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+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi (Trading) Limited
+ *
+ * agc.cpp - AGC/AEC control algorithm
+ */
+
+#include <map>
+
+#include "linux/bcm2835-isp.h"
+
+#include "../awb_status.h"
+#include "../device_status.h"
+#include "../histogram.hpp"
+#include "../logging.hpp"
+#include "../lux_status.h"
+#include "../metadata.hpp"
+
+#include "agc.hpp"
+
+using namespace RPi;
+
+#define NAME "rpi.agc"
+
+#define PIPELINE_BITS 13 // seems to be a 13-bit pipeline
+
+void AgcMeteringMode::Read(boost::property_tree::ptree const &params)
+{
+ int num = 0;
+ for (auto &p : params.get_child("weights")) {
+ if (num == AGC_STATS_SIZE)
+ throw std::runtime_error("AgcConfig: too many weights");
+ weights[num++] = p.second.get_value<double>();
+ }
+ if (num != AGC_STATS_SIZE)
+ throw std::runtime_error("AgcConfig: insufficient weights");
+}
+
+static std::string
+read_metering_modes(std::map<std::string, AgcMeteringMode> &metering_modes,
+ boost::property_tree::ptree const &params)
+{
+ std::string first;
+ for (auto &p : params) {
+ AgcMeteringMode metering_mode;
+ metering_mode.Read(p.second);
+ metering_modes[p.first] = std::move(metering_mode);
+ if (first.empty())
+ first = p.first;
+ }
+ return first;
+}
+
+static int read_double_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();
+}
+
+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"));
+ if (num_shutters < 2 || num_ags < 2)
+ throw std::runtime_error(
+ "AgcConfig: must have at least two entries in exposure profile");
+ if (num_shutters != num_ags)
+ throw std::runtime_error(
+ "AgcConfig: expect same number of exposure and gain entries in exposure profile");
+}
+
+static std::string
+read_exposure_modes(std::map<std::string, AgcExposureMode> &exposure_modes,
+ boost::property_tree::ptree const &params)
+{
+ std::string first;
+ for (auto &p : params) {
+ AgcExposureMode exposure_mode;
+ exposure_mode.Read(p.second);
+ exposure_modes[p.first] = std::move(exposure_mode);
+ if (first.empty())
+ first = p.first;
+ }
+ return first;
+}
+
+void AgcConstraint::Read(boost::property_tree::ptree const &params)
+{
+ std::string bound_string = params.get<std::string>("bound", "");
+ transform(bound_string.begin(), bound_string.end(),
+ bound_string.begin(), ::toupper);
+ if (bound_string != "UPPER" && bound_string != "LOWER")
+ throw std::runtime_error(
+ "AGC constraint type should be UPPER or LOWER");
+ bound = bound_string == "UPPER" ? Bound::UPPER : Bound::LOWER;
+ q_lo = params.get<double>("q_lo");
+ q_hi = params.get<double>("q_hi");
+ Y_target.Read(params.get_child("y_target"));
+}
+
+static AgcConstraintMode
+read_constraint_mode(boost::property_tree::ptree const &params)
+{
+ AgcConstraintMode mode;
+ for (auto &p : params) {
+ AgcConstraint constraint;
+ constraint.Read(p.second);
+ mode.push_back(std::move(constraint));
+ }
+ return mode;
+}
+
+static std::string read_constraint_modes(
+ std::map<std::string, AgcConstraintMode> &constraint_modes,
+ boost::property_tree::ptree const &params)
+{
+ std::string first;
+ for (auto &p : params) {
+ constraint_modes[p.first] = read_constraint_mode(p.second);
+ if (first.empty())
+ first = p.first;
+ }
+ return first;
+}
+
+void AgcConfig::Read(boost::property_tree::ptree const &params)
+{
+ RPI_LOG("AgcConfig");
+ default_metering_mode = read_metering_modes(
+ metering_modes, params.get_child("metering_modes"));
+ default_exposure_mode = read_exposure_modes(
+ exposure_modes, params.get_child("exposure_modes"));
+ default_constraint_mode = read_constraint_modes(
+ constraint_modes, params.get_child("constraint_modes"));
+ Y_target.Read(params.get_child("y_target"));
+ speed = params.get<double>("speed", 0.2);
+ startup_frames = params.get<uint16_t>("startup_frames", 10);
+ fast_reduce_threshold =
+ params.get<double>("fast_reduce_threshold", 0.4);
+ base_ev = params.get<double>("base_ev", 1.0);
+}
+
+Agc::Agc(Controller *controller)
+ : AgcAlgorithm(controller), metering_mode_(nullptr),
+ exposure_mode_(nullptr), constraint_mode_(nullptr),
+ frame_count_(0), lock_count_(0)
+{
+ ev_ = status_.ev = 1.0;
+ flicker_period_ = status_.flicker_period = 0.0;
+ fixed_shutter_ = status_.fixed_shutter = 0;
+ fixed_analogue_gain_ = status_.fixed_analogue_gain = 0.0;
+ // set to zero initially, so we can tell it's not been calculated
+ status_.total_exposure_value = 0.0;
+ status_.target_exposure_value = 0.0;
+ status_.locked = false;
+ output_status_ = status_;
+}
+
+char const *Agc::Name() const
+{
+ return NAME;
+}
+
+void Agc::Read(boost::property_tree::ptree const &params)
+{
+ RPI_LOG("Agc");
+ config_.Read(params);
+ // Set the config's defaults (which are the first ones it read) as our
+ // current modes, until someone changes them. (they're all known to
+ // exist at this point)
+ metering_mode_name_ = config_.default_metering_mode;
+ metering_mode_ = &config_.metering_modes[metering_mode_name_];
+ exposure_mode_name_ = config_.default_exposure_mode;
+ exposure_mode_ = &config_.exposure_modes[exposure_mode_name_];
+ constraint_mode_name_ = config_.default_constraint_mode;
+ constraint_mode_ = &config_.constraint_modes[constraint_mode_name_];
+}
+
+void Agc::SetEv(double ev)
+{
+ std::unique_lock<std::mutex> lock(settings_mutex_);
+ ev_ = ev;
+}
+
+void Agc::SetFlickerPeriod(double flicker_period)
+{
+ std::unique_lock<std::mutex> lock(settings_mutex_);
+ flicker_period_ = flicker_period;
+}
+
+void Agc::SetFixedShutter(double fixed_shutter)
+{
+ std::unique_lock<std::mutex> lock(settings_mutex_);
+ fixed_shutter_ = fixed_shutter;
+}
+
+void Agc::SetFixedAnalogueGain(double fixed_analogue_gain)
+{
+ std::unique_lock<std::mutex> lock(settings_mutex_);
+ fixed_analogue_gain_ = fixed_analogue_gain;
+}
+
+void Agc::SetMeteringMode(std::string const &metering_mode_name)
+{
+ std::unique_lock<std::mutex> lock(settings_mutex_);
+ metering_mode_name_ = metering_mode_name;
+}
+
+void Agc::SetExposureMode(std::string const &exposure_mode_name)
+{
+ std::unique_lock<std::mutex> lock(settings_mutex_);
+ exposure_mode_name_ = exposure_mode_name;
+}
+
+void Agc::SetConstraintMode(std::string const &constraint_mode_name)
+{
+ std::unique_lock<std::mutex> lock(settings_mutex_);
+ constraint_mode_name_ = constraint_mode_name;
+}
+
+void Agc::Prepare(Metadata *image_metadata)
+{
+ AgcStatus status;
+ {
+ std::unique_lock<std::mutex> lock(output_mutex_);
+ status = output_status_;
+ }
+ int lock_count = lock_count_;
+ lock_count_ = 0;
+ status.digital_gain = 1.0;
+ if (status_.total_exposure_value) {
+ // 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;
+ if (actual_exposure) {
+ status.digital_gain =
+ status_.total_exposure_value /
+ actual_exposure;
+ RPI_LOG("Want total exposure " << status_.total_exposure_value);
+ // Never ask for a gain < 1.0, and also impose
+ // some upper limit. Make it customisable?
+ status.digital_gain = std::max(
+ 1.0,
+ std::min(status.digital_gain, 4.0));
+ RPI_LOG("Actual exposure " << actual_exposure);
+ RPI_LOG("Use digital_gain " << status.digital_gain);
+ RPI_LOG("Effective exposure " << actual_exposure * status.digital_gain);
+ // Decide whether AEC/AGC has converged.
+ // Insist AGC is steady for MAX_LOCK_COUNT
+ // frames before we say we are "locked".
+ // (The hard-coded constants may need to
+ // become customisable.)
+ if (status.target_exposure_value) {
+#define MAX_LOCK_COUNT 3
+ double err = 0.10 * status.target_exposure_value + 200;
+ if (actual_exposure <
+ status.target_exposure_value + err
+ && actual_exposure >
+ status.target_exposure_value - err)
+ lock_count_ =
+ std::min(lock_count + 1,
+ MAX_LOCK_COUNT);
+ else if (actual_exposure <
+ status.target_exposure_value
+ + 1.5 * err &&
+ actual_exposure >
+ status.target_exposure_value
+ - 1.5 * err)
+ lock_count_ = lock_count;
+ RPI_LOG("Lock count: " << lock_count_);
+ }
+ }
+ } else
+ RPI_LOG(Name() << ": no device metadata");
+ status.locked = lock_count_ >= MAX_LOCK_COUNT;
+ //printf("%s\n", status.locked ? "+++++++++" : "-");
+ image_metadata->Set("agc.status", status);
+ }
+}
+
+void Agc::Process(StatisticsPtr &stats, Metadata *image_metadata)
+{
+ frame_count_++;
+ // First a little bit of housekeeping, fetching up-to-date settings and
+ // configuration, that kind of thing.
+ housekeepConfig();
+ // Get the current exposure values for the frame that's just arrived.
+ fetchCurrentExposure(image_metadata);
+ // Compute the total gain we require relative to the current exposure.
+ double gain, target_Y;
+ computeGain(stats.get(), image_metadata, gain, target_Y);
+ // Now compute the target (final) exposure which we think we want.
+ computeTargetExposure(gain);
+ // Some of the exposure has to be applied as digital gain, so work out
+ // what that is. This function also tells us whether it's decided to
+ // "desaturate" the image more quickly.
+ bool desaturate = applyDigitalGain(image_metadata, gain, target_Y);
+ // The results have to be filtered so as not to change too rapidly.
+ filterExposure(desaturate);
+ // The last thing is to divvy up the exposure value into a shutter time
+ // and analogue_gain, according to the current exposure mode.
+ divvyupExposure();
+ // Finally advertise what we've done.
+ writeAndFinish(image_metadata, desaturate);
+}
+
+static void copy_string(std::string const &s, char *d, size_t size)
+{
+ size_t length = s.copy(d, size - 1);
+ d[length] = '\0';
+}
+
+void Agc::housekeepConfig()
+{
+ // First fetch all the up-to-date settings, so no one else has to do it.
+ std::string new_exposure_mode_name, new_constraint_mode_name,
+ new_metering_mode_name;
+ {
+ std::unique_lock<std::mutex> lock(settings_mutex_);
+ new_metering_mode_name = metering_mode_name_;
+ new_exposure_mode_name = exposure_mode_name_;
+ new_constraint_mode_name = constraint_mode_name_;
+ status_.ev = ev_;
+ status_.fixed_shutter = fixed_shutter_;
+ status_.fixed_analogue_gain = fixed_analogue_gain_;
+ status_.flicker_period = flicker_period_;
+ }
+ RPI_LOG("ev " << status_.ev << " fixed_shutter "
+ << status_.fixed_shutter << " fixed_analogue_gain "
+ << status_.fixed_analogue_gain);
+ // Make sure the "mode" pointers point to the up-to-date things, if
+ // they've changed.
+ if (strcmp(new_metering_mode_name.c_str(), status_.metering_mode)) {
+ auto it = config_.metering_modes.find(new_metering_mode_name);
+ if (it == config_.metering_modes.end())
+ throw std::runtime_error("Agc: no metering mode " +
+ new_metering_mode_name);
+ metering_mode_ = &it->second;
+ copy_string(new_metering_mode_name, status_.metering_mode,
+ sizeof(status_.metering_mode));
+ }
+ if (strcmp(new_exposure_mode_name.c_str(), status_.exposure_mode)) {
+ auto it = config_.exposure_modes.find(new_exposure_mode_name);
+ if (it == config_.exposure_modes.end())
+ throw std::runtime_error("Agc: no exposure profile " +
+ new_exposure_mode_name);
+ exposure_mode_ = &it->second;
+ copy_string(new_exposure_mode_name, status_.exposure_mode,
+ sizeof(status_.exposure_mode));
+ }
+ if (strcmp(new_constraint_mode_name.c_str(), status_.constraint_mode)) {
+ auto it =
+ config_.constraint_modes.find(new_constraint_mode_name);
+ if (it == config_.constraint_modes.end())
+ throw std::runtime_error("Agc: no constraint list " +
+ new_constraint_mode_name);
+ constraint_mode_ = &it->second;
+ copy_string(new_constraint_mode_name, status_.constraint_mode,
+ sizeof(status_.constraint_mode));
+ }
+ RPI_LOG("exposure_mode "
+ << new_exposure_mode_name << " constraint_mode "
+ << new_constraint_mode_name << " metering_mode "
+ << new_metering_mode_name);
+}
+
+void Agc::fetchCurrentExposure(Metadata *image_metadata)
+{
+ std::unique_lock<Metadata> lock(*image_metadata);
+ DeviceStatus *device_status =
+ image_metadata->GetLocked<DeviceStatus>("device.status");
+ if (!device_status)
+ throw std::runtime_error("Agc: no device metadata");
+ current_.shutter = device_status->shutter_speed;
+ 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_no_dg = current_.shutter * current_.analogue_gain;
+}
+
+static double compute_initial_Y(bcm2835_isp_stats *stats, Metadata *image_metadata,
+ double weights[])
+{
+ bcm2835_isp_stats_region *regions = stats->agc_stats;
+ struct AwbStatus awb;
+ awb.gain_r = awb.gain_g = awb.gain_b = 1.0; // in case no metadata
+ if (image_metadata->Get("awb.status", awb) != 0)
+ RPI_WARN("Agc: no AWB status found");
+ double Y_sum = 0, weight_sum = 0;
+ for (int i = 0; i < AGC_STATS_SIZE; i++) {
+ if (regions[i].counted == 0)
+ continue;
+ weight_sum += weights[i];
+ double Y = regions[i].r_sum * awb.gain_r * .299 +
+ regions[i].g_sum * awb.gain_g * .587 +
+ regions[i].b_sum * awb.gain_b * .114;
+ Y /= regions[i].counted;
+ Y_sum += Y * weights[i];
+ }
+ return Y_sum / weight_sum / (1 << PIPELINE_BITS);
+}
+
+// We handle extra gain through EV by adjusting our Y targets. However, you
+// simply can't monitor histograms once they get very close to (or beyond!)
+// saturation, so we clamp the Y targets to this value. It does mean that EV
+// increases don't necessarily do quite what you might expect in certain
+// (contrived) cases.
+
+#define EV_GAIN_Y_TARGET_LIMIT 0.9
+
+static double constraint_compute_gain(AgcConstraint &c, Histogram &h,
+ double lux, double ev_gain,
+ double &target_Y)
+{
+ target_Y = c.Y_target.Eval(c.Y_target.Domain().Clip(lux));
+ target_Y = std::min(EV_GAIN_Y_TARGET_LIMIT, target_Y * ev_gain);
+ double iqm = h.InterQuantileMean(c.q_lo, c.q_hi);
+ return (target_Y * NUM_HISTOGRAM_BINS) / iqm;
+}
+
+void Agc::computeGain(bcm2835_isp_stats *statistics, Metadata *image_metadata,
+ double &gain, double &target_Y)
+{
+ struct LuxStatus lux = {};
+ lux.lux = 400; // default lux level to 400 in case no metadata found
+ if (image_metadata->Get("lux.status", lux) != 0)
+ RPI_WARN("Agc: no lux level found");
+ Histogram h(statistics->hist[0].g_hist, NUM_HISTOGRAM_BINS);
+ double ev_gain = status_.ev * config_.base_ev;
+ // The initial gain and target_Y come from some of the regions. After
+ // that we consider the histogram constraints.
+ target_Y =
+ config_.Y_target.Eval(config_.Y_target.Domain().Clip(lux.lux));
+ target_Y = std::min(EV_GAIN_Y_TARGET_LIMIT, target_Y * ev_gain);
+ double initial_Y = compute_initial_Y(statistics, image_metadata,
+ metering_mode_->weights);
+ gain = std::min(10.0, target_Y / (initial_Y + .001));
+ RPI_LOG("Initially Y " << initial_Y << " target " << target_Y
+ << " gives gain " << gain);
+ for (auto &c : *constraint_mode_) {
+ double new_target_Y;
+ double new_gain =
+ constraint_compute_gain(c, h, lux.lux, ev_gain,
+ new_target_Y);
+ RPI_LOG("Constraint has target_Y "
+ << new_target_Y << " giving gain " << new_gain);
+ if (c.bound == AgcConstraint::Bound::LOWER &&
+ new_gain > gain) {
+ RPI_LOG("Lower bound constraint adopted");
+ gain = new_gain, target_Y = new_target_Y;
+ } else if (c.bound == AgcConstraint::Bound::UPPER &&
+ new_gain < gain) {
+ RPI_LOG("Upper bound constraint adopted");
+ gain = new_gain, target_Y = new_target_Y;
+ }
+ }
+ RPI_LOG("Final gain " << gain << " (target_Y " << target_Y << " ev "
+ << status_.ev << " base_ev " << config_.base_ev
+ << ")");
+}
+
+void Agc::computeTargetExposure(double gain)
+{
+ // The statistics reflect the image without digital gain, so the final
+ // total exposure we're aiming for is:
+ target_.total_exposure = current_.total_exposure_no_dg * gain;
+ // The final target exposure is also limited to what the exposure
+ // mode allows.
+ double max_total_exposure =
+ (status_.fixed_shutter != 0.0
+ ? status_.fixed_shutter
+ : exposure_mode_->shutter.back()) *
+ (status_.fixed_analogue_gain != 0.0
+ ? status_.fixed_analogue_gain
+ : exposure_mode_->gain.back());
+ target_.total_exposure = std::min(target_.total_exposure,
+ max_total_exposure);
+ RPI_LOG("Target total_exposure " << target_.total_exposure);
+}
+
+bool Agc::applyDigitalGain(Metadata *image_metadata, double gain,
+ double target_Y)
+{
+ double dg = 1.0;
+ // I think this pipeline subtracts black level and rescales before we
+ // get the stats, so no need to worry about it.
+ struct AwbStatus awb;
+ if (image_metadata->Get("awb.status", awb) == 0) {
+ double min_gain = std::min(awb.gain_r,
+ std::min(awb.gain_g, awb.gain_b));
+ dg *= std::max(1.0, 1.0 / min_gain);
+ } else
+ RPI_WARN("Agc: no AWB status found");
+ RPI_LOG("after AWB, target dg " << dg << " gain " << gain
+ << " target_Y " << target_Y);
+ // Finally, if we're trying to reduce exposure but the target_Y is
+ // "close" to 1.0, then the gain computed for that constraint will be
+ // only slightly less than one, because the measured Y can never be
+ // larger than 1.0. When this happens, demand a large digital gain so
+ // that the exposure can be reduced, de-saturating the image much more
+ // quickly (and we then approach the correct value more quickly from
+ // below).
+ bool desaturate = target_Y > config_.fast_reduce_threshold &&
+ gain < sqrt(target_Y);
+ if (desaturate)
+ dg /= config_.fast_reduce_threshold;
+ RPI_LOG("Digital gain " << dg << " desaturate? " << desaturate);
+ target_.total_exposure_no_dg = target_.total_exposure / dg;
+ RPI_LOG("Target total_exposure_no_dg " << target_.total_exposure_no_dg);
+ return desaturate;
+}
+
+void Agc::filterExposure(bool desaturate)
+{
+ double speed = frame_count_ <= config_.startup_frames ? 1.0 : config_.speed;
+ if (filtered_.total_exposure == 0.0) {
+ filtered_.total_exposure = target_.total_exposure;
+ filtered_.total_exposure_no_dg = target_.total_exposure_no_dg;
+ } else {
+ // If close to the result go faster, to save making so many
+ // micro-adjustments on the way. (Make this customisable?)
+ if (filtered_.total_exposure < 1.2 * target_.total_exposure &&
+ filtered_.total_exposure > 0.8 * target_.total_exposure)
+ speed = sqrt(speed);
+ filtered_.total_exposure = speed * target_.total_exposure +
+ filtered_.total_exposure * (1.0 - speed);
+ // When desaturing, take a big jump down in exposure_no_dg,
+ // which we'll hide with digital gain.
+ if (desaturate)
+ filtered_.total_exposure_no_dg =
+ target_.total_exposure_no_dg;
+ else
+ filtered_.total_exposure_no_dg =
+ speed * target_.total_exposure_no_dg +
+ filtered_.total_exposure_no_dg * (1.0 - speed);
+ }
+ // We can't let the no_dg exposure deviate too far below the
+ // total exposure, as there might not be enough digital gain available
+ // in the ISP to hide it (which will cause nasty oscillation).
+ if (filtered_.total_exposure_no_dg <
+ filtered_.total_exposure * config_.fast_reduce_threshold)
+ filtered_.total_exposure_no_dg = filtered_.total_exposure *
+ config_.fast_reduce_threshold;
+ RPI_LOG("After filtering, total_exposure " << filtered_.total_exposure <<
+ " no dg " << filtered_.total_exposure_no_dg);
+}
+
+void Agc::divvyupExposure()
+{
+ // 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
+ ? status_.fixed_shutter
+ : exposure_mode_->shutter[0];
+ analogue_gain = status_.fixed_analogue_gain != 0.0
+ ? status_.fixed_analogue_gain
+ : exposure_mode_->gain[0];
+ if (shutter_time * analogue_gain < exposure_value) {
+ for (unsigned int stage = 1;
+ stage < exposure_mode_->gain.size(); stage++) {
+ if (status_.fixed_shutter == 0.0) {
+ if (exposure_mode_->shutter[stage] *
+ analogue_gain >=
+ exposure_value) {
+ shutter_time =
+ exposure_value / analogue_gain;
+ break;
+ }
+ shutter_time = exposure_mode_->shutter[stage];
+ }
+ if (status_.fixed_analogue_gain == 0.0) {
+ if (exposure_mode_->gain[stage] *
+ shutter_time >=
+ exposure_value) {
+ analogue_gain =
+ exposure_value / shutter_time;
+ break;
+ }
+ analogue_gain = exposure_mode_->gain[stage];
+ }
+ }
+ }
+ RPI_LOG("Divided up shutter and gain are " << shutter_time << " and "
+ << 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) {
+ int flicker_periods = shutter_time / status_.flicker_period;
+ if (flicker_periods > 0) {
+ double 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
+ // may force more of the total exposure into the digital
+ // gain as a side-effect.
+ analogue_gain = std::min(analogue_gain,
+ exposure_mode_->gain.back());
+ shutter_time = new_shutter_time;
+ }
+ RPI_LOG("After flicker avoidance, shutter "
+ << shutter_time << " gain " << analogue_gain);
+ }
+ filtered_.shutter = shutter_time;
+ filtered_.analogue_gain = analogue_gain;
+}
+
+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_.shutter_time = filtered_.shutter;
+ status_.analogue_gain = filtered_.analogue_gain;
+ {
+ std::unique_lock<std::mutex> lock(output_mutex_);
+ output_status_ = status_;
+ }
+ // Write to metadata as well, in case anyone wants to update the camera
+ // immediately.
+ image_metadata->Set("agc.status", status_);
+ RPI_LOG("Output written, total exposure requested is "
+ << filtered_.total_exposure);
+ RPI_LOG("Camera exposure update: shutter time " << filtered_.shutter <<
+ " analogue gain " << filtered_.analogue_gain);
+}
+
+// Register algorithm with the system.
+static Algorithm *Create(Controller *controller)
+{
+ return (Algorithm *)new Agc(controller);
+}
+static RegisterAlgorithm reg(NAME, &Create);