[libcamera-devel] [PATCH v4 0/4] Raspberry Pi: handle sensors more flexibly

[Kieran Bingham]

Hi David,

On 27/04/2021 14:08, David Plowman wrote:
> Hi
> 
> Here's a version 4 of this patch set. The only difference over v3 is a
> new penultimate patch that adds new V4L2 controls for informing the
> sensor of the colour gains.
> 
> I've actually added a control for each of the 4 Bayer colour channels
> even though I use only two of them. It feels like one of those things
> where some sensor may eventually want the ones that I might have been
> tempted to miss out, at which point why not just include them? Though
> I still wonder if having both GREENR and GREENB is overkill, and just
> GREEN would have sufficed. Any thoughts on that?

I think adding them all in now makes more sense than adding some in now,
and then finding the others are needed but the numbering is no longer
consecutive because a control has been added in the meanwhile.

Would there ever be a (non-bayer?) sensor that would use only R,G,B? In
which case, I would wonder which GREEN should be used... but I suspect
that's not really an issue that will occur if sensors that need this
data are always going to be some form of bayer.


> Once we're happy with the changes here I can apply them in the
> Raspberry Pi Linux distribution, and then we can look to upstream them
> too.

I would suggest doing this the other way around.

The V4L2 patch should already be posted to the V4L2 mailing list, to get
early review comments.

"Upstream first" is always better ;-)

--
Kieran


> Thanks in advance
> 
> David
> 
> David Plowman (4):
>   ipa: raspberrypi: Make CamHelper exposure methods virtual
>   ipa: raspberrypi: Add CamHelper::ColourGainCode method
>   include: linux: Add V4L2_CID_NOTIFY_GAIN_XXX controls
>   ipa: raspberrypi: Update sensor's V4L2_CID_NOTIFY_GAIN_RED/BLUE
>     controls when present
> 
>  include/libcamera/ipa/raspberrypi.mojom        |  1 +
>  include/linux/v4l2-controls.h                  |  4 ++++
>  src/ipa/raspberrypi/cam_helper.cpp             | 18 ++++++++++++++++++
>  src/ipa/raspberrypi/cam_helper.hpp             |  8 +++++---
>  src/ipa/raspberrypi/raspberrypi.cpp            | 13 +++++++++++++
>  .../pipeline/raspberrypi/raspberrypi.cpp       | 10 ++++++++++
>  6 files changed, 51 insertions(+), 3 deletions(-)
> 

-- 
Regards
--
Kieran