Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754280AbdLHQHf (ORCPT ); Fri, 8 Dec 2017 11:07:35 -0500 Received: from bombadil.infradead.org ([65.50.211.133]:58766 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753656AbdLHQHd (ORCPT ); Fri, 8 Dec 2017 11:07:33 -0500 Date: Fri, 8 Dec 2017 14:07:25 -0200 From: Mauro Carvalho Chehab To: Nicolas Dufresne Cc: Smitha T Murthy , linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, kyungmin.park@samsung.com, kamil@wypas.org, jtp.park@samsung.com, a.hajda@samsung.com, pankaj.dubey@samsung.com, krzk@kernel.org, m.szyprowski@samsung.com, s.nawrocki@samsung.com Subject: Re: [Patch v6 05/12] [media] videodev2.h: Add v4l2 definition for HEVC Message-ID: <20171208140717.68dd1549@vento.lan> In-Reply-To: <1512748044.24635.1.camel@ndufresne.ca> References: <1512724105-1778-1-git-send-email-smitha.t@samsung.com> <1512724105-1778-6-git-send-email-smitha.t@samsung.com> <1512748044.24635.1.camel@ndufresne.ca> X-Mailer: Claws Mail 3.15.1-dirty (GTK+ 2.24.31; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id vB8G7eA7023028 Content-Length: 2085 Lines: 49 Em Fri, 08 Dec 2017 10:47:24 -0500 Nicolas Dufresne escreveu: > Le vendredi 08 décembre 2017 à 14:38 +0530, Smitha T Murthy a écrit : > > Add V4L2 definition for HEVC compressed format > > > > Signed-off-by: Smitha T Murthy > > Reviewed-by: Andrzej Hajda > > Reviewed-by: Stanimir Varbanov > > Acked-by: Hans Verkuil > > --- > > include/uapi/linux/videodev2.h | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h > > index 185d6a0..bd9b5d5 100644 > > --- a/include/uapi/linux/videodev2.h > > +++ b/include/uapi/linux/videodev2.h > > @@ -634,6 +634,7 @@ struct v4l2_pix_format { > > #define V4L2_PIX_FMT_VC1_ANNEX_L v4l2_fourcc('V', 'C', '1', 'L') /* SMPTE 421M Annex L compliant stream */ > > #define V4L2_PIX_FMT_VP8 v4l2_fourcc('V', 'P', '8', '0') /* VP8 */ > > #define V4L2_PIX_FMT_VP9 v4l2_fourcc('V', 'P', '9', '0') /* VP9 */ > > +#define V4L2_PIX_FMT_HEVC v4l2_fourcc('H', 'E', 'V', 'C') /* HEVC aka H.265 */ > > Wouldn't it be more consistent to call it V4L2_PIX_FMT_H265 as we have > used H264 for the previous generation, or is there a formal rationale ? It would, but what I'm afraid on using specs name here, due to what happened with MPEG-4 specs. Originally, it was referred to one codec (ASP). Then, part 10 came with a different compression codec (AVC). So, now, when referring to MPEG-4, one need to explicitly mention if the code is AVC or not. The ITU-T didn't make the same mistake (yet?), but nobody can predict what will happen in the future. So, now that an spec can be modified to include additional parts with different codecs, it sounds less risky to use the codec name instead of the spec number, as this shouldn't change :-) > Also, this is byte-stream right ? With start codes ? > > > > > /* Vendor-specific formats */ > > #define V4L2_PIX_FMT_CPIA1 v4l2_fourcc('C', 'P', 'I', 'A') /* cpia1 YUV */ Thanks, Mauro