From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0B90C432C0 for ; Thu, 21 Nov 2019 10:55:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7C38A20715 for ; Thu, 21 Nov 2019 10:55:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726342AbfKUKzG (ORCPT ); Thu, 21 Nov 2019 05:55:06 -0500 Received: from plasma31.jpberlin.de ([80.241.56.82]:44753 "EHLO plasma31.jpberlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726170AbfKUKzF (ORCPT ); Thu, 21 Nov 2019 05:55:05 -0500 Received: from spamfilter05.heinlein-hosting.de (spamfilter05.heinlein-hosting.de [80.241.56.123]) by plasma.jpberlin.de (Postfix) with ESMTP id 311E5100AAB; Thu, 21 Nov 2019 11:55:00 +0100 (CET) X-Virus-Scanned: amavisd-new at heinlein-support.de Received: from plasma.jpberlin.de ([80.241.56.76]) by spamfilter05.heinlein-hosting.de (spamfilter05.heinlein-hosting.de [80.241.56.123]) (amavisd-new, port 10030) with ESMTP id mWN6jxUF2glb; Thu, 21 Nov 2019 11:54:59 +0100 (CET) Received: from webmail.opensynergy.com (unknown [217.66.60.5]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (Client CN "webmail.opensynergy.com", Issuer "GeoTrust EV RSA CA 2018" (not verified)) (Authenticated sender: opensynergy@jpberlin.de) by plasma.jpberlin.de (Postfix) with ESMTPSA id 80B5D10077C; Thu, 21 Nov 2019 11:54:58 +0100 (CET) Received: from os-lin-dmo.localnet (10.25.255.1) by MXS01.open-synergy.com (10.25.10.17) with Microsoft SMTP Server (TLS) id 14.3.468.0; Thu, 21 Nov 2019 11:54:57 +0100 From: Dmitry Sepp To: CC: Gerd Hoffmann , Keiichi Watanabe , Tomasz Figa , "Linux Media Mailing List" , Alexandre Courbot , Alex Lau , Dylan Reid , =?ISO-8859-1?Q?St=E9phane?= Marchesin , Pawel Osciak , David Stevens , Hans Verkuil , Daniel Vetter Subject: Re: [virtio-dev] [RFC RESEND] virtio-video: Add virtio video device specification Date: Thu, 21 Nov 2019 11:54:57 +0100 Message-ID: <7736193.Whgddqjo8n@os-lin-dmo> Organization: OpenSynergy In-Reply-To: <20191120112929.gvsne7ykvcyw65lu@sirius.home.kraxel.org> References: <20191105191919.167345-1-dmitry.sepp@opensynergy.com> <20191120112929.gvsne7ykvcyw65lu@sirius.home.kraxel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Originating-IP: [10.25.255.1] Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Gerd, On Mittwoch, 20. November 2019 12:29:29 CET Gerd Hoffmann wrote: > Hi, > > > > > > 3. No support for getting plane requirements from the device (sg vs > > > > > contig, > > > > > size, stride alignment, plane count). > > > > > > > > There is actually a bigger difference that results in that. Vdec > > > > assumes host-allocated buffers coming from a different device, e.g. > > > > virtio-gpu and the host having the right knowledge to allocate the > > > > buffers correctly. This is related to the fact that it's generally > > > > difficult to convey all the allocation constraints in a generic > > > > manner. > > > > > > Yep, buffer handling is tricky, especially when it comes to decoding > > > directly to gpu buffers and also when supporting playback of > > > drm-protected streams where the guest might not be allowed to access > > > the stream data. > > > > Also, if we decide to have a buffer sharing device as Gerd suggested > > in a different thread, > > we'll get less overlaps between video codec feature and camera feature. > > e.g. VIRTIO_VIDEO_T_RESOURCE_* would be simplified. (or removed?) > > Disclaimer: Havn't found the time yet to go over both virtio-video and > virtio-vdec in detail. > > > As Tomasz said, I think virtio-vdec can be modified to support > > encoding as well without big changes. I'm happy to update our > > protocol and driver implementation to support encoding if needed. > > I think it makes sense to have a rough plan first ;) > Is there a virtio-video implementation too? Yes, of course. We will be ready to share the code very soon. Regards, Dmitry. > > When it comes to buffer handling: I don't like that virtio-vdec depends > on virtio-gpu for buffer handling. Allowing sharing buffers between > virtio-vdec and virtio-gpu (and possibly other devices) makes sense as > an optional extension. But IMO the encoder/decoder device should be > able to operate as stand-alone device. > > cheers, > Gerd > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org > For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org