libcamera: controls: Use std::optional to handle invalid control values

Previously, ControlList::get<T>() would use default constructed objects to
indicate that a ControlList does not have the requested Control. This has
several disadvantages: 1) It requires types to be default constructible,
2) it does not differentiate between a default constructed object and an
object that happens to have the same state as a default constructed object.

std::optional<T> additionally stores the information if the object is valid
or not, and therefore is more expressive than a default constructed object.

Signed-off-by: Christian Rauch <Rauch.Christian@gmx.de>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp
index a7a0c440..3d3efc0c 100644
--- a/src/gstreamer/gstlibcamerasrc.cpp
+++ b/src/gstreamer/gstlibcamerasrc.cpp
@@ -234,7 +234,7 @@ GstLibcameraSrcState::requestCompleted(Request *request)
 	}
 
 	if (GST_ELEMENT_CLOCK(src_)) {
-		int64_t timestamp = request->metadata().get(controls::SensorTimestamp);
+		int64_t timestamp = request->metadata().get(controls::SensorTimestamp).value_or(0);
 
 		GstClockTime gst_base_time = GST_ELEMENT(src_)->base_time;
 		GstClockTime gst_now = gst_clock_get_time(GST_ELEMENT_CLOCK(src_));