Coverage Report

Created: 2024-07-27 06:27

/src/libwebp/src/enc/vp8i_enc.h
Line
Count
Source (jump to first uncovered line)
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_VP8I_ENC_H_
15
#define WEBP_ENC_VP8I_ENC_H_
16
17
#include <string.h>     // for memcpy()
18
#include "src/dec/common_dec.h"
19
#include "src/dsp/dsp.h"
20
#include "src/utils/bit_writer_utils.h"
21
#include "src/utils/thread_utils.h"
22
#include "src/utils/utils.h"
23
#include "src/webp/encode.h"
24
25
#ifdef __cplusplus
26
extern "C" {
27
#endif
28
29
//------------------------------------------------------------------------------
30
// Various defines and enums
31
32
// version numbers
33
0
#define ENC_MAJ_VERSION 1
34
0
#define ENC_MIN_VERSION 4
35
0
#define ENC_REV_VERSION 0
36
37
enum { MAX_LF_LEVELS = 64,       // Maximum loop filter level
38
       MAX_VARIABLE_LEVEL = 67,  // last (inclusive) level with variable cost
39
       MAX_LEVEL = 2047          // max level (note: max codable is 2047 + 67)
40
     };
41
42
typedef enum {   // Rate-distortion optimization levels
43
  RD_OPT_NONE        = 0,  // no rd-opt
44
  RD_OPT_BASIC       = 1,  // basic scoring (no trellis)
45
  RD_OPT_TRELLIS     = 2,  // perform trellis-quant on the final decision only
46
  RD_OPT_TRELLIS_ALL = 3   // trellis-quant for every scoring (much slower)
47
} VP8RDLevel;
48
49
// YUV-cache parameters. Cache is 32-bytes wide (= one cacheline).
50
// The original or reconstructed samples can be accessed using VP8Scan[].
51
// The predicted blocks can be accessed using offsets to yuv_p_ and
52
// the arrays VP8*ModeOffsets[].
53
// * YUV Samples area (yuv_in_/yuv_out_/yuv_out2_)
54
//   (see VP8Scan[] for accessing the blocks, along with
55
//   Y_OFF_ENC/U_OFF_ENC/V_OFF_ENC):
56
//             +----+----+
57
//  Y_OFF_ENC  |YYYY|UUVV|
58
//  U_OFF_ENC  |YYYY|UUVV|
59
//  V_OFF_ENC  |YYYY|....| <- 25% wasted U/V area
60
//             |YYYY|....|
61
//             +----+----+
62
// * Prediction area ('yuv_p_', size = PRED_SIZE_ENC)
63
//   Intra16 predictions (16x16 block each, two per row):
64
//         |I16DC16|I16TM16|
65
//         |I16VE16|I16HE16|
66
//   Chroma U/V predictions (16x8 block each, two per row):
67
//         |C8DC8|C8TM8|
68
//         |C8VE8|C8HE8|
69
//   Intra 4x4 predictions (4x4 block each)
70
//         |I4DC4 I4TM4 I4VE4 I4HE4|I4RD4 I4VR4 I4LD4 I4VL4|
71
//         |I4HD4 I4HU4 I4TMP .....|.......................| <- ~31% wasted
72
0
#define YUV_SIZE_ENC (BPS * 16)
73
#define PRED_SIZE_ENC (32 * BPS + 16 * BPS + 8 * BPS)   // I16+Chroma+I4 preds
74
0
#define Y_OFF_ENC    (0)
75
0
#define U_OFF_ENC    (16)
76
0
#define V_OFF_ENC    (16 + 8)
77
78
extern const uint16_t VP8Scan[16];
79
extern const uint16_t VP8UVModeOffsets[4];
80
extern const uint16_t VP8I16ModeOffsets[4];
81
82
// Layout of prediction blocks
83
// intra 16x16
84
0
#define I16DC16 (0 * 16 * BPS)
85
0
#define I16TM16 (I16DC16 + 16)
86
0
#define I16VE16 (1 * 16 * BPS)
87
0
#define I16HE16 (I16VE16 + 16)
88
// chroma 8x8, two U/V blocks side by side (hence: 16x8 each)
89
0
#define C8DC8 (2 * 16 * BPS)
90
0
#define C8TM8 (C8DC8 + 1 * 16)
91
0
#define C8VE8 (2 * 16 * BPS + 8 * BPS)
92
0
#define C8HE8 (C8VE8 + 1 * 16)
93
// intra 4x4
94
0
#define I4DC4 (3 * 16 * BPS +  0)
95
0
#define I4TM4 (I4DC4 +  4)
96
0
#define I4VE4 (I4DC4 +  8)
97
0
#define I4HE4 (I4DC4 + 12)
98
0
#define I4RD4 (I4DC4 + 16)
99
0
#define I4VR4 (I4DC4 + 20)
100
0
#define I4LD4 (I4DC4 + 24)
101
0
#define I4VL4 (I4DC4 + 28)
102
0
#define I4HD4 (3 * 16 * BPS + 4 * BPS)
103
0
#define I4HU4 (I4HD4 + 4)
104
0
#define I4TMP (I4HD4 + 8)
105
106
typedef int64_t score_t;     // type used for scores, rate, distortion
107
// Note that MAX_COST is not the maximum allowed by sizeof(score_t),
108
// in order to allow overflowing computations.
109
0
#define MAX_COST ((score_t)0x7fffffffffffffLL)
110
111
0
#define QFIX 17
112
0
#define BIAS(b)  ((b) << (QFIX - 8))
113
// Fun fact: this is the _only_ line where we're actually being lossy and
114
// discarding bits.
115
0
static WEBP_INLINE int QUANTDIV(uint32_t n, uint32_t iQ, uint32_t B) {
116
0
  return (int)((n * iQ + B) >> QFIX);
117
0
}
Unexecuted instantiation: picture_enc.c:QUANTDIV
Unexecuted instantiation: webp_enc.c:QUANTDIV
Unexecuted instantiation: cost.c:QUANTDIV
Unexecuted instantiation: enc.c:QUANTDIV
Unexecuted instantiation: cost_sse2.c:QUANTDIV
Unexecuted instantiation: enc_sse2.c:QUANTDIV
Unexecuted instantiation: enc_sse41.c:QUANTDIV
Unexecuted instantiation: alpha_enc.c:QUANTDIV
Unexecuted instantiation: analysis_enc.c:QUANTDIV
Unexecuted instantiation: frame_enc.c:QUANTDIV
Unexecuted instantiation: iterator_enc.c:QUANTDIV
Unexecuted instantiation: picture_csp_enc.c:QUANTDIV
Unexecuted instantiation: picture_tools_enc.c:QUANTDIV
Unexecuted instantiation: quant_enc.c:QUANTDIV
Unexecuted instantiation: syntax_enc.c:QUANTDIV
Unexecuted instantiation: token_enc.c:QUANTDIV
Unexecuted instantiation: tree_enc.c:QUANTDIV
Unexecuted instantiation: vp8l_enc.c:QUANTDIV
Unexecuted instantiation: backward_references_enc.c:QUANTDIV
Unexecuted instantiation: cost_enc.c:QUANTDIV
Unexecuted instantiation: filter_enc.c:QUANTDIV
Unexecuted instantiation: histogram_enc.c:QUANTDIV
Unexecuted instantiation: picture_rescale_enc.c:QUANTDIV
Unexecuted instantiation: predictor_enc.c:QUANTDIV
118
119
// Uncomment the following to remove token-buffer code:
120
// #define DISABLE_TOKEN_BUFFER
121
122
// quality below which error-diffusion is enabled
123
0
#define ERROR_DIFFUSION_QUALITY 98
124
125
//------------------------------------------------------------------------------
126
// Headers
127
128
typedef uint32_t proba_t;   // 16b + 16b
129
typedef uint8_t ProbaArray[NUM_CTX][NUM_PROBAS];
130
typedef proba_t StatsArray[NUM_CTX][NUM_PROBAS];
131
typedef uint16_t CostArray[NUM_CTX][MAX_VARIABLE_LEVEL + 1];
132
typedef const uint16_t* (*CostArrayPtr)[NUM_CTX];   // for easy casting
133
typedef const uint16_t* CostArrayMap[16][NUM_CTX];
134
typedef double LFStats[NUM_MB_SEGMENTS][MAX_LF_LEVELS];  // filter stats
135
136
typedef struct VP8Encoder VP8Encoder;
137
138
// segment features
139
typedef struct {
140
  int num_segments_;      // Actual number of segments. 1 segment only = unused.
141
  int update_map_;        // whether to update the segment map or not.
142
                          // must be 0 if there's only 1 segment.
143
  int size_;              // bit-cost for transmitting the segment map
144
} VP8EncSegmentHeader;
145
146
// Struct collecting all frame-persistent probabilities.
147
typedef struct {
148
  uint8_t segments_[3];     // probabilities for segment tree
149
  uint8_t skip_proba_;      // final probability of being skipped.
150
  ProbaArray coeffs_[NUM_TYPES][NUM_BANDS];      // 1056 bytes
151
  StatsArray stats_[NUM_TYPES][NUM_BANDS];       // 4224 bytes
152
  CostArray level_cost_[NUM_TYPES][NUM_BANDS];   // 13056 bytes
153
  CostArrayMap remapped_costs_[NUM_TYPES];       // 1536 bytes
154
  int dirty_;               // if true, need to call VP8CalculateLevelCosts()
155
  int use_skip_proba_;      // Note: we always use skip_proba for now.
156
  int nb_skip_;             // number of skipped blocks
157
} VP8EncProba;
158
159
// Filter parameters. Not actually used in the code (we don't perform
160
// the in-loop filtering), but filled from user's config
161
typedef struct {
162
  int simple_;             // filtering type: 0=complex, 1=simple
163
  int level_;              // base filter level [0..63]
164
  int sharpness_;          // [0..7]
165
  int i4x4_lf_delta_;      // delta filter level for i4x4 relative to i16x16
166
} VP8EncFilterHeader;
167
168
//------------------------------------------------------------------------------
169
// Informations about the macroblocks.
170
171
typedef struct {
172
  // block type
173
  unsigned int type_:2;     // 0=i4x4, 1=i16x16
174
  unsigned int uv_mode_:2;
175
  unsigned int skip_:1;
176
  unsigned int segment_:2;
177
  uint8_t alpha_;      // quantization-susceptibility
178
} VP8MBInfo;
179
180
typedef struct VP8Matrix {
181
  uint16_t q_[16];        // quantizer steps
182
  uint16_t iq_[16];       // reciprocals, fixed point.
183
  uint32_t bias_[16];     // rounding bias
184
  uint32_t zthresh_[16];  // value below which a coefficient is zeroed
185
  uint16_t sharpen_[16];  // frequency boosters for slight sharpening
186
} VP8Matrix;
187
188
typedef struct {
189
  VP8Matrix y1_, y2_, uv_;  // quantization matrices
190
  int alpha_;      // quant-susceptibility, range [-127,127]. Zero is neutral.
191
                   // Lower values indicate a lower risk of blurriness.
192
  int beta_;       // filter-susceptibility, range [0,255].
193
  int quant_;      // final segment quantizer.
194
  int fstrength_;  // final in-loop filtering strength
195
  int max_edge_;   // max edge delta (for filtering strength)
196
  int min_disto_;  // minimum distortion required to trigger filtering record
197
  // reactivities
198
  int lambda_i16_, lambda_i4_, lambda_uv_;
199
  int lambda_mode_, lambda_trellis_, tlambda_;
200
  int lambda_trellis_i16_, lambda_trellis_i4_, lambda_trellis_uv_;
201
202
  // lambda values for distortion-based evaluation
203
  score_t i4_penalty_;   // penalty for using Intra4
204
} VP8SegmentInfo;
205
206
typedef int8_t DError[2 /* u/v */][2 /* top or left */];
207
208
// Handy transient struct to accumulate score and info during RD-optimization
209
// and mode evaluation.
210
typedef struct {
211
  score_t D, SD;              // Distortion, spectral distortion
212
  score_t H, R, score;        // header bits, rate, score.
213
  int16_t y_dc_levels[16];    // Quantized levels for luma-DC, luma-AC, chroma.
214
  int16_t y_ac_levels[16][16];
215
  int16_t uv_levels[4 + 4][16];
216
  int mode_i16;               // mode number for intra16 prediction
217
  uint8_t modes_i4[16];       // mode numbers for intra4 predictions
218
  int mode_uv;                // mode number of chroma prediction
219
  uint32_t nz;                // non-zero blocks
220
  int8_t derr[2][3];          // DC diffusion errors for U/V for blocks #1/2/3
221
} VP8ModeScore;
222
223
// Iterator structure to iterate through macroblocks, pointing to the
224
// right neighbouring data (samples, predictions, contexts, ...)
225
typedef struct {
226
  int x_, y_;                      // current macroblock
227
  uint8_t*      yuv_in_;           // input samples
228
  uint8_t*      yuv_out_;          // output samples
229
  uint8_t*      yuv_out2_;         // secondary buffer swapped with yuv_out_.
230
  uint8_t*      yuv_p_;            // scratch buffer for prediction
231
  VP8Encoder*   enc_;              // back-pointer
232
  VP8MBInfo*    mb_;               // current macroblock
233
  VP8BitWriter* bw_;               // current bit-writer
234
  uint8_t*      preds_;            // intra mode predictors (4x4 blocks)
235
  uint32_t*     nz_;               // non-zero pattern
236
  uint8_t       i4_boundary_[37];  // 32+5 boundary samples needed by intra4x4
237
  uint8_t*      i4_top_;           // pointer to the current top boundary sample
238
  int           i4_;               // current intra4x4 mode being tested
239
  int           top_nz_[9];        // top-non-zero context.
240
  int           left_nz_[9];       // left-non-zero. left_nz[8] is independent.
241
  uint64_t      bit_count_[4][3];  // bit counters for coded levels.
242
  uint64_t      luma_bits_;        // macroblock bit-cost for luma
243
  uint64_t      uv_bits_;          // macroblock bit-cost for chroma
244
  LFStats*      lf_stats_;         // filter stats (borrowed from enc_)
245
  int           do_trellis_;       // if true, perform extra level optimisation
246
  int           count_down_;       // number of mb still to be processed
247
  int           count_down0_;      // starting counter value (for progress)
248
  int           percent0_;         // saved initial progress percent
249
250
  DError        left_derr_;        // left error diffusion (u/v)
251
  DError*       top_derr_;         // top diffusion error - NULL if disabled
252
253
  uint8_t* y_left_;    // left luma samples (addressable from index -1 to 15).
254
  uint8_t* u_left_;    // left u samples (addressable from index -1 to 7)
255
  uint8_t* v_left_;    // left v samples (addressable from index -1 to 7)
256
257
  uint8_t* y_top_;     // top luma samples at position 'x_'
258
  uint8_t* uv_top_;    // top u/v samples at position 'x_', packed as 16 bytes
259
260
  // memory for storing y/u/v_left_
261
  uint8_t yuv_left_mem_[17 + 16 + 16 + 8 + WEBP_ALIGN_CST];
262
  // memory for yuv_*
263
  uint8_t yuv_mem_[3 * YUV_SIZE_ENC + PRED_SIZE_ENC + WEBP_ALIGN_CST];
264
} VP8EncIterator;
265
266
  // in iterator.c
267
// must be called first
268
void VP8IteratorInit(VP8Encoder* const enc, VP8EncIterator* const it);
269
// reset iterator position to row 'y'
270
void VP8IteratorSetRow(VP8EncIterator* const it, int y);
271
// set count down (=number of iterations to go)
272
void VP8IteratorSetCountDown(VP8EncIterator* const it, int count_down);
273
// return true if iteration is finished
274
int VP8IteratorIsDone(const VP8EncIterator* const it);
275
// Import uncompressed samples from source.
276
// If tmp_32 is not NULL, import boundary samples too.
277
// tmp_32 is a 32-bytes scratch buffer that must be aligned in memory.
278
void VP8IteratorImport(VP8EncIterator* const it, uint8_t* const tmp_32);
279
// export decimated samples
280
void VP8IteratorExport(const VP8EncIterator* const it);
281
// go to next macroblock. Returns false if not finished.
282
int VP8IteratorNext(VP8EncIterator* const it);
283
// save the yuv_out_ boundary values to top_/left_ arrays for next iterations.
284
void VP8IteratorSaveBoundary(VP8EncIterator* const it);
285
// Report progression based on macroblock rows. Return 0 for user-abort request.
286
int VP8IteratorProgress(const VP8EncIterator* const it, int delta);
287
// Intra4x4 iterations
288
void VP8IteratorStartI4(VP8EncIterator* const it);
289
// returns true if not done.
290
int VP8IteratorRotateI4(VP8EncIterator* const it,
291
                        const uint8_t* const yuv_out);
292
293
// Non-zero context setup/teardown
294
void VP8IteratorNzToBytes(VP8EncIterator* const it);
295
void VP8IteratorBytesToNz(VP8EncIterator* const it);
296
297
// Helper functions to set mode properties
298
void VP8SetIntra16Mode(const VP8EncIterator* const it, int mode);
299
void VP8SetIntra4Mode(const VP8EncIterator* const it, const uint8_t* modes);
300
void VP8SetIntraUVMode(const VP8EncIterator* const it, int mode);
301
void VP8SetSkip(const VP8EncIterator* const it, int skip);
302
void VP8SetSegment(const VP8EncIterator* const it, int segment);
303
304
//------------------------------------------------------------------------------
305
// Paginated token buffer
306
307
typedef struct VP8Tokens VP8Tokens;  // struct details in token.c
308
309
typedef struct {
310
#if !defined(DISABLE_TOKEN_BUFFER)
311
  VP8Tokens* pages_;        // first page
312
  VP8Tokens** last_page_;   // last page
313
  uint16_t* tokens_;        // set to (*last_page_)->tokens_
314
  int left_;                // how many free tokens left before the page is full
315
  int page_size_;           // number of tokens per page
316
#endif
317
  int error_;         // true in case of malloc error
318
} VP8TBuffer;
319
320
// initialize an empty buffer
321
void VP8TBufferInit(VP8TBuffer* const b, int page_size);
322
void VP8TBufferClear(VP8TBuffer* const b);   // de-allocate pages memory
323
324
#if !defined(DISABLE_TOKEN_BUFFER)
325
326
// Finalizes bitstream when probabilities are known.
327
// Deletes the allocated token memory if final_pass is true.
328
int VP8EmitTokens(VP8TBuffer* const b, VP8BitWriter* const bw,
329
                  const uint8_t* const probas, int final_pass);
330
331
// record the coding of coefficients without knowing the probabilities yet
332
int VP8RecordCoeffTokens(int ctx, const struct VP8Residual* const res,
333
                         VP8TBuffer* const tokens);
334
335
// Estimate the final coded size given a set of 'probas'.
336
size_t VP8EstimateTokenSize(VP8TBuffer* const b, const uint8_t* const probas);
337
338
#endif  // !DISABLE_TOKEN_BUFFER
339
340
//------------------------------------------------------------------------------
341
// VP8Encoder
342
343
struct VP8Encoder {
344
  const WebPConfig* config_;    // user configuration and parameters
345
  WebPPicture* pic_;            // input / output picture
346
347
  // headers
348
  VP8EncFilterHeader   filter_hdr_;     // filtering information
349
  VP8EncSegmentHeader  segment_hdr_;    // segment information
350
351
  int profile_;                      // VP8's profile, deduced from Config.
352
353
  // dimension, in macroblock units.
354
  int mb_w_, mb_h_;
355
  int preds_w_;   // stride of the *preds_ prediction plane (=4*mb_w + 1)
356
357
  // number of partitions (1, 2, 4 or 8 = MAX_NUM_PARTITIONS)
358
  int num_parts_;
359
360
  // per-partition boolean decoders.
361
  VP8BitWriter bw_;                         // part0
362
  VP8BitWriter parts_[MAX_NUM_PARTITIONS];  // token partitions
363
  VP8TBuffer tokens_;                       // token buffer
364
365
  int percent_;                             // for progress
366
367
  // transparency blob
368
  int has_alpha_;
369
  uint8_t* alpha_data_;       // non-NULL if transparency is present
370
  uint32_t alpha_data_size_;
371
  WebPWorker alpha_worker_;
372
373
  // quantization info (one set of DC/AC dequant factor per segment)
374
  VP8SegmentInfo dqm_[NUM_MB_SEGMENTS];
375
  int base_quant_;                 // nominal quantizer value. Only used
376
                                   // for relative coding of segments' quant.
377
  int alpha_;                      // global susceptibility (<=> complexity)
378
  int uv_alpha_;                   // U/V quantization susceptibility
379
  // global offset of quantizers, shared by all segments
380
  int dq_y1_dc_;
381
  int dq_y2_dc_, dq_y2_ac_;
382
  int dq_uv_dc_, dq_uv_ac_;
383
384
  // probabilities and statistics
385
  VP8EncProba proba_;
386
  uint64_t    sse_[4];      // sum of Y/U/V/A squared errors for all macroblocks
387
  uint64_t    sse_count_;   // pixel count for the sse_[] stats
388
  int         coded_size_;
389
  int         residual_bytes_[3][4];
390
  int         block_count_[3];
391
392
  // quality/speed settings
393
  int method_;               // 0=fastest, 6=best/slowest.
394
  VP8RDLevel rd_opt_level_;  // Deduced from method_.
395
  int max_i4_header_bits_;   // partition #0 safeness factor
396
  int mb_header_limit_;      // rough limit for header bits per MB
397
  int thread_level_;         // derived from config->thread_level
398
  int do_search_;            // derived from config->target_XXX
399
  int use_tokens_;           // if true, use token buffer
400
401
  // Memory
402
  VP8MBInfo* mb_info_;   // contextual macroblock infos (mb_w_ + 1)
403
  uint8_t*   preds_;     // predictions modes: (4*mb_w+1) * (4*mb_h+1)
404
  uint32_t*  nz_;        // non-zero bit context: mb_w+1
405
  uint8_t*   y_top_;     // top luma samples.
406
  uint8_t*   uv_top_;    // top u/v samples.
407
                         // U and V are packed into 16 bytes (8 U + 8 V)
408
  LFStats*   lf_stats_;  // autofilter stats (if NULL, autofilter is off)
409
  DError*    top_derr_;  // diffusion error (NULL if disabled)
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
// Rate calculation
445
int VP8GetCostLuma16(VP8EncIterator* const it, const VP8ModeScore* const rd);
446
int VP8GetCostLuma4(VP8EncIterator* const it, const int16_t levels[16]);
447
int VP8GetCostUV(VP8EncIterator* const it, const VP8ModeScore* const rd);
448
// Main coding calls
449
int VP8EncLoop(VP8Encoder* const enc);
450
int VP8EncTokenLoop(VP8Encoder* const enc);
451
452
  // in webpenc.c
453
// Assign an error code to a picture. Return false for convenience.
454
int WebPEncodingSetError(const WebPPicture* const pic, WebPEncodingError error);
455
int WebPReportProgress(const WebPPicture* const pic,
456
                       int percent, int* const percent_store);
457
458
  // in analysis.c
459
// Main analysis loop. Decides the segmentations and complexity.
460
// Assigns a first guess for Intra16 and uvmode_ prediction modes.
461
int VP8EncAnalyze(VP8Encoder* const enc);
462
463
  // in quant.c
464
// Sets up segment's quantization values, base_quant_ and filter strengths.
465
void VP8SetSegmentParams(VP8Encoder* const enc, float quality);
466
// Pick best modes and fills the levels. Returns true if skipped.
467
int VP8Decimate(VP8EncIterator* WEBP_RESTRICT const it,
468
                VP8ModeScore* WEBP_RESTRICT const rd,
469
                VP8RDLevel rd_opt);
470
471
  // in alpha.c
472
void VP8EncInitAlpha(VP8Encoder* const enc);    // initialize alpha compression
473
int VP8EncStartAlpha(VP8Encoder* const enc);    // start alpha coding process
474
int VP8EncFinishAlpha(VP8Encoder* const enc);   // finalize compressed data
475
int VP8EncDeleteAlpha(VP8Encoder* const enc);   // delete compressed data
476
477
// autofilter
478
void VP8InitFilter(VP8EncIterator* const it);
479
void VP8StoreFilterStats(VP8EncIterator* const it);
480
void VP8AdjustFilterStrength(VP8EncIterator* const it);
481
482
// returns the approximate filtering strength needed to smooth a edge
483
// step of 'delta', given a sharpness parameter 'sharpness'.
484
int VP8FilterStrengthFromDelta(int sharpness, int delta);
485
486
  // misc utils for picture_*.c:
487
488
// Returns true if 'picture' is non-NULL and dimensions/colorspace are within
489
// their valid ranges. If returning false, the 'error_code' in 'picture' is
490
// updated.
491
int WebPValidatePicture(const WebPPicture* const picture);
492
493
// Remove reference to the ARGB/YUVA buffer (doesn't free anything).
494
void WebPPictureResetBuffers(WebPPicture* const picture);
495
496
// Allocates ARGB buffer according to set width/height (previous one is
497
// always free'd). Preserves the YUV(A) buffer. Returns false in case of error
498
// (invalid param, out-of-memory).
499
int WebPPictureAllocARGB(WebPPicture* const picture);
500
501
// Allocates YUVA buffer according to set width/height (previous one is always
502
// free'd). Uses picture->csp to determine whether an alpha buffer is needed.
503
// Preserves the ARGB buffer.
504
// Returns false in case of error (invalid param, out-of-memory).
505
int WebPPictureAllocYUVA(WebPPicture* const picture);
506
507
// Replace samples that are fully transparent by 'color' to help compressibility
508
// (no guarantee, though). Assumes pic->use_argb is true.
509
void WebPReplaceTransparentPixels(WebPPicture* const pic, uint32_t color);
510
511
//------------------------------------------------------------------------------
512
513
#ifdef __cplusplus
514
}    // extern "C"
515
#endif
516
517
#endif  // WEBP_ENC_VP8I_ENC_H_