new file mode 100644
@@ -0,0 +1,69 @@
+/* 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 YcbcrEncoding {
+ Rec601,
+ Rec709,
+ Rec2020,
+ };
+
+ enum class TransferFunction {
+ Linear,
+ Srgb,
+ Rec709,
+ };
+
+ enum class Range {
+ Full,
+ Limited,
+ };
+
+ constexpr ColorSpace(Primaries p, YcbcrEncoding e, TransferFunction t, Range r)
+ : primaries(p), ycbcrEncoding(e), transferFunction(t), 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;
+ YcbcrEncoding ycbcrEncoding;
+ TransferFunction transferFunction;
+ Range range;
+
+ const std::string toString() const;
+ static const 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 */
@@ -5,6 +5,7 @@ libcamera_include_dir = 'libcamera' / 'libcamera'
libcamera_public_headers = files([
'camera.h',
'camera_manager.h',
+ 'color_space.h',
'compiler.h',
'controls.h',
'file_descriptor.h',
new file mode 100644
@@ -0,0 +1,305 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Raspberry Pi (Trading) Limited
+ *
+ * color_space.cpp - color spaces.
+ */
+
+#include <libcamera/color_space.h>
+
+#include <algorithm>
+#include <map>
+#include <sstream>
+#include <utility>
+#include <vector>
+
+/**
+ * \file color_space.h
+ * \brief Class and enums to represent color spaces
+ */
+
+namespace libcamera {
+
+/**
+ * \class ColorSpace
+ * \brief Class to describe a color space
+ *
+ * The ColorSpace class defines the color primaries, the Y'CbCr encoding,
+ * the transfer function associated with the color space, and the range
+ * (sometimes also referred to as the quantisation) of the color space.
+ *
+ * Certain combinations of these fields form well-known standard color
+ * spaces such as "JPEG" or "REC709".
+ *
+ * In the strictest sense a "color space" formally only refers to the
+ * color primaries and white point. Here, however, the ColorSpace class
+ * adopts the common broader usage that includes the transfer function,
+ * Y'CbCr encoding method and quantisation.
+ *
+ * For more information on the specific color spaces described here, please
+ * see:
+ *
+ * <a href="https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/colorspaces-details.html#col-srgb">sRGB</a>
+ * <a href="https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/colorspaces-details.html#col-jpeg">JPEG</a>
+ * <a href="https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/colorspaces-details.html#col-smpte-170m">SMPTE 170M</a>
+ * <a href="https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/colorspaces-details.html#col-rec709">Rec.709</a>
+ * <a href="https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/colorspaces-details.html#col-bt2020">Rec.2020</a>
+ */
+
+/**
+ * \enum ColorSpace::Primaries
+ * \brief The color primaries for this color space
+ *
+ * \var ColorSpace::Primaries::Raw
+ * \brief These are raw colors directly from a sensor
+ *
+ * \var ColorSpace::Primaries::Smpte170m
+ * \brief SMPTE 170M color primaries
+ *
+ * \var ColorSpace::Primaries::Rec709
+ * \brief Rec.709 color primaries
+ *
+ * \var ColorSpace::Primaries::Rec2020
+ * \brief Rec.2020 color primaries
+ */
+
+/**
+ * \enum ColorSpace::YcbcrEncoding
+ * \brief The Y'CbCr encoding
+ *
+ * \var ColorSpace::YcbcrEncoding::Rec601
+ * \brief Rec.601 Y'CbCr encoding
+ *
+ * \var ColorSpace::YcbcrEncoding::Rec709
+ * \brief Rec.709 Y'CbCr encoding
+ *
+ * \var ColorSpace::YcbcrEncoding::Rec2020
+ * \brief Rec.2020 Y'CbCr encoding
+ */
+
+/**
+ * \enum ColorSpace::TransferFunction
+ * \brief The transfer function used for this color space
+ *
+ * \var ColorSpace::TransferFunction::Linear
+ * \brief This color space uses a linear (identity) transfer function
+ *
+ * \var ColorSpace::TransferFunction::Srgb
+ * \brief sRGB transfer function
+ *
+ * \var ColorSpace::TransferFunction::Rec709
+ * \brief Rec.709 transfer function
+ */
+
+/**
+ * \enum ColorSpace::Range
+ * \brief The range (sometimes "quantisation") for this color space
+ *
+ * \var ColorSpace::Range::Full
+ * \brief This color space uses full range pixel values
+ *
+ * \var ColorSpace::Range::Limited
+ * \brief This color space uses limited range pixel values, being
+ * 16 to 235 for Y' and 16 to 240 for Cb and Cr (8 bits per sample)
+ * or 64 to 940 for Y' and 16 to 960 for Cb and Cr (10 bits)
+ */
+
+/**
+ * \fn ColorSpace::ColorSpace(Primaries p, Encoding e, TransferFunction t, Range r)
+ * \brief Construct a ColorSpace from explicit values
+ * \param[in] p The color primaries
+ * \param[in] e The Y'CbCr encoding
+ * \param[in] t The transfer function for the color space
+ * \param[in] r The range of the pixel values in this color space
+ */
+
+/**
+ * \brief Assemble and return a readable string representation of the
+ * ColorSpace
+ *
+ * If the color space matches a standard ColorSpace (such as ColorSpace::Jpeg)
+ * then the short name of the color space ("Jpeg") is returned. Otherwise
+ * the four constituent parts of the ColorSpace are assembled into a longer
+ * string.
+ *
+ * \return A string describing the ColorSpace
+ */
+const std::string ColorSpace::toString() const
+{
+ /* Print out a brief name only for standard color spaces. */
+
+ static const std::vector<std::pair<ColorSpace, const char *>> colorSpaceNames = {
+ { ColorSpace::Raw, "Raw" },
+ { ColorSpace::Jpeg, "Jpeg" },
+ { ColorSpace::Srgb, "Srgb" },
+ { ColorSpace::Smpte170m, "Smpte170m" },
+ { ColorSpace::Rec709, "Rec709" },
+ { ColorSpace::Rec2020, "Rec2020" },
+ };
+ auto it = std::find_if(colorSpaceNames.begin(), colorSpaceNames.end(),
+ [this](const auto &item) {
+ return *this == item.first;
+ });
+ if (it != colorSpaceNames.end())
+ return std::string(it->second);
+
+ /* Assemble a name made of the constituent fields. */
+
+ static const std::map<Primaries, std::string> primariesNames = {
+ { Primaries::Raw, "Raw" },
+ { Primaries::Smpte170m, "Smpte170m" },
+ { Primaries::Rec709, "Rec709" },
+ { Primaries::Rec2020, "Rec2020" },
+ };
+ static const std::map<YcbcrEncoding, std::string> encodingNames = {
+ { YcbcrEncoding::Rec601, "Rec601" },
+ { YcbcrEncoding::Rec709, "Rec709" },
+ { YcbcrEncoding::Rec2020, "Rec2020" },
+ };
+ static const std::map<TransferFunction, std::string> transferNames = {
+ { TransferFunction::Linear, "Linear" },
+ { TransferFunction::Srgb, "Srgb" },
+ { TransferFunction::Rec709, "Rec709" },
+ };
+ static const std::map<Range, std::string> rangeNames = {
+ { Range::Full, "Full" },
+ { Range::Limited, "Limited" },
+ };
+
+ auto itPrimaries = primariesNames.find(primaries);
+ std::string primariesName =
+ itPrimaries == primariesNames.end() ? "Invalid" : itPrimaries->second;
+
+ auto itEncoding = encodingNames.find(ycbcrEncoding);
+ std::string encodingName =
+ itEncoding == encodingNames.end() ? "Invalid" : itEncoding->second;
+
+ auto itTransfer = transferNames.find(transferFunction);
+ std::string transferName =
+ itTransfer == transferNames.end() ? "Invalid" : itTransfer->second;
+
+ auto itRange = rangeNames.find(range);
+ std::string rangeName =
+ itRange == rangeNames.end() ? "Invalid" : itRange->second;
+
+ std::stringstream ss;
+ ss << primariesName << "/" << encodingName << "/" << transferName << "/" << rangeName;
+
+ return ss.str();
+}
+
+/**
+ * \brief Assemble and return a readable string representation of an
+ * optional ColorSpace
+ * \return A string describing the optional ColorSpace
+ */
+const std::string ColorSpace::toString(const std::optional<ColorSpace> &colorSpace)
+{
+ if (!colorSpace)
+ return "Unknown";
+
+ return colorSpace->toString();
+}
+
+/**
+ * \var ColorSpace::primaries
+ * \brief The color primaries of this color space
+ */
+
+/**
+ * \var ColorSpace::ycbcrEncoding
+ * \brief The Y'CbCr encoding used with this color space
+ */
+
+/**
+ * \var ColorSpace::transferFunction
+ * \brief The transfer function used with this color space
+ */
+
+/**
+ * \var ColorSpace::range
+ * \brief The pixel range used with this color space
+ */
+
+/**
+ * \brief A constant representing a raw color space (from a sensor)
+ */
+const ColorSpace ColorSpace::Raw = {
+ Primaries::Raw,
+ YcbcrEncoding::Rec601,
+ TransferFunction::Linear,
+ Range::Full
+};
+
+/**
+ * \brief A constant representing the JPEG color space used for
+ * encoding JPEG images.
+ */
+const ColorSpace ColorSpace::Jpeg = {
+ Primaries::Rec709,
+ YcbcrEncoding::Rec601,
+ TransferFunction::Srgb,
+ Range::Full
+};
+
+/**
+ * \brief A constant representing the sRGB color space. This is
+ * identical to the JPEG color space except that the range Y'CbCr
+ * range is limited rather than full.
+ */
+const ColorSpace ColorSpace::Srgb = {
+ Primaries::Rec709,
+ YcbcrEncoding::Rec601,
+ TransferFunction::Srgb,
+ Range::Limited
+};
+
+/**
+ * \brief A constant representing the SMPTE170M color space
+ */
+const ColorSpace ColorSpace::Smpte170m = {
+ Primaries::Smpte170m,
+ YcbcrEncoding::Rec601,
+ TransferFunction::Rec709,
+ Range::Limited
+};
+
+/**
+ * \brief A constant representing the Rec.709 color space
+ */
+const ColorSpace ColorSpace::Rec709 = {
+ Primaries::Rec709,
+ YcbcrEncoding::Rec709,
+ TransferFunction::Rec709,
+ Range::Limited
+};
+
+/**
+ * \brief A constant representing the Rec.2020 color space
+ */
+const ColorSpace ColorSpace::Rec2020 = {
+ Primaries::Rec2020,
+ YcbcrEncoding::Rec2020,
+ TransferFunction::Rec709,
+ Range::Limited
+};
+
+/**
+ * \brief Compare color spaces for equality
+ * \return True if the two color spaces are identical, false otherwise
+ */
+bool operator==(const ColorSpace &lhs, const ColorSpace &rhs)
+{
+ return lhs.primaries == rhs.primaries &&
+ lhs.ycbcrEncoding == rhs.ycbcrEncoding &&
+ lhs.transferFunction == rhs.transferFunction &&
+ lhs.range == rhs.range;
+}
+
+/**
+ * \fn bool operator!=(const ColorSpace &lhs, const ColorSpace &rhs)
+ * \brief Compare color spaces for inequality
+ * \return True if the two color spaces are not identical, false otherwise
+ */
+
+} /* namespace libcamera */
@@ -8,6 +8,7 @@ libcamera_sources = files([
'camera_manager.cpp',
'camera_sensor.cpp',
'camera_sensor_properties.cpp',
+ 'color_space.cpp',
'controls.cpp',
'control_serializer.cpp',
'control_validator.cpp',