ipa: ipu3: Move IPU3 agc into algorithms

Now that the interface is properly used by the AGC class, move it into
ipa::ipu3::algorithms and let the loops do the calls.
As we need to exchange the exposure_ and gain_ by passing them through the
FrameContext, use the calculated values in setControls() function to
ease the reading.

Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 0 insertions, 200 deletions

diff --git a/src/ipa/ipu3/ipu3_agc.cpp b/src/ipa/ipu3/ipu3_agc.cpp
deleted file mode 100644
index 1c156b89..00000000
--- a/src/ipa/ipu3/ipu3_agc.cpp
+++ /dev/null
@@ -1,200 +0,0 @@
-/* SPDX-License-Identifier: LGPL-2.1-or-later */
-/*
- * Copyright (C) 2021, Ideas On Board
- *
- * ipu3_agc.cpp - AGC/AEC control algorithm
- */
-
-#include "ipu3_agc.h"
-
-#include <algorithm>
-#include <chrono>
-#include <cmath>
-
-#include <libcamera/base/log.h>
-
-#include <libcamera/ipa/core_ipa_interface.h>
-
-#include "libipa/histogram.h"
-
-namespace libcamera {
-
-using namespace std::literals::chrono_literals;
-
-namespace ipa::ipu3 {
-
-LOG_DEFINE_CATEGORY(IPU3Agc)
-
-/* Number of frames to wait before calculating stats on minimum exposure */
-static constexpr uint32_t kInitialFrameMinAECount = 4;
-/* Number of frames to wait between new gain/exposure estimations */
-static constexpr uint32_t kFrameSkipCount = 6;
-
-/* Maximum ISO value for analogue gain */
-static constexpr uint32_t kMinISO = 100;
-static constexpr uint32_t kMaxISO = 1500;
-
-/* Maximum analogue gain value
- * \todo grab it from a camera helper */
-static constexpr uint32_t kMinGain = kMinISO / 100;
-static constexpr uint32_t kMaxGain = kMaxISO / 100;
-
-/* \todo use calculated value based on sensor */
-static constexpr uint32_t kMinExposure = 1;
-static constexpr uint32_t kMaxExposure = 1976;
-
-/* Histogram constants */
-static constexpr uint32_t knumHistogramBins = 256;
-static constexpr double kEvGainTarget = 0.5;
-
-/* A cell is 8 bytes and contains averages for RGB values and saturation ratio */
-static constexpr uint8_t kCellSize = 8;
-
-IPU3Agc::IPU3Agc()
-	: frameCount_(0), lastFrame_(0), iqMean_(0.0), lineDuration_(0s),
-	  maxExposureTime_(0s), prevExposure_(0s), prevExposureNoDg_(0s),
-	  currentExposure_(0s), currentExposureNoDg_(0s)
-{
-}
-
-int IPU3Agc::configure(IPAContext &context, const IPAConfigInfo &configInfo)
-{
-	aeGrid_ = context.configuration.grid.bdsGrid;
-
-	lineDuration_ = configInfo.sensorInfo.lineLength * 1.0s
-		      / configInfo.sensorInfo.pixelRate;
-	maxExposureTime_ = kMaxExposure * lineDuration_;
-
-	return 0;
-}
-
-void IPU3Agc::processBrightness(const ipu3_uapi_stats_3a *stats)
-{
-	const struct ipu3_uapi_grid_config statsAeGrid = stats->stats_4a_config.awb_config.grid;
-	Rectangle aeRegion = { statsAeGrid.x_start,
-			       statsAeGrid.y_start,
-			       static_cast<unsigned int>(statsAeGrid.x_end - statsAeGrid.x_start) + 1,
-			       static_cast<unsigned int>(statsAeGrid.y_end - statsAeGrid.y_start) + 1 };
-	Point topleft = aeRegion.topLeft();
-	int topleftX = topleft.x >> aeGrid_.block_width_log2;
-	int topleftY = topleft.y >> aeGrid_.block_height_log2;
-
-	/* Align to the grid cell width and height */
-	uint32_t startX = topleftX << aeGrid_.block_width_log2;
-	uint32_t startY = topleftY * aeGrid_.width << aeGrid_.block_width_log2;
-	uint32_t endX = (startX + (aeRegion.size().width >> aeGrid_.block_width_log2)) << aeGrid_.block_width_log2;
-	uint32_t i, j;
-	uint32_t count = 0;
-
-	uint32_t hist[knumHistogramBins] = { 0 };
-	for (j = topleftY;
-	     j < topleftY + (aeRegion.size().height >> aeGrid_.block_height_log2);
-	     j++) {
-		for (i = startX + startY; i < endX + startY; i += kCellSize) {
-			/*
-			 * The grid width (and maybe height) is not reliable.
-			 * We observed a bit shift which makes the value 160 to be 32 in the stats grid.
-			 * Use the one passed at init time.
-			 */
-			if (stats->awb_raw_buffer.meta_data[i + 4 + j * aeGrid_.width] == 0) {
-				uint8_t Gr = stats->awb_raw_buffer.meta_data[i + 0 + j * aeGrid_.width];
-				uint8_t Gb = stats->awb_raw_buffer.meta_data[i + 3 + j * aeGrid_.width];
-				hist[(Gr + Gb) / 2]++;
-				count++;
-			}
-		}
-	}
-
-	/* Estimate the quantile mean of the top 2% of the histogram */
-	iqMean_ = Histogram(Span<uint32_t>(hist)).interQuantileMean(0.98, 1.0);
-}
-
-void IPU3Agc::filterExposure()
-{
-	double speed = 0.2;
-	if (prevExposure_ == 0s) {
-		/* DG stands for digital gain.*/
-		prevExposure_ = currentExposure_;
-		prevExposureNoDg_ = currentExposureNoDg_;
-	} else {
-		/*
-		 * If we are close to the desired result, go faster to avoid making
-		 * multiple micro-adjustments.
-		 * \ todo: Make this customisable?
-		 */
-		if (prevExposure_ < 1.2 * currentExposure_ &&
-		    prevExposure_ > 0.8 * currentExposure_)
-			speed = sqrt(speed);
-
-		prevExposure_ = speed * currentExposure_ +
-				prevExposure_ * (1.0 - speed);
-		prevExposureNoDg_ = speed * currentExposureNoDg_ +
-				prevExposureNoDg_ * (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).
-	 */
-	double fastReduceThreshold = 0.4;
-	if (prevExposureNoDg_ <
-	    prevExposure_ * fastReduceThreshold)
-		prevExposureNoDg_ = prevExposure_ * fastReduceThreshold;
-	LOG(IPU3Agc, Debug) << "After filtering, total_exposure " << prevExposure_;
-}
-
-void IPU3Agc::lockExposureGain(uint32_t &exposure, double &gain)
-{
-	/* Algorithm initialization should wait for first valid frames */
-	/* \todo - have a number of frames given by DelayedControls ?
-	 * - implement a function for IIR */
-	if ((frameCount_ < kInitialFrameMinAECount) || (frameCount_ - lastFrame_ < kFrameSkipCount))
-		return;
-
-	/* Are we correctly exposed ? */
-	if (std::abs(iqMean_ - kEvGainTarget * knumHistogramBins) <= 1) {
-		LOG(IPU3Agc, Debug) << "!!! Good exposure with iqMean = " << iqMean_;
-	} else {
-		double newGain = kEvGainTarget * knumHistogramBins / iqMean_;
-
-		/* extracted from Rpi::Agc::computeTargetExposure */
-		libcamera::utils::Duration currentShutter = exposure * lineDuration_;
-		currentExposureNoDg_ = currentShutter * gain;
-		LOG(IPU3Agc, Debug) << "Actual total exposure " << currentExposureNoDg_
-				    << " Shutter speed " << currentShutter
-				    << " Gain " << gain;
-		currentExposure_ = currentExposureNoDg_ * newGain;
-		libcamera::utils::Duration maxTotalExposure = maxExposureTime_ * kMaxGain;
-		currentExposure_ = std::min(currentExposure_, maxTotalExposure);
-		LOG(IPU3Agc, Debug) << "Target total exposure " << currentExposure_;
-
-		/* \todo: estimate if we need to desaturate */
-		filterExposure();
-
-		libcamera::utils::Duration newExposure = 0.0s;
-		if (currentShutter < maxExposureTime_) {
-			exposure = std::clamp(static_cast<uint32_t>(exposure * currentExposure_ / currentExposureNoDg_), kMinExposure, kMaxExposure);
-			newExposure = currentExposure_ / exposure;
-			gain = std::clamp(static_cast<uint32_t>(gain * currentExposure_ / newExposure), kMinGain, kMaxGain);
-		} else if (currentShutter >= maxExposureTime_) {
-			gain = std::clamp(static_cast<uint32_t>(gain * currentExposure_ / currentExposureNoDg_), kMinGain, kMaxGain);
-			newExposure = currentExposure_ / gain;
-			exposure = std::clamp(static_cast<uint32_t>(exposure * currentExposure_ / newExposure), kMinExposure, kMaxExposure);
-		}
-		LOG(IPU3Agc, Debug) << "Adjust exposure " << exposure * lineDuration_ << " and gain " << gain;
-	}
-	lastFrame_ = frameCount_;
-}
-
-void IPU3Agc::process(IPAContext &context, const ipu3_uapi_stats_3a *stats)
-{
-	uint32_t &exposure = context.frameContext.agc.exposure;
-	double &gain = context.frameContext.agc.gain;
-	processBrightness(stats);
-	lockExposureGain(exposure, gain);
-	frameCount_++;
-}
-
-} /* namespace ipa::ipu3 */
-
-} /* namespace libcamera */