[libcamera-devel] [RFC PATCH v4 09/21] android, controls: Add and plumb MaxLatency control

[Jacopo Mondi]

Hi Paul,

On Fri, Jul 16, 2021 at 07:56:19PM +0900, Paul Elder wrote:
> Add a MaxLatency control, and plumb it into the HAL accordingly.
>
> Bug: https://bugs.libcamera.org/show_bug.cgi?id=50
> Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
>
> ---
> Changes in v3:
> - use v3 setMetadata
> - add comment to explain 4
> - remove todo
>
> Changes in v2:
> - use new setMetadata
> - rebase on camera capabilities refactor
> ---
>  src/android/camera_capabilities.cpp |  7 +++++--
>  src/libcamera/control_ids.yaml      | 10 ++++++++++
>  2 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/src/android/camera_capabilities.cpp b/src/android/camera_capabilities.cpp
> index 21e31cf2..c333b329 100644
> --- a/src/android/camera_capabilities.cpp
> +++ b/src/android/camera_capabilities.cpp
> @@ -1127,8 +1127,11 @@ int CameraCapabilities::initializeStaticMetadata()
>  	}
>
>  	/* Sync static metadata. */
> -	int32_t maxLatency = ANDROID_SYNC_MAX_LATENCY_UNKNOWN;
> -	staticMetadata_->addEntry(ANDROID_SYNC_MAX_LATENCY, maxLatency);
> +	setMetadata<int32_t, int32_t>(
> +		staticMetadata_.get(), ANDROID_SYNC_MAX_LATENCY,

As I've read this, I thought if

        staticMetadata->setMetadata()

wouldn't be a nicer API

> +		controlsInfo, &controls::draft::MaxLatency,
> +		ControlRange::Def,

If ::Def serves to get which ControlValue to get from ControlInfo,
can't we pass the ControlValue in directly ?

Anyway, these comments are not on this patch

> +		ANDROID_SYNC_MAX_LATENCY_UNKNOWN);
>
>  	/* Flash static metadata. */
>  	char flashAvailable = ANDROID_FLASH_INFO_AVAILABLE_FALSE;
> diff --git a/src/libcamera/control_ids.yaml b/src/libcamera/control_ids.yaml
> index d92f29f5..9d4638ae 100644
> --- a/src/libcamera/control_ids.yaml
> +++ b/src/libcamera/control_ids.yaml
> @@ -622,6 +622,16 @@ controls:
>          detection, additional format conversions etc) count as an additional
>          pipeline stage.
>
> +  - MaxLatency:
> +      type: int32_t
> +      draft: true
> +      description: |
> +        The maximum number of frames that can occur after a request (different
> +        than the previous) has been submitted, and before the result's state
> +        becomes synchronized. A value of -1 indicates unknown latency, and 0
> +        indicates per-frame control. Currently identical to
> +        ANDROID_SYNC_MAX_LATENCY.
> +

Do we have a sorting order for controls ? It seems we don't...
Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>

Thanks
   j

>    - TestPatternMode:
>        type: int32_t
>        draft: true
> --
> 2.27.0
>