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      1 // Copyright 2011 Google Inc. All Rights Reserved.
      2 //
      3 // This code is licensed under the same terms as WebM:
      4 //  Software License Agreement:  http://www.webmproject.org/license/software/
      5 //  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
      6 // -----------------------------------------------------------------------------
      7 //
      8 // Coding tools configuration
      9 //
     10 // Author: Skal (pascal.massimino (at) gmail.com)
     11 
     12 #include "webp/encode.h"
     13 
     14 #if defined(__cplusplus) || defined(c_plusplus)
     15 extern "C" {
     16 #endif
     17 
     18 //------------------------------------------------------------------------------
     19 // WebPConfig
     20 //------------------------------------------------------------------------------
     21 
     22 int WebPConfigInitInternal(WebPConfig* config,
     23                            WebPPreset preset, float quality, int version) {
     24   if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_ENCODER_ABI_VERSION)) {
     25     return 0;   // caller/system version mismatch!
     26   }
     27   if (config == NULL) return 0;
     28 
     29   config->quality = quality;
     30   config->target_size = 0;
     31   config->target_PSNR = 0.;
     32   config->method = 4;
     33   config->sns_strength = 50;
     34   config->filter_strength = 20;   // default: light filtering
     35   config->filter_sharpness = 0;
     36   config->filter_type = 0;        // default: simple
     37   config->partitions = 0;
     38   config->segments = 4;
     39   config->pass = 1;
     40   config->show_compressed = 0;
     41   config->preprocessing = 0;
     42   config->autofilter = 0;
     43   config->partition_limit = 0;
     44   config->alpha_compression = 1;
     45   config->alpha_filtering = 1;
     46   config->alpha_quality = 100;
     47   config->lossless = 0;
     48   config->image_hint = WEBP_HINT_DEFAULT;
     49 
     50   // TODO(skal): tune.
     51   switch (preset) {
     52     case WEBP_PRESET_PICTURE:
     53       config->sns_strength = 80;
     54       config->filter_sharpness = 4;
     55       config->filter_strength = 35;
     56       break;
     57     case WEBP_PRESET_PHOTO:
     58       config->sns_strength = 80;
     59       config->filter_sharpness = 3;
     60       config->filter_strength = 30;
     61       break;
     62     case WEBP_PRESET_DRAWING:
     63       config->sns_strength = 25;
     64       config->filter_sharpness = 6;
     65       config->filter_strength = 10;
     66       break;
     67     case WEBP_PRESET_ICON:
     68       config->sns_strength = 0;
     69       config->filter_strength = 0;   // disable filtering to retain sharpness
     70       break;
     71     case WEBP_PRESET_TEXT:
     72       config->sns_strength = 0;
     73       config->filter_strength = 0;   // disable filtering to retain sharpness
     74       config->segments = 2;
     75       break;
     76     case WEBP_PRESET_DEFAULT:
     77     default:
     78       break;
     79   }
     80   return WebPValidateConfig(config);
     81 }
     82 
     83 int WebPValidateConfig(const WebPConfig* config) {
     84   if (config == NULL) return 0;
     85   if (config->quality < 0 || config->quality > 100)
     86     return 0;
     87   if (config->target_size < 0)
     88     return 0;
     89   if (config->target_PSNR < 0)
     90     return 0;
     91   if (config->method < 0 || config->method > 6)
     92     return 0;
     93   if (config->segments < 1 || config->segments > 4)
     94     return 0;
     95   if (config->sns_strength < 0 || config->sns_strength > 100)
     96     return 0;
     97   if (config->filter_strength < 0 || config->filter_strength > 100)
     98     return 0;
     99   if (config->filter_sharpness < 0 || config->filter_sharpness > 7)
    100     return 0;
    101   if (config->filter_type < 0 || config->filter_type > 1)
    102     return 0;
    103   if (config->autofilter < 0 || config->autofilter > 1)
    104     return 0;
    105   if (config->pass < 1 || config->pass > 10)
    106     return 0;
    107   if (config->show_compressed < 0 || config->show_compressed > 1)
    108     return 0;
    109   if (config->preprocessing < 0 || config->preprocessing > 1)
    110     return 0;
    111   if (config->partitions < 0 || config->partitions > 3)
    112     return 0;
    113   if (config->partition_limit < 0 || config->partition_limit > 100)
    114     return 0;
    115   if (config->alpha_compression < 0)
    116     return 0;
    117   if (config->alpha_filtering < 0)
    118     return 0;
    119   if (config->alpha_quality < 0 || config->alpha_quality > 100)
    120     return 0;
    121   if (config->lossless < 0 || config->lossless > 1)
    122     return 0;
    123   if (config->image_hint >= WEBP_HINT_LAST)
    124     return 0;
    125   return 1;
    126 }
    127 
    128 //------------------------------------------------------------------------------
    129 
    130 #if defined(__cplusplus) || defined(c_plusplus)
    131 }    // extern "C"
    132 #endif
    133