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
20int 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->exact = 0;
47  config->image_hint = WEBP_HINT_DEFAULT;
48  config->emulate_jpeg_size = 0;
49  config->thread_level = 0;
50  config->low_memory = 0;
51  config->near_lossless = 100;
52#ifdef WEBP_EXPERIMENTAL_FEATURES
53  config->delta_palettization = 0;
54#endif // WEBP_EXPERIMENTAL_FEATURES
55
56  // TODO(skal): tune.
57  switch (preset) {
58    case WEBP_PRESET_PICTURE:
59      config->sns_strength = 80;
60      config->filter_sharpness = 4;
61      config->filter_strength = 35;
62      config->preprocessing &= ~2;   // no dithering
63      break;
64    case WEBP_PRESET_PHOTO:
65      config->sns_strength = 80;
66      config->filter_sharpness = 3;
67      config->filter_strength = 30;
68      config->preprocessing |= 2;
69      break;
70    case WEBP_PRESET_DRAWING:
71      config->sns_strength = 25;
72      config->filter_sharpness = 6;
73      config->filter_strength = 10;
74      break;
75    case WEBP_PRESET_ICON:
76      config->sns_strength = 0;
77      config->filter_strength = 0;   // disable filtering to retain sharpness
78      config->preprocessing &= ~2;   // no dithering
79      break;
80    case WEBP_PRESET_TEXT:
81      config->sns_strength = 0;
82      config->filter_strength = 0;   // disable filtering to retain sharpness
83      config->preprocessing &= ~2;   // no dithering
84      config->segments = 2;
85      break;
86    case WEBP_PRESET_DEFAULT:
87    default:
88      break;
89  }
90  return WebPValidateConfig(config);
91}
92
93int WebPValidateConfig(const WebPConfig* config) {
94  if (config == NULL) return 0;
95  if (config->quality < 0 || config->quality > 100)
96    return 0;
97  if (config->target_size < 0)
98    return 0;
99  if (config->target_PSNR < 0)
100    return 0;
101  if (config->method < 0 || config->method > 6)
102    return 0;
103  if (config->segments < 1 || config->segments > 4)
104    return 0;
105  if (config->sns_strength < 0 || config->sns_strength > 100)
106    return 0;
107  if (config->filter_strength < 0 || config->filter_strength > 100)
108    return 0;
109  if (config->filter_sharpness < 0 || config->filter_sharpness > 7)
110    return 0;
111  if (config->filter_type < 0 || config->filter_type > 1)
112    return 0;
113  if (config->autofilter < 0 || config->autofilter > 1)
114    return 0;
115  if (config->pass < 1 || config->pass > 10)
116    return 0;
117  if (config->show_compressed < 0 || config->show_compressed > 1)
118    return 0;
119  if (config->preprocessing < 0 || config->preprocessing > 7)
120    return 0;
121  if (config->partitions < 0 || config->partitions > 3)
122    return 0;
123  if (config->partition_limit < 0 || config->partition_limit > 100)
124    return 0;
125  if (config->alpha_compression < 0)
126    return 0;
127  if (config->alpha_filtering < 0)
128    return 0;
129  if (config->alpha_quality < 0 || config->alpha_quality > 100)
130    return 0;
131  if (config->lossless < 0 || config->lossless > 1)
132    return 0;
133  if (config->near_lossless < 0 || config->near_lossless > 100)
134    return 0;
135  if (config->image_hint >= WEBP_HINT_LAST)
136    return 0;
137  if (config->emulate_jpeg_size < 0 || config->emulate_jpeg_size > 1)
138    return 0;
139  if (config->thread_level < 0 || config->thread_level > 1)
140    return 0;
141  if (config->low_memory < 0 || config->low_memory > 1)
142    return 0;
143  if (config->exact < 0 || config->exact > 1)
144    return 0;
145#ifdef WEBP_EXPERIMENTAL_FEATURES
146  if (config->delta_palettization < 0 || config->delta_palettization > 1)
147    return 0;
148#endif  // WEBP_EXPERIMENTAL_FEATURES
149  return 1;
150}
151
152//------------------------------------------------------------------------------
153
154#define MAX_LEVEL 9
155
156// Mapping between -z level and -m / -q parameter settings.
157static const struct {
158  uint8_t method_;
159  uint8_t quality_;
160} kLosslessPresets[MAX_LEVEL + 1] = {
161  { 0,  0 }, { 1, 20 }, { 2, 25 }, { 3, 30 }, { 3, 50 },
162  { 4, 50 }, { 4, 75 }, { 4, 90 }, { 5, 90 }, { 6, 100 }
163};
164
165int WebPConfigLosslessPreset(WebPConfig* config, int level) {
166  if (config == NULL || level < 0 || level > MAX_LEVEL) return 0;
167  config->lossless = 1;
168  config->method = kLosslessPresets[level].method_;
169  config->quality = kLosslessPresets[level].quality_;
170  return 1;
171}
172
173//------------------------------------------------------------------------------
174