config.c revision a2415724fb3466168b2af5b08bd94ba732c0e753 
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@gmail.com)
11
12#include "webp/encode.h"
13
14#if defined(__cplusplus) || defined(c_plusplus)
15extern "C" {
16#endif
17
18//------------------------------------------------------------------------------
19// WebPConfig
20//------------------------------------------------------------------------------
21
22int 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
83int 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