vp8enci.h revision 2a99a7e74a7f215066514fe81d2bfa6639d9eddd
1// Copyright 2011 Google Inc. All Rights Reserved. 2// 3// This code is licensed under the same terms as WebM: 4// Software License Agreement: http://www.webmproject.org/license/software/ 5// Additional IP Rights Grant: http://www.webmproject.org/license/additional/ 6// ----------------------------------------------------------------------------- 7// 8// WebP encoder: internal header. 9// 10// Author: Skal (pascal.massimino@gmail.com) 11 12#ifndef WEBP_ENC_VP8ENCI_H_ 13#define WEBP_ENC_VP8ENCI_H_ 14 15#include <string.h> // for memcpy() 16#include "../webp/encode.h" 17#include "../dsp/dsp.h" 18#include "../utils/bit_writer.h" 19#include "../utils/thread.h" 20 21#if defined(__cplusplus) || defined(c_plusplus) 22extern "C" { 23#endif 24 25//------------------------------------------------------------------------------ 26// Various defines and enums 27 28// version numbers 29#define ENC_MAJ_VERSION 0 30#define ENC_MIN_VERSION 3 31#define ENC_REV_VERSION 0 32 33// intra prediction modes 34enum { B_DC_PRED = 0, // 4x4 modes 35 B_TM_PRED = 1, 36 B_VE_PRED = 2, 37 B_HE_PRED = 3, 38 B_RD_PRED = 4, 39 B_VR_PRED = 5, 40 B_LD_PRED = 6, 41 B_VL_PRED = 7, 42 B_HD_PRED = 8, 43 B_HU_PRED = 9, 44 NUM_BMODES = B_HU_PRED + 1 - B_DC_PRED, // = 10 45 46 // Luma16 or UV modes 47 DC_PRED = B_DC_PRED, V_PRED = B_VE_PRED, 48 H_PRED = B_HE_PRED, TM_PRED = B_TM_PRED, 49 NUM_PRED_MODES = 4 50 }; 51 52enum { NUM_MB_SEGMENTS = 4, 53 MAX_NUM_PARTITIONS = 8, 54 NUM_TYPES = 4, // 0: i16-AC, 1: i16-DC, 2:chroma-AC, 3:i4-AC 55 NUM_BANDS = 8, 56 NUM_CTX = 3, 57 NUM_PROBAS = 11, 58 MAX_LF_LEVELS = 64, // Maximum loop filter level 59 MAX_VARIABLE_LEVEL = 67 // last (inclusive) level with variable cost 60 }; 61 62typedef enum { // Rate-distortion optimization levels 63 RD_OPT_NONE = 0, // no rd-opt 64 RD_OPT_BASIC = 1, // basic scoring (no trellis) 65 RD_OPT_TRELLIS = 2, // perform trellis-quant on the final decision only 66 RD_OPT_TRELLIS_ALL = 3 // trellis-quant for every scoring (much slower) 67} VP8RDLevel; 68 69// YUV-cache parameters. Cache is 16-pixels wide. 70// The original or reconstructed samples can be accessed using VP8Scan[] 71// The predicted blocks can be accessed using offsets to yuv_p_ and 72// the arrays VP8*ModeOffsets[]; 73// +----+ YUV Samples area. See VP8Scan[] for accessing the blocks. 74// Y_OFF |YYYY| <- original samples (enc->yuv_in_) 75// |YYYY| 76// |YYYY| 77// |YYYY| 78// U_OFF |UUVV| V_OFF (=U_OFF + 8) 79// |UUVV| 80// +----+ 81// Y_OFF |YYYY| <- compressed/decoded samples ('yuv_out_') 82// |YYYY| There are two buffers like this ('yuv_out_'/'yuv_out2_') 83// |YYYY| 84// |YYYY| 85// U_OFF |UUVV| V_OFF 86// |UUVV| 87// x2 (for yuv_out2_) 88// +----+ Prediction area ('yuv_p_', size = PRED_SIZE) 89// I16DC16 |YYYY| Intra16 predictions (16x16 block each) 90// |YYYY| 91// |YYYY| 92// |YYYY| 93// I16TM16 |YYYY| 94// |YYYY| 95// |YYYY| 96// |YYYY| 97// I16VE16 |YYYY| 98// |YYYY| 99// |YYYY| 100// |YYYY| 101// I16HE16 |YYYY| 102// |YYYY| 103// |YYYY| 104// |YYYY| 105// +----+ Chroma U/V predictions (16x8 block each) 106// C8DC8 |UUVV| 107// |UUVV| 108// C8TM8 |UUVV| 109// |UUVV| 110// C8VE8 |UUVV| 111// |UUVV| 112// C8HE8 |UUVV| 113// |UUVV| 114// +----+ Intra 4x4 predictions (4x4 block each) 115// |YYYY| I4DC4 I4TM4 I4VE4 I4HE4 116// |YYYY| I4RD4 I4VR4 I4LD4 I4VL4 117// |YY..| I4HD4 I4HU4 I4TMP 118// +----+ 119#define BPS 16 // this is the common stride 120#define Y_SIZE (BPS * 16) 121#define UV_SIZE (BPS * 8) 122#define YUV_SIZE (Y_SIZE + UV_SIZE) 123#define PRED_SIZE (6 * 16 * BPS + 12 * BPS) 124#define Y_OFF (0) 125#define U_OFF (Y_SIZE) 126#define V_OFF (U_OFF + 8) 127#define ALIGN_CST 15 128#define DO_ALIGN(PTR) ((uintptr_t)((PTR) + ALIGN_CST) & ~ALIGN_CST) 129 130extern const int VP8Scan[16 + 4 + 4]; // in quant.c 131extern const int VP8UVModeOffsets[4]; // in analyze.c 132extern const int VP8I16ModeOffsets[4]; 133extern const int VP8I4ModeOffsets[NUM_BMODES]; 134 135// Layout of prediction blocks 136// intra 16x16 137#define I16DC16 (0 * 16 * BPS) 138#define I16TM16 (1 * 16 * BPS) 139#define I16VE16 (2 * 16 * BPS) 140#define I16HE16 (3 * 16 * BPS) 141// chroma 8x8, two U/V blocks side by side (hence: 16x8 each) 142#define C8DC8 (4 * 16 * BPS) 143#define C8TM8 (4 * 16 * BPS + 8 * BPS) 144#define C8VE8 (5 * 16 * BPS) 145#define C8HE8 (5 * 16 * BPS + 8 * BPS) 146// intra 4x4 147#define I4DC4 (6 * 16 * BPS + 0) 148#define I4TM4 (6 * 16 * BPS + 4) 149#define I4VE4 (6 * 16 * BPS + 8) 150#define I4HE4 (6 * 16 * BPS + 12) 151#define I4RD4 (6 * 16 * BPS + 4 * BPS + 0) 152#define I4VR4 (6 * 16 * BPS + 4 * BPS + 4) 153#define I4LD4 (6 * 16 * BPS + 4 * BPS + 8) 154#define I4VL4 (6 * 16 * BPS + 4 * BPS + 12) 155#define I4HD4 (6 * 16 * BPS + 8 * BPS + 0) 156#define I4HU4 (6 * 16 * BPS + 8 * BPS + 4) 157#define I4TMP (6 * 16 * BPS + 8 * BPS + 8) 158 159typedef int64_t score_t; // type used for scores, rate, distortion 160#define MAX_COST ((score_t)0x7fffffffffffffLL) 161 162#define QFIX 17 163#define BIAS(b) ((b) << (QFIX - 8)) 164// Fun fact: this is the _only_ line where we're actually being lossy and 165// discarding bits. 166static WEBP_INLINE int QUANTDIV(int n, int iQ, int B) { 167 return (n * iQ + B) >> QFIX; 168} 169 170// size of histogram used by CollectHistogram. 171#define MAX_COEFF_THRESH 31 172typedef struct VP8Histogram VP8Histogram; 173struct VP8Histogram { 174 // TODO(skal): we only need to store the max_value and last_non_zero actually. 175 int distribution[MAX_COEFF_THRESH + 1]; 176}; 177 178// Uncomment the following to remove token-buffer code: 179// #define DISABLE_TOKEN_BUFFER 180 181//------------------------------------------------------------------------------ 182// Headers 183 184typedef uint32_t proba_t; // 16b + 16b 185typedef uint8_t ProbaArray[NUM_CTX][NUM_PROBAS]; 186typedef proba_t StatsArray[NUM_CTX][NUM_PROBAS]; 187typedef uint16_t CostArray[NUM_CTX][MAX_VARIABLE_LEVEL + 1]; 188typedef double LFStats[NUM_MB_SEGMENTS][MAX_LF_LEVELS]; // filter stats 189 190typedef struct VP8Encoder VP8Encoder; 191 192// segment features 193typedef struct { 194 int num_segments_; // Actual number of segments. 1 segment only = unused. 195 int update_map_; // whether to update the segment map or not. 196 // must be 0 if there's only 1 segment. 197 int size_; // bit-cost for transmitting the segment map 198} VP8SegmentHeader; 199 200// Struct collecting all frame-persistent probabilities. 201typedef struct { 202 uint8_t segments_[3]; // probabilities for segment tree 203 uint8_t skip_proba_; // final probability of being skipped. 204 ProbaArray coeffs_[NUM_TYPES][NUM_BANDS]; // 924 bytes 205 StatsArray stats_[NUM_TYPES][NUM_BANDS]; // 4224 bytes 206 CostArray level_cost_[NUM_TYPES][NUM_BANDS]; // 11.4k 207 int dirty_; // if true, need to call VP8CalculateLevelCosts() 208 int use_skip_proba_; // Note: we always use skip_proba for now. 209 int nb_skip_; // number of skipped blocks 210} VP8Proba; 211 212// Filter parameters. Not actually used in the code (we don't perform 213// the in-loop filtering), but filled from user's config 214typedef struct { 215 int simple_; // filtering type: 0=complex, 1=simple 216 int level_; // base filter level [0..63] 217 int sharpness_; // [0..7] 218 int i4x4_lf_delta_; // delta filter level for i4x4 relative to i16x16 219} VP8FilterHeader; 220 221//------------------------------------------------------------------------------ 222// Informations about the macroblocks. 223 224typedef struct { 225 // block type 226 unsigned int type_:2; // 0=i4x4, 1=i16x16 227 unsigned int uv_mode_:2; 228 unsigned int skip_:1; 229 unsigned int segment_:2; 230 uint8_t alpha_; // quantization-susceptibility 231} VP8MBInfo; 232 233typedef struct VP8Matrix { 234 uint16_t q_[16]; // quantizer steps 235 uint16_t iq_[16]; // reciprocals, fixed point. 236 uint16_t bias_[16]; // rounding bias 237 uint16_t zthresh_[16]; // value under which a coefficient is zeroed 238 uint16_t sharpen_[16]; // frequency boosters for slight sharpening 239} VP8Matrix; 240 241typedef struct { 242 VP8Matrix y1_, y2_, uv_; // quantization matrices 243 int alpha_; // quant-susceptibility, range [-127,127]. Zero is neutral. 244 // Lower values indicate a lower risk of blurriness. 245 int beta_; // filter-susceptibility, range [0,255]. 246 int quant_; // final segment quantizer. 247 int fstrength_; // final in-loop filtering strength 248 // reactivities 249 int lambda_i16_, lambda_i4_, lambda_uv_; 250 int lambda_mode_, lambda_trellis_, tlambda_; 251 int lambda_trellis_i16_, lambda_trellis_i4_, lambda_trellis_uv_; 252} VP8SegmentInfo; 253 254// Handy transcient struct to accumulate score and info during RD-optimization 255// and mode evaluation. 256typedef struct { 257 score_t D, SD, R, score; // Distortion, spectral distortion, rate, score. 258 int16_t y_dc_levels[16]; // Quantized levels for luma-DC, luma-AC, chroma. 259 int16_t y_ac_levels[16][16]; 260 int16_t uv_levels[4 + 4][16]; 261 int mode_i16; // mode number for intra16 prediction 262 uint8_t modes_i4[16]; // mode numbers for intra4 predictions 263 int mode_uv; // mode number of chroma prediction 264 uint32_t nz; // non-zero blocks 265} VP8ModeScore; 266 267// Iterator structure to iterate through macroblocks, pointing to the 268// right neighbouring data (samples, predictions, contexts, ...) 269typedef struct { 270 int x_, y_; // current macroblock 271 int y_offset_, uv_offset_; // offset to the luma / chroma planes 272 int y_stride_, uv_stride_; // respective strides 273 uint8_t* yuv_in_; // borrowed from enc_ (for now) 274 uint8_t* yuv_out_; // '' 275 uint8_t* yuv_out2_; // '' 276 uint8_t* yuv_p_; // '' 277 VP8Encoder* enc_; // back-pointer 278 VP8MBInfo* mb_; // current macroblock 279 VP8BitWriter* bw_; // current bit-writer 280 uint8_t* preds_; // intra mode predictors (4x4 blocks) 281 uint32_t* nz_; // non-zero pattern 282 uint8_t i4_boundary_[37]; // 32+5 boundary samples needed by intra4x4 283 uint8_t* i4_top_; // pointer to the current top boundary sample 284 int i4_; // current intra4x4 mode being tested 285 int top_nz_[9]; // top-non-zero context. 286 int left_nz_[9]; // left-non-zero. left_nz[8] is independent. 287 uint64_t bit_count_[4][3]; // bit counters for coded levels. 288 uint64_t luma_bits_; // macroblock bit-cost for luma 289 uint64_t uv_bits_; // macroblock bit-cost for chroma 290 LFStats* lf_stats_; // filter stats (borrowed from enc_) 291 int do_trellis_; // if true, perform extra level optimisation 292 int done_; // true when scan is finished 293 int percent0_; // saved initial progress percent 294} VP8EncIterator; 295 296 // in iterator.c 297// must be called first. 298void VP8IteratorInit(VP8Encoder* const enc, VP8EncIterator* const it); 299// restart a scan. 300void VP8IteratorReset(VP8EncIterator* const it); 301// import samples from source 302void VP8IteratorImport(const VP8EncIterator* const it); 303// export decimated samples 304void VP8IteratorExport(const VP8EncIterator* const it); 305// go to next macroblock. Returns !done_. If *block_to_save is non-null, will 306// save the boundary values to top_/left_ arrays. block_to_save can be 307// it->yuv_out_ or it->yuv_in_. 308int VP8IteratorNext(VP8EncIterator* const it, 309 const uint8_t* const block_to_save); 310// Report progression based on macroblock rows. Return 0 for user-abort request. 311int VP8IteratorProgress(const VP8EncIterator* const it, 312 int final_delta_percent); 313// Intra4x4 iterations 314void VP8IteratorStartI4(VP8EncIterator* const it); 315// returns true if not done. 316int VP8IteratorRotateI4(VP8EncIterator* const it, 317 const uint8_t* const yuv_out); 318 319// Non-zero context setup/teardown 320void VP8IteratorNzToBytes(VP8EncIterator* const it); 321void VP8IteratorBytesToNz(VP8EncIterator* const it); 322 323// Helper functions to set mode properties 324void VP8SetIntra16Mode(const VP8EncIterator* const it, int mode); 325void VP8SetIntra4Mode(const VP8EncIterator* const it, const uint8_t* modes); 326void VP8SetIntraUVMode(const VP8EncIterator* const it, int mode); 327void VP8SetSkip(const VP8EncIterator* const it, int skip); 328void VP8SetSegment(const VP8EncIterator* const it, int segment); 329 330//------------------------------------------------------------------------------ 331// Paginated token buffer 332 333typedef struct VP8Tokens VP8Tokens; // struct details in token.c 334 335typedef struct { 336#if !defined(DISABLE_TOKEN_BUFFER) 337 VP8Tokens* pages_; // first page 338 VP8Tokens** last_page_; // last page 339 uint16_t* tokens_; // set to (*last_page_)->tokens_ 340 int left_; // how many free tokens left before the page is full. 341#endif 342 int error_; // true in case of malloc error 343} VP8TBuffer; 344 345void VP8TBufferInit(VP8TBuffer* const b); // initialize an empty buffer 346void VP8TBufferClear(VP8TBuffer* const b); // de-allocate pages memory 347 348#if !defined(DISABLE_TOKEN_BUFFER) 349 350// Finalizes bitstream when probabilities are known. 351// Deletes the allocated token memory if final_pass is true. 352int VP8EmitTokens(VP8TBuffer* const b, VP8BitWriter* const bw, 353 const uint8_t* const probas, int final_pass); 354 355// record the coding of coefficients without knowing the probabilities yet 356int VP8RecordCoeffTokens(int ctx, int coeff_type, int first, int last, 357 const int16_t* const coeffs, 358 VP8TBuffer* const tokens); 359 360// unused for now 361void VP8TokenToStats(const VP8TBuffer* const b, proba_t* const stats); 362 363#endif // !DISABLE_TOKEN_BUFFER 364 365//------------------------------------------------------------------------------ 366// VP8Encoder 367 368struct VP8Encoder { 369 const WebPConfig* config_; // user configuration and parameters 370 WebPPicture* pic_; // input / output picture 371 372 // headers 373 VP8FilterHeader filter_hdr_; // filtering information 374 VP8SegmentHeader segment_hdr_; // segment information 375 376 int profile_; // VP8's profile, deduced from Config. 377 378 // dimension, in macroblock units. 379 int mb_w_, mb_h_; 380 int preds_w_; // stride of the *preds_ prediction plane (=4*mb_w + 1) 381 382 // number of partitions (1, 2, 4 or 8 = MAX_NUM_PARTITIONS) 383 int num_parts_; 384 385 // per-partition boolean decoders. 386 VP8BitWriter bw_; // part0 387 VP8BitWriter parts_[MAX_NUM_PARTITIONS]; // token partitions 388 VP8TBuffer tokens_; // token buffer 389 390 int percent_; // for progress 391 392 // transparency blob 393 int has_alpha_; 394 uint8_t* alpha_data_; // non-NULL if transparency is present 395 uint32_t alpha_data_size_; 396 WebPWorker alpha_worker_; 397 398 // enhancement layer 399 int use_layer_; 400 VP8BitWriter layer_bw_; 401 uint8_t* layer_data_; 402 size_t layer_data_size_; 403 404 // quantization info (one set of DC/AC dequant factor per segment) 405 VP8SegmentInfo dqm_[NUM_MB_SEGMENTS]; 406 int base_quant_; // nominal quantizer value. Only used 407 // for relative coding of segments' quant. 408 int alpha_; // global susceptibility (<=> complexity) 409 int uv_alpha_; // U/V quantization susceptibility 410 // global offset of quantizers, shared by all segments 411 int dq_y1_dc_; 412 int dq_y2_dc_, dq_y2_ac_; 413 int dq_uv_dc_, dq_uv_ac_; 414 415 // probabilities and statistics 416 VP8Proba proba_; 417 uint64_t sse_[4]; // sum of Y/U/V/A squared errors for all macroblocks 418 uint64_t sse_count_; // pixel count for the sse_[] stats 419 int coded_size_; 420 int residual_bytes_[3][4]; 421 int block_count_[3]; 422 423 // quality/speed settings 424 int method_; // 0=fastest, 6=best/slowest. 425 VP8RDLevel rd_opt_level_; // Deduced from method_. 426 int max_i4_header_bits_; // partition #0 safeness factor 427 int thread_level_; // derived from config->thread_level 428 int do_search_; // derived from config->target_XXX 429 int use_tokens_; // if true, use token buffer 430 431 // Memory 432 VP8MBInfo* mb_info_; // contextual macroblock infos (mb_w_ + 1) 433 uint8_t* preds_; // predictions modes: (4*mb_w+1) * (4*mb_h+1) 434 uint32_t* nz_; // non-zero bit context: mb_w+1 435 uint8_t* yuv_in_; // input samples 436 uint8_t* yuv_out_; // output samples 437 uint8_t* yuv_out2_; // secondary scratch out-buffer. swapped with yuv_out_. 438 uint8_t* yuv_p_; // scratch buffer for prediction 439 uint8_t *y_top_; // top luma samples. 440 uint8_t *uv_top_; // top u/v samples. 441 // U and V are packed into 16 pixels (8 U + 8 V) 442 uint8_t *y_left_; // left luma samples (adressable from index -1 to 15). 443 uint8_t *u_left_; // left u samples (adressable from index -1 to 7) 444 uint8_t *v_left_; // left v samples (adressable from index -1 to 7) 445 446 LFStats *lf_stats_; // autofilter stats (if NULL, autofilter is off) 447}; 448 449//------------------------------------------------------------------------------ 450// internal functions. Not public. 451 452 // in tree.c 453extern const uint8_t VP8CoeffsProba0[NUM_TYPES][NUM_BANDS][NUM_CTX][NUM_PROBAS]; 454extern const uint8_t 455 VP8CoeffsUpdateProba[NUM_TYPES][NUM_BANDS][NUM_CTX][NUM_PROBAS]; 456// Reset the token probabilities to their initial (default) values 457void VP8DefaultProbas(VP8Encoder* const enc); 458// Write the token probabilities 459void VP8WriteProbas(VP8BitWriter* const bw, const VP8Proba* const probas); 460// Writes the partition #0 modes (that is: all intra modes) 461void VP8CodeIntraModes(VP8Encoder* const enc); 462 463 // in syntax.c 464// Generates the final bitstream by coding the partition0 and headers, 465// and appending an assembly of all the pre-coded token partitions. 466// Return true if everything is ok. 467int VP8EncWrite(VP8Encoder* const enc); 468// Release memory allocated for bit-writing in VP8EncLoop & seq. 469void VP8EncFreeBitWriters(VP8Encoder* const enc); 470 471 // in frame.c 472extern const uint8_t VP8EncBands[16 + 1]; 473extern const uint8_t VP8Cat3[]; 474extern const uint8_t VP8Cat4[]; 475extern const uint8_t VP8Cat5[]; 476extern const uint8_t VP8Cat6[]; 477 478// Form all the four Intra16x16 predictions in the yuv_p_ cache 479void VP8MakeLuma16Preds(const VP8EncIterator* const it); 480// Form all the four Chroma8x8 predictions in the yuv_p_ cache 481void VP8MakeChroma8Preds(const VP8EncIterator* const it); 482// Form all the ten Intra4x4 predictions in the yuv_p_ cache 483// for the 4x4 block it->i4_ 484void VP8MakeIntra4Preds(const VP8EncIterator* const it); 485// Rate calculation 486int VP8GetCostLuma16(VP8EncIterator* const it, const VP8ModeScore* const rd); 487int VP8GetCostLuma4(VP8EncIterator* const it, const int16_t levels[16]); 488int VP8GetCostUV(VP8EncIterator* const it, const VP8ModeScore* const rd); 489// Main coding calls 490int VP8EncLoop(VP8Encoder* const enc); 491int VP8EncTokenLoop(VP8Encoder* const enc); 492 493 // in webpenc.c 494// Assign an error code to a picture. Return false for convenience. 495int WebPEncodingSetError(const WebPPicture* const pic, WebPEncodingError error); 496int WebPReportProgress(const WebPPicture* const pic, 497 int percent, int* const percent_store); 498 499 // in analysis.c 500// Main analysis loop. Decides the segmentations and complexity. 501// Assigns a first guess for Intra16 and uvmode_ prediction modes. 502int VP8EncAnalyze(VP8Encoder* const enc); 503 504 // in quant.c 505// Sets up segment's quantization values, base_quant_ and filter strengths. 506void VP8SetSegmentParams(VP8Encoder* const enc, float quality); 507// Pick best modes and fills the levels. Returns true if skipped. 508int VP8Decimate(VP8EncIterator* const it, VP8ModeScore* const rd, 509 VP8RDLevel rd_opt); 510 511 // in alpha.c 512void VP8EncInitAlpha(VP8Encoder* const enc); // initialize alpha compression 513int VP8EncStartAlpha(VP8Encoder* const enc); // start alpha coding process 514int VP8EncFinishAlpha(VP8Encoder* const enc); // finalize compressed data 515int VP8EncDeleteAlpha(VP8Encoder* const enc); // delete compressed data 516 517 // in layer.c 518void VP8EncInitLayer(VP8Encoder* const enc); // init everything 519void VP8EncCodeLayerBlock(VP8EncIterator* it); // code one more macroblock 520int VP8EncFinishLayer(VP8Encoder* const enc); // finalize coding 521void VP8EncDeleteLayer(VP8Encoder* enc); // reclaim memory 522 523 // in filter.c 524 525// SSIM utils 526typedef struct { 527 double w, xm, ym, xxm, xym, yym; 528} DistoStats; 529void VP8SSIMAddStats(const DistoStats* const src, DistoStats* const dst); 530void VP8SSIMAccumulatePlane(const uint8_t* src1, int stride1, 531 const uint8_t* src2, int stride2, 532 int W, int H, DistoStats* const stats); 533double VP8SSIMGet(const DistoStats* const stats); 534double VP8SSIMGetSquaredError(const DistoStats* const stats); 535 536// autofilter 537void VP8InitFilter(VP8EncIterator* const it); 538void VP8StoreFilterStats(VP8EncIterator* const it); 539void VP8AdjustFilterStrength(VP8EncIterator* const it); 540 541//------------------------------------------------------------------------------ 542 543#if defined(__cplusplus) || defined(c_plusplus) 544} // extern "C" 545#endif 546 547#endif /* WEBP_ENC_VP8ENCI_H_ */ 548