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// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "skia/ext/cicp.h"
namespace skia {
sk_sp<SkColorSpace> CICPGetSkColorSpace(uint8_t color_primaries,
uint8_t transfer_characteristics,
uint8_t matrix_coefficients,
uint8_t full_range_flag,
bool prefer_srgb_trfn) {
if (matrix_coefficients != 0) {
return nullptr;
}
// TODO(https://crbug.com/40229816): Implement this if needed.
if (full_range_flag != 1) {
return nullptr;
}
auto transfer_id =
static_cast<SkNamedTransferFn::CicpId>(transfer_characteristics);
if (prefer_srgb_trfn) {
switch (transfer_id) {
case SkNamedTransferFn::CicpId::kRec709:
case SkNamedTransferFn::CicpId::kRec601:
case SkNamedTransferFn::CicpId::kIEC61966_2_4:
transfer_id = SkNamedTransferFn::CicpId::kSRGB;
break;
default:
break;
};
}
auto primaries_id = static_cast<SkNamedPrimaries::CicpId>(color_primaries);
return SkColorSpace::MakeCICP(primaries_id, transfer_id);
}
bool CICPGetSkYUVColorSpace(uint8_t matrix_coefficients,
uint8_t full_range_flag,
uint8_t bits_per_color,
SkYUVColorSpace& yuv_color_space) {
// Rec. ITU-T H.273, Table 4.
switch (matrix_coefficients) {
case 0:
// The identity matrix.
if (full_range_flag) {
yuv_color_space = kIdentity_SkYUVColorSpace;
return true;
}
break;
case 1:
// Rec. ITU-R BT.709-6.
yuv_color_space = full_range_flag ? kRec709_Full_SkYUVColorSpace
: kRec709_Limited_SkYUVColorSpace;
return true;
case 5:
// Rec. ITU-R BT.470-6 System B, G (historical).
case 6:
// Rec. ITU-R BT.601-7.
yuv_color_space = full_range_flag ? kJPEG_SkYUVColorSpace
: kRec601_Limited_SkYUVColorSpace;
return true;
case 9:
// Rec. ITU-R BT.2020-2 (non-constant luminance)
case 10:
// Rec. ITU-R BT.2020-2 (constant luminance)
switch (bits_per_color) {
case 8:
yuv_color_space = full_range_flag
? kBT2020_8bit_Full_SkYUVColorSpace
: kBT2020_8bit_Limited_SkYUVColorSpace;
return true;
case 10:
yuv_color_space = full_range_flag
? kBT2020_10bit_Full_SkYUVColorSpace
: kBT2020_10bit_Limited_SkYUVColorSpace;
return true;
case 12:
yuv_color_space = full_range_flag
? kBT2020_12bit_Full_SkYUVColorSpace
: kBT2020_12bit_Limited_SkYUVColorSpace;
return true;
case 16:
yuv_color_space = full_range_flag
? kBT2020_16bit_Full_SkYUVColorSpace
: kBT2020_16bit_Limited_SkYUVColorSpace;
return true;
default:
break;
}
break;
case 2:
// Unspecified.
case 3:
// Reserved.
case 4:
// United States Federal Communications Commission.
case 7:
// SMPTE ST 240.
case 8:
// YCgCo
case 11:
// YDZDX
case 12:
// Chromaticity-derived non-constant luminance system.
case 13:
// Chromaticity-derived constant luminance system.
case 14:
// ICTCP
default:
// Reserved.
break;
}
yuv_color_space = kIdentity_SkYUVColorSpace;
return false;
}
} // namespace skia
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