[libcamera-devel] [PATCH v2 1/4] ipa: ipu3: Separate out frame context queue as a distinct class

[Umang Jain]

There are cases where we need more checks and balance to be carried out
by the frame context queue class. For that, separate it out as a
distinct class on which we can build upon.

For now, a minimialistic implementation is provided with .get(frame)
helper which returns a IPAFrameContext pointer for the required frame.
Going ahead FCQueue::get() can be extended to access/modify the frame
context queue.

Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder at ideasonboard.com>
Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois at ideasonboard.com>
---
 src/ipa/ipu3/ipa_context.cpp | 65 ++++++++++++++++++++++++++++++++++--
 src/ipa/ipu3/ipa_context.h   | 13 +++++++-
 src/ipa/ipu3/ipu3.cpp        | 18 +++++-----
 3 files changed, 84 insertions(+), 12 deletions(-)

diff --git a/src/ipa/ipu3/ipa_context.cpp b/src/ipa/ipu3/ipa_context.cpp
index 13cdb835..36d20b1b 100644
--- a/src/ipa/ipu3/ipa_context.cpp
+++ b/src/ipa/ipu3/ipa_context.cpp
@@ -7,12 +7,18 @@
 
 #include "ipa_context.h"
 
+#include <libcamera/base/log.h>
+
 /**
  * \file ipa_context.h
  * \brief Context and state information shared between the algorithms
  */
 
-namespace libcamera::ipa::ipu3 {
+namespace libcamera {
+
+LOG_DECLARE_CATEGORY(IPAIPU3)
+
+namespace ipa::ipu3 {
 
 /**
  * \struct IPASessionConfiguration
@@ -211,4 +217,59 @@ IPAFrameContext::IPAFrameContext(uint32_t id, const ControlList &reqControls)
  * \brief Analogue gain multiplier
  */
 
-} /* namespace libcamera::ipa::ipu3 */
+/**
+ * \class FCQueue
+ * \brief A FIFO circular queue holding IPAFrameContext(s)
+ *
+ * FCQueue holds all the IPAFrameContext(s) related to frames required
+ * to be processed by the IPA at a given point.
+ */
+
+/**
+ * \brief FCQueue constructor
+ */
+FCQueue::FCQueue()
+{
+	reset();
+}
+
+/**
+ * \brief Retrieve the IPAFrameContext for the frame
+ * \param[in] frame Frame number for which the IPAFrameContext needs to
+ * retrieved
+ *
+ * \return Pointer to the IPAFrameContext
+ */
+IPAFrameContext *FCQueue::get(uint32_t frame)
+{
+	IPAFrameContext &frameContext = this->at(frame % kMaxFrameContexts);
+
+	if (frame != frameContext.frame) {
+		LOG(IPAIPU3, Warning)
+			<< "Got wrong frame context for frame" << frame
+			<< " or frame context doesn't exist yet";
+	}
+
+	return &frameContext;
+}
+
+/**
+ * \brief Sets the size of the FCQueue
+ * \param[in] size The intended size of the FCQueue
+ */
+void FCQueue::setSize(uint32_t size)
+{
+	resize(size);
+}
+
+/**
+ * \brief Clear the FCQueue by resetting all the entries in the ring-buffer
+ */
+void FCQueue::reset()
+{
+	clear();
+}
+
+} /* namespace ipa::ipu3 */
+
+} /* namespace libcamera */
diff --git a/src/ipa/ipu3/ipa_context.h b/src/ipa/ipu3/ipa_context.h
index 42e11141..e487d34b 100644
--- a/src/ipa/ipu3/ipa_context.h
+++ b/src/ipa/ipu3/ipa_context.h
@@ -89,11 +89,22 @@ struct IPAFrameContext {
 	ControlList frameControls;
 };
 
+class FCQueue : public std::vector<IPAFrameContext>
+{
+public:
+	FCQueue();
+
+	void reset();
+	void setSize(uint32_t size);
+
+	IPAFrameContext *get(uint32_t frame);
+};
+
 struct IPAContext {
 	IPASessionConfiguration configuration;
 	IPAActiveState activeState;
 
-	std::array<IPAFrameContext, kMaxFrameContexts> frameContexts;
+	FCQueue frameContexts;
 };
 
 } /* namespace ipa::ipu3 */
diff --git a/src/ipa/ipu3/ipu3.cpp b/src/ipa/ipu3/ipu3.cpp
index 2f6bb672..d770c254 100644
--- a/src/ipa/ipu3/ipu3.cpp
+++ b/src/ipa/ipu3/ipu3.cpp
@@ -456,8 +456,8 @@ int IPAIPU3::configure(const IPAConfigInfo &configInfo,
 
 	/* Clean IPAActiveState at each reconfiguration. */
 	context_.activeState = {};
-	IPAFrameContext initFrameContext;
-	context_.frameContexts.fill(initFrameContext);
+	context_.frameContexts.reset();
+	context_.frameContexts.setSize(kMaxFrameContexts);
 
 	if (!validateSensorControls()) {
 		LOG(IPAIPU3, Error) << "Sensor control validation failed.";
@@ -569,20 +569,20 @@ void IPAIPU3::processStatsBuffer(const uint32_t frame,
 	const ipu3_uapi_stats_3a *stats =
 		reinterpret_cast<ipu3_uapi_stats_3a *>(mem.data());
 
-	IPAFrameContext &frameContext = context_.frameContexts[frame % kMaxFrameContexts];
+	IPAFrameContext *frameContext = context_.frameContexts.get(frame);
 
-	if (frameContext.frame != frame)
+	if (frameContext->frame != frame)
 		LOG(IPAIPU3, Warning) << "Frame " << frame << " does not match its frame context";
 
-	frameContext.sensor.exposure = sensorControls.get(V4L2_CID_EXPOSURE).get<int32_t>();
-	frameContext.sensor.gain = camHelper_->gain(sensorControls.get(V4L2_CID_ANALOGUE_GAIN).get<int32_t>());
+	frameContext->sensor.exposure = sensorControls.get(V4L2_CID_EXPOSURE).get<int32_t>();
+	frameContext->sensor.gain = camHelper_->gain(sensorControls.get(V4L2_CID_ANALOGUE_GAIN).get<int32_t>());
 
 	double lineDuration = context_.configuration.sensor.lineDuration.get<std::micro>();
 	int32_t vBlank = context_.configuration.sensor.defVBlank;
 	ControlList ctrls(controls::controls);
 
 	for (auto const &algo : algorithms_)
-		algo->process(context_, &frameContext, stats);
+		algo->process(context_, frameContext, stats);
 
 	setControls(frame);
 
@@ -590,11 +590,11 @@ void IPAIPU3::processStatsBuffer(const uint32_t frame,
 	int64_t frameDuration = (vBlank + sensorInfo_.outputSize.height) * lineDuration;
 	ctrls.set(controls::FrameDuration, frameDuration);
 
-	ctrls.set(controls::AnalogueGain, frameContext.sensor.gain);
+	ctrls.set(controls::AnalogueGain, frameContext->sensor.gain);
 
 	ctrls.set(controls::ColourTemperature, context_.activeState.awb.temperatureK);
 
-	ctrls.set(controls::ExposureTime, frameContext.sensor.exposure * lineDuration);
+	ctrls.set(controls::ExposureTime, frameContext->sensor.exposure * lineDuration);
 
 	/*
 	 * \todo The Metadata provides a path to getting extended data
-- 
2.31.1