third_party/libwebp/enc/vp8enci.h

   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@gmail.com)
  13
  14 #ifndef WEBP_ENC_VP8ENCI_H_
  15 #define WEBP_ENC_VP8ENCI_H_
  16
  17 #include <string.h>     // for memcpy()
  18 #include "../webp/encode.h"
  19 #include "../dsp/dsp.h"
  20 #include "../utils/bit_writer.h"
  21 #include "../utils/thread.h"
  22
  23 #ifdef __cplusplus
  24 extern "C" {
  25 #endif
  26
  27 //------------------------------------------------------------------------------
  28 // Various defines and enums
  29
  30 // version numbers
  31 #define ENC_MAJ_VERSION 0
  32 #define ENC_MIN_VERSION 4
  33 #define ENC_REV_VERSION 0
  34
  35 // intra prediction modes
  36 enum { B_DC_PRED = 0,   // 4x4 modes
  37        B_TM_PRED = 1,
  38        B_VE_PRED = 2,
  39        B_HE_PRED = 3,
  40        B_RD_PRED = 4,
  41        B_VR_PRED = 5,
  42        B_LD_PRED = 6,
  43        B_VL_PRED = 7,
  44        B_HD_PRED = 8,
  45        B_HU_PRED = 9,
  46        NUM_BMODES = B_HU_PRED + 1 - B_DC_PRED,  // = 10
  47
  48        // Luma16 or UV modes
  49        DC_PRED = B_DC_PRED, V_PRED = B_VE_PRED,
  50        H_PRED = B_HE_PRED, TM_PRED = B_TM_PRED,
  51        NUM_PRED_MODES = 4
  52      };
  53
  54 enum { NUM_MB_SEGMENTS = 4,
  55        MAX_NUM_PARTITIONS = 8,
  56        NUM_TYPES = 4,   // 0: i16-AC,  1: i16-DC,  2:chroma-AC,  3:i4-AC
  57        NUM_BANDS = 8,
  58        NUM_CTX = 3,
  59        NUM_PROBAS = 11,
  60        MAX_LF_LEVELS = 64,       // Maximum loop filter level
  61        MAX_VARIABLE_LEVEL = 67,  // last (inclusive) level with variable cost
  62        MAX_LEVEL = 2047          // max level (note: max codable is 2047 + 67)
  63      };
  64
  65 typedef enum {   // Rate-distortion optimization levels
  66   RD_OPT_NONE        = 0,  // no rd-opt
  67   RD_OPT_BASIC       = 1,  // basic scoring (no trellis)
  68   RD_OPT_TRELLIS     = 2,  // perform trellis-quant on the final decision only
  69   RD_OPT_TRELLIS_ALL = 3   // trellis-quant for every scoring (much slower)
  70 } VP8RDLevel;
  71
  72 // YUV-cache parameters. Cache is 16-pixels wide.
  73 // The original or reconstructed samples can be accessed using VP8Scan[]
  74 // The predicted blocks can be accessed using offsets to yuv_p_ and
  75 // the arrays VP8*ModeOffsets[];
  76 //         +----+      YUV Samples area. See VP8Scan[] for accessing the blocks.
  77 //  Y_OFF  |YYYY| <- original samples  ('yuv_in_')
  78 //         |YYYY|
  79 //         |YYYY|
  80 //         |YYYY|
  81 //  U_OFF  |UUVV| V_OFF  (=U_OFF + 8)
  82 //         |UUVV|
  83 //         +----+
  84 //  Y_OFF  |YYYY| <- compressed/decoded samples  ('yuv_out_')
  85 //         |YYYY|    There are two buffers like this ('yuv_out_'/'yuv_out2_')
  86 //         |YYYY|
  87 //         |YYYY|
  88 //  U_OFF  |UUVV| V_OFF
  89 //         |UUVV|
  90 //          x2 (for yuv_out2_)
  91 //         +----+     Prediction area ('yuv_p_', size = PRED_SIZE)
  92 // I16DC16 |YYYY|  Intra16 predictions (16x16 block each)
  93 //         |YYYY|
  94 //         |YYYY|
  95 //         |YYYY|
  96 // I16TM16 |YYYY|
  97 //         |YYYY|
  98 //         |YYYY|
  99 //         |YYYY|
 100 // I16VE16 |YYYY|
 101 //         |YYYY|
 102 //         |YYYY|
 103 //         |YYYY|
 104 // I16HE16 |YYYY|
 105 //         |YYYY|
 106 //         |YYYY|
 107 //         |YYYY|
 108 //         +----+  Chroma U/V predictions (16x8 block each)
 109 // C8DC8   |UUVV|
 110 //         |UUVV|
 111 // C8TM8   |UUVV|
 112 //         |UUVV|
 113 // C8VE8   |UUVV|
 114 //         |UUVV|
 115 // C8HE8   |UUVV|
 116 //         |UUVV|
 117 //         +----+  Intra 4x4 predictions (4x4 block each)
 118 //         |YYYY| I4DC4 I4TM4 I4VE4 I4HE4
 119 //         |YYYY| I4RD4 I4VR4 I4LD4 I4VL4
 120 //         |YY..| I4HD4 I4HU4 I4TMP
 121 //         +----+
 122 #define BPS       16   // this is the common stride
 123 #define Y_SIZE   (BPS * 16)
 124 #define UV_SIZE  (BPS * 8)
 125 #define YUV_SIZE (Y_SIZE + UV_SIZE)
 126 #define PRED_SIZE (6 * 16 * BPS + 12 * BPS)
 127 #define Y_OFF    (0)
 128 #define U_OFF    (Y_SIZE)
 129 #define V_OFF    (U_OFF + 8)
 130 #define ALIGN_CST 15
 131 #define DO_ALIGN(PTR) ((uintptr_t)((PTR) + ALIGN_CST) & ~ALIGN_CST)
 132
 133 extern const int VP8Scan[16 + 4 + 4];           // in quant.c
 134 extern const int VP8UVModeOffsets[4];           // in analyze.c
 135 extern const int VP8I16ModeOffsets[4];
 136 extern const int VP8I4ModeOffsets[NUM_BMODES];
 137
 138 // Layout of prediction blocks
 139 // intra 16x16
 140 #define I16DC16 (0 * 16 * BPS)
 141 #define I16TM16 (1 * 16 * BPS)
 142 #define I16VE16 (2 * 16 * BPS)
 143 #define I16HE16 (3 * 16 * BPS)
 144 // chroma 8x8, two U/V blocks side by side (hence: 16x8 each)
 145 #define C8DC8 (4 * 16 * BPS)
 146 #define C8TM8 (4 * 16 * BPS + 8 * BPS)
 147 #define C8VE8 (5 * 16 * BPS)
 148 #define C8HE8 (5 * 16 * BPS + 8 * BPS)
 149 // intra 4x4
 150 #define I4DC4 (6 * 16 * BPS +  0)
 151 #define I4TM4 (6 * 16 * BPS +  4)
 152 #define I4VE4 (6 * 16 * BPS +  8)
 153 #define I4HE4 (6 * 16 * BPS + 12)
 154 #define I4RD4 (6 * 16 * BPS + 4 * BPS +  0)
 155 #define I4VR4 (6 * 16 * BPS + 4 * BPS +  4)
 156 #define I4LD4 (6 * 16 * BPS + 4 * BPS +  8)
 157 #define I4VL4 (6 * 16 * BPS + 4 * BPS + 12)
 158 #define I4HD4 (6 * 16 * BPS + 8 * BPS +  0)
 159 #define I4HU4 (6 * 16 * BPS + 8 * BPS +  4)
 160 #define I4TMP (6 * 16 * BPS + 8 * BPS +  8)
 161
 162 typedef int64_t score_t;     // type used for scores, rate, distortion
 163 #define MAX_COST ((score_t)0x7fffffffffffffLL)
 164
 165 #define QFIX 17
 166 #define BIAS(b)  ((b) << (QFIX - 8))
 167 // Fun fact: this is the _only_ line where we're actually being lossy and
 168 // discarding bits.
 169 static WEBP_INLINE int QUANTDIV(int n, int iQ, int B) {
 170   return (n * iQ + B) >> QFIX;
 171 }
 172
 173 // size of histogram used by CollectHistogram.
 174 #define MAX_COEFF_THRESH   31
 175 typedef struct VP8Histogram VP8Histogram;
 176 struct VP8Histogram {
 177   // TODO(skal): we only need to store the max_value and last_non_zero actually.
 178   int distribution[MAX_COEFF_THRESH + 1];
 179 };
 180
 181 // Uncomment the following to remove token-buffer code:
 182 // #define DISABLE_TOKEN_BUFFER
 183
 184 //------------------------------------------------------------------------------
 185 // Headers
 186
 187 typedef uint32_t proba_t;   // 16b + 16b
 188 typedef uint8_t ProbaArray[NUM_CTX][NUM_PROBAS];
 189 typedef proba_t StatsArray[NUM_CTX][NUM_PROBAS];
 190 typedef uint16_t CostArray[NUM_CTX][MAX_VARIABLE_LEVEL + 1];
 191 typedef double LFStats[NUM_MB_SEGMENTS][MAX_LF_LEVELS];  // filter stats
 192
 193 typedef struct VP8Encoder VP8Encoder;
 194
 195 // segment features
 196 typedef struct {
 197   int num_segments_;      // Actual number of segments. 1 segment only = unused.
 198   int update_map_;        // whether to update the segment map or not.
 199                           // must be 0 if there's only 1 segment.
 200   int size_;              // bit-cost for transmitting the segment map
 201 } VP8SegmentHeader;
 202
 203 // Struct collecting all frame-persistent probabilities.
 204 typedef struct {
 205   uint8_t segments_[3];     // probabilities for segment tree
 206   uint8_t skip_proba_;      // final probability of being skipped.
 207   ProbaArray coeffs_[NUM_TYPES][NUM_BANDS];      // 924 bytes
 208   StatsArray stats_[NUM_TYPES][NUM_BANDS];       // 4224 bytes
 209   CostArray level_cost_[NUM_TYPES][NUM_BANDS];   // 11.4k
 210   int dirty_;               // if true, need to call VP8CalculateLevelCosts()
 211   int use_skip_proba_;      // Note: we always use skip_proba for now.
 212   int nb_skip_;             // number of skipped blocks
 213 } VP8Proba;
 214
 215 // Filter parameters. Not actually used in the code (we don't perform
 216 // the in-loop filtering), but filled from user's config
 217 typedef struct {
 218   int simple_;             // filtering type: 0=complex, 1=simple
 219   int level_;              // base filter level [0..63]
 220   int sharpness_;          // [0..7]
 221   int i4x4_lf_delta_;      // delta filter level for i4x4 relative to i16x16
 222 } VP8FilterHeader;
 223
 224 //------------------------------------------------------------------------------
 225 // Informations about the macroblocks.
 226
 227 typedef struct {
 228   // block type
 229   unsigned int type_:2;     // 0=i4x4, 1=i16x16
 230   unsigned int uv_mode_:2;
 231   unsigned int skip_:1;
 232   unsigned int segment_:2;
 233   uint8_t alpha_;      // quantization-susceptibility
 234 } VP8MBInfo;
 235
 236 typedef struct VP8Matrix {
 237   uint16_t q_[16];        // quantizer steps
 238   uint16_t iq_[16];       // reciprocals, fixed point.
 239   uint16_t bias_[16];     // rounding bias
 240   uint16_t zthresh_[16];  // value under which a coefficient is zeroed
 241   uint16_t sharpen_[16];  // frequency boosters for slight sharpening
 242 } VP8Matrix;
 243
 244 typedef struct {
 245   VP8Matrix y1_, y2_, uv_;  // quantization matrices
 246   int alpha_;      // quant-susceptibility, range [-127,127]. Zero is neutral.
 247                    // Lower values indicate a lower risk of blurriness.
 248   int beta_;       // filter-susceptibility, range [0,255].
 249   int quant_;      // final segment quantizer.
 250   int fstrength_;  // final in-loop filtering strength
 251   int max_edge_;   // max edge delta (for filtering strength)
 252   int min_disto_;  // minimum distortion required to trigger filtering record
 253   // reactivities
 254   int lambda_i16_, lambda_i4_, lambda_uv_;
 255   int lambda_mode_, lambda_trellis_, tlambda_;
 256   int lambda_trellis_i16_, lambda_trellis_i4_, lambda_trellis_uv_;
 257 } VP8SegmentInfo;
 258
 259 // Handy transient struct to accumulate score and info during RD-optimization
 260 // and mode evaluation.
 261 typedef struct {
 262   score_t D, SD;              // Distortion, spectral distortion
 263   score_t H, R, score;        // header bits, rate, score.
 264   int16_t y_dc_levels[16];    // Quantized levels for luma-DC, luma-AC, chroma.
 265   int16_t y_ac_levels[16][16];
 266   int16_t uv_levels[4 + 4][16];
 267   int mode_i16;               // mode number for intra16 prediction
 268   uint8_t modes_i4[16];       // mode numbers for intra4 predictions
 269   int mode_uv;                // mode number of chroma prediction
 270   uint32_t nz;                // non-zero blocks
 271 } VP8ModeScore;
 272
 273 // Iterator structure to iterate through macroblocks, pointing to the
 274 // right neighbouring data (samples, predictions, contexts, ...)
 275 typedef struct {
 276   int x_, y_;                      // current macroblock
 277   int y_stride_, uv_stride_;       // respective strides
 278   uint8_t*      yuv_in_;           // input samples
 279   uint8_t*      yuv_out_;          // output samples
 280   uint8_t*      yuv_out2_;         // secondary buffer swapped with yuv_out_.
 281   uint8_t*      yuv_p_;            // scratch buffer for prediction
 282   VP8Encoder*   enc_;              // back-pointer
 283   VP8MBInfo*    mb_;               // current macroblock
 284   VP8BitWriter* bw_;               // current bit-writer
 285   uint8_t*      preds_;            // intra mode predictors (4x4 blocks)
 286   uint32_t*     nz_;               // non-zero pattern
 287   uint8_t       i4_boundary_[37];  // 32+5 boundary samples needed by intra4x4
 288   uint8_t*      i4_top_;           // pointer to the current top boundary sample
 289   int           i4_;               // current intra4x4 mode being tested
 290   int           top_nz_[9];        // top-non-zero context.
 291   int           left_nz_[9];       // left-non-zero. left_nz[8] is independent.
 292   uint64_t      bit_count_[4][3];  // bit counters for coded levels.
 293   uint64_t      luma_bits_;        // macroblock bit-cost for luma
 294   uint64_t      uv_bits_;          // macroblock bit-cost for chroma
 295   LFStats*      lf_stats_;         // filter stats (borrowed from enc_)
 296   int           do_trellis_;       // if true, perform extra level optimisation
 297   int           count_down_;       // number of mb still to be processed
 298   int           count_down0_;      // starting counter value (for progress)
 299   int           percent0_;         // saved initial progress percent
 300
 301   uint8_t* y_left_;    // left luma samples (addressable from index -1 to 15).
 302   uint8_t* u_left_;    // left u samples (addressable from index -1 to 7)
 303   uint8_t* v_left_;    // left v samples (addressable from index -1 to 7)
 304
 305   uint8_t* y_top_;     // top luma samples at position 'x_'
 306   uint8_t* uv_top_;    // top u/v samples at position 'x_', packed as 16 bytes
 307
 308   // memory for storing y/u/v_left_ and yuv_in_/out_*
 309   uint8_t yuv_left_mem_[17 + 16 + 16 + 8 + ALIGN_CST];     // memory for *_left_
 310   uint8_t yuv_mem_[3 * YUV_SIZE + PRED_SIZE + ALIGN_CST];  // memory for yuv_*
 311 } VP8EncIterator;
 312
 313   // in iterator.c
 314 // must be called first
 315 void VP8IteratorInit(VP8Encoder* const enc, VP8EncIterator* const it);
 316 // restart a scan
 317 void VP8IteratorReset(VP8EncIterator* const it);
 318 // reset iterator position to row 'y'
 319 void VP8IteratorSetRow(VP8EncIterator* const it, int y);
 320 // set count down (=number of iterations to go)
 321 void VP8IteratorSetCountDown(VP8EncIterator* const it, int count_down);
 322 // return true if iteration is finished
 323 int VP8IteratorIsDone(const VP8EncIterator* const it);
 324 // Import uncompressed samples from source.
 325 // If tmp_32 is not NULL, import boundary samples too.
 326 // tmp_32 is a 32-bytes scratch buffer that must be aligned in memory.
 327 void VP8IteratorImport(VP8EncIterator* const it, uint8_t* tmp_32);
 328 // export decimated samples
 329 void VP8IteratorExport(const VP8EncIterator* const it);
 330 // go to next macroblock. Returns false if not finished.
 331 int VP8IteratorNext(VP8EncIterator* const it);
 332 // save the yuv_out_ boundary values to top_/left_ arrays for next iterations.
 333 void VP8IteratorSaveBoundary(VP8EncIterator* const it);
 334 // Report progression based on macroblock rows. Return 0 for user-abort request.
 335 int VP8IteratorProgress(const VP8EncIterator* const it,
 336                         int final_delta_percent);
 337 // Intra4x4 iterations
 338 void VP8IteratorStartI4(VP8EncIterator* const it);
 339 // returns true if not done.
 340 int VP8IteratorRotateI4(VP8EncIterator* const it,
 341                         const uint8_t* const yuv_out);
 342
 343 // Non-zero context setup/teardown
 344 void VP8IteratorNzToBytes(VP8EncIterator* const it);
 345 void VP8IteratorBytesToNz(VP8EncIterator* const it);
 346
 347 // Helper functions to set mode properties
 348 void VP8SetIntra16Mode(const VP8EncIterator* const it, int mode);
 349 void VP8SetIntra4Mode(const VP8EncIterator* const it, const uint8_t* modes);
 350 void VP8SetIntraUVMode(const VP8EncIterator* const it, int mode);
 351 void VP8SetSkip(const VP8EncIterator* const it, int skip);
 352 void VP8SetSegment(const VP8EncIterator* const it, int segment);
 353
 354 //------------------------------------------------------------------------------
 355 // Paginated token buffer
 356
 357 typedef struct VP8Tokens VP8Tokens;  // struct details in token.c
 358
 359 typedef struct {
 360 #if !defined(DISABLE_TOKEN_BUFFER)
 361   VP8Tokens* pages_;        // first page
 362   VP8Tokens** last_page_;   // last page
 363   uint16_t* tokens_;        // set to (*last_page_)->tokens_
 364   int left_;          // how many free tokens left before the page is full.
 365 #endif
 366   int error_;         // true in case of malloc error
 367 } VP8TBuffer;
 368
 369 void VP8TBufferInit(VP8TBuffer* const b);    // initialize an empty buffer
 370 void VP8TBufferClear(VP8TBuffer* const b);   // de-allocate pages memory
 371
 372 #if !defined(DISABLE_TOKEN_BUFFER)
 373
 374 // Finalizes bitstream when probabilities are known.
 375 // Deletes the allocated token memory if final_pass is true.
 376 int VP8EmitTokens(VP8TBuffer* const b, VP8BitWriter* const bw,
 377                   const uint8_t* const probas, int final_pass);
 378
 379 // record the coding of coefficients without knowing the probabilities yet
 380 int VP8RecordCoeffTokens(int ctx, int coeff_type, int first, int last,
 381                          const int16_t* const coeffs,
 382                          VP8TBuffer* const tokens);
 383
 384 // Estimate the final coded size given a set of 'probas'.
 385 size_t VP8EstimateTokenSize(VP8TBuffer* const b, const uint8_t* const probas);
 386
 387 // unused for now
 388 void VP8TokenToStats(const VP8TBuffer* const b, proba_t* const stats);
 389
 390 #endif  // !DISABLE_TOKEN_BUFFER
 391
 392 //------------------------------------------------------------------------------
 393 // VP8Encoder
 394
 395 struct VP8Encoder {
 396   const WebPConfig* config_;    // user configuration and parameters
 397   WebPPicture* pic_;            // input / output picture
 398
 399   // headers
 400   VP8FilterHeader   filter_hdr_;     // filtering information
 401   VP8SegmentHeader  segment_hdr_;    // segment information
 402
 403   int profile_;                      // VP8's profile, deduced from Config.
 404
 405   // dimension, in macroblock units.
 406   int mb_w_, mb_h_;
 407   int preds_w_;   // stride of the *preds_ prediction plane (=4*mb_w + 1)
 408
 409   // number of partitions (1, 2, 4 or 8 = MAX_NUM_PARTITIONS)
 410   int num_parts_;
 411
 412   // per-partition boolean decoders.
 413   VP8BitWriter bw_;                         // part0
 414   VP8BitWriter parts_[MAX_NUM_PARTITIONS];  // token partitions
 415   VP8TBuffer tokens_;                       // token buffer
 416
 417   int percent_;                             // for progress
 418
 419   // transparency blob
 420   int has_alpha_;
 421   uint8_t* alpha_data_;       // non-NULL if transparency is present
 422   uint32_t alpha_data_size_;
 423   WebPWorker alpha_worker_;
 424
 425   // enhancement layer
 426   int use_layer_;
 427   VP8BitWriter layer_bw_;
 428   uint8_t* layer_data_;
 429   size_t layer_data_size_;
 430
 431   // quantization info (one set of DC/AC dequant factor per segment)
 432   VP8SegmentInfo dqm_[NUM_MB_SEGMENTS];
 433   int base_quant_;                 // nominal quantizer value. Only used
 434                                    // for relative coding of segments' quant.
 435   int alpha_;                      // global susceptibility (<=> complexity)
 436   int uv_alpha_;                   // U/V quantization susceptibility
 437   // global offset of quantizers, shared by all segments
 438   int dq_y1_dc_;
 439   int dq_y2_dc_, dq_y2_ac_;
 440   int dq_uv_dc_, dq_uv_ac_;
 441
 442   // probabilities and statistics
 443   VP8Proba proba_;
 444   uint64_t sse_[4];        // sum of Y/U/V/A squared errors for all macroblocks
 445   uint64_t sse_count_;     // pixel count for the sse_[] stats
 446   int      coded_size_;
 447   int      residual_bytes_[3][4];
 448   int      block_count_[3];
 449
 450   // quality/speed settings
 451   int method_;               // 0=fastest, 6=best/slowest.
 452   VP8RDLevel rd_opt_level_;  // Deduced from method_.
 453   int max_i4_header_bits_;   // partition #0 safeness factor
 454   int thread_level_;         // derived from config->thread_level
 455   int do_search_;            // derived from config->target_XXX
 456   int use_tokens_;           // if true, use token buffer
 457
 458   // Memory
 459   VP8MBInfo* mb_info_;   // contextual macroblock infos (mb_w_ + 1)
 460   uint8_t*   preds_;     // predictions modes: (4*mb_w+1) * (4*mb_h+1)
 461   uint32_t*  nz_;        // non-zero bit context: mb_w+1
 462   uint8_t   *y_top_;     // top luma samples.
 463   uint8_t   *uv_top_;    // top u/v samples.
 464                          // U and V are packed into 16 bytes (8 U + 8 V)
 465   LFStats   *lf_stats_;  // autofilter stats (if NULL, autofilter is off)
 466 };
 467
 468 //------------------------------------------------------------------------------
 469 // internal functions. Not public.
 470
 471   // in tree.c
 472 extern const uint8_t VP8CoeffsProba0[NUM_TYPES][NUM_BANDS][NUM_CTX][NUM_PROBAS];
 473 extern const uint8_t
 474     VP8CoeffsUpdateProba[NUM_TYPES][NUM_BANDS][NUM_CTX][NUM_PROBAS];
 475 // Reset the token probabilities to their initial (default) values
 476 void VP8DefaultProbas(VP8Encoder* const enc);
 477 // Write the token probabilities
 478 void VP8WriteProbas(VP8BitWriter* const bw, const VP8Proba* const probas);
 479 // Writes the partition #0 modes (that is: all intra modes)
 480 void VP8CodeIntraModes(VP8Encoder* const enc);
 481
 482   // in syntax.c
 483 // Generates the final bitstream by coding the partition0 and headers,
 484 // and appending an assembly of all the pre-coded token partitions.
 485 // Return true if everything is ok.
 486 int VP8EncWrite(VP8Encoder* const enc);
 487 // Release memory allocated for bit-writing in VP8EncLoop & seq.
 488 void VP8EncFreeBitWriters(VP8Encoder* const enc);
 489
 490   // in frame.c
 491 extern const uint8_t VP8EncBands[16 + 1];
 492 extern const uint8_t VP8Cat3[];
 493 extern const uint8_t VP8Cat4[];
 494 extern const uint8_t VP8Cat5[];
 495 extern const uint8_t VP8Cat6[];
 496
 497 // Form all the four Intra16x16 predictions in the yuv_p_ cache
 498 void VP8MakeLuma16Preds(const VP8EncIterator* const it);
 499 // Form all the four Chroma8x8 predictions in the yuv_p_ cache
 500 void VP8MakeChroma8Preds(const VP8EncIterator* const it);
 501 // Form all the ten Intra4x4 predictions in the yuv_p_ cache
 502 // for the 4x4 block it->i4_
 503 void VP8MakeIntra4Preds(const VP8EncIterator* const it);
 504 // Rate calculation
 505 int VP8GetCostLuma16(VP8EncIterator* const it, const VP8ModeScore* const rd);
 506 int VP8GetCostLuma4(VP8EncIterator* const it, const int16_t levels[16]);
 507 int VP8GetCostUV(VP8EncIterator* const it, const VP8ModeScore* const rd);
 508 // Main coding calls
 509 int VP8EncLoop(VP8Encoder* const enc);
 510 int VP8EncTokenLoop(VP8Encoder* const enc);
 511
 512   // in webpenc.c
 513 // Assign an error code to a picture. Return false for convenience.
 514 int WebPEncodingSetError(const WebPPicture* const pic, WebPEncodingError error);
 515 int WebPReportProgress(const WebPPicture* const pic,
 516                        int percent, int* const percent_store);
 517
 518   // in analysis.c
 519 // Main analysis loop. Decides the segmentations and complexity.
 520 // Assigns a first guess for Intra16 and uvmode_ prediction modes.
 521 int VP8EncAnalyze(VP8Encoder* const enc);
 522
 523   // in quant.c
 524 // Sets up segment's quantization values, base_quant_ and filter strengths.
 525 void VP8SetSegmentParams(VP8Encoder* const enc, float quality);
 526 // Pick best modes and fills the levels. Returns true if skipped.
 527 int VP8Decimate(VP8EncIterator* const it, VP8ModeScore* const rd,
 528                 VP8RDLevel rd_opt);
 529
 530   // in alpha.c
 531 void VP8EncInitAlpha(VP8Encoder* const enc);    // initialize alpha compression
 532 int VP8EncStartAlpha(VP8Encoder* const enc);    // start alpha coding process
 533 int VP8EncFinishAlpha(VP8Encoder* const enc);   // finalize compressed data
 534 int VP8EncDeleteAlpha(VP8Encoder* const enc);   // delete compressed data
 535
 536   // in layer.c
 537 void VP8EncInitLayer(VP8Encoder* const enc);     // init everything
 538 void VP8EncCodeLayerBlock(VP8EncIterator* it);   // code one more macroblock
 539 int VP8EncFinishLayer(VP8Encoder* const enc);    // finalize coding
 540 void VP8EncDeleteLayer(VP8Encoder* enc);         // reclaim memory
 541
 542   // in filter.c
 543
 544 // SSIM utils
 545 typedef struct {
 546   double w, xm, ym, xxm, xym, yym;
 547 } DistoStats;
 548 void VP8SSIMAddStats(const DistoStats* const src, DistoStats* const dst);
 549 void VP8SSIMAccumulatePlane(const uint8_t* src1, int stride1,
 550                             const uint8_t* src2, int stride2,
 551                             int W, int H, DistoStats* const stats);
 552 double VP8SSIMGet(const DistoStats* const stats);
 553 double VP8SSIMGetSquaredError(const DistoStats* const stats);
 554
 555 // autofilter
 556 void VP8InitFilter(VP8EncIterator* const it);
 557 void VP8StoreFilterStats(VP8EncIterator* const it);
 558 void VP8AdjustFilterStrength(VP8EncIterator* const it);
 559
 560 // returns the approximate filtering strength needed to smooth a edge
 561 // step of 'delta', given a sharpness parameter 'sharpness'.
 562 int VP8FilterStrengthFromDelta(int sharpness, int delta);
 563
 564 //------------------------------------------------------------------------------
 565
 566 #ifdef __cplusplus
 567 }    // extern "C"
 568 #endif
 569
 570 #endif  /* WEBP_ENC_VP8ENCI_H_ */