libcamera: Add ColorSpace class

This class represents a color space by defining its color primaries,
the transfer (gamma) function it uses, the YCbCr encoding and whether
the output is full or limited range.

Signed-off-by: David Plowman <david.plowman@raspberrypi.com>
Reviewed-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

include/libcamera/color_space.h

@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Raspberry Pi (Trading) Limited
+ *
+ * color_space.h - color space definitions
+ */
+
+#pragma once
+
+#include <optional>
+#include <string>
+
+namespace libcamera {
+
+class ColorSpace
+{
+public:
+	enum class Primaries {
+		Raw,
+		Smpte170m,
+		Rec709,
+		Rec2020,
+	};
+
+	enum class TransferFunction {
+		Linear,
+		Srgb,
+		Rec709,
+	};
+
+	enum class YcbcrEncoding {
+		None,
+		Rec601,
+		Rec709,
+		Rec2020,
+	};
+
+	enum class Range {
+		Full,
+		Limited,
+	};
+
+	constexpr ColorSpace(Primaries p, TransferFunction t, YcbcrEncoding e, Range r)
+		: primaries(p), transferFunction(t), ycbcrEncoding(e), range(r)
+	{
+	}
+
+	static const ColorSpace Raw;
+	static const ColorSpace Jpeg;
+	static const ColorSpace Srgb;
+	static const ColorSpace Smpte170m;
+	static const ColorSpace Rec709;
+	static const ColorSpace Rec2020;
+
+	Primaries primaries;
+	TransferFunction transferFunction;
+	YcbcrEncoding ycbcrEncoding;
+	Range range;
+
+	std::string toString() const;
+	static std::string toString(const std::optional<ColorSpace> &colorSpace);
+};
+
+bool operator==(const ColorSpace &lhs, const ColorSpace &rhs);
+static inline bool operator!=(const ColorSpace &lhs, const ColorSpace &rhs)
+{
+	return !(lhs == rhs);
+}
+
+} /* namespace libcamera */

include/libcamera/meson.build

@@ -5,6 +5,7 @@ libcamera_include_dir = 'libcamera' / 'libcamera'
 libcamera_public_headers = files([
     'camera.h',
     'camera_manager.h',
+    'color_space.h',
     'controls.h',
     'fence.h',
     'framebuffer.h',