Re: [PATCH v16 18/18] media: uvcvideo: document UVC v1.5 ROI

[Hans de Goede]

Hi,

On 10-Dec-24 10:42 AM, Ricardo Ribalda wrote:
> From: Yunke Cao <yunkec@xxxxxxxxxx>
> 
> Added documentation of V4L2_CID_UVC_REGION_OF_INTEREST_RECT and
> V4L2_CID_UVC_REGION_OF_INTEREST_AUTO.
> 
> An example of a userspace implementing this feature can be found at:
> https://chromium.googlesource.com/chromiumos/platform2/+/refs/heads/release-R121-15699.B/camera/hal/usb/
> 
> Reviewed-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> Reviewed-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
> Signed-off-by: Yunke Cao <yunkec@xxxxxxxxxx>
> Tested-by: Yunke Cao <yunkec@xxxxxxxxxx>
> Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>

Thanks, new version looks good to me:

Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>

Regards,

Hans


> ---
>  .../userspace-api/media/drivers/uvcvideo.rst       | 64 ++++++++++++++++++++++
>  1 file changed, 64 insertions(+)
> 
> diff --git a/Documentation/userspace-api/media/drivers/uvcvideo.rst b/Documentation/userspace-api/media/drivers/uvcvideo.rst
> index a290f9fadae9..dbb30ad389ae 100644
> --- a/Documentation/userspace-api/media/drivers/uvcvideo.rst
> +++ b/Documentation/userspace-api/media/drivers/uvcvideo.rst
> @@ -181,6 +181,7 @@ Argument: struct uvc_xu_control_mapping
>  	UVC_CTRL_DATA_TYPE_BOOLEAN	Boolean
>  	UVC_CTRL_DATA_TYPE_ENUM		Enumeration
>  	UVC_CTRL_DATA_TYPE_BITMASK	Bitmask
> +	UVC_CTRL_DATA_TYPE_RECT		Rectangular area
>  
>  
>  UVCIOC_CTRL_QUERY - Query a UVC XU control
> @@ -255,3 +256,66 @@ Argument: struct uvc_xu_control_query
>  	__u8	query		Request code to send to the device
>  	__u16	size		Control data size (in bytes)
>  	__u8	*data		Control value
> +
> +
> +Driver-specific V4L2 controls
> +-----------------------------
> +
> +The uvcvideo driver implements the following UVC-specific controls:
> +
> +``V4L2_CID_UVC_REGION_OF_INTEREST_RECT (struct)``
> +	This control determines the region of interest (ROI). ROI is a
> +	rectangular area represented by a struct :c:type:`v4l2_rect`. The
> +	rectangle is in global sensor coordinates using pixel units. It is
> +	independent of the field of view, not impacted by any cropping or
> +	scaling.
> +
> +	Use ``V4L2_CTRL_WHICH_MIN_VAL`` and ``V4L2_CTRL_WHICH_MAX_VAL`` to query
> +	the range of rectangle sizes.
> +
> +	Setting a ROI allows the camera to optimize the capture for the region.
> +	The value of ``V4L2_CID_REGION_OF_INTEREST_AUTO`` control determines
> +	the detailed behavior.
> +
> +	An example of use of this control, can be found in the:
> +	`Chrome OS USB camera HAL.
> +	<https://chromium.googlesource.com/chromiumos/platform2/+/refs/heads/release-R121-15699.B/camera/hal/usb/>`
> +
> +
> +``V4L2_CID_UVC_REGION_OF_INTEREST_AUTO (bitmask)``
> +	This determines which, if any, on-board features should track to the
> +	Region of Interest specified by the current value of
> +	``V4L2_CID_UVD__REGION_OF_INTEREST_RECT``.
> +
> +	Max value is a mask indicating all supported Auto Controls.
> +
> +.. flat-table::
> +    :header-rows:  0
> +    :stub-columns: 0
> +
> +    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_EXPOSURE``
> +      - Setting this bit causes automatic exposure to track the region of
> +	interest instead of the whole image.
> +    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_IRIS``
> +      - Setting this bit causes automatic iris to track the region of interest
> +        instead of the whole image.
> +    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_WHITE_BALANCE``
> +      - Setting this bit causes automatic white balance to track the region
> +	of interest instead of the whole image.
> +    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_FOCUS``
> +      - Setting this bit causes automatic focus adjustment to track the region
> +        of interest instead of the whole image.
> +    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_FACE_DETECT``
> +      - Setting this bit causes automatic face detection to track the region of
> +        interest instead of the whole image.
> +    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_DETECT_AND_TRACK``
> +      - Setting this bit enables automatic face detection and tracking. The
> +	current value of ``V4L2_CID_REGION_OF_INTEREST_RECT`` may be updated by
> +	the driver.
> +    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_IMAGE_STABILIZATION``
> +      - Setting this bit enables automatic image stabilization. The
> +	current value of ``V4L2_CID_REGION_OF_INTEREST_RECT`` may be updated by
> +	the driver.
> +    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_HIGHER_QUALITY``
> +      - Setting this bit enables automatically capture the specified region
> +        with higher quality if possible.
>