encode_mv_component(vp9_writer * w,int comp,const nmv_component * mvcomp,int usehp)32 static void encode_mv_component(vp9_writer* w, int comp,
33                                 const nmv_component* mvcomp, int usehp) {
34   int offset;
35   const int sign = comp < 0;
36   const int mag = sign ? -comp : comp;
37   const int mv_class = vp9_get_mv_class(mag - 1, &offset);
38   const int d = offset >> 3;                // int mv data
39   const int fr = (offset >> 1) & 3;         // fractional mv data
40   const int hp = offset & 1;                // high precision mv data
41 
42   assert(comp != 0);
43 
44   // Sign
45   vp9_write(w, sign, mvcomp->sign);
46 
47   // Class
48   vp9_write_token(w, vp9_mv_class_tree, mvcomp->classes,
49                   &mv_class_encodings[mv_class]);
50 
51   // Integer bits
52   if (mv_class == MV_CLASS_0) {
53     vp9_write_token(w, vp9_mv_class0_tree, mvcomp->class0,
54                     &mv_class0_encodings[d]);
55   } else {
56     int i;
57     const int n = mv_class + CLASS0_BITS - 1;  // number of bits
58     for (i = 0; i < n; ++i)
59       vp9_write(w, (d >> i) & 1, mvcomp->bits[i]);
60   }
61 
62   // Fractional bits
63   vp9_write_token(w, vp9_mv_fp_tree,
64                   mv_class == MV_CLASS_0 ?  mvcomp->class0_fp[d] : mvcomp->fp,
65                   &mv_fp_encodings[fr]);
66 
67   // High precision bit
68   if (usehp)
69     vp9_write(w, hp,
70               mv_class == MV_CLASS_0 ? mvcomp->class0_hp : mvcomp->hp);
71 }
72 
73 
build_nmv_component_cost_table(int * mvcost,const nmv_component * const mvcomp,int usehp)74 static void build_nmv_component_cost_table(int *mvcost,
75                                            const nmv_component* const mvcomp,
76                                            int usehp) {
77   int i, v;
78   int sign_cost[2], class_cost[MV_CLASSES], class0_cost[CLASS0_SIZE];
79   int bits_cost[MV_OFFSET_BITS][2];
80   int class0_fp_cost[CLASS0_SIZE][MV_FP_SIZE], fp_cost[MV_FP_SIZE];
81   int class0_hp_cost[2], hp_cost[2];
82 
83   sign_cost[0] = vp9_cost_zero(mvcomp->sign);
84   sign_cost[1] = vp9_cost_one(mvcomp->sign);
85   vp9_cost_tokens(class_cost, mvcomp->classes, vp9_mv_class_tree);
86   vp9_cost_tokens(class0_cost, mvcomp->class0, vp9_mv_class0_tree);
87   for (i = 0; i < MV_OFFSET_BITS; ++i) {
88     bits_cost[i][0] = vp9_cost_zero(mvcomp->bits[i]);
89     bits_cost[i][1] = vp9_cost_one(mvcomp->bits[i]);
90   }
91 
92   for (i = 0; i < CLASS0_SIZE; ++i)
93     vp9_cost_tokens(class0_fp_cost[i], mvcomp->class0_fp[i], vp9_mv_fp_tree);
94   vp9_cost_tokens(fp_cost, mvcomp->fp, vp9_mv_fp_tree);
95 
96   if (usehp) {
97     class0_hp_cost[0] = vp9_cost_zero(mvcomp->class0_hp);
98     class0_hp_cost[1] = vp9_cost_one(mvcomp->class0_hp);
99     hp_cost[0] = vp9_cost_zero(mvcomp->hp);
100     hp_cost[1] = vp9_cost_one(mvcomp->hp);
101   }
102   mvcost[0] = 0;
103   for (v = 1; v <= MV_MAX; ++v) {
104     int z, c, o, d, e, f, cost = 0;
105     z = v - 1;
106     c = vp9_get_mv_class(z, &o);
107     cost += class_cost[c];
108     d = (o >> 3);               /* int mv data */
109     f = (o >> 1) & 3;           /* fractional pel mv data */
110     e = (o & 1);                /* high precision mv data */
111     if (c == MV_CLASS_0) {
112       cost += class0_cost[d];
113     } else {
114       int i, b;
115       b = c + CLASS0_BITS - 1;  /* number of bits */
116       for (i = 0; i < b; ++i)
117         cost += bits_cost[i][((d >> i) & 1)];
118     }
119     if (c == MV_CLASS_0) {
120       cost += class0_fp_cost[d][f];
121     } else {
122       cost += fp_cost[f];
123     }
124     if (usehp) {
125       if (c == MV_CLASS_0) {
126         cost += class0_hp_cost[e];
127       } else {
128         cost += hp_cost[e];
129       }
130     }
131     mvcost[v] = cost + sign_cost[0];
132     mvcost[-v] = cost + sign_cost[1];
133   }
134 }
135 
update_mv(vp9_writer * w,const unsigned int ct[2],vp9_prob * cur_p,vp9_prob upd_p)136 static int update_mv(vp9_writer *w, const unsigned int ct[2], vp9_prob *cur_p,
137                      vp9_prob upd_p) {
138   const vp9_prob new_p = get_binary_prob(ct[0], ct[1]) | 1;
139   const int update = cost_branch256(ct, *cur_p) + vp9_cost_zero(upd_p) >
140                      cost_branch256(ct, new_p) + vp9_cost_one(upd_p) + 7 * 256;
141   vp9_write(w, update, upd_p);
142   if (update) {
143     *cur_p = new_p;
144     vp9_write_literal(w, new_p >> 1, 7);
145   }
146   return update;
147 }
148 
write_mv_update(const vp9_tree_index * tree,vp9_prob probs[],const unsigned int counts[],int n,vp9_writer * w)149 static void write_mv_update(const vp9_tree_index *tree,
150                             vp9_prob probs[/*n - 1*/],
151                             const unsigned int counts[/*n - 1*/],
152                             int n, vp9_writer *w) {
153   int i;
154   unsigned int branch_ct[32][2];
155 
156   // Assuming max number of probabilities <= 32
157   assert(n <= 32);
158 
159   vp9_tree_probs_from_distribution(tree, branch_ct, counts);
160   for (i = 0; i < n - 1; ++i)
161     update_mv(w, branch_ct[i], &probs[i], MV_UPDATE_PROB);
162 }
163 
vp9_write_nmv_probs(VP9_COMMON * cm,int usehp,vp9_writer * w)164 void vp9_write_nmv_probs(VP9_COMMON *cm, int usehp, vp9_writer *w) {
165   int i, j;
166   nmv_context *const mvc = &cm->fc.nmvc;
167   nmv_context_counts *const counts = &cm->counts.mv;
168 
169   write_mv_update(vp9_mv_joint_tree, mvc->joints, counts->joints, MV_JOINTS, w);
170 
171   for (i = 0; i < 2; ++i) {
172     nmv_component *comp = &mvc->comps[i];
173     nmv_component_counts *comp_counts = &counts->comps[i];
174 
175     update_mv(w, comp_counts->sign, &comp->sign, MV_UPDATE_PROB);
176     write_mv_update(vp9_mv_class_tree, comp->classes, comp_counts->classes,
177                     MV_CLASSES, w);
178     write_mv_update(vp9_mv_class0_tree, comp->class0, comp_counts->class0,
179                     CLASS0_SIZE, w);
180     for (j = 0; j < MV_OFFSET_BITS; ++j)
181       update_mv(w, comp_counts->bits[j], &comp->bits[j], MV_UPDATE_PROB);
182   }
183 
184   for (i = 0; i < 2; ++i) {
185     for (j = 0; j < CLASS0_SIZE; ++j)
186       write_mv_update(vp9_mv_fp_tree, mvc->comps[i].class0_fp[j],
187                       counts->comps[i].class0_fp[j], MV_FP_SIZE, w);
188 
189     write_mv_update(vp9_mv_fp_tree, mvc->comps[i].fp, counts->comps[i].fp,
190                     MV_FP_SIZE, w);
191   }
192 
193   if (usehp) {
194     for (i = 0; i < 2; ++i) {
195       update_mv(w, counts->comps[i].class0_hp, &mvc->comps[i].class0_hp,
196                 MV_UPDATE_PROB);
197       update_mv(w, counts->comps[i].hp, &mvc->comps[i].hp, MV_UPDATE_PROB);
198     }
199   }
200 }
201 
vp9_encode_mv(VP9_COMP * cpi,vp9_writer * w,const MV * mv,const MV * ref,const nmv_context * mvctx,int usehp)202 void vp9_encode_mv(VP9_COMP* cpi, vp9_writer* w,
203                    const MV* mv, const MV* ref,
204                    const nmv_context* mvctx, int usehp) {
205   const MV diff = {mv->row - ref->row,
206                    mv->col - ref->col};
207   const MV_JOINT_TYPE j = vp9_get_mv_joint(&diff);
208   usehp = usehp && vp9_use_mv_hp(ref);
209 
210   vp9_write_token(w, vp9_mv_joint_tree, mvctx->joints, &mv_joint_encodings[j]);
211   if (mv_joint_vertical(j))
212     encode_mv_component(w, diff.row, &mvctx->comps[0], usehp);
213 
214   if (mv_joint_horizontal(j))
215     encode_mv_component(w, diff.col, &mvctx->comps[1], usehp);
216 
217   // If auto_mv_step_size is enabled then keep track of the largest
218   // motion vector component used.
219   if (!cpi->dummy_packing && cpi->sf.mv.auto_mv_step_size) {
220     unsigned int maxv = MAX(abs(mv->row), abs(mv->col)) >> 3;
221     cpi->max_mv_magnitude = MAX(maxv, cpi->max_mv_magnitude);
222   }
223 }
224 
vp9_build_nmv_cost_table(int * mvjoint,int * mvcost[2],const nmv_context * ctx,int usehp)225 void vp9_build_nmv_cost_table(int *mvjoint, int *mvcost[2],
226                               const nmv_context* ctx, int usehp) {
227   vp9_cost_tokens(mvjoint, ctx->joints, vp9_mv_joint_tree);
228   build_nmv_component_cost_table(mvcost[0], &ctx->comps[0], usehp);
229   build_nmv_component_cost_table(mvcost[1], &ctx->comps[1], usehp);
230 }
231 
inc_mvs(const MB_MODE_INFO * mbmi,const int_mv mvs[2],nmv_context_counts * counts)232 static void inc_mvs(const MB_MODE_INFO *mbmi, const int_mv mvs[2],
233                     nmv_context_counts *counts) {
234   int i;
235 
236   for (i = 0; i < 1 + has_second_ref(mbmi); ++i) {
237     const MV *ref = &mbmi->ref_mvs[mbmi->ref_frame[i]][0].as_mv;
238     const MV diff = {mvs[i].as_mv.row - ref->row,
239                      mvs[i].as_mv.col - ref->col};
240     vp9_inc_mv(&diff, counts);
241   }
242 }
243 
vp9_update_mv_count(VP9_COMMON * cm,const MACROBLOCKD * xd)244 void vp9_update_mv_count(VP9_COMMON *cm, const MACROBLOCKD *xd) {
245   const MODE_INFO *mi = xd->mi[0];
246   const MB_MODE_INFO *const mbmi = &mi->mbmi;
247 
248   if (mbmi->sb_type < BLOCK_8X8) {
249     const int num_4x4_w = num_4x4_blocks_wide_lookup[mbmi->sb_type];
250     const int num_4x4_h = num_4x4_blocks_high_lookup[mbmi->sb_type];
251     int idx, idy;
252 
253     for (idy = 0; idy < 2; idy += num_4x4_h) {
254       for (idx = 0; idx < 2; idx += num_4x4_w) {
255         const int i = idy * 2 + idx;
256         if (mi->bmi[i].as_mode == NEWMV)
257           inc_mvs(mbmi, mi->bmi[i].as_mv, &cm->counts.mv);
258       }
259     }
260   } else {
261     if (mbmi->mode == NEWMV)
262       inc_mvs(mbmi, mbmi->mv, &cm->counts.mv);
263   }
264 }
265 
266