From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Dufresne Subject: Re: [PATCH v3 3/9] DocBook/v4l: Add compressed video formats used on MT8173 codec driver Date: Tue, 12 Jul 2016 15:14:02 -0400 Message-ID: <1468350842.8843.18.camel@gmail.com> 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> Reply-To: nicolas@ndufresne.ca Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1468350511.8843.16.camel@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Wu-Cheng Li =?UTF-8?Q?=28=E6=9D=8E=E5=8B=99=E8=AA=A0=29?= , tiffany lin Cc: 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 Le mardi 12 juillet 2016 =C3=A0 15:08 -0400, Nicolas Dufresne a =C3=A9c= rit=C2=A0: > 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=C2=A0: > > 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. Right? > > 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 similarities > between what vendor like to call their proprietary formats. Doing the > 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. Here's the kind of information we want in the documentation. https://chromium.googlesource.com/chromium/src/media/+/master/base/vide o_types.h#40 =C2=A0 // MediaTek proprietary format. MT21 is similar to NV21 except t= he memory =C2=A0 // layout and pixel layout (swizzles). 12bpp with Y plane follow= ed by a 2x2 =C2=A0 // interleaved VU plane. Each image contains two buffers -- Y pl= ane and VU =C2=A0 // plane. Two planes can be non-contiguous in memory. The starti= ng addresses =C2=A0 // of Y plane and VU plane are 4KB alignment. =C2=A0 // Suppose image dimension is (width, height). For both Y plane = and VU plane: =C2=A0 // Row pitch =3D ((width+15)/16) * 16. =C2=A0 // Plane size =3D Row pitch * (((height+31)/32)*32) Now obviously this is incomplete, as the swizzling need to be documente= d of course. >=20 > regards, > Nicolas