ipa: raspberrypi: Switch the AGC/Lux code to use utils::Duration

Convert the core AGC and Lux controller code to use
utils::Duration for all exposure time related variables and
calculations.

Convert the exposure/shutter time fields in AgcStatus and DeviceStatus
to use utils::Duration.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: David Plowman <david.plowman@raspberrypi.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

6 files changed, 85 insertions, 66 deletions

diff --git a/src/ipa/raspberrypi/controller/agc_status.h b/src/ipa/raspberrypi/controller/agc_status.h
index 10381c90..5d50e177 100644
--- a/src/ipa/raspberrypi/controller/agc_status.h
+++ b/src/ipa/raspberrypi/controller/agc_status.h
@@ -6,6 +6,8 @@
  */
 #pragma once
 
+#include "libcamera/internal/utils.h"
+
 // The AGC algorithm should post the following structure into the image's
 // "agc.status" metadata.
 
@@ -18,17 +20,17 @@ extern "C" {
 // ignored until then.
 
 struct AgcStatus {
-	double total_exposure_value; // value for all exposure and gain for this image
-	double target_exposure_value; // (unfiltered) target total exposure AGC is aiming for
-	double shutter_time;
+	libcamera::utils::Duration total_exposure_value; // value for all exposure and gain for this image
+	libcamera::utils::Duration target_exposure_value; // (unfiltered) target total exposure AGC is aiming for
+	libcamera::utils::Duration shutter_time;
 	double analogue_gain;
 	char exposure_mode[32];
 	char constraint_mode[32];
 	char metering_mode[32];
 	double ev;
-	double flicker_period;
+	libcamera::utils::Duration flicker_period;
 	int floating_region_enable;
-	double fixed_shutter;
+	libcamera::utils::Duration fixed_shutter;
 	double fixed_analogue_gain;
 	double digital_gain;
 	int locked;
diff --git a/src/ipa/raspberrypi/controller/device_status.h b/src/ipa/raspberrypi/controller/device_status.h
index aa08608b..131b4cd3 100644
--- a/src/ipa/raspberrypi/controller/device_status.h
+++ b/src/ipa/raspberrypi/controller/device_status.h
@@ -6,6 +6,8 @@
  */
 #pragma once
 
+#include "libcamera/internal/utils.h"
+
 // Definition of "device metadata" which stores things like shutter time and
 // analogue gain that downstream control algorithms will want to know.
 
@@ -14,8 +16,8 @@ extern "C" {
 #endif
 
 struct DeviceStatus {
-	// time shutter is open, in microseconds
-	double shutter_speed;
+	// time shutter is open
+	libcamera::utils::Duration shutter_speed;
 	double analogue_gain;
 	// 1.0/distance-in-metres, or 0 if unknown
 	double lens_position;
diff --git a/src/ipa/raspberrypi/controller/rpi/agc.cpp b/src/ipa/raspberrypi/controller/rpi/agc.cpp
index fd3359a7..55e80ac7 100644
--- a/src/ipa/raspberrypi/controller/rpi/agc.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/agc.cpp
@@ -56,19 +56,26 @@ read_metering_modes(std::map<std::string, AgcMeteringMode> &metering_modes,
 	return first;
 }
 
-static int read_double_list(std::vector<double> &list,
-			    boost::property_tree::ptree const &params)
+static int read_list(std::vector<double> &list,
+		     boost::property_tree::ptree const &params)
 {
 	for (auto &p : params)
 		list.push_back(p.second.get_value<double>());
 	return list.size();
 }
 
+static int read_list(std::vector<Duration> &list,
+		     boost::property_tree::ptree const &params)
+{
+	for (auto &p : params)
+		list.push_back(p.second.get_value<double>() * 1us);
+	return list.size();
+}
+
 void AgcExposureMode::Read(boost::property_tree::ptree const &params)
 {
-	int num_shutters =
-		read_double_list(shutter, params.get_child("shutter"));
-	int num_ags = read_double_list(gain, params.get_child("gain"));
+	int num_shutters = read_list(shutter, params.get_child("shutter"));
+	int num_ags = read_list(gain, params.get_child("gain"));
 	if (num_shutters < 2 || num_ags < 2)
 		throw std::runtime_error(
 			"AgcConfig: must have at least two entries in exposure profile");
@@ -148,7 +155,7 @@ void AgcConfig::Read(boost::property_tree::ptree const &params)
 		params.get<double>("fast_reduce_threshold", 0.4);
 	base_ev = params.get<double>("base_ev", 1.0);
 	// Start with quite a low value as ramping up is easier than ramping down.
-	default_exposure_time = params.get<double>("default_exposure_time", 1000);
+	default_exposure_time = params.get<double>("default_exposure_time", 1000) * 1us;
 	default_analogue_gain = params.get<double>("default_analogue_gain", 1.0);
 }
 
@@ -156,9 +163,9 @@ Agc::Agc(Controller *controller)
 	: AgcAlgorithm(controller), metering_mode_(nullptr),
 	  exposure_mode_(nullptr), constraint_mode_(nullptr),
 	  frame_count_(0), lock_count_(0),
-	  last_target_exposure_(0.0),
-	  ev_(1.0), flicker_period_(0.0),
-	  max_shutter_(0), fixed_shutter_(0), fixed_analogue_gain_(0.0)
+	  last_target_exposure_(0s),
+	  ev_(1.0), flicker_period_(0s),
+	  max_shutter_(0s), fixed_shutter_(0s), fixed_analogue_gain_(0.0)
 {
 	memset(&awb_, 0, sizeof(awb_));
 	// Setting status_.total_exposure_value_ to zero initially tells us
@@ -204,7 +211,7 @@ void Agc::Pause()
 
 void Agc::Resume()
 {
-	fixed_shutter_ = 0;
+	fixed_shutter_ = 0s;
 	fixed_analogue_gain_ = 0;
 }
 
@@ -225,17 +232,17 @@ void Agc::SetEv(double ev)
 
 void Agc::SetFlickerPeriod(Duration flicker_period)
 {
-	flicker_period_ = flicker_period.get<std::micro>();
+	flicker_period_ = flicker_period;
 }
 
 void Agc::SetMaxShutter(Duration max_shutter)
 {
-	max_shutter_ = max_shutter.get<std::micro>();
+	max_shutter_ = max_shutter;
 }
 
 void Agc::SetFixedShutter(Duration fixed_shutter)
 {
-	fixed_shutter_ = fixed_shutter.get<std::micro>();
+	fixed_shutter_ = fixed_shutter;
 	// Set this in case someone calls Pause() straight after.
 	status_.shutter_time = clipShutter(fixed_shutter_);
 }
@@ -267,8 +274,8 @@ void Agc::SwitchMode([[maybe_unused]] CameraMode const &camera_mode,
 {
 	housekeepConfig();
 
-	double fixed_shutter = clipShutter(fixed_shutter_);
-	if (fixed_shutter != 0.0 && fixed_analogue_gain_ != 0.0) {
+	Duration fixed_shutter = clipShutter(fixed_shutter_);
+	if (fixed_shutter && fixed_analogue_gain_) {
 		// We're going to reset the algorithm here with these fixed values.
 
 		fetchAwbStatus(metadata);
@@ -313,8 +320,8 @@ void Agc::Prepare(Metadata *image_metadata)
 		// Process has run, so we have meaningful values.
 		DeviceStatus device_status;
 		if (image_metadata->Get("device.status", device_status) == 0) {
-			double actual_exposure = device_status.shutter_speed *
-						 device_status.analogue_gain;
+			Duration actual_exposure = device_status.shutter_speed *
+						   device_status.analogue_gain;
 			if (actual_exposure) {
 				status_.digital_gain =
 					status_.total_exposure_value /
@@ -327,7 +334,8 @@ void Agc::Prepare(Metadata *image_metadata)
 					std::min(status_.digital_gain, 4.0));
 				LOG(RPiAgc, Debug) << "Actual exposure " << actual_exposure;
 				LOG(RPiAgc, Debug) << "Use digital_gain " << status_.digital_gain;
-				LOG(RPiAgc, Debug) << "Effective exposure " << actual_exposure * status_.digital_gain;
+				LOG(RPiAgc, Debug) << "Effective exposure "
+						   << actual_exposure * status_.digital_gain;
 				// Decide whether AEC/AGC has converged.
 				updateLockStatus(device_status);
 			}
@@ -371,9 +379,9 @@ void Agc::updateLockStatus(DeviceStatus const &device_status)
 	const double RESET_MARGIN = 1.5;
 
 	// Add 200us to the exposure time error to allow for line quantisation.
-	double exposure_error = last_device_status_.shutter_speed * ERROR_FACTOR + 200;
+	Duration exposure_error = last_device_status_.shutter_speed * ERROR_FACTOR + 200us;
 	double gain_error = last_device_status_.analogue_gain * ERROR_FACTOR;
-	double target_error = last_target_exposure_ * ERROR_FACTOR;
+	Duration target_error = last_target_exposure_ * ERROR_FACTOR;
 
 	// Note that we don't know the exposure/gain limits of the sensor, so
 	// the values we keep requesting may be unachievable. For this reason
@@ -463,7 +471,7 @@ void Agc::fetchCurrentExposure(Metadata *image_metadata)
 	current_.analogue_gain = device_status->analogue_gain;
 	AgcStatus *agc_status =
 		image_metadata->GetLocked<AgcStatus>("agc.status");
-	current_.total_exposure = agc_status ? agc_status->total_exposure_value : 0;
+	current_.total_exposure = agc_status ? agc_status->total_exposure_value : 0s;
 	current_.total_exposure_no_dg = current_.shutter * current_.analogue_gain;
 }
 
@@ -574,7 +582,7 @@ void Agc::computeGain(bcm2835_isp_stats *statistics, Metadata *image_metadata,
 
 void Agc::computeTargetExposure(double gain)
 {
-	if (status_.fixed_shutter != 0.0 && status_.fixed_analogue_gain != 0.0) {
+	if (status_.fixed_shutter && status_.fixed_analogue_gain) {
 		// When ag and shutter are both fixed, we need to drive the
 		// total exposure so that we end up with a digital gain of at least
 		// 1/min_colour_gain. Otherwise we'd desaturate channels causing
@@ -589,11 +597,11 @@ void Agc::computeTargetExposure(double gain)
 		target_.total_exposure = current_.total_exposure_no_dg * gain;
 		// The final target exposure is also limited to what the exposure
 		// mode allows.
-		double max_shutter = status_.fixed_shutter != 0.0
+		Duration max_shutter = status_.fixed_shutter
 				   ? status_.fixed_shutter
 				   : exposure_mode_->shutter.back();
 		max_shutter = clipShutter(max_shutter);
-		double max_total_exposure =
+		Duration max_total_exposure =
 			max_shutter *
 			(status_.fixed_analogue_gain != 0.0
 				 ? status_.fixed_analogue_gain
@@ -638,7 +646,7 @@ void Agc::filterExposure(bool desaturate)
 	if ((status_.fixed_shutter && status_.fixed_analogue_gain) ||
 	    frame_count_ <= config_.startup_frames)
 		speed = 1.0;
-	if (filtered_.total_exposure == 0.0) {
+	if (!filtered_.total_exposure) {
 		filtered_.total_exposure = target_.total_exposure;
 		filtered_.total_exposure_no_dg = target_.total_exposure_no_dg;
 	} else {
@@ -675,9 +683,10 @@ void Agc::divideUpExposure()
 	// Sending the fixed shutter/gain cases through the same code may seem
 	// unnecessary, but it will make more sense when extend this to cover
 	// variable aperture.
-	double exposure_value = filtered_.total_exposure_no_dg;
-	double shutter_time, analogue_gain;
-	shutter_time = status_.fixed_shutter != 0.0
+	Duration exposure_value = filtered_.total_exposure_no_dg;
+	Duration shutter_time;
+	double analogue_gain;
+	shutter_time = status_.fixed_shutter
 			       ? status_.fixed_shutter
 			       : exposure_mode_->shutter[0];
 	shutter_time = clipShutter(shutter_time);
@@ -687,8 +696,8 @@ void Agc::divideUpExposure()
 	if (shutter_time * analogue_gain < exposure_value) {
 		for (unsigned int stage = 1;
 		     stage < exposure_mode_->gain.size(); stage++) {
-			if (status_.fixed_shutter == 0.0) {
-				double stage_shutter =
+			if (!status_.fixed_shutter) {
+				Duration stage_shutter =
 					clipShutter(exposure_mode_->shutter[stage]);
 				if (stage_shutter * analogue_gain >=
 				    exposure_value) {
@@ -714,12 +723,11 @@ void Agc::divideUpExposure()
 			   << analogue_gain;
 	// Finally adjust shutter time for flicker avoidance (require both
 	// shutter and gain not to be fixed).
-	if (status_.fixed_shutter == 0.0 &&
-	    status_.fixed_analogue_gain == 0.0 &&
-	    status_.flicker_period != 0.0) {
+	if (!status_.fixed_shutter && !status_.fixed_analogue_gain &&
+	    status_.flicker_period) {
 		int flicker_periods = shutter_time / status_.flicker_period;
-		if (flicker_periods > 0) {
-			double new_shutter_time = flicker_periods * status_.flicker_period;
+		if (flicker_periods) {
+			Duration new_shutter_time = flicker_periods * status_.flicker_period;
 			analogue_gain *= shutter_time / new_shutter_time;
 			// We should still not allow the ag to go over the
 			// largest value in the exposure mode. Note that this
@@ -739,7 +747,7 @@ void Agc::divideUpExposure()
 void Agc::writeAndFinish(Metadata *image_metadata, bool desaturate)
 {
 	status_.total_exposure_value = filtered_.total_exposure;
-	status_.target_exposure_value = desaturate ? 0 : target_.total_exposure_no_dg;
+	status_.target_exposure_value = desaturate ? 0s : target_.total_exposure_no_dg;
 	status_.shutter_time = filtered_.shutter;
 	status_.analogue_gain = filtered_.analogue_gain;
 	// Write to metadata as well, in case anyone wants to update the camera
@@ -751,7 +759,7 @@ void Agc::writeAndFinish(Metadata *image_metadata, bool desaturate)
 			   << " analogue gain " << filtered_.analogue_gain;
 }
 
-double Agc::clipShutter(double shutter)
+Duration Agc::clipShutter(Duration shutter)
 {
 	if (max_shutter_)
 		shutter = std::min(shutter, max_shutter_);
diff --git a/src/ipa/raspberrypi/controller/rpi/agc.hpp b/src/ipa/raspberrypi/controller/rpi/agc.hpp
index b52aaa23..75078948 100644
--- a/src/ipa/raspberrypi/controller/rpi/agc.hpp
+++ b/src/ipa/raspberrypi/controller/rpi/agc.hpp
@@ -9,6 +9,8 @@
 #include <vector>
 #include <mutex>
 
+#include "libcamera/internal/utils.h"
+
 #include "../agc_algorithm.hpp"
 #include "../agc_status.h"
 #include "../pwl.hpp"
@@ -22,13 +24,15 @@
 
 namespace RPiController {
 
+using namespace std::literals::chrono_literals;
+
 struct AgcMeteringMode {
 	double weights[AGC_STATS_SIZE];
 	void Read(boost::property_tree::ptree const &params);
 };
 
 struct AgcExposureMode {
-	std::vector<double> shutter;
+	std::vector<libcamera::utils::Duration> shutter;
 	std::vector<double> gain;
 	void Read(boost::property_tree::ptree const &params);
 };
@@ -61,7 +65,7 @@ struct AgcConfig {
 	std::string default_exposure_mode;
 	std::string default_constraint_mode;
 	double base_ev;
-	double default_exposure_time;
+	libcamera::utils::Duration default_exposure_time;
 	double default_analogue_gain;
 };
 
@@ -101,19 +105,19 @@ private:
 	void filterExposure(bool desaturate);
 	void divideUpExposure();
 	void writeAndFinish(Metadata *image_metadata, bool desaturate);
-	double clipShutter(double shutter);
+	libcamera::utils::Duration clipShutter(libcamera::utils::Duration shutter);
 	AgcMeteringMode *metering_mode_;
 	AgcExposureMode *exposure_mode_;
 	AgcConstraintMode *constraint_mode_;
 	uint64_t frame_count_;
 	AwbStatus awb_;
 	struct ExposureValues {
-		ExposureValues() : shutter(0), analogue_gain(0),
-				   total_exposure(0), total_exposure_no_dg(0) {}
-		double shutter;
+		ExposureValues() : shutter(0s), analogue_gain(0),
+				   total_exposure(0s), total_exposure_no_dg(0s) {}
+		libcamera::utils::Duration shutter;
 		double analogue_gain;
-		double total_exposure;
-		double total_exposure_no_dg; // without digital gain
+		libcamera::utils::Duration total_exposure;
+		libcamera::utils::Duration total_exposure_no_dg; // without digital gain
 	};
 	ExposureValues current_;  // values for the current frame
 	ExposureValues target_;   // calculate the values we want here
@@ -121,15 +125,15 @@ private:
 	AgcStatus status_;
 	int lock_count_;
 	DeviceStatus last_device_status_;
-	double last_target_exposure_;
+	libcamera::utils::Duration last_target_exposure_;
 	// Below here the "settings" that applications can change.
 	std::string metering_mode_name_;
 	std::string exposure_mode_name_;
 	std::string constraint_mode_name_;
 	double ev_;
-	double flicker_period_;
-	double max_shutter_;
-	double fixed_shutter_;
+	libcamera::utils::Duration flicker_period_;
+	libcamera::utils::Duration max_shutter_;
+	libcamera::utils::Duration fixed_shutter_;
 	double fixed_analogue_gain_;
 };
 
diff --git a/src/ipa/raspberrypi/controller/rpi/lux.cpp b/src/ipa/raspberrypi/controller/rpi/lux.cpp
index f74381ca..258e44f4 100644
--- a/src/ipa/raspberrypi/controller/rpi/lux.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/lux.cpp
@@ -16,6 +16,7 @@
 
 using namespace RPiController;
 using namespace libcamera;
+using namespace std::literals::chrono_literals;
 
 LOG_DEFINE_CATEGORY(RPiLux)
 
@@ -38,7 +39,7 @@ char const *Lux::Name() const
 void Lux::Read(boost::property_tree::ptree const &params)
 {
 	reference_shutter_speed_ =
-		params.get<double>("reference_shutter_speed");
+		params.get<double>("reference_shutter_speed") * 1.0us;
 	reference_gain_ = params.get<double>("reference_gain");
 	reference_aperture_ = params.get<double>("reference_aperture", 1.0);
 	reference_Y_ = params.get<double>("reference_Y");
@@ -60,15 +61,15 @@ void Lux::Prepare(Metadata *image_metadata)
 void Lux::Process(StatisticsPtr &stats, Metadata *image_metadata)
 {
 	// set some initial values to shut the compiler up
-	DeviceStatus device_status =
-		{ .shutter_speed = 1.0,
-		  .analogue_gain = 1.0,
-		  .lens_position = 0.0,
-		  .aperture = 0.0,
-		  .flash_intensity = 0.0 };
+	DeviceStatus device_status = {
+		.shutter_speed = 1.0ms,
+		.analogue_gain = 1.0,
+		.lens_position = 0.0,
+		.aperture = 0.0,
+		.flash_intensity = 0.0
+	};
 	if (image_metadata->Get("device.status", device_status) == 0) {
 		double current_gain = device_status.analogue_gain;
-		double current_shutter_speed = device_status.shutter_speed;
 		double current_aperture = device_status.aperture;
 		if (current_aperture == 0)
 			current_aperture = current_aperture_;
@@ -83,7 +84,7 @@ void Lux::Process(StatisticsPtr &stats, Metadata *image_metadata)
 		double current_Y = sum / (double)num + .5;
 		double gain_ratio = reference_gain_ / current_gain;
 		double shutter_speed_ratio =
-			reference_shutter_speed_ / current_shutter_speed;
+			reference_shutter_speed_ / device_status.shutter_speed;
 		double aperture_ratio = reference_aperture_ / current_aperture;
 		double Y_ratio = current_Y * (65536 / num_bins) / reference_Y_;
 		double estimated_lux = shutter_speed_ratio * gain_ratio *
diff --git a/src/ipa/raspberrypi/controller/rpi/lux.hpp b/src/ipa/raspberrypi/controller/rpi/lux.hpp
index f9090484..45c84439 100644
--- a/src/ipa/raspberrypi/controller/rpi/lux.hpp
+++ b/src/ipa/raspberrypi/controller/rpi/lux.hpp
@@ -8,6 +8,8 @@
 
 #include <mutex>
 
+#include "libcamera/internal/utils.h"
+
 #include "../lux_status.h"
 #include "../algorithm.hpp"
 
@@ -28,7 +30,7 @@ public:
 private:
 	// These values define the conditions of the reference image, against
 	// which we compare the new image.
-	double reference_shutter_speed_; // in micro-seconds
+	libcamera::utils::Duration reference_shutter_speed_;
 	double reference_gain_;
 	double reference_aperture_; // units of 1/f
 	double reference_Y_; // out of 65536