From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Hans Verkuil <hverkuil@xs4all.nl>
Cc: linux-media@vger.kernel.org
Subject: Re: [PATCH] v4l: Clarify RGB666 pixel format definition
Date: Tue, 22 Jul 2014 00:30:22 +0200 [thread overview]
Message-ID: <1479223.veAhoGoXLY@avalon> (raw)
In-Reply-To: <53CD8974.20109@xs4all.nl>
Hi Hans,
On Monday 21 July 2014 23:43:16 Hans Verkuil wrote:
> On 07/21/2014 10:39 PM, Laurent Pinchart wrote:
> > The RGB666 pixel format doesn't include an alpha channel. Document it as
> > such.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> >
> > .../DocBook/media/v4l/pixfmt-packed-rgb.xml | 20 +++++----------
> > 1 file changed, 6 insertions(+), 14 deletions(-)
> >
> > diff --git a/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml
> > b/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml index
> > 32feac9..c47692a 100644
> > --- a/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml
> > +++ b/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml
> > @@ -330,20 +330,12 @@ colorspace
> > <constant>V4L2_COLORSPACE_SRGB</constant>.</para>>
> > <entry></entry>
> > <entry>r<subscript>1</subscript></entry>
> > <entry>r<subscript>0</subscript></entry>
> > - <entry></entry>
> > - <entry></entry>
> > - <entry></entry>
> > - <entry></entry>
> > - <entry></entry>
> > - <entry></entry>
> > - <entry></entry>
> > - <entry></entry>
> > - <entry></entry>
> > - <entry></entry>
> > - <entry></entry>
> > - <entry></entry>
> > - <entry></entry>
> > - <entry></entry>
> > + <entry>-</entry>
> > + <entry>-</entry>
> > + <entry>-</entry>
> > + <entry>-</entry>
> > + <entry>-</entry>
> > + <entry>-</entry>
>
> Just to clarify: BGR666 is a three byte format, not a four byte format?
Well... :-)
Three drivers seem to support the BGR666 in mainline : sh_veu, s3c-camif and
exynos4-is. Further investigation shows that the sh_veu driver lists the
BGR666 format internally but doesn't expose it to userspace and doesn't
actually support it, so we're down to two drivers.
Looking at the S3C6410 datasheet, it's unclear how the hardware stores RGB666
pixels in memory. It could be either
Byte 0 Byte 1 Byte 2 Byte 3
-------- ------RR RRRRGGGG GGBBBBBB
or
GGBBBBBB RRRRGGGG ------RR --------
None of those correspond to the RGB666 format defined in the spec.
The Exynos4 FIMC isn't documented in the public datasheet, so I can't check
how the format is defined.
Furthermore, various Renesas video-related IP cores support many different
RGB666 variants, on either 32 or 24 bits per pixel, with and without alpha.
Beside a loud *sigh*, any comment ? :-)
> > </row>
> > <row id="V4L2-PIX-FMT-BGR24">
> > <entry><constant>V4L2_PIX_FMT_BGR24</constant></entry>
--
Regards,
Laurent Pinchart
next prev parent reply other threads:[~2014-07-21 22:30 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-21 20:39 [PATCH] v4l: Clarify RGB666 pixel format definition Laurent Pinchart
2014-07-21 21:43 ` Hans Verkuil
2014-07-21 22:30 ` Laurent Pinchart [this message]
2014-07-21 22:44 ` Hans Verkuil
2014-09-09 13:18 ` Laurent Pinchart
2014-09-09 14:45 ` Sylwester Nawrocki
2014-10-29 11:45 ` Laurent Pinchart
2015-11-09 22:21 ` Laurent Pinchart
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