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ipa: ipu3: agc: Change exposure limits

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We are using arbitrary constants for the exposure limit in a number of
lines.

Instead of using static constants for those, use the limits of the
sensor passed in IPASessionConfiguration and cache those.

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 2021-10-12 16:41:20 +02:00
parent 02686a052a
commit 355503233b
2 changed files with 22 additions and 16 deletions
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35
src/ipa/ipu3/algorithms/agc.cpp
View file

@ -39,18 +39,14 @@ static constexpr uint32_t kMaxISO = 1500;
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;
Agc::Agc()
: frameCount_(0), lastFrame_(0), iqMean_(0.0), lineDuration_(0s),
maxExposureTime_(0s), filteredExposure_(0s), filteredExposureNoDg_(0s),
currentExposure_(0s), currentExposureNoDg_(0s)
minExposureLines_(0), maxExposureLines_(0), filteredExposure_(0s),
filteredExposureNoDg_(0s), currentExposure_(0s), currentExposureNoDg_(0s)
{
}
@ -60,13 +56,15 @@ int Agc::configure(IPAContext &context, const IPAConfigInfo &configInfo)
lineDuration_ = configInfo.sensorInfo.lineLength * 1.0s
/ configInfo.sensorInfo.pixelRate;
maxExposureTime_ = context.configuration.agc.maxShutterSpeed;
/* \todo replace the exposure in lines storage with time based ones. */
minExposureLines_ = context.configuration.agc.minShutterSpeed / lineDuration_;
maxExposureLines_ = context.configuration.agc.maxShutterSpeed / lineDuration_;
/* Configure the default exposure and gain. */
context.frameContext.agc.gain =
context.configuration.agc.minAnalogueGain;
context.frameContext.agc.exposure =
context.configuration.agc.minShutterSpeed / lineDuration_;
context.frameContext.agc.exposure = minExposureLines_;
return 0;
}
@ -151,23 +149,30 @@ void Agc::lockExposureGain(uint32_t &exposure, double &gain)
LOG(IPU3Agc, Debug) << "Actual total exposure " << currentExposureNoDg_
<< " Shutter speed " << currentShutter
<< " Gain " << gain;
currentExposure_ = currentExposureNoDg_ * newGain;
utils::Duration maxTotalExposure = maxExposureTime_ * kMaxGain;
utils::Duration maxShutterSpeed = maxExposureLines_ * lineDuration_;
utils::Duration maxTotalExposure = maxShutterSpeed * kMaxGain;
currentExposure_ = std::min(currentExposure_, maxTotalExposure);
LOG(IPU3Agc, Debug) << "Target total exposure " << currentExposure_;
LOG(IPU3Agc, Debug) << "Target total exposure " << currentExposure_
<< ", maximum is " << maxTotalExposure;
/* \todo: estimate if we need to desaturate */
filterExposure();
utils::Duration newExposure = 0.0s;
if (currentShutter < maxExposureTime_) {
exposure = std::clamp(static_cast<uint32_t>(exposure * currentExposure_ / currentExposureNoDg_), kMinExposure, kMaxExposure);
if (currentShutter < maxShutterSpeed) {
exposure = std::clamp<uint32_t>(exposure * currentExposure_ / currentExposureNoDg_,
minExposureLines_,
maxExposureLines_);
newExposure = currentExposure_ / exposure;
gain = std::clamp(static_cast<uint32_t>(gain * currentExposure_ / newExposure), kMinGain, kMaxGain);
} else if (currentShutter >= maxExposureTime_) {
} else {
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);
exposure = std::clamp<uint32_t>(exposure * currentExposure_ / newExposure,
minExposureLines_,
maxExposureLines_);
}
LOG(IPU3Agc, Debug) << "Adjust exposure " << exposure * lineDuration_ << " and gain " << gain;
}

3
src/ipa/ipu3/algorithms/agc.h
View file

@ -42,7 +42,8 @@ private:
double iqMean_;
utils::Duration lineDuration_;
utils::Duration maxExposureTime_;
uint32_t minExposureLines_;
uint32_t maxExposureLines_;
utils::Duration filteredExposure_;
utils::Duration filteredExposureNoDg_;