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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 // Coding tools configuration
     11 //
     12 // Author: Skal (pascal.massimino (at) gmail.com)
     13 
     14 #include "../webp/encode.h"
     15 
     16 #if defined(__cplusplus) || defined(c_plusplus)
     17 extern "C" {
     18 #endif
     19 
     20 //------------------------------------------------------------------------------
     21 // WebPConfig
     22 //------------------------------------------------------------------------------
     23 
     24 int WebPConfigInitInternal(WebPConfig* config,
     25                            WebPPreset preset, float quality, int version) {
     26   if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_ENCODER_ABI_VERSION)) {
     27     return 0;   // caller/system version mismatch!
     28   }
     29   if (config == NULL) return 0;
     30 
     31   config->quality = quality;
     32   config->target_size = 0;
     33   config->target_PSNR = 0.;
     34   config->method = 4;
     35   config->sns_strength = 50;
     36   config->filter_strength = 60;   // rather high filtering, helps w/ gradients.
     37   config->filter_sharpness = 0;
     38   config->filter_type = 1;        // default: strong (so U/V is filtered too)
     39   config->partitions = 0;
     40   config->segments = 4;
     41   config->pass = 1;
     42   config->show_compressed = 0;
     43   config->preprocessing = 0;
     44   config->autofilter = 0;
     45   config->partition_limit = 0;
     46   config->alpha_compression = 1;
     47   config->alpha_filtering = 1;
     48   config->alpha_quality = 100;
     49   config->lossless = 0;
     50   config->image_hint = WEBP_HINT_DEFAULT;
     51   config->emulate_jpeg_size = 0;
     52   config->thread_level = 0;
     53   config->low_memory = 0;
     54 
     55   // TODO(skal): tune.
     56   switch (preset) {
     57     case WEBP_PRESET_PICTURE:
     58       config->sns_strength = 80;
     59       config->filter_sharpness = 4;
     60       config->filter_strength = 35;
     61       break;
     62     case WEBP_PRESET_PHOTO:
     63       config->sns_strength = 80;
     64       config->filter_sharpness = 3;
     65       config->filter_strength = 30;
     66       break;
     67     case WEBP_PRESET_DRAWING:
     68       config->sns_strength = 25;
     69       config->filter_sharpness = 6;
     70       config->filter_strength = 10;
     71       break;
     72     case WEBP_PRESET_ICON:
     73       config->sns_strength = 0;
     74       config->filter_strength = 0;   // disable filtering to retain sharpness
     75       break;
     76     case WEBP_PRESET_TEXT:
     77       config->sns_strength = 0;
     78       config->filter_strength = 0;   // disable filtering to retain sharpness
     79       config->segments = 2;
     80       break;
     81     case WEBP_PRESET_DEFAULT:
     82     default:
     83       break;
     84   }
     85   return WebPValidateConfig(config);
     86 }
     87 
     88 int WebPValidateConfig(const WebPConfig* config) {
     89   if (config == NULL) return 0;
     90   if (config->quality < 0 || config->quality > 100)
     91     return 0;
     92   if (config->target_size < 0)
     93     return 0;
     94   if (config->target_PSNR < 0)
     95     return 0;
     96   if (config->method < 0 || config->method > 6)
     97     return 0;
     98   if (config->segments < 1 || config->segments > 4)
     99     return 0;
    100   if (config->sns_strength < 0 || config->sns_strength > 100)
    101     return 0;
    102   if (config->filter_strength < 0 || config->filter_strength > 100)
    103     return 0;
    104   if (config->filter_sharpness < 0 || config->filter_sharpness > 7)
    105     return 0;
    106   if (config->filter_type < 0 || config->filter_type > 1)
    107     return 0;
    108   if (config->autofilter < 0 || config->autofilter > 1)
    109     return 0;
    110   if (config->pass < 1 || config->pass > 10)
    111     return 0;
    112   if (config->show_compressed < 0 || config->show_compressed > 1)
    113     return 0;
    114   if (config->preprocessing < 0 || config->preprocessing > 1)
    115     return 0;
    116   if (config->partitions < 0 || config->partitions > 3)
    117     return 0;
    118   if (config->partition_limit < 0 || config->partition_limit > 100)
    119     return 0;
    120   if (config->alpha_compression < 0)
    121     return 0;
    122   if (config->alpha_filtering < 0)
    123     return 0;
    124   if (config->alpha_quality < 0 || config->alpha_quality > 100)
    125     return 0;
    126   if (config->lossless < 0 || config->lossless > 1)
    127     return 0;
    128   if (config->image_hint >= WEBP_HINT_LAST)
    129     return 0;
    130   if (config->emulate_jpeg_size < 0 || config->emulate_jpeg_size > 1)
    131     return 0;
    132   if (config->thread_level < 0 || config->thread_level > 1)
    133     return 0;
    134   if (config->low_memory < 0 || config->low_memory > 1)
    135     return 0;
    136   return 1;
    137 }
    138 
    139 //------------------------------------------------------------------------------
    140 
    141 #if defined(__cplusplus) || defined(c_plusplus)
    142 }    // extern "C"
    143 #endif
    144