[PATCH v3 06/16] libcamera: software_isp: Add SwStatsCpu class
Milan Zamazal
mzamazal at redhat.com
Thu Feb 15 15:20:53 CET 2024
Hans de Goede <hdegoede at redhat.com> writes:
> Add a CPU based SwStats implementation for SoftwareISP / SoftIPA use.
>
> This implementation offers 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 implementation also allows specifying a window over which to gather
> statistics instead of processing the whole frame.
>
> Doxygen documentation by Dennis Bonke.
>
> Tested-by: Bryan O'Donoghue <bryan.odonoghue at linaro.org> # sc8280xp Lenovo x13s
> Tested-by: Pavel Machek <pavel at ucw.cz>
> Reviewed-by: Pavel Machek <pavel at ucw.cz>
> Co-developed-by: Andrey Konovalov <andrey.konovalov at linaro.org>
> Signed-off-by: Andrey Konovalov <andrey.konovalov at linaro.org>
> Co-developed-by: Pavel Machek <pavel at ucw.cz>
> Signed-off-by: Pavel Machek <pavel at ucw.cz>
> Co-developed-by: Dennis Bonke <admin at dennisbonke.com>
> Signed-off-by: Dennis Bonke <admin at dennisbonke.com>
> Co-developed-by: Marttico <g.martti at gmail.com>
> Signed-off-by: Marttico <g.martti at gmail.com>
> Co-developed-by: Toon Langendam <t.langendam at gmail.com>
> Signed-off-by: Toon Langendam <t.langendam at gmail.com>
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> ---
> Changes in v3:
> - Merge SwStats base-class into SwStatsCpu
> - Move swstats_cpu.h to src/libcamera/software_isp/
> - Move documentation to .cpp file and extend it
> - Rename a bunch of foo_bar symbols to fooBar
> - Change a couple of defines and hardcoded values to constexpr
> - Remove statsBayer10P in swstats_cpu.cpp, instead move the loop to
> statsBGGR10PLine0 / statsGBRG10PLine0
> - Make startFrame() and finishFrame() normal methods instead of
> using function pointers for these
> ---
> include/libcamera/internal/meson.build | 1 +
> .../internal/software_isp/meson.build | 5 +
> .../internal/software_isp/swisp_stats.h | 38 ++++
> src/libcamera/meson.build | 1 +
> src/libcamera/software_isp/meson.build | 5 +
> src/libcamera/software_isp/swstats_cpu.cpp | 208 ++++++++++++++++++
> src/libcamera/software_isp/swstats_cpu.h | 158 +++++++++++++
> 7 files changed, 416 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 src/libcamera/software_isp/meson.build
> create mode 100644 src/libcamera/software_isp/swstats_cpu.cpp
> create mode 100644 src/libcamera/software_isp/swstats_cpu.h
>
> diff --git a/include/libcamera/internal/meson.build b/include/libcamera/internal/meson.build
> index 5807dfd9..160fdc37 100644
> --- a/include/libcamera/internal/meson.build
> +++ b/include/libcamera/internal/meson.build
> @@ -50,3 +50,4 @@ 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..66c9c3fb
> --- /dev/null
> +++ b/include/libcamera/internal/software_isp/meson.build
> @@ -0,0 +1,5 @@
> +# SPDX-License-Identifier: CC0-1.0
> +
> +libcamera_internal_headers += files([
> + 'swisp_stats.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..afe42c9a
> --- /dev/null
> +++ b/include/libcamera/internal/software_isp/swisp_stats.h
> @@ -0,0 +1,38 @@
> +/* 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 Number of bins in the yHistogram.
> + */
> + static constexpr unsigned int kYHistogramSize = 16;
> + /**
> + * \brief A histogram of luminance values.
> + */
> + std::array<unsigned int, kYHistogramSize> yHistogram;
> +};
> +
> +} /* namespace libcamera */
> diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
> index 94a95ae3..91e4cc60 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..e1fb8ccc
> --- /dev/null
> +++ b/src/libcamera/software_isp/meson.build
> @@ -0,0 +1,5 @@
> +# SPDX-License-Identifier: CC0-1.0
> +
> +libcamera_sources += files([
> + 'swstats_cpu.cpp',
> +])
> diff --git a/src/libcamera/software_isp/swstats_cpu.cpp b/src/libcamera/software_isp/swstats_cpu.cpp
> new file mode 100644
> index 00000000..a3a2eb94
> --- /dev/null
> +++ b/src/libcamera/software_isp/swstats_cpu.cpp
> @@ -0,0 +1,208 @@
> +/* 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_cpu.cpp - CPU based software statistics implementation
> + */
> +
> +#include "swstats_cpu.h"
> +
> +#include <libcamera/base/log.h>
> +
> +#include <libcamera/stream.h>
> +
> +#include "libcamera/internal/bayer_format.h"
> +
> +namespace libcamera {
> +
> +/**
> + * \class SwStatsCpu
> + * \brief Class for gathering statistics on the CPU
> + *
> + * CPU based software ISP statistics implementation.
> + *
> + * This class offers a configure function + functions to gather statistics
> + * on a line by line basis. This allows CPU based software debayering to
> + * interlace debayering and statistics gathering on a line by line bases
^^^^^
basis?
> + * while the input data is still hot in the cache.
> + *
> + * It is also possible to specify a window over which to gather
> + * statistics instead of processing the whole frame.
> + */
> +
> +LOG_DEFINE_CATEGORY(SwStatsCpu)
> +
> +SwStatsCpu::SwStatsCpu()
> +{
> + sharedStats_ = SharedMemObject<SwIspStats>("softIsp_stats");
> + if (!sharedStats_.fd().isValid())
> + LOG(SwStatsCpu, Error)
> + << "Failed to create shared memory for statistics";
> +}
> +
> +static const unsigned int kRedYMul = 77; /* 0.299 * 256 */
> +static const unsigned int kGreenYMul = 150; /* 0.587 * 256 */
> +static const unsigned int kBlueYMul = 29; /* 0.114 * 256 */
> +
> +#define SWSTATS_START_LINE_STATS(pixel_t) \
> + pixel_t r, g, g2, b; \
> + unsigned int yVal; \
> + \
> + unsigned int sumR = 0; \
> + unsigned int sumG = 0; \
> + unsigned int sumB = 0;
> +
> +#define SWSTATS_ACCUMULATE_LINE_STATS(div) \
> + sumR += r; \
> + sumG += g; \
> + sumB += b; \
> + \
> + yVal = r * kRedYMul; \
> + yVal += g * kGreenYMul; \
> + yVal += b * kBlueYMul; \
> + stats_.yHistogram[yVal / (256 * SwIspStats::kYHistogramSize * (div))]++;
> +
> +#define SWSTATS_FINISH_LINE_STATS() \
> + stats_.sumR_ += sumR; \
> + stats_.sumG_ += sumG; \
> + stats_.sumB_ += sumB;
> +
> +void SwStatsCpu::statsBGGR10PLine0(const uint8_t *src[])
> +{
> + const uint8_t *src0 = src[1] + window_.x * 5 / 4;
> + const uint8_t *src1 = src[2] + window_.x * 5 / 4;
> + const int widthInBytes = window_.width * 5 / 4;
> +
> + if (swapLines_)
> + std::swap(src0, src1);
> +
> + SWSTATS_START_LINE_STATS(uint8_t)
> +
> + /* x += 5 sample every other 2x2 block */
> + for (int x = 0; x < widthInBytes; x += 5) {
> + /* BGGR */
> + b = src0[x];
> + g = src0[x + 1];
> + g2 = src1[x];
> + r = src1[x + 1];
> + g = (g + g2) / 2;
> + /* Data is already 8 bits, divide by 1 */
> + SWSTATS_ACCUMULATE_LINE_STATS(1)
> + }
> +
> + SWSTATS_FINISH_LINE_STATS()
> +}
> +
> +void SwStatsCpu::statsGBRG10PLine0(const uint8_t *src[])
> +{
> + const uint8_t *src0 = src[1] + window_.x * 5 / 4;
> + const uint8_t *src1 = src[2] + window_.x * 5 / 4;
> + const int widthInBytes = window_.width * 5 / 4;
> +
> + if (swapLines_)
> + std::swap(src0, src1);
> +
> + SWSTATS_START_LINE_STATS(uint8_t)
> +
> + /* x += 5 sample every other 2x2 block */
> + for (int x = 0; x < widthInBytes; x += 5) {
> + /* GBRG */
> + g = src0[x];
> + b = src0[x + 1];
> + r = src1[x];
> + g2 = src1[x + 1];
> + g = (g + g2) / 2;
> + /* Data is already 8 bits, divide by 1 */
> + SWSTATS_ACCUMULATE_LINE_STATS(1)
> + }
> +
> + SWSTATS_FINISH_LINE_STATS()
> +}
> +
> +/**
> + * \brief Reset state to start statistics gathering for a new frame.
> + *
> + * This may only be called after a successful setWindow() call.
> + */
> +void SwStatsCpu::startFrame(void)
> +{
> + stats_.sumR_ = 0;
> + stats_.sumB_ = 0;
> + stats_.sumG_ = 0;
> + stats_.yHistogram.fill(0);
> +}
> +
> +/**
> + * \brief Finish statistics calculation for the current frame.
> + *
> + * This may only be called after a successful setWindow() call.
> + */
> +void SwStatsCpu::finishFrame(void)
> +{
> + *sharedStats_ = stats_;
> + statsReady.emit(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
> + */
> +int SwStatsCpu::configure(const StreamConfiguration &inputCfg)
> +{
> + BayerFormat bayerFormat =
> + BayerFormat::fromPixelFormat(inputCfg.pixelFormat);
> +
> + if (bayerFormat.bitDepth == 10 &&
> + bayerFormat.packing == BayerFormat::Packing::CSI2) {
> + patternSize_.height = 2;
> + patternSize_.width = 4; /* 5 bytes per *4* pixels */
> + /* Skip every 3th and 4th line, sample every other 2x2 block */
> + ySkipMask_ = 0x02;
> + xShift_ = 0;
> +
> + switch (bayerFormat.order) {
> + case BayerFormat::BGGR:
> + case BayerFormat::GRBG:
> + stats0_ = (SwStatsCpu::statsProcessFn)&SwStatsCpu::statsBGGR10PLine0;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Isn't the type cast superfluous? (The same below.)
> + swapLines_ = bayerFormat.order == BayerFormat::GRBG;
> + return 0;
> + case BayerFormat::GBRG:
> + case BayerFormat::RGGB:
> + stats0_ = (SwStatsCpu::statsProcessFn)&SwStatsCpu::statsGBRG10PLine0;
> + swapLines_ = bayerFormat.order == BayerFormat::RGGB;
> + return 0;
> + default:
> + break;
> + }
> + }
> +
> + LOG(SwStatsCpu, Info)
> + << "Unsupported input format " << inputCfg.pixelFormat.toString();
> + return -EINVAL;
> +}
> +
> +/**
> + * \brief Specify window coordinates over which to gather statistics.
> + * \param[in] window The window object.
> + */
> +void SwStatsCpu::setWindow(Rectangle window)
> +{
> + window_ = window;
> +
> + window_.x &= ~(patternSize_.width - 1);
> + window_.x += xShift_;
> + window_.y &= ~(patternSize_.height - 1);
> +
> + /* width_ - xShift_ to make sure the window fits */
> + window_.width -= xShift_;
> + window_.width &= ~(patternSize_.width - 1);
> + window_.height &= ~(patternSize_.height - 1);
> +}
> +
> +} /* namespace libcamera */
> diff --git a/src/libcamera/software_isp/swstats_cpu.h b/src/libcamera/software_isp/swstats_cpu.h
> new file mode 100644
> index 00000000..166ebe28
> --- /dev/null
> +++ b/src/libcamera/software_isp/swstats_cpu.h
> @@ -0,0 +1,158 @@
> +/* 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_cpu.h - CPU based software statistics implementation
> + */
> +
> +#pragma once
> +
> +#include <stdint.h>
> +
> +#include <libcamera/base/signal.h>
> +
> +#include <libcamera/geometry.h>
> +
> +#include "libcamera/internal/shared_mem_object.h"
> +#include "libcamera/internal/software_isp/swisp_stats.h"
> +
> +namespace libcamera {
> +
> +class PixelFormat;
> +struct StreamConfiguration;
> +
> +class SwStatsCpu
> +{
> +public:
> + SwStatsCpu();
> + ~SwStatsCpu() = default;
> +
> + /**
> + * \brief Gets wether the statistics object is valid.
> + *
> + * \return true if it's valid, false otherwise
> + */
> + bool isValid() const { return sharedStats_.fd().isValid(); }
> +
> + /**
> + * \brief Get the file descriptor for the statistics.
> + *
> + * \return the file descriptor
> + */
> + const SharedFD &getStatsFD() { return sharedStats_.fd(); }
> +
> + /**
> + * \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_; }
> +
> + int configure(const StreamConfiguration &inputCfg);
> + void setWindow(Rectangle window);
> + void startFrame();
> + void finishFrame();
> +
> + /**
> + * \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 & ySkipMask_) || 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 & ySkipMask_) || y < (unsigned int)window_.y ||
> + y >= (window_.y + window_.height))
> + return;
> +
> + (this->*stats2_)(src);
> + }
> +
> + /**
> + * \brief Signals that the statistics are ready.
> + *
> + * The int parameter isn't actually used.
> + */
> + Signal<int> statsReady;
> +private:
> + /**
> + * \brief Called when there is data to get statistics from.
> + * \param[in] src The input data
> + *
> + * These functions take an array of (patternSize_.height + 1) src
> + * pointers each pointing to a line in the source image. The middle
> + * element of the array will point to the actual line being processed.
> + * Earlier element(s) will point to the previous line(s) and later
> + * element(s) to the next line(s).
And are there previous lines processed anywhere? If not, what happens to the
very first line, must it be always excluded by the specified window? It looks
hard to track what is what and whether we hit the right place for the given
pattern. But I don't have any bright idea how to make it clearer so I can live
with it as it is, unless somebody else has a good suggestion.
> + *
> + * See the documentation of DebayerCpu::debayerFn for more details.
> + */
> + typedef void (SwStatsCpu::*statsProcessFn)(const uint8_t *src[]);
`using' should be apparently used instead of `typedef'.
> + void statsBGGR10PLine0(const uint8_t *src[]);
> + void statsGBRG10PLine0(const uint8_t *src[]);
> +
> + /* Variables set by configure(), used every line */
> + statsProcessFn stats0_;
> + statsProcessFn stats2_;
> + bool swapLines_;
> +
> + /**
> + * \brief Skip lines where this bitmask is set in y.
> + */
> + unsigned int ySkipMask_;
> +
> + /**
> + * \brief Statistics window, set by setWindow(), used ever line.
> + */
> + Rectangle window_;
> +
> + /**
> + * \brief The size of the bayer pattern.
> + *
> + * Valid sizes are: 2x2, 4x2 or 4x4.
> + */
> + Size patternSize_;
> +
> + /**
> + * \brief The offset of x, applied to window_.x for bayer variants.
> + *
> + * This can either be 0 or 1.
> + */
> + unsigned int xShift_;
> +
> + SharedMemObject<SwIspStats> sharedStats_;
> + SwIspStats stats_;
> +};
> +
> +} /* namespace libcamera */
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