From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 244A53FD159 for ; Tue, 28 Apr 2026 13:00:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777381255; cv=none; b=A528Ly65j5v0WwgnM0rBMBdhzRW2wRNIshRN1MYT+DuttafM8CVVx099jNUKdEDW1A5USzFZTpMbGk2KnmwyzHLLRF7pKoPyBOj7Wrh6pHopbDEA37xjzQyu7erDK7H5LrXlfan9RNMiu85uu925zwuuPLYJQQrxw8k3u2JkBNg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777381255; c=relaxed/simple; bh=ieb2r/twWnV/isBnzuwPMiRmz8sg8UZIvfG51cjzCps=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=HvP/zp6iUMLIG9rTB+NzDcHYjlkiBUT7WcQL0XLJ7uXg+1+L7vMbX6x5Wv+pM+jIAmWLNNp1nFAdHw9TNUfW7ejxC9feAnIheEY16JKgL9t7c7HJlr7awgUPTBdv9jEbqWgu0kojd3b3cqRUMHErUCvwg5K7KIjA+zxdJCeM6kU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fXgZQng4; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fXgZQng4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F162C2BCAF; Tue, 28 Apr 2026 13:00:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777381253; bh=ieb2r/twWnV/isBnzuwPMiRmz8sg8UZIvfG51cjzCps=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=fXgZQng4x0qqqlaRX7YTFAhT1s3UtMc9V7b4yEGEULHMcsUhuNq+0l/kznWDAC8K9 3xkNQsIakjqKkx7pPBASfn8Dytw+keXMFvHItmGt6QlarMLX9G3ZyuM1ECZ3Iiu/Nt nIltKjVyfz2ncgORJI4wS4uunpVH6lKwMf8bYGleoKX0x6egtojLLznWzHbuPWpjNg TY1xS+eEdyjkck6mf78AB+fgF0jJYRnbmktQ+hq5rtnPX3PaXq5E1+bRomZWod11Xm 5YMVrJbAMWCIW9nwg52Qon2iWBYbvccgCpZlzDgsnM6lsvM8stlTf+Sfme9BWId8wQ FqW7ApGAGg4mQ== Message-ID: <77ea77b9-5503-40b2-882b-e96e30028c43@kernel.org> Date: Tue, 28 Apr 2026 15:00:44 +0200 Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [ANNv4] Media Summit on May 26th in Nice, France To: Jacopo Mondi , Laurent Pinchart Cc: Loic Poulain , Michael Riesch , Ricardo Ribalda , Nicolas Dufresne , Linux Media Mailing List , Mauro Carvalho Chehab , Sean Young , Sakari Ailus , =?UTF-8?Q?Niklas_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 , =?UTF-8?Q?Sven_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 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> From: Hans Verkuil Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 4/28/26 14:30, Jacopo Mondi wrote: > 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 ? If the number of people can be kept low (say <= 6), then it shouldn't be a problem to just find a hotel restaurant or similar, close to the place of the media summit, and just sit together. Who would be the key people for this? And who are 'nice to have'? :-) I think I probably fit more in the latter category than the first. Regards, Hans > > >>>>>> 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 >