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