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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 7DAF7C3A59C for ; Fri, 16 Aug 2019 08:31:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F3B6520644 for ; Fri, 16 Aug 2019 08:31:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726755AbfHPIbR (ORCPT ); Fri, 16 Aug 2019 04:31:17 -0400 Received: from lb3-smtp-cloud9.xs4all.net ([194.109.24.30]:45917 "EHLO lb3-smtp-cloud9.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726596AbfHPIbQ (ORCPT ); Fri, 16 Aug 2019 04:31:16 -0400 Received: from [192.168.2.10] ([46.9.232.237]) by smtp-cloud9.xs4all.net with ESMTPA id yXddh13qWzaKOyXdihlM1I; Fri, 16 Aug 2019 10:31:14 +0200 Subject: Re: [ANN] Topics for a media summit in Lyon in October To: Tomasz Figa , Sakari Ailus Cc: Linux Media Mailing List , Alexandre Courbot , Laurent Pinchart , Jacopo Mondi References: <010ba9ce-bac9-6f0c-f128-4f163a7d8ea7@xs4all.nl> <8f49d24c-9074-a988-2ba4-23f4cd2e6fcb@xs4all.nl> From: Hans Verkuil Message-ID: <9adc0b1b-3e8b-348d-e28f-8523c08fa122@xs4all.nl> Date: Fri, 16 Aug 2019 10:31:09 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4wfOb0Fh9FHR9NoxMFAC4bsZ1GF8dmoSmap0V9T2rAxhHGkxV/G3MbIIZeVHTtiBkgbKX8oQaGTCipZHWtxfqPD4vh21w/oozs61TT2Oe29KNy5OTPo7bj RcBBAfBsz8RrVFKeBQDqZpfV6bvXRGFp/CVKHhl/8PSNqkE6dSR9v8RT5oLYdIIROmh9QR5fmXw3aRWgTtN0ccQrHpNvmWJCOS81lXWs82AyScGI1oqaByHd es84KI5tWH+49DXR1qk2en+Kg8MmTGEEkCfGKJ9Y5VuKqp6QS/UzLuvelTvxChmP1hCcf4D/Rv0VoWnwgBvxWLj1gG4T6/JVSnmzpKbkkpuFgZ3lSWBXq/Gm fTL5xEyT Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On 8/16/19 10:22 AM, Tomasz Figa wrote: > On Fri, Aug 16, 2019 at 5:10 PM Hans Verkuil wrote: >> >> On 8/16/19 10:06 AM, Hans Verkuil wrote: >>> Rather then discussing topics for a meeting under the subject 'Lisbon' >>> let's start a new thread referring to the right place :-) >>> >>> I will try to organize a room, either during the ELCE or (if that doesn't >>> work) perhaps on the Thursday afterwards. If that's going to be a problem >>> for someone, please let me know. >>> >>> I do need to know how many people I can expect. I have the following >>> confirmed attendees (and please reply if you are not listed!): >>> >>> Alexandre Courbot >>> Tomasz Figa >>> Jacopo Mondi >>> Laurent Pinchart >>> Hans Verkuil >>> >>> I know there were more who mentioned on irc that they would attend, >>> but it is easier to keep track if I have it in an email. >>> >>> Topics posted under the previous thread: >>> >>> Tomasz: >>> >>> I would want to discuss various v4l2_buffer improvements, e.g. >>> - DMA-buf import with plane offsets, >>> - unifying the buffer structs for M and non-M formats, >>> - ability to import different FDs with offsets for non-M formats if the >>> layout matches driver expectations, etc. >>> >>> Besides that, I would be interested in the general idea on handling >>> complex cameras in the Linux kernel in spite of the remaining V4L2 >>> limitations, e.g. >>> - combinatorial explosion of /dev/video nodes, >>> - significant ioctl overhead, >>> - huge amount of historical legacy making the driver and userspace >>> implementations overly difficult and prone to repetitive mistakes, >>> - the above also limiting the flexibility of the API - formats, frame >>> rates, etc. set using distinct APIs, not covered by Request API, with >>> non-failure "negotiation hell", etc. >>> - lack of fences, etc. >> >> Tomasz, I am not sure if this is suitable for a media summit: my feeling >> is that this is much more suitable for a three day brainstorming session. >> >> My 'roadmap' was to get the codec support sorted first, then start working >> on this. > > I mostly dumped the topics I had in my head, leaving out the codecs as > the obvious thing that people are already planning to talk about. > > That said, there's been more interest in having proper Linux drivers > for camera capture IFs and ISPs and also a lot of feedback about the > issues I listed above. I'm afraid that if we don't start looking into > them early enough, we're going to end up in the same state as with > codecs where we're few years too late or even in the worst case just > the interest fading away. :( I agree that this shouldn't wait too long. And my view is that we should start working on this later this year. I suspect that I should be able to spend time on this in 1-2 months since it looks like the codec work should be mostly complete by then. Regards, Hans > > I guess we could try to organize a separate session on another day for > this, though. +Sakari Ailus who might be also interested in this. > > Best regards, > Tomasz > >> >> Regards, >> >> Hans >> >>> >>> Jacopo: >>> >>> Apart from discussing libcamera and hope we could kickstart a review of >>> its API, I would like to re-start discussing multiplexed stream support, >>> but that would require Sakari to be there, something I'm not certain >>> about. Sakari? >>> >>> Alexandre: >>> >>> If Collabora/Bootlin is there, I'd certainly want to discuss stateless >>> codecs, in particular m2m codec helpers and finalize the specification >>> in general. >>> >>> Regards, >>> >>> Hans >>> >>