[libcamera-devel] [PATCH 06/13] libcamera: simple: Report sensor timestamp

Jacopo Mondi jacopo at jmondi.org
Mon Apr 19 15:14:26 CEST 2021


Report the sensor's timestamp in the Request metadata using the
completed buffer timestamp.

The buffer's timestamp is recorded at DMA-transfer time, and it does not
theoretically matches the 'start of exposure' definition. Record this with
a \todo entry.

Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
---
 src/libcamera/pipeline/simple/simple.cpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp
index f6095d38e97a..149bd91f1956 100644
--- a/src/libcamera/pipeline/simple/simple.cpp
+++ b/src/libcamera/pipeline/simple/simple.cpp
@@ -22,6 +22,7 @@
 #include <linux/media-bus-format.h>
 
 #include <libcamera/camera.h>
+#include <libcamera/control_ids.h>
 #include <libcamera/request.h>
 #include <libcamera/stream.h>
 
@@ -1134,6 +1135,16 @@ void SimplePipelineHandler::bufferReady(FrameBuffer *buffer)
 
 	/* Otherwise simply complete the request. */
 	Request *request = buffer->request();
+
+	/*
+	 * Record the sensor's timestamp in the request metadata.
+	 *
+	 * \todo The sensor timestamp should be better estimated by connecting
+	 * to the V4L2Device::frameStart signal if the platform provides it.
+	 */
+	request->metadata().set(controls::SensorTimestamp,
+				buffer->metadata().timestamp);
+
 	completeBuffer(request, buffer);
 	completeRequest(request);
 }
-- 
2.31.1



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