From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from ec2-52-27-115-49.us-west-2.compute.amazonaws.com ([52.27.115.49]:40817 "EHLO s-opensource.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964810AbcIFSVV (ORCPT ); Tue, 6 Sep 2016 14:21:21 -0400 Date: Tue, 6 Sep 2016 15:21:15 -0300 From: Mauro Carvalho Chehab To: Laurent Pinchart Cc: Laurent Pinchart , linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Sakari Ailus , Hans Verkuil , Guennadi Liakhovetski Subject: Re: [PATCH v2 2/4] v4l: Define a pixel format for the R-Car VSP1 1-D histogram engine Message-ID: <20160906152115.25241928@vento.lan> In-Reply-To: <2924098.oMaQNCPtyr@avalon> References: <1471436430-26245-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> <1471436430-26245-3-git-send-email-laurent.pinchart+renesas@ideasonboard.com> <20160906140651.214e6f01@vento.lan> <2924098.oMaQNCPtyr@avalon> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Em Tue, 06 Sep 2016 21:11:10 +0300 Laurent Pinchart escreveu: > Hi Mauro, > > On Tuesday 06 Sep 2016 14:06:51 Mauro Carvalho Chehab wrote: > > Em Wed, 17 Aug 2016 15:20:28 +0300 Laurent Pinchart escreveu: > > > The format is used on the R-Car VSP1 video queues that carry > > > 1-D histogram statistics data. > > > > > > Signed-off-by: Laurent Pinchart > > > > > > Acked-by: Sakari Ailus > > > --- > > > Changes since v1: > > > > > > - Rebased on top of the DocBook to reST conversion > > > > > > Documentation/media/uapi/v4l/meta-formats.rst | 15 ++ > > > .../media/uapi/v4l/pixfmt-meta-vsp1-hgo.rst | 170 ++++++++++++++++ > > > Documentation/media/uapi/v4l/pixfmt.rst | 1 + > > > drivers/media/v4l2-core/v4l2-ioctl.c | 1 + > > > include/uapi/linux/videodev2.h | 3 + > > > 5 files changed, 190 insertions(+) > > > create mode 100644 Documentation/media/uapi/v4l/meta-formats.rst > > > create mode 100644 Documentation/media/uapi/v4l/pixfmt-meta-vsp1-hgo.rst > > > > > > diff --git a/Documentation/media/uapi/v4l/meta-formats.rst > > > b/Documentation/media/uapi/v4l/meta-formats.rst new file mode 100644 > > > index 000000000000..05ab91e12f10 > > > --- /dev/null > > > +++ b/Documentation/media/uapi/v4l/meta-formats.rst > > > @@ -0,0 +1,15 @@ > > > +.. -*- coding: utf-8; mode: rst -*- > > > + > > > +.. _meta-formats: > > > + > > > +**************** > > > +Metadata Formats > > > +**************** > > > + > > > +These formats are used for the :ref:`metadata` interface only. > > > + > > > + > > > +.. toctree:: > > > + :maxdepth: 1 > > > + > > > + pixfmt-meta-vsp1-hgo > > > diff --git a/Documentation/media/uapi/v4l/pixfmt-meta-vsp1-hgo.rst > > > b/Documentation/media/uapi/v4l/pixfmt-meta-vsp1-hgo.rst new file mode > > > 100644 > > > index 000000000000..e935e4525b10 > > > --- /dev/null > > > +++ b/Documentation/media/uapi/v4l/pixfmt-meta-vsp1-hgo.rst > > > @@ -0,0 +1,170 @@ > > > +.. -*- coding: utf-8; mode: rst -*- > > > + > > > +.. _v4l2-meta-fmt-vsp1-hgo: > > > + > > > +******************************* > > > +V4L2_META_FMT_VSP1_HGO ('VSPH') > > > +******************************* > > > + > > > +*man V4L2_META_FMT_VSP1_HGO(2)* > > > > Just remove it. This is some trash that came from the conversions. > > I have a set of patches removing it on the existing man pages. > > Sure, I will do. Thanks! > > > + > > > +Renesas R-Car VSP1 1-D Histogram Data > > > + > > > + > > > +Description > > > +=========== > > > + > > > +This format describes histogram data generated by the Renesas R-Car VSP1 > > > 1-D +Histogram (HGO) engine. > > > + > > > +The VSP1 HGO is a histogram computation engine that can operate on RGB, > > > YCrCb +or HSV data. It operates on a possibly cropped and subsampled > > > input image and +computes the minimum, maximum and sum of all pixels as > > > well as per-channel +histograms. > > > + > > > +The HGO can compute histograms independently per channel, on the maximum > > > of the +three channels (RGB data only) or on the Y channel only (YCbCr > > > only). It can +additionally output the histogram with 64 or 256 bins, > > > resulting in four +possible modes of operation. > > > + > > > +- In *64 bins normal mode*, the HGO operates on the three channels > > > independently + to compute three 64-bins histograms. RGB, YCbCr and HSV > > > image formats are + supported. > > > +- In *64 bins maximum mode*, the HGO operates on the maximum of the (R, > > > G, B) + channels to compute a single 64-bins histogram. Only the RGB > > > image format is + supported. > > > +- In *256 bins normal mode*, the HGO operates on the Y channel to compute > > > a + single 256-bins histogram. Only the YCbCr image format is supported. > > > +- In *256 bins maximum mode*, the HGO operates on the maximum of the (R, > > > G, B) + channels to compute a single 256-bins histogram. Only the RGB > > > image format is + supported. > > > > As they all share the same FOURCC format, according with the documentation, > > how the user is supposed to switch between those modes? Or is it depend on > > the video format? In any case, please add some explanation, and cross-refs > > if needed. > > The modes are selected using controls, they don't depend on the video format. > Do you think it would make sense to cross-reference between formats and > controls ? It probably makes a way more sense to use enum_fmt/s_fmt/g_fmt ioctls and add one different fourcc per format. Using a control instead of *fmt to select the format seems really weird, as it is not what it is expected for the fourcc formats. Thanks, Mauro