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libcamera: software_isp: Move exposure+gain to an algorithm module

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This is the last step to fully convert software ISP to Algorithm-based
processing.

The newly introduced frameContext.sensor parameters are set, and the
updated code moved, before calling Algorithm::process() to have the
values up-to-date in stats processing.

Resolves software ISP TODO #10.

Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
This commit is contained in:
Milan Zamazal
2024-09-27 15:46:23 +02:00
committed by Kieran Bingham
parent 54fb3bba81
commit fb8ad13dc3
8 changed files with 228 additions and 137 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/ipa/simple/soft_simple.cpp
+30 -127
View File
@@ -34,23 +34,6 @@ LOG_DEFINE_CATEGORY(IPASoft)
namespace ipa::soft {
/*
* The number of bins to use for the optimal exposure calculations.
*/
static constexpr unsigned int kExposureBinsCount = 5;
/*
* The exposure is optimal when the mean sample value of the histogram is
* in the middle of the range.
*/
static constexpr float kExposureOptimal = kExposureBinsCount / 2.0;
/*
* The below value implements the hysteresis for the exposure adjustment.
* It is small enough to have the exposure close to the optimal, and is big
* enough to prevent the exposure from wobbling around the optimal value.
*/
static constexpr float kExposureSatisfactory = 0.2;
/* Maximum number of frame contexts to be held */
static constexpr uint32_t kMaxFrameContexts = 16;
@@ -58,8 +41,7 @@ class IPASoftSimple : public ipa::soft::IPASoftInterface, public Module
{
public:
IPASoftSimple()
: params_(nullptr), stats_(nullptr),
context_({ {}, {}, { kMaxFrameContexts } })
: context_({ {}, {}, { kMaxFrameContexts } })
{
}
@@ -92,11 +74,6 @@ private:
/* Local parameter storage */
struct IPAContext context_;
int32_t exposureMin_, exposureMax_;
int32_t exposure_;
double againMin_, againMax_, againMinStep_;
double again_;
};
IPASoftSimple::~IPASoftSimple()
@@ -207,20 +184,23 @@ int IPASoftSimple::configure(const IPAConfigInfo &configInfo)
const ControlInfo &exposureInfo = sensorInfoMap_.find(V4L2_CID_EXPOSURE)->second;
const ControlInfo &gainInfo = sensorInfoMap_.find(V4L2_CID_ANALOGUE_GAIN)->second;
exposureMin_ = exposureInfo.min().get<int32_t>();
exposureMax_ = exposureInfo.max().get<int32_t>();
if (!exposureMin_) {
context_.configuration.agc.exposureMin = exposureInfo.min().get<int32_t>();
context_.configuration.agc.exposureMax = exposureInfo.max().get<int32_t>();
if (!context_.configuration.agc.exposureMin) {
LOG(IPASoft, Warning) << "Minimum exposure is zero, that can't be linear";
exposureMin_ = 1;
context_.configuration.agc.exposureMin = 1;
}
int32_t againMin = gainInfo.min().get<int32_t>();
int32_t againMax = gainInfo.max().get<int32_t>();
if (camHelper_) {
againMin_ = camHelper_->gain(againMin);
againMax_ = camHelper_->gain(againMax);
againMinStep_ = (againMax_ - againMin_) / 100.0;
context_.configuration.agc.againMin = camHelper_->gain(againMin);
context_.configuration.agc.againMax = camHelper_->gain(againMax);
context_.configuration.agc.againMinStep =
(context_.configuration.agc.againMax -
context_.configuration.agc.againMin) /
100.0;
} else {
/*
* The camera sensor gain (g) is usually not equal to the value written
@@ -232,13 +212,14 @@ int IPASoftSimple::configure(const IPAConfigInfo &configInfo)
* the AGC algorithm (abrupt near one edge, and very small near the
* other) we limit the range of the gain values used.
*/
againMax_ = againMax;
context_.configuration.agc.againMax = againMax;
if (!againMin) {
LOG(IPASoft, Warning)
<< "Minimum gain is zero, that can't be linear";
againMin_ = std::min(100, againMin / 2 + againMax / 2);
context_.configuration.agc.againMin =
std::min(100, againMin / 2 + againMax / 2);
}
againMinStep_ = 1.0;
context_.configuration.agc.againMinStep = 1.0;
}
for (auto const &algo : algorithms()) {
@@ -247,9 +228,12 @@ int IPASoftSimple::configure(const IPAConfigInfo &configInfo)
return ret;
}
LOG(IPASoft, Info) << "Exposure " << exposureMin_ << "-" << exposureMax_
<< ", gain " << againMin_ << "-" << againMax_
<< " (" << againMinStep_ << ")";
LOG(IPASoft, Info)
<< "Exposure " << context_.configuration.agc.exposureMin << "-"
<< context_.configuration.agc.exposureMax
<< ", gain " << context_.configuration.agc.againMin << "-"
<< context_.configuration.agc.againMax
<< " (" << context_.configuration.agc.againMinStep << ")";
return 0;
}
@@ -284,6 +268,12 @@ void IPASoftSimple::processStats(const uint32_t frame,
const ControlList &sensorControls)
{
IPAFrameContext &frameContext = context_.frameContexts.get(frame);
frameContext.sensor.exposure =
sensorControls.get(V4L2_CID_EXPOSURE).get<int32_t>();
int32_t again = sensorControls.get(V4L2_CID_ANALOGUE_GAIN).get<int32_t>();
frameContext.sensor.gain = camHelper_ ? camHelper_->gain(again) : again;
/*
* Software ISP currently does not produce any metadata. Use an empty
* ControlList for now.
@@ -294,37 +284,6 @@ void IPASoftSimple::processStats(const uint32_t frame,
for (auto const &algo : algorithms())
algo->process(context_, frame, frameContext, stats_, metadata);
/* \todo Switch to the libipa/algorithm.h API someday. */
/*
* Calculate Mean Sample Value (MSV) according to formula from:
* https://www.araa.asn.au/acra/acra2007/papers/paper84final.pdf
*/
const uint8_t blackLevel = context_.activeState.blc.level;
const unsigned int blackLevelHistIdx =
blackLevel / (256 / SwIspStats::kYHistogramSize);
const unsigned int histogramSize =
SwIspStats::kYHistogramSize - blackLevelHistIdx;
const unsigned int yHistValsPerBin = histogramSize / kExposureBinsCount;
const unsigned int yHistValsPerBinMod =
histogramSize / (histogramSize % kExposureBinsCount + 1);
int exposureBins[kExposureBinsCount] = {};
unsigned int denom = 0;
unsigned int num = 0;
for (unsigned int i = 0; i < histogramSize; i++) {
unsigned int idx = (i - (i / yHistValsPerBinMod)) / yHistValsPerBin;
exposureBins[idx] += stats_->yHistogram[blackLevelHistIdx + i];
}
for (unsigned int i = 0; i < kExposureBinsCount; i++) {
LOG(IPASoft, Debug) << i << ": " << exposureBins[i];
denom += exposureBins[i];
num += exposureBins[i] * (i + 1);
}
float exposureMSV = static_cast<float>(num) / denom;
/* Sanity check */
if (!sensorControls.contains(V4L2_CID_EXPOSURE) ||
!sensorControls.contains(V4L2_CID_ANALOGUE_GAIN)) {
@@ -332,70 +291,14 @@ void IPASoftSimple::processStats(const uint32_t frame,
return;
}
exposure_ = sensorControls.get(V4L2_CID_EXPOSURE).get<int32_t>();
int32_t again = sensorControls.get(V4L2_CID_ANALOGUE_GAIN).get<int32_t>();
again_ = camHelper_ ? camHelper_->gain(again) : again;
updateExposure(exposureMSV);
ControlList ctrls(sensorInfoMap_);
ctrls.set(V4L2_CID_EXPOSURE, exposure_);
auto &againNew = context_.activeState.agc.again;
ctrls.set(V4L2_CID_EXPOSURE, context_.activeState.agc.exposure);
ctrls.set(V4L2_CID_ANALOGUE_GAIN,
static_cast<int32_t>(camHelper_ ? camHelper_->gainCode(again_) : again_));
static_cast<int32_t>(camHelper_ ? camHelper_->gainCode(againNew) : againNew));
setSensorControls.emit(ctrls);
LOG(IPASoft, Debug) << "exposureMSV " << exposureMSV
<< " exp " << exposure_ << " again " << again_
<< " black level " << static_cast<unsigned int>(blackLevel);
}
void IPASoftSimple::updateExposure(double exposureMSV)
{
/*
* kExpDenominator of 10 gives ~10% increment/decrement;
* kExpDenominator of 5 - about ~20%
*/
static constexpr uint8_t kExpDenominator = 10;
static constexpr uint8_t kExpNumeratorUp = kExpDenominator + 1;
static constexpr uint8_t kExpNumeratorDown = kExpDenominator - 1;
double next;
if (exposureMSV < kExposureOptimal - kExposureSatisfactory) {
next = exposure_ * kExpNumeratorUp / kExpDenominator;
if (next - exposure_ < 1)
exposure_ += 1;
else
exposure_ = next;
if (exposure_ >= exposureMax_) {
next = again_ * kExpNumeratorUp / kExpDenominator;
if (next - again_ < againMinStep_)
again_ += againMinStep_;
else
again_ = next;
}
}
if (exposureMSV > kExposureOptimal + kExposureSatisfactory) {
if (exposure_ == exposureMax_ && again_ > againMin_) {
next = again_ * kExpNumeratorDown / kExpDenominator;
if (again_ - next < againMinStep_)
again_ -= againMinStep_;
else
again_ = next;
} else {
next = exposure_ * kExpNumeratorDown / kExpDenominator;
if (exposure_ - next < 1)
exposure_ -= 1;
else
exposure_ = next;
}
}
exposure_ = std::clamp(exposure_, exposureMin_, exposureMax_);
again_ = std::clamp(again_, againMin_, againMax_);
}
std::string IPASoftSimple::logPrefix() const