[libcamera-devel] [PATCH v7 4/8] libcamera: Add BayerFormat type
David Plowman
david.plowman at raspberrypi.com
Fri Sep 4 12:30:38 CEST 2020
This type encodes BayerFormats in an explicit way, that makes them
easier to use than some of the other more opaque type formats. This
makes the BayerFormat useful for editing or manipulating Bayer types
more easily.
Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---
include/libcamera/internal/bayer_format.h | 60 ++++++
src/libcamera/bayer_format.cpp | 231 ++++++++++++++++++++++
src/libcamera/meson.build | 1 +
3 files changed, 292 insertions(+)
create mode 100644 include/libcamera/internal/bayer_format.h
create mode 100644 src/libcamera/bayer_format.cpp
diff --git a/include/libcamera/internal/bayer_format.h b/include/libcamera/internal/bayer_format.h
new file mode 100644
index 0000000..deeef5b
--- /dev/null
+++ b/include/libcamera/internal/bayer_format.h
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Raspberry Pi (Trading) Ltd.
+ *
+ * bayer_format.h - Bayer Pixel Format
+ */
+#ifndef __LIBCAMERA_INTERNAL_BAYER_FORMAT_H__
+#define __LIBCAMERA_INTERNAL_BAYER_FORMAT_H__
+
+#include <stdint.h>
+#include <string>
+
+#include "libcamera/internal/v4l2_pixelformat.h"
+
+namespace libcamera {
+
+enum class Transform;
+
+class BayerFormat
+{
+public:
+ enum Order : uint8_t {
+ BGGR = 0,
+ GBRG = 1,
+ GRBG = 2,
+ RGGB = 3
+ };
+
+ enum Modifier : uint16_t {
+ None = 0,
+ Packed = 1,
+ };
+
+ constexpr BayerFormat()
+ : order(Order::BGGR), bitDepth(0), modifiers(Modifier::None)
+ {
+ }
+
+ constexpr BayerFormat(Order o, uint8_t b, Modifier m)
+ : order(o), bitDepth(b), modifiers(m)
+ {
+ }
+
+ explicit BayerFormat(V4L2PixelFormat v4l2Format);
+ bool isValid() const { return bitDepth != 0; }
+
+ std::string toString() const;
+
+ V4L2PixelFormat toV4L2PixelFormat() const;
+ BayerFormat transform(Transform t) const;
+
+ Order order;
+ uint8_t bitDepth;
+
+ Modifier modifiers;
+};
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_INTERNAL_BAYER_FORMAT_H__ */
diff --git a/src/libcamera/bayer_format.cpp b/src/libcamera/bayer_format.cpp
new file mode 100644
index 0000000..3780d7d
--- /dev/null
+++ b/src/libcamera/bayer_format.cpp
@@ -0,0 +1,231 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Raspberry Pi (Trading) Limited
+ *
+ * bayer_format.cpp - class to represent Bayer formats
+ */
+
+#include "libcamera/internal/bayer_format.h"
+
+#include <map>
+
+#include <libcamera/transform.h>
+
+/**
+ * \file bayer_format.h
+ * \brief Class to represent Bayer formats and manipulate them
+ */
+
+namespace libcamera {
+
+/**
+ * \class BayerFormat
+ * \brief Class to represent a raw image Bayer format
+ *
+ * This class encodes the different Bayer formats in such a way that they can
+ * be easily manipulated. For example, the bit depth or Bayer order can be
+ * easily altered - the Bayer order can even be "transformed" in the same
+ * manner as happens in many sensors when their horizontal or vertical "flip"
+ * controls are set.
+ */
+
+/**
+ * \enum BayerFormat::Order
+ * \brief The order of the colour channels in the Bayer pattern
+ *
+ * \var BayerFormat::BGGR
+ * \brief B then G on the first row, G then R on the second row.
+ * \var BayerFormat::GBRG
+ * \brief G then B on the first row, R then G on the second row.
+ * \var BayerFormat::GRBG
+ * \brief G then R on the first row, B then G on the second row.
+ * \var BayerFormat::RGGB
+ * \brief T then G on the first row, G then B on the second row.
+ */
+
+/**
+ * \enum BayerFormat::Modifier
+ * \brief Modifiers that can apply to a BayerFormat
+ *
+ * \var BayerFormat::None
+ * \brief No modifiers
+ * \var BayerFormat::Packed
+ * \brief Format uses MIPI CSI-2 style packing
+ */
+
+namespace {
+
+const std::map<V4L2PixelFormat, BayerFormat> v4l2ToBayer{
+ { V4L2PixelFormat(V4L2_PIX_FMT_SBGGR8), { BayerFormat::BGGR, 8, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SGBRG8), { BayerFormat::GBRG, 8, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SGRBG8), { BayerFormat::GRBG, 8, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SRGGB8), { BayerFormat::RGGB, 8, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SBGGR10), { BayerFormat::BGGR, 10, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SGBRG10), { BayerFormat::GBRG, 10, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SGRBG10), { BayerFormat::GRBG, 10, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SRGGB10), { BayerFormat::RGGB, 10, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SBGGR10P), { BayerFormat::BGGR, 10, BayerFormat::Packed } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SGBRG10P), { BayerFormat::GBRG, 10, BayerFormat::Packed } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SGRBG10P), { BayerFormat::GRBG, 10, BayerFormat::Packed } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SRGGB10P), { BayerFormat::RGGB, 10, BayerFormat::Packed } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SBGGR12), { BayerFormat::BGGR, 12, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SGBRG12), { BayerFormat::GBRG, 12, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SGRBG12), { BayerFormat::GRBG, 12, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SRGGB12), { BayerFormat::RGGB, 12, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SBGGR12P), { BayerFormat::BGGR, 12, BayerFormat::Packed } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SGBRG12P), { BayerFormat::GBRG, 12, BayerFormat::Packed } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SGRBG12P), { BayerFormat::GRBG, 12, BayerFormat::Packed } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SRGGB12P), { BayerFormat::RGGB, 12, BayerFormat::Packed } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SBGGR16), { BayerFormat::BGGR, 16, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SGBRG16), { BayerFormat::GBRG, 16, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SGRBG16), { BayerFormat::GRBG, 16, BayerFormat::None } },
+ { V4L2PixelFormat(V4L2_PIX_FMT_SRGGB16), { BayerFormat::RGGB, 16, BayerFormat::None } },
+};
+
+/* Define a slightly arbitrary ordering so that we can use a std::map. */
+struct BayerFormatComparator {
+ bool operator()(const BayerFormat &left, const BayerFormat &right) const
+ {
+ return left.bitDepth > right.bitDepth ||
+ (left.bitDepth == right.bitDepth && left.order > right.order) ||
+ (left.bitDepth == right.bitDepth && left.order == right.order &&
+ left.modifiers > right.modifiers);
+ }
+};
+
+const std::map<BayerFormat, V4L2PixelFormat, BayerFormatComparator> bayerToV4l2{
+ { { BayerFormat::BGGR, 8, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SBGGR8) },
+ { { BayerFormat::GBRG, 8, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SGBRG8) },
+ { { BayerFormat::GRBG, 8, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SGRBG8) },
+ { { BayerFormat::RGGB, 8, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SRGGB8) },
+ { { BayerFormat::BGGR, 10, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SBGGR10) },
+ { { BayerFormat::GBRG, 10, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SGBRG10) },
+ { { BayerFormat::GRBG, 10, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SGRBG10) },
+ { { BayerFormat::RGGB, 10, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SRGGB10) },
+ { { BayerFormat::BGGR, 10, BayerFormat::Packed }, V4L2PixelFormat(V4L2_PIX_FMT_SBGGR10P) },
+ { { BayerFormat::GBRG, 10, BayerFormat::Packed }, V4L2PixelFormat(V4L2_PIX_FMT_SGBRG10P) },
+ { { BayerFormat::GRBG, 10, BayerFormat::Packed }, V4L2PixelFormat(V4L2_PIX_FMT_SGRBG10P) },
+ { { BayerFormat::RGGB, 10, BayerFormat::Packed }, V4L2PixelFormat(V4L2_PIX_FMT_SRGGB10P) },
+ { { BayerFormat::BGGR, 12, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SBGGR12) },
+ { { BayerFormat::GBRG, 12, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SGBRG12) },
+ { { BayerFormat::GRBG, 12, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SGRBG12) },
+ { { BayerFormat::RGGB, 12, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SRGGB12) },
+ { { BayerFormat::BGGR, 12, BayerFormat::Packed }, V4L2PixelFormat(V4L2_PIX_FMT_SBGGR12P) },
+ { { BayerFormat::GBRG, 12, BayerFormat::Packed }, V4L2PixelFormat(V4L2_PIX_FMT_SGBRG12P) },
+ { { BayerFormat::GRBG, 12, BayerFormat::Packed }, V4L2PixelFormat(V4L2_PIX_FMT_SGRBG12P) },
+ { { BayerFormat::RGGB, 12, BayerFormat::Packed }, V4L2PixelFormat(V4L2_PIX_FMT_SRGGB12P) },
+ { { BayerFormat::BGGR, 16, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SBGGR16) },
+ { { BayerFormat::GBRG, 16, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SGBRG16) },
+ { { BayerFormat::GRBG, 16, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SGRBG16) },
+ { { BayerFormat::RGGB, 16, BayerFormat::None }, V4L2PixelFormat(V4L2_PIX_FMT_SRGGB16) },
+};
+
+} // namespace
+
+/**
+ * \fn BayerFormat::BayerFormat()
+ * \brief Construct an empty (and invalid) BayerFormat
+ */
+
+/**
+ * \fn BayerFormat::BayerFormat(Order o, uint8_t b, Modifier m)
+ * \brief Construct a BayerFormat from explicit values
+ */
+
+/**
+ * \brief Construct a BayerFormat from a V4L2PixelFormat
+ * \param[in] v4l2Format The raw format to convert into a BayerFormat
+ */
+BayerFormat::BayerFormat(V4L2PixelFormat v4l2Format)
+{
+ const auto it = v4l2ToBayer.find(v4l2Format);
+ if (it == v4l2ToBayer.end())
+ bitDepth = 0;
+ else
+ *this = it->second;
+}
+
+/**
+ * \fn BayerFormat::isValid()
+ * \brief Return whether a BayerFormat is valid
+ */
+
+/**
+ * \brief Returns a readable string representation of the BayerFormat
+ */
+std::string BayerFormat::toString() const
+{
+ std::string result;
+
+ static const char *orderStrings[] = {
+ "BGGR",
+ "GBRG",
+ "GRBG",
+ "RGGB"
+ };
+ if (order <= RGGB)
+ result = orderStrings[order];
+ else
+ result = "unknown";
+
+ result += "-" + std::to_string(bitDepth);
+
+ if (modifiers & Packed)
+ result += "-P";
+
+ return result;
+}
+
+/**
+ * \brief Convert a BayerFormat into the corresponding V4L2PixelFormat
+ */
+V4L2PixelFormat BayerFormat::toV4L2PixelFormat() const
+{
+ const auto it = bayerToV4l2.find(*this);
+ if (it != bayerToV4l2.end())
+ return it->second;
+
+ return V4L2PixelFormat();
+}
+
+/**
+ * \brief Apply a transform to this BayerFormat.
+ * \param[in] t The transform to apply
+ *
+ * For example, performing a horizontal flip on the Bayer pattern RGGB causes
+ * the RG rows of pixels to become GR, and the GB rows become BG. So the final
+ * result in this case would be GRBG.
+ */
+BayerFormat BayerFormat::transform(Transform t) const
+{
+ BayerFormat result = *this;
+
+ /*
+ * Observe that flipping bit 0 of the Order enum performs a horizontal
+ * mirror on the Bayer pattern (e.g. RGGB goes to GRBG). Similarly,
+ * flipping bit 1 performs a vertical mirror operation on it. Hence:
+ */
+ if (!!(t & Transform::HFlip))
+ result.order = static_cast<Order>(result.order ^ 1);
+ if (!!(t & Transform::VFlip))
+ result.order = static_cast<Order>(result.order ^ 2);
+
+ return result;
+}
+
+/**
+ * \var BayerFormat::order
+ * \brief The order of the colour channels in the Bayer pattern
+ */
+
+/**
+ * \var BayerFormat::bitDepth
+ * \brief The bit depth of the samples in the Bayer pattern
+ */
+
+/**
+ * \var BayerFormat::modifiers
+ * \brief Any modifier flags applied to this BayerFormat
+ */
+
+} /* namespace libcamera */
diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
index edec55e..86c225f 100644
--- a/src/libcamera/meson.build
+++ b/src/libcamera/meson.build
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: CC0-1.0
libcamera_sources = files([
+ 'bayer_format.cpp',
'bound_method.cpp',
'buffer.cpp',
'byte_stream_buffer.cpp',
--
2.20.1
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