From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9556942EEA9 for ; Tue, 28 Apr 2026 12:30:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777379468; cv=none; b=KrJBzPzpNGwyEu2Bki8JqplabqyG0SyUXVPwhrhvKLjU4UIb/JZsnRGCjcu0WqyVUPC1kb0BtiELWHs6CKbBQUrCTTljbF/AQWWLSBMtnenITZMPcpENKIXPdEQ+eFjB4+Yc2xzGtEnQJyr/YEaalmeKAexEommVYhgnSfaLgd8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777379468; c=relaxed/simple; bh=xeA/BlOuScO4vMUN9JHx3pOB4WhKg+rEfOaMtx/NABY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TcmxRHkIXLp+1quLixdg7G/L8nKcvtRGdD/z5IDBH6ABLMjt9lPeHU0/s8RfOYpc7vWlbR3UYr77qgeGA9Q03tDks5km56yLkm/sGgLErGLAZJKc4C4hGks3zKaJnlLaQyiAAURomCNDfNgAMAzmrI8AfTfUPO88Dh0kM4qBGK0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=ik8QAJKg; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="ik8QAJKg" Received: from ideasonboard.com (mob-109-113-69-223.net.vodafone.it [109.113.69.223]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 25928E91; Tue, 28 Apr 2026 14:29:08 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1777379348; bh=xeA/BlOuScO4vMUN9JHx3pOB4WhKg+rEfOaMtx/NABY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ik8QAJKgA3TofYTKBlqjUVczEAevZ6E566qhlRIzE78FwH8aZUXHGIaM1TgvRVtlh L2Nn1SCms8mq1fIRk+XqCmGvr4WL2bq01qVBo7+WLhEr9o6jSc6TWo1/liNajwOrhU SM+KLzS6WIy4mlPvWq4a6llEk0GV7YMMZUYqN4Nk= Date: Tue, 28 Apr 2026 14:30:47 +0200 From: Jacopo Mondi To: Laurent Pinchart Cc: Loic Poulain , Michael Riesch , Ricardo Ribalda , Hans Verkuil , Nicolas Dufresne , Linux Media Mailing List , Mauro Carvalho Chehab , Sean Young , Sakari Ailus , Jacopo Mondi , Niklas =?utf-8?Q?S=C3=B6derlund?= , Tomi Valkeinen , Alain Volmat , Bryan O'Donoghue , Dave Stevenson , Daniel Almeida , Michael Tretter , Tomasz Figa , Steve Cho , Kieran Bingham , Kevin Hilman , Paul Kocialkowski , Benjamin Mugnier , Hans de Goede , Maxime Ripard , Brandon Brnich , Marco Felsch , Sven =?utf-8?Q?P=C3=BCschel?= , Devarsh Thakkar , Yemike Abhilash Chandra , Jackson Lee , Jai Luthra , Mehdi Djait , "Padhi, Beleswar" , "Donadkar, Rishikesh" , Rouven Czerwinski , Nayden Kanchev , Konstantin Babin , Anthony McGivern Subject: Re: [ANNv4] Media Summit on May 26th in Nice, France Message-ID: References: <20260413201907.GD4034@killaraus.ideasonboard.com> <20260413211602.GE4034@killaraus.ideasonboard.com> <420e20b3-4264-4ab0-bb50-1ae60f6c837a@collabora.com> <20260414074230.GB4061@killaraus.ideasonboard.com> <20260414084259.GC4061@killaraus.ideasonboard.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260414084259.GC4061@killaraus.ideasonboard.com> Hello On Tue, Apr 14, 2026 at 11:42:59AM +0300, Laurent Pinchart wrote: > On Tue, Apr 14, 2026 at 10:34:13AM +0200, Loic Poulain wrote: > > On Tue, Apr 14, 2026 at 9:42 AM Laurent Pinchart wrote: > > > On Tue, Apr 14, 2026 at 09:20:56AM +0200, Michael Riesch wrote: > > > > On 4/14/26 08:55, Ricardo Ribalda wrote: > > > > > On Tue, 14 Apr 2026 at 08:47, Hans Verkuil wrote: > > > > >> On 13/04/2026 23:16, Laurent Pinchart wrote: > > > > >>> On Mon, Apr 13, 2026 at 04:25:54PM -0400, Nicolas Dufresne wrote: > > > > >>>> Le lundi 13 avril 2026 à 23:19 +0300, Laurent Pinchart a écrit : > > > > >>>>> On Mon, Apr 13, 2026 at 10:03:52PM +0200, Loic Poulain wrote: > > > > >>>>>> Hi Hans, > > > > >>>>>> > > > > >>>>>> I would be happy to discuss this if a slot is available: > > > > >>>>>> > > > > >>>>>> Title: Generic V4L2 ISP M2M framework > > > > >>>>>> Presenter: Loic Poulain > > > > >>>>>> Time estimate: ~20min > > > > >>>>>> Description: During early development of a Qualcomm Offline Image > > > > >>>>>> Processing Engine (OPE), we relied on the V4L2 memory‑to‑memory > > > > >>>>>> (v4l2‑m2m) framework, which is widely used and provides solid support > > > > >>>>>> for buffer management and scheduling. However, applying it to an ISP > > > > >>>>>> use case exposes limitations: ISP engines often require a richer media > > > > >>>>>> graph, with multiple pads and metadata flows, similar to inline ISP > > > > >>>>>> pipelines (params, stats, outputs). This talk proposes discussing the > > > > >>>>>> need for and design of a common V4L2 ISP M2M framework to factor out > > > > >>>>>> shared functionality across drivers, particularly around buffer/queue > > > > >>>>>> management and job scheduling. > > > > > > > > It seems that we share some pain points.. :-) :-/ > > > > > > > > Over the last year, some ideas have been brewing in my mind. Not > > > > necessarily *my* ideas, mind you, rather ideas that have been around in > > > > linux-media for quite a while, actually. What I would like to prepare > > > > for the Media Summit goes along the same lines. > > > > > > > > >>>>> That's well aligned with the v4l2-isp framework that Jacopo started, and > > > > >>>>> to the multi-context and media-jobs APIs that we have proposed. I > > > > >>>>> wonder, however, if a short session at the media summit will be enough, > > > > >>>>> or if we should try to organize a half day brainstorming workshop at > > > > >>>>> some point. Depending on when the people interested in this topic plan > > > > >>>>> to arrive, Monday could be an option. > > > > >>>> > > > > >>>> I'm also/still interested in the multi-context for m2m decoders that have inline > > > > >>>> post-processing capabilities (current model forces us to waste a lot of RAM). We > > > > >>>> just restarted some design discussion with the team, with an increased > > > > >>>> confidence that multi-context is the way. The scheduler could come handy in the > > > > >>>> future if we get to deal with more multi-stage codecs in the future. I'll be in > > > > >>>> Nice all day Monday. > > > > >>> > > > > >>> I will unfortunately be available only until 15:00 on Monday, but Jacopo > > > > >>> should be available through the day. Let's see who would be interested > > > > >>> and available, and try to organize something. > > > > >> > > > > >> I'm available on Monday as well. I think this is a topic that is well suited > > > > >> to a brainstorm session. > > > > > > > > > > I am also available on Monday and would like to attend the session. > > > > > > > > I'd be interested too. Right now the plan is to arrive on Monday > > > > afternoon. Depending on what time you agree on it may work out anyway. > > > > It would be great to know the exact time this session will start (as I > > > > might need to adjust my travel arrangements). > > > > I can arrive on Monday, with a preference for the afternoon. > > > > > We need a volunteer to organize this, as in finding and booking a > > > meeting space. Note that Monday is a public holiday in France (Monday > > > the 25th of May in particular, not all Mondays). > > > > > > If the number of attendees was small I was thinking of hosting the event > > > in the place where the Ideas on Board team will be staying, but it looks > > > like we're already reaching a fair number of people. > > > Are we still considering this BoF session ? We would someone to volunteer organizing this, at @IoB we're quite full for the week and we might have an hard time organizing this one on top of the libcamera workshop. As Laurent said, that Monday is a public holiday in France, and getting a room somewhere might be complicated. We can host some people in the location where we're having the yearly IoB get-together, but you should arrange your travel there (35 minutes from Nice by car). If we get a volunteer we can should maybe a dedicated mail thread as this one was about the Media Summit ? > > > > > Regards! > > > > > > > > > >> The agenda for the media summit is getting quite full, and I agree with Laurent > > > > >> that 20 minutes is likely not enough. If we can so a session on Monday instead, > > > > >> then that would be a good solution. > > > > > > > > Apart from the time and date the scope of this session would be interesting. > > > > > > > > Will this be a birds of a feather session in which the next generation > > > > kernel ISP framework will be discussed? Or even the next generation > > > > kernel video processing framework, where video processing is image > > > > signal processing, encoding/decoding, 2D graphics processing (fisheye > > > > correction units, 2D GPU such as the Rockchip RGA3, ...)? > > > > > > I would focus on Loic's original scope. If the solution can be used for > > > other devices that's great too. I believe that the current multi-context > > > patch series is a good fit for codecs. If we broaden the scope too much > > > right away we'll achieve nothing. > > > > > > > >> I have never been very enthusiastic about the m2m framework: it's fine for e.g. > > > > >> simple scalers, but it's awkward to use for codecs let alone ISPs. > > > > >> > > > > >> I always felt that we really need variants of the m2m framework that are customized > > > > >> to specific use-cases: i.e. a codec m2m framework, and (perhaps) an ISP m2m framework. > > > > >> > > > > >> The big problem with that is of course who will do the work. Making new frameworks > > > > >> is difficult and takes a long time. > > > > A couple of weeks ago, I submitted an initial driver for a Qualcomm > > Offline ISP based on the standard v4l2-m2m framework. Following > > discussions around which parts could be generalized, I started > > migrating this work to a new v4l2-isp-m2m framework: > > (https://github.com/loicpoulain/linux/commit/5d575d7eff8f2371e91d8237148ffdb44b0af5b0). > > I definitely want to discuss this, but I will be available on Monday > until 15:00 only. > > > The API and overall logic closely mirror v4l2-m2m.c, but are extended > > to address ISP‑specific requirements such as multi‑device support and > > multiple queue handling. > > That part I don't like. The V4L2 M2M framework is a big mid-layer that > prevents drivers from having control of how operations are handled. It > does too much, and doesn't give enough flexibility to drivers. It may > have been fine when the framework was designed, for the devices we had > back then, but today it's just painful. I want to turn this around and > give control to the drivers, with helpers they can use to implement > parts that are not driver-specific. This needs to be opt-in, not a layer > that takes completely control between the uAPI and driver operations. > > Let's not reproduce the design mistakes made in the V4L2 M2M framework. > > I also think you need to decouple the context handling and scheduling in > two separate components. They need to work together, but shouldn't be > bundled into a monolithic system. Very importantly, a driver should be > able to implement contexts with the multi-context helpers, and implement > custom scheduling itself. > > > I am planning to submit this work as an RFC > > before the Media Summit. At this stage, the framework is still fairly > > basic and primarily tailored to the Qualcomm use case. There is > > definitely room for improvement, for example, integrating Jacopo’s > > multi‑context support, since for now, the Qualcomm driver simply > > instantiates a single ISP‑M2M context. > > > > As I am still getting familiar with the media subsystem, this work may > > overlap with or conflict with ongoing efforts. Synchronizing seems > > indeed important. Based on my current understanding, there are several > > related areas of work that appear either complementary or orthogonal: > > - Multi‑context support, to instantiate multiple processing sessions > > on shared hardware/driver. > > - Media jobs, to synchronize work across multiple drivers within the > > same media pipeline. > > - ISP M2M, aiming to provide a v4l2-m2m‑like framework specifically > > for memory‑to‑memory ISP devices. > > > > > > This may be naive and overly optimistic, but I feel there is quite a > > > > number of people sharing the same pain points (which are similar to > > > > those Loic pointed out). Maybe (hopefully) this birds of a feather > > > > session leads to the formation of some work group? > > > > > > > > >>>>>> On Sun, Apr 12, 2026 at 12:25 PM Hans Verkuil wrote: > > > > >>>>>>> > > > > >>>>>>> (Please pass this on to anyone you think might be interested in this!) > > > > >>>>>>> > > > > >>>>>>> Hi all, > > > > >>>>>>> > > > > >>>>>>> This is the fourth version of this announcement, updating the list of attendees > > > > >>>>>>> and the tentative agenda at the end: please let me know if you see mistakes. > > > > >>>>>>> Note that there is still time for one or two other topics. Also please check > > > > >>>>>>> the agenda if you need more (or perhaps less) time for your topic. > > > > >>>>>>> > > > > >>>>>>> This year's Media Summit will be held on Tuesday May 26th the day before the > > > > >>>>>>> Embedded Recipes Conference in Nice, France: > > > > >>>>>>> > > > > >>>>>>> https://embedded-recipes.org/2026/ > > > > >>>>>>> > > > > >>>>>>> The Media Summit will be held at Hotel Campanile and in the same meeting room > > > > >>>>>>> as last year (Nikaia): > > > > >>>>>>> > > > > >>>>>>> https://nice-aeroport.campanile.com/en-us/ > > > > >>>>>>> > > > > >>>>>>> It is close to the Airport and to the Embedded Recipes venue. > > > > >>>>>>> > > > > >>>>>>> The meeting room can hold up to 30 people and I will provide video conferencing support, > > > > >>>>>>> just like last year. The location and the meeting room was quite nice last year, so > > > > >>>>>>> I saw no need to change it. > > > > >>>>>>> > > > > >>>>>>> That said, in-person participation is very much preferred. This yearly summit is meant > > > > >>>>>>> for active media developers to meet face-to-face and to discuss media subsystem issues. > > > > >>>>>>> > > > > >>>>>>> And it is also a good opportunity to talk to each other during the Embedded Recipes > > > > >>>>>>> conference to discuss topics in a smaller group. But if you are an active media developer > > > > >>>>>>> and are really not able to attend in person, then remote participation is an option. > > > > >>>>>>> > > > > >>>>>>> If you want to attend the meeting (either in person or remote), then send an email to me > > > > >>>>>>> directly. The deadline for in-person attendance is May 14 as the hotel needs to know the > > > > >>>>>>> final number of attendees by then. > > > > >>>>>>> > > > > >>>>>>> There is no registration fee, the meeting room is sponsored by Cisco and Collabora, and > > > > >>>>>>> the lunch is sponsored by Ideas on Board! Many thanks to our sponsors, it's very much > > > > >>>>>>> appreciated. > > > > >>>>>>> > > > > >>>>>>> If you have a topic that you want to discuss, just 'Reply All' to this announcement > > > > >>>>>>> and give the topic title, a short description and a guesstimate of the time you need > > > > >>>>>>> for your topic. > > > > >>>>>>> > > > > >>>>>>> See last year's Media Summit Report as an example of what to expect: > > > > >>>>>>> > > > > >>>>>>> https://lore.kernel.org/linux-media/21769183-ca57-4f8f-818a-6a1ad089298d@jjverkuil.nl/ > > > > >>>>>>> > > > > >>>>>>> Regards, > > > > >>>>>>> > > > > >>>>>>> Hans > > > > >>>>>>> > > > > >>>>>>> PS: Be aware that May 24 and 25 are public holidays in France. So many > > > > >>>>>>> shops may be > > > > >>>>>>> closed those days. > > > > >>>>>>> > > > > >>>>>>> In-person attendees: > > > > >>>>>>> Sakari Ailus > > > > >>>>>>> Kieran Bingham > > > > >>>>>>> Brandon Brnich > > > > >>>>>>> Rouven Czerwinski > > > > >>>>>>> Mehdi Djait > > > > >>>>>>> Bryan O'Donoghue > > > > >>>>>>> Nicolas Dufresne > > > > >>>>>>> Marco Felsch > > > > >>>>>>> Paul Kocialkowski > > > > >>>>>>> Jai Luthra > > > > >>>>>>> Jacopo Mondi > > > > >>>>>>> Benjamin Mugnier > > > > >>>>>>> Beleswar Padhi > > > > >>>>>>> Laurent Pinchart > > > > >>>>>>> Loic Poulain > > > > >>>>>>> Sven Püschel > > > > >>>>>>> Ricardo Ribalda > > > > >>>>>>> Michael Riesch > > > > >>>>>>> Devarsh Thakkar > > > > >>>>>>> Michael Tretter > > > > >>>>>>> Hans Verkuil > > > > >>>>>>> > > > > >>>>>>> Remote attendees: > > > > >>>>>>> Yemike Abhilash Chandra > > > > >>>>>>> Rishikesh Donadkar > > > > >>>>>>> Jackson Lee > > > > >>>>>>> Dave Stevenson (tentative) > > > > >>>>>>> > > > > >>>>>>> > > > > >>>>>>> Agenda (tentative): > > > > >>>>>>> > > > > >>>>>>> 8:45-9:20: Arrive, settle in > > > > >>>>>>> > > > > >>>>>>> 9:20-9:30: Short intro (Hans Verkuil) > > > > >>>>>>> > > > > >>>>>>> 9:30-9:45: Status of ISP support in V4L2 > > > > >>>>>>> Presenter: Laurent Pinchart > > > > >>>>>>> Description: Summary of ISP-related development in V4L2 since the last > > > > >>>>>>> Linux Media Summit. This includes a brief overview of technical > > > > >>>>>>> developments, and a summary of the efforts to engage with vendors. > > > > >>>>>>> > > > > >>>>>>> 9:45-10:45: V4L2 Stateless Video Encoding uAPI Progress Update > > > > >>>>>>> Presenter: Paul Kocialkowski > > > > >>>>>>> Description: An update on the ongonig work to support stateless codecs in V4L2. > > > > >>>>>>> Some of the remaining open topics will be presented and discussed. > > > > >>>>>>> > > > > >>>>>>> 10:45-11:00: break > > > > >>>>>>> > > > > >>>>>>> 11:00-11:30: Vulkan Video Codecs > > > > >>>>>>> Presenter: Nicolas Dufresne > > > > >>>>>>> Description: Vulkan video codecs: what are the viable options for Linux Media > > > > >>>>>>> and what is in preparation outside of our subsystem. The second aspect is > > > > >>>>>>> informative as these discussions don't seem to lean toward our subsystem as the > > > > >>>>>>> foundation. But I think it's rather useful for everyone to understand why and > > > > >>>>>>> what is included. > > > > >>>>>>> > > > > >>>>>>> 11:30-12:00: Protected Video playback on i.MX8MQ > > > > >>>>>>> Presenter: Rouven Czerwinski > > > > >>>>>>> Description: Introduction to protected video playback > > > > >>>>>>> on i.MX8MQ and missing bits for linux-media & protected heap interoperability. > > > > >>>>>>> > > > > >>>>>>> 12:00-13:30: Lunch > > > > >>>>>>> > > > > >>>>>>> 13:30-14:00: HDCP support for HDMI receivers > > > > >>>>>>> Presenter: Hans Verkuil > > > > >>>>>>> Description: I have been working on adding HDCP support for HDMI receivers. > > > > >>>>>>> Specifically the HDCP negotiation between sources and sinks. > > > > >>>>>>> > > > > >>>>>>> 14:00-14:30: AI patches > > > > >>>>>>> Presenter: Sakari Ailus > > > > >>>>>>> Description: What is our policy w.r.t. AI generated patches? > > > > >>>>>>> > > > > >>>>>>> 14:30-15:00 Overview of Media CI: where do pipelines run? > > > > >>>>>>> Presenter: Ricardo Ribalda > > > > >>>>>>> Description: How are jobs in pipelines assigned? How does the infrastructure > > > > >>>>>>> for Media CI work? Are there things that can be tweaked to make it more > > > > >>>>>>> reliable? > > > > >>>>>>> > > > > >>>>>>> 15:00-15:15: Break > > > > >>>>>>> > > > > >>>>>>> 15:15-16:15: Discussion of the media subsystem development process > > > > >>>>>>> Presenter: Hans Verkuil > > > > >>>>>>> Description: Review of the multi-committer model: current status and next steps. > > > > >>>>>>> Are there any bottlenecks, any ideas for improvements, w.r.t. the development process? > > > > >>>>>>> > > > > >>>>>>> As you can see, there is still some available time for other topics. > > -- > Regards, > > Laurent Pinchart