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Date: Fri, 2 Sep 2016 11:18:05 +0300
From: Sakari Ailus <sakari.ailus@iki.fi>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>,
        linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
        Hans Verkuil <hans.verkuil@cisco.com>,
        Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Subject: Re: [PATCH v2 1/4] v4l: Add metadata buffer type and format
Message-ID: <20160902081804.GY12130@valkosipuli.retiisi.org.uk>
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Hi Laurent,

On Fri, Sep 02, 2016 at 12:40:18AM +0300, Laurent Pinchart wrote:
...
> > >> +Data Format Negotiation
> > >> +=======================
> > >> +
> > >> +The metadata device uses the :ref:`format` ioctls to select the capture
> > >> format. +The metadata buffer content format is bound to that selected
> > >> format. In addition +to the basic :ref:`format` ioctls, the
> > >> 
> > >> :ref:`VIDIOC_ENUM_FMT` ioctl must be +supported as well.
> > >> 
> > >> +
> > >> +To use the :ref:`format` ioctls applications set the ``type`` of the
> > >> +:ref:`v4l2_format <v4l2-format>` structure to
> > >> ``V4L2_BUF_TYPE_META_CAPTURE`` +and use the :ref:`v4l2_meta_format
> > >> <v4l2-meta-format>` ``meta`` member of the +``fmt`` union as needed per
> > >> the desired operation. The :ref:`v4l2-meta-format` +structure contains
> > >> two fields, ``dataformat`` is set by applications to the V4L2
> > > 
> > > I might not specify the number of number of fields here. It has high
> > > chances of not getting updated when more fields are added. Up to you.
> > 
> > This has been copied from dev-sdr.rst. I can drop the last sentence
> > completely as the parameters are described in the table below. Hans, any
> > opinion ?
> 
> How about this ?
> 
> To use the :ref:`format` ioctls applications set the ``type`` of the

s/of/field of/

?

> :ref:`v4l2_format <v4l2-format>` structure to ``V4L2_BUF_TYPE_META_CAPTURE``
> and use the :ref:`v4l2_meta_format <v4l2-meta-format>` ``meta`` member of the
> ``fmt`` union as needed per the desired operation. Both drivers and 
> applications must set the remainder of the :ref:`v4l2_format <v4l2-format>` 
> structure to 0.

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