diff options
Diffstat (limited to 'src/ipa/rkisp1/algorithms/agc.cpp')
| -rw-r--r-- | src/ipa/rkisp1/algorithms/agc.cpp | 278 |
1 files changed, 74 insertions, 204 deletions
diff --git a/src/ipa/rkisp1/algorithms/agc.cpp b/src/ipa/rkisp1/algorithms/agc.cpp index 47a6f7b2..50e0690f 100644 --- a/src/ipa/rkisp1/algorithms/agc.cpp +++ b/src/ipa/rkisp1/algorithms/agc.cpp @@ -2,7 +2,7 @@ /* * Copyright (C) 2021-2022, Ideas On Board * - * agc.cpp - AGC/AEC mean-based control algorithm + * AGC/AEC mean-based control algorithm */ #include "agc.h" @@ -36,32 +36,32 @@ namespace ipa::rkisp1::algorithms { LOG_DEFINE_CATEGORY(RkISP1Agc) -/* Minimum limit for analogue gain value */ -static constexpr double kMinAnalogueGain = 1.0; - -/* \todo Honour the FrameDurationLimits control instead of hardcoding a limit */ -static constexpr utils::Duration kMaxShutterSpeed = 60ms; - -/* Number of frames to wait before calculating stats on minimum exposure */ -static constexpr uint32_t kNumStartupFrames = 10; - -/* Target value to reach for the top 2% of the histogram */ -static constexpr double kEvGainTarget = 0.5; +Agc::Agc() +{ + supportsRaw_ = true; +} -/* - * Relative luminance target. +/** + * \brief Initialise the AGC algorithm from tuning files + * \param[in] context The shared IPA context + * \param[in] tuningData The YamlObject containing Agc tuning data * - * It's a number that's chosen so that, when the camera points at a grey - * target, the resulting image brightness is considered right. + * This function calls the base class' tuningData parsers to discover which + * control values are supported. * - * \todo Why is the value different between IPU3 and RkISP1 ? + * \return 0 on success or errors from the base class */ -static constexpr double kRelativeLuminanceTarget = 0.4; - -Agc::Agc() - : frameCount_(0), filteredExposure_(0s) +int Agc::init(IPAContext &context, const YamlObject &tuningData) { - supportsRaw_ = true; + int ret; + + ret = parseTuningData(tuningData); + if (ret) + return ret; + + context.ctrlMap.merge(controls()); + + return 0; } /** @@ -81,6 +81,9 @@ int Agc::configure(IPAContext &context, const IPACameraSensorInfo &configInfo) context.activeState.agc.manual.exposure = context.activeState.agc.automatic.exposure; context.activeState.agc.autoEnabled = !context.configuration.raw; + context.activeState.agc.constraintMode = constraintModes().begin()->first; + context.activeState.agc.exposureMode = exposureModeHelpers().begin()->first; + /* * Define the measurement window for AGC as a centered rectangle * covering 3/4 of the image width and height. @@ -90,11 +93,14 @@ int Agc::configure(IPAContext &context, const IPACameraSensorInfo &configInfo) context.configuration.agc.measureWindow.h_size = 3 * configInfo.outputSize.width / 4; context.configuration.agc.measureWindow.v_size = 3 * configInfo.outputSize.height / 4; - /* - * \todo Use the upcoming per-frame context API that will provide a - * frame index - */ - frameCount_ = 0; + /* \todo Run this again when FrameDurationLimits is passed in */ + setLimits(context.configuration.sensor.minShutterSpeed, + context.configuration.sensor.maxShutterSpeed, + context.configuration.sensor.minAnalogueGain, + context.configuration.sensor.maxAnalogueGain); + + resetFrameCount(); + return 0; } @@ -188,127 +194,24 @@ void Agc::prepare(IPAContext &context, const uint32_t frame, params->module_en_update |= RKISP1_CIF_ISP_MODULE_HST; } -/** - * \brief Apply a filter on the exposure value to limit the speed of changes - * \param[in] exposureValue The target exposure from the AGC algorithm - * - * The speed of the filter is adaptive, and will produce the target quicker - * during startup, or when the target exposure is within 20% of the most recent - * filter output. - * - * \return The filtered exposure - */ -utils::Duration Agc::filterExposure(utils::Duration exposureValue) -{ - double speed = 0.2; - - /* Adapt instantly if we are in startup phase. */ - if (frameCount_ < kNumStartupFrames) - speed = 1.0; - - /* - * If we are close to the desired result, go faster to avoid making - * multiple micro-adjustments. - * \todo Make this customisable? - */ - if (filteredExposure_ < 1.2 * exposureValue && - filteredExposure_ > 0.8 * exposureValue) - speed = sqrt(speed); - - filteredExposure_ = speed * exposureValue + - filteredExposure_ * (1.0 - speed); - - LOG(RkISP1Agc, Debug) << "After filtering, exposure " << filteredExposure_; - - return filteredExposure_; -} - -/** - * \brief Estimate the new exposure and gain values - * \param[inout] context The shared IPA Context - * \param[in] frameContext The FrameContext for this frame - * \param[in] yGain The gain calculated on the current brightness level - * \param[in] iqMeanGain The gain calculated based on the relative luminance target - */ -void Agc::computeExposure(IPAContext &context, IPAFrameContext &frameContext, - double yGain, double iqMeanGain) +void Agc::fillMetadata(IPAContext &context, IPAFrameContext &frameContext, + ControlList &metadata) { - IPASessionConfiguration &configuration = context.configuration; - IPAActiveState &activeState = context.activeState; - - /* Get the effective exposure and gain applied on the sensor. */ - uint32_t exposure = frameContext.sensor.exposure; - double analogueGain = frameContext.sensor.gain; - - /* Use the highest of the two gain estimates. */ - double evGain = std::max(yGain, iqMeanGain); - - utils::Duration minShutterSpeed = configuration.sensor.minShutterSpeed; - utils::Duration maxShutterSpeed = std::min(configuration.sensor.maxShutterSpeed, - kMaxShutterSpeed); - - double minAnalogueGain = std::max(configuration.sensor.minAnalogueGain, - kMinAnalogueGain); - double maxAnalogueGain = configuration.sensor.maxAnalogueGain; - - /* Consider within 1% of the target as correctly exposed. */ - if (utils::abs_diff(evGain, 1.0) < 0.01) - return; - - /* extracted from Rpi::Agc::computeTargetExposure. */ - - /* Calculate the shutter time in seconds. */ - utils::Duration currentShutter = exposure * configuration.sensor.lineDuration; - - /* - * Update the exposure value for the next computation using the values - * of exposure and gain really used by the sensor. - */ - utils::Duration effectiveExposureValue = currentShutter * analogueGain; - - LOG(RkISP1Agc, Debug) << "Actual total exposure " << currentShutter * analogueGain - << " Shutter speed " << currentShutter - << " Gain " << analogueGain - << " Needed ev gain " << evGain; - - /* - * Calculate the current exposure value for the scene as the latest - * exposure value applied multiplied by the new estimated gain. - */ - utils::Duration exposureValue = effectiveExposureValue * evGain; - - /* Clamp the exposure value to the min and max authorized. */ - utils::Duration maxTotalExposure = maxShutterSpeed * maxAnalogueGain; - exposureValue = std::min(exposureValue, maxTotalExposure); - LOG(RkISP1Agc, Debug) << "Target total exposure " << exposureValue - << ", maximum is " << maxTotalExposure; - - /* - * Divide the exposure value as new exposure and gain values. - * \todo estimate if we need to desaturate - */ - exposureValue = filterExposure(exposureValue); - - /* - * Push the shutter time up to the maximum first, and only then - * increase the gain. - */ - utils::Duration shutterTime = std::clamp<utils::Duration>(exposureValue / minAnalogueGain, - minShutterSpeed, maxShutterSpeed); - double stepGain = std::clamp(exposureValue / shutterTime, - minAnalogueGain, maxAnalogueGain); - LOG(RkISP1Agc, Debug) << "Divided up shutter and gain are " - << shutterTime << " and " - << stepGain; + utils::Duration exposureTime = context.configuration.sensor.lineDuration + * frameContext.sensor.exposure; + metadata.set(controls::AnalogueGain, frameContext.sensor.gain); + metadata.set(controls::ExposureTime, exposureTime.get<std::micro>()); - /* Update the estimated exposure and gain. */ - activeState.agc.automatic.exposure = shutterTime / configuration.sensor.lineDuration; - activeState.agc.automatic.gain = stepGain; + /* \todo Use VBlank value calculated from each frame exposure. */ + uint32_t vTotal = context.configuration.sensor.size.height + + context.configuration.sensor.defVBlank; + utils::Duration frameDuration = context.configuration.sensor.lineDuration + * vTotal; + metadata.set(controls::FrameDuration, frameDuration.get<std::micro>()); } /** * \brief Estimate the relative luminance of the frame with a given gain - * \param[in] expMeans The mean luminance values, from the RkISP1 statistics * \param[in] gain The gain to apply to the frame * * This function estimates the average relative luminance of the frame that @@ -322,8 +225,6 @@ void Agc::computeExposure(IPAContext &context, IPAFrameContext &frameContext, * YUV doesn't take into account the fact that the R, G and B components * contribute differently to the relative luminance. * - * \todo Have a dedicated YUV algorithm ? - * * The values are normalized to the [0.0, 1.0] range, where 1.0 corresponds to a * theoretical perfect reflector of 100% reference white. * @@ -332,45 +233,17 @@ void Agc::computeExposure(IPAContext &context, IPAFrameContext &frameContext, * * \return The relative luminance */ -double Agc::estimateLuminance(Span<const uint8_t> expMeans, double gain) +double Agc::estimateLuminance(double gain) const { double ySum = 0.0; /* Sum the averages, saturated to 255. */ - for (uint8_t expMean : expMeans) + for (uint8_t expMean : expMeans_) ySum += std::min(expMean * gain, 255.0); /* \todo Weight with the AWB gains */ - return ySum / expMeans.size() / 255; -} - -/** - * \brief Estimate the mean value of the top 2% of the histogram - * \param[in] hist The histogram statistics computed by the RkISP1 - * \return The mean value of the top 2% of the histogram - */ -double Agc::measureBrightness(Span<const uint32_t> hist) const -{ - Histogram histogram{ hist }; - /* Estimate the quantile mean of the top 2% of the histogram. */ - return histogram.interQuantileMean(0.98, 1.0); -} - -void Agc::fillMetadata(IPAContext &context, IPAFrameContext &frameContext, - ControlList &metadata) -{ - utils::Duration exposureTime = context.configuration.sensor.lineDuration - * frameContext.sensor.exposure; - metadata.set(controls::AnalogueGain, frameContext.sensor.gain); - metadata.set(controls::ExposureTime, exposureTime.get<std::micro>()); - - /* \todo Use VBlank value calculated from each frame exposure. */ - uint32_t vTotal = context.configuration.sensor.size.height - + context.configuration.sensor.defVBlank; - utils::Duration frameDuration = context.configuration.sensor.lineDuration - * vTotal; - metadata.set(controls::FrameDuration, frameDuration.get<std::micro>()); + return ySum / expMeans_.size() / 255; } /** @@ -404,41 +277,38 @@ void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame, const rkisp1_cif_isp_stat *params = &stats->params; ASSERT(stats->meas_type & RKISP1_CIF_ISP_STAT_AUTOEXP); - Span<const uint8_t> ae{ params->ae.exp_mean, context.hw->numAeCells }; - Span<const uint32_t> hist{ - params->hist.hist_bins, - context.hw->numHistogramBins - }; - - double iqMean = measureBrightness(hist); - double iqMeanGain = kEvGainTarget * hist.size() / iqMean; + /* The lower 4 bits are fractional and meant to be discarded. */ + Histogram hist({ params->hist.hist_bins, context.hw->numHistogramBins }, + [](uint32_t x) { return x >> 4; }); + expMeans_ = { params->ae.exp_mean, context.hw->numAeCells }; /* - * Estimate the gain needed to achieve a relative luminance target. To - * account for non-linearity caused by saturation, the value needs to be - * estimated in an iterative process, as multiplying by a gain will not - * increase the relative luminance by the same factor if some image - * regions are saturated. + * The Agc algorithm needs to know the effective exposure value that was + * applied to the sensor when the statistics were collected. */ - double yGain = 1.0; - double yTarget = kRelativeLuminanceTarget; - - for (unsigned int i = 0; i < 8; i++) { - double yValue = estimateLuminance(ae, yGain); - double extra_gain = std::min(10.0, yTarget / (yValue + .001)); - - yGain *= extra_gain; - LOG(RkISP1Agc, Debug) << "Y value: " << yValue - << ", Y target: " << yTarget - << ", gives gain " << yGain; - if (extra_gain < 1.01) - break; - } + utils::Duration exposureTime = context.configuration.sensor.lineDuration + * frameContext.sensor.exposure; + double analogueGain = frameContext.sensor.gain; + utils::Duration effectiveExposureValue = exposureTime * analogueGain; + + utils::Duration shutterTime; + double aGain, dGain; + std::tie(shutterTime, aGain, dGain) = + calculateNewEv(context.activeState.agc.constraintMode, + context.activeState.agc.exposureMode, + hist, effectiveExposureValue); - computeExposure(context, frameContext, yGain, iqMeanGain); - frameCount_++; + LOG(RkISP1Agc, Debug) + << "Divided up shutter, analogue gain and digital gain are " + << shutterTime << ", " << aGain << " and " << dGain; + + IPAActiveState &activeState = context.activeState; + /* Update the estimated exposure and gain. */ + activeState.agc.automatic.exposure = shutterTime / context.configuration.sensor.lineDuration; + activeState.agc.automatic.gain = aGain; fillMetadata(context, frameContext, metadata); + expMeans_ = {}; } REGISTER_IPA_ALGORITHM(Agc, "Agc") |