[libcamera-devel] [PATCH v3 1/4] libcamera: controls: Define size of array controls as a shape vector

[Christian Rauch]

Hi Paul,

Am 20.04.22 um 03:07 schrieb paul.elder at ideasonboard.com:
> Hi Christian,
>
> On Fri, Apr 08, 2022 at 02:42:28AM +0100, Christian Rauch via libcamera-devel wrote:
>> This follows the convention in other Tensor APIs. Since all tensors are
>> represented as a Span with a single dimension, values provided in 'size'
>> are interpreted as fixed-size Spans, while an empty array ("[]") will be
>> interpreted as variable-sized Span.
>
> I see, so you can just chain comma-separated values to add more
> dimensions, neat.
>
> So if you have a variable-length array of objects of size 3 then you'll
> have [3,] ? I suppose it's not that bad.

Spans are 1-dimensional for now and all documented dimensions are
"flattened". Having multiple dimensions is really only useful for
documentation purposes.
Once multidimensional Spans or tensors are supported, their
dimensionality definition could be implemented that way. E.g. "[3,,]"
could be interpreted as a tensor with fixed-size first dimension and
variable-sized second and third dimension.
>
>>
>> Signed-off-by: Christian Rauch <Rauch.Christian at gmx.de>
>
> By the way, you have a Reviewed-by tag from Jacopo on v1.

I am afraid, I don't know how these things work. Do I just copy & paste
this into my commit message or do I have to "import" this reviewed
commit into my branch again?

Best,
Christian
>
>
> Paul
>
>> ---
>>  src/libcamera/control_ids.yaml  | 2 +-
>>  src/libcamera/property_ids.yaml | 4 ++--
>>  2 files changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/src/libcamera/control_ids.yaml b/src/libcamera/control_ids.yaml
>> index 9d4638ae..c3f593a1 100644
>> --- a/src/libcamera/control_ids.yaml
>> +++ b/src/libcamera/control_ids.yaml
>> @@ -291,7 +291,7 @@ controls:
>>          transformation. The 3x3 matrix is stored in conventional reading
>>          order in an array of 9 floating point values.
>>
>> -      size: [3x3]
>> +      size: [3,3]
>>
>>    - ScalerCrop:
>>        type: Rectangle
>> diff --git a/src/libcamera/property_ids.yaml b/src/libcamera/property_ids.yaml
>> index 12ecbce5..47c350ed 100644
>> --- a/src/libcamera/property_ids.yaml
>> +++ b/src/libcamera/property_ids.yaml
>> @@ -497,7 +497,7 @@ controls:
>>
>>    - PixelArrayOpticalBlackRectangles:
>>        type: Rectangle
>> -      size: [n]
>> +      size: []
>>        description: |
>>          The pixel array region(s) which contain optical black pixels
>>          considered valid for calibration purposes.
>> @@ -592,7 +592,7 @@ controls:
>>
>>    - PixelArrayActiveAreas:
>>        type: Rectangle
>> -      size: [n]
>> +      size: []
>>        description: |
>>          The PixelArrayActiveAreas property defines the (possibly multiple and
>>          overlapping) portions of the camera sensor readable pixel matrix
>> --
>> 2.25.1
>>