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 
16 #include "vp9/encoder/vp9_cost.h"
17 #include "vp9/encoder/vp9_encodemv.h"
18 
19 #include "vpx_dsp/vpx_dsp_common.h"
20 
21 static struct vp9_token mv_joint_encodings[MV_JOINTS];
22 static struct vp9_token mv_class_encodings[MV_CLASSES];
23 static struct vp9_token mv_fp_encodings[MV_FP_SIZE];
24 
vp9_entropy_mv_init(void)25 void vp9_entropy_mv_init(void) {
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_fp_encodings, vp9_mv_fp_tree);
29 }
30 
encode_mv_component(vpx_writer * w,int comp,const nmv_component * mvcomp,int usehp)31 static void encode_mv_component(vpx_writer *w, int comp,
32                                 const nmv_component *mvcomp, int usehp) {
33   int offset;
34   const int sign = comp < 0;
35   const int mag = sign ? -comp : comp;
36   const int mv_class = vp9_get_mv_class(mag - 1, &offset);
37   const int d = offset >> 3;         // int mv data
38   const int fr = (offset >> 1) & 3;  // fractional mv data
39   const int hp = offset & 1;         // high precision mv data
40 
41   assert(comp != 0);
42 
43   // Sign
44   vpx_write(w, sign, mvcomp->sign);
45 
46   // Class
47   vp9_write_token(w, vp9_mv_class_tree, mvcomp->classes,
48                   &mv_class_encodings[mv_class]);
49 
50   // Integer bits
51   if (mv_class == MV_CLASS_0) {
52     vpx_write(w, d, mvcomp->class0[0]);
53   } else {
54     int i;
55     const int n = mv_class + CLASS0_BITS - 1;  // number of bits
56     for (i = 0; i < n; ++i) vpx_write(w, (d >> i) & 1, mvcomp->bits[i]);
57   }
58 
59   // Fractional bits
60   vp9_write_token(w, vp9_mv_fp_tree,
61                   mv_class == MV_CLASS_0 ? mvcomp->class0_fp[d] : mvcomp->fp,
62                   &mv_fp_encodings[fr]);
63 
64   // High precision bit
65   if (usehp)
66     vpx_write(w, hp, mv_class == MV_CLASS_0 ? mvcomp->class0_hp : mvcomp->hp);
67 }
68 
build_nmv_component_cost_table(int * mvcost,const nmv_component * const mvcomp,int usehp)69 static void build_nmv_component_cost_table(int *mvcost,
70                                            const nmv_component *const mvcomp,
71                                            int usehp) {
72   int sign_cost[2], class_cost[MV_CLASSES], class0_cost[CLASS0_SIZE];
73   int bits_cost[MV_OFFSET_BITS][2];
74   int class0_fp_cost[CLASS0_SIZE][MV_FP_SIZE], fp_cost[MV_FP_SIZE];
75   int class0_hp_cost[2], hp_cost[2];
76   int i;
77   int c, o;
78 
79   sign_cost[0] = vp9_cost_zero(mvcomp->sign);
80   sign_cost[1] = vp9_cost_one(mvcomp->sign);
81   vp9_cost_tokens(class_cost, mvcomp->classes, vp9_mv_class_tree);
82   vp9_cost_tokens(class0_cost, mvcomp->class0, vp9_mv_class0_tree);
83   for (i = 0; i < MV_OFFSET_BITS; ++i) {
84     bits_cost[i][0] = vp9_cost_zero(mvcomp->bits[i]);
85     bits_cost[i][1] = vp9_cost_one(mvcomp->bits[i]);
86   }
87 
88   for (i = 0; i < CLASS0_SIZE; ++i)
89     vp9_cost_tokens(class0_fp_cost[i], mvcomp->class0_fp[i], vp9_mv_fp_tree);
90   vp9_cost_tokens(fp_cost, mvcomp->fp, vp9_mv_fp_tree);
91 
92   // Always build the hp costs to avoid an uninitialized warning from gcc
93   class0_hp_cost[0] = vp9_cost_zero(mvcomp->class0_hp);
94   class0_hp_cost[1] = vp9_cost_one(mvcomp->class0_hp);
95   hp_cost[0] = vp9_cost_zero(mvcomp->hp);
96   hp_cost[1] = vp9_cost_one(mvcomp->hp);
97 
98   mvcost[0] = 0;
99   // MV_CLASS_0
100   for (o = 0; o < (CLASS0_SIZE << 3); ++o) {
101     int d, e, f;
102     int cost = class_cost[MV_CLASS_0];
103     int v = o + 1;
104     d = (o >> 3);     /* int mv data */
105     f = (o >> 1) & 3; /* fractional pel mv data */
106     cost += class0_cost[d];
107     cost += class0_fp_cost[d][f];
108     if (usehp) {
109       e = (o & 1); /* high precision mv data */
110       cost += class0_hp_cost[e];
111     }
112     mvcost[v] = cost + sign_cost[0];
113     mvcost[-v] = cost + sign_cost[1];
114   }
115   for (c = MV_CLASS_1; c < MV_CLASSES; ++c) {
116     int d;
117     for (d = 0; d < (1 << c); ++d) {
118       int f;
119       int whole_cost = class_cost[c];
120       int b = c + CLASS0_BITS - 1; /* number of bits */
121       for (i = 0; i < b; ++i) whole_cost += bits_cost[i][((d >> i) & 1)];
122       for (f = 0; f < 4; ++f) {
123         int cost = whole_cost + fp_cost[f];
124         int v = (CLASS0_SIZE << (c + 2)) + d * 8 + f * 2 /* + e */ + 1;
125         if (usehp) {
126           mvcost[v] = cost + hp_cost[0] + sign_cost[0];
127           mvcost[-v] = cost + hp_cost[0] + sign_cost[1];
128           if (v + 1 > MV_MAX) break;
129           mvcost[v + 1] = cost + hp_cost[1] + sign_cost[0];
130           mvcost[-v - 1] = cost + hp_cost[1] + sign_cost[1];
131         } else {
132           mvcost[v] = cost + sign_cost[0];
133           mvcost[-v] = cost + sign_cost[1];
134           if (v + 1 > MV_MAX) break;
135           mvcost[v + 1] = cost + sign_cost[0];
136           mvcost[-v - 1] = cost + sign_cost[1];
137         }
138       }
139     }
140   }
141 }
142 
update_mv(vpx_writer * w,const unsigned int ct[2],vpx_prob * cur_p,vpx_prob upd_p)143 static int update_mv(vpx_writer *w, const unsigned int ct[2], vpx_prob *cur_p,
144                      vpx_prob upd_p) {
145   const vpx_prob new_p = get_binary_prob(ct[0], ct[1]) | 1;
146   const int update = cost_branch256(ct, *cur_p) + vp9_cost_zero(upd_p) >
147                      cost_branch256(ct, new_p) + vp9_cost_one(upd_p) +
148                          (7 << VP9_PROB_COST_SHIFT);
149   vpx_write(w, update, upd_p);
150   if (update) {
151     *cur_p = new_p;
152     vpx_write_literal(w, new_p >> 1, 7);
153   }
154   return update;
155 }
156 
write_mv_update(const vpx_tree_index * tree,vpx_prob probs[],const unsigned int counts[],int n,vpx_writer * w)157 static void write_mv_update(const vpx_tree_index *tree,
158                             vpx_prob probs[/*n - 1*/],
159                             const unsigned int counts[/*n - 1*/], int n,
160                             vpx_writer *w) {
161   int i;
162   unsigned int branch_ct[32][2];
163 
164   // Assuming max number of probabilities <= 32
165   assert(n <= 32);
166 
167   vp9_tree_probs_from_distribution(tree, branch_ct, counts);
168   for (i = 0; i < n - 1; ++i)
169     update_mv(w, branch_ct[i], &probs[i], MV_UPDATE_PROB);
170 }
171 
vp9_write_nmv_probs(VP9_COMMON * cm,int usehp,vpx_writer * w,nmv_context_counts * const counts)172 void vp9_write_nmv_probs(VP9_COMMON *cm, int usehp, vpx_writer *w,
173                          nmv_context_counts *const counts) {
174   int i, j;
175   nmv_context *const mvc = &cm->fc->nmvc;
176 
177   write_mv_update(vp9_mv_joint_tree, mvc->joints, counts->joints, MV_JOINTS, w);
178 
179   for (i = 0; i < 2; ++i) {
180     nmv_component *comp = &mvc->comps[i];
181     nmv_component_counts *comp_counts = &counts->comps[i];
182 
183     update_mv(w, comp_counts->sign, &comp->sign, MV_UPDATE_PROB);
184     write_mv_update(vp9_mv_class_tree, comp->classes, comp_counts->classes,
185                     MV_CLASSES, w);
186     write_mv_update(vp9_mv_class0_tree, comp->class0, comp_counts->class0,
187                     CLASS0_SIZE, w);
188     for (j = 0; j < MV_OFFSET_BITS; ++j)
189       update_mv(w, comp_counts->bits[j], &comp->bits[j], MV_UPDATE_PROB);
190   }
191 
192   for (i = 0; i < 2; ++i) {
193     for (j = 0; j < CLASS0_SIZE; ++j)
194       write_mv_update(vp9_mv_fp_tree, mvc->comps[i].class0_fp[j],
195                       counts->comps[i].class0_fp[j], MV_FP_SIZE, w);
196 
197     write_mv_update(vp9_mv_fp_tree, mvc->comps[i].fp, counts->comps[i].fp,
198                     MV_FP_SIZE, w);
199   }
200 
201   if (usehp) {
202     for (i = 0; i < 2; ++i) {
203       update_mv(w, counts->comps[i].class0_hp, &mvc->comps[i].class0_hp,
204                 MV_UPDATE_PROB);
205       update_mv(w, counts->comps[i].hp, &mvc->comps[i].hp, MV_UPDATE_PROB);
206     }
207   }
208 }
209 
vp9_encode_mv(VP9_COMP * cpi,vpx_writer * w,const MV * mv,const MV * ref,const nmv_context * mvctx,int usehp,unsigned int * const max_mv_magnitude)210 void vp9_encode_mv(VP9_COMP *cpi, vpx_writer *w, const MV *mv, const MV *ref,
211                    const nmv_context *mvctx, int usehp,
212                    unsigned int *const max_mv_magnitude) {
213   const MV diff = { mv->row - ref->row, mv->col - ref->col };
214   const MV_JOINT_TYPE j = vp9_get_mv_joint(&diff);
215   usehp = usehp && use_mv_hp(ref);
216 
217   vp9_write_token(w, vp9_mv_joint_tree, mvctx->joints, &mv_joint_encodings[j]);
218   if (mv_joint_vertical(j))
219     encode_mv_component(w, diff.row, &mvctx->comps[0], usehp);
220 
221   if (mv_joint_horizontal(j))
222     encode_mv_component(w, diff.col, &mvctx->comps[1], usehp);
223 
224   // If auto_mv_step_size is enabled then keep track of the largest
225   // motion vector component used.
226   if (cpi->sf.mv.auto_mv_step_size) {
227     const unsigned int maxv = VPXMAX(abs(mv->row), abs(mv->col)) >> 3;
228     *max_mv_magnitude = VPXMAX(maxv, *max_mv_magnitude);
229   }
230 }
231 
vp9_build_nmv_cost_table(int * mvjoint,int * mvcost[2],const nmv_context * ctx,int usehp)232 void vp9_build_nmv_cost_table(int *mvjoint, int *mvcost[2],
233                               const nmv_context *ctx, int usehp) {
234   vp9_cost_tokens(mvjoint, ctx->joints, vp9_mv_joint_tree);
235   build_nmv_component_cost_table(mvcost[0], &ctx->comps[0], usehp);
236   build_nmv_component_cost_table(mvcost[1], &ctx->comps[1], usehp);
237 }
238 
inc_mvs(const MODE_INFO * mi,const MB_MODE_INFO_EXT * mbmi_ext,const int_mv mvs[2],nmv_context_counts * counts)239 static void inc_mvs(const MODE_INFO *mi, const MB_MODE_INFO_EXT *mbmi_ext,
240                     const int_mv mvs[2], nmv_context_counts *counts) {
241   int i;
242 
243   for (i = 0; i < 1 + has_second_ref(mi); ++i) {
244     const MV *ref = &mbmi_ext->ref_mvs[mi->ref_frame[i]][0].as_mv;
245     const MV diff = { mvs[i].as_mv.row - ref->row,
246                       mvs[i].as_mv.col - ref->col };
247     vp9_inc_mv(&diff, counts);
248   }
249 }
250 
vp9_update_mv_count(ThreadData * td)251 void vp9_update_mv_count(ThreadData *td) {
252   const MACROBLOCKD *xd = &td->mb.e_mbd;
253   const MODE_INFO *mi = xd->mi[0];
254   const MB_MODE_INFO_EXT *mbmi_ext = td->mb.mbmi_ext;
255 
256   if (mi->sb_type < BLOCK_8X8) {
257     const int num_4x4_w = num_4x4_blocks_wide_lookup[mi->sb_type];
258     const int num_4x4_h = num_4x4_blocks_high_lookup[mi->sb_type];
259     int idx, idy;
260 
261     for (idy = 0; idy < 2; idy += num_4x4_h) {
262       for (idx = 0; idx < 2; idx += num_4x4_w) {
263         const int i = idy * 2 + idx;
264         if (mi->bmi[i].as_mode == NEWMV)
265           inc_mvs(mi, mbmi_ext, mi->bmi[i].as_mv, &td->counts->mv);
266       }
267     }
268   } else {
269     if (mi->mode == NEWMV) inc_mvs(mi, mbmi_ext, mi->mv, &td->counts->mv);
270   }
271 }
272