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[209.85.221.47]) by smtp.gmail.com with ESMTPSA id h50sm108539eda.51.2019.11.07.23.58.19 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 07 Nov 2019 23:58:19 -0800 (PST) Received: by mail-wr1-f47.google.com with SMTP id p4so5879713wrm.8 for ; Thu, 07 Nov 2019 23:58:19 -0800 (PST) X-Received: by 2002:a5d:414a:: with SMTP id c10mr7470082wrq.100.1573199898916; Thu, 07 Nov 2019 23:58:18 -0800 (PST) MIME-Version: 1.0 References: <20191105191919.167345-1-dmitry.sepp@opensynergy.com> <20191107095657.72dlxzm4uz7ndkek@sirius.home.kraxel.org> <1573181413.STYvEGL1rf@os-lin-dmo> <20191108074955.t7mtqks4dfmrdzod@sirius.home.kraxel.org> In-Reply-To: <20191108074955.t7mtqks4dfmrdzod@sirius.home.kraxel.org> From: Tomasz Figa Date: Fri, 8 Nov 2019 16:58:08 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [virtio-dev] [RFC RESEND] virtio-video: Add virtio video device specification To: Gerd Hoffmann Cc: Dmitry Sepp , virtio-dev@lists.oasis-open.org, Linux Media Mailing List , Keiichi Watanabe , Alexandre Courbot , alexlau@chromium.org, dgreid@chromium.org, =?UTF-8?Q?St=C3=A9phane_Marchesin?= , Pawel Osciak , David Stevens , Hans Verkuil , Daniel Vetter Content-Type: text/plain; charset="UTF-8" Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On Fri, Nov 8, 2019 at 4:50 PM Gerd Hoffmann wrote: > > On Thu, Nov 07, 2019 at 02:09:34PM +0100, Dmitry Sepp wrote: > > Hello Gerd, > > > > Thank you for your feedback. > > > > There is no relationship between those. As I mentioned earlier. we have also > > been working on a virtio video device at the same time. And there is no > > relationship between the two specs. > > Keiichi, have you looked at the spec? > > I think it is useful to have a single device specification for all video > functions given that there is a bunch of common stuff. Both encoder and > decoder must negotiate video frame and video stream parameters for > example. Also the virtio-video spec looks like a superset of > virtio-vdec. > > Is there any important feature in video-vdec which is missing in > virtio-video? > I just replied to Dmitry's email with further clarification on some vdec aspects and rationale behind some of the design decisions. Please take a look. I think it should be possible to build one protocol for both decoding and encoding. Actually virtio-vdec shouldn't need too much modification to handle encoding. The ability to set operating mode (decoder vs encoder) and set frame buffer format should be enough. However I believe that making it as generic as virtio-video adds too much complexity, increasing the possible attack surface and making it difficult to validate. Best regards, Tomasz From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-6304-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 CB614985F34 for ; Fri, 8 Nov 2019 07:58:21 +0000 (UTC) MIME-Version: 1.0 References: <20191105191919.167345-1-dmitry.sepp@opensynergy.com> <20191107095657.72dlxzm4uz7ndkek@sirius.home.kraxel.org> <1573181413.STYvEGL1rf@os-lin-dmo> <20191108074955.t7mtqks4dfmrdzod@sirius.home.kraxel.org> In-Reply-To: <20191108074955.t7mtqks4dfmrdzod@sirius.home.kraxel.org> From: Tomasz Figa Date: Fri, 8 Nov 2019 16:58:08 +0900 Message-ID: Content-Type: text/plain; charset="UTF-8" Subject: Re: [virtio-dev] [RFC RESEND] virtio-video: Add virtio video device specification To: Gerd Hoffmann Cc: Dmitry Sepp , virtio-dev@lists.oasis-open.org, Linux Media Mailing List , Keiichi Watanabe , Alexandre Courbot , alexlau@chromium.org, dgreid@chromium.org, =?UTF-8?Q?St=C3=A9phane_Marchesin?= , Pawel Osciak , David Stevens , Hans Verkuil , Daniel Vetter List-ID: On Fri, Nov 8, 2019 at 4:50 PM Gerd Hoffmann wrote: > > On Thu, Nov 07, 2019 at 02:09:34PM +0100, Dmitry Sepp wrote: > > Hello Gerd, > > > > Thank you for your feedback. > > > > There is no relationship between those. As I mentioned earlier. we have also > > been working on a virtio video device at the same time. And there is no > > relationship between the two specs. > > Keiichi, have you looked at the spec? > > I think it is useful to have a single device specification for all video > functions given that there is a bunch of common stuff. Both encoder and > decoder must negotiate video frame and video stream parameters for > example. Also the virtio-video spec looks like a superset of > virtio-vdec. > > Is there any important feature in video-vdec which is missing in > virtio-video? > I just replied to Dmitry's email with further clarification on some vdec aspects and rationale behind some of the design decisions. Please take a look. I think it should be possible to build one protocol for both decoding and encoding. Actually virtio-vdec shouldn't need too much modification to handle encoding. The ability to set operating mode (decoder vs encoder) and set frame buffer format should be enough. However I believe that making it as generic as virtio-video adds too much complexity, increasing the possible attack surface and making it difficult to validate. Best regards, Tomasz --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org