lkml.org 
[lkml]   [2023]   [Aug]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC PATCH 0/2] media: v4l2: map UVC_CT_ROLL_ABSOLUTE_CONTROL
From
Date
Hi Michael,

On Fri, 2023-08-04 at 20:45 +0200, Michael Riesch wrote:
> Hi Gergő,
>
> Interesting work! I would guess that there are a lot of cameras with an
> accelerometer or gyroscope that could report the rotation.
>

I think only the Streamcam in the UVC world, but who knows. :)

> On 8/3/23 23:28, Gergő Köteles wrote:
> > Hi,
> >
> > Logitech Streamcam can be mounted in 'portrait mode' as well.
> > It reports the current roll (-90, 0, 90, 180) with
> > UVC_CT_ROLL_ABSOLUTE_CONTROL.
> >
> > This RFC defines V4L2_CID_ROLL_ABSOLUTE, and maps
> > UVC_CT_ROLL_ABSOLUTE_CONTROL to make it available to
> > userspace.
> > Then, the userspace can rotate the stream based on the roll.
>
> Should we also discuss pitch and yaw while we are at it?
>

They are there with V4L2_CID_PAN_ABSOLUTE and V4L2_CID_TILT_ABSOLUTE.

> As far as I know there are controls to set pan and tilt of a PTZ camera,
> but there are no controls that report those angles.
>

Aren't real PTZ cameras using the CT_PANTILT_ABSOLUTE_CONTROL for
panning and tilting? Or just to move the crop window?

> > Is it better to use V4L2_CID_CAMERA_SENSOR_ROTATION for this?
>
> IMHO that would make sense.
>
> Best regards,
> Michael
>
> > The value set matches that control.
> > If yes, is it worth mapping UVC_CT_ROLL_ABSOLUTE_CONTROL to
> > V4L2_CID_CAMERA_SENSOR_ROTATION for this camera only?
> >
> > Any feedback is greately appreciated.
> >
> >
> > Gergő Köteles (2):
> > media: v4l2: ctrls: Add ROLL_ABSOLUTE control
> > media: v4l2: map UVC_CT_ROLL_ABSOLUTE_CONTROL
> >
> > .../userspace-api/media/v4l/ext-ctrls-camera.rst | 5 +++++
> > drivers/media/usb/uvc/uvc_ctrl.c | 9 +++++++++
> > drivers/media/v4l2-core/v4l2-ctrls-defs.c | 1 +
> > include/uapi/linux/v4l2-controls.h | 2 ++
> > 4 files changed, 17 insertions(+)
> >
> >
> > base-commit: 06c2afb862f9da8dc5efa4b6076a0e48c3fbaaa5

\
 
 \ /
  Last update: 2023-08-04 23:34    [W:0.029 / U:1.244 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site