[PATCH 3/3] rkisp1: Honor the FrameDurationLimits control

Kieran Bingham kieran.bingham at ideasonboard.com
Mon Oct 14 17:47:47 CEST 2024


From: Paul Elder <paul.elder at ideasonboard.com>

Add support to rkisp1 for controlling the framerate via the
FrameDurationLimits control.

Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---
 src/ipa/rkisp1/algorithms/agc.cpp        | 52 ++++++++++++++++++------
 src/ipa/rkisp1/ipa_context.cpp           | 16 +++++++-
 src/ipa/rkisp1/ipa_context.h             |  4 ++
 src/ipa/rkisp1/rkisp1.cpp                |  2 +
 src/libcamera/pipeline/rkisp1/rkisp1.cpp |  7 ++++
 5 files changed, 68 insertions(+), 13 deletions(-)

diff --git a/src/ipa/rkisp1/algorithms/agc.cpp b/src/ipa/rkisp1/algorithms/agc.cpp
index e23ab120b3e2..088ecf42c480 100644
--- a/src/ipa/rkisp1/algorithms/agc.cpp
+++ b/src/ipa/rkisp1/algorithms/agc.cpp
@@ -180,6 +180,7 @@ int Agc::configure(IPAContext &context, const IPACameraSensorInfo &configInfo)
 
 	/* Limit the frame duration to match current initialisation */
 	ControlInfo &frameDurationLimits = context.ctrlMap[&controls::FrameDurationLimits];
+	context.activeState.agc.minFrameDuration = std::chrono::microseconds(frameDurationLimits.min().get<int64_t>());
 	context.activeState.agc.maxFrameDuration = std::chrono::microseconds(frameDurationLimits.max().get<int64_t>());
 
 	/*
@@ -267,10 +268,21 @@ void Agc::queueRequest(IPAContext &context,
 
 	const auto &frameDurationLimits = controls.get(controls::FrameDurationLimits);
 	if (frameDurationLimits) {
-		utils::Duration maxFrameDuration =
-			std::chrono::milliseconds((*frameDurationLimits).back());
-		agc.maxFrameDuration = maxFrameDuration;
+		/* Limit the control value to the limits in ControlInfo */
+		ControlInfo &limits = context.ctrlMap[&controls::FrameDurationLimits];
+		int64_t minFrameDuration =
+			std::clamp((*frameDurationLimits).front(),
+				   limits.min().get<int64_t>(),
+				   limits.max().get<int64_t>());
+		int64_t maxFrameDuration =
+			std::clamp((*frameDurationLimits).back(),
+				   limits.min().get<int64_t>(),
+				   limits.max().get<int64_t>());
+
+		agc.minFrameDuration = std::chrono::microseconds(minFrameDuration);
+		agc.maxFrameDuration = std::chrono::microseconds(maxFrameDuration);
 	}
+	frameContext.agc.minFrameDuration = agc.minFrameDuration;
 	frameContext.agc.maxFrameDuration = agc.maxFrameDuration;
 }
 
@@ -330,15 +342,8 @@ void Agc::fillMetadata(IPAContext &context, IPAFrameContext &frameContext,
 				     * frameContext.sensor.exposure;
 	metadata.set(controls::AnalogueGain, frameContext.sensor.gain);
 	metadata.set(controls::ExposureTime, exposureTime.get<std::micro>());
+	metadata.set(controls::FrameDuration, frameContext.agc.frameDuration.get<std::micro>());
 	metadata.set(controls::AeEnable, frameContext.agc.autoEnabled);
-
-	/* \todo Use VBlank value calculated from each frame exposure. */
-	uint32_t vTotal = context.configuration.sensor.size.height
-			+ context.configuration.sensor.defVBlank;
-	utils::Duration frameDuration = context.configuration.sensor.lineDuration
-				      * vTotal;
-	metadata.set(controls::FrameDuration, frameDuration.get<std::micro>());
-
 	metadata.set(controls::AeMeteringMode, frameContext.agc.meteringMode);
 	metadata.set(controls::AeExposureMode, frameContext.agc.exposureMode);
 	metadata.set(controls::AeConstraintMode, frameContext.agc.constraintMode);
@@ -400,6 +405,7 @@ void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame,
 		return;
 	}
 
+	IPACameraSensorInfo &sensorInfo = context.sensorInfo;
 	utils::Duration lineDuration = context.configuration.sensor.lineDuration;
 
 	/*
@@ -418,11 +424,19 @@ void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame,
 		       [](uint32_t x) { return x >> 4; });
 	expMeans_ = { params->ae.exp_mean, context.hw->numAeCells };
 
+	/*
+	 * Limit the allowed shutter speeds for the exposure helper based on
+	 * the frame duration limits.
+	 */
+	utils::Duration minShutterSpeed =
+		std::clamp(frameContext.agc.minFrameDuration,
+			   context.configuration.sensor.minShutterSpeed,
+			   context.configuration.sensor.maxShutterSpeed);
 	utils::Duration maxShutterSpeed =
 		std::clamp(frameContext.agc.maxFrameDuration,
 			   context.configuration.sensor.minShutterSpeed,
 			   context.configuration.sensor.maxShutterSpeed);
-	setLimits(context.configuration.sensor.minShutterSpeed,
+	setLimits(minShutterSpeed,
 		  maxShutterSpeed,
 		  context.configuration.sensor.minAnalogueGain,
 		  context.configuration.sensor.maxAnalogueGain);
@@ -451,6 +465,20 @@ void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame,
 	activeState.agc.automatic.exposure = shutterTime / lineDuration;
 	activeState.agc.automatic.gain = aGain;
 
+	/*
+	 * Determine what our FrameDuration must be and adapt VBLANK to suit
+	 * this if we need to expand the shutter time calculated to fill the
+	 * remaining time so that we do not run faster than the minimum frame
+	 * duration (maximum requested frame rate) when we have short exposures.
+	 */
+	utils::Duration frameDuration = std::max(frameContext.agc.minFrameDuration,
+						 shutterTime);
+
+	frameContext.agc.vblank = (frameDuration / lineDuration) - sensorInfo.outputSize.height;
+
+	/* Update accounting for line length quantization. */
+	frameContext.agc.frameDuration = (sensorInfo.outputSize.height + frameContext.agc.vblank) * lineDuration;
+
 	fillMetadata(context, frameContext, metadata);
 	expMeans_ = {};
 }
diff --git a/src/ipa/rkisp1/ipa_context.cpp b/src/ipa/rkisp1/ipa_context.cpp
index 14d0c02a2b32..c5eb0d64ec29 100644
--- a/src/ipa/rkisp1/ipa_context.cpp
+++ b/src/ipa/rkisp1/ipa_context.cpp
@@ -177,6 +177,9 @@ namespace libcamera::ipa::rkisp1 {
  * \var IPAActiveState::agc.meteringMode
  * \brief Metering mode as set by the AeMeteringMode control
  *
+ * \var IPAActiveState::agc.minFrameDuration
+ * \brief Minimum frame duration as set by the FrameDurationLimits control
+ *
  * \var IPAActiveState::agc.maxFrameDuration
  * \brief Maximum frame duration as set by the FrameDurationLimits control
  */
@@ -297,7 +300,9 @@ namespace libcamera::ipa::rkisp1 {
  * \brief Automatic Gain Control parameters for this frame
  *
  * The exposure and gain are provided by the AGC algorithm, and are to be
- * applied to the sensor in order to take effect for this frame.
+ * applied to the sensor in order to take effect for this frame. Additionally
+ * the vertical blanking period is determined to maintain a consistent frame
+ * rate matched to the FrameDurationLimits as set by the user.
  *
  * \var IPAFrameContext::agc.exposure
  * \brief Exposure time expressed as a number of lines computed by the algorithm
@@ -307,6 +312,9 @@ namespace libcamera::ipa::rkisp1 {
  *
  * The gain should be adapted to the sensor specific gain code before applying.
  *
+ * \var IPAFrameContext::agc.vblank
+ * \brief Vertical blanking parameter computed by the algorithm
+ *
  * \var IPAFrameContext::agc.autoEnabled
  * \brief Manual/automatic AGC state as set by the AeEnable control
  *
@@ -319,9 +327,15 @@ namespace libcamera::ipa::rkisp1 {
  * \var IPAFrameContext::agc.meteringMode
  * \brief Metering mode as set by the AeMeteringMode control
  *
+ * \var IPAFrameContext::agc.minFrameDuration
+ * \brief Minimum frame duration as set by the FrameDurationLimits control
+ *
  * \var IPAFrameContext::agc.maxFrameDuration
  * \brief Maximum frame duration as set by the FrameDurationLimits control
  *
+ * \var IPAFrameContext::agc.frameDuration
+ * \brief The actual FrameDuration used by the algorithm for the frame
+ *
  * \var IPAFrameContext::agc.updateMetering
  * \brief Indicate if new ISP AGC metering parameters need to be applied
  */
diff --git a/src/ipa/rkisp1/ipa_context.h b/src/ipa/rkisp1/ipa_context.h
index e274d9b01e1c..60c4d647f1ef 100644
--- a/src/ipa/rkisp1/ipa_context.h
+++ b/src/ipa/rkisp1/ipa_context.h
@@ -79,6 +79,7 @@ struct IPAActiveState {
 		controls::AeConstraintModeEnum constraintMode;
 		controls::AeExposureModeEnum exposureMode;
 		controls::AeMeteringModeEnum meteringMode;
+		utils::Duration minFrameDuration;
 		utils::Duration maxFrameDuration;
 	} agc;
 
@@ -128,11 +129,14 @@ struct IPAFrameContext : public FrameContext {
 	struct {
 		uint32_t exposure;
 		double gain;
+		uint32_t vblank;
 		bool autoEnabled;
 		controls::AeConstraintModeEnum constraintMode;
 		controls::AeExposureModeEnum exposureMode;
 		controls::AeMeteringModeEnum meteringMode;
+		utils::Duration minFrameDuration;
 		utils::Duration maxFrameDuration;
+		utils::Duration frameDuration;
 		bool updateMetering;
 	} agc;
 
diff --git a/src/ipa/rkisp1/rkisp1.cpp b/src/ipa/rkisp1/rkisp1.cpp
index 47777ece783f..17d56fb4e901 100644
--- a/src/ipa/rkisp1/rkisp1.cpp
+++ b/src/ipa/rkisp1/rkisp1.cpp
@@ -449,10 +449,12 @@ void IPARkISP1::setControls(unsigned int frame)
 	IPAFrameContext &frameContext = context_.frameContexts.get(frame);
 	uint32_t exposure = frameContext.agc.exposure;
 	uint32_t gain = context_.camHelper->gainCode(frameContext.agc.gain);
+	uint32_t vblank = frameContext.agc.vblank;
 
 	ControlList ctrls(sensorControls_);
 	ctrls.set(V4L2_CID_EXPOSURE, static_cast<int32_t>(exposure));
 	ctrls.set(V4L2_CID_ANALOGUE_GAIN, static_cast<int32_t>(gain));
+	ctrls.set(V4L2_CID_VBLANK, static_cast<int32_t>(vblank));
 
 	setSensorControls.emit(frame, ctrls);
 }
diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
index 42961c120036..1ec12185bb78 100644
--- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
+++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
@@ -394,6 +394,12 @@ void RkISP1CameraData::paramFilled(unsigned int frame, unsigned int bytesused)
 void RkISP1CameraData::setSensorControls([[maybe_unused]] unsigned int frame,
 					 const ControlList &sensorControls)
 {
+	if (frame == 0) {
+		ControlList controls = sensorControls;
+		sensor_->setControls(&controls);
+		return;
+	}
+
 	delayedCtrls_->push(sensorControls);
 }
 
@@ -1138,6 +1144,7 @@ int PipelineHandlerRkISP1::createCamera(MediaEntity *sensor)
 	std::unordered_map<uint32_t, DelayedControls::ControlParams> params = {
 		{ V4L2_CID_ANALOGUE_GAIN, { 1, false } },
 		{ V4L2_CID_EXPOSURE, { 2, false } },
+		{ V4L2_CID_VBLANK, { 1, false } },
 	};
 
 	data->delayedCtrls_ =
-- 
2.34.1



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