Hi Laurent,
thanks for explaining.
On Tue, Apr 02, 2019 at 03:12:00PM +0300, Laurent Pinchart wrote:
> Hi Jacopo,
>
> On Thu, Mar 28, 2019 at 02:15:43PM +0100, Jacopo Mondi wrote:
> > On Thu, Mar 28, 2019 at 09:07:15AM +0200, Laurent Pinchart wrote:
> > > The V4L2 API is missing the 32-bit RGB formats for the ABGR, XBGR, RGBA
> > > and RGBX component orders. Add them, using the same 4CCs as DRM.
> > >
> > > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> > > ---
> > > .../media/uapi/v4l/pixfmt-packed-rgb.rst | 160 ++++++++++++++++++
> > > include/uapi/linux/videodev2.h | 4 +
> > > 2 files changed, 164 insertions(+)
> > >
> > > diff --git a/Documentation/media/uapi/v4l/pixfmt-packed-rgb.rst b/Documentation/media/uapi/v4l/pixfmt-packed-rgb.rst
> > > index 6b3781c04dd5..055f9c89e787 100644
> > > --- a/Documentation/media/uapi/v4l/pixfmt-packed-rgb.rst
> > > +++ b/Documentation/media/uapi/v4l/pixfmt-packed-rgb.rst
> > > @@ -453,6 +453,166 @@ next to each other in memory.
> > > - r\ :sub:`1`
> > > - r\ :sub:`0`
> > >
> > > + -
> > > + -
> > > + -
> > > + -
> > > + -
> > > + -
> > > + -
> > > + -
> > > + * .. _V4L2-PIX-FMT-BGRA32:
> > > +
> > > + - ``V4L2_PIX_FMT_BGRA32``
> > > + - 'RA24'
> > > +
> > > + - a\ :sub:`7`
> > > + - a\ :sub:`6`
> > > + - a\ :sub:`5`
> > > + - a\ :sub:`4`
> > > + - a\ :sub:`3`
> > > + - a\ :sub:`2`
> > > + - a\ :sub:`1`
> > > + - a\ :sub:`0`
> > > +
> > > + - b\ :sub:`7`
> > > + - b\ :sub:`6`
> > > + - b\ :sub:`5`
> > > + - b\ :sub:`4`
> > > + - b\ :sub:`3`
> > > + - b\ :sub:`2`
> > > + - b\ :sub:`1`
> > > + - b\ :sub:`0`
> > > +
> > > + - g\ :sub:`7`
> > > + - g\ :sub:`6`
> > > + - g\ :sub:`5`
> > > + - g\ :sub:`4`
> > > + - g\ :sub:`3`
> > > + - g\ :sub:`2`
> > > + - g\ :sub:`1`
> > > + - g\ :sub:`0`
> > > +
> > > + - r\ :sub:`7`
> > > + - r\ :sub:`6`
> > > + - r\ :sub:`5`
> > > + - r\ :sub:`4`
> > > + - r\ :sub:`3`
> > > + - r\ :sub:`2`
> > > + - r\ :sub:`1`
> > > + - r\ :sub:`0`
> > > + * .. _V4L2-PIX-FMT-BGRX32:
> > > +
> > > + - ``V4L2_PIX_FMT_BGRX32``
> > > + - 'RX24'
> > > +
> > > + -
> > > + -
> > > + -
> > > + -
> > > + -
> > > + -
> > > + -
> > > + -
> > > +
> > > + - b\ :sub:`7`
> > > + - b\ :sub:`6`
> > > + - b\ :sub:`5`
> > > + - b\ :sub:`4`
> > > + - b\ :sub:`3`
> > > + - b\ :sub:`2`
> > > + - b\ :sub:`1`
> > > + - b\ :sub:`0`
> > > +
> > > + - g\ :sub:`7`
> > > + - g\ :sub:`6`
> > > + - g\ :sub:`5`
> > > + - g\ :sub:`4`
> > > + - g\ :sub:`3`
> > > + - g\ :sub:`2`
> > > + - g\ :sub:`1`
> > > + - g\ :sub:`0`
> > > +
> > > + - r\ :sub:`7`
> > > + - r\ :sub:`6`
> > > + - r\ :sub:`5`
> > > + - r\ :sub:`4`
> > > + - r\ :sub:`3`
> > > + - r\ :sub:`2`
> > > + - r\ :sub:`1`
> > > + - r\ :sub:`0`
> > > + * .. _V4L2-PIX-FMT-RGBA32:
> > > +
> > > + - ``V4L2_PIX_FMT_RGBA32``
> > > + - 'AB24'
> > > +
> > > + - r\ :sub:`7`
> > > + - r\ :sub:`6`
> > > + - r\ :sub:`5`
> > > + - r\ :sub:`4`
> > > + - r\ :sub:`3`
> > > + - r\ :sub:`2`
> > > + - r\ :sub:`1`
> > > + - r\ :sub:`0`
> > > +
> > > + - g\ :sub:`7`
> > > + - g\ :sub:`6`
> > > + - g\ :sub:`5`
> > > + - g\ :sub:`4`
> > > + - g\ :sub:`3`
> > > + - g\ :sub:`2`
> > > + - g\ :sub:`1`
> > > + - g\ :sub:`0`
> > > +
> > > + - b\ :sub:`7`
> > > + - b\ :sub:`6`
> > > + - b\ :sub:`5`
> > > + - b\ :sub:`4`
> > > + - b\ :sub:`3`
> > > + - b\ :sub:`2`
> > > + - b\ :sub:`1`
> > > + - b\ :sub:`0`
> > > +
> > > + - a\ :sub:`7`
> > > + - a\ :sub:`6`
> > > + - a\ :sub:`5`
> > > + - a\ :sub:`4`
> > > + - a\ :sub:`3`
> > > + - a\ :sub:`2`
> > > + - a\ :sub:`1`
> > > + - a\ :sub:`0`
> > > + * .. _V4L2-PIX-FMT-RGBX32:
> > > +
> > > + - ``V4L2_PIX_FMT_RGBX32``
> > > + - 'XB24'
> > > +
> > > + - r\ :sub:`7`
> > > + - r\ :sub:`6`
> > > + - r\ :sub:`5`
> > > + - r\ :sub:`4`
> > > + - r\ :sub:`3`
> > > + - r\ :sub:`2`
> > > + - r\ :sub:`1`
> > > + - r\ :sub:`0`
> > > +
> > > + - g\ :sub:`7`
> > > + - g\ :sub:`6`
> > > + - g\ :sub:`5`
> > > + - g\ :sub:`4`
> > > + - g\ :sub:`3`
> > > + - g\ :sub:`2`
> > > + - g\ :sub:`1`
> > > + - g\ :sub:`0`
> > > +
> > > + - b\ :sub:`7`
> > > + - b\ :sub:`6`
> > > + - b\ :sub:`5`
> > > + - b\ :sub:`4`
> > > + - b\ :sub:`3`
> > > + - b\ :sub:`2`
> > > + - b\ :sub:`1`
> > > + - b\ :sub:`0`
> > > +
> >
> > I'm trying to compare these with the existing 32-bit RGB formats in
> > pixfmt-packed-rgb.rst and I can't get how the orderig of components is
> > defined.
>
> Pixel formats are all a big mess :-)
>
> > Ie your definitions here:
> >
> > bytes: B0 B1 B2 B3
> > BGRA32 A B G R
> > BGRX32 x B G R
> > RGBA32 R G B A
> > RGBX32 R G B x
> >
> > In the existing documentation:
> > ABGR32 B G R A
> > XBGR32 B G R x
> > ARGB32 A R G B
> > XRGB32 x R G B
>
> > So you're adding two BGR/RGB variations with 'X' or 'A' moved from the
> > first (for RGB) or last (for BGR) bytes to the last (for RGB) or first
> > (for BGR) bytes.
> >
> > I cannot see a clear pattern (it seems RGB is ordered as you read the
> > components, while BGR is inverted?) so I assume the definition of the
> > component ordering scheme comes from a standard, does it? A reference
> > would help checking for errors :)
>
> The existing formats are pretty inconsistent. I suppose ARGB and XRGB
> were added first, with the format names corresponding to the pixel order
> in memory. Then a need to support BGRA and BGRX arose, and the format
> names were set to ABGR32 and XBGR32 instead of BGRA32 and BGRX32.
> Unfortuantely we can't fix this as it's an ABI, so I had to follow the
> same scheme for the new formats. RGBA and RGBX are fine as the RGBA31
> and RGBX32 names were free, but for ABGR and XBGR I had to use the
> BGRA32 and BGRX32 names.
>
The generated documentation seems good to me.
Reviewed-by: Jacopo Mondi <jacopo@xxxxxxxxxx>
Thanks
j
> > > -
> > > -
> > > -
> > > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > > index 1db220da3bcc..4e5222726719 100644
> > > --- a/include/uapi/linux/videodev2.h
> > > +++ b/include/uapi/linux/videodev2.h
> > > @@ -528,7 +528,11 @@ struct v4l2_pix_format {
> > > #define V4L2_PIX_FMT_BGR32 v4l2_fourcc('B', 'G', 'R', '4') /* 32 BGR-8-8-8-8 */
> > > #define V4L2_PIX_FMT_ABGR32 v4l2_fourcc('A', 'R', '2', '4') /* 32 BGRA-8-8-8-8 */
> > > #define V4L2_PIX_FMT_XBGR32 v4l2_fourcc('X', 'R', '2', '4') /* 32 BGRX-8-8-8-8 */
> > > +#define V4L2_PIX_FMT_BGRA32 v4l2_fourcc('R', 'A', '2', '4') /* 32 ABGR-8-8-8-8 */
> > > +#define V4L2_PIX_FMT_BGRX32 v4l2_fourcc('R', 'X', '2', '4') /* 32 XBGR-8-8-8-8 */
> > > #define V4L2_PIX_FMT_RGB32 v4l2_fourcc('R', 'G', 'B', '4') /* 32 RGB-8-8-8-8 */
> > > +#define V4L2_PIX_FMT_RGBA32 v4l2_fourcc('A', 'B', '2', '4') /* 32 RGBA-8-8-8-8 */
> > > +#define V4L2_PIX_FMT_RGBX32 v4l2_fourcc('X', 'B', '2', '4') /* 32 RGBX-8-8-8-8 */
> > > #define V4L2_PIX_FMT_ARGB32 v4l2_fourcc('B', 'A', '2', '4') /* 32 ARGB-8-8-8-8 */
> > > #define V4L2_PIX_FMT_XRGB32 v4l2_fourcc('B', 'X', '2', '4') /* 32 XRGB-8-8-8-8 */
> > >
>
> --
> Regards,
>
> Laurent Pinchart
Attachment:
signature.asc
Description: PGP signature
