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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 09702C282DD for ; Wed, 8 Jan 2020 13:51:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C791D206DA for ; Wed, 8 Jan 2020 13:51:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="QvhtXlgw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728391AbgAHNvN (ORCPT ); Wed, 8 Jan 2020 08:51:13 -0500 Received: from mail-lj1-f193.google.com ([209.85.208.193]:33629 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727158AbgAHNvM (ORCPT ); Wed, 8 Jan 2020 08:51:12 -0500 Received: by mail-lj1-f193.google.com with SMTP id y6so3443901lji.0 for ; Wed, 08 Jan 2020 05:51:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=j2tbKyq2TJuMrRgt3tLabvZZ7HDbQHaIINM/EQteRrE=; b=QvhtXlgwALbRSIkFIh+z8nhyio+0jkI8xfs2zTf2Vk+w5YCHv6RFeXYrHcoqreGyfN keKfDlQxzWDLUPrrXuxjo7qlVy7kPkZEqorZ46fcP4oj4PmgIOQRqFc4OdT1MrOGYVVH fFqHLpQhtz/arlwgBv2VFJrvZHENZn49U7m9c= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=j2tbKyq2TJuMrRgt3tLabvZZ7HDbQHaIINM/EQteRrE=; b=iszkCBFhDTLagSlfMANP8fZFFdorF8EzPyEE6tRNDl57PMv/hZutmDLw6yqbqovEwz uCr6DKmOj1LfWYyxFr6aXmiIYz8VYsg/wD+1puCsbOXMI76fH1KAFyBJ5CF7W0dndB7B 9X67PVyfBQC7OwgFU7ov1f/qfA24P4PQS4upNu2vjQik+QJSU2oo6rhrrLLJBcaV6Abq J8H/2PtH6j16kJxGQ1FsqsW0l4A9OFI+k+lKZWYksjaeVp8ZCUrPJEDFGu+q/YTJ1+X3 KykHBM9eMqMDK8tKqon13rGPOXCA2qOlfkMyt4alTVLUqmC5NI58aFdh0wdr51xPhQmc wGkg== X-Gm-Message-State: APjAAAVAOLTBQlbVw7RpfOSATFpcSVdfy8Z7oLHHGnpev4D2WHQ/KX3x cniiMGTyU7ZYlZJQRz9Oz+F2WybyMsaOHFEIih/omw== X-Google-Smtp-Source: APXvYqzAqTuo6bT4pNcKKL/sbaXHTO9l8rt9Z1w/LBzLQ0DT4qTftXan2TkzSFVCaphzTNcDj/6OZOE97YR+mLjrQw0= X-Received: by 2002:a2e:9cd8:: with SMTP id g24mr2921078ljj.243.1578491470700; Wed, 08 Jan 2020 05:51:10 -0800 (PST) MIME-Version: 1.0 References: <20191218130214.170703-1-keiichiw@chromium.org> <20191219074639.kdkrqxwb6fdb67hu@sirius.home.kraxel.org> <3550989.gzE5nMqd4t@os-lin-dmo> <20191219130158.7rzdkyemupreudko@sirius.home.kraxel.org> In-Reply-To: <20191219130158.7rzdkyemupreudko@sirius.home.kraxel.org> From: Keiichi Watanabe Date: Wed, 8 Jan 2020 22:50:59 +0900 Message-ID: Subject: Re: [virtio-dev] Re: [PATCH v2 1/1] virtio-video: Add virtio video device specification To: Gerd Hoffmann Cc: Dmitry Sepp , Tomasz Figa , virtio-dev@lists.oasis-open.org, Linux Media Mailing List , Alexandre Courbot , Alex Lau , Daniel Vetter , Dylan Reid , Enrico Granata , Frediano Ziglio , Hans Verkuil , =?UTF-8?Q?St=C3=A9phane_Marchesin?= , Pawel Osciak , spice-devel@lists.freedesktop.org, David Stevens , uril@redhat.com 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 Hi Gerd, Thank you so much for the review. I'm sorry for not replying earlier. On Thu, Dec 19, 2019 at 10:02 PM Gerd Hoffmann wrote: > > Hi, > > > > Not clearly defined in the spec: When is the decoder supposed to send > > > the response for a queue request? When it finished decoding (i.e. frame > > > is ready for playback), or when it doesn't need the buffer any more for > > > decoding (i.e. buffer can be re-queued or pages can be released)? The answer is "when it doesn't need the buffer any more for decoding". The device can access buffer contents from when a queue request is sent until the device responds it. So, the device must not responds a queue request before finishing all process that requires the buffer content. Actually, the first one "When it finished decoding (i.e. frame is ready for playback)" doesn't make much sense, as it's not necessary to have a one-to-one correspondence between an input bitstream buffer and a decoded frame. It's okay to decode one input buffer contains bitstream data for two frames. Also, a user can pass bitstream for one frame as two input buffers. I'll document it in the spec. Best regards, Keiichi > > In my eyes the both statements mean almost the same and both are valid. > > Well, no. When the device decoded a P-Frame it can notify the device, > saying "here is your decoded frame". But the device might still need > the buffer with the decoded frame to properly decode the following B/I > Frames which reference the P-Frame. > > cheers, > Gerd > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-6625-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 0CF62985E06 for ; Wed, 8 Jan 2020 13:51:12 +0000 (UTC) MIME-Version: 1.0 References: <20191218130214.170703-1-keiichiw@chromium.org> <20191219074639.kdkrqxwb6fdb67hu@sirius.home.kraxel.org> <3550989.gzE5nMqd4t@os-lin-dmo> <20191219130158.7rzdkyemupreudko@sirius.home.kraxel.org> In-Reply-To: <20191219130158.7rzdkyemupreudko@sirius.home.kraxel.org> From: Keiichi Watanabe Date: Wed, 8 Jan 2020 22:50:59 +0900 Message-ID: Subject: Re: [virtio-dev] Re: [PATCH v2 1/1] virtio-video: Add virtio video device specification Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable To: Gerd Hoffmann Cc: Dmitry Sepp , Tomasz Figa , virtio-dev@lists.oasis-open.org, Linux Media Mailing List , Alexandre Courbot , Alex Lau , Daniel Vetter , Dylan Reid , Enrico Granata , Frediano Ziglio , Hans Verkuil , =?UTF-8?Q?St=C3=A9phane_Marchesin?= , Pawel Osciak , spice-devel@lists.freedesktop.org, David Stevens , uril@redhat.com List-ID: Hi Gerd, Thank you so much for the review. I'm sorry for not replying earlier. On Thu, Dec 19, 2019 at 10:02 PM Gerd Hoffmann wrote: > > Hi, > > > > Not clearly defined in the spec: When is the decoder supposed to sen= d > > > the response for a queue request? When it finished decoding (i.e. fr= ame > > > is ready for playback), or when it doesn't need the buffer any more f= or > > > decoding (i.e. buffer can be re-queued or pages can be released)? The answer is "when it doesn't need the buffer any more for decoding". The device can access buffer contents from when a queue request is sent until the device responds it. So, the device must not responds a queue request before finishing all process that requires the buffer content. Actually, the first one "When it finished decoding (i.e. frame is ready for playback)" doesn't make much sense, as it's not necessary to have a one-to-one correspondence between an input bitstream buffer and a decoded frame. It's okay to decode one input buffer contains bitstream data for two frames. Also, a user can pass bitstream for one frame as two input buffers. I'll document it in the spec. Best regards, Keiichi > > In my eyes the both statements mean almost the same and both are valid. > > Well, no. When the device decoded a P-Frame it can notify the device, > saying "here is your decoded frame". But the device might still need > the buffer with the decoded frame to properly decode the following B/I > Frames which reference the P-Frame. > > 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