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 // WebP encoder: internal header. 11 // 12 // Author: Skal (pascal.massimino (at) gmail.com) 13 14 #ifndef WEBP_ENC_VP8ENCI_H_ 15 #define WEBP_ENC_VP8ENCI_H_ 16 17 #include <string.h> // for memcpy() 18 #include "../dec/common.h" 19 #include "../dsp/dsp.h" 20 #include "../utils/bit_writer.h" 21 #include "../utils/thread.h" 22 #include "../utils/utils.h" 23 #include "../webp/encode.h" 24 25 #ifdef WEBP_EXPERIMENTAL_FEATURES 26 #include "./vp8li.h" 27 #endif // WEBP_EXPERIMENTAL_FEATURES 28 29 #ifdef __cplusplus 30 extern "C" { 31 #endif 32 33 //------------------------------------------------------------------------------ 34 // Various defines and enums 35 36 // version numbers 37 #define ENC_MAJ_VERSION 0 38 #define ENC_MIN_VERSION 5 39 #define ENC_REV_VERSION 0 40 41 enum { MAX_LF_LEVELS = 64, // Maximum loop filter level 42 MAX_VARIABLE_LEVEL = 67, // last (inclusive) level with variable cost 43 MAX_LEVEL = 2047 // max level (note: max codable is 2047 + 67) 44 }; 45 46 typedef enum { // Rate-distortion optimization levels 47 RD_OPT_NONE = 0, // no rd-opt 48 RD_OPT_BASIC = 1, // basic scoring (no trellis) 49 RD_OPT_TRELLIS = 2, // perform trellis-quant on the final decision only 50 RD_OPT_TRELLIS_ALL = 3 // trellis-quant for every scoring (much slower) 51 } VP8RDLevel; 52 53 // YUV-cache parameters. Cache is 32-bytes wide (= one cacheline). 54 // The original or reconstructed samples can be accessed using VP8Scan[]. 55 // The predicted blocks can be accessed using offsets to yuv_p_ and 56 // the arrays VP8*ModeOffsets[]. 57 // * YUV Samples area (yuv_in_/yuv_out_/yuv_out2_) 58 // (see VP8Scan[] for accessing the blocks, along with 59 // Y_OFF_ENC/U_OFF_ENC/V_OFF_ENC): 60 // +----+----+ 61 // Y_OFF_ENC |YYYY|UUVV| 62 // U_OFF_ENC |YYYY|UUVV| 63 // V_OFF_ENC |YYYY|....| <- 25% wasted U/V area 64 // |YYYY|....| 65 // +----+----+ 66 // * Prediction area ('yuv_p_', size = PRED_SIZE_ENC) 67 // Intra16 predictions (16x16 block each, two per row): 68 // |I16DC16|I16TM16| 69 // |I16VE16|I16HE16| 70 // Chroma U/V predictions (16x8 block each, two per row): 71 // |C8DC8|C8TM8| 72 // |C8VE8|C8HE8| 73 // Intra 4x4 predictions (4x4 block each) 74 // |I4DC4 I4TM4 I4VE4 I4HE4|I4RD4 I4VR4 I4LD4 I4VL4| 75 // |I4HD4 I4HU4 I4TMP .....|.......................| <- ~31% wasted 76 #define YUV_SIZE_ENC (BPS * 16) 77 #define PRED_SIZE_ENC (32 * BPS + 16 * BPS + 8 * BPS) // I16+Chroma+I4 preds 78 #define Y_OFF_ENC (0) 79 #define U_OFF_ENC (16) 80 #define V_OFF_ENC (16 + 8) 81 82 extern const int VP8Scan[16]; // in quant.c 83 extern const int VP8UVModeOffsets[4]; // in analyze.c 84 extern const int VP8I16ModeOffsets[4]; 85 extern const int VP8I4ModeOffsets[NUM_BMODES]; 86 87 // Layout of prediction blocks 88 // intra 16x16 89 #define I16DC16 (0 * 16 * BPS) 90 #define I16TM16 (I16DC16 + 16) 91 #define I16VE16 (1 * 16 * BPS) 92 #define I16HE16 (I16VE16 + 16) 93 // chroma 8x8, two U/V blocks side by side (hence: 16x8 each) 94 #define C8DC8 (2 * 16 * BPS) 95 #define C8TM8 (C8DC8 + 1 * 16) 96 #define C8VE8 (2 * 16 * BPS + 8 * BPS) 97 #define C8HE8 (C8VE8 + 1 * 16) 98 // intra 4x4 99 #define I4DC4 (3 * 16 * BPS + 0) 100 #define I4TM4 (I4DC4 + 4) 101 #define I4VE4 (I4DC4 + 8) 102 #define I4HE4 (I4DC4 + 12) 103 #define I4RD4 (I4DC4 + 16) 104 #define I4VR4 (I4DC4 + 20) 105 #define I4LD4 (I4DC4 + 24) 106 #define I4VL4 (I4DC4 + 28) 107 #define I4HD4 (3 * 16 * BPS + 4 * BPS) 108 #define I4HU4 (I4HD4 + 4) 109 #define I4TMP (I4HD4 + 8) 110 111 typedef int64_t score_t; // type used for scores, rate, distortion 112 // Note that MAX_COST is not the maximum allowed by sizeof(score_t), 113 // in order to allow overflowing computations. 114 #define MAX_COST ((score_t)0x7fffffffffffffLL) 115 116 #define QFIX 17 117 #define BIAS(b) ((b) << (QFIX - 8)) 118 // Fun fact: this is the _only_ line where we're actually being lossy and 119 // discarding bits. 120 static WEBP_INLINE int QUANTDIV(uint32_t n, uint32_t iQ, uint32_t B) { 121 return (int)((n * iQ + B) >> QFIX); 122 } 123 124 // Uncomment the following to remove token-buffer code: 125 // #define DISABLE_TOKEN_BUFFER 126 127 //------------------------------------------------------------------------------ 128 // Headers 129 130 typedef uint32_t proba_t; // 16b + 16b 131 typedef uint8_t ProbaArray[NUM_CTX][NUM_PROBAS]; 132 typedef proba_t StatsArray[NUM_CTX][NUM_PROBAS]; 133 typedef uint16_t CostArray[NUM_CTX][MAX_VARIABLE_LEVEL + 1]; 134 typedef const uint16_t* (*CostArrayPtr)[NUM_CTX]; // for easy casting 135 typedef const uint16_t* CostArrayMap[16][NUM_CTX]; 136 typedef double LFStats[NUM_MB_SEGMENTS][MAX_LF_LEVELS]; // filter stats 137 138 typedef struct VP8Encoder VP8Encoder; 139 140 // segment features 141 typedef struct { 142 int num_segments_; // Actual number of segments. 1 segment only = unused. 143 int update_map_; // whether to update the segment map or not. 144 // must be 0 if there's only 1 segment. 145 int size_; // bit-cost for transmitting the segment map 146 } VP8EncSegmentHeader; 147 148 // Struct collecting all frame-persistent probabilities. 149 typedef struct { 150 uint8_t segments_[3]; // probabilities for segment tree 151 uint8_t skip_proba_; // final probability of being skipped. 152 ProbaArray coeffs_[NUM_TYPES][NUM_BANDS]; // 1056 bytes 153 StatsArray stats_[NUM_TYPES][NUM_BANDS]; // 4224 bytes 154 CostArray level_cost_[NUM_TYPES][NUM_BANDS]; // 13056 bytes 155 CostArrayMap remapped_costs_[NUM_TYPES]; // 1536 bytes 156 int dirty_; // if true, need to call VP8CalculateLevelCosts() 157 int use_skip_proba_; // Note: we always use skip_proba for now. 158 int nb_skip_; // number of skipped blocks 159 } VP8EncProba; 160 161 // Filter parameters. Not actually used in the code (we don't perform 162 // the in-loop filtering), but filled from user's config 163 typedef struct { 164 int simple_; // filtering type: 0=complex, 1=simple 165 int level_; // base filter level [0..63] 166 int sharpness_; // [0..7] 167 int i4x4_lf_delta_; // delta filter level for i4x4 relative to i16x16 168 } VP8EncFilterHeader; 169 170 //------------------------------------------------------------------------------ 171 // Informations about the macroblocks. 172 173 typedef struct { 174 // block type 175 unsigned int type_:2; // 0=i4x4, 1=i16x16 176 unsigned int uv_mode_:2; 177 unsigned int skip_:1; 178 unsigned int segment_:2; 179 uint8_t alpha_; // quantization-susceptibility 180 } VP8MBInfo; 181 182 typedef struct VP8Matrix { 183 uint16_t q_[16]; // quantizer steps 184 uint16_t iq_[16]; // reciprocals, fixed point. 185 uint32_t bias_[16]; // rounding bias 186 uint32_t zthresh_[16]; // value below which a coefficient is zeroed 187 uint16_t sharpen_[16]; // frequency boosters for slight sharpening 188 } VP8Matrix; 189 190 typedef struct { 191 VP8Matrix y1_, y2_, uv_; // quantization matrices 192 int alpha_; // quant-susceptibility, range [-127,127]. Zero is neutral. 193 // Lower values indicate a lower risk of blurriness. 194 int beta_; // filter-susceptibility, range [0,255]. 195 int quant_; // final segment quantizer. 196 int fstrength_; // final in-loop filtering strength 197 int max_edge_; // max edge delta (for filtering strength) 198 int min_disto_; // minimum distortion required to trigger filtering record 199 // reactivities 200 int lambda_i16_, lambda_i4_, lambda_uv_; 201 int lambda_mode_, lambda_trellis_, tlambda_; 202 int lambda_trellis_i16_, lambda_trellis_i4_, lambda_trellis_uv_; 203 } VP8SegmentInfo; 204 205 // Handy transient struct to accumulate score and info during RD-optimization 206 // and mode evaluation. 207 typedef struct { 208 score_t D, SD; // Distortion, spectral distortion 209 score_t H, R, score; // header bits, rate, score. 210 int16_t y_dc_levels[16]; // Quantized levels for luma-DC, luma-AC, chroma. 211 int16_t y_ac_levels[16][16]; 212 int16_t uv_levels[4 + 4][16]; 213 int mode_i16; // mode number for intra16 prediction 214 uint8_t modes_i4[16]; // mode numbers for intra4 predictions 215 int mode_uv; // mode number of chroma prediction 216 uint32_t nz; // non-zero blocks 217 } VP8ModeScore; 218 219 // Iterator structure to iterate through macroblocks, pointing to the 220 // right neighbouring data (samples, predictions, contexts, ...) 221 typedef struct { 222 int x_, y_; // current macroblock 223 int y_stride_, uv_stride_; // respective strides 224 uint8_t* yuv_in_; // input samples 225 uint8_t* yuv_out_; // output samples 226 uint8_t* yuv_out2_; // secondary buffer swapped with yuv_out_. 227 uint8_t* yuv_p_; // scratch buffer for prediction 228 VP8Encoder* enc_; // back-pointer 229 VP8MBInfo* mb_; // current macroblock 230 VP8BitWriter* bw_; // current bit-writer 231 uint8_t* preds_; // intra mode predictors (4x4 blocks) 232 uint32_t* nz_; // non-zero pattern 233 uint8_t i4_boundary_[37]; // 32+5 boundary samples needed by intra4x4 234 uint8_t* i4_top_; // pointer to the current top boundary sample 235 int i4_; // current intra4x4 mode being tested 236 int top_nz_[9]; // top-non-zero context. 237 int left_nz_[9]; // left-non-zero. left_nz[8] is independent. 238 uint64_t bit_count_[4][3]; // bit counters for coded levels. 239 uint64_t luma_bits_; // macroblock bit-cost for luma 240 uint64_t uv_bits_; // macroblock bit-cost for chroma 241 LFStats* lf_stats_; // filter stats (borrowed from enc_) 242 int do_trellis_; // if true, perform extra level optimisation 243 int count_down_; // number of mb still to be processed 244 int count_down0_; // starting counter value (for progress) 245 int percent0_; // saved initial progress percent 246 247 uint8_t* y_left_; // left luma samples (addressable from index -1 to 15). 248 uint8_t* u_left_; // left u samples (addressable from index -1 to 7) 249 uint8_t* v_left_; // left v samples (addressable from index -1 to 7) 250 251 uint8_t* y_top_; // top luma samples at position 'x_' 252 uint8_t* uv_top_; // top u/v samples at position 'x_', packed as 16 bytes 253 254 // memory for storing y/u/v_left_ 255 uint8_t yuv_left_mem_[17 + 16 + 16 + 8 + WEBP_ALIGN_CST]; 256 // memory for yuv_* 257 uint8_t yuv_mem_[3 * YUV_SIZE_ENC + PRED_SIZE_ENC + WEBP_ALIGN_CST]; 258 } VP8EncIterator; 259 260 // in iterator.c 261 // must be called first 262 void VP8IteratorInit(VP8Encoder* const enc, VP8EncIterator* const it); 263 // restart a scan 264 void VP8IteratorReset(VP8EncIterator* const it); 265 // reset iterator position to row 'y' 266 void VP8IteratorSetRow(VP8EncIterator* const it, int y); 267 // set count down (=number of iterations to go) 268 void VP8IteratorSetCountDown(VP8EncIterator* const it, int count_down); 269 // return true if iteration is finished 270 int VP8IteratorIsDone(const VP8EncIterator* const it); 271 // Import uncompressed samples from source. 272 // If tmp_32 is not NULL, import boundary samples too. 273 // tmp_32 is a 32-bytes scratch buffer that must be aligned in memory. 274 void VP8IteratorImport(VP8EncIterator* const it, uint8_t* tmp_32); 275 // export decimated samples 276 void VP8IteratorExport(const VP8EncIterator* const it); 277 // go to next macroblock. Returns false if not finished. 278 int VP8IteratorNext(VP8EncIterator* const it); 279 // save the yuv_out_ boundary values to top_/left_ arrays for next iterations. 280 void VP8IteratorSaveBoundary(VP8EncIterator* const it); 281 // Report progression based on macroblock rows. Return 0 for user-abort request. 282 int VP8IteratorProgress(const VP8EncIterator* const it, 283 int final_delta_percent); 284 // Intra4x4 iterations 285 void VP8IteratorStartI4(VP8EncIterator* const it); 286 // returns true if not done. 287 int VP8IteratorRotateI4(VP8EncIterator* const it, 288 const uint8_t* const yuv_out); 289 290 // Non-zero context setup/teardown 291 void VP8IteratorNzToBytes(VP8EncIterator* const it); 292 void VP8IteratorBytesToNz(VP8EncIterator* const it); 293 294 // Helper functions to set mode properties 295 void VP8SetIntra16Mode(const VP8EncIterator* const it, int mode); 296 void VP8SetIntra4Mode(const VP8EncIterator* const it, const uint8_t* modes); 297 void VP8SetIntraUVMode(const VP8EncIterator* const it, int mode); 298 void VP8SetSkip(const VP8EncIterator* const it, int skip); 299 void VP8SetSegment(const VP8EncIterator* const it, int segment); 300 301 //------------------------------------------------------------------------------ 302 // Paginated token buffer 303 304 typedef struct VP8Tokens VP8Tokens; // struct details in token.c 305 306 typedef struct { 307 #if !defined(DISABLE_TOKEN_BUFFER) 308 VP8Tokens* pages_; // first page 309 VP8Tokens** last_page_; // last page 310 uint16_t* tokens_; // set to (*last_page_)->tokens_ 311 int left_; // how many free tokens left before the page is full 312 int page_size_; // number of tokens per page 313 #endif 314 int error_; // true in case of malloc error 315 } VP8TBuffer; 316 317 // initialize an empty buffer 318 void VP8TBufferInit(VP8TBuffer* const b, int page_size); 319 void VP8TBufferClear(VP8TBuffer* const b); // de-allocate pages memory 320 321 #if !defined(DISABLE_TOKEN_BUFFER) 322 323 // Finalizes bitstream when probabilities are known. 324 // Deletes the allocated token memory if final_pass is true. 325 int VP8EmitTokens(VP8TBuffer* const b, VP8BitWriter* const bw, 326 const uint8_t* const probas, int final_pass); 327 328 // record the coding of coefficients without knowing the probabilities yet 329 int VP8RecordCoeffTokens(const int ctx, const int coeff_type, 330 int first, int last, 331 const int16_t* const coeffs, 332 VP8TBuffer* const tokens); 333 334 // Estimate the final coded size given a set of 'probas'. 335 size_t VP8EstimateTokenSize(VP8TBuffer* const b, const uint8_t* const probas); 336 337 // unused for now 338 void VP8TokenToStats(const VP8TBuffer* const b, proba_t* const stats); 339 340 #endif // !DISABLE_TOKEN_BUFFER 341 342 //------------------------------------------------------------------------------ 343 // VP8Encoder 344 345 struct VP8Encoder { 346 const WebPConfig* config_; // user configuration and parameters 347 WebPPicture* pic_; // input / output picture 348 349 // headers 350 VP8EncFilterHeader filter_hdr_; // filtering information 351 VP8EncSegmentHeader segment_hdr_; // segment information 352 353 int profile_; // VP8's profile, deduced from Config. 354 355 // dimension, in macroblock units. 356 int mb_w_, mb_h_; 357 int preds_w_; // stride of the *preds_ prediction plane (=4*mb_w + 1) 358 359 // number of partitions (1, 2, 4 or 8 = MAX_NUM_PARTITIONS) 360 int num_parts_; 361 362 // per-partition boolean decoders. 363 VP8BitWriter bw_; // part0 364 VP8BitWriter parts_[MAX_NUM_PARTITIONS]; // token partitions 365 VP8TBuffer tokens_; // token buffer 366 367 int percent_; // for progress 368 369 // transparency blob 370 int has_alpha_; 371 uint8_t* alpha_data_; // non-NULL if transparency is present 372 uint32_t alpha_data_size_; 373 WebPWorker alpha_worker_; 374 375 // quantization info (one set of DC/AC dequant factor per segment) 376 VP8SegmentInfo dqm_[NUM_MB_SEGMENTS]; 377 int base_quant_; // nominal quantizer value. Only used 378 // for relative coding of segments' quant. 379 int alpha_; // global susceptibility (<=> complexity) 380 int uv_alpha_; // U/V quantization susceptibility 381 // global offset of quantizers, shared by all segments 382 int dq_y1_dc_; 383 int dq_y2_dc_, dq_y2_ac_; 384 int dq_uv_dc_, dq_uv_ac_; 385 386 // probabilities and statistics 387 VP8EncProba proba_; 388 uint64_t sse_[4]; // sum of Y/U/V/A squared errors for all macroblocks 389 uint64_t sse_count_; // pixel count for the sse_[] stats 390 int coded_size_; 391 int residual_bytes_[3][4]; 392 int block_count_[3]; 393 394 // quality/speed settings 395 int method_; // 0=fastest, 6=best/slowest. 396 VP8RDLevel rd_opt_level_; // Deduced from method_. 397 int max_i4_header_bits_; // partition #0 safeness factor 398 int thread_level_; // derived from config->thread_level 399 int do_search_; // derived from config->target_XXX 400 int use_tokens_; // if true, use token buffer 401 402 // Memory 403 VP8MBInfo* mb_info_; // contextual macroblock infos (mb_w_ + 1) 404 uint8_t* preds_; // predictions modes: (4*mb_w+1) * (4*mb_h+1) 405 uint32_t* nz_; // non-zero bit context: mb_w+1 406 uint8_t* y_top_; // top luma samples. 407 uint8_t* uv_top_; // top u/v samples. 408 // U and V are packed into 16 bytes (8 U + 8 V) 409 LFStats* lf_stats_; // autofilter stats (if NULL, autofilter is off) 410 }; 411 412 //------------------------------------------------------------------------------ 413 // internal functions. Not public. 414 415 // in tree.c 416 extern const uint8_t VP8CoeffsProba0[NUM_TYPES][NUM_BANDS][NUM_CTX][NUM_PROBAS]; 417 extern const uint8_t 418 VP8CoeffsUpdateProba[NUM_TYPES][NUM_BANDS][NUM_CTX][NUM_PROBAS]; 419 // Reset the token probabilities to their initial (default) values 420 void VP8DefaultProbas(VP8Encoder* const enc); 421 // Write the token probabilities 422 void VP8WriteProbas(VP8BitWriter* const bw, const VP8EncProba* const probas); 423 // Writes the partition #0 modes (that is: all intra modes) 424 void VP8CodeIntraModes(VP8Encoder* const enc); 425 426 // in syntax.c 427 // Generates the final bitstream by coding the partition0 and headers, 428 // and appending an assembly of all the pre-coded token partitions. 429 // Return true if everything is ok. 430 int VP8EncWrite(VP8Encoder* const enc); 431 // Release memory allocated for bit-writing in VP8EncLoop & seq. 432 void VP8EncFreeBitWriters(VP8Encoder* const enc); 433 434 // in frame.c 435 extern const uint8_t VP8Cat3[]; 436 extern const uint8_t VP8Cat4[]; 437 extern const uint8_t VP8Cat5[]; 438 extern const uint8_t VP8Cat6[]; 439 440 // Form all the four Intra16x16 predictions in the yuv_p_ cache 441 void VP8MakeLuma16Preds(const VP8EncIterator* const it); 442 // Form all the four Chroma8x8 predictions in the yuv_p_ cache 443 void VP8MakeChroma8Preds(const VP8EncIterator* const it); 444 // Form all the ten Intra4x4 predictions in the yuv_p_ cache 445 // for the 4x4 block it->i4_ 446 void VP8MakeIntra4Preds(const VP8EncIterator* const it); 447 // Rate calculation 448 int VP8GetCostLuma16(VP8EncIterator* const it, const VP8ModeScore* const rd); 449 int VP8GetCostLuma4(VP8EncIterator* const it, const int16_t levels[16]); 450 int VP8GetCostUV(VP8EncIterator* const it, const VP8ModeScore* const rd); 451 // Main coding calls 452 int VP8EncLoop(VP8Encoder* const enc); 453 int VP8EncTokenLoop(VP8Encoder* const enc); 454 455 // in webpenc.c 456 // Assign an error code to a picture. Return false for convenience. 457 int WebPEncodingSetError(const WebPPicture* const pic, WebPEncodingError error); 458 int WebPReportProgress(const WebPPicture* const pic, 459 int percent, int* const percent_store); 460 461 // in analysis.c 462 // Main analysis loop. Decides the segmentations and complexity. 463 // Assigns a first guess for Intra16 and uvmode_ prediction modes. 464 int VP8EncAnalyze(VP8Encoder* const enc); 465 466 // in quant.c 467 // Sets up segment's quantization values, base_quant_ and filter strengths. 468 void VP8SetSegmentParams(VP8Encoder* const enc, float quality); 469 // Pick best modes and fills the levels. Returns true if skipped. 470 int VP8Decimate(VP8EncIterator* const it, VP8ModeScore* const rd, 471 VP8RDLevel rd_opt); 472 473 // in alpha.c 474 void VP8EncInitAlpha(VP8Encoder* const enc); // initialize alpha compression 475 int VP8EncStartAlpha(VP8Encoder* const enc); // start alpha coding process 476 int VP8EncFinishAlpha(VP8Encoder* const enc); // finalize compressed data 477 int VP8EncDeleteAlpha(VP8Encoder* const enc); // delete compressed data 478 479 // in filter.c 480 481 // SSIM utils 482 typedef struct { 483 double w, xm, ym, xxm, xym, yym; 484 } DistoStats; 485 void VP8SSIMAddStats(const DistoStats* const src, DistoStats* const dst); 486 void VP8SSIMAccumulatePlane(const uint8_t* src1, int stride1, 487 const uint8_t* src2, int stride2, 488 int W, int H, DistoStats* const stats); 489 double VP8SSIMGet(const DistoStats* const stats); 490 double VP8SSIMGetSquaredError(const DistoStats* const stats); 491 492 // autofilter 493 void VP8InitFilter(VP8EncIterator* const it); 494 void VP8StoreFilterStats(VP8EncIterator* const it); 495 void VP8AdjustFilterStrength(VP8EncIterator* const it); 496 497 // returns the approximate filtering strength needed to smooth a edge 498 // step of 'delta', given a sharpness parameter 'sharpness'. 499 int VP8FilterStrengthFromDelta(int sharpness, int delta); 500 501 // misc utils for picture_*.c: 502 503 // Remove reference to the ARGB/YUVA buffer (doesn't free anything). 504 void WebPPictureResetBuffers(WebPPicture* const picture); 505 506 // Allocates ARGB buffer of given dimension (previous one is always free'd). 507 // Preserves the YUV(A) buffer. Returns false in case of error (invalid param, 508 // out-of-memory). 509 int WebPPictureAllocARGB(WebPPicture* const picture, int width, int height); 510 511 // Allocates YUVA buffer of given dimension (previous one is always free'd). 512 // Uses picture->csp to determine whether an alpha buffer is needed. 513 // Preserves the ARGB buffer. 514 // Returns false in case of error (invalid param, out-of-memory). 515 int WebPPictureAllocYUVA(WebPPicture* const picture, int width, int height); 516 517 // Clean-up the RGB samples under fully transparent area, to help lossless 518 // compressibility (no guarantee, though). Assumes that pic->use_argb is true. 519 void WebPCleanupTransparentAreaLossless(WebPPicture* const pic); 520 521 // in near_lossless.c 522 // Near lossless preprocessing in RGB color-space. 523 int VP8ApplyNearLossless(int xsize, int ysize, uint32_t* argb, int quality); 524 // Near lossless adjustment for predictors. 525 void VP8ApplyNearLosslessPredict(int xsize, int ysize, int pred_bits, 526 const uint32_t* argb_orig, 527 uint32_t* argb, uint32_t* argb_scratch, 528 const uint32_t* const transform_data, 529 int quality, int subtract_green); 530 //------------------------------------------------------------------------------ 531 532 #ifdef __cplusplus 533 } // extern "C" 534 #endif 535 536 #endif /* WEBP_ENC_VP8ENCI_H_ */ 537
