[v10,09/11,RESEND] media: v4l2: document the usage of min/max for V4L2_CTRL_TYPE_RECT
Commit Message
Document the default implementation of min/max for rectangle controls.
Signed-off-by: Yunke Cao <yunkec@google.com>
---
Changelog since v9:
- No change.
Changelog since v8:
- New patch.
Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
Comments
On (22/12/01 11:32), Yunke Cao wrote:
> +++ b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst
> @@ -447,7 +447,11 @@ See also the examples in :ref:`control`.
> - n/a
> - A struct :c:type:`v4l2_rect`, containing a rectangle described by
> the position of its top-left corner, the width and the height. Units
> - depend on the use case.
> + depend on the use case. Use ``V4L2_CTRL_WHICH_MIN_VAL`` and
> + ``V4L2_CTRL_WHICH_MAX_VAL`` to query the range of rectangle sizes. The
> + top-left corner of the minimum and maximum rectangles should be the
> + same. For example, a control can have a minimum rectangle of 1x1@0x0 and
> + a maximum of 640x480@0x0.
I assume that examples use width-height@top-left convention. Is this common
or should it be 0x0@1x1 and 0x0@640x480?
Thanks for the review!
On Thu, Dec 1, 2022 at 12:59 PM Sergey Senozhatsky
<senozhatsky@chromium.org> wrote:
>
> On (22/12/01 11:32), Yunke Cao wrote:
> > +++ b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst
> > @@ -447,7 +447,11 @@ See also the examples in :ref:`control`.
> > - n/a
> > - A struct :c:type:`v4l2_rect`, containing a rectangle described by
> > the position of its top-left corner, the width and the height. Units
> > - depend on the use case.
> > + depend on the use case. Use ``V4L2_CTRL_WHICH_MIN_VAL`` and
> > + ``V4L2_CTRL_WHICH_MAX_VAL`` to query the range of rectangle sizes. The
> > + top-left corner of the minimum and maximum rectangles should be the
> > + same. For example, a control can have a minimum rectangle of 1x1@0x0 and
> > + a maximum of 640x480@0x0.
>
> I assume that examples use width-height@top-left convention. Is this common
> or should it be 0x0@1x1 and 0x0@640x480?
It is width-height@left-top. I'm not sure how common it is.
I used the same format in code in patch 01/10, which was suggested by
Hans in a previous version.
case V4L2_CTRL_TYPE_RECT:
pr_cont("%ux%u@%dx%d",
ptr.p_rect->width, ptr.p_rect->height,
ptr.p_rect->left, ptr.p_rect->top);
break;
Let me know if you have any suggestions :) .
Best,
Yunke
@@ -447,7 +447,11 @@ See also the examples in :ref:`control`.
- n/a
- A struct :c:type:`v4l2_rect`, containing a rectangle described by
the position of its top-left corner, the width and the height. Units
- depend on the use case.
+ depend on the use case. Use ``V4L2_CTRL_WHICH_MIN_VAL`` and
+ ``V4L2_CTRL_WHICH_MAX_VAL`` to query the range of rectangle sizes. The
+ top-left corner of the minimum and maximum rectangles should be the
+ same. For example, a control can have a minimum rectangle of 1x1@0x0 and
+ a maximum of 640x480@0x0.
* - ``V4L2_CTRL_TYPE_H264_SPS``
- n/a
- n/a