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>
This commit is contained in:
Jean-Michel Hautbois
parent
b145ae4242
commit
93802f600c
5 changed files with 28 additions and 32 deletions
200
src/ipa/ipu3/algorithms/agc.cpp
Normal file
200
src/ipa/ipu3/algorithms/agc.cpp
Normal file
|
|
@ -0,0 +1,200 @@
|
|||
/* SPDX-License-Identifier: LGPL-2.1-or-later */
|
||||
/*
|
||||
* Copyright (C) 2021, Ideas On Board
|
||||
*
|
||||
* ipu3_agc.cpp - AGC/AEC control algorithm
|
||||
*/
|
||||
|
||||
#include "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::algorithms {
|
||||
|
||||
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;
|
||||
|
||||
Agc::Agc()
|
||||
: frameCount_(0), lastFrame_(0), iqMean_(0.0), lineDuration_(0s),
|
||||
maxExposureTime_(0s), prevExposure_(0s), prevExposureNoDg_(0s),
|
||||
currentExposure_(0s), currentExposureNoDg_(0s)
|
||||
{
|
||||
}
|
||||
|
||||
int Agc::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 Agc::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 Agc::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 Agc::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 Agc::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::algorithms */
|
||||
|
||||
} /* namespace libcamera */
|
||||
Loading…
Add table
Add a link
Reference in a new issue