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// Copyright (c) the JPEG XL Project Authors. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "lib/extras/dec/color_description.h"
#include <errno.h>
#include <cmath>
#include "lib/jxl/base/common.h"
namespace jxl {
namespace {
template <typename T>
struct EnumName {
const char* name;
T value;
};
constexpr auto kJxlColorSpaceNames =
to_array<EnumName<JxlColorSpace>>({{"RGB", JXL_COLOR_SPACE_RGB},
{"Gra", JXL_COLOR_SPACE_GRAY},
{"XYB", JXL_COLOR_SPACE_XYB},
{"CS?", JXL_COLOR_SPACE_UNKNOWN}});
constexpr auto kJxlWhitePointNames =
to_array<EnumName<JxlWhitePoint>>({{"D65", JXL_WHITE_POINT_D65},
{"Cst", JXL_WHITE_POINT_CUSTOM},
{"EER", JXL_WHITE_POINT_E},
{"DCI", JXL_WHITE_POINT_DCI}});
constexpr auto kJxlPrimariesNames =
to_array<EnumName<JxlPrimaries>>({{"SRG", JXL_PRIMARIES_SRGB},
{"Cst", JXL_PRIMARIES_CUSTOM},
{"202", JXL_PRIMARIES_2100},
{"DCI", JXL_PRIMARIES_P3}});
constexpr auto kJxlTransferFunctionNames =
to_array<EnumName<JxlTransferFunction>>(
{{"709", JXL_TRANSFER_FUNCTION_709},
{"TF?", JXL_TRANSFER_FUNCTION_UNKNOWN},
{"Lin", JXL_TRANSFER_FUNCTION_LINEAR},
{"SRG", JXL_TRANSFER_FUNCTION_SRGB},
{"PeQ", JXL_TRANSFER_FUNCTION_PQ},
{"DCI", JXL_TRANSFER_FUNCTION_DCI},
{"HLG", JXL_TRANSFER_FUNCTION_HLG},
{"", JXL_TRANSFER_FUNCTION_GAMMA}});
constexpr auto kJxlRenderingIntentNames =
to_array<EnumName<JxlRenderingIntent>>(
{{"Per", JXL_RENDERING_INTENT_PERCEPTUAL},
{"Rel", JXL_RENDERING_INTENT_RELATIVE},
{"Sat", JXL_RENDERING_INTENT_SATURATION},
{"Abs", JXL_RENDERING_INTENT_ABSOLUTE}});
template <typename T, size_t N>
Status ParseEnum(const std::string& token,
const std::array<EnumName<T>, N>& enum_values, T* value) {
for (size_t i = 0; i < enum_values.size(); i++) {
if (enum_values[i].name == token) {
*value = enum_values[i].value;
return true;
}
}
return false;
}
class Tokenizer {
public:
Tokenizer(const std::string* input, char separator)
: input_(input), separator_(separator) {}
Status Next(std::string* next) {
const size_t end = input_->find(separator_, start_);
if (end == std::string::npos) {
*next = input_->substr(start_); // rest of string
} else {
*next = input_->substr(start_, end - start_);
}
if (next->empty()) return JXL_FAILURE("Missing token");
start_ = end + 1;
return true;
}
private:
const std::string* const input_; // not owned
const char separator_;
size_t start_ = 0; // of next token
};
Status ParseDouble(const std::string& num, double* d) {
char* end;
errno = 0;
*d = strtod(num.c_str(), &end);
if (*d == 0.0 && end == num.c_str()) {
return JXL_FAILURE("Invalid double: %s", num.c_str());
}
if (std::isnan(*d)) {
return JXL_FAILURE("Invalid double: %s", num.c_str());
}
if (errno == ERANGE) {
return JXL_FAILURE("Double out of range: %s", num.c_str());
}
return true;
}
Status ParseDouble(Tokenizer* tokenizer, double* d) {
std::string num;
JXL_RETURN_IF_ERROR(tokenizer->Next(&num));
return ParseDouble(num, d);
}
Status ParseColorSpace(Tokenizer* tokenizer, JxlColorEncoding* c) {
std::string str;
JXL_RETURN_IF_ERROR(tokenizer->Next(&str));
JxlColorSpace cs;
if (ParseEnum(str, kJxlColorSpaceNames, &cs)) {
c->color_space = cs;
return true;
}
return JXL_FAILURE("Unknown ColorSpace %s", str.c_str());
}
Status ParseWhitePoint(Tokenizer* tokenizer, JxlColorEncoding* c) {
if (c->color_space == JXL_COLOR_SPACE_XYB) {
// Implicit white point.
c->white_point = JXL_WHITE_POINT_D65;
return true;
}
std::string str;
JXL_RETURN_IF_ERROR(tokenizer->Next(&str));
if (ParseEnum(str, kJxlWhitePointNames, &c->white_point)) return true;
Tokenizer xy_tokenizer(&str, ';');
c->white_point = JXL_WHITE_POINT_CUSTOM;
JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->white_point_xy + 0));
JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->white_point_xy + 1));
return true;
}
Status ParsePrimaries(Tokenizer* tokenizer, JxlColorEncoding* c) {
if (c->color_space == JXL_COLOR_SPACE_GRAY ||
c->color_space == JXL_COLOR_SPACE_XYB) {
// No primaries case.
return true;
}
std::string str;
JXL_RETURN_IF_ERROR(tokenizer->Next(&str));
if (ParseEnum(str, kJxlPrimariesNames, &c->primaries)) return true;
Tokenizer xy_tokenizer(&str, ';');
JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->primaries_red_xy + 0));
JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->primaries_red_xy + 1));
JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->primaries_green_xy + 0));
JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->primaries_green_xy + 1));
JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->primaries_blue_xy + 0));
JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->primaries_blue_xy + 1));
c->primaries = JXL_PRIMARIES_CUSTOM;
return true;
}
Status ParseRenderingIntent(Tokenizer* tokenizer, JxlColorEncoding* c) {
std::string str;
JXL_RETURN_IF_ERROR(tokenizer->Next(&str));
if (ParseEnum(str, kJxlRenderingIntentNames, &c->rendering_intent))
return true;
return JXL_FAILURE("Invalid RenderingIntent %s\n", str.c_str());
}
Status ParseTransferFunction(Tokenizer* tokenizer, JxlColorEncoding* c) {
if (c->color_space == JXL_COLOR_SPACE_XYB) {
// Implicit TF.
c->transfer_function = JXL_TRANSFER_FUNCTION_GAMMA;
c->gamma = 1 / 3.;
return true;
}
std::string str;
JXL_RETURN_IF_ERROR(tokenizer->Next(&str));
if (ParseEnum(str, kJxlTransferFunctionNames, &c->transfer_function)) {
return true;
}
if (str[0] == 'g') {
JXL_RETURN_IF_ERROR(ParseDouble(str.substr(1), &c->gamma));
c->transfer_function = JXL_TRANSFER_FUNCTION_GAMMA;
return true;
}
return JXL_FAILURE("Invalid gamma %s", str.c_str());
}
} // namespace
Status ParseDescription(const std::string& description, JxlColorEncoding* c) {
*c = {};
if (description == "sRGB") {
c->color_space = JXL_COLOR_SPACE_RGB;
c->white_point = JXL_WHITE_POINT_D65;
c->primaries = JXL_PRIMARIES_SRGB;
c->transfer_function = JXL_TRANSFER_FUNCTION_SRGB;
c->rendering_intent = JXL_RENDERING_INTENT_PERCEPTUAL;
} else if (description == "DisplayP3") {
c->color_space = JXL_COLOR_SPACE_RGB;
c->white_point = JXL_WHITE_POINT_D65;
c->primaries = JXL_PRIMARIES_P3;
c->transfer_function = JXL_TRANSFER_FUNCTION_SRGB;
c->rendering_intent = JXL_RENDERING_INTENT_PERCEPTUAL;
} else if (description == "Rec2100PQ") {
c->color_space = JXL_COLOR_SPACE_RGB;
c->white_point = JXL_WHITE_POINT_D65;
c->primaries = JXL_PRIMARIES_2100;
c->transfer_function = JXL_TRANSFER_FUNCTION_PQ;
c->rendering_intent = JXL_RENDERING_INTENT_RELATIVE;
} else if (description == "Rec2100HLG") {
c->color_space = JXL_COLOR_SPACE_RGB;
c->white_point = JXL_WHITE_POINT_D65;
c->primaries = JXL_PRIMARIES_2100;
c->transfer_function = JXL_TRANSFER_FUNCTION_HLG;
c->rendering_intent = JXL_RENDERING_INTENT_RELATIVE;
} else {
Tokenizer tokenizer(&description, '_');
JXL_RETURN_IF_ERROR(ParseColorSpace(&tokenizer, c));
JXL_RETURN_IF_ERROR(ParseWhitePoint(&tokenizer, c));
JXL_RETURN_IF_ERROR(ParsePrimaries(&tokenizer, c));
JXL_RETURN_IF_ERROR(ParseRenderingIntent(&tokenizer, c));
JXL_RETURN_IF_ERROR(ParseTransferFunction(&tokenizer, c));
}
return true;
}
} // namespace jxl