12-bit bayer support in v4l2src ?

[Josh Doe]

On Fri, Jun 22, 2018 at 4:05 AM Philippe De Muyter <phdm at macq.eu> wrote:
> I try to use a 12-bit bayer sensor in a gstreamer pipe-line, but even
> the simplest pipeline
>
> [...]

> Has v4l2src evolved in newer versions to support RG12 ?

First caps must be settled on, see here as Edgar pointed out:
https://bugzilla.gnome.org/show_bug.cgi?id=693666

Then v4l2src must support these caps and associated data layout. No
associated ticket for this yet.

Then bayer2rgb *could* be extended, which is covered in this bug:
https://bugzilla.gnome.org/show_bug.cgi?id=607342

However, if you don't need ARGB64, you really just want to convert
from 12-bit Bayer to 8-bit, and can use the existing bayer2rgb, so you
only need to do the first two things listed above. To convert from 12-
to 8-bit I capssetter to/from GRAY16 and use my videolevels element
which uses the image's histogram to retain the most image content:
https://github.com/joshdoe/gst-plugins-vision/blob/master/gst/videoadjust/gstvideolevels.c

It's been on my TODO list a long time to work on this high bit depth
Bayer business, but it keeps on being shifted down the road.