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
37 while (++i < 3);
38
39 i = mvlong_width - 1; /* Skip bit 3, which is sometimes implicit */
40
41 do
42 vp8_write(w, (x >> i) & 1, p[MVPbits + i]);
43
44 while (--i > 3);
45
46 if (x & 0xFFF0) vp8_write(w, (x >> 3) & 1, p[MVPbits + 3]);
47 }
48
49 vp8_write(w, v < 0, p[MVPsign]);
50 }
51 #if 0
52 static int max_mv_r = 0;
53 static int max_mv_c = 0;
54 #endif
vp8_encode_motion_vector(vp8_writer * w,const MV * mv,const MV_CONTEXT * mvc)55 void vp8_encode_motion_vector(vp8_writer *w, const MV *mv,
56 const MV_CONTEXT *mvc) {
57 #if 0
58 {
59 if (abs(mv->row >> 1) > max_mv_r)
60 {
61 FILE *f = fopen("maxmv.stt", "a");
62 max_mv_r = abs(mv->row >> 1);
63 fprintf(f, "New Mv Row Max %6d\n", (mv->row >> 1));
64
65 if ((abs(mv->row) / 2) != max_mv_r)
66 fprintf(f, "MV Row conversion error %6d\n", abs(mv->row) / 2);
67
68 fclose(f);
69 }
70
71 if (abs(mv->col >> 1) > max_mv_c)
72 {
73 FILE *f = fopen("maxmv.stt", "a");
74 fprintf(f, "New Mv Col Max %6d\n", (mv->col >> 1));
75 max_mv_c = abs(mv->col >> 1);
76 fclose(f);
77 }
78 }
79 #endif
80
81 encode_mvcomponent(w, mv->row >> 1, &mvc[0]);
82 encode_mvcomponent(w, mv->col >> 1, &mvc[1]);
83 }
84
cost_mvcomponent(const int v,const struct mv_context * mvc)85 static unsigned int cost_mvcomponent(const int v,
86 const struct mv_context *mvc) {
87 const vp8_prob *p = mvc->prob;
88 const int x = v;
89 unsigned int cost;
90
91 if (x < mvnum_short) {
92 cost = vp8_cost_zero(p[mvpis_short]) +
93 vp8_treed_cost(vp8_small_mvtree, p + MVPshort, x, 3);
94
95 if (!x) return cost;
96 } else {
97 int i = 0;
98 cost = vp8_cost_one(p[mvpis_short]);
99
100 do {
101 cost += vp8_cost_bit(p[MVPbits + i], (x >> i) & 1);
102
103 } while (++i < 3);
104
105 i = mvlong_width - 1; /* Skip bit 3, which is sometimes implicit */
106
107 do {
108 cost += vp8_cost_bit(p[MVPbits + i], (x >> i) & 1);
109
110 } while (--i > 3);
111
112 if (x & 0xFFF0) cost += vp8_cost_bit(p[MVPbits + 3], (x >> 3) & 1);
113 }
114
115 return cost; /* + vp8_cost_bit( p [MVPsign], v < 0); */
116 }
117
vp8_build_component_cost_table(int * mvcost[2],const MV_CONTEXT * mvc,int mvc_flag[2])118 void vp8_build_component_cost_table(int *mvcost[2], const MV_CONTEXT *mvc,
119 int mvc_flag[2]) {
120 int i = 1;
121 unsigned int cost0 = 0;
122 unsigned int cost1 = 0;
123
124 vpx_clear_system_state();
125
126 i = 1;
127
128 if (mvc_flag[0]) {
129 mvcost[0][0] = cost_mvcomponent(0, &mvc[0]);
130
131 do {
132 cost0 = cost_mvcomponent(i, &mvc[0]);
133
134 mvcost[0][i] = cost0 + vp8_cost_zero(mvc[0].prob[MVPsign]);
135 mvcost[0][-i] = cost0 + vp8_cost_one(mvc[0].prob[MVPsign]);
136 } while (++i <= mv_max);
137 }
138
139 i = 1;
140
141 if (mvc_flag[1]) {
142 mvcost[1][0] = cost_mvcomponent(0, &mvc[1]);
143
144 do {
145 cost1 = cost_mvcomponent(i, &mvc[1]);
146
147 mvcost[1][i] = cost1 + vp8_cost_zero(mvc[1].prob[MVPsign]);
148 mvcost[1][-i] = cost1 + vp8_cost_one(mvc[1].prob[MVPsign]);
149 } while (++i <= mv_max);
150 }
151 }
152
153 /* Motion vector probability table update depends on benefit.
154 * Small correction allows for the fact that an update to an MV probability
155 * may have benefit in subsequent frames as well as the current one.
156 */
157 #define MV_PROB_UPDATE_CORRECTION -1
158
calc_prob(vp8_prob * p,const unsigned int ct[2])159 static void calc_prob(vp8_prob *p, const unsigned int ct[2]) {
160 const unsigned int tot = ct[0] + ct[1];
161
162 if (tot) {
163 const vp8_prob x = ((ct[0] * 255) / tot) & -2;
164 *p = x ? x : 1;
165 }
166 }
167
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)168 static void update(vp8_writer *const w, const unsigned int ct[2],
169 vp8_prob *const cur_p, const vp8_prob new_p,
170 const vp8_prob update_p, int *updated) {
171 const int cur_b = vp8_cost_branch(ct, *cur_p);
172 const int new_b = vp8_cost_branch(ct, new_p);
173 const int cost =
174 7 + MV_PROB_UPDATE_CORRECTION +
175 ((vp8_cost_one(update_p) - vp8_cost_zero(update_p) + 128) >> 8);
176
177 if (cur_b - new_b > cost) {
178 *cur_p = new_p;
179 vp8_write(w, 1, update_p);
180 vp8_write_literal(w, new_p >> 1, 7);
181 *updated = 1;
182
183 } else
184 vp8_write(w, 0, update_p);
185 }
186
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)187 static void write_component_probs(vp8_writer *const w,
188 struct mv_context *cur_mvc,
189 const struct mv_context *default_mvc_,
190 const struct mv_context *update_mvc,
191 const unsigned int events[MVvals],
192 unsigned int rc, int *updated) {
193 vp8_prob *Pcur = cur_mvc->prob;
194 const vp8_prob *default_mvc = default_mvc_->prob;
195 const vp8_prob *Pupdate = update_mvc->prob;
196 unsigned int is_short_ct[2], sign_ct[2];
197
198 unsigned int bit_ct[mvlong_width][2];
199
200 unsigned int short_ct[mvnum_short];
201 unsigned int short_bct[mvnum_short - 1][2];
202
203 vp8_prob Pnew[MVPcount];
204
205 (void)rc;
206 vp8_copy_array(Pnew, default_mvc, MVPcount);
207
208 vp8_zero(is_short_ct) vp8_zero(sign_ct) vp8_zero(bit_ct) vp8_zero(short_ct)
209 vp8_zero(short_bct)
210
211 /* j=0 */
212 {
213 const int c = events[mv_max];
214
215 is_short_ct[0] += c; /* Short vector */
216 short_ct[0] += c; /* Magnitude distribution */
217 }
218
219 /* j: 1 ~ mv_max (1023) */
220 {
221 int j = 1;
222
223 do {
224 const int c1 = events[mv_max + j]; /* positive */
225 const int c2 = events[mv_max - j]; /* negative */
226 const int c = c1 + c2;
227 int a = j;
228
229 sign_ct[0] += c1;
230 sign_ct[1] += c2;
231
232 if (a < mvnum_short) {
233 is_short_ct[0] += c; /* Short vector */
234 short_ct[a] += c; /* Magnitude distribution */
235 } else {
236 int k = mvlong_width - 1;
237 is_short_ct[1] += c; /* Long vector */
238
239 /* bit 3 not always encoded. */
240 do {
241 bit_ct[k][(a >> k) & 1] += c;
242
243 } while (--k >= 0);
244 }
245 } while (++j <= mv_max);
246 }
247
248 calc_prob(Pnew + mvpis_short, is_short_ct);
249
250 calc_prob(Pnew + MVPsign, sign_ct);
251
252 {
253 vp8_prob p[mvnum_short - 1]; /* actually only need branch ct */
254 int j = 0;
255
256 vp8_tree_probs_from_distribution(8, vp8_small_mvencodings, vp8_small_mvtree,
257 p, short_bct, short_ct, 256, 1);
258
259 do {
260 calc_prob(Pnew + MVPshort + j, short_bct[j]);
261
262 } while (++j < mvnum_short - 1);
263 }
264
265 {
266 int j = 0;
267
268 do {
269 calc_prob(Pnew + MVPbits + j, bit_ct[j]);
270
271 } while (++j < mvlong_width);
272 }
273
274 update(w, is_short_ct, Pcur + mvpis_short, Pnew[mvpis_short], *Pupdate++,
275 updated);
276
277 update(w, sign_ct, Pcur + MVPsign, Pnew[MVPsign], *Pupdate++, updated);
278
279 {
280 const vp8_prob *const new_p = Pnew + MVPshort;
281 vp8_prob *const cur_p = Pcur + MVPshort;
282
283 int j = 0;
284
285 do {
286 update(w, short_bct[j], cur_p + j, new_p[j], *Pupdate++, updated);
287
288 } while (++j < mvnum_short - 1);
289 }
290
291 {
292 const vp8_prob *const new_p = Pnew + MVPbits;
293 vp8_prob *const cur_p = Pcur + MVPbits;
294
295 int j = 0;
296
297 do {
298 update(w, bit_ct[j], cur_p + j, new_p[j], *Pupdate++, updated);
299
300 } while (++j < mvlong_width);
301 }
302 }
303
vp8_write_mvprobs(VP8_COMP * cpi)304 void vp8_write_mvprobs(VP8_COMP *cpi) {
305 vp8_writer *const w = cpi->bc;
306 MV_CONTEXT *mvc = cpi->common.fc.mvc;
307 int flags[2] = { 0, 0 };
308 write_component_probs(w, &mvc[0], &vp8_default_mv_context[0],
309 &vp8_mv_update_probs[0], cpi->mb.MVcount[0], 0,
310 &flags[0]);
311 write_component_probs(w, &mvc[1], &vp8_default_mv_context[1],
312 &vp8_mv_update_probs[1], cpi->mb.MVcount[1], 1,
313 &flags[1]);
314
315 if (flags[0] || flags[1]) {
316 vp8_build_component_cost_table(
317 cpi->mb.mvcost, (const MV_CONTEXT *)cpi->common.fc.mvc, flags);
318 }
319 }
320