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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: main entry point
11 //
12 // Author: Skal (pascal.massimino@gmail.com)
13 
14 #include <assert.h>
15 #include <stdlib.h>
16 #include <string.h>
17 #include <math.h>
18 
19 #include "./vp8enci.h"
20 #include "./vp8li.h"
21 #include "./cost.h"
22 #include "../utils/utils.h"
23 
24 // #define PRINT_MEMORY_INFO
25 
26 #ifdef PRINT_MEMORY_INFO
27 #include <stdio.h>
28 #endif
29 
30 //------------------------------------------------------------------------------
31 
WebPGetEncoderVersion(void)32 int WebPGetEncoderVersion(void) {
33   return (ENC_MAJ_VERSION << 16) | (ENC_MIN_VERSION << 8) | ENC_REV_VERSION;
34 }
35 
36 //------------------------------------------------------------------------------
37 // VP8Encoder
38 //------------------------------------------------------------------------------
39 
ResetSegmentHeader(VP8Encoder * const enc)40 static void ResetSegmentHeader(VP8Encoder* const enc) {
41   VP8SegmentHeader* const hdr = &enc->segment_hdr_;
42   hdr->num_segments_ = enc->config_->segments;
43   hdr->update_map_  = (hdr->num_segments_ > 1);
44   hdr->size_ = 0;
45 }
46 
ResetFilterHeader(VP8Encoder * const enc)47 static void ResetFilterHeader(VP8Encoder* const enc) {
48   VP8FilterHeader* const hdr = &enc->filter_hdr_;
49   hdr->simple_ = 1;
50   hdr->level_ = 0;
51   hdr->sharpness_ = 0;
52   hdr->i4x4_lf_delta_ = 0;
53 }
54 
ResetBoundaryPredictions(VP8Encoder * const enc)55 static void ResetBoundaryPredictions(VP8Encoder* const enc) {
56   // init boundary values once for all
57   // Note: actually, initializing the preds_[] is only needed for intra4.
58   int i;
59   uint8_t* const top = enc->preds_ - enc->preds_w_;
60   uint8_t* const left = enc->preds_ - 1;
61   for (i = -1; i < 4 * enc->mb_w_; ++i) {
62     top[i] = B_DC_PRED;
63   }
64   for (i = 0; i < 4 * enc->mb_h_; ++i) {
65     left[i * enc->preds_w_] = B_DC_PRED;
66   }
67   enc->nz_[-1] = 0;   // constant
68 }
69 
70 // Mapping from config->method_ to coding tools used.
71 //-------------------+---+---+---+---+---+---+---+
72 //   Method          | 0 | 1 | 2 | 3 |(4)| 5 | 6 |
73 //-------------------+---+---+---+---+---+---+---+
74 // fast probe        | x |   |   | x |   |   |   |
75 //-------------------+---+---+---+---+---+---+---+
76 // dynamic proba     | ~ | x | x | x | x | x | x |
77 //-------------------+---+---+---+---+---+---+---+
78 // fast mode analysis|   |   |   |   | x | x | x |
79 //-------------------+---+---+---+---+---+---+---+
80 // basic rd-opt      |   |   |   | x | x | x | x |
81 //-------------------+---+---+---+---+---+---+---+
82 // disto-score i4/16 |   |   | x |   |   |   |   |
83 //-------------------+---+---+---+---+---+---+---+
84 // rd-opt i4/16      |   |   | ~ | x | x | x | x |
85 //-------------------+---+---+---+---+---+---+---+
86 // token buffer (opt)|   |   |   | x | x | x | x |
87 //-------------------+---+---+---+---+---+---+---+
88 // Trellis           |   |   |   |   |   | x |Ful|
89 //-------------------+---+---+---+---+---+---+---+
90 // full-SNS          |   |   |   |   | x | x | x |
91 //-------------------+---+---+---+---+---+---+---+
92 
MapConfigToTools(VP8Encoder * const enc)93 static void MapConfigToTools(VP8Encoder* const enc) {
94   const WebPConfig* const config = enc->config_;
95   const int method = config->method;
96   const int limit = 100 - config->partition_limit;
97   enc->method_ = method;
98   enc->rd_opt_level_ = (method >= 6) ? RD_OPT_TRELLIS_ALL
99                      : (method >= 5) ? RD_OPT_TRELLIS
100                      : (method >= 3) ? RD_OPT_BASIC
101                      : RD_OPT_NONE;
102   enc->max_i4_header_bits_ =
103       256 * 16 * 16 *                 // upper bound: up to 16bit per 4x4 block
104       (limit * limit) / (100 * 100);  // ... modulated with a quadratic curve.
105 
106   enc->thread_level_ = config->thread_level;
107 
108   enc->do_search_ = (config->target_size > 0 || config->target_PSNR > 0);
109   if (!config->low_memory) {
110 #if !defined(DISABLE_TOKEN_BUFFER)
111     enc->use_tokens_ = (enc->rd_opt_level_ >= RD_OPT_BASIC);  // need rd stats
112 #endif
113     if (enc->use_tokens_) {
114       enc->num_parts_ = 1;   // doesn't work with multi-partition
115     }
116   }
117 }
118 
119 // Memory scaling with dimensions:
120 //  memory (bytes) ~= 2.25 * w + 0.0625 * w * h
121 //
122 // Typical memory footprint (614x440 picture)
123 //              encoder: 22111
124 //                 info: 4368
125 //                preds: 17741
126 //          top samples: 1263
127 //             non-zero: 175
128 //             lf-stats: 0
129 //                total: 45658
130 // Transient object sizes:
131 //       VP8EncIterator: 3360
132 //         VP8ModeScore: 872
133 //       VP8SegmentInfo: 732
134 //             VP8Proba: 18352
135 //              LFStats: 2048
136 // Picture size (yuv): 419328
137 
InitVP8Encoder(const WebPConfig * const config,WebPPicture * const picture)138 static VP8Encoder* InitVP8Encoder(const WebPConfig* const config,
139                                   WebPPicture* const picture) {
140   const int use_filter =
141       (config->filter_strength > 0) || (config->autofilter > 0);
142   const int mb_w = (picture->width + 15) >> 4;
143   const int mb_h = (picture->height + 15) >> 4;
144   const int preds_w = 4 * mb_w + 1;
145   const int preds_h = 4 * mb_h + 1;
146   const size_t preds_size = preds_w * preds_h * sizeof(uint8_t);
147   const int top_stride = mb_w * 16;
148   const size_t nz_size = (mb_w + 1) * sizeof(uint32_t) + ALIGN_CST;
149   const size_t info_size = mb_w * mb_h * sizeof(VP8MBInfo);
150   const size_t samples_size = 2 * top_stride * sizeof(uint8_t)  // top-luma/u/v
151                             + ALIGN_CST;                        // align all
152   const size_t lf_stats_size =
153       config->autofilter ? sizeof(LFStats) + ALIGN_CST : 0;
154   VP8Encoder* enc;
155   uint8_t* mem;
156   const uint64_t size = (uint64_t)sizeof(VP8Encoder)   // main struct
157                       + ALIGN_CST                      // cache alignment
158                       + info_size                      // modes info
159                       + preds_size                     // prediction modes
160                       + samples_size                   // top/left samples
161                       + nz_size                        // coeff context bits
162                       + lf_stats_size;                 // autofilter stats
163 
164 #ifdef PRINT_MEMORY_INFO
165   printf("===================================\n");
166   printf("Memory used:\n"
167          "             encoder: %ld\n"
168          "                info: %ld\n"
169          "               preds: %ld\n"
170          "         top samples: %ld\n"
171          "            non-zero: %ld\n"
172          "            lf-stats: %ld\n"
173          "               total: %ld\n",
174          sizeof(VP8Encoder) + ALIGN_CST, info_size,
175          preds_size, samples_size, nz_size, lf_stats_size, size);
176   printf("Transient object sizes:\n"
177          "      VP8EncIterator: %ld\n"
178          "        VP8ModeScore: %ld\n"
179          "      VP8SegmentInfo: %ld\n"
180          "            VP8Proba: %ld\n"
181          "             LFStats: %ld\n",
182          sizeof(VP8EncIterator), sizeof(VP8ModeScore),
183          sizeof(VP8SegmentInfo), sizeof(VP8Proba),
184          sizeof(LFStats));
185   printf("Picture size (yuv): %ld\n",
186          mb_w * mb_h * 384 * sizeof(uint8_t));
187   printf("===================================\n");
188 #endif
189   mem = (uint8_t*)WebPSafeMalloc(size, sizeof(*mem));
190   if (mem == NULL) {
191     WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
192     return NULL;
193   }
194   enc = (VP8Encoder*)mem;
195   mem = (uint8_t*)DO_ALIGN(mem + sizeof(*enc));
196   memset(enc, 0, sizeof(*enc));
197   enc->num_parts_ = 1 << config->partitions;
198   enc->mb_w_ = mb_w;
199   enc->mb_h_ = mb_h;
200   enc->preds_w_ = preds_w;
201   enc->mb_info_ = (VP8MBInfo*)mem;
202   mem += info_size;
203   enc->preds_ = ((uint8_t*)mem) + 1 + enc->preds_w_;
204   mem += preds_w * preds_h * sizeof(uint8_t);
205   enc->nz_ = 1 + (uint32_t*)DO_ALIGN(mem);
206   mem += nz_size;
207   enc->lf_stats_ = lf_stats_size ? (LFStats*)DO_ALIGN(mem) : NULL;
208   mem += lf_stats_size;
209 
210   // top samples (all 16-aligned)
211   mem = (uint8_t*)DO_ALIGN(mem);
212   enc->y_top_ = (uint8_t*)mem;
213   enc->uv_top_ = enc->y_top_ + top_stride;
214   mem += 2 * top_stride;
215   assert(mem <= (uint8_t*)enc + size);
216 
217   enc->config_ = config;
218   enc->profile_ = use_filter ? ((config->filter_type == 1) ? 0 : 1) : 2;
219   enc->pic_ = picture;
220   enc->percent_ = 0;
221 
222   MapConfigToTools(enc);
223   VP8EncDspInit();
224   VP8DefaultProbas(enc);
225   ResetSegmentHeader(enc);
226   ResetFilterHeader(enc);
227   ResetBoundaryPredictions(enc);
228   VP8GetResidualCostInit();
229   VP8SetResidualCoeffsInit();
230   VP8EncInitAlpha(enc);
231 
232   // lower quality means smaller output -> we modulate a little the page
233   // size based on quality. This is just a crude 1rst-order prediction.
234   {
235     const float scale = 1.f + config->quality * 5.f / 100.f;  // in [1,6]
236     VP8TBufferInit(&enc->tokens_, (int)(mb_w * mb_h * 4 * scale));
237   }
238   return enc;
239 }
240 
DeleteVP8Encoder(VP8Encoder * enc)241 static int DeleteVP8Encoder(VP8Encoder* enc) {
242   int ok = 1;
243   if (enc != NULL) {
244     ok = VP8EncDeleteAlpha(enc);
245     VP8TBufferClear(&enc->tokens_);
246     WebPSafeFree(enc);
247   }
248   return ok;
249 }
250 
251 //------------------------------------------------------------------------------
252 
GetPSNR(uint64_t err,uint64_t size)253 static double GetPSNR(uint64_t err, uint64_t size) {
254   return (err > 0 && size > 0) ? 10. * log10(255. * 255. * size / err) : 99.;
255 }
256 
FinalizePSNR(const VP8Encoder * const enc)257 static void FinalizePSNR(const VP8Encoder* const enc) {
258   WebPAuxStats* stats = enc->pic_->stats;
259   const uint64_t size = enc->sse_count_;
260   const uint64_t* const sse = enc->sse_;
261   stats->PSNR[0] = (float)GetPSNR(sse[0], size);
262   stats->PSNR[1] = (float)GetPSNR(sse[1], size / 4);
263   stats->PSNR[2] = (float)GetPSNR(sse[2], size / 4);
264   stats->PSNR[3] = (float)GetPSNR(sse[0] + sse[1] + sse[2], size * 3 / 2);
265   stats->PSNR[4] = (float)GetPSNR(sse[3], size);
266 }
267 
StoreStats(VP8Encoder * const enc)268 static void StoreStats(VP8Encoder* const enc) {
269   WebPAuxStats* const stats = enc->pic_->stats;
270   if (stats != NULL) {
271     int i, s;
272     for (i = 0; i < NUM_MB_SEGMENTS; ++i) {
273       stats->segment_level[i] = enc->dqm_[i].fstrength_;
274       stats->segment_quant[i] = enc->dqm_[i].quant_;
275       for (s = 0; s <= 2; ++s) {
276         stats->residual_bytes[s][i] = enc->residual_bytes_[s][i];
277       }
278     }
279     FinalizePSNR(enc);
280     stats->coded_size = enc->coded_size_;
281     for (i = 0; i < 3; ++i) {
282       stats->block_count[i] = enc->block_count_[i];
283     }
284   }
285   WebPReportProgress(enc->pic_, 100, &enc->percent_);  // done!
286 }
287 
WebPEncodingSetError(const WebPPicture * const pic,WebPEncodingError error)288 int WebPEncodingSetError(const WebPPicture* const pic,
289                          WebPEncodingError error) {
290   assert((int)error < VP8_ENC_ERROR_LAST);
291   assert((int)error >= VP8_ENC_OK);
292   ((WebPPicture*)pic)->error_code = error;
293   return 0;
294 }
295 
WebPReportProgress(const WebPPicture * const pic,int percent,int * const percent_store)296 int WebPReportProgress(const WebPPicture* const pic,
297                        int percent, int* const percent_store) {
298   if (percent_store != NULL && percent != *percent_store) {
299     *percent_store = percent;
300     if (pic->progress_hook && !pic->progress_hook(percent, pic)) {
301       // user abort requested
302       WebPEncodingSetError(pic, VP8_ENC_ERROR_USER_ABORT);
303       return 0;
304     }
305   }
306   return 1;  // ok
307 }
308 //------------------------------------------------------------------------------
309 
WebPEncode(const WebPConfig * config,WebPPicture * pic)310 int WebPEncode(const WebPConfig* config, WebPPicture* pic) {
311   int ok = 0;
312 
313   if (pic == NULL)
314     return 0;
315   WebPEncodingSetError(pic, VP8_ENC_OK);  // all ok so far
316   if (config == NULL)  // bad params
317     return WebPEncodingSetError(pic, VP8_ENC_ERROR_NULL_PARAMETER);
318   if (!WebPValidateConfig(config))
319     return WebPEncodingSetError(pic, VP8_ENC_ERROR_INVALID_CONFIGURATION);
320   if (pic->width <= 0 || pic->height <= 0)
321     return WebPEncodingSetError(pic, VP8_ENC_ERROR_BAD_DIMENSION);
322   if (pic->width > WEBP_MAX_DIMENSION || pic->height > WEBP_MAX_DIMENSION)
323     return WebPEncodingSetError(pic, VP8_ENC_ERROR_BAD_DIMENSION);
324 
325   if (pic->stats != NULL) memset(pic->stats, 0, sizeof(*pic->stats));
326 
327   if (!config->lossless) {
328     VP8Encoder* enc = NULL;
329     if (pic->y == NULL || pic->u == NULL || pic->v == NULL) {
330       // Make sure we have YUVA samples.
331       if (config->preprocessing & 4) {
332 #if WEBP_ENCODER_ABI_VERSION > 0x0204
333         if (!WebPPictureSmartARGBToYUVA(pic)) {
334           return 0;
335         }
336 #endif
337       } else {
338         float dithering = 0.f;
339         if (config->preprocessing & 2) {
340           const float x = config->quality / 100.f;
341           const float x2 = x * x;
342           // slowly decreasing from max dithering at low quality (q->0)
343           // to 0.5 dithering amplitude at high quality (q->100)
344           dithering = 1.0f + (0.5f - 1.0f) * x2 * x2;
345         }
346         if (!WebPPictureARGBToYUVADithered(pic, WEBP_YUV420, dithering)) {
347           return 0;
348         }
349       }
350     }
351 
352     enc = InitVP8Encoder(config, pic);
353     if (enc == NULL) return 0;  // pic->error is already set.
354     // Note: each of the tasks below account for 20% in the progress report.
355     ok = VP8EncAnalyze(enc);
356 
357     // Analysis is done, proceed to actual coding.
358     ok = ok && VP8EncStartAlpha(enc);   // possibly done in parallel
359     if (!enc->use_tokens_) {
360       ok = ok && VP8EncLoop(enc);
361     } else {
362       ok = ok && VP8EncTokenLoop(enc);
363     }
364     ok = ok && VP8EncFinishAlpha(enc);
365 
366     ok = ok && VP8EncWrite(enc);
367     StoreStats(enc);
368     if (!ok) {
369       VP8EncFreeBitWriters(enc);
370     }
371     ok &= DeleteVP8Encoder(enc);  // must always be called, even if !ok
372   } else {
373     // Make sure we have ARGB samples.
374     if (pic->argb == NULL && !WebPPictureYUVAToARGB(pic)) {
375       return 0;
376     }
377 
378     ok = VP8LEncodeImage(config, pic);  // Sets pic->error in case of problem.
379   }
380 
381   return ok;
382 }
383