[PATCH 1/5] controls: Add FrameWallClock control

[Laurent Pinchart]

Hi David,

Thank you for the patch.

On Fri, Dec 06, 2024 at 02:27:38PM +0000, David Plowman wrote:
> Add a FrameWallClock control that reports the same moment as the
> frame's SensorTimestamp, but in wallclock units.
> 
> Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
> ---
>  src/libcamera/control_ids_core.yaml | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/src/libcamera/control_ids_core.yaml b/src/libcamera/control_ids_core.yaml
> index d45cf8e5..d951b2a3 100644
> --- a/src/libcamera/control_ids_core.yaml
> +++ b/src/libcamera/control_ids_core.yaml
> @@ -971,4 +971,18 @@ controls:
>        description: |
>          Enable or disable the debug metadata.
>  
> +  - FrameWallClock:
> +      type: int64_t
> +      description: |
> +        This timestamp corresponds to the same moment in time as the
> +        SensorTimestamp, but is represented as a wall clock time as measured by
> +        the Linux-specific CLOCK_REALTIME clock id.

s/ id//

CLOCK_REALTIME is not Linux-specific, it's a POSIX clock, so you can
write "by the CLOCK_REALTIME clock".

> +
> +        Being a wall clock measurement, it can be used to synchronise timing
> +        across different devices.
> +
> +        \sa SensorTimestamp
> +
> +        The FrameWallClock control can only be returned in metadata.

Once Paul's ControlId series lands, this sentence should be replaced
with

      direction: out

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> +
>  ...

-- 
Regards,

Laurent Pinchart