[v4,18/18] libcamera: Soft IPA: use CameraSensorHelper for analogue gain
diff mbox series

Message ID 20240229183654.7206-19-hdegoede@redhat.com
State Superseded
Headers show
Series
  • libcamera: introduce Software ISP and Software IPA
Related show

Commit Message

Hans de Goede Feb. 29, 2024, 6:36 p.m. UTC
From: Andrei Konovalov <andrey.konovalov.ynk@gmail.com>

Use CameraSensorHelper to convert the analogue gain code read from the
camera sensor into real analogue gain value. In the future this makes
it possible to use faster AE/AGC algorithm. For now the same AE/AGC
algorithm is used, but even then the CameraSensorHelper lets us use the
full range of analogue gain values.

If there is no CameraSensorHelper for the camera sensor in use, a
warning log message is printed, and the AE/AGC works exactly as before
this change.

Signed-off-by: Andrei Konovalov <andrey.konovalov.ynk@gmail.com>
---
 .../internal/software_isp/software_isp.h      |  3 +-
 src/ipa/simple/soft_simple.cpp                | 77 ++++++++++++-------
 src/libcamera/pipeline/simple/simple.cpp      |  2 +-
 src/libcamera/software_isp/software_isp.cpp   |  8 +-
 4 files changed, 57 insertions(+), 33 deletions(-)

Patch
diff mbox series

diff --git a/include/libcamera/internal/software_isp/software_isp.h b/include/libcamera/internal/software_isp/software_isp.h
index 8d25e979..2a6db7ba 100644
--- a/include/libcamera/internal/software_isp/software_isp.h
+++ b/include/libcamera/internal/software_isp/software_isp.h
@@ -26,6 +26,7 @@ 
 #include <libcamera/ipa/soft_ipa_interface.h>
 #include <libcamera/ipa/soft_ipa_proxy.h>
 
+#include "libcamera/internal/camera_sensor.h"
 #include "libcamera/internal/dma_heaps.h"
 #include "libcamera/internal/pipeline_handler.h"
 #include "libcamera/internal/shared_mem_object.h"
@@ -43,7 +44,7 @@  LOG_DECLARE_CATEGORY(SoftwareIsp)
 class SoftwareIsp
 {
 public:
-	SoftwareIsp(PipelineHandler *pipe, const ControlInfoMap &sensorControls);
+	SoftwareIsp(PipelineHandler *pipe, const CameraSensor *sensor);
 	~SoftwareIsp();
 
 	int loadConfiguration([[maybe_unused]] const std::string &filename) { return 0; }
diff --git a/src/ipa/simple/soft_simple.cpp b/src/ipa/simple/soft_simple.cpp
index ac027568..e4d64762 100644
--- a/src/ipa/simple/soft_simple.cpp
+++ b/src/ipa/simple/soft_simple.cpp
@@ -22,6 +22,8 @@ 
 #include "libcamera/internal/software_isp/debayer_params.h"
 #include "libcamera/internal/software_isp/swisp_stats.h"
 
+#include "libipa/camera_sensor_helper.h"
+
 #include "black_level.h"
 
 namespace libcamera {
@@ -67,18 +69,27 @@  private:
 	DebayerParams *params_;
 	SwIspStats *stats_;
 	BlackLevel blackLevel_;
+	std::unique_ptr<CameraSensorHelper> camHelper_;
 
 	int32_t exposure_min_, exposure_max_;
-	int32_t again_min_, again_max_;
-	int32_t again_, exposure_;
+	int32_t exposure_;
+	double again_min_, again_max_, againMinStep_;
+	double again_;
 	unsigned int ignore_updates_;
 };
 
-int IPASoftSimple::init([[maybe_unused]] const IPASettings &settings,
+int IPASoftSimple::init(const IPASettings &settings,
 			const SharedFD &fdStats,
 			const SharedFD &fdParams,
 			const ControlInfoMap &sensorInfoMap)
 {
+	camHelper_ = CameraSensorHelperFactoryBase::create(settings.sensorModel);
+	if (camHelper_ == nullptr) {
+		LOG(IPASoft, Warning)
+			<< "Failed to create camera sensor helper for "
+			<< settings.sensorModel;
+	}
+
 	fdStats_ = fdStats;
 	if (!fdStats_.isValid()) {
 		LOG(IPASoft, Error) << "Invalid Statistics handle";
@@ -132,25 +143,35 @@  int IPASoftSimple::configure(const ControlInfoMap &sensorInfoMap)
 		exposure_min_ = 1;
 	}
 
-	again_min_ = gain_info.min().get<int32_t>();
-	again_max_ = gain_info.max().get<int32_t>();
-	/*
-	 * The camera sensor gain (g) is usually not equal to the value written
-	 * into the gain register (x). But the way how the AGC algorithm changes
-	 * the gain value to make the total exposure closer to the optimum assumes
-	 * that g(x) is not too far from linear function. If the minimal gain is 0,
-	 * the g(x) is likely to be far from the linear, like g(x) = a / (b * x + c).
-	 * To avoid unexpected changes to the gain by the AGC algorithm (abrupt near
-	 * one edge, and very small near the other) we limit the range of the gain
-	 * values used.
-	 */
-	if (!again_min_) {
-		LOG(IPASoft, Warning) << "Minimum gain is zero, that can't be linear";
-		again_min_ = std::min(100, again_min_ / 2 + again_max_ / 2);
+	int32_t again_min = gain_info.min().get<int32_t>();
+	int32_t again_max = gain_info.max().get<int32_t>();
+
+	if (camHelper_) {
+		again_min_ = camHelper_->gain(again_min);
+		again_max_ = camHelper_->gain(again_max);
+		againMinStep_ = (again_max_ - again_min_) / 100.0;
+	} else {
+		/*
+		 * The camera sensor gain (g) is usually not equal to the value written
+		 * into the gain register (x). But the way how the AGC algorithm changes
+		 * the gain value to make the total exposure closer to the optimum assumes
+		 * that g(x) is not too far from linear function. If the minimal gain is 0,
+		 * the g(x) is likely to be far from the linear, like g(x) = a / (b * x + c).
+		 * To avoid unexpected changes to the gain by the AGC algorithm (abrupt near
+		 * one edge, and very small near the other) we limit the range of the gain
+		 * values used.
+		 */
+		again_max_ = again_max;
+		if (!again_min) {
+			LOG(IPASoft, Warning) << "Minimum gain is zero, that can't be linear";
+			again_min_ = std::min(100, again_min / 2 + again_max / 2);
+		}
+		againMinStep_ = 1.0;
 	}
 
 	LOG(IPASoft, Info) << "Exposure " << exposure_min_ << "-" << exposure_max_
-			   << ", gain " << again_min_ << "-" << again_max_;
+			   << ", gain " << again_min_ << "-" << again_max_
+			   << " (" << againMinStep_ << ")";
 
 	return 0;
 }
@@ -252,12 +273,14 @@  void IPASoftSimple::processStats(const ControlList &sensorControls)
 	ControlList ctrls(sensorControls);
 
 	exposure_ = ctrls.get(V4L2_CID_EXPOSURE).get<int32_t>();
-	again_ = ctrls.get(V4L2_CID_ANALOGUE_GAIN).get<int32_t>();
+	int32_t again = ctrls.get(V4L2_CID_ANALOGUE_GAIN).get<int32_t>();
+	again_ = camHelper_ ? camHelper_->gain(again) : again;
 
 	updateExposure(exposureMSV);
 
 	ctrls.set(V4L2_CID_EXPOSURE, exposure_);
-	ctrls.set(V4L2_CID_ANALOGUE_GAIN, again_);
+	ctrls.set(V4L2_CID_ANALOGUE_GAIN,
+		  static_cast<int32_t>(camHelper_ ? camHelper_->gainCode(again_) : again_));
 
 	ignore_updates_ = 2;
 
@@ -276,7 +299,7 @@  void IPASoftSimple::updateExposure(double exposureMSV)
 	static constexpr uint8_t kExpNumeratorUp = kExpDenominator + 1;
 	static constexpr uint8_t kExpNumeratorDown = kExpDenominator - 1;
 
-	int next;
+	double next;
 
 	if (exposureMSV < kExposureOptimal - kExposureSatisfactory) {
 		next = exposure_ * kExpNumeratorUp / kExpDenominator;
@@ -286,18 +309,18 @@  void IPASoftSimple::updateExposure(double exposureMSV)
 			exposure_ = next;
 		if (exposure_ >= exposure_max_) {
 			next = again_ * kExpNumeratorUp / kExpDenominator;
-			if (next - again_ < 1)
-				again_ += 1;
+			if (next - again_ < againMinStep_)
+				again_ += againMinStep_;
 			else
 				again_ = next;
 		}
 	}
 
 	if (exposureMSV > kExposureOptimal + kExposureSatisfactory) {
-		if (exposure_ == exposure_max_ && again_ != again_min_) {
+		if (exposure_ == exposure_max_ && again_ > again_min_) {
 			next = again_ * kExpNumeratorDown / kExpDenominator;
-			if (again_ - next < 1)
-				again_ -= 1;
+			if (again_ - next < againMinStep_)
+				again_ -= againMinStep_;
 			else
 				again_ = next;
 		} else {
diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp
index e491ab62..32b56c57 100644
--- a/src/libcamera/pipeline/simple/simple.cpp
+++ b/src/libcamera/pipeline/simple/simple.cpp
@@ -526,7 +526,7 @@  int SimpleCameraData::init()
 	 * Instantiate Soft ISP if this is enabled for the given driver and no converter is used.
 	 */
 	if (!converter_ && pipe->swIspEnabled()) {
-		swIsp_ = std::make_unique<SoftwareIsp>(pipe, sensor_->controls());
+		swIsp_ = std::make_unique<SoftwareIsp>(pipe, sensor_.get());
 		if (!swIsp_->isValid()) {
 			LOG(SimplePipeline, Warning)
 				<< "Failed to create software ISP, disabling software debayering";
diff --git a/src/libcamera/software_isp/software_isp.cpp b/src/libcamera/software_isp/software_isp.cpp
index 9b49be41..ea4d96e4 100644
--- a/src/libcamera/software_isp/software_isp.cpp
+++ b/src/libcamera/software_isp/software_isp.cpp
@@ -60,9 +60,9 @@  LOG_DEFINE_CATEGORY(SoftwareIsp)
 /**
  * \brief Constructs SoftwareIsp object
  * \param[in] pipe The pipeline handler in use
- * \param[in] sensorControls ControlInfoMap describing the controls supported by the sensor
+ * \param[in] sensor Pointer to the CameraSensor instance owned by the pipeline handler
  */
-SoftwareIsp::SoftwareIsp(PipelineHandler *pipe, const ControlInfoMap &sensorControls)
+SoftwareIsp::SoftwareIsp(PipelineHandler *pipe, const CameraSensor *sensor)
 	: debayer_(nullptr),
 	  debayerParams_{ DebayerParams::kGain10, DebayerParams::kGain10, DebayerParams::kGain10, 0.5f, 0 },
 	  dmaHeap_(DmaHeap::DmaHeapFlag::Cma | DmaHeap::DmaHeapFlag::System)
@@ -97,10 +97,10 @@  SoftwareIsp::SoftwareIsp(PipelineHandler *pipe, const ControlInfoMap &sensorCont
 		return;
 	}
 
-	int ret = ipa_->init(IPASettings{ "No cfg file", "No sensor model" },
+	int ret = ipa_->init(IPASettings{ "No cfg file", sensor->model() },
 			     debayer_->getStatsFD(),
 			     sharedParams_.fd(),
-			     sensorControls);
+			     sensor->controls());
 	if (ret) {
 		LOG(SoftwareIsp, Error) << "IPA init failed";
 		debayer_.reset();