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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, 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 7200EC76191 for ; Thu, 18 Jul 2019 08:39:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 40C51208C0 for ; Thu, 18 Jul 2019 08:39:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=baylibre-com.20150623.gappssmtp.com header.i=@baylibre-com.20150623.gappssmtp.com header.b="OLJAlKAm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726423AbfGRIjT (ORCPT ); Thu, 18 Jul 2019 04:39:19 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:45442 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726386AbfGRIjT (ORCPT ); Thu, 18 Jul 2019 04:39:19 -0400 Received: by mail-wr1-f68.google.com with SMTP id f9so27668182wre.12 for ; Thu, 18 Jul 2019 01:39:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=VI6zbqshE7YIwzb8pijkEdmKe3OXMlQdJNQym4wfXL8=; b=OLJAlKAm72glM99/OzAMp3PsszgyODQAemGKTQfQajEpdDactkcyCrwfzwQ0imau7h rzCRpFgDVsBXp6WB/k+pvmZbkbv9/I7KJlL/Eb1weOMPGERrVjag83C778EEJYRHtu3W t2Qo1E3Tr/93S8/w34o68ET1tp3bmQupG+DBnz4Vp5ZNcRMsj1tZZmqPshAjoMD28J+8 Tv6xv43zwkJrQE8KqNxmfAjz/DW1lGQEv3G2MqQIuq6ROMLoE2VXcd0Kbbu3Pc4antDx 1rpchpIa0Km14wlTK7M3Cel1oZjk8XDuHq83l5ksENhjnvJkB4X2JAUIFUXm1H++SQDs y5JA== 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=VI6zbqshE7YIwzb8pijkEdmKe3OXMlQdJNQym4wfXL8=; b=O5XIb+ZdLTb7f/j5iP+nvaFnW/AzIxCBLsMkbUBhXOj9OqrCZiwgK6mTumbyTIWUBv SDHvzBzQPusaONoLu4eHd6quvSRwTZHEJ7xfqM5ILqmZGmI1Mk0r3No0ZSOrrzHz/iG7 JqFsIoGrZNh62B8caKkyuyYk6WR0p4UU3rk/15LUoHrDcBqOfBBbsmtRP7VQk83gCi0s MPVT7foc0fWcUJuP28U1gUOXhY/kgpatqJ3iTr/93mNC5qOBjyMALcTMDE8J9oexkJaI ToIedk03Jg5WBWIMSNBWG9gVrxflVmldydFip99KKyiI89gRfxHPk+A+nJLqzgK33hWN xZgg== X-Gm-Message-State: APjAAAVSz8bQpm7p1qO/xqfTkKDTkft7LzTC/MmhS4SF6cfNtr9KRVeC /6x0jK1JWezt4yamThmnl5upaISvuq6IiaYunFCJMg== X-Google-Smtp-Source: APXvYqwaZAlruB32oDa9JnT2jKDJSom5y1u8eIUjfUY0f6A3bFyFXvWCk6uKAqtBu15JNn4xvG4aVFy1diIhfXVhE4w= X-Received: by 2002:a5d:528d:: with SMTP id c13mr47488133wrv.247.1563439157199; Thu, 18 Jul 2019 01:39:17 -0700 (PDT) MIME-Version: 1.0 References: <20190609143820.4662-1-mjourdan@baylibre.com> <907e0560-3b46-04c9-52ef-6c6ff7140876@xs4all.nl> <3dc4d551-0628-5c74-c223-4afe64a701d8@xs4all.nl> In-Reply-To: <3dc4d551-0628-5c74-c223-4afe64a701d8@xs4all.nl> From: Maxime Jourdan Date: Thu, 18 Jul 2019 10:39:06 +0200 Message-ID: Subject: Re: [RFC PATCH 0/5] Add enum_fmt flag for coded formats with dynamic resolution switching To: Hans Verkuil Cc: Hans Verkuil , Mauro Carvalho Chehab , Tomasz Figa , Linux Media Mailing List , Laurent Pinchart , Stanimir Varbanov , Tiffany Lin , Andrew-CT Chen , Kyungmin Park , Kamil Debski , Jeongtae Park , Andrzej Hajda 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 Mon, Jul 15, 2019 at 2:37 PM Hans Verkuil wrote: > > On 6/11/19 10:13 AM, Hans Verkuil wrote: > > On 6/9/19 4:38 PM, Maxime Jourdan wrote: > >> Hello, > >> > >> This RFC proposes a new format flag - V4L2_FMT_FLAG_DYN_RESOLUTION - used > >> to tag coded formats for which the device supports dynamic resolution > >> switching, via V4L2_EVENT_SOURCE_CHANGE. > >> This includes the initial "source change" where the device is able to > >> tell userspace about the coded resolution and the DPB size (which > >> sometimes translates to V4L2_CID_MIN_BUFFERS_FOR_CAPTURE). > > > > Shouldn't the initial source change still be there? The amlogic decoder > > is capable of determining the resolution of the stream, right? It just > > can't handle mid-stream changes. > > I've been thinking about this a bit more: there are three different HW capabilities: > > 1) The hardware cannot parse the resolution at all and userspace has to tell it > via S_FMT. > > 2) The hardware can parse the initial resolution, but is not able to handle > mid-stream resolution changes. > > 3) The hardware can parse the initial resolution and all following mid-stream > resolution changes. > > We can consider 2 the default situation. > > In case of 1 the SOURCE_CHANGE event is absent and userspace cannot subscribe > to it. Question: do we want to flag this with the format as well? I.e. with a > V4L2_FMT_FLAG_MANUAL_RESOLUTION? I think just not implementing the SOURCE_CHANGE > event (and documenting this) is sufficient. > I think that not implementing SOURCE_CHANGE is sufficient as well. The issue (in my case), is that the amlogic decoder _does_ support the event (case 3) for anything recent (H264, HEVC, VP9), but not for e.g MPEG 1/2 (case 1). A possible solution would be to create 2 separate devices, one implementing the event, the other not. Do you think this is reasonable ? This would discard the need for all the proposed flags, unless there are other decoder drivers that fall in case 2. > In case of 3 the format sets the V4L2_FMT_FLAG_DYN_RESOLUTION flag. > > What do you think? > > Regards, > > Hans > > > > > Regards, > > > > Hans > > > >> This flag is mainly aimed at stateful decoder drivers. > >> > >> This RFC is motivated by my development on the amlogic video decoder > >> driver, which does not support dynamic resolution switching for older > >> coded formats (MPEG 1/2, MPEG 4 part II, H263). It does however support > >> it for the newer formats (H264, HEVC, VP9). > >> > >> The specification regarding stateful video decoders should be amended > >> to include that, in the absence of this flag for a certain format, > >> userspace is expected to extract the coded resolution and allocate > >> a sufficient amount of capture buffers on its own. > >> I understand that this point may be tricky, since older kernels with > >> close-to-spec drivers would not have this flag available, yet would > >> fully support dynamic resolution switching. > >> However, with the spec not merged in yet, I wanted to have your opinion > >> on this late addition. > >> > >> The RFC patches also adds support for this flag for the 4 following > >> stateful decoder drivers: > >> - venus > >> - s5p-mfc > >> - mtk-vcodec > >> - vicodec > >> > >> Maxime Jourdan (5): > >> media: videodev2: add V4L2_FMT_FLAG_DYN_RESOLUTION > >> media: venus: vdec: flag OUTPUT formats with > >> V4L2_FMT_FLAG_DYN_RESOLUTION > >> media: s5p_mfc_dec: flag OUTPUT formats with > >> V4L2_FMT_FLAG_DYN_RESOLUTION > >> media: mtk-vcodec: flag OUTPUT formats with > >> V4L2_FMT_FLAG_DYN_RESOLUTION > >> media: vicodec: flag vdec/stateful OUTPUT formats with > >> V4L2_FMT_FLAG_DYN_RESOLUTION > >> > >> Documentation/media/uapi/v4l/vidioc-enum-fmt.rst | 7 +++++++ > >> drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c | 4 ++++ > >> drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h | 1 + > >> drivers/media/platform/qcom/venus/core.h | 1 + > >> drivers/media/platform/qcom/venus/vdec.c | 11 +++++++++++ > >> drivers/media/platform/s5p-mfc/s5p_mfc_common.h | 1 + > >> drivers/media/platform/s5p-mfc/s5p_mfc_dec.c | 13 +++++++++++++ > >> drivers/media/platform/vicodec/vicodec-core.c | 2 ++ > >> include/uapi/linux/videodev2.h | 5 +++-- > >> 9 files changed, 43 insertions(+), 2 deletions(-) > >> > > >