[libcamera-devel] [PATCH] libcamera: buffer: Improve timestamp documentation

[Kieran Bingham]

The Buffer timestamp documentation is short and does not explain that
the timestamp is based on a monotonic time source, as opposed to the
real/wall-time clocks available in the system.

Expand upon the statements to detail that it can not be used directly as
a wall-clock for the captured date/time without a further reference
point, and that by taking a reference point - the user will be bringing
in potential inconsistencies which must be considered.

Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---
 src/libcamera/buffer.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/libcamera/buffer.cpp b/src/libcamera/buffer.cpp
index a094737d0392..c08ca4234b29 100644
--- a/src/libcamera/buffer.cpp
+++ b/src/libcamera/buffer.cpp
@@ -92,7 +92,13 @@ LOG_DEFINE_CATEGORY(Buffer)
  * The timestamp is expressed as a number of nanoseconds relative to the system
  * clock since an unspecified time point.
  *
- * \todo Be more precise on what timestamps refer to.
+ * This timestamp is monotonic and not affected by changes in system time,
+ * however it is still susceptible to small adjustments made by NTP.
+ *
+ * This clock has no specification on its time base, so can not be directly be
+ * converted to a 'real' wall clock time without a comparable reference point.
+ * However, continued conversions from the reference point, may bring in
+ * inaccuracies due to changes on the real time clock which must be considered.
  */
 
 /**
-- 
2.25.1