LibVideo: Implement CICP color space conversion

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.

Userland/Libraries/LibVideo/VP9/Decoder.cpp

@@ -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;

Userland/Libraries/LibVideo/VP9/Decoder.h

@@ -10,6 +10,7 @@
 #include <AK/ByteBuffer.h>
 #include <AK/Error.h>
 #include <AK/Span.h>
+#include <LibVideo/Color/CodingIndependentCodePoints.h>
 #include <LibVideo/DecoderError.h>
 
 #include "Parser.h"
@@ -32,6 +33,8 @@ public:
     Gfx::Size<size_t> get_y_plane_size();
     bool get_uv_subsampling_y();
     bool get_uv_subsampling_x();
+    CodingIndependentCodePoints get_cicp_color_space();
+    u8 get_bit_depth();
 
 private:
     typedef i32 Intermediate;

Userland/Libraries/LibVideo/VP9/Enums.h

@@ -27,11 +27,6 @@ enum ColorSpace : u8 {
     RGB = 7
 };
 
-enum ColorRange {
-    StudioSwing,
-    FullSwing
-};
-
 enum InterpolationFilter : u8 {
     EightTap = 0,
     EightTapSmooth = 1,

Userland/Libraries/LibVideo/VP9/Parser.cpp

@@ -136,8 +136,8 @@ DecoderErrorOr<FrameType> Parser::read_frame_type()
 DecoderErrorOr<ColorRange> Parser::read_color_range()
 {
     if (TRY_READ(m_bit_stream->read_bit()))
-        return FullSwing;
-    return StudioSwing;
+        return ColorRange::Full;
+    return ColorRange::Studio;
 }
 
 /* (6.2) */
@@ -273,7 +273,7 @@ DecoderErrorOr<void> Parser::color_config()
             m_subsampling_y = true;
         }
     } else {
-        m_color_range = FullSwing;
+        m_color_range = ColorRange::Full;
         if (m_profile == 1 || m_profile == 3) {
             m_subsampling_x = false;
             m_subsampling_y = false;

Userland/Libraries/LibVideo/VP9/Parser.h

@@ -12,6 +12,7 @@
 #include <AK/Span.h>
 #include <AK/Vector.h>
 #include <LibGfx/Forward.h>
+#include <LibVideo/Color/CodingIndependentCodePoints.h>
 #include <LibVideo/DecoderError.h>
 
 #include "BitStream.h"