Hi Ricardo,
On 14-Nov-24 9:03 PM, Ricardo Ribalda wrote:
> Hi Gergo
>
> Sorry, I forgot to reply to your comment in v14.
>
> On Thu, 14 Nov 2024 at 20:53, Gergo Koteles <soyer@xxxxxx> wrote:
>>
>> Hi Ricardo,
>>
>> On Thu, 2024-11-14 at 19:10 +0000, Ricardo Ribalda wrote:
>>>
>>> + },
>>> + {
>>> + .id = V4L2_CID_UVC_REGION_OF_INTEREST_AUTO,
>>> + .entity = UVC_GUID_UVC_CAMERA,
>>> + .selector = UVC_CT_REGION_OF_INTEREST_CONTROL,
>>> + .size = 16,
>>> + .offset = 64,
>>> + .v4l2_type = V4L2_CTRL_TYPE_BITMASK,
>>> + .data_type = UVC_CTRL_DATA_TYPE_BITMASK,
>>> + .name = "Region Of Interest Auto Controls",
>>> + },
>>> };
>>>
>>
>> Wouldn't be better to use 8 V4L2_CTRL_TYPE_BOOLEAN controls for this?
>
> If I create 8 Booleans, they will always be shown in the device. And
> the user will not have a way to know which values are available and
> which are not.
>
> We will also fail the v4l2-compliance test, because there will be up
> to 7 boolean controls that will not be able to be set to 1, eventhough
> they are writable.
So why can't these other controls be set to 1? Because only one
of the options in the bitmask can be selected at a time ?
If only 1 bit in the UVC_CTRL_DATA_TYPE_BITMASK for this can be one
at the time, then this should be mapped to a V4L2_CTRL_TYPE_MENU
just like how that is done for V4L2_CID_EXPOSURE_AUTO already.
Actually looking at existing comments about UVC_CTRL_DATA_TYPE_BITMASK
in the driver there is this comment on top of uvc_mapping_get_menu_value()
* For controls of type UVC_CTRL_DATA_TYPE_BITMASK, the UVC control value is
* expressed as a bitmask and is thus guaranteed to have a single bit set.
Assuming this "guaranteed to have a single bit set" comment is valid for
the V4L2_CID_UVC_REGION_OF_INTEREST_AUTO part of UVC_CT_REGION_OF_INTEREST_CONTROL
too then I think we should simply map this to a menu similar to how
this is done for V4L2_CID_EXPOSURE_AUTO.
Note V4L2_CID_EXPOSURE_AUTO is the only existing user of UVC_CTRL_DATA_TYPE_BITMASK
at the moment.
Mapping this to a menu should nicely address Gergo's concerns here.
Regards,
Hans
