1// Copyright 2011 Google Inc. All Rights Reserved. 2// 3// Use of this source code is governed by a BSD-style license 4// that can be found in the COPYING file in the root of the source 5// tree. An additional intellectual property rights grant can be found 6// in the file PATENTS. All contributing project authors may 7// be found in the AUTHORS file in the root of the source tree. 8// ----------------------------------------------------------------------------- 9// 10// frame coding and analysis 11// 12// Author: Skal (pascal.massimino@gmail.com) 13 14#include <string.h> 15#include <math.h> 16 17#include "./cost.h" 18#include "./vp8enci.h" 19#include "../dsp/dsp.h" 20#include "../webp/format_constants.h" // RIFF constants 21 22#define SEGMENT_VISU 0 23#define DEBUG_SEARCH 0 // useful to track search convergence 24 25//------------------------------------------------------------------------------ 26// multi-pass convergence 27 28#define HEADER_SIZE_ESTIMATE (RIFF_HEADER_SIZE + CHUNK_HEADER_SIZE + \ 29 VP8_FRAME_HEADER_SIZE) 30#define DQ_LIMIT 0.4 // convergence is considered reached if dq < DQ_LIMIT 31// we allow 2k of extra head-room in PARTITION0 limit. 32#define PARTITION0_SIZE_LIMIT ((VP8_MAX_PARTITION0_SIZE - 2048ULL) << 11) 33 34typedef struct { // struct for organizing convergence in either size or PSNR 35 int is_first; 36 float dq; 37 float q, last_q; 38 double value, last_value; // PSNR or size 39 double target; 40 int do_size_search; 41} PassStats; 42 43static int InitPassStats(const VP8Encoder* const enc, PassStats* const s) { 44 const uint64_t target_size = (uint64_t)enc->config_->target_size; 45 const int do_size_search = (target_size != 0); 46 const float target_PSNR = enc->config_->target_PSNR; 47 48 s->is_first = 1; 49 s->dq = 10.f; 50 s->q = s->last_q = enc->config_->quality; 51 s->target = do_size_search ? (double)target_size 52 : (target_PSNR > 0.) ? target_PSNR 53 : 40.; // default, just in case 54 s->value = s->last_value = 0.; 55 s->do_size_search = do_size_search; 56 return do_size_search; 57} 58 59static float Clamp(float v, float min, float max) { 60 return (v < min) ? min : (v > max) ? max : v; 61} 62 63static float ComputeNextQ(PassStats* const s) { 64 float dq; 65 if (s->is_first) { 66 dq = (s->value > s->target) ? -s->dq : s->dq; 67 s->is_first = 0; 68 } else if (s->value != s->last_value) { 69 const double slope = (s->target - s->value) / (s->last_value - s->value); 70 dq = (float)(slope * (s->last_q - s->q)); 71 } else { 72 dq = 0.; // we're done?! 73 } 74 // Limit variable to avoid large swings. 75 s->dq = Clamp(dq, -30.f, 30.f); 76 s->last_q = s->q; 77 s->last_value = s->value; 78 s->q = Clamp(s->q + s->dq, 0.f, 100.f); 79 return s->q; 80} 81 82//------------------------------------------------------------------------------ 83// Tables for level coding 84 85const uint8_t VP8Cat3[] = { 173, 148, 140 }; 86const uint8_t VP8Cat4[] = { 176, 155, 140, 135 }; 87const uint8_t VP8Cat5[] = { 180, 157, 141, 134, 130 }; 88const uint8_t VP8Cat6[] = 89 { 254, 254, 243, 230, 196, 177, 153, 140, 133, 130, 129 }; 90 91//------------------------------------------------------------------------------ 92// Reset the statistics about: number of skips, token proba, level cost,... 93 94static void ResetStats(VP8Encoder* const enc) { 95 VP8EncProba* const proba = &enc->proba_; 96 VP8CalculateLevelCosts(proba); 97 proba->nb_skip_ = 0; 98} 99 100//------------------------------------------------------------------------------ 101// Skip decision probability 102 103#define SKIP_PROBA_THRESHOLD 250 // value below which using skip_proba is OK. 104 105static int CalcSkipProba(uint64_t nb, uint64_t total) { 106 return (int)(total ? (total - nb) * 255 / total : 255); 107} 108 109// Returns the bit-cost for coding the skip probability. 110static int FinalizeSkipProba(VP8Encoder* const enc) { 111 VP8EncProba* const proba = &enc->proba_; 112 const int nb_mbs = enc->mb_w_ * enc->mb_h_; 113 const int nb_events = proba->nb_skip_; 114 int size; 115 proba->skip_proba_ = CalcSkipProba(nb_events, nb_mbs); 116 proba->use_skip_proba_ = (proba->skip_proba_ < SKIP_PROBA_THRESHOLD); 117 size = 256; // 'use_skip_proba' bit 118 if (proba->use_skip_proba_) { 119 size += nb_events * VP8BitCost(1, proba->skip_proba_) 120 + (nb_mbs - nb_events) * VP8BitCost(0, proba->skip_proba_); 121 size += 8 * 256; // cost of signaling the skip_proba_ itself. 122 } 123 return size; 124} 125 126// Collect statistics and deduce probabilities for next coding pass. 127// Return the total bit-cost for coding the probability updates. 128static int CalcTokenProba(int nb, int total) { 129 assert(nb <= total); 130 return nb ? (255 - nb * 255 / total) : 255; 131} 132 133// Cost of coding 'nb' 1's and 'total-nb' 0's using 'proba' probability. 134static int BranchCost(int nb, int total, int proba) { 135 return nb * VP8BitCost(1, proba) + (total - nb) * VP8BitCost(0, proba); 136} 137 138static void ResetTokenStats(VP8Encoder* const enc) { 139 VP8EncProba* const proba = &enc->proba_; 140 memset(proba->stats_, 0, sizeof(proba->stats_)); 141} 142 143static int FinalizeTokenProbas(VP8EncProba* const proba) { 144 int has_changed = 0; 145 int size = 0; 146 int t, b, c, p; 147 for (t = 0; t < NUM_TYPES; ++t) { 148 for (b = 0; b < NUM_BANDS; ++b) { 149 for (c = 0; c < NUM_CTX; ++c) { 150 for (p = 0; p < NUM_PROBAS; ++p) { 151 const proba_t stats = proba->stats_[t][b][c][p]; 152 const int nb = (stats >> 0) & 0xffff; 153 const int total = (stats >> 16) & 0xffff; 154 const int update_proba = VP8CoeffsUpdateProba[t][b][c][p]; 155 const int old_p = VP8CoeffsProba0[t][b][c][p]; 156 const int new_p = CalcTokenProba(nb, total); 157 const int old_cost = BranchCost(nb, total, old_p) 158 + VP8BitCost(0, update_proba); 159 const int new_cost = BranchCost(nb, total, new_p) 160 + VP8BitCost(1, update_proba) 161 + 8 * 256; 162 const int use_new_p = (old_cost > new_cost); 163 size += VP8BitCost(use_new_p, update_proba); 164 if (use_new_p) { // only use proba that seem meaningful enough. 165 proba->coeffs_[t][b][c][p] = new_p; 166 has_changed |= (new_p != old_p); 167 size += 8 * 256; 168 } else { 169 proba->coeffs_[t][b][c][p] = old_p; 170 } 171 } 172 } 173 } 174 } 175 proba->dirty_ = has_changed; 176 return size; 177} 178 179//------------------------------------------------------------------------------ 180// Finalize Segment probability based on the coding tree 181 182static int GetProba(int a, int b) { 183 const int total = a + b; 184 return (total == 0) ? 255 // that's the default probability. 185 : (255 * a + total / 2) / total; // rounded proba 186} 187 188static void SetSegmentProbas(VP8Encoder* const enc) { 189 int p[NUM_MB_SEGMENTS] = { 0 }; 190 int n; 191 192 for (n = 0; n < enc->mb_w_ * enc->mb_h_; ++n) { 193 const VP8MBInfo* const mb = &enc->mb_info_[n]; 194 p[mb->segment_]++; 195 } 196 if (enc->pic_->stats != NULL) { 197 for (n = 0; n < NUM_MB_SEGMENTS; ++n) { 198 enc->pic_->stats->segment_size[n] = p[n]; 199 } 200 } 201 if (enc->segment_hdr_.num_segments_ > 1) { 202 uint8_t* const probas = enc->proba_.segments_; 203 probas[0] = GetProba(p[0] + p[1], p[2] + p[3]); 204 probas[1] = GetProba(p[0], p[1]); 205 probas[2] = GetProba(p[2], p[3]); 206 207 enc->segment_hdr_.update_map_ = 208 (probas[0] != 255) || (probas[1] != 255) || (probas[2] != 255); 209 enc->segment_hdr_.size_ = 210 p[0] * (VP8BitCost(0, probas[0]) + VP8BitCost(0, probas[1])) + 211 p[1] * (VP8BitCost(0, probas[0]) + VP8BitCost(1, probas[1])) + 212 p[2] * (VP8BitCost(1, probas[0]) + VP8BitCost(0, probas[2])) + 213 p[3] * (VP8BitCost(1, probas[0]) + VP8BitCost(1, probas[2])); 214 } else { 215 enc->segment_hdr_.update_map_ = 0; 216 enc->segment_hdr_.size_ = 0; 217 } 218} 219 220//------------------------------------------------------------------------------ 221// Coefficient coding 222 223static int PutCoeffs(VP8BitWriter* const bw, int ctx, const VP8Residual* res) { 224 int n = res->first; 225 // should be prob[VP8EncBands[n]], but it's equivalent for n=0 or 1 226 const uint8_t* p = res->prob[n][ctx]; 227 if (!VP8PutBit(bw, res->last >= 0, p[0])) { 228 return 0; 229 } 230 231 while (n < 16) { 232 const int c = res->coeffs[n++]; 233 const int sign = c < 0; 234 int v = sign ? -c : c; 235 if (!VP8PutBit(bw, v != 0, p[1])) { 236 p = res->prob[VP8EncBands[n]][0]; 237 continue; 238 } 239 if (!VP8PutBit(bw, v > 1, p[2])) { 240 p = res->prob[VP8EncBands[n]][1]; 241 } else { 242 if (!VP8PutBit(bw, v > 4, p[3])) { 243 if (VP8PutBit(bw, v != 2, p[4])) 244 VP8PutBit(bw, v == 4, p[5]); 245 } else if (!VP8PutBit(bw, v > 10, p[6])) { 246 if (!VP8PutBit(bw, v > 6, p[7])) { 247 VP8PutBit(bw, v == 6, 159); 248 } else { 249 VP8PutBit(bw, v >= 9, 165); 250 VP8PutBit(bw, !(v & 1), 145); 251 } 252 } else { 253 int mask; 254 const uint8_t* tab; 255 if (v < 3 + (8 << 1)) { // VP8Cat3 (3b) 256 VP8PutBit(bw, 0, p[8]); 257 VP8PutBit(bw, 0, p[9]); 258 v -= 3 + (8 << 0); 259 mask = 1 << 2; 260 tab = VP8Cat3; 261 } else if (v < 3 + (8 << 2)) { // VP8Cat4 (4b) 262 VP8PutBit(bw, 0, p[8]); 263 VP8PutBit(bw, 1, p[9]); 264 v -= 3 + (8 << 1); 265 mask = 1 << 3; 266 tab = VP8Cat4; 267 } else if (v < 3 + (8 << 3)) { // VP8Cat5 (5b) 268 VP8PutBit(bw, 1, p[8]); 269 VP8PutBit(bw, 0, p[10]); 270 v -= 3 + (8 << 2); 271 mask = 1 << 4; 272 tab = VP8Cat5; 273 } else { // VP8Cat6 (11b) 274 VP8PutBit(bw, 1, p[8]); 275 VP8PutBit(bw, 1, p[10]); 276 v -= 3 + (8 << 3); 277 mask = 1 << 10; 278 tab = VP8Cat6; 279 } 280 while (mask) { 281 VP8PutBit(bw, !!(v & mask), *tab++); 282 mask >>= 1; 283 } 284 } 285 p = res->prob[VP8EncBands[n]][2]; 286 } 287 VP8PutBitUniform(bw, sign); 288 if (n == 16 || !VP8PutBit(bw, n <= res->last, p[0])) { 289 return 1; // EOB 290 } 291 } 292 return 1; 293} 294 295static void CodeResiduals(VP8BitWriter* const bw, VP8EncIterator* const it, 296 const VP8ModeScore* const rd) { 297 int x, y, ch; 298 VP8Residual res; 299 uint64_t pos1, pos2, pos3; 300 const int i16 = (it->mb_->type_ == 1); 301 const int segment = it->mb_->segment_; 302 VP8Encoder* const enc = it->enc_; 303 304 VP8IteratorNzToBytes(it); 305 306 pos1 = VP8BitWriterPos(bw); 307 if (i16) { 308 VP8InitResidual(0, 1, enc, &res); 309 VP8SetResidualCoeffs(rd->y_dc_levels, &res); 310 it->top_nz_[8] = it->left_nz_[8] = 311 PutCoeffs(bw, it->top_nz_[8] + it->left_nz_[8], &res); 312 VP8InitResidual(1, 0, enc, &res); 313 } else { 314 VP8InitResidual(0, 3, enc, &res); 315 } 316 317 // luma-AC 318 for (y = 0; y < 4; ++y) { 319 for (x = 0; x < 4; ++x) { 320 const int ctx = it->top_nz_[x] + it->left_nz_[y]; 321 VP8SetResidualCoeffs(rd->y_ac_levels[x + y * 4], &res); 322 it->top_nz_[x] = it->left_nz_[y] = PutCoeffs(bw, ctx, &res); 323 } 324 } 325 pos2 = VP8BitWriterPos(bw); 326 327 // U/V 328 VP8InitResidual(0, 2, enc, &res); 329 for (ch = 0; ch <= 2; ch += 2) { 330 for (y = 0; y < 2; ++y) { 331 for (x = 0; x < 2; ++x) { 332 const int ctx = it->top_nz_[4 + ch + x] + it->left_nz_[4 + ch + y]; 333 VP8SetResidualCoeffs(rd->uv_levels[ch * 2 + x + y * 2], &res); 334 it->top_nz_[4 + ch + x] = it->left_nz_[4 + ch + y] = 335 PutCoeffs(bw, ctx, &res); 336 } 337 } 338 } 339 pos3 = VP8BitWriterPos(bw); 340 it->luma_bits_ = pos2 - pos1; 341 it->uv_bits_ = pos3 - pos2; 342 it->bit_count_[segment][i16] += it->luma_bits_; 343 it->bit_count_[segment][2] += it->uv_bits_; 344 VP8IteratorBytesToNz(it); 345} 346 347// Same as CodeResiduals, but doesn't actually write anything. 348// Instead, it just records the event distribution. 349static void RecordResiduals(VP8EncIterator* const it, 350 const VP8ModeScore* const rd) { 351 int x, y, ch; 352 VP8Residual res; 353 VP8Encoder* const enc = it->enc_; 354 355 VP8IteratorNzToBytes(it); 356 357 if (it->mb_->type_ == 1) { // i16x16 358 VP8InitResidual(0, 1, enc, &res); 359 VP8SetResidualCoeffs(rd->y_dc_levels, &res); 360 it->top_nz_[8] = it->left_nz_[8] = 361 VP8RecordCoeffs(it->top_nz_[8] + it->left_nz_[8], &res); 362 VP8InitResidual(1, 0, enc, &res); 363 } else { 364 VP8InitResidual(0, 3, enc, &res); 365 } 366 367 // luma-AC 368 for (y = 0; y < 4; ++y) { 369 for (x = 0; x < 4; ++x) { 370 const int ctx = it->top_nz_[x] + it->left_nz_[y]; 371 VP8SetResidualCoeffs(rd->y_ac_levels[x + y * 4], &res); 372 it->top_nz_[x] = it->left_nz_[y] = VP8RecordCoeffs(ctx, &res); 373 } 374 } 375 376 // U/V 377 VP8InitResidual(0, 2, enc, &res); 378 for (ch = 0; ch <= 2; ch += 2) { 379 for (y = 0; y < 2; ++y) { 380 for (x = 0; x < 2; ++x) { 381 const int ctx = it->top_nz_[4 + ch + x] + it->left_nz_[4 + ch + y]; 382 VP8SetResidualCoeffs(rd->uv_levels[ch * 2 + x + y * 2], &res); 383 it->top_nz_[4 + ch + x] = it->left_nz_[4 + ch + y] = 384 VP8RecordCoeffs(ctx, &res); 385 } 386 } 387 } 388 389 VP8IteratorBytesToNz(it); 390} 391 392//------------------------------------------------------------------------------ 393// Token buffer 394 395#if !defined(DISABLE_TOKEN_BUFFER) 396 397static int RecordTokens(VP8EncIterator* const it, const VP8ModeScore* const rd, 398 VP8TBuffer* const tokens) { 399 int x, y, ch; 400 VP8Residual res; 401 VP8Encoder* const enc = it->enc_; 402 403 VP8IteratorNzToBytes(it); 404 if (it->mb_->type_ == 1) { // i16x16 405 const int ctx = it->top_nz_[8] + it->left_nz_[8]; 406 VP8InitResidual(0, 1, enc, &res); 407 VP8SetResidualCoeffs(rd->y_dc_levels, &res); 408 it->top_nz_[8] = it->left_nz_[8] = 409 VP8RecordCoeffTokens(ctx, 1, 410 res.first, res.last, res.coeffs, tokens); 411 VP8RecordCoeffs(ctx, &res); 412 VP8InitResidual(1, 0, enc, &res); 413 } else { 414 VP8InitResidual(0, 3, enc, &res); 415 } 416 417 // luma-AC 418 for (y = 0; y < 4; ++y) { 419 for (x = 0; x < 4; ++x) { 420 const int ctx = it->top_nz_[x] + it->left_nz_[y]; 421 VP8SetResidualCoeffs(rd->y_ac_levels[x + y * 4], &res); 422 it->top_nz_[x] = it->left_nz_[y] = 423 VP8RecordCoeffTokens(ctx, res.coeff_type, 424 res.first, res.last, res.coeffs, tokens); 425 VP8RecordCoeffs(ctx, &res); 426 } 427 } 428 429 // U/V 430 VP8InitResidual(0, 2, enc, &res); 431 for (ch = 0; ch <= 2; ch += 2) { 432 for (y = 0; y < 2; ++y) { 433 for (x = 0; x < 2; ++x) { 434 const int ctx = it->top_nz_[4 + ch + x] + it->left_nz_[4 + ch + y]; 435 VP8SetResidualCoeffs(rd->uv_levels[ch * 2 + x + y * 2], &res); 436 it->top_nz_[4 + ch + x] = it->left_nz_[4 + ch + y] = 437 VP8RecordCoeffTokens(ctx, 2, 438 res.first, res.last, res.coeffs, tokens); 439 VP8RecordCoeffs(ctx, &res); 440 } 441 } 442 } 443 VP8IteratorBytesToNz(it); 444 return !tokens->error_; 445} 446 447#endif // !DISABLE_TOKEN_BUFFER 448 449//------------------------------------------------------------------------------ 450// ExtraInfo map / Debug function 451 452#if SEGMENT_VISU 453static void SetBlock(uint8_t* p, int value, int size) { 454 int y; 455 for (y = 0; y < size; ++y) { 456 memset(p, value, size); 457 p += BPS; 458 } 459} 460#endif 461 462static void ResetSSE(VP8Encoder* const enc) { 463 enc->sse_[0] = 0; 464 enc->sse_[1] = 0; 465 enc->sse_[2] = 0; 466 // Note: enc->sse_[3] is managed by alpha.c 467 enc->sse_count_ = 0; 468} 469 470static void StoreSSE(const VP8EncIterator* const it) { 471 VP8Encoder* const enc = it->enc_; 472 const uint8_t* const in = it->yuv_in_; 473 const uint8_t* const out = it->yuv_out_; 474 // Note: not totally accurate at boundary. And doesn't include in-loop filter. 475 enc->sse_[0] += VP8SSE16x16(in + Y_OFF_ENC, out + Y_OFF_ENC); 476 enc->sse_[1] += VP8SSE8x8(in + U_OFF_ENC, out + U_OFF_ENC); 477 enc->sse_[2] += VP8SSE8x8(in + V_OFF_ENC, out + V_OFF_ENC); 478 enc->sse_count_ += 16 * 16; 479} 480 481static void StoreSideInfo(const VP8EncIterator* const it) { 482 VP8Encoder* const enc = it->enc_; 483 const VP8MBInfo* const mb = it->mb_; 484 WebPPicture* const pic = enc->pic_; 485 486 if (pic->stats != NULL) { 487 StoreSSE(it); 488 enc->block_count_[0] += (mb->type_ == 0); 489 enc->block_count_[1] += (mb->type_ == 1); 490 enc->block_count_[2] += (mb->skip_ != 0); 491 } 492 493 if (pic->extra_info != NULL) { 494 uint8_t* const info = &pic->extra_info[it->x_ + it->y_ * enc->mb_w_]; 495 switch (pic->extra_info_type) { 496 case 1: *info = mb->type_; break; 497 case 2: *info = mb->segment_; break; 498 case 3: *info = enc->dqm_[mb->segment_].quant_; break; 499 case 4: *info = (mb->type_ == 1) ? it->preds_[0] : 0xff; break; 500 case 5: *info = mb->uv_mode_; break; 501 case 6: { 502 const int b = (int)((it->luma_bits_ + it->uv_bits_ + 7) >> 3); 503 *info = (b > 255) ? 255 : b; break; 504 } 505 case 7: *info = mb->alpha_; break; 506 default: *info = 0; break; 507 } 508 } 509#if SEGMENT_VISU // visualize segments and prediction modes 510 SetBlock(it->yuv_out_ + Y_OFF_ENC, mb->segment_ * 64, 16); 511 SetBlock(it->yuv_out_ + U_OFF_ENC, it->preds_[0] * 64, 8); 512 SetBlock(it->yuv_out_ + V_OFF_ENC, mb->uv_mode_ * 64, 8); 513#endif 514} 515 516static double GetPSNR(uint64_t mse, uint64_t size) { 517 return (mse > 0 && size > 0) ? 10. * log10(255. * 255. * size / mse) : 99; 518} 519 520//------------------------------------------------------------------------------ 521// StatLoop(): only collect statistics (number of skips, token usage, ...). 522// This is used for deciding optimal probabilities. It also modifies the 523// quantizer value if some target (size, PSNR) was specified. 524 525static void SetLoopParams(VP8Encoder* const enc, float q) { 526 // Make sure the quality parameter is inside valid bounds 527 q = Clamp(q, 0.f, 100.f); 528 529 VP8SetSegmentParams(enc, q); // setup segment quantizations and filters 530 SetSegmentProbas(enc); // compute segment probabilities 531 532 ResetStats(enc); 533 ResetSSE(enc); 534} 535 536static uint64_t OneStatPass(VP8Encoder* const enc, VP8RDLevel rd_opt, 537 int nb_mbs, int percent_delta, 538 PassStats* const s) { 539 VP8EncIterator it; 540 uint64_t size = 0; 541 uint64_t size_p0 = 0; 542 uint64_t distortion = 0; 543 const uint64_t pixel_count = nb_mbs * 384; 544 545 VP8IteratorInit(enc, &it); 546 SetLoopParams(enc, s->q); 547 do { 548 VP8ModeScore info; 549 VP8IteratorImport(&it, NULL); 550 if (VP8Decimate(&it, &info, rd_opt)) { 551 // Just record the number of skips and act like skip_proba is not used. 552 enc->proba_.nb_skip_++; 553 } 554 RecordResiduals(&it, &info); 555 size += info.R + info.H; 556 size_p0 += info.H; 557 distortion += info.D; 558 if (percent_delta && !VP8IteratorProgress(&it, percent_delta)) 559 return 0; 560 VP8IteratorSaveBoundary(&it); 561 } while (VP8IteratorNext(&it) && --nb_mbs > 0); 562 563 size_p0 += enc->segment_hdr_.size_; 564 if (s->do_size_search) { 565 size += FinalizeSkipProba(enc); 566 size += FinalizeTokenProbas(&enc->proba_); 567 size = ((size + size_p0 + 1024) >> 11) + HEADER_SIZE_ESTIMATE; 568 s->value = (double)size; 569 } else { 570 s->value = GetPSNR(distortion, pixel_count); 571 } 572 return size_p0; 573} 574 575static int StatLoop(VP8Encoder* const enc) { 576 const int method = enc->method_; 577 const int do_search = enc->do_search_; 578 const int fast_probe = ((method == 0 || method == 3) && !do_search); 579 int num_pass_left = enc->config_->pass; 580 const int task_percent = 20; 581 const int percent_per_pass = 582 (task_percent + num_pass_left / 2) / num_pass_left; 583 const int final_percent = enc->percent_ + task_percent; 584 const VP8RDLevel rd_opt = 585 (method >= 3 || do_search) ? RD_OPT_BASIC : RD_OPT_NONE; 586 int nb_mbs = enc->mb_w_ * enc->mb_h_; 587 PassStats stats; 588 589 InitPassStats(enc, &stats); 590 ResetTokenStats(enc); 591 592 // Fast mode: quick analysis pass over few mbs. Better than nothing. 593 if (fast_probe) { 594 if (method == 3) { // we need more stats for method 3 to be reliable. 595 nb_mbs = (nb_mbs > 200) ? nb_mbs >> 1 : 100; 596 } else { 597 nb_mbs = (nb_mbs > 200) ? nb_mbs >> 2 : 50; 598 } 599 } 600 601 while (num_pass_left-- > 0) { 602 const int is_last_pass = (fabs(stats.dq) <= DQ_LIMIT) || 603 (num_pass_left == 0) || 604 (enc->max_i4_header_bits_ == 0); 605 const uint64_t size_p0 = 606 OneStatPass(enc, rd_opt, nb_mbs, percent_per_pass, &stats); 607 if (size_p0 == 0) return 0; 608#if (DEBUG_SEARCH > 0) 609 printf("#%d value:%.1lf -> %.1lf q:%.2f -> %.2f\n", 610 num_pass_left, stats.last_value, stats.value, stats.last_q, stats.q); 611#endif 612 if (enc->max_i4_header_bits_ > 0 && size_p0 > PARTITION0_SIZE_LIMIT) { 613 ++num_pass_left; 614 enc->max_i4_header_bits_ >>= 1; // strengthen header bit limitation... 615 continue; // ...and start over 616 } 617 if (is_last_pass) { 618 break; 619 } 620 // If no target size: just do several pass without changing 'q' 621 if (do_search) { 622 ComputeNextQ(&stats); 623 if (fabs(stats.dq) <= DQ_LIMIT) break; 624 } 625 } 626 if (!do_search || !stats.do_size_search) { 627 // Need to finalize probas now, since it wasn't done during the search. 628 FinalizeSkipProba(enc); 629 FinalizeTokenProbas(&enc->proba_); 630 } 631 VP8CalculateLevelCosts(&enc->proba_); // finalize costs 632 return WebPReportProgress(enc->pic_, final_percent, &enc->percent_); 633} 634 635//------------------------------------------------------------------------------ 636// Main loops 637// 638 639static const int kAverageBytesPerMB[8] = { 50, 24, 16, 9, 7, 5, 3, 2 }; 640 641static int PreLoopInitialize(VP8Encoder* const enc) { 642 int p; 643 int ok = 1; 644 const int average_bytes_per_MB = kAverageBytesPerMB[enc->base_quant_ >> 4]; 645 const int bytes_per_parts = 646 enc->mb_w_ * enc->mb_h_ * average_bytes_per_MB / enc->num_parts_; 647 // Initialize the bit-writers 648 for (p = 0; ok && p < enc->num_parts_; ++p) { 649 ok = VP8BitWriterInit(enc->parts_ + p, bytes_per_parts); 650 } 651 if (!ok) { 652 VP8EncFreeBitWriters(enc); // malloc error occurred 653 WebPEncodingSetError(enc->pic_, VP8_ENC_ERROR_OUT_OF_MEMORY); 654 } 655 return ok; 656} 657 658static int PostLoopFinalize(VP8EncIterator* const it, int ok) { 659 VP8Encoder* const enc = it->enc_; 660 if (ok) { // Finalize the partitions, check for extra errors. 661 int p; 662 for (p = 0; p < enc->num_parts_; ++p) { 663 VP8BitWriterFinish(enc->parts_ + p); 664 ok &= !enc->parts_[p].error_; 665 } 666 } 667 668 if (ok) { // All good. Finish up. 669 if (enc->pic_->stats != NULL) { // finalize byte counters... 670 int i, s; 671 for (i = 0; i <= 2; ++i) { 672 for (s = 0; s < NUM_MB_SEGMENTS; ++s) { 673 enc->residual_bytes_[i][s] = (int)((it->bit_count_[s][i] + 7) >> 3); 674 } 675 } 676 } 677 VP8AdjustFilterStrength(it); // ...and store filter stats. 678 } else { 679 // Something bad happened -> need to do some memory cleanup. 680 VP8EncFreeBitWriters(enc); 681 } 682 return ok; 683} 684 685//------------------------------------------------------------------------------ 686// VP8EncLoop(): does the final bitstream coding. 687 688static void ResetAfterSkip(VP8EncIterator* const it) { 689 if (it->mb_->type_ == 1) { 690 *it->nz_ = 0; // reset all predictors 691 it->left_nz_[8] = 0; 692 } else { 693 *it->nz_ &= (1 << 24); // preserve the dc_nz bit 694 } 695} 696 697int VP8EncLoop(VP8Encoder* const enc) { 698 VP8EncIterator it; 699 int ok = PreLoopInitialize(enc); 700 if (!ok) return 0; 701 702 StatLoop(enc); // stats-collection loop 703 704 VP8IteratorInit(enc, &it); 705 VP8InitFilter(&it); 706 do { 707 VP8ModeScore info; 708 const int dont_use_skip = !enc->proba_.use_skip_proba_; 709 const VP8RDLevel rd_opt = enc->rd_opt_level_; 710 711 VP8IteratorImport(&it, NULL); 712 // Warning! order is important: first call VP8Decimate() and 713 // *then* decide how to code the skip decision if there's one. 714 if (!VP8Decimate(&it, &info, rd_opt) || dont_use_skip) { 715 CodeResiduals(it.bw_, &it, &info); 716 } else { // reset predictors after a skip 717 ResetAfterSkip(&it); 718 } 719 StoreSideInfo(&it); 720 VP8StoreFilterStats(&it); 721 VP8IteratorExport(&it); 722 ok = VP8IteratorProgress(&it, 20); 723 VP8IteratorSaveBoundary(&it); 724 } while (ok && VP8IteratorNext(&it)); 725 726 return PostLoopFinalize(&it, ok); 727} 728 729//------------------------------------------------------------------------------ 730// Single pass using Token Buffer. 731 732#if !defined(DISABLE_TOKEN_BUFFER) 733 734#define MIN_COUNT 96 // minimum number of macroblocks before updating stats 735 736int VP8EncTokenLoop(VP8Encoder* const enc) { 737 // Roughly refresh the proba eight times per pass 738 int max_count = (enc->mb_w_ * enc->mb_h_) >> 3; 739 int num_pass_left = enc->config_->pass; 740 const int do_search = enc->do_search_; 741 VP8EncIterator it; 742 VP8EncProba* const proba = &enc->proba_; 743 const VP8RDLevel rd_opt = enc->rd_opt_level_; 744 const uint64_t pixel_count = enc->mb_w_ * enc->mb_h_ * 384; 745 PassStats stats; 746 int ok; 747 748 InitPassStats(enc, &stats); 749 ok = PreLoopInitialize(enc); 750 if (!ok) return 0; 751 752 if (max_count < MIN_COUNT) max_count = MIN_COUNT; 753 754 assert(enc->num_parts_ == 1); 755 assert(enc->use_tokens_); 756 assert(proba->use_skip_proba_ == 0); 757 assert(rd_opt >= RD_OPT_BASIC); // otherwise, token-buffer won't be useful 758 assert(num_pass_left > 0); 759 760 while (ok && num_pass_left-- > 0) { 761 const int is_last_pass = (fabs(stats.dq) <= DQ_LIMIT) || 762 (num_pass_left == 0) || 763 (enc->max_i4_header_bits_ == 0); 764 uint64_t size_p0 = 0; 765 uint64_t distortion = 0; 766 int cnt = max_count; 767 VP8IteratorInit(enc, &it); 768 SetLoopParams(enc, stats.q); 769 if (is_last_pass) { 770 ResetTokenStats(enc); 771 VP8InitFilter(&it); // don't collect stats until last pass (too costly) 772 } 773 VP8TBufferClear(&enc->tokens_); 774 do { 775 VP8ModeScore info; 776 VP8IteratorImport(&it, NULL); 777 if (--cnt < 0) { 778 FinalizeTokenProbas(proba); 779 VP8CalculateLevelCosts(proba); // refresh cost tables for rd-opt 780 cnt = max_count; 781 } 782 VP8Decimate(&it, &info, rd_opt); 783 ok = RecordTokens(&it, &info, &enc->tokens_); 784 if (!ok) { 785 WebPEncodingSetError(enc->pic_, VP8_ENC_ERROR_OUT_OF_MEMORY); 786 break; 787 } 788 size_p0 += info.H; 789 distortion += info.D; 790 if (is_last_pass) { 791 StoreSideInfo(&it); 792 VP8StoreFilterStats(&it); 793 VP8IteratorExport(&it); 794 ok = VP8IteratorProgress(&it, 20); 795 } 796 VP8IteratorSaveBoundary(&it); 797 } while (ok && VP8IteratorNext(&it)); 798 if (!ok) break; 799 800 size_p0 += enc->segment_hdr_.size_; 801 if (stats.do_size_search) { 802 uint64_t size = FinalizeTokenProbas(&enc->proba_); 803 size += VP8EstimateTokenSize(&enc->tokens_, 804 (const uint8_t*)proba->coeffs_); 805 size = (size + size_p0 + 1024) >> 11; // -> size in bytes 806 size += HEADER_SIZE_ESTIMATE; 807 stats.value = (double)size; 808 } else { // compute and store PSNR 809 stats.value = GetPSNR(distortion, pixel_count); 810 } 811 812#if (DEBUG_SEARCH > 0) 813 printf("#%2d metric:%.1lf -> %.1lf last_q=%.2lf q=%.2lf dq=%.2lf\n", 814 num_pass_left, stats.last_value, stats.value, 815 stats.last_q, stats.q, stats.dq); 816#endif 817 if (size_p0 > PARTITION0_SIZE_LIMIT) { 818 ++num_pass_left; 819 enc->max_i4_header_bits_ >>= 1; // strengthen header bit limitation... 820 continue; // ...and start over 821 } 822 if (is_last_pass) { 823 break; // done 824 } 825 if (do_search) { 826 ComputeNextQ(&stats); // Adjust q 827 } 828 } 829 if (ok) { 830 if (!stats.do_size_search) { 831 FinalizeTokenProbas(&enc->proba_); 832 } 833 ok = VP8EmitTokens(&enc->tokens_, enc->parts_ + 0, 834 (const uint8_t*)proba->coeffs_, 1); 835 } 836 ok = ok && WebPReportProgress(enc->pic_, enc->percent_ + 20, &enc->percent_); 837 return PostLoopFinalize(&it, ok); 838} 839 840#else 841 842int VP8EncTokenLoop(VP8Encoder* const enc) { 843 (void)enc; 844 return 0; // we shouldn't be here. 845} 846 847#endif // DISABLE_TOKEN_BUFFER 848 849//------------------------------------------------------------------------------ 850 851