Re: [PATCH v7 7/7] media: uvcvideo: document UVC v1.5 ROI

Ricardo Ribalda
2022-06-30T06:41:56Z

On Tue, 28 Jun 2022 at 09:58, Yunke Cao <yunkec@google.com> wrote:
>
> Added documentation of V4L2_CID_UVC_REGION_OF_INTEREST_RECT and
> V4L2_CID_UVC_REGION_OF_INTEREST_AUTO.
>
> Signed-off-by: Yunke Cao <yunkec@google.com>
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
> .../userspace-api/media/drivers/uvcvideo.rst | 61 +++++++++++++++++++
> 1 file changed, 61 insertions(+)
>
> diff --git a/Documentation/userspace-api/media/drivers/uvcvideo.rst b/Documentation/userspace-api/media/drivers/uvcvideo.rst
> index a290f9fadae9..ee4c182aa274 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 +256,63 @@ 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
> +
> +Private V4L2 controls
> +---------------------
> +
> +A few UVC specific V4L2 control IDs are listed below.
> +
> +``V4L2_CID_UVC_REGION_OF_INTEREST_RECT (struct)``
> + This control determines the region of interest (ROI). ROI is an
> + rectangular area represented by a struct :c:type:`v4l2_rect`. The
> + rectangle is in global sensor coordinates and 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. For example, a device can have a minimum
> + ROI rectangle of 1x1@0x0 and a maximum of 640x480@0x0.
> +
> + 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.
> +
> +
> +``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_REGION_OF_INTEREST_AUTO_EXPOSURE``
> + - Setting this to true enables automatic exposure time for the specified
> + region.
> + * - ``V4L2_REGION_OF_INTEREST_AUTO_IRIS``
> + - Setting this to true enables automatic iris aperture for the specified
> + region.
> + * - ``V4L2_REGION_OF_INTEREST_AUTO_WHITE_BALANCE``
> + - Setting this to true enables automatic white balance adjustment for the
> + specified region.
> + * - ``V4L2_REGION_OF_INTEREST_AUTO_FOCUS``
> + - Setting this to true enables automatic focus adjustment for the
> + specified region.
> + * - ``V4L2_REGION_OF_INTEREST_AUTO_FACE_DETECT``
> + - Setting this to true enables automatic face detection for the
> + specified region.
> + * - ``V4L2_REGION_OF_INTEREST_AUTO_DETECT_AND_TRACK``
> + - Setting this to true enables automatic face detection and tracking. The
> + current value of ``V4L2_CID_REGION_OF_INTEREST_RECT`` may be updated by
> + the driver.
> + * - ``V4L2_REGION_OF_INTEREST_AUTO_IMAGE_STABILIZATION``
> + - Setting this to true enables automatic image stabilization. The
> + current value of ``V4L2_CID_REGION_OF_INTEREST_RECT`` may be updated by
> + the driver.
> + * - ``V4L2_REGION_OF_INTEREST_AUTO_HIGHER_QUALITY``
> + - Setting this to true enables automatically capture the specified region
> + with higher quality if possible.
> --
> 2.37.0.rc0.161.g10f37bed90-goog
>

--
Ricardo Ribalda