third_party/libwebp/enc/config.c

   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@gmail.com)
  13
  14 #include "../webp/encode.h"
  15
  16 //------------------------------------------------------------------------------
  17 // WebPConfig
  18 //------------------------------------------------------------------------------
  19
  20 int WebPConfigInitInternal(WebPConfig* config,
  21                            WebPPreset preset, float quality, int version) {
  22   if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_ENCODER_ABI_VERSION)) {
  23     return 0;   // caller/system version mismatch!
  24   }
  25   if (config == NULL) return 0;
  26
  27   config->quality = quality;
  28   config->target_size = 0;
  29   config->target_PSNR = 0.;
  30   config->method = 4;
  31   config->sns_strength = 50;
  32   config->filter_strength = 60;   // mid-filtering
  33   config->filter_sharpness = 0;
  34   config->filter_type = 1;        // default: strong (so U/V is filtered too)
  35   config->partitions = 0;
  36   config->segments = 4;
  37   config->pass = 1;
  38   config->show_compressed = 0;
  39   config->preprocessing = 0;
  40   config->autofilter = 0;
  41   config->partition_limit = 0;
  42   config->alpha_compression = 1;
  43   config->alpha_filtering = 1;
  44   config->alpha_quality = 100;
  45   config->lossless = 0;
  46   config->image_hint = WEBP_HINT_DEFAULT;
  47   config->emulate_jpeg_size = 0;
  48   config->thread_level = 0;
  49   config->low_memory = 0;
  50
  51   // TODO(skal): tune.
  52   switch (preset) {
  53     case WEBP_PRESET_PICTURE:
  54       config->sns_strength = 80;
  55       config->filter_sharpness = 4;
  56       config->filter_strength = 35;
  57       config->preprocessing &= ~2;   // no dithering
  58       break;
  59     case WEBP_PRESET_PHOTO:
  60       config->sns_strength = 80;
  61       config->filter_sharpness = 3;
  62       config->filter_strength = 30;
  63       config->preprocessing |= 2;
  64       break;
  65     case WEBP_PRESET_DRAWING:
  66       config->sns_strength = 25;
  67       config->filter_sharpness = 6;
  68       config->filter_strength = 10;
  69       break;
  70     case WEBP_PRESET_ICON:
  71       config->sns_strength = 0;
  72       config->filter_strength = 0;   // disable filtering to retain sharpness
  73       config->preprocessing &= ~2;   // no dithering
  74       break;
  75     case WEBP_PRESET_TEXT:
  76       config->sns_strength = 0;
  77       config->filter_strength = 0;   // disable filtering to retain sharpness
  78       config->preprocessing &= ~2;   // no dithering
  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 WEBP_ENCODER_ABI_VERSION > 0x0204
 115   if (config->preprocessing < 0 || config->preprocessing > 7)
 116 #else
 117   if (config->preprocessing < 0 || config->preprocessing > 3)
 118 #endif
 119     return 0;
 120   if (config->partitions < 0 || config->partitions > 3)
 121     return 0;
 122   if (config->partition_limit < 0 || config->partition_limit > 100)
 123     return 0;
 124   if (config->alpha_compression < 0)
 125     return 0;
 126   if (config->alpha_filtering < 0)
 127     return 0;
 128   if (config->alpha_quality < 0 || config->alpha_quality > 100)
 129     return 0;
 130   if (config->lossless < 0 || config->lossless > 1)
 131     return 0;
 132   if (config->image_hint >= WEBP_HINT_LAST)
 133     return 0;
 134   if (config->emulate_jpeg_size < 0 || config->emulate_jpeg_size > 1)
 135     return 0;
 136   if (config->thread_level < 0 || config->thread_level > 1)
 137     return 0;
 138   if (config->low_memory < 0 || config->low_memory > 1)
 139     return 0;
 140   return 1;
 141 }
 142
 143 //------------------------------------------------------------------------------
 144
 145 #if WEBP_ENCODER_ABI_VERSION > 0x0202
 146 #define MAX_LEVEL 9
 147
 148 // Mapping between -z level and -m / -q parameter settings.
 149 static const struct {
 150   uint8_t method_;
 151   uint8_t quality_;
 152 } kLosslessPresets[MAX_LEVEL + 1] = {
 153   { 0,  0 }, { 1, 20 }, { 2, 25 }, { 3, 30 }, { 3, 50 },
 154   { 4, 50 }, { 4, 75 }, { 4, 90 }, { 5, 90 }, { 6, 100 }
 155 };
 156
 157 int WebPConfigLosslessPreset(WebPConfig* config, int level) {
 158   if (config == NULL || level < 0 || level > MAX_LEVEL) return 0;
 159   config->lossless = 1;
 160   config->method = kLosslessPresets[level].method_;
 161   config->quality = kLosslessPresets[level].quality_;
 162   return 1;
 163 }
 164 #endif
 165
 166 //------------------------------------------------------------------------------