From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-6940-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id B5757985FDD for ; Thu, 12 Mar 2020 10:29:44 +0000 (UTC) From: Dmitry Sepp Date: Thu, 12 Mar 2020 11:29:38 +0100 Message-ID: <1799967.VLH7GnMWUR@os-lin-dmo> In-Reply-To: <1ac18708-262f-c751-d955-267931270028@xs4all.nl> References: <20200218202753.652093-1-dmitry.sepp@opensynergy.com> <1ac18708-262f-c751-d955-267931270028@xs4all.nl> MIME-Version: 1.0 Subject: [virtio-dev] Re: [PATCH v2 0/1] Virtio Video V4L2 driver Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable To: Keiichi Watanabe , Hans Verkuil Cc: Linux Media Mailing List , virtio-dev@lists.oasis-open.org, Alexandre Courbot , Alex Lau , Daniel Vetter , Dylan Reid , David Staessens , Enrico Granata , Frediano Ziglio , Gerd Hoffmann , =?ISO-8859-1?Q?St=E9phane?= Marchesin , Pawel Osciak , spice-devel@lists.freedesktop.org, David Stevens , Tomasz Figa , uril@redhat.com, Samiullah Khawaja , Kiran Pawar List-ID: Hi Hans, I'm not sure about crosvm, for us it is probably still feasible to implemen= t=20 FWHT in the device (but it is unfortunately not supposed to be upstreamed= =20 yet). The main question is what would be the proper user-space tool to test that?= Is=20 v4l2-ctl OK for that? As for gstreamer, AFAIK it does not respect the v4l2= =20 Video Decoder Interface Spec and we have seen some issues with it. Best regards, Dmitry. On Donnerstag, 12. M=E4rz 2020 10:54:35 CET Hans Verkuil wrote: > On 3/12/20 10:49 AM, Keiichi Watanabe wrote: > > Hi Hans, > >=20 > > On Wed, Mar 11, 2020 at 10:26 PM Hans Verkuil wrot= e: > >> Hi Dmitry, > >>=20 > >> On 2/18/20 9:27 PM, Dmitry Sepp wrote: > >>> Hi all, > >>>=20 > >>> This is a v4l2 virtio video driver for the virtio-video device > >>> specification v3 [1]. > >>>=20 > >>> The first version of the driver was introduced here [2]. > >>>=20 > >>> Changes v1 -> v2: > >>> * support the v3 spec (mostly) > >>> * add a module parameter to ask for pages from ZONE_DMA > >>>=20 > >>> What is not implemented: > >>> * Plane layout flags should be used to propagate number of planes to > >>>=20 > >>> user-space > >>>=20 > >>> * There is no real use of stream creation with bitstream format in th= e > >>>=20 > >>> parameter list. The driver just uses the first bitstream format fro= m > >>> the list. > >>>=20 > >>> * Setting bitrate is done in a different way compared to the spec. Th= is > >>>=20 > >>> is because it has been already agreed on that the way the spec > >>> currently describes it requires changes. > >>>=20 > >>> Potential improvements: > >>> * Do not send stream_create from open. Use corresponding state machin= e > >>>=20 > >>> condition to do this. > >>>=20 > >>> * Do not send stream_destroy from close. Do it in reqbufs(0). > >>> * Cache format and control settings. Reduce calls to the device. > >>=20 > >> Some general notes: > >>=20 > >> Before this can be merged it needs to pass v4l2-compliance. > >>=20 > >> I also strongly recommend adding support for V4L2_PIX_FMT_FWHT to > >> allow testing with the vicodec emulation driver. This will also > >> allow testing all sorts of corner cases without requiring special > >> hardware. > >=20 > > I agree that it's great if we could test virtio-video with vicodec, > > but I wonder if supporting FWHT is actually needed for the initial > > patch. > > Though it wouldn't be difficult to support FWHT in the driver, we also > > needs to support it in the host's hypervisor to test it. It's not easy > > for our hypervisor to support FWHT, as it doesn't talk to v4l2 driver > > directly. > > Without the host-side implementation, it makes no sense to support it. > > Also, if we support FWHT, we should have the format in a list of > > supported formats in the virtio specification. However, I'm not sure > > if FWHT is a general codec enough to be added in the spec, which > > shouldn't be specific to Linux. >=20 > Good point, I didn't know that. >=20 > Is it possible to add support for FWHT under a linux debug/test option? >=20 > It's really the main reason for having this, since you would never use > this in production code. But it is so nice to have for regression testing= . >=20 > Regards, >=20 > =09Hans >=20 > > Best regards, > > Keiichi > >=20 > >> Regards, > >>=20 > >> Hans > >>>=20 > >>> Best regards, > >>> Dmitry. > >>>=20 > >>> [1] https://markmail.org/message/dmw3pr4fuajvarth > >>> [2] https://markmail.org/message/wnnv6r6myvgb5at6 --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org