From mboxrd@z Thu Jan 1 00:00:00 1970 From: tiffany lin Subject: Re: [PATCH v3 3/9] DocBook/v4l: Add compressed video formats used on MT8173 codec driver Date: Wed, 13 Jul 2016 10:00:09 +0800 Message-ID: <1468375209.2462.20.camel@mtksdaap41> References: <1464611363-14936-1-git-send-email-tiffany.lin@mediatek.com> <1464611363-14936-2-git-send-email-tiffany.lin@mediatek.com> <1464611363-14936-3-git-send-email-tiffany.lin@mediatek.com> <1464611363-14936-4-git-send-email-tiffany.lin@mediatek.com> <5a793171-24a7-4e9e-8bfd-f668c789f8e0@xs4all.nl> <1468205771.3725.8.camel@mtksdaap41> <1468350511.8843.16.camel@gmail.com> <1468350842.8843.18.camel@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1468350842.8843.18.camel@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: nicolas@ndufresne.ca Cc: Wu-Cheng Li =?UTF-8?Q?=28=E6=9D=8E=E5=8B=99=E8=AA=A0=29?= , Hans Verkuil , Hans Verkuil , Daniel Thompson , Rob Herring , Mauro Carvalho Chehab , Matthias Brugger , Daniel Kurtz , Pawel Osciak , Eddie Huang , Yingjoe Chen , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, linux-mediatek@lists.infradead.org, Lin PoChun List-Id: devicetree@vger.kernel.org Hi Nicolas, On Tue, 2016-07-12 at 15:14 -0400, Nicolas Dufresne wrote: > Le mardi 12 juillet 2016 =C3=A0 15:08 -0400, Nicolas Dufresne a =C3=A9= crit : > > Le mardi 12 juillet 2016 =C3=A0 16:16 +0800, Wu-Cheng Li (=E6=9D=8E= =E5=8B=99=E8=AA=A0) a =C3=A9crit : > > > Decoder hardware produces MT21 (compressed). Image processor can > > > convert it to a format that can be input of display driver. > > > Tiffany. > > > When do you plan to upstream image processor (mtk-mdp)? > > > >=20 > > > > It can be as input format for encoder, MDP and display drivers = in > > > our > > > > platform. > > > I remember display driver can only accept uncompressed MT21. Righ= t? > > > Basically V4L2_PIX_FMT_MT21 is compressed and is like an opaque > > > format. It's not usable until it's decompressed and converted by > > > image > > > processor. > >=20 > > Previously it was described as MediaTek block mode, and now as a > > MediaTek compressed format. It makes me think you have no idea what > > this pixel format really is. Is that right ? > >=20 > > The main reason why I keep asking, is that we often find similariti= es > > between what vendor like to call their proprietary formats. Doing t= he > > proper research helps not creating a mess like in Android where you > > have a lot of formats that all point to the same format. I believe > > there was the same concern when Samsung wanted to introduce their Z= - > > flip-Z NV12 tile format. In the end they simply provided sufficient > > documentation so we could document it and implement software > > converters > > for test and validation purpose. >=20 > Here's the kind of information we want in the documentation. >=20 > https://chromium.googlesource.com/chromium/src/media/+/master/base/vi= de > o_types.h#40 >=20 > // MediaTek proprietary format. MT21 is similar to NV21 except the = memory > // layout and pixel layout (swizzles). 12bpp with Y plane followed = by a 2x2 > // interleaved VU plane. Each image contains two buffers -- Y plane= and VU > // plane. Two planes can be non-contiguous in memory. The starting = addresses > // of Y plane and VU plane are 4KB alignment. > // Suppose image dimension is (width, height). For both Y plane and= VU plane: > // Row pitch =3D ((width+15)/16) * 16. > // Plane size =3D Row pitch * (((height+31)/32)*32) >=20 > Now obviously this is incomplete, as the swizzling need to be documen= ted of course. >=20 Because it's finally a compressed format from our codec hw, we cannot describe its swizzling. best regards, Tiffany > >=20 > > regards, > > Nicolas