RFC: V4L2_PIX_FMT_NV16: should it allow padding after each plane?

RFC: V4L2_PIX_FMT_NV16: should it allow padding after each plane?

[Hans Verkuil]

The NV16 documentation allows for padding after each line:

https://hverkuil.home.xs4all.nl/spec/uapi/v4l/pixfmt-nv16.html

But I have one case where there is also padding after each plane.

Can we fold that into the existing NV16 format? I.e., in that case
the size of each plane is sizeimage / 2.

Or do I have to make a new NV16PAD format that allows such padding?

I am in favor of extending the NV16 specification since I believe it
makes sense, but I want to know what others think.

Regards,

	Hans

Re: RFC: V4L2_PIX_FMT_NV16: should it allow padding after each plane?

[Sakari Ailus]

Hi Hans,

On Wed, Aug 31, 2016 at 10:43:03AM +0200, Hans Verkuil wrote:
> The NV16 documentation allows for padding after each line:
> 
> https://hverkuil.home.xs4all.nl/spec/uapi/v4l/pixfmt-nv16.html
> 
> But I have one case where there is also padding after each plane.
> 
> Can we fold that into the existing NV16 format? I.e., in that case
> the size of each plane is sizeimage / 2.

I can't see any harm in doing so. It likely catches most of the alignment
requirements.

That still probably doesn't catch all the possible cases but we always do
have the option of creating another format in that case.

> 
> Or do I have to make a new NV16PAD format that allows such padding?
> 
> I am in favor of extending the NV16 specification since I believe it
> makes sense, but I want to know what others think.

-- 
Regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi	XMPP: sailus@retiisi.org.uk