[libcamera-devel] [PATCH 1/1] libcamera: controls: Add StartupFrame control

[Naushir Patuck]

Hi David,

Thank you for this patch.  Indeed removing the drop frame logic the pipeline
handler would simplify things!

On Wed, 31 May 2023 at 13:50, David Plowman via libcamera-devel
<libcamera-devel at lists.libcamera.org> wrote:
>
> This control is passed back in a frame as metadata to indicate whether
> the camera system is still in a startup phase, and the application is
> advised to avoid using the frame.
>
> Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
> ---
>  src/libcamera/control_ids.yaml | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>
> diff --git a/src/libcamera/control_ids.yaml b/src/libcamera/control_ids.yaml
> index adea5f90..4742d907 100644
> --- a/src/libcamera/control_ids.yaml
> +++ b/src/libcamera/control_ids.yaml
> @@ -694,6 +694,21 @@ controls:
>              Continuous AF is paused. No further state changes or lens movements
>              will occur until the AfPauseResume control is sent.
>
> +  - StartupFrame:
> +      type: bool
> +      description: |
> +        The value true indicates that the camera system is still in a startup
> +        phase where the output images may not be reliable, or that certain of
> +        the control algorithms (such as AEC/AGC, AWB, and possibly others) may
> +        still be changing quite rapidly.
> +
> +        Applications are advised to avoid using these frames. Mostly, they will
> +        occur when the camera system starts for the first time, although,
> +        depending on the sensor and the implementation, they could occur at
> +        other times.
> +
> +        The value false indicates that this is a normal frame.

Just throwing it out there, but would it be useful if this control was an
integer with the count of startup frames left to handle? A value of 0, or the
absence of the control would indicate this is a "valid" frame.

Regards,
Naush

> +
>    # ----------------------------------------------------------------------------
>    # Draft controls section
>
> --
> 2.30.2
>