config.c revision 466727975bcc57c0c5597bcd0747a2fe4777b303 
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@gmail.com)
11
12#include <assert.h>
13#include "webp/encode.h"
14
15#if defined(__cplusplus) || defined(c_plusplus)
16extern "C" {
17#endif
18
19//-----------------------------------------------------------------------------
20// WebPConfig
21//-----------------------------------------------------------------------------
22
23int 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
79int 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