pipeline: ipa: raspberrypi: Refactor and move the Raspberry Pi code

Split the Raspberry Pi pipeline handler and IPA source code into common
and VC4/BCM2835 specific file structures.

For the pipeline handler, the common code files now live in
src/libcamera/pipeline/rpi/common/
and the VC4-specific files in src/libcamera/pipeline/rpi/vc4/.

For the IPA, the common code files now live in
src/ipa/rpi/{cam_helper,controller}/
and the vc4 specific files in src/ipa/rpi/vc4/. With this change, the
camera tuning files are now installed under share/libcamera/ipa/rpi/vc4/.

To build the pipeline and IPA, the meson configuration options have now
changed from "raspberrypi" to "rpi/vc4":

meson setup build -Dipas=rpi/vc4 -Dpipelines=rpi/vc4

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

13 files changed, 1920 insertions, 0 deletions

diff --git a/src/ipa/rpi/cam_helper/cam_helper.cpp b/src/ipa/rpi/cam_helper/cam_helper.cpp
new file mode 100644
index 00000000..ddd5e9a4
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/cam_helper.cpp
@@ -0,0 +1,265 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi Ltd
+ *
+ * cam_helper.cpp - helper information for different sensors
+ */
+
+#include <linux/videodev2.h>
+
+#include <limits>
+#include <map>
+#include <string.h>
+
+#include "libcamera/internal/v4l2_videodevice.h"
+
+#include "cam_helper.h"
+#include "md_parser.h"
+
+using namespace RPiController;
+using namespace libcamera;
+using libcamera::utils::Duration;
+using namespace std::literals::chrono_literals;
+
+namespace libcamera {
+LOG_DECLARE_CATEGORY(IPARPI)
+}
+
+namespace {
+
+std::map<std::string, CamHelperCreateFunc> &camHelpers()
+{
+	static std::map<std::string, CamHelperCreateFunc> helpers;
+	return helpers;
+}
+
+} /* namespace */
+
+CamHelper *CamHelper::create(std::string const &camName)
+{
+	/*
+	 * CamHelpers get registered by static RegisterCamHelper
+	 * initialisers.
+	 */
+	for (auto &p : camHelpers()) {
+		if (camName.find(p.first) != std::string::npos)
+			return p.second();
+	}
+
+	return nullptr;
+}
+
+CamHelper::CamHelper(std::unique_ptr<MdParser> parser, unsigned int frameIntegrationDiff)
+	: parser_(std::move(parser)), frameIntegrationDiff_(frameIntegrationDiff)
+{
+}
+
+CamHelper::~CamHelper()
+{
+}
+
+void CamHelper::prepare(Span<const uint8_t> buffer,
+			Metadata &metadata)
+{
+	parseEmbeddedData(buffer, metadata);
+}
+
+void CamHelper::process([[maybe_unused]] StatisticsPtr &stats,
+			[[maybe_unused]] Metadata &metadata)
+{
+}
+
+uint32_t CamHelper::exposureLines(const Duration exposure, const Duration lineLength) const
+{
+	return exposure / lineLength;
+}
+
+Duration CamHelper::exposure(uint32_t exposureLines, const Duration lineLength) const
+{
+	return exposureLines * lineLength;
+}
+
+std::pair<uint32_t, uint32_t> CamHelper::getBlanking(Duration &exposure,
+						     Duration minFrameDuration,
+						     Duration maxFrameDuration) const
+{
+	uint32_t frameLengthMin, frameLengthMax, vblank, hblank;
+	Duration lineLength = mode_.minLineLength;
+
+	/*
+	 * minFrameDuration and maxFrameDuration are clamped by the caller
+	 * based on the limits for the active sensor mode.
+	 *
+	 * frameLengthMax gets calculated on the smallest line length as we do
+	 * not want to extend that unless absolutely necessary.
+	 */
+	frameLengthMin = minFrameDuration / mode_.minLineLength;
+	frameLengthMax = maxFrameDuration / mode_.minLineLength;
+
+	/*
+	 * Watch out for (exposureLines + frameIntegrationDiff_) overflowing a
+	 * uint32_t in the std::clamp() below when the exposure time is
+	 * extremely (extremely!) long - as happens when the IPA calculates the
+	 * maximum possible exposure time.
+	 */
+	uint32_t exposureLines = std::min(CamHelper::exposureLines(exposure, lineLength),
+					  std::numeric_limits<uint32_t>::max() - frameIntegrationDiff_);
+	uint32_t frameLengthLines = std::clamp(exposureLines + frameIntegrationDiff_,
+					       frameLengthMin, frameLengthMax);
+
+	/*
+	 * If our frame length lines is above the maximum allowed, see if we can
+	 * extend the line length to accommodate the requested frame length.
+	 */
+	if (frameLengthLines > mode_.maxFrameLength) {
+		Duration lineLengthAdjusted = lineLength * frameLengthLines / mode_.maxFrameLength;
+		lineLength = std::min(mode_.maxLineLength, lineLengthAdjusted);
+		frameLengthLines = mode_.maxFrameLength;
+	}
+
+	hblank = lineLengthToHblank(lineLength);
+	vblank = frameLengthLines - mode_.height;
+
+	/*
+	 * Limit the exposure to the maximum frame duration requested, and
+	 * re-calculate if it has been clipped.
+	 */
+	exposureLines = std::min(frameLengthLines - frameIntegrationDiff_,
+				 CamHelper::exposureLines(exposure, lineLength));
+	exposure = CamHelper::exposure(exposureLines, lineLength);
+
+	return { vblank, hblank };
+}
+
+Duration CamHelper::hblankToLineLength(uint32_t hblank) const
+{
+	return (mode_.width + hblank) * (1.0s / mode_.pixelRate);
+}
+
+uint32_t CamHelper::lineLengthToHblank(const Duration &lineLength) const
+{
+	return (lineLength * mode_.pixelRate / 1.0s) - mode_.width;
+}
+
+Duration CamHelper::lineLengthPckToDuration(uint32_t lineLengthPck) const
+{
+	return lineLengthPck * (1.0s / mode_.pixelRate);
+}
+
+void CamHelper::setCameraMode(const CameraMode &mode)
+{
+	mode_ = mode;
+	if (parser_) {
+		parser_->reset();
+		parser_->setBitsPerPixel(mode.bitdepth);
+		parser_->setLineLengthBytes(0); /* We use SetBufferSize. */
+	}
+}
+
+void CamHelper::getDelays(int &exposureDelay, int &gainDelay,
+			  int &vblankDelay, int &hblankDelay) const
+{
+	/*
+	 * These values are correct for many sensors. Other sensors will
+	 * need to over-ride this function.
+	 */
+	exposureDelay = 2;
+	gainDelay = 1;
+	vblankDelay = 2;
+	hblankDelay = 2;
+}
+
+bool CamHelper::sensorEmbeddedDataPresent() const
+{
+	return false;
+}
+
+double CamHelper::getModeSensitivity([[maybe_unused]] const CameraMode &mode) const
+{
+	/*
+	 * Most sensors have the same sensitivity in every mode, but this
+	 * function can be overridden for those that do not. Note that it is
+	 * called before mode_ is set, so it must return the sensitivity
+	 * of the mode that is passed in.
+	 */
+	return 1.0;
+}
+
+unsigned int CamHelper::hideFramesStartup() const
+{
+	/*
+	 * The number of frames when a camera first starts that shouldn't be
+	 * displayed as they are invalid in some way.
+	 */
+	return 0;
+}
+
+unsigned int CamHelper::hideFramesModeSwitch() const
+{
+	/* After a mode switch, many sensors return valid frames immediately. */
+	return 0;
+}
+
+unsigned int CamHelper::mistrustFramesStartup() const
+{
+	/* Many sensors return a single bad frame on start-up. */
+	return 1;
+}
+
+unsigned int CamHelper::mistrustFramesModeSwitch() const
+{
+	/* Many sensors return valid metadata immediately. */
+	return 0;
+}
+
+void CamHelper::parseEmbeddedData(Span<const uint8_t> buffer,
+				  Metadata &metadata)
+{
+	MdParser::RegisterMap registers;
+	Metadata parsedMetadata;
+
+	if (buffer.empty())
+		return;
+
+	if (parser_->parse(buffer, registers) != MdParser::Status::OK) {
+		LOG(IPARPI, Error) << "Embedded data buffer parsing failed";
+		return;
+	}
+
+	populateMetadata(registers, parsedMetadata);
+	metadata.merge(parsedMetadata);
+
+	/*
+	 * Overwrite the exposure/gain, line/frame length and sensor temperature values
+	 * in the existing DeviceStatus with values from the parsed embedded buffer.
+	 * Fetch it first in case any other fields were set meaningfully.
+	 */
+	DeviceStatus deviceStatus, parsedDeviceStatus;
+	if (metadata.get("device.status", deviceStatus) ||
+	    parsedMetadata.get("device.status", parsedDeviceStatus)) {
+		LOG(IPARPI, Error) << "DeviceStatus not found";
+		return;
+	}
+
+	deviceStatus.shutterSpeed = parsedDeviceStatus.shutterSpeed;
+	deviceStatus.analogueGain = parsedDeviceStatus.analogueGain;
+	deviceStatus.frameLength = parsedDeviceStatus.frameLength;
+	deviceStatus.lineLength = parsedDeviceStatus.lineLength;
+	if (parsedDeviceStatus.sensorTemperature)
+		deviceStatus.sensorTemperature = parsedDeviceStatus.sensorTemperature;
+
+	LOG(IPARPI, Debug) << "Metadata updated - " << deviceStatus;
+
+	metadata.set("device.status", deviceStatus);
+}
+
+void CamHelper::populateMetadata([[maybe_unused]] const MdParser::RegisterMap &registers,
+				 [[maybe_unused]] Metadata &metadata) const
+{
+}
+
+RegisterCamHelper::RegisterCamHelper(char const *camName,
+				     CamHelperCreateFunc createFunc)
+{
+	camHelpers()[std::string(camName)] = createFunc;
+}
diff --git a/src/ipa/rpi/cam_helper/cam_helper.h b/src/ipa/rpi/cam_helper/cam_helper.h
new file mode 100644
index 00000000..58a4b202
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/cam_helper.h
@@ -0,0 +1,132 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi Ltd
+ *
+ * cam_helper.h - helper class providing camera information
+ */
+#pragma once
+
+#include <memory>
+#include <string>
+#include <utility>
+
+#include <libcamera/base/span.h>
+#include <libcamera/base/utils.h>
+
+#include "controller/camera_mode.h"
+#include "controller/controller.h"
+#include "controller/metadata.h"
+#include "md_parser.h"
+
+#include "libcamera/internal/v4l2_videodevice.h"
+
+namespace RPiController {
+
+/*
+ * The CamHelper class provides a number of facilities that anyone trying
+ * to drive a camera will need to know, but which are not provided by the
+ * standard driver framework. Specifically, it provides:
+ *
+ * A "CameraMode" structure to describe extra information about the chosen
+ * mode of the driver. For example, how it is cropped from the full sensor
+ * area, how it is scaled, whether pixels are averaged compared to the full
+ * resolution.
+ *
+ * The ability to convert between number of lines of exposure and actual
+ * exposure time, and to convert between the sensor's gain codes and actual
+ * gains.
+ *
+ * A function to return the number of frames of delay between updating exposure,
+ * analogue gain and vblanking, and for the changes to take effect. For many
+ * sensors these take the values 2, 1 and 2 respectively, but sensors that are
+ * different will need to over-ride the default function provided.
+ *
+ * A function to query if the sensor outputs embedded data that can be parsed.
+ *
+ * A function to return the sensitivity of a given camera mode.
+ *
+ * A parser to parse the embedded data buffers provided by some sensors (for
+ * example, the imx219 does; the ov5647 doesn't). This allows us to know for
+ * sure the exposure and gain of the frame we're looking at. CamHelper
+ * provides functions for converting analogue gains to and from the sensor's
+ * native gain codes.
+ *
+ * Finally, a set of functions that determine how to handle the vagaries of
+ * different camera modules on start-up or when switching modes. Some
+ * modules may produce one or more frames that are not yet correctly exposed,
+ * or where the metadata may be suspect. We have the following functions:
+ * HideFramesStartup(): Tell the pipeline handler not to return this many
+ *     frames at start-up. This can also be used to hide initial frames
+ *     while the AGC and other algorithms are sorting themselves out.
+ * HideFramesModeSwitch(): Tell the pipeline handler not to return this
+ *     many frames after a mode switch (other than start-up). Some sensors
+ *     may produce innvalid frames after a mode switch; others may not.
+ * MistrustFramesStartup(): At start-up a sensor may return frames for
+ *    which we should not run any control algorithms (for example, metadata
+ *    may be invalid).
+ * MistrustFramesModeSwitch(): The number of frames, after a mode switch
+ *    (other than start-up), for which control algorithms should not run
+ *    (for example, metadata may be unreliable).
+ */
+
+class CamHelper
+{
+public:
+	static CamHelper *create(std::string const &camName);
+	CamHelper(std::unique_ptr<MdParser> parser, unsigned int frameIntegrationDiff);
+	virtual ~CamHelper();
+	void setCameraMode(const CameraMode &mode);
+	virtual void prepare(libcamera::Span<const uint8_t> buffer,
+			     Metadata &metadata);
+	virtual void process(StatisticsPtr &stats, Metadata &metadata);
+	virtual uint32_t exposureLines(const libcamera::utils::Duration exposure,
+				       const libcamera::utils::Duration lineLength) const;
+	virtual libcamera::utils::Duration exposure(uint32_t exposureLines,
+						    const libcamera::utils::Duration lineLength) const;
+	virtual std::pair<uint32_t, uint32_t> getBlanking(libcamera::utils::Duration &exposure,
+							  libcamera::utils::Duration minFrameDuration,
+							  libcamera::utils::Duration maxFrameDuration) const;
+	libcamera::utils::Duration hblankToLineLength(uint32_t hblank) const;
+	uint32_t lineLengthToHblank(const libcamera::utils::Duration &duration) const;
+	libcamera::utils::Duration lineLengthPckToDuration(uint32_t lineLengthPck) const;
+	virtual uint32_t gainCode(double gain) const = 0;
+	virtual double gain(uint32_t gainCode) const = 0;
+	virtual void getDelays(int &exposureDelay, int &gainDelay,
+			       int &vblankDelay, int &hblankDelay) const;
+	virtual bool sensorEmbeddedDataPresent() const;
+	virtual double getModeSensitivity(const CameraMode &mode) const;
+	virtual unsigned int hideFramesStartup() const;
+	virtual unsigned int hideFramesModeSwitch() const;
+	virtual unsigned int mistrustFramesStartup() const;
+	virtual unsigned int mistrustFramesModeSwitch() const;
+
+protected:
+	void parseEmbeddedData(libcamera::Span<const uint8_t> buffer,
+			       Metadata &metadata);
+	virtual void populateMetadata(const MdParser::RegisterMap &registers,
+				      Metadata &metadata) const;
+
+	std::unique_ptr<MdParser> parser_;
+	CameraMode mode_;
+
+private:
+	/*
+	 * Smallest difference between the frame length and integration time,
+	 * in units of lines.
+	 */
+	unsigned int frameIntegrationDiff_;
+};
+
+/*
+ * This is for registering camera helpers with the system, so that the
+ * CamHelper::Create function picks them up automatically.
+ */
+
+typedef CamHelper *(*CamHelperCreateFunc)();
+struct RegisterCamHelper
+{
+	RegisterCamHelper(char const *camName,
+			  CamHelperCreateFunc createFunc);
+};
+
+} /* namespace RPi */
diff --git a/src/ipa/rpi/cam_helper/cam_helper_imx219.cpp b/src/ipa/rpi/cam_helper/cam_helper_imx219.cpp
new file mode 100644
index 00000000..c3337ed0
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/cam_helper_imx219.cpp
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi Ltd
+ *
+ * cam_helper_imx219.cpp - camera helper for imx219 sensor
+ */
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+/*
+ * We have observed that the imx219 embedded data stream randomly returns junk
+ * register values. Do not rely on embedded data until this has been resolved.
+ */
+#define ENABLE_EMBEDDED_DATA 0
+
+#include "cam_helper.h"
+#if ENABLE_EMBEDDED_DATA
+#include "md_parser.h"
+#endif
+
+using namespace RPiController;
+
+/*
+ * We care about one gain register and a pair of exposure registers. Their I2C
+ * addresses from the Sony IMX219 datasheet:
+ */
+constexpr uint32_t gainReg = 0x157;
+constexpr uint32_t expHiReg = 0x15a;
+constexpr uint32_t expLoReg = 0x15b;
+constexpr uint32_t frameLengthHiReg = 0x160;
+constexpr uint32_t frameLengthLoReg = 0x161;
+constexpr uint32_t lineLengthHiReg = 0x162;
+constexpr uint32_t lineLengthLoReg = 0x163;
+constexpr std::initializer_list<uint32_t> registerList [[maybe_unused]]
+	= { expHiReg, expLoReg, gainReg, frameLengthHiReg, frameLengthLoReg,
+	    lineLengthHiReg, lineLengthLoReg };
+
+class CamHelperImx219 : public CamHelper
+{
+public:
+	CamHelperImx219();
+	uint32_t gainCode(double gain) const override;
+	double gain(uint32_t gainCode) const override;
+	unsigned int mistrustFramesModeSwitch() const override;
+	bool sensorEmbeddedDataPresent() const override;
+
+private:
+	/*
+	 * Smallest difference between the frame length and integration time,
+	 * in units of lines.
+	 */
+	static constexpr int frameIntegrationDiff = 4;
+
+	void populateMetadata(const MdParser::RegisterMap &registers,
+			      Metadata &metadata) const override;
+};
+
+CamHelperImx219::CamHelperImx219()
+#if ENABLE_EMBEDDED_DATA
+	: CamHelper(std::make_unique<MdParserSmia>(registerList), frameIntegrationDiff)
+#else
+	: CamHelper({}, frameIntegrationDiff)
+#endif
+{
+}
+
+uint32_t CamHelperImx219::gainCode(double gain) const
+{
+	return (uint32_t)(256 - 256 / gain);
+}
+
+double CamHelperImx219::gain(uint32_t gainCode) const
+{
+	return 256.0 / (256 - gainCode);
+}
+
+unsigned int CamHelperImx219::mistrustFramesModeSwitch() const
+{
+	/*
+	 * For reasons unknown, we do occasionally get a bogus metadata frame
+	 * at a mode switch (though not at start-up). Possibly warrants some
+	 * investigation, though not a big deal.
+	 */
+	return 1;
+}
+
+bool CamHelperImx219::sensorEmbeddedDataPresent() const
+{
+	return ENABLE_EMBEDDED_DATA;
+}
+
+void CamHelperImx219::populateMetadata(const MdParser::RegisterMap &registers,
+				       Metadata &metadata) const
+{
+	DeviceStatus deviceStatus;
+
+	deviceStatus.lineLength = lineLengthPckToDuration(registers.at(lineLengthHiReg) * 256 +
+							  registers.at(lineLengthLoReg));
+	deviceStatus.shutterSpeed = exposure(registers.at(expHiReg) * 256 + registers.at(expLoReg),
+					     deviceStatus.lineLength);
+	deviceStatus.analogueGain = gain(registers.at(gainReg));
+	deviceStatus.frameLength = registers.at(frameLengthHiReg) * 256 + registers.at(frameLengthLoReg);
+
+	metadata.set("device.status", deviceStatus);
+}
+
+static CamHelper *create()
+{
+	return new CamHelperImx219();
+}
+
+static RegisterCamHelper reg("imx219", &create);
diff --git a/src/ipa/rpi/cam_helper/cam_helper_imx290.cpp b/src/ipa/rpi/cam_helper/cam_helper_imx290.cpp
new file mode 100644
index 00000000..7d6f5b54
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/cam_helper_imx290.cpp
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2021, Raspberry Pi Ltd
+ *
+ * cam_helper_imx290.cpp - camera helper for imx290 sensor
+ */
+
+#include <math.h>
+
+#include "cam_helper.h"
+
+using namespace RPiController;
+
+class CamHelperImx290 : public CamHelper
+{
+public:
+	CamHelperImx290();
+	uint32_t gainCode(double gain) const override;
+	double gain(uint32_t gainCode) const override;
+	void getDelays(int &exposureDelay, int &gainDelay,
+		       int &vblankDelay, int &hblankDelay) const override;
+	unsigned int hideFramesModeSwitch() const override;
+
+private:
+	/*
+	 * Smallest difference between the frame length and integration time,
+	 * in units of lines.
+	 */
+	static constexpr int frameIntegrationDiff = 2;
+};
+
+CamHelperImx290::CamHelperImx290()
+	: CamHelper({}, frameIntegrationDiff)
+{
+}
+
+uint32_t CamHelperImx290::gainCode(double gain) const
+{
+	int code = 66.6667 * log10(gain);
+	return std::max(0, std::min(code, 0xf0));
+}
+
+double CamHelperImx290::gain(uint32_t gainCode) const
+{
+	return pow(10, 0.015 * gainCode);
+}
+
+void CamHelperImx290::getDelays(int &exposureDelay, int &gainDelay,
+				int &vblankDelay, int &hblankDelay) const
+{
+	exposureDelay = 2;
+	gainDelay = 2;
+	vblankDelay = 2;
+	hblankDelay = 2;
+}
+
+unsigned int CamHelperImx290::hideFramesModeSwitch() const
+{
+	/* After a mode switch, we seem to get 1 bad frame. */
+	return 1;
+}
+
+static CamHelper *create()
+{
+	return new CamHelperImx290();
+}
+
+static RegisterCamHelper reg("imx290", &create);
diff --git a/src/ipa/rpi/cam_helper/cam_helper_imx296.cpp b/src/ipa/rpi/cam_helper/cam_helper_imx296.cpp
new file mode 100644
index 00000000..ecb845e7
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/cam_helper_imx296.cpp
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2020, Raspberry Pi Ltd
+ *
+ * cam_helper_imx296.cpp - Camera helper for IMX296 sensor
+ */
+
+#include <algorithm>
+#include <cmath>
+#include <stddef.h>
+
+#include "cam_helper.h"
+
+using namespace RPiController;
+using libcamera::utils::Duration;
+using namespace std::literals::chrono_literals;
+
+class CamHelperImx296 : public CamHelper
+{
+public:
+	CamHelperImx296();
+	uint32_t gainCode(double gain) const override;
+	double gain(uint32_t gainCode) const override;
+	uint32_t exposureLines(const Duration exposure, const Duration lineLength) const override;
+	Duration exposure(uint32_t exposureLines, const Duration lineLength) const override;
+	void getDelays(int &exposureDelay, int &gainDelay,
+		       int &vblankDelay, int &hblankDelay) const override;
+
+private:
+	static constexpr uint32_t minExposureLines = 1;
+	static constexpr uint32_t maxGainCode = 239;
+	static constexpr Duration timePerLine = 550.0 / 37.125e6 * 1.0s;
+
+	/*
+	 * Smallest difference between the frame length and integration time,
+	 * in units of lines.
+	 */
+	static constexpr int frameIntegrationDiff = 4;
+};
+
+CamHelperImx296::CamHelperImx296()
+	: CamHelper(nullptr, frameIntegrationDiff)
+{
+}
+
+uint32_t CamHelperImx296::gainCode(double gain) const
+{
+	uint32_t code = 20 * std::log10(gain) * 10;
+	return std::min(code, maxGainCode);
+}
+
+double CamHelperImx296::gain(uint32_t gainCode) const
+{
+	return std::pow(10.0, gainCode / 200.0);
+}
+
+uint32_t CamHelperImx296::exposureLines(const Duration exposure,
+					[[maybe_unused]] const Duration lineLength) const
+{
+	return std::max<uint32_t>(minExposureLines, (exposure - 14.26us) / timePerLine);
+}
+
+Duration CamHelperImx296::exposure(uint32_t exposureLines,
+				   [[maybe_unused]] const Duration lineLength) const
+{
+	return std::max<uint32_t>(minExposureLines, exposureLines) * timePerLine + 14.26us;
+}
+
+void CamHelperImx296::getDelays(int &exposureDelay, int &gainDelay,
+				int &vblankDelay, int &hblankDelay) const
+{
+	exposureDelay = 2;
+	gainDelay = 2;
+	vblankDelay = 2;
+	hblankDelay = 2;
+}
+
+static CamHelper *create()
+{
+	return new CamHelperImx296();
+}
+
+static RegisterCamHelper reg("imx296", &create);
diff --git a/src/ipa/rpi/cam_helper/cam_helper_imx477.cpp b/src/ipa/rpi/cam_helper/cam_helper_imx477.cpp
new file mode 100644
index 00000000..bc769ca7
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/cam_helper_imx477.cpp
@@ -0,0 +1,197 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2020, Raspberry Pi Ltd
+ *
+ * cam_helper_imx477.cpp - camera helper for imx477 sensor
+ */
+
+#include <algorithm>
+#include <assert.h>
+#include <cmath>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <libcamera/base/log.h>
+
+#include "cam_helper.h"
+#include "md_parser.h"
+
+using namespace RPiController;
+using namespace libcamera;
+using libcamera::utils::Duration;
+
+namespace libcamera {
+LOG_DECLARE_CATEGORY(IPARPI)
+}
+
+/*
+ * We care about two gain registers and a pair of exposure registers. Their
+ * I2C addresses from the Sony IMX477 datasheet:
+ */
+constexpr uint32_t expHiReg = 0x0202;
+constexpr uint32_t expLoReg = 0x0203;
+constexpr uint32_t gainHiReg = 0x0204;
+constexpr uint32_t gainLoReg = 0x0205;
+constexpr uint32_t frameLengthHiReg = 0x0340;
+constexpr uint32_t frameLengthLoReg = 0x0341;
+constexpr uint32_t lineLengthHiReg = 0x0342;
+constexpr uint32_t lineLengthLoReg = 0x0343;
+constexpr uint32_t temperatureReg = 0x013a;
+constexpr std::initializer_list<uint32_t> registerList =
+	{ expHiReg, expLoReg, gainHiReg, gainLoReg, frameLengthHiReg, frameLengthLoReg,
+	  lineLengthHiReg, lineLengthLoReg, temperatureReg };
+
+class CamHelperImx477 : public CamHelper
+{
+public:
+	CamHelperImx477();
+	uint32_t gainCode(double gain) const override;
+	double gain(uint32_t gainCode) const override;
+	void prepare(libcamera::Span<const uint8_t> buffer, Metadata &metadata) override;
+	std::pair<uint32_t, uint32_t> getBlanking(Duration &exposure, Duration minFrameDuration,
+						  Duration maxFrameDuration) const override;
+	void getDelays(int &exposureDelay, int &gainDelay,
+		       int &vblankDelay, int &hblankDelay) const override;
+	bool sensorEmbeddedDataPresent() const override;
+
+private:
+	/*
+	 * Smallest difference between the frame length and integration time,
+	 * in units of lines.
+	 */
+	static constexpr int frameIntegrationDiff = 22;
+	/* Maximum frame length allowable for long exposure calculations. */
+	static constexpr int frameLengthMax = 0xffdc;
+	/* Largest long exposure scale factor given as a left shift on the frame length. */
+	static constexpr int longExposureShiftMax = 7;
+
+	void populateMetadata(const MdParser::RegisterMap &registers,
+			      Metadata &metadata) const override;
+};
+
+CamHelperImx477::CamHelperImx477()
+	: CamHelper(std::make_unique<MdParserSmia>(registerList), frameIntegrationDiff)
+{
+}
+
+uint32_t CamHelperImx477::gainCode(double gain) const
+{
+	return static_cast<uint32_t>(1024 - 1024 / gain);
+}
+
+double CamHelperImx477::gain(uint32_t gainCode) const
+{
+	return 1024.0 / (1024 - gainCode);
+}
+
+void CamHelperImx477::prepare(libcamera::Span<const uint8_t> buffer, Metadata &metadata)
+{
+	MdParser::RegisterMap registers;
+	DeviceStatus deviceStatus;
+
+	if (metadata.get("device.status", deviceStatus)) {
+		LOG(IPARPI, Error) << "DeviceStatus not found from DelayedControls";
+		return;
+	}
+
+	parseEmbeddedData(buffer, metadata);
+
+	/*
+	 * The DeviceStatus struct is first populated with values obtained from
+	 * DelayedControls. If this reports frame length is > frameLengthMax,
+	 * it means we are using a long exposure mode. Since the long exposure
+	 * scale factor is not returned back through embedded data, we must rely
+	 * on the existing exposure lines and frame length values returned by
+	 * DelayedControls.
+	 *
+	 * Otherwise, all values are updated with what is reported in the
+	 * embedded data.
+	 */
+	if (deviceStatus.frameLength > frameLengthMax) {
+		DeviceStatus parsedDeviceStatus;
+
+		metadata.get("device.status", parsedDeviceStatus);
+		parsedDeviceStatus.shutterSpeed = deviceStatus.shutterSpeed;
+		parsedDeviceStatus.frameLength = deviceStatus.frameLength;
+		metadata.set("device.status", parsedDeviceStatus);
+
+		LOG(IPARPI, Debug) << "Metadata updated for long exposure: "
+				   << parsedDeviceStatus;
+	}
+}
+
+std::pair<uint32_t, uint32_t> CamHelperImx477::getBlanking(Duration &exposure,
+							   Duration minFrameDuration,
+							   Duration maxFrameDuration) const
+{
+	uint32_t frameLength, exposureLines;
+	unsigned int shift = 0;
+
+	auto [vblank, hblank] = CamHelper::getBlanking(exposure, minFrameDuration,
+						       maxFrameDuration);
+
+	frameLength = mode_.height + vblank;
+	Duration lineLength = hblankToLineLength(hblank);
+
+	/*
+	 * Check if the frame length calculated needs to be setup for long
+	 * exposure mode. This will require us to use a long exposure scale
+	 * factor provided by a shift operation in the sensor.
+	 */
+	while (frameLength > frameLengthMax) {
+		if (++shift > longExposureShiftMax) {
+			shift = longExposureShiftMax;
+			frameLength = frameLengthMax;
+			break;
+		}
+		frameLength >>= 1;
+	}
+
+	if (shift) {
+		/* Account for any rounding in the scaled frame length value. */
+		frameLength <<= shift;
+		exposureLines = CamHelperImx477::exposureLines(exposure, lineLength);
+		exposureLines = std::min(exposureLines, frameLength - frameIntegrationDiff);
+		exposure = CamHelperImx477::exposure(exposureLines, lineLength);
+	}
+
+	return { frameLength - mode_.height, hblank };
+}
+
+void CamHelperImx477::getDelays(int &exposureDelay, int &gainDelay,
+				int &vblankDelay, int &hblankDelay) const
+{
+	exposureDelay = 2;
+	gainDelay = 2;
+	vblankDelay = 3;
+	hblankDelay = 3;
+}
+
+bool CamHelperImx477::sensorEmbeddedDataPresent() const
+{
+	return true;
+}
+
+void CamHelperImx477::populateMetadata(const MdParser::RegisterMap &registers,
+				       Metadata &metadata) const
+{
+	DeviceStatus deviceStatus;
+
+	deviceStatus.lineLength = lineLengthPckToDuration(registers.at(lineLengthHiReg) * 256 +
+							  registers.at(lineLengthLoReg));
+	deviceStatus.shutterSpeed = exposure(registers.at(expHiReg) * 256 + registers.at(expLoReg),
+					     deviceStatus.lineLength);
+	deviceStatus.analogueGain = gain(registers.at(gainHiReg) * 256 + registers.at(gainLoReg));
+	deviceStatus.frameLength = registers.at(frameLengthHiReg) * 256 + registers.at(frameLengthLoReg);
+	deviceStatus.sensorTemperature = std::clamp<int8_t>(registers.at(temperatureReg), -20, 80);
+
+	metadata.set("device.status", deviceStatus);
+}
+
+static CamHelper *create()
+{
+	return new CamHelperImx477();
+}
+
+static RegisterCamHelper reg("imx477", &create);
diff --git a/src/ipa/rpi/cam_helper/cam_helper_imx519.cpp b/src/ipa/rpi/cam_helper/cam_helper_imx519.cpp
new file mode 100644
index 00000000..c7262aa0
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/cam_helper_imx519.cpp
@@ -0,0 +1,196 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Based on cam_helper_imx477.cpp
+ * Copyright (C) 2020, Raspberry Pi Ltd
+ *
+ * cam_helper_imx519.cpp - camera helper for imx519 sensor
+ * Copyright (C) 2021, Arducam Technology co., Ltd.
+ */
+
+#include <assert.h>
+#include <cmath>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <libcamera/base/log.h>
+
+#include "cam_helper.h"
+#include "md_parser.h"
+
+using namespace RPiController;
+using namespace libcamera;
+using libcamera::utils::Duration;
+
+namespace libcamera {
+LOG_DECLARE_CATEGORY(IPARPI)
+}
+
+/*
+ * We care about two gain registers and a pair of exposure registers. Their
+ * I2C addresses from the Sony IMX519 datasheet:
+ */
+constexpr uint32_t expHiReg = 0x0202;
+constexpr uint32_t expLoReg = 0x0203;
+constexpr uint32_t gainHiReg = 0x0204;
+constexpr uint32_t gainLoReg = 0x0205;
+constexpr uint32_t frameLengthHiReg = 0x0340;
+constexpr uint32_t frameLengthLoReg = 0x0341;
+constexpr uint32_t lineLengthHiReg = 0x0342;
+constexpr uint32_t lineLengthLoReg = 0x0343;
+constexpr std::initializer_list<uint32_t> registerList =
+	{ expHiReg, expLoReg, gainHiReg, gainLoReg, frameLengthHiReg, frameLengthLoReg,
+	  lineLengthHiReg, lineLengthLoReg };
+
+class CamHelperImx519 : public CamHelper
+{
+public:
+	CamHelperImx519();
+	uint32_t gainCode(double gain) const override;
+	double gain(uint32_t gainCode) const override;
+	void prepare(libcamera::Span<const uint8_t> buffer, Metadata &metadata) override;
+	std::pair<uint32_t, uint32_t> getBlanking(Duration &exposure, Duration minFrameDuration,
+						  Duration maxFrameDuration) const override;
+	void getDelays(int &exposureDelay, int &gainDelay,
+		       int &vblankDelay, int &hblankDelay) const override;
+	bool sensorEmbeddedDataPresent() const override;
+
+private:
+	/*
+	 * Smallest difference between the frame length and integration time,
+	 * in units of lines.
+	 */
+	static constexpr int frameIntegrationDiff = 32;
+	/* Maximum frame length allowable for long exposure calculations. */
+	static constexpr int frameLengthMax = 0xffdc;
+	/* Largest long exposure scale factor given as a left shift on the frame length. */
+	static constexpr int longExposureShiftMax = 7;
+
+	void populateMetadata(const MdParser::RegisterMap &registers,
+			      Metadata &metadata) const override;
+};
+
+CamHelperImx519::CamHelperImx519()
+	: CamHelper(std::make_unique<MdParserSmia>(registerList), frameIntegrationDiff)
+{
+}
+
+uint32_t CamHelperImx519::gainCode(double gain) const
+{
+	return static_cast<uint32_t>(1024 - 1024 / gain);
+}
+
+double CamHelperImx519::gain(uint32_t gainCode) const
+{
+	return 1024.0 / (1024 - gainCode);
+}
+
+void CamHelperImx519::prepare(libcamera::Span<const uint8_t> buffer, Metadata &metadata)
+{
+	MdParser::RegisterMap registers;
+	DeviceStatus deviceStatus;
+
+	if (metadata.get("device.status", deviceStatus)) {
+		LOG(IPARPI, Error) << "DeviceStatus not found from DelayedControls";
+		return;
+	}
+
+	parseEmbeddedData(buffer, metadata);
+
+	/*
+	 * The DeviceStatus struct is first populated with values obtained from
+	 * DelayedControls. If this reports frame length is > frameLengthMax,
+	 * it means we are using a long exposure mode. Since the long exposure
+	 * scale factor is not returned back through embedded data, we must rely
+	 * on the existing exposure lines and frame length values returned by
+	 * DelayedControls.
+	 *
+	 * Otherwise, all values are updated with what is reported in the
+	 * embedded data.
+	 */
+	if (deviceStatus.frameLength > frameLengthMax) {
+		DeviceStatus parsedDeviceStatus;
+
+		metadata.get("device.status", parsedDeviceStatus);
+		parsedDeviceStatus.shutterSpeed = deviceStatus.shutterSpeed;
+		parsedDeviceStatus.frameLength = deviceStatus.frameLength;
+		metadata.set("device.status", parsedDeviceStatus);
+
+		LOG(IPARPI, Debug) << "Metadata updated for long exposure: "
+				   << parsedDeviceStatus;
+	}
+}
+
+std::pair<uint32_t, uint32_t> CamHelperImx519::getBlanking(Duration &exposure,
+							   Duration minFrameDuration,
+							   Duration maxFrameDuration) const
+{
+	uint32_t frameLength, exposureLines;
+	unsigned int shift = 0;
+
+	auto [vblank, hblank] = CamHelper::getBlanking(exposure, minFrameDuration,
+						       maxFrameDuration);
+
+	frameLength = mode_.height + vblank;
+	Duration lineLength = hblankToLineLength(hblank);
+
+	/*
+	 * Check if the frame length calculated needs to be setup for long
+	 * exposure mode. This will require us to use a long exposure scale
+	 * factor provided by a shift operation in the sensor.
+	 */
+	while (frameLength > frameLengthMax) {
+		if (++shift > longExposureShiftMax) {
+			shift = longExposureShiftMax;
+			frameLength = frameLengthMax;
+			break;
+		}
+		frameLength >>= 1;
+	}
+
+	if (shift) {
+		/* Account for any rounding in the scaled frame length value. */
+		frameLength <<= shift;
+		exposureLines = CamHelperImx519::exposureLines(exposure, lineLength);
+		exposureLines = std::min(exposureLines, frameLength - frameIntegrationDiff);
+		exposure = CamHelperImx519::exposure(exposureLines, lineLength);
+	}
+
+	return { frameLength - mode_.height, hblank };
+}
+
+void CamHelperImx519::getDelays(int &exposureDelay, int &gainDelay,
+				int &vblankDelay, int &hblankDelay) const
+{
+	exposureDelay = 2;
+	gainDelay = 2;
+	vblankDelay = 3;
+	hblankDelay = 3;
+}
+
+bool CamHelperImx519::sensorEmbeddedDataPresent() const
+{
+	return true;
+}
+
+void CamHelperImx519::populateMetadata(const MdParser::RegisterMap &registers,
+				       Metadata &metadata) const
+{
+	DeviceStatus deviceStatus;
+
+	deviceStatus.lineLength = lineLengthPckToDuration(registers.at(lineLengthHiReg) * 256 +
+							  registers.at(lineLengthLoReg));
+	deviceStatus.shutterSpeed = exposure(registers.at(expHiReg) * 256 + registers.at(expLoReg),
+					     deviceStatus.lineLength);
+	deviceStatus.analogueGain = gain(registers.at(gainHiReg) * 256 + registers.at(gainLoReg));
+	deviceStatus.frameLength = registers.at(frameLengthHiReg) * 256 + registers.at(frameLengthLoReg);
+
+	metadata.set("device.status", deviceStatus);
+}
+
+static CamHelper *create()
+{
+	return new CamHelperImx519();
+}
+
+static RegisterCamHelper reg("imx519", &create);
diff --git a/src/ipa/rpi/cam_helper/cam_helper_imx708.cpp b/src/ipa/rpi/cam_helper/cam_helper_imx708.cpp
new file mode 100644
index 00000000..641ba18f
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/cam_helper_imx708.cpp
@@ -0,0 +1,359 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2022, Raspberry Pi Ltd
+ *
+ * cam_helper_imx708.cpp - camera helper for imx708 sensor
+ */
+
+#include <cmath>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <libcamera/base/log.h>
+
+#include "controller/pdaf_data.h"
+
+#include "cam_helper.h"
+#include "md_parser.h"
+
+using namespace RPiController;
+using namespace libcamera;
+using libcamera::utils::Duration;
+
+namespace libcamera {
+LOG_DECLARE_CATEGORY(IPARPI)
+}
+
+/*
+ * We care about two gain registers and a pair of exposure registers. Their
+ * I2C addresses from the Sony imx708 datasheet:
+ */
+constexpr uint32_t expHiReg = 0x0202;
+constexpr uint32_t expLoReg = 0x0203;
+constexpr uint32_t gainHiReg = 0x0204;
+constexpr uint32_t gainLoReg = 0x0205;
+constexpr uint32_t frameLengthHiReg = 0x0340;
+constexpr uint32_t frameLengthLoReg = 0x0341;
+constexpr uint32_t lineLengthHiReg = 0x0342;
+constexpr uint32_t lineLengthLoReg = 0x0343;
+constexpr uint32_t temperatureReg = 0x013a;
+constexpr std::initializer_list<uint32_t> registerList =
+	{ expHiReg, expLoReg, gainHiReg, gainLoReg, lineLengthHiReg,
+	  lineLengthLoReg, frameLengthHiReg, frameLengthLoReg, temperatureReg };
+
+class CamHelperImx708 : public CamHelper
+{
+public:
+	CamHelperImx708();
+	uint32_t gainCode(double gain) const override;
+	double gain(uint32_t gain_code) const override;
+	void prepare(libcamera::Span<const uint8_t> buffer, Metadata &metadata) override;
+	void process(StatisticsPtr &stats, Metadata &metadata) override;
+	std::pair<uint32_t, uint32_t> getBlanking(Duration &exposure, Duration minFrameDuration,
+						  Duration maxFrameDuration) const override;
+	void getDelays(int &exposureDelay, int &gainDelay,
+		       int &vblankDelay, int &hblankDelay) const override;
+	bool sensorEmbeddedDataPresent() const override;
+	double getModeSensitivity(const CameraMode &mode) const override;
+	unsigned int hideFramesModeSwitch() const override { return 1; } // seems to be required for HDR
+
+private:
+	/*
+	 * Smallest difference between the frame length and integration time,
+	 * in units of lines.
+	 */
+	static constexpr int frameIntegrationDiff = 22;
+	/* Maximum frame length allowable for long exposure calculations. */
+	static constexpr int frameLengthMax = 0xffdc;
+	/* Largest long exposure scale factor given as a left shift on the frame length. */
+	static constexpr int longExposureShiftMax = 7;
+
+	static constexpr int pdafStatsRows = 12;
+	static constexpr int pdafStatsCols = 16;
+
+	void populateMetadata(const MdParser::RegisterMap &registers,
+			      Metadata &metadata) const override;
+
+	static bool parsePdafData(const uint8_t *ptr, size_t len, unsigned bpp,
+				  PdafRegions &pdaf);
+
+	bool parseAEHist(const uint8_t *ptr, size_t len, unsigned bpp);
+	void putAGCStatistics(StatisticsPtr stats);
+
+	Histogram aeHistLinear_;
+	uint32_t aeHistAverage_;
+	bool aeHistValid_;
+};
+
+CamHelperImx708::CamHelperImx708()
+	: CamHelper(std::make_unique<MdParserSmia>(registerList), frameIntegrationDiff),
+	  aeHistLinear_{}, aeHistAverage_(0), aeHistValid_(false)
+{
+}
+
+uint32_t CamHelperImx708::gainCode(double gain) const
+{
+	return static_cast<uint32_t>(1024 - 1024 / gain);
+}
+
+double CamHelperImx708::gain(uint32_t gain_code) const
+{
+	return 1024.0 / (1024 - gain_code);
+}
+
+void CamHelperImx708::prepare(libcamera::Span<const uint8_t> buffer, Metadata &metadata)
+{
+	MdParser::RegisterMap registers;
+	DeviceStatus deviceStatus;
+
+	LOG(IPARPI, Debug) << "Embedded buffer size: " << buffer.size();
+
+	if (metadata.get("device.status", deviceStatus)) {
+		LOG(IPARPI, Error) << "DeviceStatus not found from DelayedControls";
+		return;
+	}
+
+	parseEmbeddedData(buffer, metadata);
+
+	/*
+	 * Parse PDAF data, which we expect to occupy the third scanline
+	 * of embedded data. As PDAF is quite sensor-specific, it's parsed here.
+	 */
+	size_t bytesPerLine = (mode_.width * mode_.bitdepth) >> 3;
+
+	if (buffer.size() > 2 * bytesPerLine) {
+		PdafRegions pdaf;
+		if (parsePdafData(&buffer[2 * bytesPerLine],
+				  buffer.size() - 2 * bytesPerLine,
+				  mode_.bitdepth, pdaf))
+			metadata.set("pdaf.regions", pdaf);
+	}
+
+	/* Parse AE-HIST data where present */
+	if (buffer.size() > 3 * bytesPerLine) {
+		aeHistValid_ = parseAEHist(&buffer[3 * bytesPerLine],
+					   buffer.size() - 3 * bytesPerLine,
+					   mode_.bitdepth);
+	}
+
+	/*
+	 * The DeviceStatus struct is first populated with values obtained from
+	 * DelayedControls. If this reports frame length is > frameLengthMax,
+	 * it means we are using a long exposure mode. Since the long exposure
+	 * scale factor is not returned back through embedded data, we must rely
+	 * on the existing exposure lines and frame length values returned by
+	 * DelayedControls.
+	 *
+	 * Otherwise, all values are updated with what is reported in the
+	 * embedded data.
+	 */
+	if (deviceStatus.frameLength > frameLengthMax) {
+		DeviceStatus parsedDeviceStatus;
+
+		metadata.get("device.status", parsedDeviceStatus);
+		parsedDeviceStatus.shutterSpeed = deviceStatus.shutterSpeed;
+		parsedDeviceStatus.frameLength = deviceStatus.frameLength;
+		metadata.set("device.status", parsedDeviceStatus);
+
+		LOG(IPARPI, Debug) << "Metadata updated for long exposure: "
+				   << parsedDeviceStatus;
+	}
+}
+
+void CamHelperImx708::process(StatisticsPtr &stats, [[maybe_unused]] Metadata &metadata)
+{
+	if (aeHistValid_)
+		putAGCStatistics(stats);
+}
+
+std::pair<uint32_t, uint32_t> CamHelperImx708::getBlanking(Duration &exposure,
+							   Duration minFrameDuration,
+							   Duration maxFrameDuration) const
+{
+	uint32_t frameLength, exposureLines;
+	unsigned int shift = 0;
+
+	auto [vblank, hblank] = CamHelper::getBlanking(exposure, minFrameDuration,
+						       maxFrameDuration);
+
+	frameLength = mode_.height + vblank;
+	Duration lineLength = hblankToLineLength(hblank);
+
+	/*
+	 * Check if the frame length calculated needs to be setup for long
+	 * exposure mode. This will require us to use a long exposure scale
+	 * factor provided by a shift operation in the sensor.
+	 */
+	while (frameLength > frameLengthMax) {
+		if (++shift > longExposureShiftMax) {
+			shift = longExposureShiftMax;
+			frameLength = frameLengthMax;
+			break;
+		}
+		frameLength >>= 1;
+	}
+
+	if (shift) {
+		/* Account for any rounding in the scaled frame length value. */
+		frameLength <<= shift;
+		exposureLines = CamHelper::exposureLines(exposure, lineLength);
+		exposureLines = std::min(exposureLines, frameLength - frameIntegrationDiff);
+		exposure = CamHelper::exposure(exposureLines, lineLength);
+	}
+
+	return { frameLength - mode_.height, hblank };
+}
+
+void CamHelperImx708::getDelays(int &exposureDelay, int &gainDelay,
+				int &vblankDelay, int &hblankDelay) const
+{
+	exposureDelay = 2;
+	gainDelay = 2;
+	vblankDelay = 3;
+	hblankDelay = 3;
+}
+
+bool CamHelperImx708::sensorEmbeddedDataPresent() const
+{
+	return true;
+}
+
+double CamHelperImx708::getModeSensitivity(const CameraMode &mode) const
+{
+	/* In binned modes, sensitivity increases by a factor of 2 */
+	return (mode.width > 2304) ? 1.0 : 2.0;
+}
+
+void CamHelperImx708::populateMetadata(const MdParser::RegisterMap &registers,
+				       Metadata &metadata) const
+{
+	DeviceStatus deviceStatus;
+
+	deviceStatus.lineLength = lineLengthPckToDuration(registers.at(lineLengthHiReg) * 256 +
+							  registers.at(lineLengthLoReg));
+	deviceStatus.shutterSpeed = exposure(registers.at(expHiReg) * 256 + registers.at(expLoReg),
+					     deviceStatus.lineLength);
+	deviceStatus.analogueGain = gain(registers.at(gainHiReg) * 256 + registers.at(gainLoReg));
+	deviceStatus.frameLength = registers.at(frameLengthHiReg) * 256 + registers.at(frameLengthLoReg);
+	deviceStatus.sensorTemperature = std::clamp<int8_t>(registers.at(temperatureReg), -20, 80);
+
+	metadata.set("device.status", deviceStatus);
+}
+
+bool CamHelperImx708::parsePdafData(const uint8_t *ptr, size_t len,
+				    unsigned bpp, PdafRegions &pdaf)
+{
+	size_t step = bpp >> 1; /* bytes per PDAF grid entry */
+
+	if (bpp < 10 || bpp > 12 || len < 194 * step || ptr[0] != 0 || ptr[1] >= 0x40) {
+		LOG(IPARPI, Error) << "PDAF data in unsupported format";
+		return false;
+	}
+
+	pdaf.init({ pdafStatsCols, pdafStatsRows });
+
+	ptr += 2 * step;
+	for (unsigned i = 0; i < pdafStatsRows; ++i) {
+		for (unsigned j = 0; j < pdafStatsCols; ++j) {
+			unsigned c = (ptr[0] << 3) | (ptr[1] >> 5);
+			int p = (((ptr[1] & 0x0F) - (ptr[1] & 0x10)) << 6) | (ptr[2] >> 2);
+			PdafData pdafData;
+			pdafData.conf = c;
+			pdafData.phase = c ? p : 0;
+			pdaf.set(libcamera::Point(j, i), { pdafData, 1, 0 });
+			ptr += step;
+		}
+	}
+
+	return true;
+}
+
+bool CamHelperImx708::parseAEHist(const uint8_t *ptr, size_t len, unsigned bpp)
+{
+	static constexpr unsigned int PipelineBits = Statistics::NormalisationFactorPow2;
+
+	uint64_t count = 0, sum = 0;
+	size_t step = bpp >> 1; /* bytes per histogram bin */
+	uint32_t hist[128];
+
+	if (len < 144 * step)
+		return false;
+
+	/*
+	 * Read the 128 bin linear histogram, which by default covers
+	 * the full range of the HDR shortest exposure (small values are
+	 * expected to dominate, so pixel-value resolution will be poor).
+	 */
+	for (unsigned i = 0; i < 128; ++i) {
+		if (ptr[3] != 0x55)
+			return false;
+		uint32_t c = (ptr[0] << 14) + (ptr[1] << 6) + (ptr[2] >> 2);
+		hist[i] = c >> 2; /* pixels to quads */
+		if (i != 0) {
+			count += c;
+			sum += c *
+			       (i * (1u << (PipelineBits - 7)) +
+				(1u << (PipelineBits - 8)));
+		}
+		ptr += step;
+	}
+
+	/*
+	 * Now use the first 9 bins of the log histogram (these should be
+	 * subdivisions of the smallest linear bin), to get a more accurate
+	 * average value. Don't assume that AEHIST1_AVERAGE is present.
+	 */
+	for (unsigned i = 0; i < 9; ++i) {
+		if (ptr[3] != 0x55)
+			return false;
+		uint32_t c = (ptr[0] << 14) + (ptr[1] << 6) + (ptr[2] >> 2);
+		count += c;
+		sum += c *
+		       ((3u << PipelineBits) >> (17 - i));
+		ptr += step;
+	}
+	if ((unsigned)((ptr[0] << 12) + (ptr[1] << 4) + (ptr[2] >> 4)) !=
+	    hist[1]) {
+		LOG(IPARPI, Error) << "Lin/Log histogram mismatch";
+		return false;
+	}
+
+	aeHistLinear_ = Histogram(hist, 128);
+	aeHistAverage_ = count ? (sum / count) : 0;
+
+	return count != 0;
+}
+
+void CamHelperImx708::putAGCStatistics(StatisticsPtr stats)
+{
+	/*
+	 * For HDR mode, copy sensor's AE/AGC statistics over ISP's, so the
+	 * AGC algorithm sees a linear response to exposure and gain changes.
+	 *
+	 * Histogram: Just copy the "raw" histogram over the tone-mapped one,
+	 * although they have different distributions (raw values are lower).
+	 * Tuning should either ignore it, or constrain for highlights only.
+	 *
+	 * Average: Overwrite all regional averages with a global raw average,
+	 * scaled by a fiddle-factor so that a conventional (non-HDR) y_target
+	 * of e.g. 0.17 will map to a suitable level for HDR.
+	 */
+	stats->yHist = aeHistLinear_;
+
+	constexpr unsigned int HdrHeadroomFactor = 4;
+	uint64_t v = HdrHeadroomFactor * aeHistAverage_;
+	for (auto &region : stats->agcRegions) {
+		region.val.rSum = region.val.gSum = region.val.bSum = region.counted * v;
+	}
+}
+
+static CamHelper *create()
+{
+	return new CamHelperImx708();
+}
+
+static RegisterCamHelper reg("imx708", &create);
+static RegisterCamHelper regWide("imx708_wide", &create);
+static RegisterCamHelper regNoIr("imx708_noir", &create);
+static RegisterCamHelper regWideNoIr("imx708_wide_noir", &create);
diff --git a/src/ipa/rpi/cam_helper/cam_helper_ov5647.cpp b/src/ipa/rpi/cam_helper/cam_helper_ov5647.cpp
new file mode 100644
index 00000000..5a99083d
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/cam_helper_ov5647.cpp
@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi Ltd
+ *
+ * cam_helper_ov5647.cpp - camera information for ov5647 sensor
+ */
+
+#include <assert.h>
+
+#include "cam_helper.h"
+
+using namespace RPiController;
+
+class CamHelperOv5647 : public CamHelper
+{
+public:
+	CamHelperOv5647();
+	uint32_t gainCode(double gain) const override;
+	double gain(uint32_t gainCode) const override;
+	void getDelays(int &exposureDelay, int &gainDelay,
+		       int &vblankDelay, int &hblankDelay) const override;
+	unsigned int hideFramesStartup() const override;
+	unsigned int hideFramesModeSwitch() const override;
+	unsigned int mistrustFramesStartup() const override;
+	unsigned int mistrustFramesModeSwitch() const override;
+
+private:
+	/*
+	 * Smallest difference between the frame length and integration time,
+	 * in units of lines.
+	 */
+	static constexpr int frameIntegrationDiff = 4;
+};
+
+/*
+ * OV5647 doesn't output metadata, so we have to use the "unicam parser" which
+ * works by counting frames.
+ */
+
+CamHelperOv5647::CamHelperOv5647()
+	: CamHelper({}, frameIntegrationDiff)
+{
+}
+
+uint32_t CamHelperOv5647::gainCode(double gain) const
+{
+	return static_cast<uint32_t>(gain * 16.0);
+}
+
+double CamHelperOv5647::gain(uint32_t gainCode) const
+{
+	return static_cast<double>(gainCode) / 16.0;
+}
+
+void CamHelperOv5647::getDelays(int &exposureDelay, int &gainDelay,
+				int &vblankDelay, int &hblankDelay) const
+{
+	/*
+	 * We run this sensor in a mode where the gain delay is bumped up to
+	 * 2. It seems to be the only way to make the delays "predictable".
+	 */
+	exposureDelay = 2;
+	gainDelay = 2;
+	vblankDelay = 2;
+	hblankDelay = 2;
+}
+
+unsigned int CamHelperOv5647::hideFramesStartup() const
+{
+	/*
+	 * On startup, we get a couple of under-exposed frames which
+	 * we don't want shown.
+	 */
+	return 2;
+}
+
+unsigned int CamHelperOv5647::hideFramesModeSwitch() const
+{
+	/*
+	 * After a mode switch, we get a couple of under-exposed frames which
+	 * we don't want shown.
+	 */
+	return 2;
+}
+
+unsigned int CamHelperOv5647::mistrustFramesStartup() const
+{
+	/*
+	 * First couple of frames are under-exposed and are no good for control
+	 * algos.
+	 */
+	return 2;
+}
+
+unsigned int CamHelperOv5647::mistrustFramesModeSwitch() const
+{
+	/*
+	 * First couple of frames are under-exposed even after a simple
+	 * mode switch, and are no good for control algos.
+	 */
+	return 2;
+}
+
+static CamHelper *create()
+{
+	return new CamHelperOv5647();
+}
+
+static RegisterCamHelper reg("ov5647", &create);
diff --git a/src/ipa/rpi/cam_helper/cam_helper_ov9281.cpp b/src/ipa/rpi/cam_helper/cam_helper_ov9281.cpp
new file mode 100644
index 00000000..86c5bc4c
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/cam_helper_ov9281.cpp
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2021, Raspberry Pi Ltd
+ *
+ * cam_helper_ov9281.cpp - camera information for ov9281 sensor
+ */
+
+#include <assert.h>
+
+#include "cam_helper.h"
+
+using namespace RPiController;
+
+class CamHelperOv9281 : public CamHelper
+{
+public:
+	CamHelperOv9281();
+	uint32_t gainCode(double gain) const override;
+	double gain(uint32_t gainCode) const override;
+	void getDelays(int &exposureDelay, int &gainDelay,
+		       int &vblankDelay, int &hblankDelay) const override;
+
+private:
+	/*
+	 * Smallest difference between the frame length and integration time,
+	 * in units of lines.
+	 */
+	static constexpr int frameIntegrationDiff = 4;
+};
+
+/*
+ * OV9281 doesn't output metadata, so we have to use the "unicam parser" which
+ * works by counting frames.
+ */
+
+CamHelperOv9281::CamHelperOv9281()
+	: CamHelper({}, frameIntegrationDiff)
+{
+}
+
+uint32_t CamHelperOv9281::gainCode(double gain) const
+{
+	return static_cast<uint32_t>(gain * 16.0);
+}
+
+double CamHelperOv9281::gain(uint32_t gainCode) const
+{
+	return static_cast<double>(gainCode) / 16.0;
+}
+
+void CamHelperOv9281::getDelays(int &exposureDelay, int &gainDelay,
+				int &vblankDelay, int &hblankDelay) const
+{
+	/* The driver appears to behave as follows: */
+	exposureDelay = 2;
+	gainDelay = 2;
+	vblankDelay = 2;
+	hblankDelay = 2;
+}
+
+static CamHelper *create()
+{
+	return new CamHelperOv9281();
+}
+
+static RegisterCamHelper reg("ov9281", &create);
diff --git a/src/ipa/rpi/cam_helper/md_parser.h b/src/ipa/rpi/cam_helper/md_parser.h
new file mode 100644
index 00000000..77d557aa
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/md_parser.h
@@ -0,0 +1,155 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi Ltd
+ *
+ * md_parser.h - image sensor metadata parser interface
+ */
+#pragma once
+
+#include <initializer_list>
+#include <map>
+#include <optional>
+#include <stdint.h>
+
+#include <libcamera/base/span.h>
+
+/*
+ * Camera metadata parser class. Usage as shown below.
+ *
+ * Setup:
+ *
+ * Usually the metadata parser will be made as part of the CamHelper class so
+ * application code doesn't have to worry which kind to instantiate. But for
+ * the sake of example let's suppose we're parsing imx219 metadata.
+ *
+ * MdParser *parser = new MdParserSmia({ expHiReg, expLoReg, gainReg });
+ * parser->SetBitsPerPixel(bpp);
+ * parser->SetLineLengthBytes(pitch);
+ * parser->SetNumLines(2);
+ *
+ * Note 1: if you don't know how many lines there are, the size of the input
+ * buffer is used as a limit instead.
+ *
+ * Note 2: if you don't know the line length, you can leave the line length unset
+ * (or set to zero) and the parser will hunt for the line start instead.
+ *
+ * Then on every frame:
+ *
+ * RegisterMap registers;
+ * if (parser->Parse(buffer, registers) != MdParser::OK)
+ *     much badness;
+ * Metadata metadata;
+ * CamHelper::PopulateMetadata(registers, metadata);
+ *
+ * (Note that the CamHelper class converts to/from exposure lines and time,
+ * and gain_code / actual gain.)
+ *
+ * If you suspect your embedded data may have changed its layout, change any line
+ * lengths, number of lines, bits per pixel etc. that are different, and
+ * then:
+ *
+ * parser->Reset();
+ *
+ * before calling Parse again.
+ */
+
+namespace RPiController {
+
+/* Abstract base class from which other metadata parsers are derived. */
+
+class MdParser
+{
+public:
+	using RegisterMap = std::map<uint32_t, uint32_t>;
+
+	/*
+	 * Parser status codes:
+	 * OK       - success
+	 * NOTFOUND - value such as exposure or gain was not found
+	 * ERROR    - all other errors
+	 */
+	enum Status {
+		OK = 0,
+		NOTFOUND = 1,
+		ERROR = 2
+	};
+
+	MdParser()
+		: reset_(true), bitsPerPixel_(0), numLines_(0), lineLengthBytes_(0)
+	{
+	}
+
+	virtual ~MdParser() = default;
+
+	void reset()
+	{
+		reset_ = true;
+	}
+
+	void setBitsPerPixel(int bpp)
+	{
+		bitsPerPixel_ = bpp;
+	}
+
+	void setNumLines(unsigned int numLines)
+	{
+		numLines_ = numLines;
+	}
+
+	void setLineLengthBytes(unsigned int numBytes)
+	{
+		lineLengthBytes_ = numBytes;
+	}
+
+	virtual Status parse(libcamera::Span<const uint8_t> buffer,
+			     RegisterMap &registers) = 0;
+
+protected:
+	bool reset_;
+	int bitsPerPixel_;
+	unsigned int numLines_;
+	unsigned int lineLengthBytes_;
+};
+
+/*
+ * This isn't a full implementation of a metadata parser for SMIA sensors,
+ * however, it does provide the findRegs function which will prove useful and
+ * make it easier to implement parsers for other SMIA-like sensors (see
+ * md_parser_imx219.cpp for an example).
+ */
+
+class MdParserSmia final : public MdParser
+{
+public:
+	MdParserSmia(std::initializer_list<uint32_t> registerList);
+
+	MdParser::Status parse(libcamera::Span<const uint8_t> buffer,
+			       RegisterMap &registers) override;
+
+private:
+	/* Maps register address to offset in the buffer. */
+	using OffsetMap = std::map<uint32_t, std::optional<uint32_t>>;
+
+	/*
+	 * Note that error codes > 0 are regarded as non-fatal; codes < 0
+	 * indicate a bad data buffer. Status codes are:
+	 * ParseOk     - found all registers, much happiness
+	 * MissingRegs - some registers found; should this be a hard error?
+	 * The remaining codes are all hard errors.
+	 */
+	enum ParseStatus {
+		ParseOk      =  0,
+		MissingRegs  =  1,
+		NoLineStart  = -1,
+		IllegalTag   = -2,
+		BadDummy     = -3,
+		BadLineEnd   = -4,
+		BadPadding   = -5
+	};
+
+	ParseStatus findRegs(libcamera::Span<const uint8_t> buffer);
+
+	OffsetMap offsets_;
+};
+
+} /* namespace RPi */
diff --git a/src/ipa/rpi/cam_helper/md_parser_smia.cpp b/src/ipa/rpi/cam_helper/md_parser_smia.cpp
new file mode 100644
index 00000000..210787ed
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/md_parser_smia.cpp
@@ -0,0 +1,149 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019-2021, Raspberry Pi Ltd
+ *
+ * md_parser_smia.cpp - SMIA specification based embedded data parser
+ */
+
+#include <libcamera/base/log.h>
+#include "md_parser.h"
+
+using namespace RPiController;
+using namespace libcamera;
+
+/*
+ * This function goes through the embedded data to find the offsets (not
+ * values!), in the data block, where the values of the given registers can
+ * subsequently be found.
+ *
+ * Embedded data tag bytes, from Sony IMX219 datasheet but general to all SMIA
+ * sensors, I think.
+ */
+
+constexpr unsigned int LineStart = 0x0a;
+constexpr unsigned int LineEndTag = 0x07;
+constexpr unsigned int RegHiBits = 0xaa;
+constexpr unsigned int RegLowBits = 0xa5;
+constexpr unsigned int RegValue = 0x5a;
+constexpr unsigned int RegSkip = 0x55;
+
+MdParserSmia::MdParserSmia(std::initializer_list<uint32_t> registerList)
+{
+	for (auto r : registerList)
+		offsets_[r] = {};
+}
+
+MdParser::Status MdParserSmia::parse(libcamera::Span<const uint8_t> buffer,
+				     RegisterMap &registers)
+{
+	if (reset_) {
+		/*
+		 * Search again through the metadata for all the registers
+		 * requested.
+		 */
+		ASSERT(bitsPerPixel_);
+
+		for (const auto &kv : offsets_)
+			offsets_[kv.first] = {};
+
+		ParseStatus ret = findRegs(buffer);
+		/*
+		 * > 0 means "worked partially but parse again next time",
+		 * < 0 means "hard error".
+		 *
+		 * In either case, we retry parsing on the next frame.
+		 */
+		if (ret != ParseOk)
+			return ERROR;
+
+		reset_ = false;
+	}
+
+	/* Populate the register values requested. */
+	registers.clear();
+	for (const auto &[reg, offset] : offsets_) {
+		if (!offset) {
+			reset_ = true;
+			return NOTFOUND;
+		}
+		registers[reg] = buffer[offset.value()];
+	}
+
+	return OK;
+}
+
+MdParserSmia::ParseStatus MdParserSmia::findRegs(libcamera::Span<const uint8_t> buffer)
+{
+	ASSERT(offsets_.size());
+
+	if (buffer[0] != LineStart)
+		return NoLineStart;
+
+	unsigned int currentOffset = 1; /* after the LineStart */
+	unsigned int currentLineStart = 0, currentLine = 0;
+	unsigned int regNum = 0, regsDone = 0;
+
+	while (1) {
+		int tag = buffer[currentOffset++];
+
+		if ((bitsPerPixel_ == 10 &&
+		     (currentOffset + 1 - currentLineStart) % 5 == 0) ||
+		    (bitsPerPixel_ == 12 &&
+		     (currentOffset + 1 - currentLineStart) % 3 == 0)) {
+			if (buffer[currentOffset++] != RegSkip)
+				return BadDummy;
+		}
+
+		int dataByte = buffer[currentOffset++];
+
+		if (tag == LineEndTag) {
+			if (dataByte != LineEndTag)
+				return BadLineEnd;
+
+			if (numLines_ && ++currentLine == numLines_)
+				return MissingRegs;
+
+			if (lineLengthBytes_) {
+				currentOffset = currentLineStart + lineLengthBytes_;
+
+				/* Require whole line to be in the buffer (if buffer size set). */
+				if (buffer.size() &&
+				    currentOffset + lineLengthBytes_ > buffer.size())
+					return MissingRegs;
+
+				if (buffer[currentOffset] != LineStart)
+					return NoLineStart;
+			} else {
+				/* allow a zero line length to mean "hunt for the next line" */
+				while (currentOffset < buffer.size() &&
+				       buffer[currentOffset] != LineStart)
+					currentOffset++;
+
+				if (currentOffset == buffer.size())
+					return NoLineStart;
+			}
+
+			/* inc currentOffset to after LineStart */
+			currentLineStart = currentOffset++;
+		} else {
+			if (tag == RegHiBits)
+				regNum = (regNum & 0xff) | (dataByte << 8);
+			else if (tag == RegLowBits)
+				regNum = (regNum & 0xff00) | dataByte;
+			else if (tag == RegSkip)
+				regNum++;
+			else if (tag == RegValue) {
+				auto reg = offsets_.find(regNum);
+
+				if (reg != offsets_.end()) {
+					offsets_[regNum] = currentOffset - 1;
+
+					if (++regsDone == offsets_.size())
+						return ParseOk;
+				}
+				regNum++;
+			} else
+				return IllegalTag;
+		}
+	}
+}
diff --git a/src/ipa/rpi/cam_helper/meson.build b/src/ipa/rpi/cam_helper/meson.build
new file mode 100644
index 00000000..bdf2db8e
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/meson.build
@@ -0,0 +1,26 @@
+# SPDX-License-Identifier: CC0-1.0
+
+rpi_ipa_cam_helper_sources = files([
+    'cam_helper.cpp',
+    'cam_helper_ov5647.cpp',
+    'cam_helper_imx219.cpp',
+    'cam_helper_imx290.cpp',
+    'cam_helper_imx296.cpp',
+    'cam_helper_imx477.cpp',
+    'cam_helper_imx519.cpp',
+    'cam_helper_imx708.cpp',
+    'cam_helper_ov9281.cpp',
+    'md_parser_smia.cpp',
+])
+
+rpi_ipa_cam_helper_includes = [
+    include_directories('..'),
+]
+
+rpi_ipa_cam_helper_deps = [
+    libcamera_private,
+]
+
+rpi_ipa_cam_helper_lib = static_library('rpi_ipa_cam_helper', rpi_ipa_cam_helper_sources,
+                                        include_directories : rpi_ipa_cam_helper_includes,
+                                        dependencies : rpi_ipa_cam_helper_deps)