Add RGB <-> YCbCr conversion stuff to libaegisub

This commit is contained in:
Thomas Goyne 2013-08-25 06:27:13 -07:00
parent 9774352a77
commit cddefd8ed9
5 changed files with 197 additions and 1 deletions

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@ -84,6 +84,7 @@
<ClInclude Include="$(SrcDir)include\libaegisub\util.h" />
<ClInclude Include="$(SrcDir)include\libaegisub\util_osx.h" />
<ClInclude Include="$(SrcDir)include\libaegisub\vfr.h" />
<ClInclude Include="$(SrcDir)include\libaegisub\ycbcr_conv.h" />
<ClInclude Include="$(SrcDir)lagi_pre.h" />
<ClInclude Include="$(SrcDir)lua\modules\lpeg.h" />
</ItemGroup>
@ -120,6 +121,7 @@
<ClCompile Include="$(SrcDir)common\thesaurus.cpp" />
<ClCompile Include="$(SrcDir)common\util.cpp" />
<ClCompile Include="$(SrcDir)common\vfr.cpp" />
<ClCompile Include="$(SrcDir)common\ycbcr_conv.cpp" />
<ClCompile Include="$(SrcDir)lua\modules.cpp" />
<ClCompile Include="$(SrcDir)lua\modules\lfs.cpp" />
<ClCompile Include="$(SrcDir)lua\modules\lpeg.c">

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@ -191,6 +191,9 @@
<ClInclude Include="$(SrcDir)include\libaegisub\lua\modules.h">
<Filter>Lua</Filter>
</ClInclude>
<ClInclude Include="$(SrcDir)include\libaegisub\ycbcr_conv.h">
<Filter>Header Files</Filter>
</ClInclude>
</ItemGroup>
<ItemGroup>
<ClCompile Include="$(SrcDir)windows\lagi_pre.cpp">
@ -322,10 +325,13 @@
<ClCompile Include="$(SrcDir)lua\modules\unicode.cpp">
<Filter>Lua\Modules</Filter>
</ClCompile>
<ClCompile Include="$(SrcDir)common\ycbcr_conv.cpp">
<Filter>Source Files\Common</Filter>
</ClCompile>
</ItemGroup>
<ItemGroup>
<None Include="$(SrcDir)include\libaegisub\charsets.def">
<Filter>Header Files</Filter>
</None>
</ItemGroup>
</Project>
</Project>

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@ -41,6 +41,7 @@ SRC += \
common/thesaurus.cpp \
common/util.cpp \
common/vfr.cpp \
common/ycbcr_conv.cpp \
lua/modules.cpp \
lua/modules/lfs.cpp \
lua/modules/lpeg.c \

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@ -0,0 +1,98 @@
// Copyright (c) 2014, Thomas Goyne <plorkyeran@aegisub.org>
//
// Permission to use, copy, modify, and distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
//
// Aegisub Project http://www.aegisub.org/
#include "libaegisub/ycbcr_conv.h"
namespace {
double matrix_coefficients[][3] = {
{.299, .587, .114}, // BT.601
{.2126, .7152, .0722}, // BT.709
{.3, .59, .11}, // FCC
{.212, .701, .087}, // SMPTE 240M
};
void row_mult(std::array<double, 9>& arr, std::array<double, 3> values) {
size_t i = 0;
for (auto v : values) {
arr[i++] *= v;
arr[i++] *= v;
arr[i++] *= v;
}
}
void col_mult(std::array<double, 9>& m, std::array<double, 3> v) {
m = {{
m[0] * v[0], m[1] * v[1], m[2] * v[2],
m[3] * v[0], m[4] * v[1], m[5] * v[2],
m[6] * v[0], m[7] * v[1], m[8] * v[2],
}};
}
}
namespace agi {
void ycbcr_converter::init_src(ycbcr_matrix src_mat, ycbcr_range src_range) {
auto coeff = matrix_coefficients[(int)src_mat];
double Kr = coeff[0];
double Kg = coeff[1];
double Kb = coeff[2];
to_ycbcr = {{
Kr, Kg, Kb,
-Kr/(1-Kb), -Kg/(1-Kb), 1,
1, -Kg/(1-Kr), -Kb/(1-Kr),
}};
if (src_range == ycbcr_range::pc) {
row_mult(to_ycbcr, {{1., .5, .5}});
shift_to = {{0, 128., 128.}};
}
else {
row_mult(to_ycbcr, {{219./255., 112./255., 112./255.}});
shift_to = {{16., 128., 128.}};
}
}
void ycbcr_converter::init_dst(ycbcr_matrix dst_mat, ycbcr_range dst_range) {
auto coeff = matrix_coefficients[(int)dst_mat];
double Kr = coeff[0];
double Kg = coeff[1];
double Kb = coeff[2];
from_ycbcr = {{
1, 0, (1-Kr),
1, -(1-Kb)*Kb/Kg, -(1-Kr)*Kr/Kg,
1, (1-Kb), 0,
}};
if (dst_range == ycbcr_range::pc) {
col_mult(from_ycbcr, {{1., 2., 2.}});
shift_from = {{0, -128., -128.}};
}
else {
col_mult(from_ycbcr, {{255./219., 255./112., 255./112.}});
shift_from = {{-16., -128., -128.}};
}
}
ycbcr_converter::ycbcr_converter(ycbcr_matrix mat, ycbcr_range range) {
init_src(mat, range);
init_dst(mat, range);
}
ycbcr_converter::ycbcr_converter(ycbcr_matrix src_mat, ycbcr_range src_range, ycbcr_matrix dst_mat, ycbcr_range dst_range) {
init_src(src_mat, src_range);
init_dst(dst_mat, dst_range);
}
}

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@ -0,0 +1,89 @@
// Copyright (c) 2014, Thomas Goyne <plorkyeran@aegisub.org>
//
// Permission to use, copy, modify, and distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
//
// Aegisub Project http://www.aegisub.org/
#include <array>
#include <cstdint>
namespace agi {
enum class ycbcr_matrix {
bt601,
bt709,
fcc,
smpte_240m
};
enum class ycbcr_range {
tv,
pc
};
/// A converter between YCbCr colorspaces and RGB
class ycbcr_converter {
std::array<double, 9> from_ycbcr;
std::array<double, 9> to_ycbcr;
std::array<double, 3> shift_from;
std::array<double, 3> shift_to;
void init_dst(ycbcr_matrix dst_mat, ycbcr_range dst_range);
void init_src(ycbcr_matrix src_mat, ycbcr_range src_range);
template<typename T>
static std::array<double, 3> prod(std::array<double, 9> m, std::array<T, 3> v) {
return {{
m[0] * v[0] + m[1] * v[1] + m[2] * v[2],
m[3] * v[0] + m[4] * v[1] + m[5] * v[2],
m[6] * v[0] + m[7] * v[1] + m[8] * v[2],
}};
}
template<typename T, typename U>
static std::array<double, 3> add(std::array<T, 3> left, std::array<U, 3> right) {
return {{left[0] + right[0], left[1] + right[1], left[2] + right[2]}};
}
static uint8_t clamp(double v) {
auto i = static_cast<int>(v);
i = i > 255 ? 255 : i;
return i < 0 ? 0 : i;
}
static std::array<uint8_t, 3> to_uint8_t(std::array<double, 3> val) {
return {{clamp(val[0] + .5), clamp(val[1] + .5), clamp(val[2] + .5)}};
}
public:
ycbcr_converter(ycbcr_matrix mat, ycbcr_range range);
ycbcr_converter(ycbcr_matrix src_mat, ycbcr_range src_range, ycbcr_matrix dst_mat, ycbcr_range dst_range);
/// Convert from rgb to dst_mat/dst_range
std::array<uint8_t, 3> rgb_to_ycbcr(std::array<uint8_t, 3> input) const {
return to_uint8_t(add(prod(to_ycbcr, input), shift_to));
}
/// Convert from src_mat/src_range to rgb
std::array<uint8_t, 3> ycbcr_to_rgb(std::array<uint8_t, 3> input) const {
return to_uint8_t(prod(from_ycbcr, add(input, shift_from)));
}
/// Convert rgb to ycbcr using src_mat and then back using dst_mat
std::array<uint8_t, 3> rgb_to_rgb(std::array<uint8_t, 3> input) const {
return to_uint8_t(prod(from_ycbcr,
add(add(prod(to_ycbcr, input), shift_to), shift_from)));
}
};
}