Aegisub/libaegisub/common/ycbcr_conv.cpp
2014-05-19 19:32:25 -07:00

98 lines
2.8 KiB
C++

// 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);
}
}