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.
Is it better to use V4L2_CID_CAMERA_SENSOR_ROTATION for this?
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
--
2.41.0
Add V4L2_CID_ROLL_ABSOLUTE as an integer control to
retrieve and set the camera roll in degrees, and its
documentation.
Signed-off-by: Gergő Köteles <[email protected]>
---
Documentation/userspace-api/media/v4l/ext-ctrls-camera.rst | 5 +++++
drivers/media/v4l2-core/v4l2-ctrls-defs.c | 1 +
include/uapi/linux/v4l2-controls.h | 2 ++
3 files changed, 8 insertions(+)
diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-camera.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-camera.rst
index cdc515c60468..81bc31a4bf79 100644
--- a/Documentation/userspace-api/media/v4l/ext-ctrls-camera.rst
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-camera.rst
@@ -672,3 +672,8 @@ enum v4l2_scene_mode -
As modes differ for each sensor, menu items are not standardized by this
control and are left to the programmer.
+
+``V4L2_CID_ROLL_ABSOLUTE (integer)``
+ This control describes the camera rotation along the image viewing axis in
+ degrees. Values range from -180 to +180, the default is zero. Positive
+ values rotate the camera clockwise, negative values counter-clockwise.
diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
index 8696eb1cdd61..0e8af56cb2a2 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
@@ -1086,6 +1086,7 @@ const char *v4l2_ctrl_get_name(u32 id)
case V4L2_CID_CAMERA_ORIENTATION: return "Camera Orientation";
case V4L2_CID_CAMERA_SENSOR_ROTATION: return "Camera Sensor Rotation";
case V4L2_CID_HDR_SENSOR_MODE: return "HDR Sensor Mode";
+ case V4L2_CID_ROLL_ABSOLUTE: return "Roll, Absolute";
/* FM Radio Modulator controls */
/* Keep the order of the 'case's the same as in v4l2-controls.h! */
diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index c3604a0a3e30..5131711ea873 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -1075,6 +1075,8 @@ enum v4l2_auto_focus_range {
#define V4L2_CID_HDR_SENSOR_MODE (V4L2_CID_CAMERA_CLASS_BASE+36)
+#define V4L2_CID_ROLL_ABSOLUTE (V4L2_CID_CAMERA_CLASS_BASE+37)
+
/* FM Modulator class control IDs */
#define V4L2_CID_FM_TX_CLASS_BASE (V4L2_CTRL_CLASS_FM_TX | 0x900)
--
2.41.0
Hi Gergő,
Interesting work! I would guess that there are a lot of cameras with an
accelerometer or gyroscope that could report the rotation.
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?
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.
> 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
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