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      1 // Copyright 2011 Google Inc.
      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 <assert.h>
     13 #include "webp/encode.h"
     14 
     15 #if defined(__cplusplus) || defined(c_plusplus)
     16 extern "C" {
     17 #endif
     18 
     19 //-----------------------------------------------------------------------------
     20 // WebPConfig
     21 //-----------------------------------------------------------------------------
     22 
     23 int WebPConfigInitInternal(WebPConfig* const config,
     24                            WebPPreset preset, float quality, int version) {
     25   if (version != WEBP_ENCODER_ABI_VERSION) {
     26     return 0;   // caller/system version mismatch!
     27   }
     28   if (config == NULL) return 0;
     29 
     30   config->quality = quality;
     31   config->target_size = 0;
     32   config->target_PSNR = 0.;
     33   config->method = 4;
     34   config->sns_strength = 50;
     35   config->filter_strength = 20;   // default: light filtering
     36   config->filter_sharpness = 0;
     37   config->filter_type = 0;        // default: simple
     38   config->partitions = 0;
     39   config->segments = 4;
     40   config->pass = 1;
     41   config->show_compressed = 0;
     42   config->preprocessing = 0;
     43   config->autofilter = 0;
     44   config->alpha_compression = 0;
     45 
     46   // TODO(skal): tune.
     47   switch (preset) {
     48     case WEBP_PRESET_PICTURE:
     49       config->sns_strength = 80;
     50       config->filter_sharpness = 4;
     51       config->filter_strength = 35;
     52       break;
     53     case WEBP_PRESET_PHOTO:
     54       config->sns_strength = 80;
     55       config->filter_sharpness = 3;
     56       config->filter_strength = 30;
     57       break;
     58     case WEBP_PRESET_DRAWING:
     59       config->sns_strength = 25;
     60       config->filter_sharpness = 6;
     61       config->filter_strength = 10;
     62       break;
     63     case WEBP_PRESET_ICON:
     64       config->sns_strength = 0;
     65       config->filter_strength = 0;   // disable filtering to retain sharpness
     66       break;
     67     case WEBP_PRESET_TEXT:
     68       config->sns_strength = 0;
     69       config->filter_strength = 0;   // disable filtering to retain sharpness
     70       config->segments = 2;
     71       break;
     72     case WEBP_PRESET_DEFAULT:
     73     default:
     74       break;
     75   }
     76   return WebPValidateConfig(config);
     77 }
     78 
     79 int WebPValidateConfig(const WebPConfig* const config) {
     80   if (config == NULL) return 0;
     81   if (config->quality < 0 || config->quality > 100)
     82     return 0;
     83   if (config->target_size < 0)
     84     return 0;
     85   if (config->target_PSNR < 0)
     86     return 0;
     87   if (config->method < 0 || config->method > 6)
     88     return 0;
     89   if (config->segments < 1 || config->segments > 4)
     90     return 0;
     91   if (config->sns_strength < 0 || config->sns_strength > 100)
     92     return 0;
     93   if (config->filter_strength < 0 || config->filter_strength > 100)
     94     return 0;
     95   if (config->filter_sharpness < 0 || config->filter_sharpness > 7)
     96     return 0;
     97   if (config->filter_type < 0 || config->filter_type > 1)
     98     return 0;
     99   if (config->autofilter < 0 || config->autofilter > 1)
    100     return 0;
    101   if (config->pass < 1 || config->pass > 10)
    102     return 0;
    103   if (config->show_compressed < 0 || config->show_compressed > 1)
    104     return 0;
    105   if (config->preprocessing < 0 || config->preprocessing > 1)
    106     return 0;
    107   if (config->partitions < 0 || config->partitions > 3)
    108     return 0;
    109   if (config->alpha_compression < 0)
    110     return 0;
    111   return 1;
    112 }
    113 
    114 //-----------------------------------------------------------------------------
    115 
    116 #if defined(__cplusplus) || defined(c_plusplus)
    117 }    // extern "C"
    118 #endif
    119