Re: [RFC PATCH 2/3] media: v4l2: Extend pixel formats to unify single/multi-planar handling (and more)

[Boris Brezillon <boris.brezillon@collabora.com>]

On Tue, 19 Mar 2019 14:07:32 -0400
Nicolas Dufresne <nicolas@ndufresne.ca> wrote:

> Le mardi 19 mars 2019 à 15:52 +0100, Boris Brezillon a écrit :
> > +/**
> > + * struct v4l2_plane_ext_pix_format - additional, per-plane format definition
> > + * @modifier:          modifier applied to the format (used for tiled formats
> > + *                     and other kind of HW-specific formats, like compressed
> > + *                     formats)  
> 
> I have never seen HW that would allow per-plane modifiers on the DRM
> side, and I believe the newer API (enumeration) ignores this per-plane
> idea. Would be nice to investigate/verify this and avoid doing the same
> mistake.

I just check and you're right. I'll move the modifier field to
v4l2_ext_buffer.

> 
> > + * @sizeimage:         maximum size in bytes required for data, for which
> > + *                     this plane will be used
> > + * @bytesperline:      distance in bytes between the leftmost pixels in two
> > + *                     adjacent lines
> > + */
> > +struct v4l2_plane_ext_pix_format {
> > +       __u64 modifier;
> > +       __u32 sizeimage;
> > +       __u32 bytesperline;
> > +};