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// Copyright 2011 Google Inc. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the COPYING file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
// -----------------------------------------------------------------------------
//
// Coding tools configuration
//
// Author: Skal (pascal.massimino@gmail.com)
#include "webp/encode.h"
//------------------------------------------------------------------------------
// WebPConfig
//------------------------------------------------------------------------------
int WebPConfigInitInternal(WebPConfig* config,
WebPPreset preset, float quality, int version) {
if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_ENCODER_ABI_VERSION)) {
return 0; // caller/system version mismatch!
}
if (config == NULL) return 0;
config->quality = quality;
config->target_size = 0;
config->target_PSNR = 0.;
config->method = 4;
config->sns_strength = 50;
config->filter_strength = 60; // mid-filtering
config->filter_sharpness = 0;
config->filter_type = 1; // default: strong (so U/V is filtered too)
config->partitions = 0;
config->segments = 4;
config->pass = 1;
config->show_compressed = 0;
config->preprocessing = 0;
config->autofilter = 0;
config->partition_limit = 0;
config->alpha_compression = 1;
config->alpha_filtering = 1;
config->alpha_quality = 100;
config->lossless = 0;
config->exact = 0;
config->image_hint = WEBP_HINT_DEFAULT;
config->emulate_jpeg_size = 0;
config->thread_level = 0;
config->low_memory = 0;
config->near_lossless = 100;
#ifdef WEBP_EXPERIMENTAL_FEATURES
config->delta_palettization = 0;
#endif // WEBP_EXPERIMENTAL_FEATURES
// TODO(skal): tune.
switch (preset) {
case WEBP_PRESET_PICTURE:
config->sns_strength = 80;
config->filter_sharpness = 4;
config->filter_strength = 35;
config->preprocessing &= ~2; // no dithering
break;
case WEBP_PRESET_PHOTO:
config->sns_strength = 80;
config->filter_sharpness = 3;
config->filter_strength = 30;
config->preprocessing |= 2;
break;
case WEBP_PRESET_DRAWING:
config->sns_strength = 25;
config->filter_sharpness = 6;
config->filter_strength = 10;
break;
case WEBP_PRESET_ICON:
config->sns_strength = 0;
config->filter_strength = 0; // disable filtering to retain sharpness
config->preprocessing &= ~2; // no dithering
break;
case WEBP_PRESET_TEXT:
config->sns_strength = 0;
config->filter_strength = 0; // disable filtering to retain sharpness
config->preprocessing &= ~2; // no dithering
config->segments = 2;
break;
case WEBP_PRESET_DEFAULT:
default:
break;
}
return WebPValidateConfig(config);
}
int WebPValidateConfig(const WebPConfig* config) {
if (config == NULL) return 0;
if (config->quality < 0 || config->quality > 100)
return 0;
if (config->target_size < 0)
return 0;
if (config->target_PSNR < 0)
return 0;
if (config->method < 0 || config->method > 6)
return 0;
if (config->segments < 1 || config->segments > 4)
return 0;
if (config->sns_strength < 0 || config->sns_strength > 100)
return 0;
if (config->filter_strength < 0 || config->filter_strength > 100)
return 0;
if (config->filter_sharpness < 0 || config->filter_sharpness > 7)
return 0;
if (config->filter_type < 0 || config->filter_type > 1)
return 0;
if (config->autofilter < 0 || config->autofilter > 1)
return 0;
if (config->pass < 1 || config->pass > 10)
return 0;
if (config->show_compressed < 0 || config->show_compressed > 1)
return 0;
if (config->preprocessing < 0 || config->preprocessing > 7)
return 0;
if (config->partitions < 0 || config->partitions > 3)
return 0;
if (config->partition_limit < 0 || config->partition_limit > 100)
return 0;
if (config->alpha_compression < 0)
return 0;
if (config->alpha_filtering < 0)
return 0;
if (config->alpha_quality < 0 || config->alpha_quality > 100)
return 0;
if (config->lossless < 0 || config->lossless > 1)
return 0;
if (config->near_lossless < 0 || config->near_lossless > 100)
return 0;
if (config->image_hint >= WEBP_HINT_LAST)
return 0;
if (config->emulate_jpeg_size < 0 || config->emulate_jpeg_size > 1)
return 0;
if (config->thread_level < 0 || config->thread_level > 1)
return 0;
if (config->low_memory < 0 || config->low_memory > 1)
return 0;
if (config->exact < 0 || config->exact > 1)
return 0;
#ifdef WEBP_EXPERIMENTAL_FEATURES
if (config->delta_palettization < 0 || config->delta_palettization > 1)
return 0;
#endif // WEBP_EXPERIMENTAL_FEATURES
return 1;
}
//------------------------------------------------------------------------------
#define MAX_LEVEL 9
// Mapping between -z level and -m / -q parameter settings.
static const struct {
uint8_t method_;
uint8_t quality_;
} kLosslessPresets[MAX_LEVEL + 1] = {
{ 0, 0 }, { 1, 20 }, { 2, 25 }, { 3, 30 }, { 3, 50 },
{ 4, 50 }, { 4, 75 }, { 4, 90 }, { 5, 90 }, { 6, 100 }
};
int WebPConfigLosslessPreset(WebPConfig* config, int level) {
if (config == NULL || level < 0 || level > MAX_LEVEL) return 0;
config->lossless = 1;
config->method = kLosslessPresets[level].method_;
config->quality = kLosslessPresets[level].quality_;
return 1;
}
//------------------------------------------------------------------------------
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