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
WebPConfigInitInternal(WebPConfig * config,WebPPreset preset,float quality,int version)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
WebPValidateConfig(const WebPConfig * config)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
WebPConfigLosslessPreset(WebPConfig * config,int level)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 //------------------------------------------------------------------------------
167