[libcamera-devel] Mandatory camera properties

[Kieran Bingham]

Hi Niklas, Laurent,

On 20/08/2020 12:02, Laurent Pinchart wrote:
> Hi Niklas,
> 
> On Thu, Aug 20, 2020 at 09:23:20AM +0200, Niklas Söderlund wrote:
>> Hello,
>>
>> While reading the hot-plug series and with my recent work on 
>> user-friendly names discussions on camera properties have been touch 
>> upon. Before working on adding a check to disallow registering a camera 
>> that does not have all these properties I think it's a good idea we 
>> agree on which ones are mandatory.
>>
>> After reading the current discussions and whats in master it seems we 
>> wish to make Location but not Rotation mandatory, is this correct? If so 
>> shall we remove the Rotation fallback (set to 0) in CameraSensor?
> 
> Rotation shouldn't be mandatory, as it's meaningless for external
> cameras for instance. I wonder if we shouldn't make it mandatory for
> internal cameras though.
> 
>> Looking a head I thin we also would like to make the (hopefully) 
>> upcoming Model property mandatory?
>>
>> I see no urgency to lock this all down but as we move to do more work 
>> involving properties I think its time we start to think about if we want 
>> to make some of them mandatory.
> 
> Yes, this is needed. Should we add a required property to the YAML files
> to denote this ?

A property in the YAML file sounds like a good idea to denote what
'must' be set, but how would we enforce it? I assume that would then
need to be part of an external camera/pipeline validation tool?

(of course such tool could parse the mandatory properties list and 'get'
them, and fail if it can't so it is indeed useful as a property in the
yaml definitions.)


-- 
Regards
--
Kieran