[PATCH v4 4/7] pipeline: rpi: common: Add wallclock timestamp support

[David Plowman]

A ClockRecovery object is added for derived classes to use, and
wallclock timestamps are copied into the request metadata for
applications.

Wallclock timestamps are derived corresponding to the sensor
timestamp, and made available to the base pipeline handler class and
to IPAs.

Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
Reviewed-by: Naushir Patuck <naush at raspberrypi.com>
---
 src/libcamera/pipeline/rpi/common/pipeline_base.cpp |  5 +++++
 src/libcamera/pipeline/rpi/common/pipeline_base.h   |  3 +++
 src/libcamera/pipeline/rpi/vc4/vc4.cpp              | 10 ++++++++--
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/libcamera/pipeline/rpi/common/pipeline_base.cpp b/src/libcamera/pipeline/rpi/common/pipeline_base.cpp
index 4b147fdb..56f3c4df 100644
--- a/src/libcamera/pipeline/rpi/common/pipeline_base.cpp
+++ b/src/libcamera/pipeline/rpi/common/pipeline_base.cpp
@@ -686,6 +686,9 @@ int PipelineHandlerBase::start(Camera *camera, const ControlList *controls)
 		return ret;
 	}
 
+	/* A good moment to add an initial clock sample. */
+	data->wallClockRecovery_.addSample();
+
 	/*
 	 * Reset the delayed controls with the gain and exposure values set by
 	 * the IPA.
@@ -1510,6 +1513,8 @@ void CameraData::fillRequestMetadata(const ControlList &bufferControls, Request
 {
 	request->metadata().set(controls::SensorTimestamp,
 				bufferControls.get(controls::SensorTimestamp).value_or(0));
+	request->metadata().set(controls::FrameWallClock,
+				bufferControls.get(controls::FrameWallClock).value_or(0));
 
 	if (cropParams_.size()) {
 		std::vector<Rectangle> crops;
diff --git a/src/libcamera/pipeline/rpi/common/pipeline_base.h b/src/libcamera/pipeline/rpi/common/pipeline_base.h
index aae0c2f3..ca706bf3 100644
--- a/src/libcamera/pipeline/rpi/common/pipeline_base.h
+++ b/src/libcamera/pipeline/rpi/common/pipeline_base.h
@@ -20,6 +20,7 @@
 #include "libcamera/internal/bayer_format.h"
 #include "libcamera/internal/camera.h"
 #include "libcamera/internal/camera_sensor.h"
+#include "libcamera/internal/clock_recovery.h"
 #include "libcamera/internal/framebuffer.h"
 #include "libcamera/internal/media_device.h"
 #include "libcamera/internal/media_object.h"
@@ -177,6 +178,8 @@ public:
 
 	Config config_;
 
+	ClockRecovery wallClockRecovery_;
+
 protected:
 	void fillRequestMetadata(const ControlList &bufferControls,
 				 Request *request);
diff --git a/src/libcamera/pipeline/rpi/vc4/vc4.cpp b/src/libcamera/pipeline/rpi/vc4/vc4.cpp
index fd8d84b1..3d8c65c6 100644
--- a/src/libcamera/pipeline/rpi/vc4/vc4.cpp
+++ b/src/libcamera/pipeline/rpi/vc4/vc4.cpp
@@ -781,9 +781,15 @@ void Vc4CameraData::unicamBufferDequeue(FrameBuffer *buffer)
 		auto [ctrl, delayContext] = delayedCtrls_->get(buffer->metadata().sequence);
 		/*
 		 * Add the frame timestamp to the ControlList for the IPA to use
-		 * as it does not receive the FrameBuffer object.
+		 * as it does not receive the FrameBuffer object. Also derive a
+		 * corresponding wallclock value.
 		 */
-		ctrl.set(controls::SensorTimestamp, buffer->metadata().timestamp);
+		wallClockRecovery_.addSample();
+		uint64_t sensorTimestamp = buffer->metadata().timestamp;
+		uint64_t wallClockTimestamp = wallClockRecovery_.getOutput(sensorTimestamp / 1000);
+
+		ctrl.set(controls::SensorTimestamp, sensorTimestamp);
+		ctrl.set(controls::FrameWallClock, wallClockTimestamp);
 		bayerQueue_.push({ buffer, std::move(ctrl), delayContext });
 	} else {
 		embeddedQueue_.push(buffer);
-- 
2.39.5