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LibVideo: Implement CICP color space conversion

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This adds a struct called CodingIndependentCodePoints and related enums
that are used by video codecs to define its color space that frames
must be converted from when displaying a video.

Pre-multiplied matrices and lookup tables are stored to avoid most of
the floating point division and exponentiation in the conversion.
This commit is contained in:
Zaggy1024 2022-10-10 05:03:57 -05:00 • committed by Andreas Kling
parent ba79de0439
commit cd127b65c3
15 changed files with 935 additions and 18 deletions
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65
Userland/Libraries/LibVideo/VP9/Decoder.cpp
View file

@ -7,6 +7,7 @@
#include <AK/IntegralMath.h>
#include <LibGfx/Size.h>
#include <LibVideo/Color/CodingIndependentCodePoints.h>
#include "Decoder.h"
#include "Utilities.h"
@ -149,6 +150,70 @@ bool Decoder::get_uv_subsampling_x()
return m_parser->m_subsampling_x;
}
CodingIndependentCodePoints Decoder::get_cicp_color_space()
{
ColorPrimaries color_primaries;
TransferCharacteristics transfer_characteristics;
MatrixCoefficients matrix_coefficients;
switch (m_parser->m_color_space) {
case ColorSpace::Unknown:
color_primaries = ColorPrimaries::Unspecified;
transfer_characteristics = TransferCharacteristics::Unspecified;
matrix_coefficients = MatrixCoefficients::Unspecified;
break;
case ColorSpace::Bt601:
color_primaries = ColorPrimaries::BT601;
transfer_characteristics = TransferCharacteristics::BT601;
matrix_coefficients = MatrixCoefficients::BT601;
break;
case ColorSpace::Bt709:
color_primaries = ColorPrimaries::BT709;
transfer_characteristics = TransferCharacteristics::BT709;
matrix_coefficients = MatrixCoefficients::BT709;
break;
case ColorSpace::Smpte170:
// https://www.kernel.org/doc/html/v4.9/media/uapi/v4l/pixfmt-007.html#colorspace-smpte-170m-v4l2-colorspace-smpte170m
color_primaries = ColorPrimaries::BT601;
transfer_characteristics = TransferCharacteristics::BT709;
matrix_coefficients = MatrixCoefficients::BT601;
break;
case ColorSpace::Smpte240:
color_primaries = ColorPrimaries::SMPTE240;
transfer_characteristics = TransferCharacteristics::SMPTE240;
matrix_coefficients = MatrixCoefficients::SMPTE240;
break;
case ColorSpace::Bt2020:
color_primaries = ColorPrimaries::BT2020;
// Bit depth doesn't actually matter to our transfer functions since we
// convert in floats of range 0-1 (for now?), but just for correctness set
// the TC to match the bit depth here.
if (m_parser->m_bit_depth == 12)
transfer_characteristics = TransferCharacteristics::BT2020BitDepth12;
else if (m_parser->m_bit_depth == 10)
transfer_characteristics = TransferCharacteristics::BT2020BitDepth10;
else
transfer_characteristics = TransferCharacteristics::BT709;
matrix_coefficients = MatrixCoefficients::BT2020NonConstantLuminance;
break;
case ColorSpace::RGB:
color_primaries = ColorPrimaries::BT709;
transfer_characteristics = TransferCharacteristics::Linear;
matrix_coefficients = MatrixCoefficients::Identity;
break;
case ColorSpace::Reserved:
VERIFY_NOT_REACHED();
break;
}
return { color_primaries, transfer_characteristics, matrix_coefficients, m_parser->m_color_range };
}
u8 Decoder::get_bit_depth()
{
return m_parser->m_bit_depth;
}
u8 Decoder::merge_prob(u8 pre_prob, u8 count_0, u8 count_1, u8 count_sat, u8 max_update_factor)
{
auto total_decode_count = count_0 + count_1;