[libcamera-devel] [PATCH v2 07/18] libcamera: software_isp: Add SwStats base class

Hans de Goede hdegoede at redhat.com
Sat Jan 13 15:22:07 CET 2024


Add a virtual base class for CPU based software statistics gathering
implementations.

The idea is for the implementations to offer a configure function +
functions to gather statistics on a line by line basis. This allows
CPU based software debayering to call into interlace debayering and
statistics gathering on a line by line bases while the input data
is still hot in the cache.

This base class also allows the user of an implementation to specify
a window over which to gather statistics instead of processing the
whole frame; and it allows the implementation to choose to only
process 1/2, 1/4th, etc. of the lines instead of processing all
lines (in the window) by setting y_skip_mask_ from configure().
Skipping columns is left up the line-processing functions provided
by the implementation.

Doxygen documentation by Dennis Bonke.

Co-authored-by: Dennis Bonke <admin at dennisbonke.com>
Signed-off-by: Dennis Bonke <admin at dennisbonke.com>
Co-authored-by: Andrey Konovalov <andrey.konovalov at linaro.org>
Signed-off-by: Andrey Konovalov <andrey.konovalov at linaro.org>
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
Tested-by: Bryan O'Donoghue <bryan.odonoghue at linaro.org> # sc8280xp Lenovo x13s
Tested-by: Pavel Machek <pavel at ucw.cz>
---
 include/libcamera/internal/meson.build        |   1 +
 .../internal/software_isp/meson.build         |   6 +
 .../internal/software_isp/swisp_stats.h       |  34 +++
 .../libcamera/internal/software_isp/swstats.h | 215 ++++++++++++++++++
 src/libcamera/meson.build                     |   1 +
 src/libcamera/software_isp/meson.build        |   5 +
 src/libcamera/software_isp/swstats.cpp        |  22 ++
 7 files changed, 284 insertions(+)
 create mode 100644 include/libcamera/internal/software_isp/meson.build
 create mode 100644 include/libcamera/internal/software_isp/swisp_stats.h
 create mode 100644 include/libcamera/internal/software_isp/swstats.h
 create mode 100644 src/libcamera/software_isp/meson.build
 create mode 100644 src/libcamera/software_isp/swstats.cpp

diff --git a/include/libcamera/internal/meson.build b/include/libcamera/internal/meson.build
index 1325941d..caa533c4 100644
--- a/include/libcamera/internal/meson.build
+++ b/include/libcamera/internal/meson.build
@@ -51,3 +51,4 @@ libcamera_internal_headers = files([
 ])
 
 subdir('converter')
+subdir('software_isp')
diff --git a/include/libcamera/internal/software_isp/meson.build b/include/libcamera/internal/software_isp/meson.build
new file mode 100644
index 00000000..1c43acc4
--- /dev/null
+++ b/include/libcamera/internal/software_isp/meson.build
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: CC0-1.0
+
+libcamera_internal_headers += files([
+    'swisp_stats.h',
+    'swstats.h',
+])
diff --git a/include/libcamera/internal/software_isp/swisp_stats.h b/include/libcamera/internal/software_isp/swisp_stats.h
new file mode 100644
index 00000000..07ba7d6a
--- /dev/null
+++ b/include/libcamera/internal/software_isp/swisp_stats.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2023, Linaro Ltd
+ *
+ * swisp_stats.h - Statistics data format used by the software ISP and software IPA
+ */
+
+#pragma once
+
+namespace libcamera {
+
+/**
+ * \brief Struct that holds the statistics for the Software ISP.
+ */
+struct SwIspStats {
+	/**
+	 * \brief Holds the sum of all sampled red pixels.
+	 */
+	unsigned long sumR_;
+	/**
+	 * \brief Holds the sum of all sampled green pixels.
+	 */
+	unsigned long sumG_;
+	/**
+	 * \brief Holds the sum of all sampled blue pixels.
+	 */
+	unsigned long sumB_;
+	/**
+	 * \brief A histogram of luminance values.
+	 */
+	unsigned int y_histogram[16];
+};
+
+} /* namespace libcamera */
diff --git a/include/libcamera/internal/software_isp/swstats.h b/include/libcamera/internal/software_isp/swstats.h
new file mode 100644
index 00000000..dcac7064
--- /dev/null
+++ b/include/libcamera/internal/software_isp/swstats.h
@@ -0,0 +1,215 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2023, Linaro Ltd
+ * Copyright (C) 2023, Red Hat Inc.
+ *
+ * Authors:
+ * Hans de Goede <hdegoede at redhat.com> 
+ *
+ * swstats.h - software statistics base class
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+#include <libcamera/base/log.h>
+#include <libcamera/base/signal.h>
+
+#include <libcamera/geometry.h>
+
+namespace libcamera {
+
+class PixelFormat;
+struct SharedFD;
+struct StreamConfiguration;
+
+LOG_DECLARE_CATEGORY(SwStats)
+
+/**
+ * \class SwStats
+ * \brief Base class for the software ISP statistics.
+ *
+ * Base class for the software ISP statistics.
+ */
+class SwStats
+{
+public:
+	virtual ~SwStats() = 0;
+
+	/**
+	 * \brief Gets wether the statistics object is valid.
+	 * 
+	 * \return true if it's valid, false otherwise.
+	 */
+	virtual bool isValid() const = 0;
+
+	/**
+	 * \brief Configure the statistics object for the passed in input format.
+	 * \param[in] inputCfg The input format
+	 *
+	 * \return 0 on success, a negative errno value on failure.
+	 */
+	virtual int configure(const StreamConfiguration &inputCfg) = 0;
+
+	/**
+	 * \brief Get the file descriptor for the statistics.
+	 *
+	 * \return the file descriptor
+	 */
+	virtual const SharedFD &getStatsFD() = 0;
+
+protected:
+	/**
+	 * \brief Called when there is data to get statistics from.
+	 * \param[in] src The input data
+	 */
+	typedef void (SwStats::*statsProcessFn)(const uint8_t *src[]);
+	/**
+	 * \brief Called when the statistics gathering is done or when a new frame starts.
+	 */
+	typedef void (SwStats::*statsVoidFn)();
+
+	/* Variables set by configure(), used every line */
+	/**
+	 * \brief The function called when a line is ready for statistics processing.
+	 *
+	 * Used for line 0 and 1, repeating if there isn't a 3rd and a 4th line in the bayer order.
+	 */
+	statsProcessFn stats0_;
+	/**
+	 * \brief The function called when a line is ready for statistics processing.
+	 *
+	 * Used for line 3 and 4, only needed if the bayer order has 4 different lines.
+	 */
+	statsProcessFn stats2_;
+
+	/**
+	 * \brief The memory used per pixel in bits.
+	 */
+	unsigned int bpp_;
+	/**
+	 * \brief Skip lines where this bitmask is set in y.
+	 */
+	unsigned int y_skip_mask_;
+
+	/**
+	 * \brief Statistics window, set by setWindow(), used ever line.
+	 */
+	Rectangle window_;
+
+	/**
+	 * \brief The function called at the start of a frame.
+	 */
+	statsVoidFn startFrame_;
+	/**
+	 * \brief The function called at the end of a frame.
+	 */
+	statsVoidFn finishFrame_;
+	/**
+	 * \brief The size of the bayer pattern.
+	 */
+	Size patternSize_;
+	/**
+	 * \brief The offset of x, applied to window_.x for bayer variants.
+	 *
+	 * This can either be 0 or 1.
+	 */
+	unsigned int x_shift_;
+
+public:
+	/**
+	 * \brief Get the pattern size.
+	 *
+	 * For some input-formats, e.g. Bayer data, processing is done multiple lines
+	 * and/or columns at a time. Get width and height at which the (bayer) pattern
+	 * repeats. Window values are rounded down to a multiple of this and the height
+	 * also indicates if processLine2() should be called or not.
+	 * This may only be called after a successful configure() call.
+	 *
+	 * \return the pattern size.
+	 */
+	const Size &patternSize() { return patternSize_; }
+
+	/**
+	 * \brief Specify window coordinates over which to gather statistics.
+	 * \param[in] window The window object.
+	 */
+	void setWindow(Rectangle window)
+	{
+		window_ = window;
+
+		window_.x &= ~(patternSize_.width - 1);
+		window_.x += x_shift_;
+		window_.y &= ~(patternSize_.height - 1);
+
+		/* width_ - x_shift_ to make sure the window fits */
+		window_.width -= x_shift_;
+		window_.width &= ~(patternSize_.width - 1);
+		window_.height &= ~(patternSize_.height - 1);
+	}
+
+	/**
+	 * \brief Reset state to start statistics gathering for a new frame.
+	 * 
+	 * This may only be called after a successful setWindow() call.
+	 */
+	void startFrame()
+	{
+		(this->*startFrame_)();
+	}
+
+	/**
+	 * \brief Process line 0.
+	 * \param[in] y The y coordinate.
+	 * \param[in] src The input data.
+	 *
+	 * This function processes line 0 for input formats with patternSize height == 1.
+	 * It'll process line 0 and 1 for input formats with patternSize height >= 2.
+	 * This function may only be called after a successful setWindow() call.
+	 */
+	void processLine0(unsigned int y, const uint8_t *src[])
+	{
+		if ((y & y_skip_mask_) || y < (unsigned int)window_.y ||
+		    y >= (window_.y + window_.height))
+			return;
+
+		(this->*stats0_)(src);
+	}
+
+	/**
+	 * \brief Process line 2 and 3.
+	 * \param[in] y The y coordinate.
+	 * \param[in] src The input data.
+	 *
+	 * This function processes line 2 and 3 for input formats with patternSize height == 4.
+	 * This function may only be called after a successful setWindow() call.
+	 */
+	void processLine2(unsigned int y, const uint8_t *src[])
+	{
+		if ((y & y_skip_mask_) || y < (unsigned int)window_.y ||
+		    y >= (window_.y + window_.height))
+			return;
+
+		(this->*stats2_)(src);
+	}
+
+	/**
+	 * \brief Finish statistics calculation for the current frame.
+	 * 
+	 * This may only be called after a successful setWindow() call.
+	 */
+	void finishFrame()
+	{
+		(this->*finishFrame_)();
+	}
+
+	/**
+	 * \brief Signals that the statistics are ready.
+	 *
+	 * The int parameter isn't actually used.
+	 */
+	Signal<int> statsReady;
+};
+
+} /* namespace libcamera */
diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
index 86494663..3d63e8a2 100644
--- a/src/libcamera/meson.build
+++ b/src/libcamera/meson.build
@@ -71,6 +71,7 @@ subdir('converter')
 subdir('ipa')
 subdir('pipeline')
 subdir('proxy')
+subdir('software_isp')
 
 null_dep = dependency('', required : false)
 
diff --git a/src/libcamera/software_isp/meson.build b/src/libcamera/software_isp/meson.build
new file mode 100644
index 00000000..9359075d
--- /dev/null
+++ b/src/libcamera/software_isp/meson.build
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: CC0-1.0
+
+libcamera_sources += files([
+	'swstats.cpp',
+])
diff --git a/src/libcamera/software_isp/swstats.cpp b/src/libcamera/software_isp/swstats.cpp
new file mode 100644
index 00000000..e65a7ada
--- /dev/null
+++ b/src/libcamera/software_isp/swstats.cpp
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2023, Linaro Ltd
+ * Copyright (C) 2023, Red Hat Inc.
+ *
+ * Authors:
+ * Hans de Goede <hdegoede at redhat.com> 
+ *
+ * swstats.cpp - software statistics base class
+ */
+
+#include "libcamera/internal/software_isp/swstats.h"
+
+namespace libcamera {
+
+LOG_DEFINE_CATEGORY(SwStats)
+
+SwStats::~SwStats()
+{
+}
+
+} /* namespace libcamera */
-- 
2.43.0



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