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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 (at) gmail.com)
     13 
     14 #include <assert.h>
     15 #include <stdlib.h>
     16 #include <string.h>
     17 #include <math.h>
     18 
     19 #include "./cost_enc.h"
     20 #include "./vp8i_enc.h"
     21 #include "./vp8li_enc.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 
     32 int WebPGetEncoderVersion(void) {
     33   return (ENC_MAJ_VERSION << 16) | (ENC_MIN_VERSION << 8) | ENC_REV_VERSION;
     34 }
     35 
     36 //------------------------------------------------------------------------------
     37 // VP8Encoder
     38 //------------------------------------------------------------------------------
     39 
     40 static void ResetSegmentHeader(VP8Encoder* const enc) {
     41   VP8EncSegmentHeader* 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 
     47 static void ResetFilterHeader(VP8Encoder* const enc) {
     48   VP8EncFilterHeader* 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 
     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 | x | x |
     79 //-------------------+---+---+---+---+---+---+---+
     80 // basic rd-opt      |   |   |   | x | x | x | x |
     81 //-------------------+---+---+---+---+---+---+---+
     82 // disto-refine i4/16| x | x | x |   |   |   |   |
     83 //-------------------+---+---+---+---+---+---+---+
     84 // disto-refine uv   |   | x | x |   |   |   |   |
     85 //-------------------+---+---+---+---+---+---+---+
     86 // rd-opt i4/16      |   |   | ~ | x | x | x | x |
     87 //-------------------+---+---+---+---+---+---+---+
     88 // token buffer (opt)|   |   |   | x | x | x | x |
     89 //-------------------+---+---+---+---+---+---+---+
     90 // Trellis           |   |   |   |   |   | x |Ful|
     91 //-------------------+---+---+---+---+---+---+---+
     92 // full-SNS          |   |   |   |   | x | x | x |
     93 //-------------------+---+---+---+---+---+---+---+
     94 
     95 static void MapConfigToTools(VP8Encoder* const enc) {
     96   const WebPConfig* const config = enc->config_;
     97   const int method = config->method;
     98   const int limit = 100 - config->partition_limit;
     99   enc->method_ = method;
    100   enc->rd_opt_level_ = (method >= 6) ? RD_OPT_TRELLIS_ALL
    101                      : (method >= 5) ? RD_OPT_TRELLIS
    102                      : (method >= 3) ? RD_OPT_BASIC
    103                      : RD_OPT_NONE;
    104   enc->max_i4_header_bits_ =
    105       256 * 16 * 16 *                 // upper bound: up to 16bit per 4x4 block
    106       (limit * limit) / (100 * 100);  // ... modulated with a quadratic curve.
    107 
    108   // partition0 = 512k max.
    109   enc->mb_header_limit_ =
    110       (score_t)256 * 510 * 8 * 1024 / (enc->mb_w_ * enc->mb_h_);
    111 
    112   enc->thread_level_ = config->thread_level;
    113 
    114   enc->do_search_ = (config->target_size > 0 || config->target_PSNR > 0);
    115   if (!config->low_memory) {
    116 #if !defined(DISABLE_TOKEN_BUFFER)
    117     enc->use_tokens_ = (enc->rd_opt_level_ >= RD_OPT_BASIC);  // need rd stats
    118 #endif
    119     if (enc->use_tokens_) {
    120       enc->num_parts_ = 1;   // doesn't work with multi-partition
    121     }
    122   }
    123 }
    124 
    125 // Memory scaling with dimensions:
    126 //  memory (bytes) ~= 2.25 * w + 0.0625 * w * h
    127 //
    128 // Typical memory footprint (614x440 picture)
    129 //              encoder: 22111
    130 //                 info: 4368
    131 //                preds: 17741
    132 //          top samples: 1263
    133 //             non-zero: 175
    134 //             lf-stats: 0
    135 //                total: 45658
    136 // Transient object sizes:
    137 //       VP8EncIterator: 3360
    138 //         VP8ModeScore: 872
    139 //       VP8SegmentInfo: 732
    140 //          VP8EncProba: 18352
    141 //              LFStats: 2048
    142 // Picture size (yuv): 419328
    143 
    144 static VP8Encoder* InitVP8Encoder(const WebPConfig* const config,
    145                                   WebPPicture* const picture) {
    146   VP8Encoder* enc;
    147   const int use_filter =
    148       (config->filter_strength > 0) || (config->autofilter > 0);
    149   const int mb_w = (picture->width + 15) >> 4;
    150   const int mb_h = (picture->height + 15) >> 4;
    151   const int preds_w = 4 * mb_w + 1;
    152   const int preds_h = 4 * mb_h + 1;
    153   const size_t preds_size = preds_w * preds_h * sizeof(*enc->preds_);
    154   const int top_stride = mb_w * 16;
    155   const size_t nz_size = (mb_w + 1) * sizeof(*enc->nz_) + WEBP_ALIGN_CST;
    156   const size_t info_size = mb_w * mb_h * sizeof(*enc->mb_info_);
    157   const size_t samples_size =
    158       2 * top_stride * sizeof(*enc->y_top_)  // top-luma/u/v
    159       + WEBP_ALIGN_CST;                      // align all
    160   const size_t lf_stats_size =
    161       config->autofilter ? sizeof(*enc->lf_stats_) + WEBP_ALIGN_CST : 0;
    162   uint8_t* mem;
    163   const uint64_t size = (uint64_t)sizeof(*enc)   // main struct
    164                       + WEBP_ALIGN_CST           // cache alignment
    165                       + info_size                // modes info
    166                       + preds_size               // prediction modes
    167                       + samples_size             // top/left samples
    168                       + nz_size                  // coeff context bits
    169                       + lf_stats_size;           // autofilter stats
    170 
    171 #ifdef PRINT_MEMORY_INFO
    172   printf("===================================\n");
    173   printf("Memory used:\n"
    174          "             encoder: %ld\n"
    175          "                info: %ld\n"
    176          "               preds: %ld\n"
    177          "         top samples: %ld\n"
    178          "            non-zero: %ld\n"
    179          "            lf-stats: %ld\n"
    180          "               total: %ld\n",
    181          sizeof(*enc) + WEBP_ALIGN_CST, info_size,
    182          preds_size, samples_size, nz_size, lf_stats_size, size);
    183   printf("Transient object sizes:\n"
    184          "      VP8EncIterator: %ld\n"
    185          "        VP8ModeScore: %ld\n"
    186          "      VP8SegmentInfo: %ld\n"
    187          "         VP8EncProba: %ld\n"
    188          "             LFStats: %ld\n",
    189          sizeof(VP8EncIterator), sizeof(VP8ModeScore),
    190          sizeof(VP8SegmentInfo), sizeof(VP8EncProba),
    191          sizeof(LFStats));
    192   printf("Picture size (yuv): %ld\n",
    193          mb_w * mb_h * 384 * sizeof(uint8_t));
    194   printf("===================================\n");
    195 #endif
    196   mem = (uint8_t*)WebPSafeMalloc(size, sizeof(*mem));
    197   if (mem == NULL) {
    198     WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
    199     return NULL;
    200   }
    201   enc = (VP8Encoder*)mem;
    202   mem = (uint8_t*)WEBP_ALIGN(mem + sizeof(*enc));
    203   memset(enc, 0, sizeof(*enc));
    204   enc->num_parts_ = 1 << config->partitions;
    205   enc->mb_w_ = mb_w;
    206   enc->mb_h_ = mb_h;
    207   enc->preds_w_ = preds_w;
    208   enc->mb_info_ = (VP8MBInfo*)mem;
    209   mem += info_size;
    210   enc->preds_ = ((uint8_t*)mem) + 1 + enc->preds_w_;
    211   mem += preds_size;
    212   enc->nz_ = 1 + (uint32_t*)WEBP_ALIGN(mem);
    213   mem += nz_size;
    214   enc->lf_stats_ = lf_stats_size ? (LFStats*)WEBP_ALIGN(mem) : NULL;
    215   mem += lf_stats_size;
    216 
    217   // top samples (all 16-aligned)
    218   mem = (uint8_t*)WEBP_ALIGN(mem);
    219   enc->y_top_ = (uint8_t*)mem;
    220   enc->uv_top_ = enc->y_top_ + top_stride;
    221   mem += 2 * top_stride;
    222   assert(mem <= (uint8_t*)enc + size);
    223 
    224   enc->config_ = config;
    225   enc->profile_ = use_filter ? ((config->filter_type == 1) ? 0 : 1) : 2;
    226   enc->pic_ = picture;
    227   enc->percent_ = 0;
    228 
    229   MapConfigToTools(enc);
    230   VP8EncDspInit();
    231   VP8DefaultProbas(enc);
    232   ResetSegmentHeader(enc);
    233   ResetFilterHeader(enc);
    234   ResetBoundaryPredictions(enc);
    235   VP8EncDspCostInit();
    236   VP8EncInitAlpha(enc);
    237 
    238   // lower quality means smaller output -> we modulate a little the page
    239   // size based on quality. This is just a crude 1rst-order prediction.
    240   {
    241     const float scale = 1.f + config->quality * 5.f / 100.f;  // in [1,6]
    242     VP8TBufferInit(&enc->tokens_, (int)(mb_w * mb_h * 4 * scale));
    243   }
    244   return enc;
    245 }
    246 
    247 static int DeleteVP8Encoder(VP8Encoder* enc) {
    248   int ok = 1;
    249   if (enc != NULL) {
    250     ok = VP8EncDeleteAlpha(enc);
    251     VP8TBufferClear(&enc->tokens_);
    252     WebPSafeFree(enc);
    253   }
    254   return ok;
    255 }
    256 
    257 //------------------------------------------------------------------------------
    258 
    259 static double GetPSNR(uint64_t err, uint64_t size) {
    260   return (err > 0 && size > 0) ? 10. * log10(255. * 255. * size / err) : 99.;
    261 }
    262 
    263 static void FinalizePSNR(const VP8Encoder* const enc) {
    264   WebPAuxStats* stats = enc->pic_->stats;
    265   const uint64_t size = enc->sse_count_;
    266   const uint64_t* const sse = enc->sse_;
    267   stats->PSNR[0] = (float)GetPSNR(sse[0], size);
    268   stats->PSNR[1] = (float)GetPSNR(sse[1], size / 4);
    269   stats->PSNR[2] = (float)GetPSNR(sse[2], size / 4);
    270   stats->PSNR[3] = (float)GetPSNR(sse[0] + sse[1] + sse[2], size * 3 / 2);
    271   stats->PSNR[4] = (float)GetPSNR(sse[3], size);
    272 }
    273 
    274 static void StoreStats(VP8Encoder* const enc) {
    275   WebPAuxStats* const stats = enc->pic_->stats;
    276   if (stats != NULL) {
    277     int i, s;
    278     for (i = 0; i < NUM_MB_SEGMENTS; ++i) {
    279       stats->segment_level[i] = enc->dqm_[i].fstrength_;
    280       stats->segment_quant[i] = enc->dqm_[i].quant_;
    281       for (s = 0; s <= 2; ++s) {
    282         stats->residual_bytes[s][i] = enc->residual_bytes_[s][i];
    283       }
    284     }
    285     FinalizePSNR(enc);
    286     stats->coded_size = enc->coded_size_;
    287     for (i = 0; i < 3; ++i) {
    288       stats->block_count[i] = enc->block_count_[i];
    289     }
    290   }
    291   WebPReportProgress(enc->pic_, 100, &enc->percent_);  // done!
    292 }
    293 
    294 int WebPEncodingSetError(const WebPPicture* const pic,
    295                          WebPEncodingError error) {
    296   assert((int)error < VP8_ENC_ERROR_LAST);
    297   assert((int)error >= VP8_ENC_OK);
    298   ((WebPPicture*)pic)->error_code = error;
    299   return 0;
    300 }
    301 
    302 int WebPReportProgress(const WebPPicture* const pic,
    303                        int percent, int* const percent_store) {
    304   if (percent_store != NULL && percent != *percent_store) {
    305     *percent_store = percent;
    306     if (pic->progress_hook && !pic->progress_hook(percent, pic)) {
    307       // user abort requested
    308       WebPEncodingSetError(pic, VP8_ENC_ERROR_USER_ABORT);
    309       return 0;
    310     }
    311   }
    312   return 1;  // ok
    313 }
    314 //------------------------------------------------------------------------------
    315 
    316 int WebPEncode(const WebPConfig* config, WebPPicture* pic) {
    317   int ok = 0;
    318   if (pic == NULL) return 0;
    319 
    320   WebPEncodingSetError(pic, VP8_ENC_OK);  // all ok so far
    321   if (config == NULL) {  // bad params
    322     return WebPEncodingSetError(pic, VP8_ENC_ERROR_NULL_PARAMETER);
    323   }
    324   if (!WebPValidateConfig(config)) {
    325     return WebPEncodingSetError(pic, VP8_ENC_ERROR_INVALID_CONFIGURATION);
    326   }
    327   if (pic->width <= 0 || pic->height <= 0) {
    328     return WebPEncodingSetError(pic, VP8_ENC_ERROR_BAD_DIMENSION);
    329   }
    330   if (pic->width > WEBP_MAX_DIMENSION || pic->height > WEBP_MAX_DIMENSION) {
    331     return WebPEncodingSetError(pic, VP8_ENC_ERROR_BAD_DIMENSION);
    332   }
    333 
    334   if (pic->stats != NULL) memset(pic->stats, 0, sizeof(*pic->stats));
    335 
    336   if (!config->lossless) {
    337     VP8Encoder* enc = NULL;
    338 
    339     if (!config->exact) {
    340       WebPCleanupTransparentArea(pic);
    341     }
    342 
    343     if (pic->use_argb || pic->y == NULL || pic->u == NULL || pic->v == NULL) {
    344       // Make sure we have YUVA samples.
    345       if (config->use_sharp_yuv || (config->preprocessing & 4)) {
    346         if (!WebPPictureSharpARGBToYUVA(pic)) {
    347           return 0;
    348         }
    349       } else {
    350         float dithering = 0.f;
    351         if (config->preprocessing & 2) {
    352           const float x = config->quality / 100.f;
    353           const float x2 = x * x;
    354           // slowly decreasing from max dithering at low quality (q->0)
    355           // to 0.5 dithering amplitude at high quality (q->100)
    356           dithering = 1.0f + (0.5f - 1.0f) * x2 * x2;
    357         }
    358         if (!WebPPictureARGBToYUVADithered(pic, WEBP_YUV420, dithering)) {
    359           return 0;
    360         }
    361       }
    362     }
    363 
    364     enc = InitVP8Encoder(config, pic);
    365     if (enc == NULL) return 0;  // pic->error is already set.
    366     // Note: each of the tasks below account for 20% in the progress report.
    367     ok = VP8EncAnalyze(enc);
    368 
    369     // Analysis is done, proceed to actual coding.
    370     ok = ok && VP8EncStartAlpha(enc);   // possibly done in parallel
    371     if (!enc->use_tokens_) {
    372       ok = ok && VP8EncLoop(enc);
    373     } else {
    374       ok = ok && VP8EncTokenLoop(enc);
    375     }
    376     ok = ok && VP8EncFinishAlpha(enc);
    377 
    378     ok = ok && VP8EncWrite(enc);
    379     StoreStats(enc);
    380     if (!ok) {
    381       VP8EncFreeBitWriters(enc);
    382     }
    383     ok &= DeleteVP8Encoder(enc);  // must always be called, even if !ok
    384   } else {
    385     // Make sure we have ARGB samples.
    386     if (pic->argb == NULL && !WebPPictureYUVAToARGB(pic)) {
    387       return 0;
    388     }
    389 
    390     if (!config->exact) {
    391       WebPCleanupTransparentAreaLossless(pic);
    392     }
    393 
    394     ok = VP8LEncodeImage(config, pic);  // Sets pic->error in case of problem.
    395   }
    396 
    397   return ok;
    398 }
    399