Re: [PATCH 2/9] v4l: Add definitions for missing 16-bit RGB4444 formats

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Jacopo,

On Thu, Apr 04, 2019 at 06:00:49PM +0200, Jacopo Mondi wrote:
> On Thu, Mar 28, 2019 at 09:07:16AM +0200, Laurent Pinchart wrote:
> > The V4L2 API is missing the 16-bit RGB4444 formats for the RGBA, RGBX,
> > ABGR, XBGR, BGRA and BGRX component orders. Add them, using the same
> > 4CCs as DRM.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> 
> I checked the documentation and it seems right, I cannot relate the
> name to the ordering but I guess this is intended.

The 16-bit RGB V4L2 4CCs are named based on a little endian byte
ordering. If you look at V4L2_PIX_FMT_RGBA444 for instance, we have, in
memory

	bbbbaaaa rrrrgggg

If you read that as a 16-bit integer in little endian order, you get

	rrrrggggbbbbaaaa

hence the name RGBA444.

> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
> 
> > ---
> >  .../media/uapi/v4l/pixfmt-packed-rgb.rst      | 138 ++++++++++++++++++
> >  include/uapi/linux/videodev2.h                |   6 +
> >  2 files changed, 144 insertions(+)
> >
> > diff --git a/Documentation/media/uapi/v4l/pixfmt-packed-rgb.rst b/Documentation/media/uapi/v4l/pixfmt-packed-rgb.rst
> > index 055f9c89e787..b475cbba492f 100644
> > --- a/Documentation/media/uapi/v4l/pixfmt-packed-rgb.rst
> > +++ b/Documentation/media/uapi/v4l/pixfmt-packed-rgb.rst
> > @@ -139,6 +139,144 @@ next to each other in memory.
> >        - r\ :sub:`1`
> >        - r\ :sub:`0`
> >        -
> > +    * .. _V4L2-PIX-FMT-RGBA444:
> > +
> > +      - ``V4L2_PIX_FMT_RGBA444``
> > +      - 'RA12'
> > +
> > +      - b\ :sub:`3`
> > +      - b\ :sub:`2`
> > +      - b\ :sub:`1`
> > +      - b\ :sub:`0`
> > +      - a\ :sub:`3`
> > +      - a\ :sub:`2`
> > +      - a\ :sub:`1`
> > +      - a\ :sub:`0`
> > +
> > +      - r\ :sub:`3`
> > +      - r\ :sub:`2`
> > +      - r\ :sub:`1`
> > +      - r\ :sub:`0`
> > +      - g\ :sub:`3`
> > +      - g\ :sub:`2`
> > +      - g\ :sub:`1`
> > +      - g\ :sub:`0`
> > +      -
> > +    * .. _V4L2-PIX-FMT-RGBX444:
> > +
> > +      - ``V4L2_PIX_FMT_RGBX444``
> > +      - 'RX12'
> > +
> > +      - b\ :sub:`3`
> > +      - b\ :sub:`2`
> > +      - b\ :sub:`1`
> > +      - b\ :sub:`0`
> > +      -
> > +      -
> > +      -
> > +      -
> > +
> > +      - r\ :sub:`3`
> > +      - r\ :sub:`2`
> > +      - r\ :sub:`1`
> > +      - r\ :sub:`0`
> > +      - g\ :sub:`3`
> > +      - g\ :sub:`2`
> > +      - g\ :sub:`1`
> > +      - g\ :sub:`0`
> > +      -
> > +    * .. _V4L2-PIX-FMT-ABGR444:
> > +
> > +      - ``V4L2_PIX_FMT_ABGR444``
> > +      - 'AB12'
> > +
> > +      - g\ :sub:`3`
> > +      - g\ :sub:`2`
> > +      - g\ :sub:`1`
> > +      - g\ :sub:`0`
> > +      - r\ :sub:`3`
> > +      - r\ :sub:`2`
> > +      - r\ :sub:`1`
> > +      - r\ :sub:`0`
> > +
> > +      - a\ :sub:`3`
> > +      - a\ :sub:`2`
> > +      - a\ :sub:`1`
> > +      - a\ :sub:`0`
> > +      - b\ :sub:`3`
> > +      - b\ :sub:`2`
> > +      - b\ :sub:`1`
> > +      - b\ :sub:`0`
> > +      -
> > +    * .. _V4L2-PIX-FMT-XBGR444:
> > +
> > +      - ``V4L2_PIX_FMT_XBGR444``
> > +      - 'XB12'
> > +
> > +      - g\ :sub:`3`
> > +      - g\ :sub:`2`
> > +      - g\ :sub:`1`
> > +      - g\ :sub:`0`
> > +      - r\ :sub:`3`
> > +      - r\ :sub:`2`
> > +      - r\ :sub:`1`
> > +      - r\ :sub:`0`
> > +
> > +      -
> > +      -
> > +      -
> > +      -
> > +      - b\ :sub:`3`
> > +      - b\ :sub:`2`
> > +      - b\ :sub:`1`
> > +      - b\ :sub:`0`
> > +      -
> > +    * .. _V4L2-PIX-FMT-BGRA444:
> > +
> > +      - ``V4L2_PIX_FMT_BGRA444``
> > +      - 'BA12'
> > +
> > +      - r\ :sub:`3`
> > +      - r\ :sub:`2`
> > +      - r\ :sub:`1`
> > +      - r\ :sub:`0`
> > +      - a\ :sub:`3`
> > +      - a\ :sub:`2`
> > +      - a\ :sub:`1`
> > +      - a\ :sub:`0`
> > +
> > +      - b\ :sub:`3`
> > +      - b\ :sub:`2`
> > +      - b\ :sub:`1`
> > +      - b\ :sub:`0`
> > +      - g\ :sub:`3`
> > +      - g\ :sub:`2`
> > +      - g\ :sub:`1`
> > +      - g\ :sub:`0`
> > +      -
> > +    * .. _V4L2-PIX-FMT-BGRX444:
> > +
> > +      - ``V4L2_PIX_FMT_BGRX444``
> > +      - 'BX12'
> > +
> > +      - r\ :sub:`3`
> > +      - r\ :sub:`2`
> > +      - r\ :sub:`1`
> > +      - r\ :sub:`0`
> > +      -
> > +      -
> > +      -
> > +      -
> > +
> > +      - b\ :sub:`3`
> > +      - b\ :sub:`2`
> > +      - b\ :sub:`1`
> > +      - b\ :sub:`0`
> > +      - g\ :sub:`3`
> > +      - g\ :sub:`2`
> > +      - g\ :sub:`1`
> > +      - g\ :sub:`0`
> > +      -
> >      * .. _V4L2-PIX-FMT-ARGB555:
> >
> >        - ``V4L2_PIX_FMT_ARGB555``
> > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > index 4e5222726719..df9fa78a6ab7 100644
> > --- a/include/uapi/linux/videodev2.h
> > +++ b/include/uapi/linux/videodev2.h
> > @@ -514,6 +514,12 @@ struct v4l2_pix_format {
> >  #define V4L2_PIX_FMT_RGB444  v4l2_fourcc('R', '4', '4', '4') /* 16  xxxxrrrr ggggbbbb */
> >  #define V4L2_PIX_FMT_ARGB444 v4l2_fourcc('A', 'R', '1', '2') /* 16  aaaarrrr ggggbbbb */
> >  #define V4L2_PIX_FMT_XRGB444 v4l2_fourcc('X', 'R', '1', '2') /* 16  xxxxrrrr ggggbbbb */
> > +#define V4L2_PIX_FMT_RGBA444 v4l2_fourcc('R', 'A', '1', '2') /* 16  rrrrgggg bbbbaaaa */
> > +#define V4L2_PIX_FMT_RGBX444 v4l2_fourcc('R', 'X', '1', '2') /* 16  rrrrgggg bbbbxxxx */
> > +#define V4L2_PIX_FMT_ABGR444 v4l2_fourcc('A', 'B', '1', '2') /* 16  aaaabbbb ggggrrrr */
> > +#define V4L2_PIX_FMT_XBGR444 v4l2_fourcc('X', 'B', '1', '2') /* 16  xxxxbbbb ggggrrrr */
> > +#define V4L2_PIX_FMT_BGRA444 v4l2_fourcc('B', 'A', '1', '2') /* 16  bbbbgggg rrrraaaa */
> > +#define V4L2_PIX_FMT_BGRX444 v4l2_fourcc('B', 'X', '1', '2') /* 16  bbbbgggg rrrrxxxx */
> >  #define V4L2_PIX_FMT_RGB555  v4l2_fourcc('R', 'G', 'B', 'O') /* 16  RGB-5-5-5     */
> >  #define V4L2_PIX_FMT_ARGB555 v4l2_fourcc('A', 'R', '1', '5') /* 16  ARGB-1-5-5-5  */
> >  #define V4L2_PIX_FMT_XRGB555 v4l2_fourcc('X', 'R', '1', '5') /* 16  XRGB-1-5-5-5  */
> > --
> > Regards,
> >
> > Laurent Pinchart
> >



-- 
Regards,

Laurent Pinchart