From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from galahad.ideasonboard.com ([185.26.127.97]:50388 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S938965AbcIFSKt (ORCPT ); Tue, 6 Sep 2016 14:10:49 -0400 From: Laurent Pinchart To: Mauro Carvalho Chehab 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 Date: Tue, 06 Sep 2016 21:11:10 +0300 Message-ID: <2924098.oMaQNCPtyr@avalon> In-Reply-To: <20160906140651.214e6f01@vento.lan> 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> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: 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. > > + > > +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 ? [snip] -- Regards, Laurent Pinchart