pipeline: rpi: Add wallclock timestamp support

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, for both vc4 and pisp platforms.

Signed-off-by: David Plowman <david.plowman@raspberrypi.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Naushir Patuck <naush@raspberrypi.com>
Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/libcamera/pipeline/rpi/common/pipeline_base.cpp

@@ -685,6 +685,9 @@ 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.
@@ -1482,6 +1485,8 @@ 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;

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"
@@ -172,6 +173,8 @@ public:
 
 	Config config_;
 
+	ClockRecovery wallClockRecovery_;
+
 protected:
 	void fillRequestMetadata(const ControlList &bufferControls,
 				 Request *request);

src/libcamera/pipeline/rpi/pisp/pisp.cpp

@@ -1755,9 +1755,15 @@ void PiSPCameraData::cfeBufferDequeue(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);
 		job.sensorControls = std::move(ctrl);
 		job.delayContext = delayContext;
 	} else if (stream == &cfe_[Cfe::Config]) {

src/libcamera/pipeline/rpi/vc4/vc4.cpp

@@ -773,9 +773,15 @@ 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);