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
12 #include "common.h"
13 #include "encodemv.h"
14 #include "entropymode.h"
15 #include "systemdependent.h"
16
17 #include <math.h>
18
19 #ifdef ENTROPY_STATS
20 extern unsigned int active_section;
21 #endif
22
encode_mvcomponent(vp8_writer * const w,const int v,const struct mv_context * mvc)23 static void encode_mvcomponent(
24 vp8_writer *const w,
25 const int v,
26 const struct mv_context *mvc
27 )
28 {
29 const vp8_prob *p = mvc->prob;
30 const int x = v < 0 ? -v : v;
31
32 if (x < mvnum_short) // Small
33 {
34 vp8_write(w, 0, p [mvpis_short]);
35 vp8_treed_write(w, vp8_small_mvtree, p + MVPshort, x, 3);
36
37 if (!x)
38 return; // no sign bit
39 }
40 else // Large
41 {
42 int i = 0;
43
44 vp8_write(w, 1, p [mvpis_short]);
45
46 do
47 vp8_write(w, (x >> i) & 1, p [MVPbits + i]);
48
49 while (++i < 3);
50
51 i = mvlong_width - 1; /* Skip bit 3, which is sometimes implicit */
52
53 do
54 vp8_write(w, (x >> i) & 1, p [MVPbits + i]);
55
56 while (--i > 3);
57
58 if (x & 0xFFF0)
59 vp8_write(w, (x >> 3) & 1, p [MVPbits + 3]);
60 }
61
62 vp8_write(w, v < 0, p [MVPsign]);
63 }
64 #if 0
65 static int max_mv_r = 0;
66 static int max_mv_c = 0;
67 #endif
vp8_encode_motion_vector(vp8_writer * w,const MV * mv,const MV_CONTEXT * mvc)68 void vp8_encode_motion_vector(vp8_writer *w, const MV *mv, const MV_CONTEXT *mvc)
69 {
70
71 #if 0
72 {
73 if (abs(mv->row >> 1) > max_mv_r)
74 {
75 FILE *f = fopen("maxmv.stt", "a");
76 max_mv_r = abs(mv->row >> 1);
77 fprintf(f, "New Mv Row Max %6d\n", (mv->row >> 1));
78
79 if ((abs(mv->row) / 2) != max_mv_r)
80 fprintf(f, "MV Row conversion error %6d\n", abs(mv->row) / 2);
81
82 fclose(f);
83 }
84
85 if (abs(mv->col >> 1) > max_mv_c)
86 {
87 FILE *f = fopen("maxmv.stt", "a");
88 fprintf(f, "New Mv Col Max %6d\n", (mv->col >> 1));
89 max_mv_c = abs(mv->col >> 1);
90 fclose(f);
91 }
92 }
93 #endif
94
95 encode_mvcomponent(w, mv->row >> 1, &mvc[0]);
96 encode_mvcomponent(w, mv->col >> 1, &mvc[1]);
97 }
98
99
cost_mvcomponent(const int v,const struct mv_context * mvc)100 static unsigned int cost_mvcomponent(const int v, const struct mv_context *mvc)
101 {
102 const vp8_prob *p = mvc->prob;
103 const int x = v; //v<0? -v:v;
104 unsigned int cost;
105
106 if (x < mvnum_short)
107 {
108 cost = vp8_cost_zero(p [mvpis_short])
109 + vp8_treed_cost(vp8_small_mvtree, p + MVPshort, x, 3);
110
111 if (!x)
112 return cost;
113 }
114 else
115 {
116 int i = 0;
117 cost = vp8_cost_one(p [mvpis_short]);
118
119 do
120 cost += vp8_cost_bit(p [MVPbits + i], (x >> i) & 1);
121
122 while (++i < 3);
123
124 i = mvlong_width - 1; /* Skip bit 3, which is sometimes implicit */
125
126 do
127 cost += vp8_cost_bit(p [MVPbits + i], (x >> i) & 1);
128
129 while (--i > 3);
130
131 if (x & 240)
132 cost += vp8_cost_bit(p [MVPbits + 3], (x >> 3) & 1);
133 }
134
135 return cost; // + vp8_cost_bit( p [MVPsign], v < 0);
136 }
137 //#define M_LOG2_E 0.693147180559945309417
138 //#define log2f(x) (log (x) / (float) M_LOG2_E)
139
vp8_build_component_cost_table(int * mvcost[2],int * mvsadcost[2],const MV_CONTEXT * mvc,int mvc_flag[2])140 void vp8_build_component_cost_table(int *mvcost[2], int *mvsadcost[2], const MV_CONTEXT *mvc, int mvc_flag[2])
141 {
142 int i = 1; //-mv_max;
143 unsigned int cost0 = 0;
144 unsigned int cost1 = 0;
145
146 vp8_clear_system_state();
147 #if 0
148 mvsadcost [0] [0] = 300;
149 mvsadcost [1] [0] = 300;
150
151 do
152 {
153 double z = 256 * (2 * (log2f(2 * i) + .6));
154 mvsadcost [0][i] = (int) z;
155 mvsadcost [1][i] = (int) z;
156 mvsadcost [0][-i] = (int) z;
157 mvsadcost [1][-i] = (int) z;
158 }
159 while (++i <= mv_max);
160
161 #endif
162
163 i = 1;
164
165 if (mvc_flag[0])
166 {
167 mvcost [0] [0] = cost_mvcomponent(0, &mvc[0]);
168
169 do
170 {
171 //mvcost [0] [i] = cost_mvcomponent( i, &mvc[0]);
172 cost0 = cost_mvcomponent(i, &mvc[0]);
173
174 mvcost [0] [i] = cost0 + vp8_cost_zero(mvc[0].prob[MVPsign]);
175 mvcost [0] [-i] = cost0 + vp8_cost_one(mvc[0].prob[MVPsign]);
176 }
177 while (++i <= mv_max);
178 }
179
180 i = 1;
181
182 if (mvc_flag[1])
183 {
184 mvcost [1] [0] = cost_mvcomponent(0, &mvc[1]);
185
186 do
187 {
188 //mvcost [1] [i] = cost_mvcomponent( i, mvc[1]);
189 cost1 = cost_mvcomponent(i, &mvc[1]);
190
191 mvcost [1] [i] = cost1 + vp8_cost_zero(mvc[1].prob[MVPsign]);
192 mvcost [1] [-i] = cost1 + vp8_cost_one(mvc[1].prob[MVPsign]);
193 }
194 while (++i <= mv_max);
195 }
196
197 /*
198 i=-mv_max;
199 do
200 {
201 mvcost [0] [i] = cost_mvcomponent( i, mvc[0]);
202 mvcost [1] [i] = cost_mvcomponent( i, mvc[1]);
203 }
204 while( ++i <= mv_max);
205 */
206 }
207
208
209 // Motion vector probability table update depends on benefit.
210 // Small correction allows for the fact that an update to an MV probability
211 // may have benefit in subsequent frames as well as the current one.
212
213 #define MV_PROB_UPDATE_CORRECTION -1
214
215
calc_prob(vp8_prob * p,const unsigned int ct[2])216 __inline static void calc_prob(vp8_prob *p, const unsigned int ct[2])
217 {
218 const unsigned int tot = ct[0] + ct[1];
219
220 if (tot)
221 {
222 const vp8_prob x = ((ct[0] * 255) / tot) & -2;
223 *p = x ? x : 1;
224 }
225 }
226
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)227 static void update(
228 vp8_writer *const w,
229 const unsigned int ct[2],
230 vp8_prob *const cur_p,
231 const vp8_prob new_p,
232 const vp8_prob update_p,
233 int *updated
234 )
235 {
236 const int cur_b = vp8_cost_branch(ct, *cur_p);
237 const int new_b = vp8_cost_branch(ct, new_p);
238 const int cost = 7 + MV_PROB_UPDATE_CORRECTION + ((vp8_cost_one(update_p) - vp8_cost_zero(update_p) + 128) >> 8);
239
240 if (cur_b - new_b > cost)
241 {
242 *cur_p = new_p;
243 vp8_write(w, 1, update_p);
244 vp8_write_literal(w, new_p >> 1, 7);
245 *updated = 1;
246
247 }
248 else
249 vp8_write(w, 0, update_p);
250 }
251
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)252 static void write_component_probs(
253 vp8_writer *const w,
254 struct mv_context *cur_mvc,
255 const struct mv_context *default_mvc_,
256 const struct mv_context *update_mvc,
257 const unsigned int events [MVvals],
258 unsigned int rc,
259 int *updated
260 )
261 {
262 vp8_prob *Pcur = cur_mvc->prob;
263 const vp8_prob *default_mvc = default_mvc_->prob;
264 const vp8_prob *Pupdate = update_mvc->prob;
265 unsigned int is_short_ct[2], sign_ct[2];
266
267 unsigned int bit_ct [mvlong_width] [2];
268
269 unsigned int short_ct [mvnum_short];
270 unsigned int short_bct [mvnum_short-1] [2];
271
272 vp8_prob Pnew [MVPcount];
273
274 (void) rc;
275 vp8_copy_array(Pnew, default_mvc, MVPcount);
276
277 vp8_zero(is_short_ct)
278 vp8_zero(sign_ct)
279 vp8_zero(bit_ct)
280 vp8_zero(short_ct)
281 vp8_zero(short_bct)
282
283
284 //j=0
285 {
286 const int c = events [mv_max];
287
288 is_short_ct [0] += c; // Short vector
289 short_ct [0] += c; // Magnitude distribution
290 }
291
292 //j: 1 ~ mv_max (1023)
293 {
294 int j = 1;
295
296 do
297 {
298 const int c1 = events [mv_max + j]; //positive
299 const int c2 = events [mv_max - j]; //negative
300 const int c = c1 + c2;
301 int a = j;
302
303 sign_ct [0] += c1;
304 sign_ct [1] += c2;
305
306 if (a < mvnum_short)
307 {
308 is_short_ct [0] += c; // Short vector
309 short_ct [a] += c; // Magnitude distribution
310 }
311 else
312 {
313 int k = mvlong_width - 1;
314 is_short_ct [1] += c; // Long vector
315
316 /* bit 3 not always encoded. */
317 do
318 bit_ct [k] [(a >> k) & 1] += c;
319
320 while (--k >= 0);
321 }
322 }
323 while (++j <= mv_max);
324 }
325
326 /*
327 {
328 int j = -mv_max;
329 do
330 {
331
332 const int c = events [mv_max + j];
333 int a = j;
334
335 if( j < 0)
336 {
337 sign_ct [1] += c;
338 a = -j;
339 }
340 else if( j)
341 sign_ct [0] += c;
342
343 if( a < mvnum_short)
344 {
345 is_short_ct [0] += c; // Short vector
346 short_ct [a] += c; // Magnitude distribution
347 }
348 else
349 {
350 int k = mvlong_width - 1;
351 is_short_ct [1] += c; // Long vector
352
353 // bit 3 not always encoded.
354
355 do
356 bit_ct [k] [(a >> k) & 1] += c;
357 while( --k >= 0);
358 }
359 } while( ++j <= mv_max);
360 }
361 */
362
363 calc_prob(Pnew + mvpis_short, is_short_ct);
364
365 calc_prob(Pnew + MVPsign, sign_ct);
366
367 {
368 vp8_prob p [mvnum_short - 1]; /* actually only need branch ct */
369 int j = 0;
370
371 vp8_tree_probs_from_distribution(
372 8, vp8_small_mvencodings, vp8_small_mvtree,
373 p, short_bct, short_ct,
374 256, 1
375 );
376
377 do
378 calc_prob(Pnew + MVPshort + j, short_bct[j]);
379
380 while (++j < mvnum_short - 1);
381 }
382
383 {
384 int j = 0;
385
386 do
387 calc_prob(Pnew + MVPbits + j, bit_ct[j]);
388
389 while (++j < mvlong_width);
390 }
391
392 update(w, is_short_ct, Pcur + mvpis_short, Pnew[mvpis_short], *Pupdate++, updated);
393
394 update(w, sign_ct, Pcur + MVPsign, Pnew[MVPsign], *Pupdate++, updated);
395
396 {
397 const vp8_prob *const new_p = Pnew + MVPshort;
398 vp8_prob *const cur_p = Pcur + MVPshort;
399
400 int j = 0;
401
402 do
403
404 update(w, short_bct[j], cur_p + j, new_p[j], *Pupdate++, updated);
405
406 while (++j < mvnum_short - 1);
407 }
408
409 {
410 const vp8_prob *const new_p = Pnew + MVPbits;
411 vp8_prob *const cur_p = Pcur + MVPbits;
412
413 int j = 0;
414
415 do
416
417 update(w, bit_ct[j], cur_p + j, new_p[j], *Pupdate++, updated);
418
419 while (++j < mvlong_width);
420 }
421 }
422
vp8_write_mvprobs(VP8_COMP * cpi)423 void vp8_write_mvprobs(VP8_COMP *cpi)
424 {
425 vp8_writer *const w = & cpi->bc;
426 MV_CONTEXT *mvc = cpi->common.fc.mvc;
427 int flags[2] = {0, 0};
428 #ifdef ENTROPY_STATS
429 active_section = 4;
430 #endif
431 write_component_probs(
432 w, &mvc[0], &vp8_default_mv_context[0], &vp8_mv_update_probs[0], cpi->MVcount[0], 0, &flags[0]
433 );
434 write_component_probs(
435 w, &mvc[1], &vp8_default_mv_context[1], &vp8_mv_update_probs[1], cpi->MVcount[1], 1, &flags[1]
436 );
437
438 if (flags[0] || flags[1])
439 vp8_build_component_cost_table(cpi->mb.mvcost, cpi->mb.mvsadcost, (const MV_CONTEXT *) cpi->common.fc.mvc, flags);
440
441 #ifdef ENTROPY_STATS
442 active_section = 5;
443 #endif
444 }
445