Support for 12 and 16bit bayer formats

[Josh Doe]

On Thu, Oct 26, 2017 at 2:39 AM, Edgar Thier
<edgar.thier at theimagingsource.com> wrote:
> Hi,
>
> I was wondering how gstreamer-1.0 support for 12 and 16 bit bayer formats could look like.
> I am maintaining a custom source for industrial cameras that offer these formats and would like to
> make them available to users.
>
> The best information concerning the current state I could find is this bug:
> https://bugzilla.gnome.org/show_bug.cgi?id=693666
>
> I would like to implement the format descriptions in a way that can be handled by other elements
> like bayer2rgb, once they add support for non 8-bit bayer.
>
> Are there any plans to add support for these formats in the near future?
> If not, are there guidelines/best practices on how to add custom formats?

Good timing! I just finished writing a plugin for ON Semi/Aptina
Imaging cameras, which I'll be adding to gst-plugins-vision [1], and
that includes support for 10 to 16-bit Bayer. In turn I was expanding
the videolevels element (also in gst-plugins-vision) to support
stretching (think MATLAB imadjust) 16-bit Bayer to 8-bit Bayer, for
conversion with bayer2rgb. Of course there's also bayer2rgb2 (the
patch for which I failed to follow up on can be found here [2]), that
directly converts 16-bit Bayer to ARGB64.

We shouldn't forget Aravis, which supports GigE Vision and USB3 Vision
on Linux, which currently doesn't support 16-bit Bayer but could
easily be extended to do so. It even mentions bug #693666 as a blocker
[3].

This might be the motivation I need to clean up the patches. Please
look at the referenced bugs and give your input.

[1]: https://github.com/joshdoe/gst-plugins-vision
[2]: https://bugzilla.gnome.org/show_bug.cgi?id=607342
[3]: https://github.com/AravisProject/aravis/blob/016a3c9fbebf8adab8043c1f4ea300db4f64d330/src/arvmisc.c#L666