From 7127954aaa5fe9938743cbc41a328027697aba8a Mon Sep 17 00:00:00 2001 From: David Plowman Date: Fri, 15 Sep 2023 16:58:44 +0100 Subject: ipa: rpi: agc: Use channel constraints in the AGC algorithm Whenever we run Agc::process(), we store the most recent total exposure requested for each channel. With these values we can apply the channel constraints after time-filtering the requested total exposure, but before working out how much digital gain is needed. Signed-off-by: David Plowman Reviewed-by: Naushir Patuck Reviewed-by: Jacopo Mondi Signed-off-by: Jacopo Mondi --- src/ipa/rpi/controller/rpi/agc.cpp | 22 +++++++++--- src/ipa/rpi/controller/rpi/agc.h | 1 + src/ipa/rpi/controller/rpi/agc_channel.cpp | 58 ++++++++++++++++++++++++++---- src/ipa/rpi/controller/rpi/agc_channel.h | 8 +++-- 4 files changed, 75 insertions(+), 14 deletions(-) diff --git a/src/ipa/rpi/controller/rpi/agc.cpp b/src/ipa/rpi/controller/rpi/agc.cpp index 8b9d2026..870cb431 100644 --- a/src/ipa/rpi/controller/rpi/agc.cpp +++ b/src/ipa/rpi/controller/rpi/agc.cpp @@ -39,6 +39,7 @@ int Agc::read(const libcamera::YamlObject ¶ms) */ if (!params.contains("channels")) { LOG(RPiAgc, Debug) << "Single channel only"; + channelTotalExposures_.resize(1, 0s); channelData_.emplace_back(); return channelData_.back().channel.read(params, getHardwareConfig()); } @@ -58,6 +59,8 @@ int Agc::read(const libcamera::YamlObject ¶ms) return -1; } + channelTotalExposures_.resize(channelData_.size(), 0s); + return 0; } @@ -236,16 +239,22 @@ static void getDelayedChannelIndex(Metadata *metadata, const char *message, unsi } } -static void setCurrentChannelIndex(Metadata *metadata, const char *message, unsigned int channelIndex) +static libcamera::utils::Duration +setCurrentChannelIndexGetExposure(Metadata *metadata, const char *message, unsigned int channelIndex) { std::unique_lock lock(*metadata); AgcStatus *status = metadata->getLocked("agc.status"); - if (status) + libcamera::utils::Duration dur = 0s; + + if (status) { status->channel = channelIndex; - else { + dur = status->totalExposureValue; + } else { /* This does happen at startup, otherwise it would be a Warning or Error. */ LOG(RPiAgc, Debug) << message; } + + return dur; } void Agc::prepare(Metadata *imageMetadata) @@ -310,8 +319,11 @@ void Agc::process(StatisticsPtr &stats, Metadata *imageMetadata) LOG(RPiAgc, Debug) << "process: channel " << channelIndex << " not seen yet"; } - channelData.channel.process(stats, deviceStatus, imageMetadata); - setCurrentChannelIndex(imageMetadata, "process: no AGC status found", channelIndex); + channelData.channel.process(stats, deviceStatus, imageMetadata, channelTotalExposures_); + auto dur = setCurrentChannelIndexGetExposure(imageMetadata, "process: no AGC status found", + channelIndex); + if (dur) + channelTotalExposures_[channelIndex] = dur; /* And onto the next channel for the next call. */ index_ = (index_ + 1) % activeChannels_.size(); diff --git a/src/ipa/rpi/controller/rpi/agc.h b/src/ipa/rpi/controller/rpi/agc.h index ee85c693..90890439 100644 --- a/src/ipa/rpi/controller/rpi/agc.h +++ b/src/ipa/rpi/controller/rpi/agc.h @@ -55,6 +55,7 @@ private: std::vector channelData_; std::vector activeChannels_; unsigned int index_; /* index into the activeChannels_ */ + AgcChannelTotalExposures channelTotalExposures_; }; } /* namespace RPiController */ diff --git a/src/ipa/rpi/controller/rpi/agc_channel.cpp b/src/ipa/rpi/controller/rpi/agc_channel.cpp index dfe363ff..3957dbc3 100644 --- a/src/ipa/rpi/controller/rpi/agc_channel.cpp +++ b/src/ipa/rpi/controller/rpi/agc_channel.cpp @@ -493,7 +493,9 @@ void AgcChannel::prepare(Metadata *imageMetadata) } } -void AgcChannel::process(StatisticsPtr &stats, DeviceStatus const &deviceStatus, Metadata *imageMetadata) +void AgcChannel::process(StatisticsPtr &stats, DeviceStatus const &deviceStatus, + Metadata *imageMetadata, + const AgcChannelTotalExposures &channelTotalExposures) { frameCount_++; /* @@ -512,12 +514,17 @@ void AgcChannel::process(StatisticsPtr &stats, DeviceStatus const &deviceStatus, computeTargetExposure(gain); /* The results have to be filtered so as not to change too rapidly. */ filterExposure(); + /* + * We may be asked to limit the exposure using other channels. If another channel + * determines our upper bound we may want to know this later. + */ + bool channelBound = applyChannelConstraints(channelTotalExposures); /* * 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. + * what that is. It also tells us whether it's trying to desaturate the image + * more quickly, which can only happen when another channel is not limiting us. */ - bool desaturate = applyDigitalGain(gain, targetY); + bool desaturate = applyDigitalGain(gain, targetY, channelBound); /* * The last thing is to divide up the exposure value into a shutter time * and analogue gain, according to the current exposure mode. @@ -794,7 +801,44 @@ void AgcChannel::computeTargetExposure(double gain) LOG(RPiAgc, Debug) << "Target totalExposure " << target_.totalExposure; } -bool AgcChannel::applyDigitalGain(double gain, double targetY) +bool AgcChannel::applyChannelConstraints(const AgcChannelTotalExposures &channelTotalExposures) +{ + bool channelBound = false; + LOG(RPiAgc, Debug) + << "Total exposure before channel constraints " << filtered_.totalExposure; + + for (const auto &constraint : config_.channelConstraints) { + LOG(RPiAgc, Debug) + << "Check constraint: channel " << constraint.channel << " bound " + << (constraint.bound == AgcChannelConstraint::Bound::UPPER ? "UPPER" : "LOWER") + << " factor " << constraint.factor; + if (constraint.channel >= channelTotalExposures.size() || + !channelTotalExposures[constraint.channel]) { + LOG(RPiAgc, Debug) << "no such channel or no exposure available- skipped"; + continue; + } + + libcamera::utils::Duration limitExposure = + channelTotalExposures[constraint.channel] * constraint.factor; + LOG(RPiAgc, Debug) << "Limit exposure " << limitExposure; + if ((constraint.bound == AgcChannelConstraint::Bound::UPPER && + filtered_.totalExposure > limitExposure) || + (constraint.bound == AgcChannelConstraint::Bound::LOWER && + filtered_.totalExposure < limitExposure)) { + filtered_.totalExposure = limitExposure; + LOG(RPiAgc, Debug) << "Constraint applies"; + channelBound = true; + } else + LOG(RPiAgc, Debug) << "Constraint does not apply"; + } + + LOG(RPiAgc, Debug) + << "Total exposure after channel constraints " << filtered_.totalExposure; + + return channelBound; +} + +bool AgcChannel::applyDigitalGain(double gain, double targetY, bool channelBound) { double minColourGain = std::min({ awb_.gainR, awb_.gainG, awb_.gainB, 1.0 }); ASSERT(minColourGain != 0.0); @@ -814,8 +858,8 @@ bool AgcChannel::applyDigitalGain(double gain, double targetY) * quickly (and we then approach the correct value more quickly from * below). */ - bool desaturate = targetY > config_.fastReduceThreshold && - gain < sqrt(targetY); + bool desaturate = !channelBound && + targetY > config_.fastReduceThreshold && gain < sqrt(targetY); if (desaturate) dg /= config_.fastReduceThreshold; LOG(RPiAgc, Debug) << "Digital gain " << dg << " desaturate? " << desaturate; diff --git a/src/ipa/rpi/controller/rpi/agc_channel.h b/src/ipa/rpi/controller/rpi/agc_channel.h index ceaab12f..ae826fa8 100644 --- a/src/ipa/rpi/controller/rpi/agc_channel.h +++ b/src/ipa/rpi/controller/rpi/agc_channel.h @@ -21,6 +21,8 @@ namespace RPiController { +using AgcChannelTotalExposures = std::vector; + struct AgcMeteringMode { std::vector weights; int read(const libcamera::YamlObject ¶ms); @@ -95,7 +97,8 @@ public: void disableAuto(); void switchMode(CameraMode const &cameraMode, Metadata *metadata); void prepare(Metadata *imageMetadata); - void process(StatisticsPtr &stats, DeviceStatus const &deviceStatus, Metadata *imageMetadata); + void process(StatisticsPtr &stats, DeviceStatus const &deviceStatus, Metadata *imageMetadata, + const AgcChannelTotalExposures &channelTotalExposures); private: bool updateLockStatus(DeviceStatus const &deviceStatus); @@ -107,7 +110,8 @@ private: double &gain, double &targetY); void computeTargetExposure(double gain); void filterExposure(); - bool applyDigitalGain(double gain, double targetY); + bool applyChannelConstraints(const AgcChannelTotalExposures &channelTotalExposures); + bool applyDigitalGain(double gain, double targetY, bool channelBound); void divideUpExposure(); void writeAndFinish(Metadata *imageMetadata, bool desaturate); libcamera::utils::Duration limitShutter(libcamera::utils::Duration shutter); -- cgit v1.2.1